Ethiopian Journal of Biological Sciences

ISSN: 1819-8678

Official Journal of the Biological Society of Ethiopia

Indexed and abstracted by CABI AJOL

Vol. 17, 2018 Addis Ababa (Supplementary) Ethiopia ETHIOPIAN JOURNAL OF BIOLOGICAL SCIENCES VOLUME 17, SUPPLEMENTARY (2018)

EDITORIAL BOARD Editor-in-Chief Prof. Seyoum Mengistou, Dept. of Zoological Sciences, AAU PO Box 81176, Addis Ababa, Ethiopia Tel. +251-11-123 68 40 Editor Prof. Zerihun Woldu, Dept. of Biology and Biodiversity Management, AAU

Associate Editors Prof. Abebe Getahun, Dept. of Zoological Sciences, AAU Dr. Diriba Muleta, Institute of Biotechnology, AAU Dr. Fassil Assefa, Dept. of Microbial, Cellular and Molecular Biology, AAU Dr. Mekuria Lakew, Dept. of Microbial, Cellular and Molecular Biology, AAU Dr. Tamrat Bekele, Dept. of Plant Biology and Biodiversity Management, AAU Dr. Tesfaye Bekele, Ethiopian Environment and Forest Research Institute Dr. Tileye Feyissa, Dept. of Microbial, Cellular and Molecular Biology, AAU Editorial Assistant Miss Abenet Girma, The Biological Society of Ethiopia

INTERNATIONAL ADVISORY BOARD Dr. Amha Belay, Earthrise Nutritionals, USA Dr. Ingvar Backeus, Uppsala University, Sweden Dr. Trygve Berg, Agricultural University of Norway, Norway Prof. Ib Friis, Copenhagen University, Denmark Dr. Coert Geldenhuys, Forestwood cc, South Africa Prof. Tore Godal, GAVI, Switzerland Prof. Kunle Kassim, Howard University, USA Dr. Wojciech J. Pulawski, California Academy of Sciences, USA Dr. Duane A. Schlitter, Texas A&M University, USA Dr. Melanie Stiassny, American Museum of Natural History, USA Dr. Tewolde Berhan Gebre Egziabher, Ministry of Environment, Forest and Climate Change, Ethiopia Prof. Holm Uibrig, Dresden University of Technology, Germany Prof. Zemede Asfaw, Addis Ababa University, Ethiopia Prof. Pei-Yi Chu, Changhua Christian Hospital, Changhua, Taiwan, R.O.C.

© The Biological Society of Ethiopia, 2018

ETHIOPIAN JOURNAL OF BIOLOGICAL SCIENCES VOLUME 17, SUPPLEMENTARY (2018)

CONTENTS

Preface ------iii–iv

Review of the history, and nomenclature of and the objectives and expectations of the international workshop on (Welw.) Cheesman ------1–23 Sebsebe Demissew and Ib Friis

Trends and gaps in enset (Ensete ventricosum (Welw.) Cheesman research ------25–36 Masresha Fetene and Getahun Yemata

The centre of origin and domestication of Ensete ventricosum (Welw.) Cheesman and its phylogenetic relationship to some species ------37–49 Endashaw Bekele

Enset (Ensete ventricosum, ) ethnobotany: Research status, gaps and key messages ------51–62 Zemede Asfaw

Improving indigenous knowledge of propagation for the development of enset agriculture: Promoting farmers’ adaptation capacity to climate change ------63–73 Laila M.Karlsson, Abitew Lagibo Dalbato and Tamado Tana

Biotechnological studies on enset (Ensete ventricosum (Welw.) Cheesman)), a food security staple food crop of Ethiopia ------75–101 Genet Birmeta

Status and future prospects of research on diseases of enset (Ensete ventricosum) and their management ------103–119 Adane Abraham

Land-use changes in the enset-based agroforestry systems of Sidama, southern Ethiopia, and its implications for agricultural sustainability ------121–132 Tesfaye Abebe

Diversity, challenges and management of enset (Ensete ventricosum (Welw.) Cheesman) by Kembatta people, southern Ethiopia ------133–161 Melesse Maryo, Sileshi Nemomissa and Tamrat Bekele

Achievements, experiences and strategies on enset (Ensete ventricosum (Welw.) Cheesman) research in Ethiopia ------163–189 Zerihun Yemataw, Sadik Muzemil, Agedew Bekele and Eshetu Derso

Relevant research questions on the crop physiology of enset ------191–199 P.C. Struik

A perspective to enhance innovative research with emphasis on varietal diversity and sustainable utilization of enset (Ensete ventricosum) ------201–209 Paul Wilkin, Aaron Davis, Sebsebe Demissew, Tom Etherington, Mark Goodwin, Pat Heslop-Harrison, Trude Schwarzacher and Kathy Willis

Addis Ababa declaration on enset ------211–213

Guidelines for Contributors

© The Biological Society of Ethiopia, 2018

Ethiop. J. Biol. Sci. 17(Suppl.): iii–iv, 2018 © The Biological Society of Ethiopia, 2018 ISSN: 1819-8678 PREFACE This supplementary issue of the Ethiopian Journal of Biological Sciences is dedicated to the International Workshop on “enset (Ensete ventricosum) for Sustainable Development: Current research trends, gaps and future direction for a coordinated multidisciplinary approach in Ethiopia” that was held between Oct 17 and 18, 2016 at Addis Ababa, Ethiopia. Introduction - Enset (Ensete ventricosum) is a multipurpose crop providing a range of services such as food, feed, medicine, ritual, fiber and other ecological services such as soil protection and water infiltration. The different uses are attributed to the existence of different enset varieties developed by farmers. Although enset is distributed in the wild throughout much of central, eastern and southern Africa, it has only been domesticated and cultivated in Ethiopia with its highly developed farming system. It is also known that currently of the total number of the Ethiopian population estimated to be about 100 million, about one-fifth of which about 20 million depend on this crop mainly in the Southern Region and adjoining areas in Oromia and Gambella Regions. Despite the important attributes of the crop such as the harvesting throughout the year, storage over a long period, high yield per unit area and the enset system having a high human carrying capacity compared to cereal growing regions, the enset agriculture was deprived of the research attention it deserved compared to cereal agriculture. Cognizant of workshops held in the past, the aim of the workshop was to bring together enset researchers from both the natural and social sciences in order to capture the wealth of vital information from various research areas carried out in the past four to five decades, identify the research gaps in their areas of expertise and suggest the way forward. During the workshop, there were 47 participants from the Ministry of Agriculture (at the federal and regional levels), Ministry of Science and Technology, stakeholders representing policy makers; Universities (Addis Ababa, Arba Minch, Haramaya, Hawassa, Wolayita, Wolkite in Ethiopia, the University of Wageningen, the Netherlands and Swedish University of Agricultural Sciences, Uppsala, Sweden), the Ethiopian Biodiversity Institute, Southern Agriculture Research Institute); and other invited guests. Twenty two papers were presented and of which 12 are published in this supplementary issue. These papers presented wealth of information available from research carried out in the last 40 years and also presented challenges iv Preface and gaps. Over all it was acknowledged that the research that has been going on mainly in natural science disciplines have been carried out largely in isolation. Science-Policy Interface - One of the major problems in Ethiopia and elsewhere in developing countries is the lack of communication between researchers and policy makers and hence the direct impact of research results on policy is rare and far in between. Thus, there is a need to work a mechanism to have a workable science-policy interface. Research results on enset have not made a major impact on policy so as to make enset research high on the research agenda both at the national and regional levels. At the end of the workshop participants agreed on the need: to have a multidisciplinary approach in order to develop a sustainable future for enset system and the livelihood of communities depending on it; towards developing a science-policy interface where research results influence policy through effective communication; for policy makers to use research results to make informed decisions in promoting enset as one of the important indigenous crops and to take steps to recognize/identify a Centre of Excellence on Enset in Eastern Africa in general and in Ethiopia in particular in a similar way as there is Centre of Excellence on Yam Research in West Africa; to follow the implementation of the various points indicated in the Addis Ababa declaration on enset that is included at the end of this supplementary volume. Sebsebe Demissew, National Herbarium, Department of Plant Biology and Biodiversity Management, College of Natural Sciences, P.O. Box 3434, Addis Ababa Ethiopia: e-mail: [email protected] Further information is available from: http://enset-project.org/

Ethiop. J. Biol. Sci. 17(Suppl.): 1–23, 2018 © The Biological Society of Ethiopia, 2018 ISSN: 1819-8678 REVIEW OF THE HISTORY, TAXONOMY AND NOMENCLATURE OF ENSETE AND THE OBJECTIVES AND EXPECTATIONS OF THE INTERNATIONAL WORKSHOP ON ENSETE VENTRICOSUM (WELW.) CHEESMAN

Sebsebe Demissew1,2,3* and Ib Friis3,4

ABSTRACT: The history, taxonomy and nomenclature of the Ensete and particularly the Ethiopian enset, E. ventricosum, have been put in African and global perspective; although the genus Ensete occurs widespread in Africa, on Madagascar and in parts of Asia, and the species E. ventricosum is widespread in tropical Africa, the early history of its scientific study is closely linked to Ethiopia, where it is domesticated. A full synonymy of the genus Ensete has been compiled in an appendix. The objectives of the International Workshop on “Enset (Ensete ventricosum) for Sustainable Development: Current Research Trends, Gaps and Future Direction for a Coordinated Multidisciplinary Approach in Ethiopia” are outlined. It is intended to bring together researchers from both the natural and social sciences in order to capture the wealth of vital scientific information from various research areas carried out in the past four to five decades and identify research gaps in their areas of expertise. On the way forward to reach a consensus on the need to fill the gaps identified, for a concerted effort for a multidisciplinary approach, the scientific results from research to feed into policy and the identification of a centre of excellence for enset research and its sustainable use through a declaration.

Key words/phrases: Enset (Ensete ventricosum), Research and research gaps, Unique Ethiopian crop, Way forward.

INTRODUCTION Enset, with the scientific name Ensete ventricosum (Welw.) Cheesman, is a very important crop in Ethiopia, and it was first described in the scientific literature as an Ethiopian food plant. It is therefore of interest to place it in a wider context, historical and geographical. In the Flora of Ethiopia and Eritrea the enset plant is described like this in the family Musaceae (Lye and Edwards, 1997): a robust perennial monocot plant with swollen base up to 3 m in circumference and the pseudo-trunk (false stem, formed of leaf- bases) growing to about 12 m tall, but usually less. Leaves in a basal rosette

1 National Herbarium, Department of Plant Biology and Biodiversity Management, College of Natural and Computational Sciences, Addis Ababa University, P.O. Box 3434, Addis Ababa, Ethiopia. E--mail: [email protected] 2 Gullele Botanic Gardens 3 Honorary Associate, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK. 4 Natural History Museum of Denmark, Universitetsparken 15, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark. *Author to whom all correspondence should be addressed

2 Sebsebe Demissew and Ib Friis when young, oblong to oblanceolate, 7 x 1 m, bright to dark-green, with midrib and other parts of the leaf sometimes pale to dark red or dark purple, rarely the whole lower side of the leaf reddish (Fig. 1a).

c a b

Fig. 1. Habit (left) and varied habitat (b and c). The Flora of Ethiopia and Eritrea has recorded the scientific naming of the enset plant from the point of view of Ethiopia and left out information from the rest of the distribution area, apart from the original collection of Musa ventricosa Welw. made in Angola. Here, it is sufficient to give the same information in slightly corrected form and with full titles of the articles, books and journals in which the observations were published and new names proposed. However, the full story of how Ensete ventricosum got its scientific name is an interesting tale from history of science, and it is narrated in detail in Appendix 1. Ensete ventricosum (Welw.) Cheesman in Kew Bulletin 2(2): 101. 1948 [1947 publ. 12 Apr 1948]; Musa ventricosa Welw. [Welwitsch] in Annaes do Conselho Ultramarino, Parte nao official 1: 587 [no. 45] (1859) - type: Angola, Pungo Andongo, rocky place at small stream, Welwitsch 6447 (LISU, BM, K isotypes, specimen at K selected lectotype by Baker and Simmonds, 1954: 405). Musa ensete J.F. Gmelin in Caroli a Linné. Systema naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima tertia, aucta, reformata, Vol. 2(2): 567 (1791); Ensete edule P. F. Horaninow, Prodromus monographiae

Ethiop. J. Biol. Sci., 17(Suppl.): 1–23, 2018 3

Scitaminarum: 40. (1862) – type: Ethiopia, plates between p.36 and 37 in J. Bruce, Travels to discover the source of the Nile, in the years 1768, 1769, 1770, 1771, 1772, and 1773: in five volumes. Volume 5. Select specimens of natural history, collected in travels to discover the source of the Nile, in Egypt, Arabia, Abyssinia, and Nubia (1790). E. ventricosum (Welw.) Cheesman var. montbeliardii (Bois) Cufodontis in Bulletin du Jardin Botanique National de Belgique 42(3, supplementum, “Enumeratio plantarum aethiopiae spermatophyta”): 1593 (1972); Musa ensete Gmel. var. montbeliardii Bois in Bulletin du Muséum National d’Histoire Naturelle, 2e série, Vol. 2: 688 (1931) – type: Ethiopia, Shewa, near Addis Abeba, M. De Scey-Montebeliard s.n. (no original material traced). For the rest of Africa, synonyms of Ensete ventricosum have a much more complicated history, with synonyms from almost all parts of the continent. In the taxonomy of the species of Ensete in Africa and Asia not all questions have been solved. In Appendix 2, there is a review of the recent views on the synonyms of Ensete ventricosum, as well as of the two other currently recognized species of Ensete in Africa, E. homblei (De Wild.) Cheesman and E. livingstonianum (J. Kirk) Cheesman, of the three Asian species, E. glaucum (Roxb.) Cheesman, E. superbum (Roxb.) Cheesman and E. lasiocarpa (Franchet) Cheesman and of the one Malagasy species, E. perieri (Claverie) Cheesman. The review of the entire genus in Appendix 2 is a critical compilation of general information in Väre and Häkkinen (2011), in Lebrun and Stork (2012), in WCSP (2018) and other sources for specific details, mainly from regional floras. These sources do not always agree, underlining the need for more general taxonomic studies of Ensete. In the context of the future research proposed in this workshop, it is relevant to know also about the other species in the genus. As an example of the unresolved taxonomic problem in relation to Ensete, one can mention the taxonomic status of the Golden Lotus , a sacred plant to Buddhist monks in the tropical region of Yunnan and first described as Musa lasiocarpa Franchet in 1889, but transferred to Ensete by Cheesman as E. lasiocarpa (Franchet) Cheesman (1948) and to a monotypic genus, Musella (Franchet) H. W. Li (1978), as M. lasiocarpa (Franchet) H. W. Li (1978); later again Liu, Kress and Li (2010) found it to be part of the clade I(B) of Ensete, as a sister group to the three African species. However, further molecular studies (Li et al., 2010) showed it in an ambiguous taxonomic position, both as a sister group of the African species of Ensete

4 Sebsebe Demissew and Ib Friis and as a sister group of all species in the genus. In the former case, the species should remain in Ensete, in the latter case, the genus Musella should be re-erected; thus even the generic limits of Ensete remains unsolved for the moment. It has been suggested by Laurent-Täckholm (1952) and supported by Baker and Simmonds (1954) that enset cultivation in Northeastern Tropical Africa, particularly in Nubia and possibly also in Northern Ethiopia, may go back thousands of years, to Neolithic time, in areas once in close contact with Egypt. The main evidence for this theory was pictorial representations on pottery; these pictures show with a number of characteristic feature of enset. However, Laurent-Täckholm’s interpretation of the paintings as representing enset has not been supported by further evidence, and the theory has been rejected by most later researchers, for example Simoons (1965), who argued that evidence for enset cultivation in ancient Egypt is highly inconclusive, that the cultivation of enset for food in northern Ethiopia must be viewed as recent, and that peoples of southwestern Ethiopia are the likely candidates for enset domestication. Taye Bezuneh and Asrat Feleke (1966) and Taye Bezuneh et al. (1967) noted that enset has been cultivated as a food and fiber crop in Ethiopia for several centuries and Brandt (1996) attested the fact that its domestication and use as a food and fiber crop is restricted to Ethiopia. It is also documented that Enset farming is believed to be indigenous to Ethiopia (Ehret, 1979) and is a common feature of the farming systems in the south and south-western parts of the country and constitutes what is often termed the ‘enset system’ (Desalegn Rahmato, 1996). It is worth noting that Bruce (1790) reported that from conversations with people around Lake Tana he had, he was convinced that the enset was native in humid areas of southwestern Ethiopia (see Appendix 1). The various theories regarding domestication and early cultivation of enset was summarised on an ethnological background by Westphal (1975), but without a decisive conclusion. More ethnological and archaeological evidence for the early domestication of enset would be interesting (Fig. 1b and c). Uses Enset is a multipurpose crop providing a range of services such as food, forage, medicine, ritual, construction and environment protection, food, medicine, purposes. The different uses are attributed to the existence of different enset varieties (Yemane Tsehaye and Fassil Kebebew, 2006).

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 Enset is primarily used as a starch crop as food in the form of amicho, where the inner part of the eaten boiled. Its products are also used for other purposes (Fig. 2) such as kocho (fermented material obtained from a mixture of decorticated leaf sheath and corm), bulla (water insoluble starchy product obtained by squeezing the scrapped leaf sheath and corm).  However, there is also a long tradition for using enset as a vegetative ornamental plant. Bois (1931) quotes a French informant, who had lived in Ethiopia for decades, for information about the many varieties of enset with different uses, some for food and some for ornamental and social purposes. He claimed to have been informed about 40 forms with ornamental uses, many of which with more or less red leaves, either red from the beginning of their growth or with the red leaves developing with age. The red-leaved forms, he reported, were particularly appreciated among the Gurages, who would plant them near their houses.  A few varieties of enset are reported to have medicinal and religious (ritual) significance for preventive treatment, healing and other therapeutic purposes, and as protection against evil spirits.  The leaves are the most widely used of all wrapping material, particularly for butter and other products that need to be kept cool and moist. Temporary ovens for baking special bread are made out of Enset leaves on which smouldering dung cakes are placed.  In Ethiopia the fiber of the plant is also widely used for making bags and ropes and for basketry. The strength is, however, less than that of Musa textilis or Agave, but is said to be resistant to sea water. It is estimated that about 600 tons of enset fiber per year is sent to the factories (Brandt et al., 1997).  The male flowers produce copious pollen and the female much nectar, which attract large numbers of honeybees (although enset plants are only allowed to flower in the wild).  Enset has also a number of socio-cultural importance, serving as a symbol for expressing condolence and other rituals (Gebre Yntiso, 1996; Shigeta, 1997; Worku Nida, 1996).

6 Sebsebe Demissew and Ib Friis

a b

d c

Fig. 2. Some uses of enset. a: food for humans; b: feed for cattle; c: for medicine and d: for fiber. Enset has a perennial leaf canopy over the soil and a heavy mulch cover from leaf litter. Owing to the large leaves and ‘open-tube like’ leaf architecture, enset plants cultivated on hill slopes and can intercept rainwater and reduce soil erosion (Tesema Chekun, 1998; Tadesse Kippie, 2001). Important attributes Enset has a number of important attributes as a cultivated plant. First, the plant can be harvested at any time during the year and be harvested at any stage over a several year period. Second, enset foods can be stored for long

Ethiop. J. Biol. Sci., 17(Suppl.): 1–23, 2018 7 periods. Third, the crop produces the highest starch yield per unit land area of any crop in Ethiopia. Fourth, the enset system has the highest human carrying capacity as evidenced by the population density of the enset growing regions as opposed to cereal growing regions. Owing to all these qualities, the enset farming system provides a long-term, sustainable food supply, with potentially low off-farm input. However, it responds well to fertilization and high nitrogen inputs give increased yields; as a perennial crop, human waste is sometimes used in young plantations. Enset suffers from a wide range of fungal, bacterial, viral and nematode infections, most of which are poorly characterized but lead to poor yields in second crops grown in the field. Bacterial wilt (Xanthomonas campestris pv. musacearum) has been a serious problem (Dagnachew Yirgou and Bradbury, 1968; 1974; Adane Abraham, 2018). There is probably some genetic variation in susceptibility between genotypes. Strict biosecurity measures including disinfection of tools after use on each plant, and removal and burning of infected material and replacement by other crops for several years, supported by intensive educational programmes and distribution of disease-free planting material, can control bacterial wilt and reduce disease pressure from other pathogens. In cultivation, enset is planted at any time of the year and is traditionally propagated vegetatively. Unlike species in the genus banana (Musa), in which the stems are branched below ground and produce a clump of shoots above ground, it is widely reported in the literature that in the genus Ensete the entire plant is unbranched and monocarpic, meaning that each plant is supposed to die after flowering (Lock, 1993; Lock and Diniz, 2010). Indeed, most enset accessions do not produce suckers, although there are observations to the contrary, that some varieties produce suckers. This is interesting from a taxonomic, as well as from a practical point of view, and should be studied and reported on in more detail. The enset is propagated from cuttings or sometimes the outer part of harvested (after removal of the starchy centre), which are filled with manure and replanted. Fields are initially planted at high density, and thinned each year (to typically <1000 plants/ha) with the removed plants being used for animal feed, food or replanted in another field. There are substantial differences in agronomy between areas, although the contributions of genetic, environmental and cultural factors are not known. As mentioned above, the enset plant is monocarpic, flowering after 3 to 6 years (not greatly synchronized), and gives the highest starch yield when harvested as soon as floral initiation is observed. Early harvest gives poor yields of starch since the plant only

8 Sebsebe Demissew and Ib Friis stores reserves in the period leading up to flowering, and overexploitation of young plants has been a problem. There are several hundred named varieties or landraces of enset. The recent phylogenies show that he genus is relatively sharply divided into Asian and African members, but little is known about the potential hybridization of these species, and experiments with possible gene transfer in breeding programmes has to our knowledge not been done. An overview of all described species is given in Appendix 2, but some of the species are not well defined. Among the species on the African mainland, E. ventricosum is particularly distinctive by its large seeds, which may be up to 23 mm in largest diameter (Lock and Diniz, 2010), while the seeds of the two other African species, E. livingstonianum and E. homblei, are less than 9 mm in largest diameter and it is possible that they are forms of one single variable species (Lock and Diniz, 2010). Ensete is one of two genera, along with Musa (and perhaps Musella, if this is considered distinct from Ensete), in the Musaceae. Ensete ventricosum is a fertile diploid with 2n = 18, with a genome size similar to Musa acuminata, and can be easily propagated by seed, as can be observed from the considerable number of seedlings around an enset plant, which has been allowed to develop fruits in the wild. Despite all these merits, the enset agriculture was deprived of the research attention it deserved and was highly neglected as compared to the attention given to cereals. Much of energy and financial resources was devoted to the improvement of cereals by various successive governments. In addition, when the Vavilov Centre of origin for cultivated crops was identified in the 1950s, this crop was not among the ones considered important. The information available traditionally (folk taxonomy) has not been adequately captured and related with modern molecular knowledge (Admasu Tsegaye, 2002). Enset needs further research and even breeding programmes to ensure it can maintain its place among high yielding, sustainable and perennial starch staple crops that have cultural acceptance. Research and research gaps on enset In the workshop over 20 scientific papers in thematic areas in both Natural and Social Sciences including: Agronomy, Agroforestry, Ethnobotany, Genetics, Modelling, Industrial application, Food security, Nutrition and Dietary aspects, and Socio-economics, were presented. However, of all the papers presented only 12 are included in this supplementary issue. These include articles on: trends and gaps (Masresha Fetene and Getahun Yemata, 2018); the centre of origin and domestication (Endashaw Bekele, 2018);

Ethiop. J. Biol. Sci., 17(Suppl.): 1–23, 2018 9 ethnobotany (Zemede Asfaw, 2018); improving indigenous knowledge (Karlsson et al., 2018); biotechnological studies (Genet Birmeta, 2018); physiology (Struik, 2018); diseases (Adane Abraham, 2018); diversity, challenges and management (Melesse Maryo et al., 2018); land use and agroforestry systems (Tesfaye Abebe, 2018); experiences and strategies (Zerihun Yemataw et al., 2018) and enhancing innovative research (Wilkin et al., 2018). Each of these themes are presented in detail as individual articles in this issue. Future direction on enset research and the way forward During the workshop a series of paper presentations were made and followed by fruitful discussions. The discussions following the presentations revealed the uniqueness of the crop, the status of its biodiversity in Ethiopia and its potential to become an important food crop and industrial crop in Ethiopia and beyond. At the end of the workshop, there were final discussions, which highlighted and stressed the importance of enset for food security, especially for the rural poor, and the importance for the livelihood and culture of many peoples of Ethiopia. The workshop was concluded by signing a declaration on the future direction where enset research should go, known as the “Addis Ababa Declaration on Enset”, which is attached as declaration at the end. REFERENCES The list includes also papers or books referred to in the appendices, but not works only cited in the synonymies in Appendix 2. Adane Abraham (2018). Status and future prospects of research on diseases of Enset (Ensete ventricosum) and their management. EJBS in this issue. Admasu Tsegaye (2002). On Indigenous Production, Genetic Diversity and Crop Ecology of Enset (Ensete ventricosum (Welw.) Cheesman. Doctoral thesis, Wageningen University, Wageningen. Anonymous (2018). Kew Science: Plants of the World online. http://powo.science.kew.org/ (accessed January 2018). Argent, G.C.G. (1976). The wild of Papua New Guinea. Notes from the Royal Botanic Garden, Edinburgh 35: 77–114. Baker, R.E.D. and Simmonds, N.W. (1954). The genus Ensete in Africa. Kew Bull. 8(3): 405–416. Bois, D. (1931). Bananiers d’Abyssinie a feuilles rouges. Bull. Mus. Natl. Hist. Nat. 2. Sér. 2(6): 688–690. Brandt, S.A. (1996). A model for the origins and evolution of enset food production. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 36–46, (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings of the International Workshop on Enset (1993). Institute of Agricultural Research, Addis Ababa.

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Brandt, S.A., Spring, A., Hiebsch, C., McCabe, J.T., Endale Tabogie, Mulugeta Diro, Gizachew Woldemichael, Gebre Yntiso, Shigeta, M. and Shiferaw Tesfaye (1997). The “Tree against Hunger”: Enset-Based Agricultural Systems in Ethiopia. American Association for the Advancement of Science with Awassa Agricultural Research Center, Kyoto University, Center for African Area Studies and University of Florida, Washington, DC. Bruce, J. (1790). Travels to discover the source of the Nile, in the years 1768, 1769, 1770, 1771, 1772, and 1773: in five volumes. Volume 5. Select specimens of natural history, collected in travels to discover the source of the Nile, in Egypt, Arabia, Abyssinia, and Nubia. Printed by J. Ruthven, for G.G.J. and J. Robinson, Edinburgh and London. Dagnachew Yirgou and Bradbury, J.F. (1968). Bacterial wilt of enset (Ensete ventricosum) incited by Xanthomonas musacearum sp. n. Phytopathology 58: 111–112. Dagnachew Yirgou and Bradbury, J.F. (1974). A note on wilt of banana caused by the enset wilt organism, Xanthomonas musacearum. E. Afr. Agr. Forestry J. 40: 111–114. Delin, W. and Kress, W.J. (2000). Musaceae. In: Flora of China (Flagellariaceae through Marantaceae), pp. 297–313 (Wu, Z.Y. and Raven, P.H., eds.). Vol. 24. Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis. Desalegn Rahmato (1996). Resilience and vulnerability: Enset agriculture in Southern Ethiopia. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 83–106 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings of the International Workshop on enset (1993), Institute of Agricultural Research, Addis Ababa. Ehret, C. (1979). On the antiquity of agriculture in Ethiopia. J. Afr. Hist. 20: 161–177. Endashaw Bekele (2018). The centre of origin and domestication of Ensete ventricosum (Welw.) Cheesman and its phylogenetic relationship to some Musa species. EJBS in this issue. Gebre Yntiso (1996). Economic and socio-cultural significance of enset among the Ari of southwestern Ethiopia. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 119–121 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings of the International Workshop on enset (1993), Institute of Agricultural Research, Addis Ababa. Genet Birmeta (2018). Biotechnological studies on enset (Ensete ventricosum), a food security staple food crop of Ethiopia. EJBS in this issue. Goyder, D. (2014). Lectotypification of Musa livingstoniana (Musaceae). Kew Bull. 69(3): Paper no. 9529 (4 pages). Häkkinen, M. and Väre, H. (2008). Typification and check-list of Musa L. names with nomenclatural notes. Adansonia Sér. 3, 30(1): 63–112. Horaninow, P.E. (1862). Prodromus Monographiae Scitaminarum. Academiae Caesareae Scientarum, St. Petersborg. Joe, A., Sreejit, E. and Sabu, M. (2016). Genus Ensete (Musaceae) in India. Telopea 19: 99–112. Karlsson, L.M., Abitew Lagibo Dalbato and Tamado Tana (2018). Improving indigenous knowledge of propagation for the development of enset agriculture: Promoting farmers’ adaptation capacity to climate change. EJBS in this issue. Laurent-Täckholm, V. (1952). The plant of Naqada. Ann. Serv. Antiq. Egypte 51: 299–312. Lebrun, J.-P. and Stork, A.L. (2012). Tropical African Flowering Plants. Ecology and Distribution. Volume 7: 1 (Limnocharitaceae – Agavaceae).

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Éditions des Conservatoire et jardin botanique Genève, Ville de Genève. Li, L.-F., Häkkinen, M., Yuan, Y.-M., Hao, G. and Ge, ZX.-J. (2010). Molecular systematics of the banana family (Musaceae) inferred from multiple nuclear and chloroplast DNA fragments, with special reference to the genus Musa. Mol. Phylogenet. Evol. 57(1): 1–10. Liu, A.-Z., Kress, W.J. and Li, D.-Z. (2010). Phylogenetic analyses of the banana family (Musaceae) based on nuclear ribosomal (ITS) and chloroplast (trnL-F) evidence. Taxon 59(1): 20–28. Lock, J.M. (1993). Musacea. In: Flora of Tropical East Africa (Polhill, R.M., ed.). A.A. Bakema, Rotterdam. Lock, J.M. and Diniz, M.A. (2010). Musaceae. In: Flora Zambesiaca 13(4), pp. 104–111 (Timberlake, J.R. and Martins, E.S., eds.). Royal Botanic Gardens, Kew, for the Flora Zambesiaca Managing Committee, London. Luu, H.T., Nguyen, Q.D., Vu, N.L., Vo, T.L. (2012). Ensete lecongkeitii (Musaceae) –a new species from Vietnam. Folia Malaysiana 13: 43–50. Lye, K.A. and Edwards, S. (1997). The Family Musacae. In: Flora of Ethiopia and Eritrea, Vol. 6: 317–321 (Edwards, S., Sebsebe Demissew and Inga, H.,eds.). Masresha Fetene and Getahun Yemata (2018). Trends and gaps in enset (Ensete ventricosum (Welw.) Cheesman research. EJBS in this issue. Melesse Maryo, Sileshi Nemomissa and Tamrat Bekele (2018). Diversity, challenges and management of enset (Ensete ventricosum (Welw.) Cheesman) by Kembatta people, Southern Ethiopia. EJBS in this issue. Shigeta, M. (1997). Essence of indigenous sustainability and diversity: Enset system. In: Proceedings of the XIIIth International Conference on Ethiopian Studies, Ethiopia in Broader Perspective, Vol. 3: 883–892 (Fukui, K., Kurimoto, E., Shigeta, M., eds.). 12-17 December, Kyoto. Simoons, F.J. (1965). Some questions on the economic prehistory of Ethiopia. J. Afr. Hist. 6(1): 1–13. Struik, P.C. (2018). Relevant research questions on the crop physiology of enset. EJBS in this issue. Tadesse Kippie (2001). Five Thousand Years of Sustainability? A Case Study on Gedeo Land Use (Southern Ethiopia). Doctoral thesis, Wageningen University, Tree mail Publishers, Heelsum. Taye Bezuneh and Asrat Feleke (1966). The production and utilization of the genus Ensete. Econ. Bot. 20(1): 65–70. Taye Bezuneh, Asrat Feleke and Regassa Bayie (1967). The cultivation of the genus Ensete in Ethiopia. Proc. Soil Crop Sci. Soc. Fla. 27: 133–141. Tesema Chekun (1998). Enset bioengineering: A vegetative measure for social conservation, in the coffee culture of Ethiopia (Abstract). Tesfaye Abebe (2018). Landuse changes in the Enset-based agroforestry systems of Sidama, Southern Ethiopia and its implications for agricultural sustainability. EJBS in this issue. Väre, H. and Häkkinen, M. (2011). Typification and check-list of Ensete Horan. names (Musaceae) with nomenclatural notes. Adansonia sér. 3, 33(2): 191–200. WCSP (2018). World Checklist of Selected Plant Families. Facilitated by the Royal Botanic Gardens, Kew. http://wcsp.science.kew.org/ (Accessed 2018). Westphal, E. (1975). Agricultural systems in Ethiopia. Belmontia, New ser. 4: 1–278 (the enset farming is dealt with on p. 123–163).

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Wilkin, P., Davis, A., Sebsebe Demissew, Etherington, T., Goodwin, M., Heslop-Harrison, P., Schwarzacher, T. and Willis, K. (2018). A perspective to enhance innovative research with emphasis on varietal diversity and sustainable utilization of Enset (Ensete ventricosum). EJBS in this issue. Worku Nida (1996). The Gurage perception of enset. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 132–137 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings of the International Workshop on enset (1993). Institute of Agricultural Research, Addis Ababa. Yemane Tsehaye and Fassil Kebebew (2006). Diversity and cultural use of Enset (Ensete ventricosum (Welw.) Cheesman) in Bonga in situ conservation site, Ethiopia. Ethnobot. Res. Appl. 4: 147–157. Zemede Asfaw (2018). Enset (Ensete ventricosum, Musaceae) ethnobotany: Research status, gaps and key messages. EJBS in this issue. Zerihun Yemataw, Sadik Muzemil, Agedew Bekele and Eshetu Derso (2018). Achievements, experiences and strategies on Enset (Ensete ventricosum (Welw.) Cheesman) research in Ethiopia. EJBS in this issue.

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Appendix 1. The history behind the synonymy of Ensete ventricosum as published in the Flora of Ethiopia and Eritrea There are many discoveries and debates behind the synonymy of Ensete ventricosum, as published in the Flora of Ethiopia and Eritrea, beginning with the oldest records of the name Ensete in scientific literature. We can follow the debate backwards, because the works that improves the taxonomy and nomenclature refer to each other, the younger ones to the older ones. Scientific names have to be based on specific preserved plant material, the so-called types, which help us to fix what the scientists mean by a particular name. That is not an easy task for the enset plants, which are big and difficult to preserve in museums and herbaria. Here we start with the third line in the synonymy: “Musa ensete Gmel. (1791); Ensete edule Horan. (1862) – type: Ethiopia, Icones, p. 47 in Bruce (1790)”, which brings us to the first scientific description of the enset plant, that by James Bruce, based on what he observed himself and heard from people he spoke with during his visit to Ethiopia around 1770, mainly in Gondar and the area around Lake Tana. Bruce stated that the enset plant had been brought to that area from “Narea” (elsewhere in the work often spelt Enarea; he had been informed that it was native in moist areas with swamps and many rivers, located south-west of the kingdom of “Gurague” and north of the kingdom of “Caffa”. On the map, which Bruce published with his Travels, the kingdom of Enarea is located approximately at 8° 30ʹ N and 35° 10ʹ E, which is between the modern towns of Metu and Dembidolo. No material of enset is preserved from Bruce’s visit to Ethiopia, but there are drawings made by his assistant, the Italian artist Luigi Balugani, and these are reproduced in Bruce’s books. “Bruce (1790)” refers to volume 5, Select Specimens of Natural History in the work by James Bruce: Travels to discover the source of the Nile, in the years 1768, 1769, 1770, 1771, 1772, and 1773. Two plates which show the entire enset plants, one in leaf and early flowering and one in late flowering or fruiting, are inserted between page 36 and 37. Bruce argued that the enset plant did not belong to the banana genus, Musa, and he called it Ensete, but gave no name for it in Linnaeus’ system of botanical nomenclature. The next in the history of that line is “Musa ensete Gmel. (1791)”, which refers to a book by the German naturalist J.F. Gmelin, Caroli à Linné, ... Systema naturae per regna tria naturae, secundum classes,ordines, genera, species, cum characteribus, differentiis. Editio decima tertia, aucta, reformata [The systems of the three kingdoms of nature, according to

14 Sebsebe Demissew and Ib Friis classes, orders, genera and species, with differential characters. Edition 13, augmented and revised], Tomus II(2); the name and reference to Bruce is on p. 567. This work is one of many updated versions of Linnaeus’ Systema Naturae, in which descriptions and names of newly discovered plants and animals were incorporated between the already known ones. Gemlin disagreed with Bruce and considered the enset plant to be a banana, Musa, but to acknowledge that he based his name on Bruce’s description and plates, his name for the plant included the word ensete, according to the Linnean principles: Musa ensete Gmel. Next in the history of that line is “Ensete edule Horan. 1862.” Horan. is an abbreviation standing for the Russian botanist Paulus Federowitsch Horaninow, who wrote a book called Prodromus Monographiae Scitaminearum [Forerunner of a monograph of the banana-like plants], published in 1862. He explained on p. 40 how he had studied both living and dried material of the plant at the Royal Botanic Gardens, Kew, to which institutions seeds had been sent from the British Consul to Abyssinia [Ethiopia] in 1753; and Horaninow concluded that it differed from the true bananas of the genus Musa both in features of the flowers and the seeds, for which reason he agreed with Bruce that it was a distinct genus. Horaninow lists the generic name as “Ensete Bruce”, but now the generic name is referred to as “Ensete Bruce ex Horan.” Or, as in Flora of Ethiopia and Eritrea, as “Ensete Horan.” Since there is no tradition in botany that allows the species name to repeat the name of the genus, Horaninow could not use Gmelin’s ensete as a species name, and he therefore coined the name edule, referring to Bruce’s description of how the plant was used for food in Ethiopia. The last point in that line deals with the type material. Two British economic botanists, Richard Eric Defoe Baker and Norman Willison Simmonds, had summarised knowledge about Ensete in a paper, The Genus Ensete in Africa, in Kew Bulletin 8(3): 405-416 (1953). Here they stated that the plates between p. 36 and 41 in the 1790-edition of Bruce’s Travels represented the only material left on which to base the names of Bruce, Gmelin and Horaninow, and that these two plates should be the type (the indication of the pages in Flora of Ethiopia and Eritrea is therefore not completely correct). However, two Finnish botanists, Henry Väre and Markku Häkkinen, have tried to find original material to serve as types of all published names of Ensete and have described the results in their work Typification and check-list of Ensete Horan.-names with nomenclatural notes, published in the journal Adansonia 3. Ser., 33(2): 191-200 (2011). In

Ethiop. J. Biol. Sci., 17(Suppl.): 1–23, 2018 15 this work, they state that the type of Gmelin’s and Horaninow’s names is “pl. 21, figs 1 and 2 (lecto-, designated by Baker & Simmonds …)” and that the plates are found in Volume 6 of Bruce’s Travels. This is strange, as the volume number is wrong for the original edition of Bruce’s Travels, which was originally printed by J. Ruthven for G.G.J. and J. Robinson, and published in Edinburgh and London. In this original publication, the plates are not numbered and the page references given by Väre and Häkkinen are also wrong; their information must be based on a secondary edition of Bruce’s Travels, that printed by Zacharia Jackson in Dublin for P. Wogan, L. White, P. Birne, W. Porter, W. Sleater, J. Jones, J. Moore, B. Dormin, C. Lewis W. Jones, G. Draper, J. Miliken, and R. White [1790-1791]. In this secondary edition, the natural history is in Vol. 6, Ensete is dealt with on p. 45-50, and the two illustrations of the plant are numbered as pl. 21, n.1 and 2. The statement of Baker and Simmonds, based on the original edition of Bruce’s Travels, should stand. Before Horaninow’s work in 1862, another line – the first and second one in the synonymy - had started with the publication of the name “Musa ventricosa Welw. 1859.” The Austrian botanist Friedrich Martin Josef Welwitsch had in Angola, in an area called Pungo Andongo, collected a plant, which he considered a species of Musa; it was collected as a wild plant near a small stream and had his collecting number 6447. The plant was described very briefly and named Musa ventricosa Welw. as no. 45 on p. 587 in an article called Apontamentos phyto-geographicos, in a rare Portuguese journal called Annaes do Conselho Ultramarino. Parte nao official 1: 527-592 (1859). Welwitsch collected many duplicates of his collection and duplicates of this particular one (collection no. 6447) are therefore distributed them to a number of herbaria. Again, indication of the type material is slightly controversial. Welwitsch must have based his description on all the material he collected, of which the largest number of specimens of no. 6447 (7 sheets, mostly with leaves) are at the Portuguese herbarium LISU, and some of them carry descriptions by Welwitsch; for this reason, the authors of the Flora of Ethiopia and Eritrea considered the material at LISU to be holotype, that is the type material, on which Welwitsch had based his description; but Baker and Simmonds have designated as lectotype material of no. 6447 at K, which also had a description by Welwitsch attached. Next in this historical line is “Ensete ventricosa (Welw.) Cheesman. 1947.” This is actually the first line of the synonymy, for that is the name we accept today. Ernest Entwisle Cheesman was an English botanist noted for his

16 Sebsebe Demissew and Ib Friis general work on the family Musaceae at the Royal Botanic Gardens, Kew, in the 1940s. Cheesman finally made it clear that Bruce and Horaninow were right, Ensete and Musa were indeed two different genera, that there are no wild species of Musa in Africa, only Ensete, and that Ensete is distinguished by being strictly monocarpic, has large seeds and that the chromosome set is based on a haploid chromosome number of 9. In a paper in Kew Bulletin 2(2), called Classification of the bananas. 1. The genus Ensete (p. 97-106), he accepted both the name Ensete edule Horan. from Ethiopian plants, and Ensete ventricosum (Welw) Cheesman from Angolan plants, but also 23 other species of Ensete, and based the names in Ensete on species originally described in the genus Musa. He also clearly noted that not all of these might stand further studies, particularly studies, which might well demonstrate that some of them were synonymous. The last line in the synonymy of the Flora of Ethiopia and Eritrea deals with names of a variety with dark red to purplish stain on the trunk and underside of the leaves. It refers to a form collected outside Addis Ababa by a certain M. Maurel, former director of the school of l’Alliance Française in Addis Ababa, and was communicated to the Museum d’Histoire Naturelle in Paris by the French embassy secretary marquis de Scey-Montbéliard. The plant is described in a paper, Bananies d’Abyssinie a feuilles rouges, published in Bulletin du Museum National d’Histoire Naturelle, 2e Série, vol. 2: 688-690 (1931), by “M. D. Bois”, which must stand for Madame or Mademoiselle Désiré Bois, professor at the Jardin des Plantes, the botanical garden in Paris. She states that she had received this plant for cultivation in the botanical garden and named and described it as Musa ensete Gmel. var. montbeliardi Bois (in a footnote on p. 688). Georg Cufodontis reviewed between 1953 and 1972 the entire botanical literature on the Horn of Africa in a work called Enumeratio plantarum aethiopiae spermatophyta [Enumeration of Ethiopian Seed Plants], published as a supplement series to the journal Bulletin du Jardin Botanique de l’Etat, Bruxelles (for the later parts renamed as Bulletin du Jardin Botanique National de Belgique). When dealing with the genus Ensete (on p. 1593 in the final fascicle in Bulletin du Jardin Botanique National de Belgique 42(3), Supplement): 1579-1657, 1972), he accepted the status of the red-leaved enset-plants as a formal variety, but transferred it to the correct species name as Ensete ventricosum (Welw.) Cheesman var. montbeliardii (Bois) Cufod. The type of this variety is in the Flora of Ethiopia and Eritrea indicated as being a holotype at the Museum National d’Histoire Naturelle in Paris, but that was only guesswork, and, until today, no type material of var. montbeliardii has been

Ethiop. J. Biol. Sci., 17(Suppl.): 1–23, 2018 17 found. The plant was probably only cultivated in the garden, and no herbarium material made of it. Appendix 2: Global overview of the genus Ensete with full synonymy and distributional data. Unlike the synonymy in the Flora of Ethiopia and Eritrea, a full synonymy of Ensete ventricosum will at least include the synonyms below from a range of African countries. This has been done here in a complete review of all hitherto described species of Ensete. The list is a compilation of the information in Väre and Häkkinen (2011), Lebrun and Stork (2012) and WCSP (2018), supplemented with data from other sources where necessary. Invalid and illegitimate names are not included. Standard abbreviations have been used for the literature references. In many cases the type material is mounted on two or more sheets, due to the size of the plant, but in agreement with the International Code of Nomenclature for Plants, Algae and Fungi, one plant mounted on two sheets can be the type. The species of Ensete are here listed in agreement with the sequence in the cladogram of Liu, Kress and Li (2010), with the exception that E. lasiocarpa is placed between the African and Malagassy species and the Asian species, and that the little studied E. perrieri (not in the phylogeny) is placed at the end of the African species. Ensete Bruce ex Horaninow, Prodr. Monogr. Scitam: 40 (1862); - type species: Ensete edule Bruce ex. Horan., Prodr. Scitam: 40 (1862). Seven species in the tropical and warm temperate regions from West Africa to New Guinea. 1. Ensete ventricosum (Welw.) Cheesman, Kew Bull. 2(2): 101 (1948 [1947, publ. 12 Apr 1948]); Musa ventricosa Welw., Apontamentos Phytogeogr.: 587 (1859) - type: Angola, Pungo Andongo, (Rocky places near rivulets, 10° S lat.), 1857, Welwitsch 6447 (K, lectotype, designated by Baker and Simmonds, 1953, according to Väre and Häkkinen, 2011; BM, LISU isotypes). Musa ensete Gmel, Linn. Syst. Nat., ed. 13, amend. 2(2): 567 (1791); Ensete edule Horan., Prodr. Monog. Scitam.: 40 (1862) – type: Ethiopia, illustrations between p. 36 and 37 in Vol. 5, Select specimenes nat. hist., in Bruce: Travels (1790), lectotype, designated by Baker and Simmonds (1953), according to Väre and Häkkinen (2011).

18 Sebsebe Demissew and Ib Friis

Musa proboscidea Oliv., in Hooker's Icon. Pl. 18: t. 1777 (1888) [1887- 1888, publ. Oct 1888]; Ensete proboscideum (Oliv.) Cheesman, Kew Bull. 2(2): 102. (1948 [1947, publ. 12 Apr 1948]) - Type: Tanzania, Ukami hills, 100 miles inland to the west of the island of Zanzibar, 1885, J. Kirk 1777 (K, K000099716, lectotype, designated by Baker and Simmonds, 1953, according to Väre and Häkkinen, 2011). Musa buchananii Baker, Ann. Bot. (Oxford) 7: 207 (1893); Ensete buchananii (Baker) Cheesman, Kew Bull. 2(2): 102 (1948 [1947, publ. 12 Apr 1948]) – type: Malawi, Shire highlands, [1885], J. Buchanan 470 (K, K000099717, lectotype, designated by Baker and Simmonds, 1953, according to Väre and Häkkinen, 2011). Musa schweinfurthii K. Schum. & Warb. in K.Schum., Das Pflanzenreich IV, 45, Musac.: 14. (1900) [4 Oct 1900]; Ensete schweinfurthii (K. Schum. & Warb.) Cheesman, Kew Bull. 2(2): 103 (1948 [1947 publ. 12 Apr 1948]) – type: South Sudan, Niamniam, wild in Baginosa, 28.5.1870, Schweinfurth (2. Ser.), 130 (BM, BM000911547 and BM000911547, lectotype, designated by J.M Lock, 1993, according to Väre and Häkkinen, 2011). Musa arnoldiana De Wild., Bull. Soc. Etud. Col. Brux. 8: 339 (1901); Ensete arnoldianum (De Wild.) Cheesman, Kew Bull. 2(2): 103. (1948 [1947 publ. 12 Apr 1948]) - Type: Democratic Republic of Congo, Congo, Région de Dembo, 1901, J.Gillet 1850 (BR, BR880762 and BR880764, lectotype, designated by Baker and Simmonds, 1953, according to Väre and Häkkinen, 2011). Musa holstii K. Schum., Bot. Jahrb. Syst. 34(1): 121 (1904) [22 Mar 1904]; Ensete holstii (K. Schum.) Cheesman, Kew Bull. 2(2): 103 (1948 [1947 publ. 12 Apr 1948]) – Type: Tanzania, West Usambara, Sakara, 25.9.1902, A. Engler 2254 (B lectotype, designated by J.M. Lock, 1993, according to Väre and Häkkinen, 2011; BM, K, isotypes). Musa ulugurensis Warb. & Moritz, Tropenpflanzer 8: 116 (1904); Ensete ulugurense (Warb. & Moritz) Cheesman, Kew Bull. 2(2): 103. (1948 [1947 publ. 12 Apr 1948]) – type: an unnumbered plate with illustration of the plants at p. 117 (lectotype, designated by Väre and Häkkinen, 2011). Musa fecunda Stapf, J. Linn. Soc., Bot. 37: 528. 1906 [1904-1906 publ. 1906]; Ensete fecundum (Stapf) Cheesman, Kew Bull. 2(2): 103 (1948 [1947 publ. 12 Apr 1948]) – type: Uganda, Toro, Isunga, M.T. Dawe 521 (K, lectotype, K000099679, K000099680, designated by Baker and Simmonds, 1953, according to Väre and Häkkinen, 2011).

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Musa laurentii De Wild., Miss. Em. Laurent, vol.1: 371 (1907); Ensete laurentii (De Wild.) Cheesman, Kew Bull. 2(2): 103 (1948 [1947 publ. 12 Apr 1948]) - type: Democratic Republic of Congo, Stanleyville (Kisangani), 15.1.1904, E. & M. Laurent s.n. (BR, lectotype, BR000000880768, designated by Baker and Simmonds, 1953, according to Väre and Häkkinen, 2011). Musa bagshawii Rendle & Greves, J. Bot. 48: 169 (1910); Ensete bagshawei (Rendle & Greves) Cheesman, Kew Bull. 2(2): 103 (1948 [1947 publ. 12 Apr 1948]) - Type: Uganda, Foweira, Unyoro at 3500 ft., 25.4.1907, Bagshawe 1582 (BM, BM000911549, BM000911550, lectotype, designated by Baker and Simmonds, 1953, according to Väre and Häkkinen, 2011). Musa davyae Stapf, Bull. Misc. Inform. Kew 1913(3): 102. [1 May 1913]; Ensete davyae (Stapf) Cheesman, Kew Bulletin 2(2): 104 (1948 [1947 publ. 12 Apr 1948]) - Type: Mozambique, Amatongas forest, 27.XI.1907, W. H. Johnson s.n. (K, lectotype, designated by Väre and Häkkinen, 2011). Musa ruandensis De Wild., Bull. Jard. Bot. État Bruxelles 8: 111 (1923); Ensete ruandense (De Wild.) Cheesman, Kew Bull. 2(2): 104 (1948 [1947 publ. 12 Apr 1948]) - Type: Democratic Republic of Congo, Kisantu, 30.V.1923, J. Gillet s.n. (BR, BR000000880761, lectotype, designated by Baker and Simmonds, 1953, according to Väre and Häkkinen, 2011). Musa rubronervata De Wild., Bull. Jard. Bot. État Bruxelles 8: 112. (1923); Ensete rubronervatum (De Wild.) Cheesman, Kew Bull. 2(2): 104 (1948 [1947 publ. 12 Apr 1948]). - Type: Democratic Republic of Congo, Kisantu, 1923, J. Gillet s.n. (BR, BR000000880759, designated by Väre and Häkkinen, 2011). Musa ensete Gmel. var. montbeliardii Bois in Bull. Mus. Hist. Nat. Paris, 2. sér. 2: 688 (1931); Ensete ventricosum (Welw.) Cheesman var. montbeliardii (Bois.) Cufod. in Enum. Pl. Aeth. Sperm.: 1593 (1972) – type: Ethiopia, Shewa, near Addis Abeba, M. De Scey-Montebeliard s.n. (P, type material lost, no neotype selected). Musa kaguna Chiov. Raccolte Botaniche fatte dai Missionari della consolata nel Kenya: 119 (1935) – Type: Kenya, “Mt. Kenya e Aberdare, commune ovunque nel Kikuyu e nel Meru (Balbo)”. Musa kaguna is almost certainly a species of Ensete, and probably a synonym of E. ventricosum. The plant collection of “Missioini della Consolata” was at TOM, but the herbarium is being transferred to FT. The type material may probably be

20 Sebsebe Demissew and Ib Friis lost. Distributed in moist montane or submontane forests of Ethiopia (where widely cultivated, presumably outside its natural range), South Sudan, Uganda, Kenya, E. Democratic Republic of Congo, Rwanda, Burundi, Tanzania, Zambia, Malawi, Mozambique, Zimbabwe, Angola (Pungo Andongo), N part of South Africa (Lebrun and Stork, 2012; Anonymous, 2018). 2. E. homblei (Bequaert ex De Wild.) Cheesman, Kew Bull. 2(2): 103 (1948 [1947, publ. 12 Apr 1948]); Musa homblei Bequaert ex De Wild., in Ann. Mus. Colon. Marseille, 2. Sér., 10: 332 (1912) – type: Democratic Republic of Congo, Katanga, E’ville (Elisabethville), termitière (savane boisée), 5.1912, H. Homblé 671 (BR, lectotype, BR000000880858, BR000000880860, BR000000880859, designated by Baker & Simmonds, 1953, according to Väre and Häkkinen, 2011). At 1000-1200 m on termite mounds and rocky slopes in Brachystegia woodland in the extreme southern part of the Democratic Republic of Congo and in Zambia (Lebrun and Stork, 2012; Anonymous, 2018). According to Lock and Diniz (2010), this species could be an environmental modification of E. livingstonianum or an indraspecific taxon under that species; the question should be subject to closer studies. 3. E. livingstonianum (J. Kirk) Cheesman, Kew Bull. 2: 101 (1948 [1947, publ. 12 Apr 1948]); Musa livingstonianum J. Kirk, in J. Linn. Soc. 9: 128 (1867) – type: Malawi, “Manganja Hills”, J. Kirk s.n. (lectotype K, K000975139, designated by Goyder, 2014). Musa gilletii De Wild., Revue des Cultures Coloniales (Paris) 8: 102 (1901); Ensete gilletii (De Wild.) Cheesman, Kew Bull. 2(2): 103 (1948 [1947, publ. 12 Apr 1948]). — Type: Democratic Republic of Congo, Bas-Congo, Kisantu (à Luvituku), 1900, J. Gillet 700 (BR, BR0000008808654, BR0000008808639, BR0000008808622 and BR0000008808615, lectotype designated by Baker & Simmonds, 1953, according to Väre and Häkkinen, 2011). Musa religiosa J. Dyb., Revue Horticole 72: 262 (1900); Ensete religiosum (J.Dyb.) Cheesman, Kew Bull. 2(2): 103 (1948 [1947, publ. 12 Apr 1948]) —type: Democratic Republic of Congo, “Jardin colonial” s.n. (BR,

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BR000000880660, lectotype designated by Väre and Häkkinen, 2011). Musa elephantorum K. Schum. & Warb., Das Pflanzenreich IV,45, Musac.: 14 (1900); Ensete elephantorum (K. Schum. & Warb.) Cheesman in Kew Bull. 2(2): 102 (1948 [1947, publ. 12 Apr 1948]) – type: Cameroun, Yaunde Station, Berg Boukollo im Grasfelde an Abhängen, Zenker s.n. (B, all type material lost). Goyder (2014) has recorded it as a synonym of Ensete livingstoniana. Musa chevalieri Gagnep., Mém. Soc. Bot. France 2: 87 (1908); Ensete chevalieri (de Wild.) Cheesman, Kew Bull. 2: 103 (1948 [1947, publ. 12 Apr 1948]) — Type: [Central African Republic], Haut Oubangi, Fort Sibut, 6.XI.1902, A.J.B.Chevalier 6059 (P, lectotype, P00439288, designated by Väre and Häkkinen, 2011). From low altitudes to 1000-1900 m a.s.l at forest edges, in hilly grasslands and woodlands, on rocky escarpments, in old clearings and Pouteria altissima forest in Sierra Leone, Guinean Republic, Ivory Coast, S. Mali (?), Ghana, Benin, Togo, Nigeria, Cameroon, Central African Republic, Democratic Republic of Congo, Angola, Zambia, Malawi and Mozambique (Lebrun and Stork, 2012; WCSP, 2018; Anonymous, 2018). 4. E. perrieri (Claverie) Cheesman, Kew Bull. 2(2): 103 (1948 [1947, publ. 12 Apr 1948]); Musa perrieri Claverie, Comptes Rendus de l’Académie des Sciences de Paris 140: 1612 (1905). — type: Madagascar, Ouest, (Fianarantsoa Province Atsimo-Atsinanana Region, District of Vangaindrano), Ambongo, terrains calcaires, bois rocailleux (stony forest on calcareous ground), 2.1905, H. Perrier de la Bâthie 1796 (P, lectotype, P00109945, designated by Väre and Häkkinen, 2011). In Madagascar in habitats as listed for the type material. 5. E. lasiocarpa (Franch.) Cheesman, Kew Bull. 2(2): 102 (1948 [1947, publ. 12 Apr 1948]); Musa lasiocarpa Franch., J. de Botanique (Morot) 3: 329 (1889); (Franch.) H.W.Li, Acta Phytotax. Sinica 16: 57 (1978). — Type: Franchet (1889), J. de Botanique 3: fig. 1 (lectotype, designated by Häkkinen and Väre, 2008). Musella lasiocarpa (Franch.) H.W.Li var. rubribracteata Z.H. Li & H. Ma, in Novon 21(3): 351, f. 1 & 2. (2011) – type: China, Sichuan, Panzhihua City, near Upper Yangtze River, 15.5.2009, Z.H. Li & H. Ma 09SC66

22 Sebsebe Demissew and Ib Friis

(IFRD, holotype). Musella lasiocarpa var. rubribracteata is a synonym of E. lasiocarpa, according to WCSP (2018). The species occurs in China (S Guizhou, C and W Yunnan) and Vietnam, where it grows wild on rocky slopes or is cultivated in gardens; 1500–2500 m. a.s.l. (Delin and Kress, 2000, Anonymous, 2018). 6. E. glaucum (Roxb.) Cheesman, in Kew Bull. 2(2): 101 (1948 [1947, publ. 12 Apr 1948]). var. glaucum Musa glauca Roxb., Plants Coast Cormandel 3: 96 (1819). – type: Illustration, Fig. 300 in Plants of the Coast of Coromandel 3: fig. 300 (1819) (lectotype, designated by Argent, 1976). Musa agharkarii Chakravorti, Journ. Indian Bot. Soc. 27: 93 (1948); Ensete agharkarii (Chakravorti) D.K. Hore, B.D. Sharma & G. Pandry, Journal of Economic and Taxonomic Botany 16(2): 450 (1992) – type: Illustration in Indian Bot. Soc. 27: Pl. 1, fig 1-5, lectotype, designated by Väre and Häkkinen, 2011). The status of Musa/Ensete aghakarii as synonym of E. glaucum var. glaucum is accepted from Joe et al. (2016) and WCSP (2018). It is not recorded by Anonymous (2018). The species occurs in open places near forest margins and in grasslands, occasionally near small streams and on river banks, and in moist soil, occasionally in rocky ravines, but very often also cultivated, from near sea level to 2700 m a.s.l. in China (S and W Yunnan), Nepal, Bangladesh, north-eastern India, Myanmar, Indonesia, Taiwan, New Guinea, Philippines, Vietnam, Laos and Thailand (Delin and Kress 2000; Joe et al., 2016; Anonymous, 2018). var. wilsonii (Tutcher) Häkkinen, in Adansonia 3. Sér, 3: 199 (2011). Musa wilsonii Tutcher, in Gardeners’ Chronicle ser. 3, 32: 450 (1902); Ensete wilsonii (Tutcher) Cheesman, Kew Bull. 2(2): 103 (1948 [1947, publ. 12 Apr 1948]) — type: Tutcher, in Gardeners’ Chronicle ser. 3, 32: fig. 151 (1902) (lectotype, designated by Väre and Häkkinen, 2011). Ensete wilsonii is often considered a distinct species in the literature, but a variety of E. glaucum by Väre and Häkkinen (2011) and WCSP (2018). The variety grows as wild or cultivated in fertile soil in ravines, from near sea level to 2700 m a.s.l. in China, Yunnan (Delin and Kress, 2000).

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7. E. superbum (Roxb.) Cheesman, Kew Bull. 2(2): 100 (1948 [1947, publ. 12 Apr 1948]); Musa superba Roxb., Flora Indica 2: 489 (1824) – type: “East India”, Roxburgh s.n. (K, K000309030, lectotype, designated by Väre and Häkkinen, 2011). Ensete lecongkietii Luu, N.L. Vu & Q.D. Nguyen, Folia Malaysiana 13(2): 44 (2012) - type: Vietnam, Binh Thuan Province, Ham Thuan Nam District, Thuan Nam Township, Nhan Hill, 5.6.2012, Luu 872 (VNM, holotype). Ensete lecongkietii is described from a plant collected near a village in Vietnam; although accepted by WCSP (2018) and Anonymous (2018), it has been reduced to synonym by Joe et al. (2016). They argue that the type specimen was found close to human habitation in Vietnam, and that the distinction of it is based mainly on differences in size and number of anthers in male flowers compared with those of E. superbum, thus it only differs from typical E. superbum in being smaller in a number of parts, and they consider it a cultivated form of E. superbum. E. superbum is native to India, but cultivated in Myanmar, Thailand and Vietnam (Anonymous, 2018; WCSP, 2018). It occurs mostly in rocky areas or in moist soils, and sometimes in rock crevices and steep rocky cliffs. It takes one to more than six years to flower (Joe et al., 2016). Name probably belonging to the genus Ensete, but of uncertain identity: Musa bacoba Rottb., Descript. Pl. Rarior.: 28 (1776) - type not traced.

Ethiop. J. Biol. Sci. 17(Suppl.): 25–36, 2018 © The Biological Society of Ethiopia, 2018 ISSN: 1819-8678 TRENDS AND GAPS IN ENSET (ENSETE VENTRICOSUM (WELW.) CHEESMAN RESEARCH

Masresha Fetene1* and Getahun Yemata2

ABSTRACT: Enset is a multipurpose crop that supports the livelihood of 20 million people. Enset starch is also used for paper, textile, adhesive industries and pharmaceuticals in tablet formulation as a binder and disintegrant. However research and extension on the crop was given attention recently. It was only in the 1970s that enset research, begun focusing on enset clone collection, evaluation for food, fiber, and maintenance of germplasm. This was followed by agronomic studies on the effect of traditional management methods such as transplanting, spacing and leaf pruning on dry matter production, food production and harvest indices. Some ecophysiological studies revealed that drought tolerance in enset was attributed to osmotic adjustment and improved water extraction through altered biomass partitioning. Currently, serious attention is given to the threat of enset bacterial wilt to enset cultivation. Consequently, research activities on the use of medicinal plant extracts and other bio-control agents and methods against bacterial wilt pathogens, and selection of disease resistance varieties have been initiated through coordinated multidisciplinary research to alleviate the problem of enset bacterial wilt. Despite the relatively better research attention given to enset in the past two decades, as compared to the previous ones, there are still several research gaps that need to be addressed. It is recommended that establishing a national database on enset research with periodic bibliographic publication; creating a clone collection centre; developing a prioritized enset research agenda and creating a National Enset Research Institute is of paramount importance. This will ensure the sustainable production of the crop for food security, income generation, agro- industry development and environment sustainability.

Key words/phrases: Agronomy, Ecophysiology, Enset bacterial wilt, Enset diversity, Osmotic adjustment.

INTRODUCTION Enset is a multipurpose traditional crop widely cultivated in south and southwestern Ethiopia. The crop is embedded into the tradition of the people. It feeds approximately 20 million people in the country (Temesgen Magule et al., 2014). The crop has a number of desirable qualities which makes it superior to many other crops as a reliable crop in a population

1 Department of Plant Biology and Biodiversity Management, College of Natural and Computational Sciences, Addis Ababa University, P.O. Box 3434, Addis Ababa, Ethiopia. E-mail: [email protected] 2 Department of Biology, Bahir Dar University, Bahir Dar, Ethiopia *Author to whom all correspondence should be addressed 26 Masresha Fetene and Getahun Yemata facing food insecurity. For instance, enset gives the highest yield per unit area and thus supports the densely populated areas in the south of the country (Admasu Tsegaye and Struik, 2001). Enset foods can be stored for long periods. The crop performs better than other crops even without the use of costly agricultural inputs. Furthermore, although the crop has long maturity time, it can be harvested before it attains maturity, allowing enset growers to surmount periods of food shortage (Admasu Tsegaye, 2002; Dereje Fekadu, 2009). Enset also grows in a wide range of altitudes extending from about 1200 to 3100 meters above sea level which means that farmers can expand the cultivation of the crop in all parts of the country including areas not suitable for cereal cultivation. Despite all these qualities, the crop received very little research attention in the past as compared to cereals. Nevertheless, significant advances have been made in recent times that are encouraging. The objective of this contribution is to review past and current research activities in enset agriculture and to explore areas that require immediate research attention. PAST AND CURRENT RESEARCH TRENDS Enset research started in the 1970s during which time clone collection, evaluation of the value of the crop for food and fiber, its agronomic traits and maintenance of germplasm were the main focuses (Seifu Gebremariam, 1996). During this period, 163 clones were collected, of which 103 and 60 were established at Holetta and Debre Zeit (Bishoftu), respectively. Clones with long pseudostem and large corms were found to be appropriate for fiber and food, respectively (Seifu Gebremariam, 1996). In 1976, enset clone collections were transferred to Wolaita Sodo with the establishment of Areka Enset Research Centre, in 1986 with the objective of collection, evaluation and germplasm maintenance research. However, this site was closed in 1981/82 (Terefe Belehu, 1996). Since then, research has been extended to address the other aspects of the crop with outstanding findings. Several researches have been conducted about the influence of traditional crop management methods on dry matter and food production, and Kocho yield under different crop establishment methods were undertaken on limited enset clones (Admasu Tsegaye and Struik, 2001). Furthermore, Admasu Tsegaye (2002) made studies on characterization and diversity of enset, harvest indices, harvest and postharvest losses over the years. Admasu Tsegaye (2007) also showed that repetitive transplanting decreases total plant dry matter yield per unit area. This practice increases dry matter partitioning to harvestable parts such as pseudostem and corm. Unlike Ethiop. J. Biol. Sci., 17(Suppl.): 25–36, 2018 27 transplanting, leaf pruning had insignificant effect on total dry matter production and partitioning. Investigation into the nutrient status (Asnaketch Woldetensaye, 1997) of enset farming systems and nutrient balance therein (Tilahun Amede and Mulugeta Diro, 2005; Amare Haileselassie et al., 2006) showed that enset fields have a higher organic matter, nitrogen and phosphorus levels with significantly higher positive balances than cereal systems such as teff because of the possible use of enset litter as source of organic matter and mulch (Asnaketch Woldetensaye, 1997). These works implied that enset productivity can be sustained by implementing management practices that reduce nutrient loss from the system such as piling the manure and other household refuse between enset plants in an open air and applying at the surface. Cultivation of clones with higher nutrient use efficiency has also been recommended (Ferew Kebede, 2012). Cultivation of enset has a long history with a strong cultural entrenchment with people of the different ethnic groups especially in south Ethiopia. An Ari ritual specialist explained the cultural entrenchment as: “We and enset have a long history of relatedness. We rely on it and it relies on us for survival. This means we cannot live without it and it cannot live without us either; we are created to support each other” (Gebre Yntiso, 1996). Each ethnic group has its own enset clone selection criteria, management practice and use preferences (Zippel and Ludder, 2005). It is also linked with a gender issue whereby men propagate plant and replant and women solely do harvesting by forming a small working group of friends and close relatives. Under the circumstances, efforts have been made to improve enset processing tools and minimize the labour burden of women. This shows that enset also strengthens the social interaction (Sandford and Helen Kassa, 1996; Spring, 1996). Moreover, hundreds of enset clones have been documented and characterized on the basis of phenotypic and molecular techniques (Endale Tabogie, 1997; Almaz Negash et al., 2002). According to Endale Tabogie (1997), enset clones have been grouped into 29 classes based on resemblance in colouration pattern (pseudostem, petiole and midrib) or presence of slight name variation suggesting that pseudostem, midrib, petiole and midrib are important parts that need to be exploited for diversity studies. A baseline survey by SARI (2013) enumerated a total of 440 cultivar names in eight enset growing administrative zones in Ethiopia. The number of cultivars in each zone was 75 (Dawro), 26 (Gedeo), 63 (Gurage), 51 (Hadiya), 66 (Kembata-Tembaro), 62 (Sidama), 69 (Silte) and 28 (Wolaita). However, this number was reduced to 312 after known 28 Masresha Fetene and Getahun Yemata synonyms were replaced with distinct names. Zerihun Yemataw et al. (2014) reported a total of 278 clones with distinct names from seven enset growing zones. Hadiya was the richest zone with a total of 59 clones followed by Kembata (43), Dawro (42), Wolaita (39), Gamo Gofa (34), Gurage (31) and Sidama (30). In a previous study, Admasu Tsegaye (2002) described 146 different enset clones from Sidama, Wolaita and Hadiya zones. Similarly, Almaz Negash (2001) recorded 146 different enset clones from four zones (65 from Kefa-Sheka, 30 clones from Sidama, 45 from Hadiya and 6 from Wolaita). In all the studies, duplication of names was reported in that the same enset clone was given different names in different areas and different enset clones were given the same name at different localities. Despite the large variation in agro-ecological conditions among enset growing areas, amplified fragment length polymorphism (AFLPs) studies revealed that only 4.8% of the total genetic variation was found between regions and 95.2% within regions or populations (Almaz Negash et al., 2002). This may be explained by regular long distance exchange of clones and the existence of substantial levels of phenotypic plasticity in enset due to changing weather and soil conditions (Almaz Negash et al., 2002; Zippel and Ludder, 2005). Genet Birmeta et al. (2004) studied 111 enset clones from nine enset growing areas of Ethiopia using Random Amplified Polymorphic DNA (RAPD) molecular methods, and suggested that the current cultivated enset clones had been introduced for domestication from a limited number of wild progenitors. They showed that the genetic diversity in cultivated enset in a particular area appeared to be related to the extent of enset cultivation, the culture and distribution pattern of the different ethnic groups than geographical distance. However, subsequent gene flow between wild and cultivated enset may have been inhibited by differences in modes of propagation and harvesting time. In cultivated enset, genetic diversity within populations was high (Dagmawit Chombe and Endashaw Bekele, 2011). Enset has a genome size of approximately 547 megabases, similar to the 523-megabase genome of the closely related banana (Musa acuminata). Additionally, enset contains genes that are absent in banana. These include reverse transcriptases, virus-like sequences and a homolog of the RPP8-like resistance gene indicating the large gene pool in the species that could be utilized for improvement of the crop (Genet Birmeta et al., 2004; Harrison et al., 2014). Although enset reproduces predominantly by vegetative Ethiop. J. Biol. Sci., 17(Suppl.): 25–36, 2018 29 means, several investigations were carried out to develop alternative propagation techniques using modern biotechnological approaches (Tilahun Zeweldu and Ladders, 1998; Mulugeta Diro, 2003). Currently, protocols are in place for in vitro regeneration, micro-propagation (Almaz Negash et al., 2000) and in vitro conservation of enset under slow growth conditions (Almaz Negash et al., 2001). The micro-propagation of enset shoot tip culture rapidly produces large numbers of clonal plantlets that are free from pathogens (Almaz Negash, 2001). Tissue culture is also used to propagate new genotypes and/or specific pathogen-tolerant clones to deliver genes carrying desirable traits from another species to enset so as to develop tolerance in enset to different environmental factors including enset bacterial wilt. In another development, enset growth, biomass accumulation and physiology have shown temporal variations which may be explained by the seasonal dynamics in precipitation, temperature and radiation. In relation to precipitation, drought stress induces accumulation of solutes (Solomon Zewdie et al., 2008) and alteration of biomass partitioning whereby more photosynthate is partitioned to belowground parts. These are adaptive responses to cope with the prevailing stress conditions. Moreover, Admasu Tsegaye and Struik (2003) reported yield differences between enset clones that were attributed to radiation use efficiency. Several research activities were conducted on the nutritive value of enset products. Accordingly, the chemical composition of enset dry matter as whole plant was 90.87% organic matter and 9.13% ash. The organic matter was composed of 5.98% crude protein, 0.84% crude fat, 9.48% crude fibre and 74.57% carbohydrates (Mohammed et al., 2013). The unprocessed corm of enset was found to be rich in calcium (Ca), magnesium (Mg), potassium (K), zinc (Zn), and iron (Fe) (Ayalew Debebe et al., 2012; Sirawdink Fikreyesus et al., 2013). Processed forms such as Kocho and Bulla were rich in calcium (Ca) and zinc (Zn) compared to other similar food stuffs and contained comparable concentration of copper (Cu), iron (Fe) and manganese (Mn). These products were free from heavy metal contaminants such as cadmium (Cd) and lead (Pb) (Minaleshewa Atlabachew, 2007). In addition, Amicho (boiled corm) had higher total phenolics content next to teff and corn (Sirawdink Fikreyesus et al., 2013). Moreover, Yewelsew Abebe et al. (2006) reported the presence of histidine (2.06), isoleucine (4.12), leucine (7.56), lysine (5.50), methionine+ (3.44), phenylalanine+ (6.78), threonine 30 Masresha Fetene and Getahun Yemata

(2.75), tryptophan (2.75) and valine (5.50) g/100 g of protein. Enset food products are generally poor in their protein content and thus enset dishes are always supplemented with animal products (Mohammed et al., 2013). Studies on genetic engineering to increase the protein content of enset to add value to the crop was minimal. Industrially, enset starch is used for various applications. Several studies reveal that enset starch has amylose content with granule size, x-ray diffraction pattern and gelatinization temperature comparable to potato starch, which is commonly used in pharmaceutical applications (Abraham Wondimu et al., 2014). Tsige Gebre-Mariam and Nikolayev (1993) also reported that enset starch can be used both as a tablet binder and disintegrant possessing a better binding ability and less disintegrating power than potato starch. It is also used as gelling agent. The cross-linked and acetylated form of enset starch shows its potential use as a novel drug delivery system (Abraham Wondimu et al., 2014). Furthermore, the squeezed and dehydrated product of enset (Bulla) is used as a gelling agent substituting agar for in vitro propagation. According to Biruk Ayenew et al. (2012), dried Bulla could be used as a gelling agent to produce an equivalent number of shoots, roots, leaves, shoot height and associated fresh weight of pineapple plantlets compared to the use of agar as medium. Of all environmental factors, enset bacterial wilt (EBW) caused by Xanthomonas campestris pv. musacearum (Xcm) (Dagnachew Yirgou and Bradbury, 1968; 1974), is the most important constraint to enset cultivation followed by drought (Solomon Zewdie et al., 2008). The pathogen also affects banana. Once established, the disease is difficult to control owing to the lack of an effective chemical or other curative treatments. Currently, a phytosanitary approach of the destruction of diseased plants has been suggested as the only option to control the disease (Biruma et al., 2007). The most attractive strategy for bacterial disease control in crops is to improve their natural defense mechanisms against a pathogen (Biruma et al., 2007). Related to this, research results have shown that induction of resistance can reduce disease incidence by 20-85% (Walters et al., 2013). In banana, researchers have been successful in producing bacterial wilt resistant banana varieties using transgenes encoding for plant ferredoxin- like protein (pflp) (Namukwaya et al., 2012) and hypersensitive response assisting protein (hrap) (Tripathi et al., 2010) isolated from sweet pepper (Capsicum annum). These are novel plant proteins that can intensify pathogen mediated hypersensitive response (Tripathi et al., 2010; Namukwaya et al., 2012). Ethiop. J. Biol. Sci., 17(Suppl.): 25–36, 2018 31

Although there had been early efforts to find alternative methods of controlling the bacterial wilt of enset, most of them were focused on characterization of the virulence of the pathogen and screening for enset clone resistance against Xcm (Kidist Bobosha, 2003; Gizachew Wolde- Michael et al., 2008; Tariku Hunduma et al., 2015; Mekuria Wolde et al., 2016). These researchers identified several resistant and susceptible enset clones to Xcm in different areas. Moreover, some studies also showed the antibacterial activity of medicinal plant extracts against Xcm (Kidist Bobosha, 2003; Daniel Kasa and Getaneh Woldeab, 2015; Getahun Yemata, 2016) and some promising in vitro effect on the pathogen (Getahun Yemata and Masresha Fetene, 2016). In enset, inducing plants of a susceptible clone with the crude leaf extract of a medicinal plant reduced disease incidence by 33% showing the prospect of the technique to control the disease. Induction of resistance was inferred from the higher activity of phenylalanine ammonia lyase, peroxidase, polyphenol oxidase and increased concentration of total phenolics in extract induced enset plant (Getahun Yemata and Masresha Fetene, 2016). RESEARCH GAPS Although enormous research efforts have been exerted on different aspects of enset, a lot remains to be done to maintain its sustainability. Despite the large variation in agro-ecological conditions among enset growing areas, molecular studies revealed that only 4.8% of the total genetic variation was found between zones and 95.2% within zones or populations (Almaz Negash, 2001; Almaz Negash et al., 2002). Thus, the cultural, social and economic basis of this variation, as well as advantages and disadvantages of the different traditional practices of each ethnic group need to be investigated (Admasu Tsegaye, 2002). To that end, research should be conducted on the selection criteria, management practices and use preferences of enset by different ethnic groups in order to conserve enset diversity for sustainable utilization of the crop. It was found out that the net rate of manure mineralization was rapid at the initial period of incubation, application of manure close to transplanting and immediate incorporation into the soil was highly recommended (Ferew Kebede, 2012). Since the rate of mineralization depends on climate, soil and the enset clone, studies should be undertaken in specific areas. There is also a dearth of information on the nutrient use efficiency of enset clones that require compulsory screening studies (Ferew Kebede, 2012). Furthermore, enset clones showed variations in their growth and yield performance under 32 Masresha Fetene and Getahun Yemata different environmental conditions. Consequently, there is need for studies on growth requirements and yield determining factors of the clones under different agro-ecologies to single out promising clones (Solomon Zewdie et al., 2008). Drought tolerance in enset has been reported to be due to osmotic adjustment and improved water extraction through altered biomass partitioning. However, due to the high enset clonal diversity, many more screening studies are required to search for more physiological traits of the clones that confer their tolerance to low moisture stress and water use efficiency. Moreover, studies on the interactive effects of multiple environmental factors on the growth and yield of enset, and intercropping with diverse crop species as well as landrace mixtures are all the more important in order to advance the production system and increase productivity per unit area (Admasu Tsegaye, 2002; Solomon Zewdie et al., 2008). In spite of the achievements in micropropagation, in vitro regeneration and in vitro conservation of enset (Almaz Negash, 2001), many more studies should be conducted on optimization of the protocol and hardening of the plantlets under glasshouse and field condition (Almaz Negash, 2001). With respect to the industrial application of enset products, there have been good beginnings to see the potential use of enset starch in tablet formulation as a binder and disintegrant (Tsige Gebre-Mariam and Nikolayev, 1993; Abraham Wondimu et al., 2014). However, more remains to be done to exploit the huge starch (60%) content of the crop and the strong enset fiber for a variety of purposes. Several trials have been made by different research groups to improve labour intensive and unhygienic enset processing tools. Not much success has been achieved in this respect as women still use traditional processing tools. The problem might be lack of awareness among enset farmers about the few available tools, low accessibility of the improved tools and inadequate research on the subject. Therefore, researches should be conducted that are geared towards producing affordable and easy to manipulate tools with the active involvement of women. Currently, the most critical problem in enset cultivation is enset bacterial wilt. Thus, organized researches need to be carried out on screening of medicinal plant extracts, evaluation of application methods and integrated management strategies. Moreover, the role of other biocontrol agents such as arbuscular mycorrhizal and Trichodermal fungi should also be evaluated. Ethiop. J. Biol. Sci., 17(Suppl.): 25–36, 2018 33

Researchers have been successful in producing bacterial wilt resistant banana varieties using transgenes. Since the pathogen is the same, genetic engineering studies to develop enset clones resistant to Xcm should be conducted at a large scale. Despite the relatively better research attention given to enset in the past two decades, as compared to the previous ones, there are still several research gaps that need to be addressed. It is recommended that establishing a national database on enset research with periodic bibliographic publication; creating a clone collection centre; developing a prioritized Enset research agenda and creating a National Enset Research Institute is an urgent requirement. This will ensure the contribution of enset production to food security, income generation, agro-industry development and environment sustainability. REFERENCES Abraham Wondimu, Fantahun Molla, Dinda, S.C., Naod Gebre-Samuel and Ebisa Tadese (2014). Literature review on enset starch: Physico-chemical properties and pharmaceutical applications. J. Drug Deliv. Ther. 4(3): 1–6. Admasu Tsegaye (2002). On Indigenous Production, Genetic Diversity and Crop Ecology of Enset (Ensete ventricosum (Welw.) Cheesman). Ph.D. Thesis, Wageningen University, Wageningen. Admasu Tsegaye (2007). Effects of repetitive transplanting and leaf pruning on growth and dry matter partitioning of enset (Ensete ventricosum (Welw.) Cheesman). J. Agron. 6: 45–52. Admasu Tsegaye and Struik, P.C. (2001). Enset (Ensete ventricosum Welw. Cheesman) ‘kocho’ yield under different crop establishment methods as compared to yields of other carbohydrate-rich food crops. Neth. J. Agri. Sci. 49: 81–94. Admasu Tsegaye and Struik, P.C. (2003). Growth, radiation use efficiency and yield potential of enset (Ensete ventricosum (Welw.) Cheesman) at different sites in Southern Ethiopia. Ann. Appl. Biol. 142: 71–81. Almaz Negash (2001). Diversity and Conservation of Enset (Ensete ventricosum Welw. Cheesman) and its Relation to Household Food and Livelihood Security in South-western Ethiopia. Ph.D. Thesis, Wageningen University, Wageningen. Almaz Negash, Admasu Tsegaye, Van Treuren, R. and Visser, B. (2002). AFLP analysis of enset clonal diversity in south and southwestern Ethiopia for conservation. Crop Sci. 42: 1105–1111. Almaz Negash, Puite, K., Schaart, J., Visser, B. and Krens, F. (2000). In vitro regeneration and micro-propagation of enset from Southwestern Ethiopia. Plant Cell Tiss. Org. 62: 153–158. Almaz Negash, Schaart, J., Krens, F. and Visser, B. (2001). In vitro conservation of enset (Ensete ventricosum Welw. Cheesman) under slow growth conditions. Plant Cell Tiss. Org. 66(2): 109–113. Amare Haileselassie, Priess, J.A, Veldkamp, E. and Lesschen, P. (2006). Small holders’ soil fertility management in the central highlands of Ethiopia: Implications for 34 Masresha Fetene and Getahun Yemata

nutrient stocks, balances and sustainability of agroecosystems. Nutr. Cycl. Agroecosys. 75: 135–146. Asnaketch Woldetensaye (1997). The Ecology and Production of Ensete ventricosum Welw.) Cheesman in Ethiopia. Doctoral Thesis, Swedish University of Agricultural Sciences, Uppsala. Ayalew Debebe, Chandravanshi, B.S. and Taddese Wondimu (2012). Metallic nutrients in enset (Ensete ventricosum) corm cultivated in Wolliso and Wolkite towns in Ethiopia. SINET: Ethiop. J. Sci. 35(2): 71–80. Biruk Ayenew, Ayelign Mengesha, Tewodros Tadesse and Elias Gebre-Mariam (2012). Ensete ventricosum (Welw.) Cheesman: A cheap and alternative gelling agent for pineapple (Ananas comosus var. smooth cayenne) in vitro propagation. J. Microbiol. Biotechnol. Food Sci. 2(2): 640–652. Biruma, M., Pillay, M., Tripathi, L., Blomme, G., Abele, S., Mwangi, M., Bandyopadhyay, R., Muchunguzi, P., Kassim, S., Nyine, M., Turyagyenda, L. and Eden-Green, S. (2007). Banana Xanthomonas wilt: of the disease, management strategies and future research directions. Afr. J. Biotechnol. 6(8): 953–962. Dagmawit Chombe and Endashaw Bekele (2011). Analysis of genetic diversity among cultivated enset (Ensete ventricosum) populations from Essera and Kefficho, southwestern part of Ethiopia using inter simple sequence repeats (ISSRs) marker. Afr. J. Biotechnol. 10(70): 697–709. Dagnachew Yirgou and Bradbury, J.F. (1968). Bacterial wilt of enset (Ensete ventricosum) incited by Xanthomonas musacearum sp. n. Phytopathology. 58: 111–112. Dagnachew Yirgou and Bradbury, J.F. (1974). A note on wilt of banana caused by the enset wilt organism, Xanthomonas musacearum. E. Afr. Agr. Forestry J. 40: 111–114. Daniel Kasa and Getaneh Woldeab (2015). Evaluation of different botanical plant extracts and other material against enset bacterial wilt (Xanthomonas campestris pv musacearum) disease in Oromia Regional State, Ethiopia. ARPN J. Sci. Technol. 5(2): 68–73. Dereje Fekadu (2009). Characterizing farming practices from three regions of Ethiopia on which enset (Ensete ventricosum) is widely profited as a multipurpose crop plant. Ethiopian Institute of Agricultural Research, Holetta Research Center, Holetta. Endale Tabogie (1997). Morphological Characterization of Enset (Ensete ventricosum (Welw.) Cheesman) Clones and the Association of Yield with Different Traits. M.Sc. Thesis, Alemaya University of Agriculture, Alemaya. Ferew Kebede (2012). Management Strategies for Improving Manure Nutrient Use Efficiency and Productivity of Subsistent Farmers in Enset-based Farming Systems of Southern Ethiopia. Ph.D. Dissertation, Addis Ababa University, Addis Ababa. Gebre Yntiso (1996). Economic and socio-cultural significance of enset among the Ari of southwestern Ethiopia. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 119–121 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings of the International Workshop on enset (1993), Institute of Agricultural Research, Addis Ababa. Genet Birmeta, Nybomn, H. and Endashaw Bekele (2004). Distinction between wild and cultivated enset (Ensete ventricosum) gene pools in Ethiopia using RAPD markers. Hereditas 140: 139–148. Getahun Yemata (2016). Growth and Physiological and Biochemical Responses of Enset (Ensete ventricosum (Welw.) Cheesman) Clones Infected with Bacterial Ethiop. J. Biol. Sci., 17(Suppl.): 25–36, 2018 35

Wilt. Ph.D. Thesis, Addis Ababa University, Addis Ababa. Getahun Yemata and Masresha Fetene (2016). Induction of systemic resistance in Ensete ventricosum clones by the leaf extract of Agarista salicifolia against Xanthomonas campestris pv. musacearum. J. Plant Pathol. 98(3): 51–62. Gizachew Wolde-Michael, Kidist Bobosha, Blomme, G., Temesgen Addis, Tilahun Mengesha and Simeamelak Mekonnen (2008). Evaluation of enset clones against enset bacterial wilt. Afr. Crop Sci. J. 16(1): 89–95. Harrison, J., Moore, K.A., Paszkiewicz, K., Jones, T., Grant, M.R., Daniel Ambachew, Muzemil, S. and Studholme, D.J. (2014). A draft genome sequence for Ensete ventricosum, the drought-tolerant “Tree against Hunger” Agron. 4: 13–33. Kidist Bobosha (2003). Characterization of Xanthomonas campestris pv. musacearum Isolates: Causal Agent of Enset Bacterial Wilt Disease. M.Sc. Thesis, Addis Ababa University, Addis Ababa. Mekuria Wolde, Amare Ayalew, Alemayehu Chala (2016). Evaluation of enset clones for their reaction to bacterial wilt of enset (Xanthomonas campestris pv. musacearum) in Gurage zone, Southern Ethiopia. Jordan J. Biol. Sci. 9(2): 109–115. Minaleshewa Atlabachew (2007). Studies on Commercially Available Enset (Ensete ventricosum (Welw.) Cheesman) Food Products (Kocho and Bulla) for Major, Minor and Trace Elements. M.Sc. Thesis, Addis Ababa University, Addis Ababa. Mohammed, B., Gabel, M. and Karlsson, L.M. (2013). Nutritive values of the drought tolerant food and fodder crop enset. Afr. J. Agr. Res. 8(20): 26–33. Mulugeta Diro (2003). In vitro Propagation of Enset (Ensete ventricosum (Welw.) Cheesman). Ph.D. Thesis, University of Natal, Republic of South Africa. Namukwaya, B., Tripathi, L., Tripathi, J.N., Arinaitwe, G., Mukasa, S.B. and Tushemereirwe, W.K. (2012). Transgenic banana expressing Pflp gene confers enhanced resistance to Xanthomonas wilt disease. Transgenic Res. 21: 855–865. Sandford, J. and Helen Kassa (1996). The effect of gender on resource contribution, decision making and influence: A comparison between enset, tef and maize. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 165–171 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings from the International Workshop on Enset held in Addis Ababa, Ethiopia, 18-20 December, 1993, Institute of Agricultural Research, Addis Ababa. SARI (2013). Integrated management of bacterial wilt of enset (Ensete ventricosum (Welw.) Cheesman) caused by Xanthomonas campestris pv. musacearum in Ethiopia. The McKnight Foundation Collaborative Crop Research Project, November 2013 to October 2014, Annual progress report. Seifu Gebremariam (1996). Enset research in Ethiopia: 1976-1984. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 204–220 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings from the International Workshop on Enset held in Addis Ababa, Ethiopia, 18-20 December, 1993, Institute of Agricultural Research, Addis Ababa. Sirawdink Fikreyesus, Rupasinghe, H.P.V. and Tess Astatkie (2013). Antioxidant capacity, total phenolics and nutritional content in selected Ethiopian staple food ingredients. Int. J. Food. Sci. Nutr. 64(8): 915–920. Spring, A. (1996). Gender issues and farming systems research and extension in enset agriculture in Ethiopia. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 172–187 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, 36 Masresha Fetene and Getahun Yemata

eds.). Proceedings from the International Workshop on Enset held in Addis Ababa, Ethiopia, 18-20 December, 1993, Institute of Agricultural Research, Addis Ababa. Solomon Zewdie, Olsson, M. and Masresha Fetene (2008). Effect of drought/irrigation on proximate composition and carbohydrate content of two enset (Ensete ventricosum (Welw.) Cheesman) clones. SINET: Ethiop. J. Sci. 31(2): 81–88. Tariku Hunduma, Kassahun Sadessa, Endale Hilu and Mengistu Oli (2015). Evaluation of enset clones resistance against enset bacterial wilt disease (Xanthomonas campestris pv. musacearum). J Vet. Sci. Technol 6: 232. doi:10.4172/2157- 7579.1000232 Temesgen Magule, Bizuayehu Tesfaye, Catellani, M. and Enrico P.M. (2014). Indigenous knowledge, use and on-farm management of enset (Ensete ventricosum (Welw.) Cheesman) diversity in Wolaita, Southern Ethiopia. J. Ethnobiol. Ethnomed. 10:41 doi: 10.1186/1746-4269-10-41. Terefe Belehu (1996). Enset research in Ethiopia: 1985-1993. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 221–227 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings from the International Workshop on enset held in Addis Ababa, Ethiopia, 18-20 December, 1993, Institute of Agricultural Research, Addis Ababa. Tilahun Amede and Mulugeta Diro (2005). Optimizing soil fertility gradients in the enset systems of the Ethiopian highlands: Trade-offs and local innovations. In: Improving Human Welfare and Environmental Conservation by Empowering Farmers to Combat Soil Fertility Degradation, pp. 1–10 (Bationo et al., eds.). African Highlands Initiative, Working Papers 15. Tilahun Zeweldu and Ladders, P. (1998). Preliminary tissue culture investigation in Ensete (Ensete spp.) Angew. Bot. 72: 25–27. Tripathi, L., Mwaka, H., Tripathi, J.N. and Tushemereirwe, W.K. (2010). Expression of sweet pepper Hrap gene in banana enhances resistance to Xanthomonas campestris pv. musacearum. Mol. Plant Pathol. 11(6): 721–731. Tsige Gebre-Mariam and Nikolayev, A.S. (1993). Evaluation of starch obtained from Ensete ventricosum as a binder and disintegrant for compressed tablets. J. Pharm. Pharmacol. 45: 317–320. Walters, D.R., Ratsep, J. and Havis, N.D. (2013). Controlling crop diseases using induced resistance: Challenges for the future. J. Exp. Bot. doi:10.1093/jxb/ert026. Accessed on May 14, 2015. Yewelsew Abebe, Stoecker, B.J., Hinds, M.J. and Gates, G.E. (2006). Nutritive value and sensory acceptability of corn- and kocho-based foods supplemented with legumes for infant feeding in southern Ethiopia. Afr. J. Food Agric. Nutr. Dev. 6(1): www.ajfand.net Zerihun Yemataw, Mohamed, H., Mulugeta Diro, Temesgen Addis and Blomme, G. (2014). Ethnic-based diversity and distribution of enset (Ensete ventricosum) clones in southern Ethiopia. J. Ecol. Nat. Environ. 6(7): 244–251. Zippel, K. and Ludder, P. (2005). The global food and product chain: Dynamics, innovations, conflicts, strategies” Ensete ventricosum in Ethiopia: The need to grow more than one landrace. Deutscher Tropentag, October 11-13, 2005, Hohenheim. Ethiop. J. Biol. Sci. 17(Suppl.): 37–49, 2018 © The Biological Society of Ethiopia, 2018 ISSN: 1819-8678 THE CENTRE OF ORIGIN AND DOMESTICATION OF ENSETE VENTRICOSUM (WELW.) CHEESMAN AND ITS PHYLOGENETIC RELATIONSHIP TO SOME MUSA SPECIES

Endashaw Bekele1

ABSTRACT: Ensete ventricosum is one of the species in the genus Ensete whose species composition is not yet known. This paper attempts to trace the origin of domesticated enset and early food production in Ethiopia, historical evidence of its distributions, botanical and genetic diversity of cultivated and wild enset forms. Based on ecological distribution of wild enset in Ethiopia, the highly dissected terrain of lower altitudes of South and Southwestern drier zones might be the initial sites of enset domestication. The complexity of enset culture and its use value and in South and Southwest of Ethiopia indicate longer period of enset cultivation. The existence of an early and dynamic root and tuber crop-based agriculture before seed and fruit-based crop system also support the early domestication of enset in South and South West of Ethiopia. A molecular genetic data from RAPD, chloroplast and ITS DNA sequence suggest that different clones of cultivated enset seem to have originated from different clones of wild enset suggesting the existence of several microcentres of domestication in the region. The wild enset forms and the cultivated forms seem to introgress and escape to the wild and domesticated sites of enset, respectively. RAPD and ITS molecular data as well as complete sequences of transcribed spacers and introns from trnT terF region of chloroplast DNA from thirteen species of Musa and three species of Ensete, including the cultivated and wild species of Ensete ventricosum indicated that and Mussa beccarii represent ancestral forms of Ensete and Musa, respectively. The data also showed that E. ventricosum cannot be reduced to E. glaucum, nor can E. gilletti be reduced to E. ventricosum, as some authorities have suggested. Ensete gilletti or a species very close to it appears to be the ancestral species of E. ventricosum.

Key words/phrases: Centre of origin and domestication, Ensete ventricosum, Molecular data, Musa species.

INTRODUCTION Ensete ventricosum is an important commodity and a staple diet for a large section of Ethiopian community. The progress of research on cultivated enset in Ethiopia has been well documented (Taye Bezuneh and Asrat Feleke, 1966; Taye Bezuneh et al., 1967; Seifu Gebremariam, 1996; Endale Tabogie et al., 1996; Mulugeta Diro et al., 1996; Taye Bezuneh, 1996). Seifu Gebremariam (1996) listed the major problems in Enset production

1 Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia. E-mail: [email protected] 38 Endashaw Bekele such as land fragmentation and population increase, nutritional, and production constraints due to disease, lengthy cultural practices and labour intensive processing. Mulugeta Diro et al. (1996) and Morpurgo et al. (1996) reviewed the propagation studies of the crop until 1993. These review papers, in general, covers the attempts made since the 1980’s on collection, evaluation and maintenance of germplasm; clonal and environmental agronomic trials with NP fertilizers, frequency of transplants, population density, selection of suitable intercrop and observation on ecological adaptation. The research effort so far made on enset has been limited given the importance of the crop in the Ethiopian traditional agriculture and culture. Consequently, there are several gaps to be filled and research topics to be covered with interdisciplinary approach by involving many national institutions. The research on micropropagation and diversity studies conducted by Genet Birmeta et al. (2004) and enset production and productivity studies of Admasu Tsegaye and Struik (2002) considerably contributed to the understanding of enset. The other recent research progress has been on the physico-chemical properties of enset starch which can be locally produced in abundant quantities for industrial application in the manufacturing of products such as food, textile, paper, adhesives and pharmaceuticals. Tsige Gebre-Mariam and Schimidts (1996) and Tsige Gebre-Mariam et al. (1996) provide information on its composition, morphology, and selected physico-chemical characteristics of the starch of Ensete ventricosum and that proved useful when considering various applications of the starch such as in the pharmaceutics and the food industries. According to Tsige Gebre-Mariam and Nikolayev (1993), enset starch can be used both as a tablet binder and disintegrant with a better binding ability and less disintegrating power than potato starch. The disintegration time for the tablets of chloroquine phosphate, dipyrone and paracetamol made with enset starch fall within the British pharmacopoeia limits for disintegration time of unloaded tables (Tsige Gebre-Mariam and Nikolayev, 1993). The fact that the first food (called Safna) which is a special water squeezed from the enset pseudo stem) to be ceremonially given to the newly born baby before breastfeeding in Ari community (South Omo, Ethiopia) as reported by Shigeta (1997) quoting Gebre Yntiso (1996) may also be linked to its possible medicinal value due to some active component it might possess. Ethiop. J. Biol. Sci., 17(Suppl.): 37–49, 2018 39

In general, enset starch quality and its industrial application as well as the active chemicals it possesses for anti-tumor, anti-nematidic and anti- bacterial treatment adds value to enset use and its contribution to sustainable development and poverty alleviation of the enset to rural communities. The very limited accounts on the origin and domestication of Ensete ventricosum, based on some inferences from cultural, folk systematics, historical, climatic changes, early food production and processing, and lack of archaeological evidence necessitated the need to use chloroplast, ITS and RAPD data (Endashaw Bekele and Shigeta, 2011). Study on the centre of origin of enset and its domestication is of particular significance to its utilization, improvement and understanding of enset-man interaction and the effect of these on both natural and man-made ecosystem and the impact they make on the origin, evolution and diffusion of culture which are the very bases of adaptation and survival of the indigenous communities of enset culture. The Genera Ensete and Musa The genera Ensete Horan and Musa L. are grouped in the order , family Musaceae. Zingiberales is phylogenetically embedded within the derived eumonocots (Arecales, Commelinales, Poales). The order includes many conspicuous taxa, including banana (Musaceae), bird of paradise (Stretitziaceae), heliconia (Heliconiaceae), and ginger (Zingiberaceae) (Kress et al., 2002). The Musaceae, Stretitziaceae, Lowiaceae, and Heliconiaceae constitute a basal paraphyletic group. This is a non-monophyly grouping that is based on shared primitive or original state characteristics (plesiomorphies) and hence typically excludes one or more taxa with unique derived characters (autapomorphies). These families are ancestral to the sister groups Zingiberaceae+Costaceae and Cannaceae+Marantaceae, which together form a monophyletic terminal lineage (Manchester and Kress, 1993) with groupings that are based on shared primitive characters and exclude autoapomorphic taxa with unique derived character states. Musaceae represents the most basal lineage in the order, based on a tree derived from maximum parsimony analysis of morphological characters (Kress, 1990). The three extant genera of Musaceae are Musa L., which was originally restricted to Asia (n = 7, 9, 10, 11); Ensete Bruce ex Horan, which is distributed in Africa, America, and Asia (n = 9); and Musella (Fr.) C.Y. Wu ex H.W.L., which is a monotypic genus endemic to Southern China (n = 9). 40 Endashaw Bekele

Although another species, Musella splendid, from Vietnam has been reported (see Valmayor and Phillip, 2002), many authorities consider this to be Musella lasiocarpa. Cultivated bananas are sterile seed diploid, triploid, or tetraploid clones with various combinations of the A and B genomes from two diploid species of Musa, namely, M. acuminata L.A. Colla (AA genome) and M. balbisiana L.A. Colla (BB genome) (Simmonds and Shepherd, 1955). These wild relatives of edible bananas originated in Southeast Asia (Simmonds, 1962; 1966). As edible bananas are seedless, the presence of vegetatively propagated plants in most tropical regions is necessarily the result of human activities and somatic mutations. Musa acuminata and M. balbisiana have played a major role in the complex domestication process of Musa (Simmonds, 1962; Simmonds and Shepherd, 1955). Parthenocarpic, vegetatively propagating cultivars of the genus Musa have diversified mainly because of the accumulation of spontaneous mutations. The genus Ensete is one of the smallest genus in the plant kingdom and belongs to the Family Musaceae, order Zingiberales (Tomilson, 1969). The relationship between the Ensete and Musa genomes has yet to be elucidated. Information on the relationship of E. ventricosum, a domesticated species, to other ancestral Ensete species and Musa is very limited. There are taxonomic problems in both genera, and some characters, such as the existence of natural suckers in Musa and their absence in Ensete, which are used to distinguish between the two genera, are not consistent, as there are some suckering clones of E. ventricosum (known as Entada and cultivated by Ari ethnic groups in Ethiopia (Shigeta, 1990) and limited and rare suckering enset clones (personal observation). Methods used for tracing the origin of Ensete Tracing the origin of enset and early food production in Ethiopia, the following sources of information were used (Endashaw Bekele, submitted for publication) 1. Historical evidence 2. Evidence from botanical, genetic and cultural sources 3. Evidences from food production and processing 4. Evidences from historical distribution of Ensete 5. Brandt Climatic periods based evidences Ethiop. J. Biol. Sci., 17(Suppl.): 37–49, 2018 41

6. Murdock’s suggestion, enset and livestock interaction and climatic change based evidence 7. Linguistic evidence 8. Evidences from botanical differences and diversity between wild and cultivated enset forms 9. Evidences from ecological association with root and tuber crops 10. Evidences from diverse forms of food preparation from enset 11. Evidence from ecologically isolated and dissected mountain terrains 12. Evidences from diverse use value of enset 13. Evidences from molecular genetic diversity and systematics of Ensete and Musa DISCUSSION ON THE CURRENT STATUS OF ENSET, GAPS AND CHALLENGES I. Taxonomic problems and species distributions in Ensete The taxonomy of the genus Ensete has not been fully resolved and remains a subject of debate, although the genus is among the smallest in the plant kingdom. Ensete ventricosum is a staple cultigen for much of the Ethiopian community, and its use is still expanding. In 1882, Horaninow, quoted in Baker and Simmonds (1953), was the first to propose Ensete as a new genus. Cheesman (1947) recognized 25 species, whereas Baker and Simmonds (1953) identified only about 8 distinct species, and Simmonds (1960) listed just 6 species, with 1 or 2 undescribed species in Thailand. The currently recognized species are E. gilleti, E. glaucum, E. homblei, E. perrieri, E. superbum, E. ventricosum, and E. wilsonii. Simmonds considered E. wilsonii to be E. glaucum and also, noting the absence of consistent differences between E. ventricosum and E. glaucum, it can be suggested that the former be reduced to the latter. It was also recommended that E. gilleti be reduced to a subspecies of E. ventricosum. Both Cheesman (1947) and Simmonds (1960) noted that M. martini Noter from Vietnam might belong to Ensete. E. gilleti De Wild is native to western Africa, and distributed from Sierra Leone to Angola, and is ecologically adapted to drier locations than other Ensete species. E. homblei Beq. ex De Wild is more like the canna and banana distributed in Congo and Zambia. Ensete perrieri is reported from Madagascar, and E. superbum Roxb is native to India. Ensete glaucum Roxb 42 Endashaw Bekele is distributed over a wide area from Burma to the Philippines and Java (Indonesia). Ensete ventricosum Two Ensete species might also occur in North America (Simmonds, 1960; 1962; Manchester and Kress, 1993). In Africa, E. ventricosum is the most widely distributed and highly variable species. It widely occupies the whole of central Africa, from Cameroon to Ethiopia and South Africa. Although generally adapted to swampy and moist areas throughout central and eastern Africa, it is cultivated only in Ethiopia, for food and fiber. In Ethiopia, the wild form of E. ventricosum is found at lower altitudes, in a relatively drier zone than the distribution of the cultivated form. Analysis of genetic diversity among cultivated enset (Ensete ventricosum) populations from Essera and Kefficho, South western part of Ethiopia using inter simple sequence repeats (ISSRs) marker resulted in clear demarcation of cultivated enset clones from various regions (Dagmawit Chombe and Endashaw Bekele, 2011). Endashaw Bekele and Shigeta (2011) have analyzed complete sequences of transcribed spacers and introns from the trnT-trnF region of chloroplast DNA (cpDNA) from Musaceae species to establish the phylogenetic relationships among 3 species of Ensete and 13 species of Musa. Parsimony analysis and pair-wise distance data produced a single tree, with Ensete and Musa as clearly distinguished clades. Six Musa and three Ensete clades were generated. The topology of these clades did not change when the data were split into spacers and introns, although the split resulted in poor bootstrap support. Removing a hotspot from the entire dataset improved clade support. The clades produced were discussed with reference to existing taxonomic treatments. In contrast to previous suggestions, most of the Rhodochlamys species that were investigated clustered together with strong support establishing their distinctiveness from the Musa species, s. Ensete glaucum and M. beccarrii appear to represent ancestral forms of Ensete and Musa, respectively, and both have a common ancestor that is yet to be established. Our data also showed that E. ventricosum cannot be reduced to E. glaucum, nor can E. gilletti be reduced to E. ventricosum, as some authorities have suggested. Ensete gilletti or a species very close to it appears to be the ancestral species of E. ventricosum.

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ORIGIN OF ENSET The following are major summaries and points accounting the centre of origin for Ensete ventricosum.  Agronomists and biogeographers have long considered the Ethiopia primary origin for enset agriculture.  Anthropologists, archeologists, and historians and other scholars argue for the domestication of enset in Ethiopia as early as 10,000 years ago.  Stiehler (1948) believed that the indigenous hunter/gatherer of southern Ethiopia were first to cultivate enset.  Some historians and botanists had earlier attempted to trace the origin of enset to ancient Egypt.  Writers, such as Smeds, 1955 suggested that enset cultivation originated in highland Ethiopia.  Smeds (1955) speculated that the present Wolaita-Kambata-Gurage regions, is the original centre of enset cultivation.  Murdock (1959) suggested sometime in prehistory “Sidamo tribe” of the southwestern Ethiopia independently brought enset under cultivation.  Ehret (1979) proposed theory based on largely upon historical and linguistic data that argue for much earlier date for the beginning enset food production (10,000 years ago).  Brandt (1996) proposed a model for the evolution of enset food production in Ethiopia by considering the following climatic periods: Terminal Pleistocene hyper aridity (ca 18-10,000 B.P) with initial domestication of enset and other plant foods; Early-middle Holocene climatic optimum (ca 10-5000 B.P) with population increase and colonization of new lands and beginning of deforestation; Middle-later Holocene (ca 5-2000 B.P) with the development of more complex social, economic and technological system: methods of postponing consumption and spoilage of crops i.e., fermentation and storage of enset in above and below-ground devices; Latest Holocene (.D. 500-1900) with the development of Ethiopian feudalism; increasing pressure on peasants to grow surplus/cash crops and eventual abandonment of enset and other 44 Endashaw Bekele

subsistence crops in North and Northwest. The genetic diversity parameters of the enset populations of SW Ethiopia studied is indeed high. The results based on ISSR is in agreement with other result obtained by AFLP (Almaz Negash et al., 2002), RAPD (Genet Birmeta et al., 2002) that indicated that the diversity and number of clones in enset cultivation regions could be as high as the number of vernacular naming used by local farmers. The higher within genetic diversity in cultivated enset observed by various studies could be due to:  The vegetative propagation mode of reproduction;  Other factor such as protection of enset clones due to cultural reasons;  The differential values obtained from each clones of the crop; and  Shannon diversity index and GD result showed that populations of enset from some sites are more diverse than populations from other areas. A clear separation with minor admixture between the enset clones from various regions have been noted with relatively high to medium level of gene flow detected and this may be due to exchange of materials between peoples of the various regions, therefore, gene flow will not be restricted between clones from the various regions. Morphological, cultural, use value and molecular diversity strongly suggest that Ari, Dawuro, Bonga and Sidama each with one site representation be selected as sites for in situ field conservation sites for E. ventricosum. RAPD and ITS data that were gathered demarcated the eight Musa species and cultivated and wild forms of Ensete ventricosum suggesting that different clones of cultivated enset seem to have originated from different clones of wild Ensete ventricosum. This suggests that several microcentres of domestication exist in the region. The wild and cultivated forms of Ensete ventricosum introgress to each other. The chloroplast DNA sequence data gathered from three species of Ensete and 13 species of Musa resulted in the following conclusions:  Three species of Ensete and thirteen species of Musa. Parsimony analysis and pair-wise distance data produced a single tree, with Ethiop. J. Biol. Sci., 17(Suppl.): 37–49, 2018 45

Ensete and Musa as clearly distinguished clades. Six Musa and three Ensete clades were generated. The topology of these clades did not change when the data were split into spacers and introns, although the split resulted in poor bootstrap support.  In contrast to previous suggestions, most of the Rhodochlamys species that we investigated clustered together with strong support establishing their distinctiveness from the Musa species studied. Ensete glaucum and M. beccarrii appear to represent ancestral forms of Ensete and Musa, respectively, and both have a common ancestor that is yet to be established.  The data also show that E. ventricosum cannot be reduced to E. glaucum, nor can E. gilletti be reduced to E. ventricosum, as some authorities have suggested. Ensete gilletti or a species very close to it appears to be the ancestral species of E. ventricosum. As shown below the three species of Ensete and 13 species of Musa Parsimony analysis and pair-wise distance data produced a single tree, with Ensete and Musa as clearly distinguished clades.

46 Endashaw Bekele

Fig. 1. Strict consensus tree of 3 species of Ensete and 13 species of Musa derived using parsimony analysis and pair-distance data. SYNTHESIS, KEY MESSAGES AND CONCLUSIONS The species composition of the genus Ensete is unsettled and need further treatments. The distributions of the various currently recognized species of the genus in Africa and Asia and a systematics account of its origin and domestication still has a gap. One of the reasons for the disputes on the centre of origin in literature is partly due to unclear demarcation between the concepts of centre of origin and centre of initial domestication of a given species. A molecular genetic data from RAPD, chloroplast and ITS DNA sequence suggest that different clones of cultivated enset seem to have originated from different clones of wild enset suggesting the existence of several microcentres of domestication in the region. These microcentres need to be further elaborated for in situ conservation site identification and implementation. While archaeological evidence is completely lacking, the inferred evidences on the origin and domestication of enset need critical treatments. The research effort on enset has moved very slowly and as a result there are still Ethiop. J. Biol. Sci., 17(Suppl.): 37–49, 2018 47 several gaps to be filled and research topics to be covered with a need for involvement of many institutions. The relationship between the Ensete and Musa genomes has yet to be elucidated. Information on the relationship of E. ventricosum, a domesticated species, to other ancestral Ensete species and Musa is very limited. There are taxonomic problems in both genera, and some characters, such as the existence of natural suckers in Musa and their absence in Ensete, which are used to distinguish between the two genera, are not consistent, as there are some suckering clones of E. ventricosum (known as Entada and cultivated by Ari ethnic groups in Ethiopia (Shigeta, 1990) and limited and rare suckering enset clones (personal observation). REFERENCES Admasu Tsegaye and Struik, P.C. (2002). Analysis of Enset (Ensete ventricosum) indigenous production methods and farm-based biodiversity in major enset- growing regions of southern Ethiopia. Exp. Agr. 38: 219–315. Almaz Negash, Admasu Tsegaye and Van treum, R. (2002). AFLP analysis of enset clonal diversity in south and southwestern Ethiopia for conservation. Crop Sci. 42: 1105– 1111. Baker, R.E.D. and Simmonds, N.W. (1953). The Genus Ensete in Africa. Kew Bull. 8: 405– 416. Brandt, S.A. (1996). A model for the origins and evolution of Enset food production. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 36–46 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings from the International Workshop on Enset held in Addis Ababa, Institute of Agricultural Research, Addis Ababa. Cheesman, E.E. (1947). Classification of bananas II. The genus Musa L. Kew Bull. 2: 106– 117. Dagmawit Chombe and Endashaw Bekele (2011). Analysis of genetic diversity among cultivated enset (Ensete ventricosum) populations from Essera and Kefficho, Southwestern part of Ethiopia using inter simple sequence repeats (ISSRs) marker. Afr. J. Biotechnol. 10(70): 15697–15709. Ehret, C. (1979). On the antiquity of agriculture in Ethiopia. J. Afr. Hist. 20: 161–177. Endale Tabogie, Mulugeta Diro and Bezuayehu Haile (1996). Enset improvement research: Past and present. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 228- 234 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings from the International Workshop on Enset held in Addis Ababa, Institute of Agricultural Research, Addis Ababa. Endashaw Bekele and Shigeta, M. (2011). Phylogenetic relationship between Ensete and Musa species as revealed by trnT-trnF region of cpDNA. Genet. Resour. Crop Evol. 58: 259–269. Endashaw Bekele (Submitted). The centre of origin and domestication of Ensete ventricosum and its taxonomic affinity to some Musa species. Gebre Yntiso (1996). Economic and socio-cultural significance of Enset among the Ari of Southwest Ethiopia. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 48 Endashaw Bekele

107–120 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings from the International Workshop on Enset held in Addis Ababa, Institute of Agricultural Research, Addis Ababa. Genet Birmeta, Nybom, H. and Endashaw Bekele (2002). RAPD analysis of genetic diversity among clones of the Ethiopian crop plant Ensete ventricosum. Euphytica 124: 315–325. Genet Birmeta, Nybom, H. and Endashaw Bekele (2004). Distinction between wild and cultivated enset (Ensete ventricosum) gene pools in Ethiopia using RAPD markers. Hereditas 140: 139–148. Horaninow, P.E. (1862). Prodromus Monographiae Scitaminarum. Academiae Caesareae Scientarum, St. Petersborg. Kress, W.J. (1990). The phylogeny and classification of the Zingiberales. Ann. Mo. Bot. Gard. 77: 698–721. Kress, W.J., Prince, L.M. and Williams, K.J. (2002). The phylogeny and a new classification of the gingers (Zingiberaceae): Evidence from molecular data. Am. J. Bot. 89(1): 1682–1696. Manchester, S.R. and Kress, W.J. (1993). Bananas (Musaceae): Ensete oregonense sp. Nov from Eocene of Western North America and its phytogeographic significance. Am. J. Bot. 80(11): 1264–1272. Morpurgo, R., Afza, R. and Novak, F.J. (1996). Biotechnology and Enset achievements and perspectives. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 256–270 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings from the International Workshop on Enset held in Addis Ababa, Institute of Agricultural Research, Addis Ababa. Mulugeta Diro, Bezuayehu Haile and Endale Tabogie (1996). Enset propagation research review. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 242–249 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings from the International Workshop on Enset held in Addis Ababa, Institute of Agricultural Research, Addis Ababa. Murdock, G.O. (1959). Africa: Its people and their Culture History. National Research Council. McGraw Hill, New York. Seifu Gebremariam (1996). Enset Research in Ethiopia: 1976-1984. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 204–220 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam. Proceedings from the International Workshop on Enset held in Addis Ababa, Institute of Agricultural Research, Addis Ababa. Shigeta, M. (1990). Folk in-situ conservation of Ensete ventricosum (Welw. E.E. Cheesman): Towards the interpretation of the indigenous Agricultural Science of the Ari, South Western Ethiopia. Afr. Stud. Monogr. 10(3): 93–107. Shigeta, M. (1997). Essence of indigenous sustainability and diversity: Enset system. In: Proceedings of the XIIIth International Conference on Ethiopian Studies, Ethiopia in Broader Perspective, Vol. 3: 883–892 (Fukui, K., Kurimoto, E., Shigeta, M., eds.). 12-17 December, Kyoto. Simmonds, N.W. (1960). Notes on banana taxonomy. Kew Bull. 14: 198–212. ______(1962). The Evolution of the Bananas. Longman, London. Simmonds, N.W. (1966). Bananas. 2nd edn. Longman, London. Simmonds, N.W. and Shepherd, K. (1955). The taxonomy and origins of the cultivated Bananas. J. Linn. Soc. (Bot.) 55: 302–312. Ethiop. J. Biol. Sci., 17(Suppl.): 37–49, 2018 49

Smeds, E. (1955). The Ensete planting culture of Eastern Sidamo, Ethiopia. Acta Geogr. (Helsingfors) 13(4): 1–39. Stiehler, W. (1948). Studien zur Landwirtschafts - und Siedlungsgeographie Athiopiens. Mit 3 Karten. Erdkunde 2: 257–282. Taye Bezuneh and Asrat Feleke (1966). The production and utilization of the genus Ensete. Acta Hortic. 21: 97–100. Taye Bezuneh, Asrat Feleke and Regassa Bayie (1967). The cultivation of the genus Ensete in Ethiopia. Proc. Soil Crop Sci. Soc. Fla. 27: 133–141. Taye Bezuneh (1996). An overview on Enset research and future technological needs for enhancing its production and utilization. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 1–14 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings from the International Workshop on Enset held in Addis Ababa, Institute of Agricultural Research, Addis Ababa. Tomilson, P.B. (1969). Anatomy of Monocotyledons III. Commelinales-Zingiberales. Clarendon Press, Oxford. Tsige Gebre-Mariam and Nikolayev, A. (1993). Evaluation of starch obtained from Ensete ventricosum as a binder and disintegrant for compressed tablets. J. Pharm. Pharmacol. 45: 317–320. Tsige Gebre-Mariam and Schimidt, P.C. (1996). Characterization of enset starch and its use as a binder and disintegrant for tables. Pharmazie 51(5): 303–311. Tsige Gebre-Mariam, Winnemoller, M. and Schimidt, P.C. (1996). An evaluation of the disintegration efficiency of a sodium starch glycolate prepared from enset starch in compressed tablets. Eur. J. Pharm. Biopharm. 43(2): 124–132. Valmayor, R.V. and Phillip, L.D.D. (2002). Musella splendid. Phillip. Agric. Sci. 85 (2): 204–209.

Ethiop. J. Biol. Sci. 17(Suppl.): 51–62, 2018 © The Biological Society of Ethiopia, 2018 ISSN: 1819-8678 ENSET (ENSETE VENTRICOSUM, MUSACEAE) ETHNOBOTANY: RESEARCH STATUS, GAPS AND KEY MESSAGES

Zemede Asfaw1

ABSTRACT: Enset (Ensete ventricosum (Welw.) Cheesman, Musaceae) is an ethnobotanical icon considering its economic, sociocultural, environmental and symbolic roles. This paper reviews how far the enset research undertaken so far has taken up its ethnobotany. The objective is identification of the specific gaps and casting hints on ethnobotanical research that needs to be undertaken in future efforts for an understanding of the place of enset and its system in the life of the people who care for it. Considering the scope of studies and the recent methodological advances in ethnobotany, it is imperative to see how far previous enset research has benefited from it in data collection and analyses and what enset has missed. The current trend in enset ethnobotanical research along with the gaps and key messages vis-à-vis perspectives of sustainable development take the main thrust in this review. The review showed that cross-disciplinary and cross- cultural data are inadequate and applications of recent ethnobotanical methodologies are at low level. Aspects of cognitive ethnobotany, quantitative ethnobotany and coverage of the full range of enset culture with same research protocol are areas not covered. Furthermore, ethnobotanical modeling of the enset system has not been researched. The paper targets the major gaps and key messages for embarking upon full scale enset ethnobotany research. It is hoped that the ideas will serve as basis for initiating future ethnobotanical research on enset that engages both qualitative and quantitative approaches in an integrated and balanced manner.

Key words/phrases: Agroecology, Common research protocol, Ethnobotanical modeling, Meta-analysis, Quantitative enset ethnobotany.

INTRODUCTION The reciprocal relationship between the enset (Ensete ventricosum (Welw.) Cheesman, Musaceae) crop and the people who manage the crop and use its products can best be studied in the scientific dominion of enset ethnobotany. Enset is one of the major staple/co-staple food crops with many more use values. It is widely cultivated in the southern and southwestern parts of Ethiopia. The species occurs in a wide range of agroclimatic zones, all the way from about 1200 to 3300 metres above sea level and its cultivation primarily as a food crop happens in the range of 1450-3300 m stretching

1 Department of Plant Biology and Biodiversity Management, College of Natural and Computational Sciences, Addis Ababa University, P.O. Box 3434, Addis Ababa, Ethiopia. E-mail: [email protected]; [email protected] 52 Zemede Asfaw from the hot moist lowlands to the cold sub-humid sub-afroalpine and afroalpine highlands (Fig. 1). Where enset is cultivated, it plays critical roles in the livelihoods of about 20 million Ethiopians, providing a range of services as food, forage, medicine and maintenance of environmental health as well as with a number of socio-cultural roles as a symbolic plant used for condolences and rituals (Gebre Yntiso, 1996). It is a species where farmers recognize individual plants in their gardens and where the human-plant bondage is extremely strong partly due to the long history of use by different cultures. The role of human culture in agro-biodiversity use and management becomes very visible in the reciprocal interactions observed between the enset plant and the people in the enset zone. Thus, it is an ideal plant for application of a mix of qualitative and quantitative ethnobotanical approaches in research in order to explicate the knowledge encoded in the stories, poems, rituals, oral literature and the wide array of other practices and knowledge domains. Ethnobotany has a collection of research tools and techniques appropriate for the study of indigenous botanical knowledge of useful plant species. It becomes even much more useful with many practical values when the plant of interest is a food crop, indigenous, has long history of use in multiple cultures (Brandt et al., 1997), as food, part of traditional medicine, in the peoples’ material culture (Gebre Yntiso, 1996) and many other use values and this is the case with enset. Enset satisfies all these and other related attributes and would greatly benefit from a full-blown comprehensive ethnobotanical investigation. One of the main reasons why ethnobotanists and ethnoecologists concern themselves with the collection and analysis of indigenous and local knowledge on crop species and their ecology is to be able to present the knowledge in a scientifically sound format. Indigenous botanical knowledge retrieved and organized following scientifically permissible procedures is critical as a source of evidence not only to justify the scientific worth of such knowledge but also to customize it for practical application. Ethnobotanical research requires elaborate studies applying both qualitative and quantitative approaches and this is achieved through extensive data collection and deep analyses taking various locations, agroecologies and communities. It is further noted that ethnobotany is a relatively new addition in science and that quantitative ethnobotany is known only since 1987. It was initially used in forest research, later applied to individual plants, and then to some crops. Up to recently, it has been undergoing methodological refinements; and not well understood and practiced by many. The strength of ethnobotany is related to the strengths of Ethiop. J. Biol. Sci., 17(Suppl.): 51–62, 2018 53

15

21 8- Warm sub-moist lowlands 27 13- Hot moist lowlands 14- Warm moist lowlands 15- Tepid moist mid highlands Enset Zone 16-Cool moist mid highlands 19- Hot sub-humid lowlands 20- Warm sub-humid lowlands 32 21- Tepid sub-humid mid highlands 8 28 22- Cool sub-humid mid highlands 26 26- Tepid humid mid highlands 27- Cool humid mid highlands 16 31 28- Cold sub-humid sub-afro-alpine to alpine 20 22 31-Warm per-humid lowlands L 32- Tepid per-humid mid highlands

14 13 19

Data Source: EIAR (2011)

Fig. 1. Map of Ethiopia showing enset cultivation areas with agroecological zones. 54 Zemede Asfaw its disciplinary pillars (botany, ecology, anthropology, mathematics and other related fields), thus requiring being conversant in these and other related fields. Ethnobotany is a helpful discipline in the enhancement of the crop and building its profile further firming up comprehensive understanding in a scientific context. The knowledge generated in this way is used for improving the production and utilization of the crop species. In this regard, it would be good to see how far formal science has come or lagged behind in the case of enset, which is an indigenous staple, emblematic, symbolic and charismatic species commonly seen in the living compounds of households in the midland areas of Ethiopia. Sources of information Fragmented facts about enset ethnobotany mainly dealing with vernacular names of landraces and uses were collated through Internet browsing at Google scholar and other means. A large number of research reports and sources including books, articles, theses and personal observations were reviewed. Furthermore, viewpoints that frequently transpire in formal and informal discussions and debates were assessed. The resulting information was viewed in the context of the current state of ethnobotany and to see the gaps and challenges. The findings were then synthesized to sift out the key messages that emerge. Thus, review and recollection of scattered facts and critical reflections on the way forward constituted the main thrust in the preparation of this review and analyses on the current state of enset ethnobotany in Ethiopia. CURRENT ETHNOBOTANY RESEARCH STATUS, GAPS AND CHALLENGES Current status Skimming through the Enset literature shows that some studies have touched upon its ethnobotany even though most of the early works neither called it ethnobotany nor applied standard ethnobotanical/ethnoecological methodology. Furthermore, many of the studies that presented ethnobotany- like narratives on enset tended to be more of compilations of checklists (Zippel, 2002; Almaz Negash and Niehof, 2004) and short profiles of vernacular names of clones (farmers’ varieties/landraces) that were shaped over generations and maintained for millennia. Another aspect that went on being researched was the utilitarian aspect of the different parts of the plant as well as of the standing crop. There has been a lot of interest to understand enset and its system right from the days of James Bruce (who produced a Ethiop. J. Biol. Sci., 17(Suppl.): 51–62, 2018 55 drawing of the plant along with 200 species of Ethiopia’s indigenous useful plants). Foreign travelers, explorers and resident researchers of different disciplinary areas have written about enset but its ethnobotany did not go beyond recording vernacular names and uses for a long time. Westphal (1975) described the enset cultivation system and Okigbo (1990) depicted the system as a homegarden agrosystem while Zemede Asfaw and Ayele Nigatu (1995) focused more on plant diversity and Zemede Asfaw and Zerihun Woldu (1997) dealt with crop associations in homegarden system wherein enset is the key species. Admasu Tsegaye (2002), noting the keen description that enset growing farmers could provide including by considering it the enemy of famine, rightly underlined the practical values of the knowledge of the local people regarding use, diversity, productivity and adaptation to agroecological settings. At this juncture, it is worth noting that the local knowledge documented by researchers can be integrated with formal science to optimize the management of enset agrobiodiversity in association with the companion crops, and this will contribute to the improvement of farming systems as well as preservation of the bio-cultural heritages. Some among these researchers have applied limited methods of ethnobotany in their efforts to understand the enset system (Shigeta, 1991; Yemane Tsehaye and Fassil Kebebew, 2006; Sato, 2009; Talemos Seta et al., 2013). However, most works of the past often had heavier hands on botanical, agronomic and anthropological perspectives. From the varied studies, a host of utilitarian attributes of enset have cumulated over the years (Fig. 2). At most, such studies were overwhelmingly dominated by utilitarian and qualitative approaches in their ethnobotanical drive and belong to the general category of basic ethnobotany that largely relied on qualitative data. The primary reason for the dominance of such approaches is the underdeveloped nature of ethnobotany at global level in general, and in Ethiopia in particular. The current era of quantitative ethnobotany expects more rigorous research through balancing qualitative and quantitative approaches particularly focused on the grey area in enset research.

56 Zemede Asfaw

Food/ Medicine Making House Human, Livestock Furniture, mat, Construction Feed (edible parts, root, leaf) souvenirs huts, sheds, fences, etc. Material Culture (sacs, containers) Thatching, house Source of high quality decorations Fibre for sacs, basketry, ropes, bags, other cordage Household Utensils/Implements, Plate for food, , hats, coffee pot backpacking, accessories Enset Use umbrella, wrapping Diversity Mulch & Soil Toys for children fertility (toy guns, toy vehicles, enhancement (Studies have shown toy horses) uses of the plant and Ecological/ its products in the environmental provision of various Ritual, spiritual, services, emblematic, adaptation to goods & services) climate change ornamental roles

Fig. 2. Facts compiled in previous studies on the uses of enset compiled from different sources. Major research gaps The ethnobotany of enset has been touched by many research works in one way or another, albeit the disconnected and variable nature in contents, scope and methods. This is mainly because a full scale cross-cutting enset ethnobotany has never been undertaken across all cultures and agroecological zone of its production and food systems. The limited ethnobotanically-oriented studies have generally been incomplete and lacked adequate coverage. There has been no formal research with the primary goal focused to the ethnobotany of this crop. Earlier studies have generally been ancillary to other studies and are with incomplete coverage and methodological disparities. Similarities and differences in the ethnobotanical knowledge of communities belonging to the Omotic, Nilotic, Cushitic and Semitic stocks and to the ethnicities within each of them have not been investigated and satisfactorily addressed, though of both academic and practical relevance. Some studies of enset ethnobotany were undertaken on isolated sites and cultures and fail short of providing a complete story of the bigger picture while others written in some foreign languages have not Ethiop. J. Biol. Sci., 17(Suppl.): 51–62, 2018 57 been accessible to young resident researches. Since enset cultivation enjoys a wide latitudinal and altitudinal stretch engaging different ethno-linguistic communities, a much richer ethnobotanical/ethnoecological role can be hypothesized. There is, therefore, a real need to examine the depth and breadth of enset ethnobotany in the different cultures and agroecological zones re-defining new approaches and methodologies. The research gaps can be seen under lack of sufficient cross-disciplinary data and paucity in the application of a broad range of ethnobotanical methods derived from botany, ecology, anthropology, economics and related fields. Application of mathematics, statistics and computational tools is also at low level. Enset ethnobotany is in a fragmented state with variable content, scope and methodological spectrum. Full scale enset ethnobotany research across cultures as well as agroecological and livelihood zones is not known. There was no formal research primarily targeting enset ethnobotany and most studies focused at few communities or locations. Known studies are in most cases incomplete, lacked adequate coverage in many aspects with noticeable methodological disparities. The research mostly lacked hypothesis testing and application of statistical methods even though the species is an excellent and a very ideal candidate for ethnobotanical research on account of observations made so far, the available research outputs and its history and origin. The available ethno-data are insufficient, not allowing comparisons across cultures, locations, agroecologies and livelihood zones. A monograph on enset ethnobotany is lacking as the data is incomplete/insufficient and short of being inclusive. Among other aspects, the review showed that there is lack of sufficient cross-disciplinary and cross-cultural data; paucity in the application of recent ethnobotanical methods/tools and low level of application of computational tools. Cognitive aspects, quantitative ethnobotany, coverage of the entire enset culture, communities and agroecologies and ethnobotanical modeling of the enset system are the most disregarded aspects in research. The challenges Ethnobotany research presents challenges of different types and magnitude even though it offers some opportunities. In Table 1, the main opportunities are presented with the possible challenges that may hinder enset ethnobotany research in future efforts.

58 Zemede Asfaw

Table 1. Opportunities and challenges in enset ethnobotany research. Opportunities Challenges Many agroecological zones, administrative areas, different Ethnobotany is undergoing development, cultural backgrounds. This good for comparisons, sorting the training needs are high budget shortage may common heritages and capturing the unifying features as well as prevail as it has been hitherto studying the unique knowledge of different groups. Very many (more than 20 million people) cultivate it for major Low number of trained ethnobotanists; uses and it involves more than 20 ethnoliguistic communities. limited capacity to apply the methods This offer a rich material and knowledge pool to learn from. accurately and the usual misconceptions and biases against ethnobotany Many households outside enset growing areas keep one or two Disparity in research methodology and enset plants in homegardens for minor uses (ornamental, approach when different researchers work wrapping, baking, etc.), which provide additional indigenous separately without coordinating their research knowledge (IK) source methodologies and making collective decisions Rich crop use diversity and genetic diversity; presence of wild Incomplete and unequal coverage of enset genes widening options for describing the use modes in a cultivator communities and areas of comparative manner and presence of companion crops (e.g. cultivation Brassica carinata) Generate data that can help to explain and answer some of the Lack of necessary background studies for problems mentioned by many, prepare ethnobotanical profiles of many enset cultivator communities and areas locations, communities and groups, distinct landraces SYNTHESIS AND KEY MESSAGES The research gaps identified in this review need to be addressed through sustained application of comprehensive ethnobotanical methods. The areas of enset cultivation have to be matched with the new agroecological zones of Ethiopia (EIAR, 2011) and the ethnic identities have to be handled by the method of meta-analysis of data derived from all key areas as a minimum. Such an approach will show the aspects of similarities among and between areas as well as the differences. Unless a full scale ethnobotanical research is deployed on enset, it will not be easy to unwind the “story” of this crop, which has been ‘written up’ by generations of farming communities and a legacy inherited from ancient hunter-gatherer ancestors (Brandt, 1996; Brandt et al., 1997) of its present-day cultivators and user farmers. The knowledge to be captured and analyzed is knowledge that has been accumulating for thousands of years and will not give in hands unless the state of the art in ethnobotany science is applied. A better future for enset and those who make their livelihoods on it can be realized with such an approach and the crop and the people will stand to serve one another as it has always been. Thus, enset has to serve the people while being served by them. The paper finally pledges to provide hints to the desirable forward steps in its key messages. Some plausible ideas about the ethnobotanical research direction that could be realized as research problems for subsequent investigation in reflective peer actions are given as follows:

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1. Identify major enset culture areas and agro-ecological zones along with those considered marginal for its cultivation. With the help of GIS data generate distribution maps by zones and weredas superimposing the new agro-ecological zones (EIAR, 2011) and the ethnicities to see the results of interaction between agro-ecology and culture (language/ethnicity) and other comparison parameters; 2. Use same (common) ethnobotanical research protocol (same set of structured interview questions) across key locations and cultures and apply this and other methods to locations and communities to study enset ethnobotany. In this connection, it is important to bear in mind that Westphal (1975) and later other researchers (e.g. Zerihun Doda, 2007) considered that for the Gurage, Hadya, Kambata, Tambaro Sidama and Gedeo ethnic communities, enset is a vital staple food while for the Wolayta, Gamo, Gofa, Amaro, Yem, Kafitcho and others the crop is a co- staple with cereals. Other communities including the Aari, Sheko, Siltie, Konso, Dawro, Konta, Dizi, some Oromos and others also use enset to a greater and lesser extent and this situation has been dynamic. The magnitude of use and cultivation of enset vis-à-vis other crops has been shifting from one side to the other and this has to be looked into. A partial identification of enset cultivation areas and the cultivator communities has been collated from various sources, including Shigeta (1991); Zippel (2002); Zerihun Doda (2007), is given in Fig. 1 and Table 2. 3. Carry out key informant interviews across key locations and cultures with guided ethnobotanical field tour/walk interviewing farmer conservators and indigenous experts and conduct analysis on preferences, priorities, consensus factors, ranks comparisons and calculate indices of cultural significance, importance, relative importance and other data sets. 4. Apply mathematics, statistics and relevant computational tools of quantitative ethnobotany; 5. Prepare checklists of vernacular names of enset landraces and material culture made from enset for the different locations/ethnicities noting cognate names;

60 Zemede Asfaw

Table 2. Enset cultivation areas by region, zone/wereda and ethnic relations and identities. No Region Zone/Wereda People Language Family 1 Southern Nations, Wolayta Zone Welayta Omotic 2 Nationalities and Yem Special Wereda Yem Omotic Peoples Region 3 Gamo Gofa Zone, Gamo Wereda Gamo Omotic 4 Gamo Gofa Zone, Gofa Wereda Gofa Omotic 5 Dawro Zone Dawaro Omotic 7 Konta Special Wereda Konta Omotic 8 Basketo Special Wereda Basketo Omotic 9 Keffa Zone Kafficho Omotic 10 Sheka Zone Sheko Omotic 11 Bench-Maji Zone Bench, Maji, Dizi Omotic 12 South Omo, North Aari Wereda Aari Omotic 13 South Omo, South Aari Wereda Aari Omotic 14 Gurage Zone Gurage Semitic 15 Silti Zone Siltie Semitic 16 KebenaWereda Kebena Semitic 17 Sidama Zone Sidama Cushitic 18 Gedeo Zone Gedeo Cushitic 19 Kembata-Tmbaro Zone Kambata, Tambaro, Cushitic Alaba 20 Hadiya Zone Hadya Cushitic 21 Segem Zone, Konso Wereda Konso Cushitic 22 Oromia Region Arsi Zone, KofeleWereda Oromo Cushitic 23 Arsi Zone, KokosaWereda Oromo Cushitic 24 West Shewa Zone, Wenchi Oromo Cushitic Wereda 25 West Shewa Zone, Jibat and Oromo Cushitic Mecha Wereda 26 Jimma Zone Oromo Cushitic 27 Gambela Region Majang/Majanger Nilotic Source: Shigeta (1991); Zippel (2002); Zerihun Doda (2007), and others 6. Map the food, medicinal, environmental, fodder, emblematic/cultural and other roles of enset and its landraces; 7. Sort similar ethno-varieties, use categories, management and cultural (cosmovision) blocks and likewise make note of differences and generalizations that can be drawn up for hypothesis testing in either case; 8. Collect culture, location, gender, language disaggregated and aggregated data sets to facilitate in-depth analyses; 9. Collect indigenous knowledge (IK) through analysis of poems, songs, sayings, beliefs and enset ethnotaxonomy to know people’s levels of understanding (cognitive domain) and attitudes towards enset; 10. Study ethnobotany of crops associated with enset cultivation system and their compatibilities including the ethnobotany of wild enset (eppo in Ethiop. J. Biol. Sci., 17(Suppl.): 51–62, 2018 61

Keffa); 11. Carry out a multi-stage analysis and generate comparative ethnobotanical data and conduct an overall (and group) meta-analysis; and 12. Use the agro-ecological, agro-biodiversity and ethnicity data and attempt ethnobotanical modeling (Benifez et al., 2016) of the enset production system of key locations in Ethiopia. REFERENCES Admasu Tsegaye (2002). On Indigenous Production, Genetic Diversity and Crop Ecology of Enset (Ensete ventricosum (Welw.) Cheesman). Ph.D. Thesis, Wageningen University and Research Centre, the Netherlands. Almaz Negash and Niehof, A. (2004). The significance of enset culture and biodiversity for rural household food and livelihood security in southwestern Ethiopia. Agr. Hum. Values 21: 61–71. Benifez, G., Malero-Mesa, J. and Gonzalez-Tejero, M.R. (2016). A model to analyze the ecology and diversity of ethnobotanical resources for Granada Province, Spain. Biodiv. Conserv. 25: 771–789. Brandt, S.A. (1996). A model for the origin and evolution of enset food production. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 36–46 (Tsedeke Abate, Steven, C.H., Brandt, A. and Seifu Gebremariam, eds.). Proceedings from the International Workshop on Enset held in Addis Ababa, Institute of Agricultural Research, Addis Ababa. Brandt, S.A., Spring, A., Hiebsch, C., McCabe, J.T., Endale Tabogie, Mulugeta Diro, Gizachew Wolde-Michael, Gebre Yntiso, Shigeta, M. and Shiferaw Tesfaye (1997). The “Tree against Hunger”: Enset-Based Agricultural Systems in Ethiopia. American Association for the Advancement of Science with Awassa Agricultural Research Center, Kyoto University, Center for African Area Studies and University of Florida, Washington, DC. EIAR (Ethiopian Institute of Agricultural Research) (2011). New agroecological map of Ethiopia. Coordination of National Agricultural Research System, Ethiopia. EIAR, Addis Ababa. Gebre Yntiso (1996). Economic and socio-cultural significance of enset among the Ari of southwestern Ethiopia. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 1119–1121 (Tsedeke Abate, Steven, C.H., Brandt, A. and Seifu Gebremariam, eds.). Proceedings from the International Workshop on Enset held in Addis Ababa, Institute of Agricultural Research, Addis Ababa. Okigbo, N.B. (1990). Homegardens in tropical Africa. In: Tropical Homegardens, pp. 21– 40 (Landauer, K. and Brazil, M., eds.). United Nations University Press, Tokyo. Sato, Y. (2009). Ethnobotanical study of local practices maintaining landrace diversity of bananas (Musa spp.) and Enset (Ensete ventricosum) in East African Highland. Kyoto University Kyoto Working Papers on Area Studies No.61 (G-COE Series 59) Information Depository. Shigeta, M. (1991). The Ethnobotanical Study of Enset (Ensete ventricosum) in Southwestern Ethiopia. Ph.D. Dissertation, Center for African Area Studies, Kyoto University. 62 Zemede Asfaw

Talemos Seta, Sebsebe Demissew and Zemede Asfaw (2013). Home gardens of Wolayta, Southern Ethiopia: An ethnobotanical profile. Acad. J. Med. Plants 1(1): 014–030. Westphal, E. (1975). Agricultural systems in Ethiopia. Agricultural Research Report No. 826, College of Agriculture, Haileselassie I Univ., Addis Ababa and Agricultural Univ. of Wageningen, Wageningen. Yemane Tsehaye and Fassil Kebebew (2006). Diversity and cultural use of Enset (Enset ventricosum (Welw.) Cheesman) in Bonga in-situ Conservation Site, Ethiopia. ERA 4: 147–157. Zemede Asfaw and Ayele Nigatu (1995). Homegardens in Ethiopia: Characteristics and plant diversity. SINET: Ethiop. J. Sci. 18(2): 235–266. Zemede Asfaw and Zerihun Woldu (1997). Crop association of homegardens in Welayta and Gurage zones in Southern Ethiopia. SINET: Ethiop. J. Sci. 20(1): 73–90. Zerihun Doda (2007). An ethnographic overview of enset producing peoples of Ethiopia. Report presented at the Enset Research Review Workshop. Retrieved on September 16, 2016. Zippel, K. (2002). Enset (Ensete ventricosum (Welw.) Cheesm.) in subsistence farming systems in Ethiopia. Paper presented at the Conference on International Agricultural Research for Development, October 9-11. Witzenhausen, Deutscher Tropentag.

Ethiop. J. Biol. Sci. 17(Suppl.): 63–73, 2018 © The Biological Society of Ethiopia, 2018 ISSN: 1819-8678 IMPROVING INDIGENOUS KNOWLEDGE OF PROPAGATION FOR THE DEVELOPMENT OF ENSET AGRICULTURE: PROMOTING FARMERS’ ADAPTATION CAPACITY TO CLIMATE CHANGE

Laila M. Karlsson1,*, Abitew Lagibo Dalbato1 and Tamado Tana2

ABSTRACT: In order to provide knowledge for enset agriculture, seed germination, seedling development and vegetative reproduction were studied to envisage improved cultivars by crossing and selection and to enhance on- farm practices by acknowledging and evaluating farmers’ indigenous knowledge. Seed set vary considerably for enset, and the factors influencing fruit and seed developments should be studied further. Seed germination vary between seed lots from different mother plants, and requires additional studies even though placing the seeds on moist sand gives some germination from most seed lots. There was informal information that corms buried for vegetative reproduction would rotten if manure was applied directly on them or if they were watered. However, these two treatments gave large and strong suckers. When the corm was split in smaller (about 1 dm3) pieces, emergence was quicker and total production was higher than if the corm was kept entire. However, if there is risk for extended drought, using an entire corm is preferred for its water holding capacity. In the case of complete absence or little precipitation, watering on buried corm is beneficial if water is accessible.

Key words/phrases: Conventional breeding, Seed germination, Seed morphology, Seedling, Vegetative propagation.

INTRODUCTION Enset agriculture contributes to soil fertility and environmental sustainability as any perennial crop by avoiding or reducing erosion and keeping nutrients and moisture. Enset fields have higher soil organic matter and nutrients than other fields (Asnaketch Wolde Tensaye et al., 1998). Similar to forests, enset is a carbon dioxide sink (Mesele Negash and Starr, 2015). Enset is known as a drought-tolerant crop, it is said that there was no starvation among enset-growing farmers during famines in the 1970s and 1980s (Brandt et al., 1997). As food resource, enset is similar to potato (Mohammed et al., 2013), and it gives the highest yield in terms of edible energy per area and time unit of crops grown in Ethiopia (Admasu Tsegaye

1 Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden. E-mail: [email protected], [email protected] 2 Department of Plant Sciences, Haramaya University, Haramaya, Ethiopia. E-mail: [email protected] *Author to whom all correspondence should be addressed

64 Laila M. Karlsson et al. and Struik, 2001). Enset agriculture has for long proven as farmers’ adaptation strategy to climate change effects. It has obviously a wide range of economic, social and environmental benefits. Enset propagation, management and food processing techniques rely on indigenous technical knowledge of farmers. In nature, wild enset is reproduced through seeds when mature mother plant ends life cycle, new plants grow from seedlings. Further, when enset is grown as ornamental plant around the world (Cheers et al., 2004) or simple as a source of wrapping material or similar, seeds may be used for propagation. For food utilisation, enset is usually harvested at the onset of flowering, when corm, pseudostem and flower stalk are fresh, thus not allowing seed set other than randomly. As there has not been a conscious breeding for genotype improvement, farmers use the same landraces as always. They propagate with vegetative methods (i.e., cloning), by burying a corm with removed apical meristem, which gives about 30-100 new plants (Karlsson et al., 2015) with the same characteristics as the parent plant, and farmers are well aware that this method preserves the familiar plant quality. This propagation method is a wise decision of farmers, because seeds produce new and unknown plants due to genetic recombination which occurs under sexual reproduction. Thus, the plants with genetic variation may not possess the desired phenotype for the intended purpose, if seedlings are used directly. However, seedlings can be selected and used for genotype improvement through conventional breeding. Areka Research Centre (the national centre for enset research) released six landraces as cultivars with described characteristics (Mikias Yeshitila et al., 2011), but there are requests for novel characteristics and new combinations of characteristics. It is necessary to encourage farmers, increase research and extension efforts to maximise the benefits of enset agriculture. This includes acknowledging indigenous knowledge; which is for example important to mitigate climate change effects by maintaining and developing local agriculture and forestry (IPCC, 2014), but also investigating the efficiency in farmers’ inherited knowledge – just because one method functions and is utilised it is not necessarily the best possible method. Our aim is to provide knowledge for enset agriculture. We have studied (1) seed germination and seedling development and (2) vegetative reproduction.

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METHODS Seeds and seedlings Seed collection Collection sites were within the area Sodo – Tercha – Wolkite – Asela – Haramaya, i.e. N 06°50'–N 09°25', E 37°11'–E 42°02', in Ethiopia (Karlsson et al., 2013a;b). During seed collection, all encountered plants that had reached fruit stage were checked for seeds, and seeds per plant and fruit were counted. Seeds from 14 enset plants were collected at maturity, when the fruits were deep orange to brown. At this stage, the seeds were dark and very hard, and completely filled. Seeds came from either wild or cultivated plants. After collection, seeds were separated from the fruit flesh and dried before stored until onset of each experiment. Seed morphology and germination Seed morphology was studied in 117 seeds, by observing, measuring (precision 0.01 mm: seed coat in three dimensions and embryo width and length) and placing additional 200 seeds with different water contact to investigate water uptake. For germination test, totally 805 seeds from eleven mother plants (one mother plant equal one replicate) were placed on moist sand at ca. 25°C. Seeds were also subjected to physical and chemical treatments known to induce germination for so called hard coat seeds. Germination was recorded at least bi-weekly during 52 weeks (Karlsson et al., 2013a). Seedling growth Newly germinated seeds were planted in pots, after recording seed-size in three dimensions, and subjected to local soil only, local soil with manure or local soil with 1, 2, 4 or 8 g of DAP (Grade 18-46-0 [N-P-K, Ammophos, Cherepovet, Russia], containing 18% N and 20% P [IPNI, 2013]). Totally 412 seedlings were planted and placed within a fenced plot at Wolaita Sodo University campus (N 06°50'00'' E 37°45'08'', 1891 m a.s.l.), Ethiopia. Seedling characteristics were recorded after three weeks and after six months of growth. Additional ten seedlings were planted directly in the field, soil mixed with dry cow manure, when five weeks old and thereafter allowed to develop freely (Karlsson et al., 2013b). Twenty newly germinated seedlings were planted in pots with ceramic pellets and placed with light daytime (ca. 100 μmol m-2 s-1, 12 h) at ca. 20°C. These seedlings were given slow-release (60 days at 20°C) complete

66 Laila M. Karlsson et al. and balanced fertilizer spikes for vegetative growth of pot plants (Blomstra näringspinnar för gröna växter, Cederroth, Upplands Väsby, Sweden), 0, ½, 1 or 2 spikes; 1 spike was recommended dose for the used pot-size (12 cm diameter). In addition, five seedlings were planted in pots with soil intended for sowing (Så-och kaktusjord, Weibulls, Åby, Sweden). Seedlings were watered when needed and allowed to grow for five weeks. Vegetative reproduction Corms were provided from Areka Research Centre, N 07°04'02'', E 37°41'22'', 1785 m a.s.l., and experiments were conducted at Wolaita Sodo University, N 06°50'00'', E 37°45'07'', 1882 m a.s.l. The six released cultivars (Mikias Yeshitila et al., 2011) were included. Corm pre-treatment before burial for multiplication was studied with all cultivars and ‘Zerita’ in addition to investigation of watering after corm burial. Apical meristem was removed and corms were either kept entire, split in two pieces or split in four pieces. All corms were buried in holes dug to 40 cm deep and 50 cm wide, bottom was refilled with 10 cm softened top soil, and the corms were placed thereon and on them 15 L of 50/50% dry cow dung and soil. The corms allocated to watering were irrigated with 5 L per corm every day, when also the area was checked for emergence. Sprouts were harvested and recorded nine months after corm burial (Karlsson et al., 2015). Sprouts (N = 162 [3 corm pre-treatments × 3 original corms × 6 cultivars × 3 replicates]) were replanted within the same area, not adding any additional nutrients, and harvested after one year of growth. RESULTS Seeds and seedlings Seed set Far from all plants observed when flowering set fruits, and some with fruits did not set seeds, while some produced only a few seeds. Recorded seed set per plant with fruits was 0-1,713 seeds from 3-141 fruits on individual plants. There was no obvious relation between plant conditions or environment to seed set, e.g. one large and strong plant in Wonago (N 06°19'27'', E 38°15'45'', 1788 m.a.s.l.) was observed when flowering, not far from other enset, and the owner kept it until seed maturity. The entire harvest was 37 seeds; most fruits were seedless.

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Seed morphology Seed sizes varied between ca. 10 and 20 mm in all directions (length × width × height average [sd] = 16.1 [2.6] × 14.7 [2.0] × 11.0 [1.3]); shapes being irregular. Imbibition occurred mainly through thin channels between the main seed coat and the operculum in the micropyle (Fig. 1). At germination, operculum was pushed out by the expanding root, thereafter the scutellum expanded during several weeks, until all endosperm was distributed to the growing seedling (Karlsson et al., 2013a).

5 mm Scutellum Chalazal (haustorium) 1 mm disk developed from cotyledon First true leaf Embryo Endosperm Channel Apical Operculum/ meristem Micropyle

Fig. 1. Seed morphology (mature seed) of Ensete ventricosum. Photo: L.M. Karlsson. See McGahan (1961), Graven et al. (1996), Puteh et al. (2011) and Karlsson et al. (2013a) for details. Seed germination The first germination occurred after 10 days, most germination was achieved within 14 weeks and the last germination was observed after 24 weeks. Final germination varied from 5 to 55% for the different seed batches, average 24.8%, sd=15.6. There was no positive response to physical or chemical treatments (Karlsson et al., 2013a). Seedling growth After three weeks of growth, there was no correlation between seed size and seedling pseudostem diameter (r2=0.024, p=0.365). After three weeks of growth, there was no significant difference between seedlings with or without manure, but after six months those with manure were significantly larger (Karlsson et al., 2013b). Diammonium phosphate (DAP) fertilizer had no significant positive effect, but mortality increased from 3-4% in local soil, soil with manure or 1-2 g DAP to 30% and 82% with 4 and 8 g of DAP per pot, respectively (Karlsson et al., 2013b). Seedlings planted in the field reached up to 2.67 m pseudostem circumference within 22 months, five plants flowered within 24 months and

68 Laila M. Karlsson et al. had ripe seeds after 36 months. Seedlings grown with one or one half spike (i.e., the recommended dose or half the recommended dose) of balanced fertilizer developed significantly stronger than non-fertilized seedlings regarding number of leaves, leaf area and fresh weight (Table 1, Fig. 2). The pseudostem was wider and larger in those plants given one half and one spike, respectively, compared to non- fertilized plants. Seedlings provided with two fertilizer spikes did not differ significantly from seedlings grown without any fertilization (Table 1, Fig. 2). Table 1. Performance of newly germinated seedlings of Ensete ventricosum grown in ceramic clay pellets without any additional fertilizer compared (t-test) with seedlings provided half, full and double recommended dose slow-release balanced fertilizer for pot plants or fertilized sowing soil. Significant differences indicated with bold, N=5. Factor Recommended Half dose dose Double dose Sowing soil T P T p t p T P Number of leaves 2.558 0.034 3.464 0.008 1.500 0.172 0.000 1.000 Leaf area 3.550 0.008 3.048 0.016 0.657 0.530 1.058 0.321 Pseudostem 4.670 0.002 3.420 0.054 0.764 0.467 0.436 0.674 circumference Pseudostem 2.222 0.057 3.560 0.007 2.034Antal blad0.076 1.582 0.152 16 Antal blad height16 Bladarea 1/10 Fresh weight 4.414 0.003 2.810 0.023 0.952BladareaOmkrets 0.369 på 1/10 pseudostam0.751 0.474 vid avskärningspunkt (cm) Omkrets på pseudostam vid avskärningspunkt (cm) 12 Höjden på där yngsta bladet skiljer sig från pseudostamen (cm) HöjdenMassa påpå avskurendär yngsta växt bladet (g) skiljer sig från pseudostamen (cm) 1612 MassaAntalNumber blad på of avskurenleaves växt (g) ) AntalBladareaLeaf area blad (1/101/10 cm2)

sd 8

BladareaOmkretsPseudostem på1/10 pseudostam vid avskärningspunkt (cm) 128 OmkretsHöjdencircumference på på där pseudostam (cm) yngsta bladet vid avskärningspunktskiljer sig från pseudostamen (cm) (cm) 4 HöjdenMassaPseudostem påpå avskurendär height yngsta (cm) växt bladet (g) skiljer sig från pseudostamen (cm) MassaFresh weight på avskuren (g) växt (g) 84 Black symbols: seedlings grown in 0 fertilized soil intended for germination. 40 0 0.5 1 2 0 0.5 1 2 White symbols: seedlings grown in

Records (see legends, legends, (see Records non-fertilized substrate with added fertilizer sticks for pot plants. 0 0 0.5 1 2 Added fertilizer (No. of sticks)

Fig. 2. Performance of seedlings of Ensete ventricosum when grown at ca. 20°C during five weeks after germination.

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Vegetative reproduction Emergence occurred from all 63 buried corms, emergence of first sprout per corm occurred 50-112 days after burial, during a period with little rain only (Karlsson et al., 2015), thereafter sprouts grew during the rainy season. Emergence for entire corms was later than for split corms and watering decreased average time to emergence. Cultivars differed regarding number of sprouts (from around 35 for ‘Mesena’ to around 100 for ‘Endale’), but splitting increased the number of sprouts (from around 30 for entire to around 80 for quarters) per buried corm (Karlsson et al., 2015); there were totally 4,405 sprouts from 63 corms. Average pseudostem diameter of the seven largest sprouts from all buried corms was 28.7 cm, while the average of all remaining sprouts was about 10 cm; watering gave more equal-sized sprouts (Karlsson et al., 2015). Pseudostem volume of individually planted sprouts after one year of growth was dependent on volume at planting (R2 = 0.37, p < 0.001, Fig. 3).

50

40

30

) one year after planting after year one ) 20

3

10

Volume (dm Volume

0 0 5 10 15 20 Volume (dm3) at sprout planting

Fig. 3. Pseudostem volume of Ensete ventricosum sprouts, calculated from linear records, when replanted after being detached from mother corm and after one year of further growth. Plants were from six different cultivars; a few strongly growing plants were excluded from the graph. Correlation: R2 = 0.42, p < 0.001.

70 Laila M. Karlsson et al.

DISCUSSION Ensete ventricosum plants growing in the wild are generally not utilised as a food source. However, the gene pool of wild plants can be important for development of cultivars (Genet Birmeta et al., 2004) and some people are prepared to accept the unfamiliar food product qualities from these plants (Abraham Bosha et al., 2016). Therefore, requirements for seed set and seed germination (Karlsson et al., 2013a) need to be studied further to make it possible to utilise that gene pool consciously. Growth of seedlings is uncomplicated and efficient by applying manure (Karlsson et al., 2013b), thus seedlings can be used for conventional breeding. However, recommendations for manure application should be supported by systematic studies. It is important not to apply too much chemical fertiliser, because at least young seedlings of enset are sensitive to that (Karlsson et al., 2013b, Fig. 2). Too much manure may harm young seedlings. Increased number of sprouts at multiplication is desired, and one way to achieve that can be to part parent corms in much smaller pieces: the quarters (ca. 0.9 dm3) produced more sprouts and totally larger volume of pseudostem than entire corms (Karlsson et al., 2015). When discussing with farmers, there are some myths on enset cultivation running around, such as "the new shoots must be planted close to house to get smoke", "you cannot grow enset in the field, keep it only in a garden", "you cannot put manure directly on corm, because it will rotten" and "you cannot water on planted corm, since it will rotten". These myths are now falsified. When applying dry cow manure, mixed with soil, directly with corms we got 100% emergence, which is unusual (Mulugeta Diro, 1997). This result may arise from careful corm pre-treatment (the same experienced person split and removed the apical meristem of all corms) and appropriate depth and width of holes for corm burial, including softened topsoil placed under corms and mix of 50/50% dry cow manure and soil directly placed on corm (instead of the common way to place manure on top of soil, claiming it will cause rotting otherwise). It is important to consider indigenous knowledge; farmers have a lot of inherited knowledge on what is functional. However, just because one way functions is not a proof that it is the best way, and farmers' practice should be tested systematically. Our sprouts were considerably larger than expected

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(Karlsson et al., 2015), and farmers who saw them were sure we used some "secret chemical". Rotten corms may be the results of using fresh (not dry) manure directly on corm. In our field, we provided the enset root system with direct access to manure, instead of feeding the weeds on ground surface. Neither the watering gave any rotten corm (Karlsson et al., 2015), instead uniform and healthy sprouts. Of course overwatering can cause problem, which is a truth for all plants. Sprouts from corms parted in smaller pieces emerged sooner, and had more sprouts per corm, which imply that it is better for farmers to part corms into such relatively small pieces. The drawback with that is the survival of the corm if there is risk for prolonged drought, and water access is limited: an entire corm will retain its moisture better than a small piece. Regarding the habit to plant enset directly around houses: after recording of the sprouts, we planted them individually back in the field. The field was far from any house, but still they performed very well. As studied by Tilahun Amede and Mulugeta Diro (2005) enset close to the houses makes it practical to provide household organic wastes and waste water, but otherwise there is no need to plant enset in the vicinity of houses, even though it is understandable and desired to have enset close to houses to improve microclimate. CONCLUSION Our results imply that productivity of enset can be much increased by taking relatively simple measures. Putting effort at corm burial and achieving larger sprouts than currently common is beneficial for the future growth because the plant size depends on sprout size at planting (Fig. 3). For seedlings, fully mature, flowering plants were achieved within two years from germination (Karlsson et al., 2013b). Further studies will contribute with more and more detailed knowledge; as with all crops, there is no end of development. However, already now the most recent knowledge can be compiled and merged to existing enset agricultural advice. For corm burial, we provided a brochure in Amharic (Karlsson et al., 2012). It is important to make sure advisers possess desired level of knowledge about enset agriculture so that they can provide meaningful advice to farmers. ACKNOWLEDGEMENTS We are grateful to Zemach Chelo for assistance and to Marielle Borgestad and Johanna Hultman, Berzeliusskolan, Linköping, for conducting part of

72 Laila M. Karlsson et al. the experiments. Mikias Yeshitila and Areka Research Centre generously shared knowledge and contributed with initial planting material. Wolaita Sodo University provided experimental field. The Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning funded this project within the program Formas-Sida Sustainable Development in Developing Countries. REFERENCES Abraham Bosha, Abitew Lagibo Dalbato, Tamado Tana, Wassu Mohammed, Bizuayehu Tesfaye and Karlsson, L.M. (2016). Nutritional and chemical properties of fermented food of wild and cultivated genotypes of enset (Ensete ventricosum). Food Res. Int. 89: 806–811. Admasu Tsegaye and Struik, P.C. (2001). Enset (Ensete ventricosum (Welw.) Cheesman) kocho yield under different crop establishment methods as compared to yields of other carbohydrate-rich food crops. Neth. J. Agr. Sci. 49: 81–94. Asnaketch Wolde Tensaye, Lindén, B. and Ohlander, L. (1998). Enset farming in Ethiopia. I. Soil nutrient status in Shoa and Sidamo regions. Commun. Soil Sci. Plan. 29: 193–210. Brandt, S.A., Spring, A., Hiebsch, C., McCabe, J.T., Endale Tabogie, Mulugeta Diro, Gizachew Wolde-Michael, Gebre Yntiso, Masayoshi Shigeta and Shiferaw Tesfaye (1997). The “Tree against Hunger”: Enset-Based Agricultural Systems in Ethiopia. American Association for the Advancement of Science, Washington. Cheers, G., Page, S and Olds, M. (Eds.) (2004). Botanica, the Illustrated A-Z of Over 10,000 Garden Plants and How to Cultivate Them. 4th edition. Tandem Verlag GmbH, Potsdam. Genet Birmeta, Nybom, H. and Endashaw Bekele (2004). Distinction between wild and cultivated enset (Ensete ventricosum) gene pools in Ethiopia using RAPD markers. Hereditas 140: 139–148. Graven, P., de Koster, C.G., Boon, J.J. and Bouman, F. (1996). Structure and macromolecular composition of the seed coat of the Musaceae. Ann. Bot. 77: 105– 122. IPCC (2014). Agriculture, forestry and other land use (AFOLU). In: Climate Change 2014: Mitigation of Climate Change, Chapter 11. Cambridge University Press, Cambridge. http://www.ipcc.ch/report/ar5/wg3/ IPNI (International Plant Nutrition Institute) (2013). http://www.ipni.net/publication/nss.nsf/0/66D92CC07C016FA7852579AF00766C BD/$FILE/NSS-17%20Diammonium%20Phosphate.pdf. Karlsson, L.M., Abitew Lagibo Dalbato, Tamado Tana and Mikias Yeshitila (2012). Enset brochures in Amharic and English: http://www.lailakarlsson.se/research.php#drought Karlsson, L.M., Tamado Tana, Abitew Lagibo Dalbato and Mikias Yeshitila (2013a). Seed morphology and germination of Ensete ventricosum (Musaceae). Seed Sci. Technol. 41: 357–370. Karlsson, L.M., Tamado Tana, Abitew Lagibo Dalbato and Mikias Yeshitila (2013b). Early growth and development of Ensete ventricosum (Musaceae) seedlings. J. Plant Sci. 1: 11–17.

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Karlsson, L.M., Abitew Lagibo Dalbato, Tamado Tana and Mikias Yeshitila (2015). Effect of cultivar, traditional corm pre-treatment and watering on sprouting and early growth of Ensete ventricosum suckers. Exp. Agr. 51: 232–243. McGahan, M.W. (1961). Studies on the seed of banana. I. Anatomy of the seed and embryo of Musa balbisiana. Am. J. Bot. 48: 230–238. Mesele Negash and Starr, M. (2015). Biomass and soil carbon stocks of indigenous agroforestry systems on the south-eastern Rift Valley escarpment, Ethiopia. Plant Soil 393: 95–107. Mikias Yeshitila, Zerihun Yemataw, Sadic Muzemil, Abay Ayalew, Fiseha Negash, Kidus Michael, Atnafua Bekele, Abebe Chindi, Fekadu G/Tensay, Dagmawi Melaku and Getachew W/Michael (2011). Registration of enset (Ensete ventricosum (Welw.) Cheesman) varieties Yanbule, Gewada, Endale, Kelisa, Zerita and Mesena. Ethiop. J. Agr. Sci. 21: 142–147. Mohammed, B., Gabel, M. and Karlsson, L.M. (2013). Nutritive values of the drought tolerant food and fodder crop enset. Afr. J. Agr. Res. 8: 2326–2333. Mulugeta Diro (1997). Effect of Propagation Method and Corm Type on Number and Growth of 'Enset' (Ensete ventricosum) Suckers. M.Sc. Thesis, Alemaya University of Agriculture, School of Graduate Studies, Haramaya. Puteh, A.B., Aris, E.M., Sinniah, U.M., Rahman, M.M., Mohamad, R.B. and Abdullah, N.A.P. (2011). Seed anatomy, moisture content and scarification influence on imbibition in wild banana (Musa acuminata Colla) ecotypes. Afr. J. Biotechnol. 10: 14373–14379. Tilahun Amede and Mulugeta Diro (2005). Optimizing soil fertility gradients in the enset (Ensete ventricosum) systems of the Ethiopian highlands: Trade-offs and local innovations. In: Improving Human Welfare and Environmental Conservation by Empowering Farmers to Combat Soil Fertility Degradation, pp. 1–10 (Bationo et al., eds.). African Highlands Initiative Working Papers, No.15.

Ethiop. J. Biol. Sci. 17(Suppl.): 75–101, 2018 © The Biological Society of Ethiopia, 2018 ISSN: 1819-8678 BIOTECHNOLOGICAL STUDIES ON ENSET (ENSETE VENTRICOSUM (WELW.) CHEESMAN)), A FOOD SECURITY STAPLE FOOD CROP OF ETHIOPIA

Genet Birmeta1

ABSTRACT: Several studies relevant for enset improvement and strategic conservation were carried out of which two studies focused on the molecular characterization and one on cultivated enset from nine regions of Ethiopia and the second on five wild enset populations around Bonga area. All the 111 cultivated enset clones were found distinct of each other. In both studies, the genetic diversity among populations was not related to the genetic distances indicating that the current cultivated clones were originated from a limited number of wild progenitors. In addition, the limited gene flow between cultivated and wild enset clones were due to many factors necessitating for ex situ and in situ conservation of wild enset. The third study centered on the development of an efficient micro-propagation protocol for enset that yield up to 75 propagules through wounding the meristem and growing them on modified nutrient medium. Another study developed transformation procedures for enset using both Agrobacterium tumefaciens and particle bombardment as revealed by ß-glucuronidase (Gus) gene expression. A study by the author also revealed identification of endophytes representing 16 bacteria, and 7 yeasts and the profile of cultureable yeasts and lactic acid bacteria from traditionally fermented enset food product, kocho using 16S/26S rDNA sequence analysis. It is interesting to note that Candida ethanolica known to control bacterial wilt and Pantoea agglomerans which infect plants, animals and humans were also identified amongst the microbes using sequence analysis of 16S/26S rDNA. Furthermore, the isolation of the spore forming Bacillus anthrax, the causative agent of anthrax, was critical emphasizing the importance of sanitation and hygiene in enset production, handling and processing. The information generated could be important to develop a starter culture which facilitates fermentation without compromising, kocho quality and the safety of kocho consumers.

Key words/phrases: Enset, Food spoilage, Genetic diversity, Micropropagation, Transformation.

INTRODUCTION Enset (Ensete ventricosum (Welw.) Cheesman) belongs to the family Musaceae (Cheesman, 1947). Morphologically it resembles a banana plant that belong to the related genus Musa, and unlike banana, the edible part of enset is its corm and pseudostem where starch is stored. It grows wild in

1 Institute of Biotechnology, College of Natural and Computational Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia. E-mail: [email protected]; [email protected]

76 Genet Birmeta central, eastern and southern Africa (Baker and Simmonds, 1953), including Congo, Ethiopia, Mozambique, Tanzania, Uganda, and Zambia. However, it is cultivated as a crop only in the highlands of the southern, southwestern and central parts of Ethiopia, where more than twenty million people use it as a staple food. In addition, the whole plant is used for various purposes as animal feed, a source of medicine for humans and cattle, an ornamental, and for making ropes and mattresses out of the fiber. The wild enset (Ensete ventricosum) populations grow mainly around Bonga (Kefficho administrative region) and the distribution is very restricted; to a smaller area around the Omo river (Gamo-Gofa administrative region), and mainly found in areas not disturbed by routine agricultural activities or other forms of human intervention (Gebre Yntiso, 1996) and where it may even be ritually protected (Shack, 1963). In a very sparsely situated it also occurs in other areas like Benshangul-Gumuz. It is regarded as food security crop as it is relatively drought resistant and is available when other crops fail due to drought or other natural calamities (Westphal, 1975). Enset culture is expanding and is being introduced into several regions in Ethiopia, thus promoting the diversification of farming systems for sustainable production (personal observation). Enset makes a very substantial contribution to food security in Ethiopia, but production of enset is low for it depends entirely on unimproved varieties that are maintained through clonal propagation by local farmers. The production may decline as a result of genetic erosion due to drought, bacterial wilt disease and human over-population pressure (Almaz Negash et al., 2002). Although Areka research station, in southern Ethiopia, has been maintaining enset germplasm in field banks since 1987, and with few diversity studies on landraces using farmer-based morphological parameters (Hildebrand, 2001), and genetic variation among cultivated enset clones (Almaz Negash et al., 2002; Genet Birmeta et al., 2002), Dagmawit Tobiaw and Endashaw Bekele (2011) and currently Temesgen Magule et al. (2015), Selamawit Getachew et al. (2014), there is still a dearth of information on its breeding and diversity. This necessitates characterization, maintenance of the existing germplasm in the wild populations, as well as introduction of genes from wild or related species into the cultivated clones to improve e.g. disease resistance and adaptation to enhance future food security of Ethiopia. Future plant improvements in enset, by the use of either conventional plant breeding or modern biotechnological techniques require reliable and

Ethiop. J. Biol. Sci., 17(Suppl.): 75–101, 2018 77 reproducible methods that can differentiate among clones and estimate their genetic relatedness. Genetic diversity, geographical pattern of enset accessions The various studies crucial for the improvement of enset carried out by the author include: i. A study undertaken to describe the extent of genetic diversity in 111 representative samples from nine different enset growing sites in Ethiopia, and to investigate the presence of geographical patterns in this variation. ii. A study to analyze the genetic diversity of wild enset in Ethiopia was carried out to provide information for conservation strategies as well as evidence of possible gene flow between the different gene pools (Genet Birmeta et al., 2004a). iii. Identification of endophytic microbes that are resistant to surface sterilization procedures and antimicrobial drugs during a study on development of in vitro micro-propagation protocol for enset clones (Genet Birmeta et al., 2004b). iv. Development of in vitro propagation protocol for enset clones (Genet Birmeta and Welander, 2004). v. Development of genetic transformation procedures for two enset clones (Genet Birmeta, 2004). vi. Identification of microbes that are involved in spontaneous fermentation of Kocho, a starchy enset food product and to identify those microbes involved in the spoilage of kocho (Genet Birmeta, submitted). In addition to the above other studies that include draft genome sequence data, additional regeneration system for multiplication of clean planting material of Ensete ventricosum, SSR marker system based studies on genetic diversity assessment have been reported by Zerihun Yemataw et al. (2018), Temesgen Magule et al. (2015) and Selamawit Getachew et al. (2014).

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DISCUSSION OF RESULTS i) RAPD analysis to study genetic diversity among clones of Ensete ventricosum in Ethiopia Genetic diversity A RAPD analysis was conducted to characterize 111 individual plants of E. ventricosum cultivated at nine different enset growing sites in Ethiopia (Genet Birmeta et al., 2002). All the 111 clones analyzed were found to be genetically different from each other as shown using different statistical methods (Table 1). The results thus suggest that the different clones existing in Ethiopia could be at least as numerous as the named landraces, or even more since vernacular naming has its limitations. As enset is a multipurpose crop, each farmer generally grows several different clones for different types of food (cooking, bread making, and porridge, for fiber production, for medicinal purposes, as an ornamental etc. Thus, each farmer has his/her own miniature ‘on farm’ germplasm collection, with representation of the most important clones. The comparatively high diversity among enset genotypes observed in our study is in accordance to its outbreeding nature and also its diverse use and selection by farmers, mutations during vegetative propagation, introduction of new genotypes from wild populations and from other farming areas as well as maintenance of even inferior clones for social and cultural reasons (Shigeta, 1996). Table 1. Collection sites for the 111 Ethiopian enset clones, the administrative regions in which they are located, number of collected plants, percentage of polymorphic loci, mean Jaccard’s similarity coefficient and mean Shannon-Weaver gene diversity index (Genet Birmeta et al., 2002). Site Adminstrative No of % Jaccard’s Shannon- region plants polymorphic coefficient Weaver index Answae Arsi 6 78.4 0.69 0.44 Bonga Keffa 20 92.8 0.52 0.53 Chencha Gamo-Gofa 25 87.6 0.58 0.49 Seltae Shewa 8 85.6 0.61 0.49 Setunae Shewa 7 81.5 0.65 0.46 Shonae Kembatana-Haddya 9 88.7 0.64 0.49 Wolkitae Shewa 13 92.8 0.53 0.55 Wondo Sidama 12 88.7 0.83 0.50 Worka Welayta 11 95.9 0.59 0.53 Partitioning of genetic variability The study indicates that most of the genetic variability among enset clones can be attributed to within-site diversity (86%) whereas only a minor part (14%) is detected among sites. Comparatively low diversity was found for sites in the eastern parts of the collection area (Answae and Setunae) whereas sites with high diversity were found in the western parts (Fig. 1).

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Bonga and Chencha in the extreme western and southern parts, respectively, of the enset growing area are the two most similar sites when enset clones are compared, and also appear to be rather different from other sites. Although 120 km apart, these two sites are inhabited by different but related ethnic groups, with a long tradition of ritually protecting wild enset, growing in their area (Shigeta, 1996). Consequently, gene/clonal flow may have taken place between wild and cultivated genotypes. Although part of the explanation for this pattern could be climatic in origin, or depends on the availability of indigenous germplasm, cultural history may also have played a role. The amount of within-site diversity may thus be affected by the degree of importance of this crop in a particular region as well as its livestock accumulation.

Fig. 1. Three-dimensional PCO calculated from RAPD profiles in enset, based on Nei’s genetic distances among 9 collection sites in Ethiopia (Genet Birmeta et al., 2002). Applicability and implications of this investigation The study demonstrated the fact that much of the RAPD variation in enset was found within sites, suggesting that sampling from a few sites only may be sufficient for capturing a large proportion of the genetic variation. However, sampling should nevertheless cover a geographically wide area since there are significant differences in RAPD allele frequencies between sites. In addition, the distribution of RAPD variation may not necessarily reflect the pattern of variation in genes that control important agronomic characters like environmental adaptation. Special consideration should also be given to ethnical history and cultural patterns that may have affected the choice of enset clones grown in different sites.

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ii) Distinction between wild and cultivated enset gene pools in Ethiopia using RAPD markers Forty eight wild enset plants were from five wild population around Bonga area in south-west Ethiopia were used together with eight cultivated and eight Musa samples to analyze the extent of genetic diversity of wild enset using 16S rDNA sequencing.

Fig. 2. A map showing the part of Ethiopia where wild and cultivated enset grows. In the large map, closed circles indicate the five sites at which wild enset populations were collected for this study, while the open squares represent cities. In the small map, the grey area shows the southern administrative zone of Ethiopia where enset cultivation is practiced, the larger black rectangle indicates the area where the wild enset populations were collected, and the smaller black rectangle represents the only other region where wild enset grows in Ethiopia, by the Omo river. Within-population diversity in wild enset populations In southwest Ethiopia, the cultivation area of Ensete ventricosum (enset) overlaps with the natural distribution area of this species. In this study, the extent of diversity was investigated in five wild populations in the Bonga area (Kefficho administrative region) using RAPD. Nine representative cultivated clones and eight Musa samples were included in order to provide information for conservation strategies as well as evidence of possible gene flow between the different gene pools (Genet Birmeta et al., 2004a). Values for within-population diversity were overall rather similar among the wild 5 populations (not shown). These estimators indicated that populations 2 and 3 are somewhat more diverse while especially population 5 was more homogeneous. It is interesting to note that populations 2 and 3 are located in dense forest with little influence by human disturbance while populations 1

Ethiop. J. Biol. Sci., 17(Suppl.): 75–101, 2018 81 and 5 are closer to human settlements and may thus have been influenced by human activities leading to decreased diversity. Partitioning of genetic variation in wild enset The Shannon index attributed most of the total diversity within populations rather than among populations. Among-population differentiation (10%) is quite low when compared with six outcrossing species (15-60%) (Bussel, 1999), and with 18 species (11-88%, and in another review (Nybom and Bartish, 2001). Furthermore, no significant correlation between geographical and genetic distances was observed. Although breeding system is critical, other factors like perennial life form, late successional status and having seeds that disperse by wind or animals (as in the case of enset), are also closely associated with low levels of between-population diversity (Hamrick and Godt, 1989). In our study, the PCA plot (Fig. 3), UPGMA clustering (Fig. 4) and Nei’s genetic distance values indicated low differentiation and suggested that there is considerable gene flow between the five enset populations. Wild enset compared to cultivated enset The wild and cultivated enset samples in this study were genetically distinct from each other as indicated by their considerable differentiation in RAPD profiles and cluster analysis (not shown). PCA plot (Fig. 3) and dendrogram (Fig. 4) also demonstrated a clear separation between the cultivated clones and the wild enset samples, suggesting that cultivated enset may have been introduced into domestication from a limited number of wild enset genotypes in Ethiopia and that subsequent gene flow between the two forms may have been very restricted due to the different modes of propagation (clonal versus outcrossing) and harvesting of cultivated enset prior to flowering.

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Fig. 3. PCA plot based on RAPD polymorphism, with the first two principal components showing phenetic relationships among 48 wild and 9 cultivated enset samples. Origin of the samples is indicated by their symbols. Differentiation between Ensete and Musa Cluster analysis (Fig. 4) showed the eight Musa samples group in accordance with the commonly accepted taxonomy based on morphology and data from molecular markers (Cheesman, 1947; Ude et al., 2002) except for M. nana, which clustered outside of the M. acuminata complex. From our results, it thus appears as if section Eumusa is closer to E. ventricosum than the other sections are. This may facilitate the transfer of genes into enset from well characterized banana germplasm, which mostly belongs to Eumusa.

Endashaw Bekele and Shigeta (2010) based on complete sequence of transcribed spacers and introns from trnT trnF region of chloroplast DNA from thirteen species of Musa and three species of Ensete including the cultivated and wild species of Ensete ventricosum revealed that Musa beccari represent ancestral forms of Ensete and Musa, Ensete gilleti or a species very close to it appears to be the ancestral species of Ensete ventricosum.

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Preservation of genetic resources in enset The distribution of cultivated enset in Ethiopia appears to be expanding. Unharvested mature enset plants in the field and enset products in the fermentation storage pit constitute a household security system, accessible whenever the need arises. However, enset cultivation is currently threatened by bacterial wilt (Xanthomonas musacearum), a very destructive disease in enset and banana. Wild enset as well as Musa species could be important sources of useful resistance genes. In addition, genes for desirable agronomic traits like resistance against other diseases, early maturation, higher nutritional quality and higher productivity would be beneficial for enset improvement. Unfortunately, deforestation due to villagization and construction of major refugee camp sites in the Bonga area, may lead to a decline in genetic diversity in the wild enset germplasm. In addition, disturbance of this environment may also affect wild animals like monkeys that are a primary means of seed dispersal and pollination in wild enset. Furthermore, the monocarpic life form, the absence of gene flow from cultivated enset due to early harvesting, and the recalcitrant nature of seeds could gradually lead to the extinction of wild enset. This calls for adopting strategies for both ex situ and in situ conservation to maintain the existing wild enset in Ethiopia. In vitro multiplication of enset clones (Genet Birmeta and Welander, 2004) and wild enset in combination with traditional propagation methods could be utilized for large-scale multiplication, transportation and introduction of this multi-purpose and sustainable crop to regions with food shortage. The information generated in this study, in combination with our previous study on cultivated enset (Genet Birmeta et al., 2002), can be utilized for strategic sampling, conservation of wild enset and introduction of enset cultivation to other regions with food deficit. The study has also shown that only a small portion of the genetic variation in wild enset is present in cultivated enset clones. Thus, the wild gene pool, which may for example contain genes conferring adaptation for growing at lower altitudes, could be utilized for the improvement of cultivated enset.

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SCI-1 CI

SCI-2

CII SCII- 1 SCII- 2

Fig. 4. Dendrogram based on UPGMA of RAPD profiles, showing phenetic relationships among 48 wild (W, numbers indicate the population and genotype, respectively) enset samples, 9 cultivated (C) enset clones, and 8 Musa accessions (M). Main clusters CI and CII are indicated, as well as sub-clusters SCI-1, SCII-1 and SCII-2 (Genet Birmeta et al., 2002).

Selamawit Getachew et al. (2014) reported transferability of 71 SSR loci from banana (Musa accuminata) to enset using 220 Enset accessions. Among the 71 SSRs tested, 12 (16.9%) were successfully transferable to enset. Eleven (16.9%) of these were used to examine the diversity of the 220 enset accessions that had been collected from eight different zones in Ethiopia. Their results showed that enset diversity was accumulated within

Ethiop. J. Biol. Sci., 17(Suppl.): 75–101, 2018 85 rather than between zones and accessions were not grouped into distinct clusters by zone of collection indicating a high rate of planting material exchange between distant zones. Their result is consistent with our previous studies of diversity of enset (Genet Birmeta et al., 2004a) using RAPDs, and Almaz Negash et al. (2002) using AFLP, Dagmawit Tobiaw and Endashaw Bekele (2011) using ISSR. It is of interest to observe that all markers used resulted to similar trends of conclusions. Temesgen Magule et al. (2015) developed genomic SSR markers for enset and reported a large proportion of these markers to be polymorphic and some were also transferable to related species of the genus Musa. This study also is consistent with the previous study and demonstrated the usefulness of the markers in assessing genetic diversity and structure in enset germplasm, and provides additional potentially useful information for developing conservation and breeding strategies in enset. Zerihun Yemataw et al. (2018) on the other hand reported Genome sequence data from 17 accessions of Ensete ventricosum and presented the first genome-wide sequence with a potential to exploit genetic diversity to generate markers to assist enset selection for key agronomic traits. Harrison et al. (2014) presented a draft genome sequence for enset (Ensete ventricosum). The sequence data of Harrison et al. (2014) suggest a genome size of approximately 547 mega bases for enset which is similar to the 523-megabase genome of the closely related banana (Musa acuminata). They also have reported that at least 1.8% of the annotated M. acuminata genes are not conserved in E. ventricosum with additional note that enset contains genes not present in banana. iii) Identification of bacteria and yeasts from in vitro cultures and from surface sterilized field samples of Ensete ventricosum by rDNA analysis An optimal micropropagation system, for crops like enset with a long life cycle and seeds recalcitrant to germination, is a pre-requisite for the improvement and production of disease-free planting material. Our attempts to establish new cultures from the growing apex situated in the underground corm of enset sprouts repeatedly failed due to microbial contamination. Elimination of endophytic contaminants, in particular from roots, bulbs and rhizomes is more difficult than that from aerial tissues (Kritzinger et al., 1998). The problem of endogenous microbial contamination of cultures is a major bottleneck during micropropagation. The microbes may not be pathogenic in the field but are very destructive under in vitro conditions. These microbes cause growth retardation or death of cultures as a result of overgrowth, competition for nutrients or change of pH and production of

86 Genet Birmeta toxic substances (Leifert et al., 1990). The standard tissue sterilization procedures and addition of antimicrobial drugs did not efficiently control microbial contamination, suggesting the endophytic and antibiotic-resistant nature of the contaminants. The difficulties in decontaminating explants originating from subterranean organs are frequently reported (e.g. Kritzinger et al., 1998). The aim of this study was to identify microbes that are contaminants of enset cultures, and microbes intimately associated with field materials. Identification of the microbes not only facilitates selection of effective and specific antibiotics for future in vitro control of the contaminants, but also indicates possible origins of the contaminants. Bacterial and fungal contaminants of enset (Ensete ventricosum) cultures and microbes associated with surface-sterilized field material were identified by 16S and D1D2 regions of 26S rDNA sequencing for bacteria and yeast, respectively. Complete procedures and methods followed could be obtained from Genet Birmeta et al. (2004b). The identified bacteria showed a high diversity representing 15 species in the 26 isolates investigated (Table 2). Ten bacterial species were identified from in vitro cultures and seven in 10 isolates from field clones. Similarly, three yeast species and one filamentous fungus were identified as in vitro contaminants, whereas five yeast species were isolated from the field material (Table 3). The bacterium, Pseudomonas reactans, and the yeast, Torulaspora delbrueckii, were the most frequent in vitro contaminants. The difficulty in controlling the in vitro contaminants is due to their apparent endogenous nature and their resistance to antimicrobial drugs. Only two bacterial species (Microbacterium paradoxydans and Lactococcus lactis) were found in both in vitro cultures and field materials, with M. paradoxydans representing the most frequent species associated with field tissues. Most of the bacterial species isolated from in vitro enset were Gram- positive and hitherto unrecorded as in vitro contaminants of plant cultures. Our results might therefore provide an indication of some unique characteristics of the enset microflora. The endophytic nature of the bacterial in vitro contaminants has been reported (Kritzinger et al., 1998). In our study, the few cultures that appeared ‘clean’ with no obvious contamination became contaminated when the meristem was wounded during the multiplication stage (results not shown), suggesting that the microorganisms are endogenous.

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Table 2. Bacteria isolated from in vitro and field enset clones using the 16S rDNA sequencing (Genet Birmeta et al., 2004b).

All enset clones were surface-sterilized but only the in vitro isolates were treated with antibacterial/fungal chemicals. The symbol *denotes bacterial species that have been reported as contaminants of in vitro plant cultures in the literature. GB denotes the authors name used when submitting sequence information to NCBI database of microbes. Current knowledge on the pathogens of enset plant is limited. Berhanu Abegaz Gashe (1987) identified Leuconostoc, Pseudomonas, Bacillus, Erwinia spp. and yeasts as causes of spoilage and discoloration of kocho. Pseudomonas spp., Leuconostoc pseudomesenteroides and L. citreum isolates identified in the present study might also involve in this process. Likewise, discoloration of enset food products is a common problem during storage, suggesting that P. putida and P. reactans could possibly be pathogens. The microfungal/yeast flora was less diverse than the bacteria. This was also observed during another study. Eight different yeast species were identified among the 25 isolates in comparison to 15 bacteria species from the 26 bacterial isolates (Table 2, Table 3). As enset is a genetically diverse crop, the high diversity of its microbial flora, is anticipated to be more pronounced than recorded here. Surface- sterilization and antibiotic treatments exclude a substantial number of microorganisms from being isolated. However, as the identified microorganisms impair micro-propagation of enset, they have the highest importance in the frame of the current efforts to develop in vitro regeneration systems for future improvement and supply of disease-free enset planting material for cultivation. Many of the bacteria identified are directly or indirectly related to compost, or have human or animal origins

88 Genet Birmeta and might have been introduced due to traditional cattle-based agriculture and use of animal manure as compost. Our results suggest the need to transfer field plants to a glasshouse prior to introduction of explants to in vitro growth in order to reduce epiphytic microbes. Careful selection and incorporation of specific antibiotics in the culture medium are essential to eradicate endophytic microbes of animal and/or human origin. The identification of the contaminants will facilitate the selection of appropriate antibiotics for their prevention. Table 3. Yeasts isolated from in vitro and field enset clones using D1D2 regions of 26S rDNA sequencing (Genet Birmeta et al., 2004b).

GB denotes the authors name when submitting sequence information to NCBI database of microbes.

iv) Efficient micropropagation protocol for Ensete ventricosum clones through meristem wounding. A three step procedure An efficient and optimum in vitro propagation system is crucial for the improvement of enset clones. To date, very few tissue culture studies have been reported for enset. Taye Bezuneh (1984), Afza et al. (1996), Almaz Negash et al. (2000) and Tesfaye Zeweldu and Ladders (1998) attempted to develop initiating in vitro regeneration of enset with very little success for large-scale micropropagation and they emphasized the major problems with growing and multiplying enset in vitro. In our study, an efficient three-step protocol for in vitro propagation of Ensete ventricosum (enset) was developed that consisted of initiation, bud proliferation, and shoot elongation and rooting stages. Wounding the meristem region and dividing the corm tissue to induce sprout formation in the field, a traditional enset propagation practiced by local farmers in Ethiopia was also adopted in this work. Furthermore, since plant nutrient requirements vary at different growth stages under natural conditions, the three micropropagation steps that we adopted in our investigation ensured the formulation of different media components depending on the growth

Ethiop. J. Biol. Sci., 17(Suppl.): 75–101, 2018 89 stage of the cultures. The proportion of macronutrients is adjusted according to nutrient uptake observed in glasshouse-grown enset plants (Table 4). Detail procedures could be obtained from Genet Birmeta and Welander (2004). Table 4. The ranges and average mineral contents in leaf tissue of sprouts of 24 clones of Ensete ventricosum grown in the glasshouse in comparison to essential nutrients considered adequate for higher plants in general. Information on higher plants adapted from Stout et al. (1951) (NI no information available) (Genet Birmeta et al., 2004c).

The main problems in enset culture initiation are phenol exudation and endophytic bacteria contamination. Afza et al. (1996) and Tesfaye Zeweldu and Ladders (1998) have also reported phenol exudation to be a major constraint in enset tissue culture in particular in many other tropical plants. Polyphenol exudation is exaggerated in response to wounding and high iron concentration, a problem which hinder shoots to elongate. The problem of phenol was overcome by adding 0.5–1% (w/v) activated charcoal together with dark incubation of the cultures. In addition, persistent endophytic bacterial infection inhibited in vitro growth resulting in the loss of some clones. This problem promoted another study which identified contaminants of enset cultures, which were resistant to various antimicrobial agents, (including some possible pathogens) and yeasts using rDNA sequencing (Genet Birmeta et al., 2004b). Shoot-tip necrosis, which is another constraint in enset micropropagation, caused by a shortage of calcium in the medium (for example, Mathew and Philip, 1996) was minimized by replacing calcium chloride with calcium gluconate monohydrate. Reducing ammonium content in the medium is one way of reducing toxicity. The procedure developed provided a high propagation rate in spite of the various problems encountered (Fig. 5). In the protocol, more than 75 shoots were produced from a single wounded shoot tip, indicating the efficiency of this protocol. From an initial 12 shoots, clone Feresae produced 900 shoots in one subculture, indicating the potential of this clone for the production of

90 Genet Birmeta high number of shoots. The large differences in multiplication capacity observed between the different clones may be an indication of the specificity of different clones with respect to nutrient requirements. Differences in multiplication rate among clones have also been observed for banana and plantain (Vuylsteke, 1985). This protocol can be further optimized for other enset clones.

Fig. 5. a–i Micropropagation of Ensete ventricosum. a) Conical shaped shoots formed on initiation medium after 2 weeks, b) unwounded shoot with two adventitious shoots at the base, c) multiple buds formed on modified MS medium (EV-2MS) after 5 weeks on bud proliferation medium, d) multiple shoots formed on a small piece of corm tissue as seen with the scanning electron micrograph, e) light microscopy section showing corm. Arrow indicates an internal shoot meristem, f) multiple shoots formed on corm tissue in EV-MS medium, after 6 weeks, in elongation and rooting medium, g) multiple shoots formed on corm tissue in MS after 6 weeks in elongation and rooting medium, h) roots with well- developed secondary roots in elongation and rooting medium, i) plantlets after acclimatization in the glasshouse for 6 weeks. Bars: 1 cm (a–c, f–h); 0.3 mm (d,e); 3 cm (i). (Genet Birmeta and Welander, 2004). Following our report, Mulugeta Diro et al. (2004) also reported that wounding the apical dome by splitting appears necessary to release lateral buds from apical dominance of the tip of the monopodial corm of enset during micropropagation. The greater response in production of multiple

Ethiop. J. Biol. Sci., 17(Suppl.): 75–101, 2018 91 shoots by zygotic seedlings cultured in vitro could be due to the absence of blackening and the juvenile nature of the explants. Recently, Tripathi et al. (2017) reported micropropagation system for enset cultivar ‘Bedadeti’ using corm discs containing intercalary meristems. The schematic flow diagram of Tripathi et al. (2017) showing various steps of regeneration of complete plants takes over twenty months while Genet Birmeta and Welander (2004) reported 75 shoots from corm tissues in 14 weeks while Tripathi et al. (2017) obtained only 36 complete plantlets per corm disc and with over extended time of twenty weeks. Although the number of plantlets could differ depending on the clones of enset used, the extended time observed from Tripathi et al. (2017) work needs further improvement. v) Gus expression in the monocot crop Ensete ventricosum through particle bombardment and Agrobacterium transformation Enset has a very long regeneration time ranging between 9 and 14 years depending on the clone and altitude at which it is grown. Due to the long regeneration time and recalcitrant seed to germination, improvement of enset through conventional plant breeding appears to be less viable. Although enset is known to have desirable traits such as high productivity, it has some drawbacks that require improvement to maintain the sustainability of the crop. For instance, enset is a simple basic starch crop, quite low in protein, and vitamin A, and is attacked by some destructive diseases such as bacterial wilt and fungal diseases like Mycosphaerella musicola and Sclerotium rolfsi (Quimio and Mesfin Tessera, 1996). Improvement of these traits in important enset clones could be achieved through modern biotechnological technique such as genetic transformation. Hence, development of transformation procedures for the improvement of these agronomically desirable traits in enset is essential. In this study, a transformation procedure for enset was developed through both Agrobacterium and particle bombardment techniques as confirmed by gus gene expression (Genet Birmeta, 2004; Genet Birmeta et al., 2004c). All explant types used such as shoot tips, leaves, roots and zygotic embryos showed gus expression (Fig. 6). Agrobacterium-mediated transformation showed a higher percentage of GUS positive shoot tip (63%) and leaf (50%) explants in clone Erba, when the explants were sonicated prior to transformation. Our results indicate that the expression of gus gene is affected by sonication treatment, plasmid size, co-cultivation period and transformation methods. This study proved enset although a monocot crop could be infected by Agrobacterium tumefaciens. The transformation

92 Genet Birmeta procedure developed in this work could provide the basis to further optimize the procedures and develop clones with improved agronomic traits such as disease resistance.

Fig. 6. Transient GUS expression detected after Agrobacterium and particle bombardment transformation experiments in the different Ensete ventricosum tissues. Fig a) shoot tip, b) leaves, c) root piece, d) zygotic embryo and e) transverse section of zygotic embryo. A, c, d and e after Agrobacterium infection and, b after particle bombardment. Bars denote 1 cm. (Genet Birmeta et al., 2004c). vi) Yeasts and bacteria associated with kocho, an Ethiopian fermented food from Ensete ventricosum Kocho, a traditionally fermented staple enset food is a food security crop as its food could be stored for a long period and is available whenever needed and when other crops fail. However, kocho quality, such as taste, colour (discoloration), texture, aroma (off-flavour), and its nutrition is often compromised due to the action of microbes in particular when they proliferate under favourable conditions. However, current knowledge on microbes involved in kocho fermentation and putative pathogens to humans is very limited. A microbial study was conducted on kocho to investigate the dynamics of the microbes across three fermentation stages to identify kocho spoilage microbes. The isolates were identified by sequencing the ITS and/or D1D2 26S rDNA and 16S rDNA regions for yeasts and bacteria respectively. Thirty one different endophytic, culturable yeasts, Lactic Acid Bacteria (LAB) and total aerobic bacteria were identified. Most of the microbes were known to involve in beneficial and harmful activities such as fermentation, contamination, food spoilage, pathogenicity. The identification of the strains responsible for spoilage can lead to information

Ethiop. J. Biol. Sci., 17(Suppl.): 75–101, 2018 93 that can help to eliminate the kocho spoilage microbes. Development of starter cultures using selected microbes facilitates fermentation in more predictable way, increase the nutritional value, and prevent the growth of unwanted (pathogenic) organisms and food spoilage. This is in accordance with the recent findings by the author (Genet Birmeta et al., 2018). Yeasts associated with kocho The yeasts predominantly isolated from 2 to 5 days (fresh), 3 to 4 months (mid-term fermented) and 7 to 12 months (long-term fermented) kocho are Issatchenkia scutulata var. exigua (25%), Geotrichum silvicola (36%), and Candida silvae (75%), respectively. Many of the yeasts identified including the three yeasts are involved in fermentation. The yeast Geotrichum silvicola was isolated across all the three fermentation periods, although it is less dominant in the long term fermented kocho. The study illustrated that the dynamics of yeasts and bacteria through time was different. The dominancy of yeasts decreases from fresh fermented to long-term fermented kocho, while the bacterial population in particular LAB was shown to increase with time (this trend was also observed in a previous study carried out by the author (Genet Birmeta et al., 2004b). Lactic Acid Bacteria (LAB) associated with kocho LABs are involved in fermentation, acid production and are often used as preservatives and may kill or avoid unwanted microorganisms including kocho spoilage organisms. LAB the most predominantly isolated from fresh, mid-term and long-term fermented kocho are Lactobacillus plantarum (95%), Lactobacillus plantarum (95%) and Acetobacter pasteurianus (42%), respectively. Lactobacillus plantarum was dominant and was isolated throughout all the fermentation stages. Similarly, Leuconostoc mesenteroides, Leuconostoc pseudomesenteroides were isolated from mid- term and long-term fermented kocho. In a previous study by the author, Leuconostoc mesenteroides was identified from in vitro enset material (Genet Birmeta et al., 2004b). Lactobacillus, Pediococcus and Leuconostoc species) are the major lactic acid bacteria in kocho, and in Eragrostis tef, an indigenous Ethiopian crop (Ayele Nigatu, 2000). L. plantarum isolated consistently in this study and L. pseudomesenteroides are known to have antimicrobial activity. Similarly, acetic acid producing bacteria, Acetobacter pasteurianus and Acetobacter cerevisiae which produce acetic acid were frequently isolated from long-term fermented kocho. When oxygen level is high, the production of acetic is increased leading for the inhibition of yeasts and moulds (Weinberg et al., 1993). The undissociated acids lactic acid,

94 Genet Birmeta acetic acid and propionic acid are known to inhibit growth of yeast (O’Kiely and Muck, 1992). Lactic acid fermentation of food has been found to reduce the risk of having pathogenic microorganisms grow in the food (Campbell, 1987). Production of bacteriocins by lactobacilli also reported to hinder the colonizing and competitive ability of many microbes (Hammes and Tichaczek, 1994). Aguirre and Collins (1993) pointed out LABs are safe for human consumption due to their common occurrence in foods and feeds together with their long-lived use which contributes to their natural acceptance as GRAS (Generally Recognized As Safe) for human consumption. Hence, the findings suggest enset fermentation in general by lactic acid bacteria such as L. plantarum and acetic bacteria such as Acetobacter may be safe practice and prevents kocho spoilage. Kocho fermentation Fermentation involving microbes is an ancient process ever known in Biotechnology. Fermentation process involves ethanol production by yeasts or organic acids by lactic acid bacteria through the action of their enzymes (Campbell, 1987). In traditional fermentation, fresh kocho contains a mixed microflora which starts fermentation (Abraham Bosha et al., 2016), and the microbes come from the raw material (Campbell, 1987). Many of the yeasts identified in this study have fermentative activity. Candida silvae (75%) and Pichia jadinii (17%) are isolated from long-term fermented kocho. Candida and Pichia spp. survive acidic condition created by LABs, as a result they were the only yeasts isolated from long-term fermented kocho. Candida sp. is lactate-utilizing genera and thrives under aerobic condition (Persson, 2015). During kocho fermentation, the practice of opening the pit regularly for mixing the kocho mass allows partial aerobic condition for microbes to thrive and consequently causing kocho spoilage. In addition, the fermentation of kocho, involving yeasts and LABs, has a major influence on the nutritional and food quality of enset food products (Abraham Bosha et al., 2016). LABs isolated frequently are L. plantarum and Acetobacter sp. suggesting their role in kocho fermentation. Modern methods of gene-technology make it possible to design and develop starter cultures with specific qualities. The information generated here are relevant to develop a defined starter culture which facilitates kocho fermentation without compromising kocho quality and the safety of kocho consumers. Hence, more research is needed on candidate microbes. Modern methods of gene-technology make it possible to design and develop starter cultures with specific qualities.

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Food spoilage Foods are considered habitats for microorganisms. Most foods susceptible for yeast spoilage have low pH (5.0 or lower) which restricts the growth of competing bacteria and high sugar and organic acid content for easily metabolized carbon sources (Loureiro and Malfeito, 2003; Crawford, 2014). Kocho as traditional and spontaneously fermented food, is susceptible to spoilage, as it has favourable conditions for yeast growth such as low moisture, low pH range of 3-5, high concentration of soluble carbohydrates. Kocho, once removed from fermentation pits, becomes easily contaminated and spoilt by micro-organisms. In silage, the concentration of moulds and yeasts was found to be the major factor starting deterioration when it is exposed to air (Woolford, 1990). During fermentation and storage, if the population of yeast, using lactate as substrate exceed a certain level (105 cfu/g DM in silage), it is more likely that food product gets deteriorated (Jonsson and Pahlow, 1984). Microbes involved in fermentation also affect the nutritional quality of foods. Ohyama et al. (1975) indicated that aerobic deterioration of silage leads to a lower nutritional value due to the risk of proliferating deteriorating micro-organisms. Pichia fermetans, Pichia membranifaciens and Pichia jadini (5 Pichia species isolated) and Issatchenkia scutulata identified in this study and many Candida sp., though fermentative yeasts, are recorded as frequent contaminants and food spoilage yeasts (Crawford, 2014) as they may proliferate under low pH produced by LAB which is inhibitory for most yeasts. Crawford (2014) also added that some strains of Pichia and Candida species produce zymocins, a yeast killer toxin, in agreement to the absence of other yeasts in long-term fermented kocho in this study. Pichia jadinii survived the acidic condition as it can utilize lactic acid as substrate. Thus the proliferation of P. jadini, in the long-term fermented kocho, under favourable condition may lead to kocho spoilage if it exceeds the set limit. In silage under aerobic condition and during inappropriate storage the dominating yeast genera are the lactate-assimilating Candida and Pichia sp. (Jonsson and Pahlow, 1984). This is in agreement with the study as in the long term fermented kocho, the yeasts Candida sp. and Pichia sp. are the only yeast species isolated. Oxygen availability appears to be a key parameter that influences spoilage of food caused by fermentative yeasts. Use of air tight sealed, oxygen-resistant packaging in particular during storage may minimize food spoilage as many yeasts and some bacteria proliferate in aerobic conditions.

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Deak (2007) argued that compared with bacteria and molds, yeasts play a minor role in food spoilage. Berhanu Abegaz Gashe (1987) using a study of physiological characterization, identified bacteria such as Leuconostoc, Pseudomonas, Bacillus, Erwinia spp. isolated from slimy kocho samples and yeasts as causes of spoilage and discoloration of enset food products. In a previous study, the author has identified the bacterium, Pseudomonas reactans, and the yeast, Torulaspora delbrueckii, as the most frequent in vitro contaminants of enset cultures (Genet Birmeta et al., 2004b). T. delbruecki is recorded as food contaminant microbe. The numbers of bacteria in food can increase rapidly and soon become hazardous to health, particularly if the food has a favourable temperature and water content. Meskerem Elfu (2018) studied eight lactic acid producing bacteria isolated as potential starter culture organisms for enset fermentation preparation that would reduce fermentation time. Harmful microbes associated with kocho With regard to hygienic and health aspects, the study identified many microbes among others Candida sp., C. silvae and Geotrichum silvicola which are reported to be opportunistic or obligate pathogens. The observed dominance of spore forming bacteria of the genus Bacillus (3 species isolated), in particular Bacillus anthracis isolated from total aerobic bacterial medium is of critical health concern. Similarly, the bacteria Pantoea agglomerans (38%), isolated from total aerobic bacteria selective medium is reported to infect plants, animals and humans (Dutkiewicz et al., 2016). It is worth noting that enset based agriculture is a mixed agriculture which heavily relies on cattle manure as compost which may lead to introduction of pathogens from cattle. The study supports the significance of research around food-borne diseases as priority agenda. The study emphasises the paramount importance of sanitation and hygiene in enset production, handling and processing of enset and its food products. Beneficial microbes associated with kocho Many microbes such as Candida ethanolica are reported to have inhibitory or biocontrol activity, including against bacterial wilt. Some of the yeasts and LAB such as L. plantarum and L. pseudomesenteroides have antimicrobial activity which may be important to control the growth of unwanted food spoilage microbes and pathogens. Biotechnological and microbial research to unravel their potential as biocontrol agent including against unwanted food (kocho) spoilage organisms has crucial importance in eco-friendly and sustainable manner. Similarly, some of the organisms

Ethiop. J. Biol. Sci., 17(Suppl.): 75–101, 2018 97 identified are reported to have importance in biofertilizer (Bacillus simplex, Candida ethanolica, Lactobacillus buchneri), biogas (Candida ethanolica) production and thus more research should be geared towards unraveling their potential. CONCLUSION AND RECOMMENDATIONS The outcomes of these investigations will contribute towards improving the livelihood of the peasant households, ensure the sustainability of the crop and benefit the country at large. Future research efforts should be directed to the following areas:  Wide-scale efforts on natural resource preservation and maintenance of the existing domesticated and wild enset germplasm in Ethiopia.  Increasing the content of proteins and vitamin A in the plant to ensure the livelihood and health of peasant households.  Investigation of enset bacterial diseases and food spoilage microbes, food-borne diseases, pathogenicity testing of some of the microbes recorded by the author and other researchers and other putative diseases.  Awareness creation among farmers on the importance of sanitation and hygiene in enset production and processing.  Further investigations on the potential of enset as medicinal plant, fiber, starch and ornamental.  Development of a predictable starter culture and upgrading traditional fermentation of kocho to industrial level.  Strengthening research to unravel the potential biotechnological uses of enset microbes as biocontrol, biofertilizer and biogas. ACKNOWLEDGEMENTS My thanks goes to BIOEARN and SIDA/SAREC for funding my studies and PhD work. I also acknowledge the grant provided by IFS. I would like to thank Department of Microbiology, Swedish University of Agriculture Science University, Uppsala, Sweden, for allowing me to use their laboratory facilities. I thank all who supported me during material collection for the various studies.

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Microbiol. 86: 23–50. Mathew, M.M. and Philip, V.J. (1996). Clonal propagation of Enset ( (Roxb.). Cheesman) through shoot tip cultures. Plant Cell Rep. 16: 232–234. Meskerem Elfu (2018). Isolation and characterization of starter culture bacteria for Ensete ventricosum fermentation isolation and characterization of starter culture bacteria for Ensete ventricosum fermentation. Arch. Med. Biotechnol. 1:2 Mulugeta Diro, van Staden J. and Bornman C.H. (2004). Propagation of Ensete in vitro: a review. S. Afr. J. Bot. 70: 497–501. Nybom, H. and Bartish, I. (2001). Effects of life history traits and sampling strategies on genetic diversity estimates obtained with RAPD markers in plants. Persp. Plant Ecol. Evol. Syst. 2/3: 93–114. Ohyama, Y., Masaki, S. and Hara, S.I. (1975). Factors influencing aerobic deterioration of silages and changes in chemical composition after opening silos. J. Sci. Food Agri. 26(8): 1137–1147. O’Kiely, P. and Muck, R.E. (1992). Aerobic deterioration of lucerne (Medicago sativa) and maize (Zea mays) silages—Effects of yeasts. J. Sci. Food Agri. 59(2): 139–144. Persson, A. (2015). Yeast in Forage Crops and Silage Aerobic Stability at 15 Swedish Dairy Farms. M.Sc. Thesis, Swedish University of Agricultural Sciences, Uppsala, Sweden. Quimio, A.J. and Mesfin Tessera (1996). Diseases of enset. In: Enset-Based Sustainable Agriculture in Ethiopia. pp 188–203 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebre-Mariam, eds.). Proceedings from the International Workshop on Enset held in Addis Ababa, Institute of Agricultural Research, Addis Ababa. Selamawit Getachew, Firew Mekbib, Belayneh Admassu, Segenet Kelemu, Sisay Kidane, Kefyalew Negisho, Djikeng, A. and Nzuki, I. (2014). A look into genetic diversity of enset (Ensete ventricosum (Welw.) Cheesman) using transferable microsatellite sequences of banana in Ethiopia. J. Crop Improv. 28: 159–183. Shack, W.A. (1963). Some aspects of ecology and social structure in the enset complex in the south-west of Ethiopia. J. Royal Anthropol. Inst. 93: 72–79. Shigeta, M., (1996). Creating landrace diversity: The case of the Ari people and enset (Ensete ventricosum) in Ethiopia. In: Redefining Nature, pp. 233–268 (Ellen, R. and Fukui, K., eds.). Ecology, Culture and Domestication, Cornwall. Stout, P.R., Meager, W.R., Pearson, G.A. and Johnson, C.M. (1951). Molybdenum nutrition of crop plants. I. The influence of phosphate and sulfate on the absorption of molybdenum from soil and solution cultures. Plant Soil 3: 51–87. Taye Bezuneh (1984). Evaluation of some Ensete ventricosum clones for food yield with emphasis on the effect of length of fermentation on carbohydrate and calcium content. Trop. Agr. (Trinidad) 61: 111–116. Temesgen Magule, Bizuayehu Tesfaye, Mario, A., Mario, E. and Marcello, C. (2015). Development of SSR markers and genetic diversity analysis in enset (Ensete ventricosum (Welw.) Cheesman), an orphan food security crop from Southern Ethiopia. BMC Genetics 16: 98. doi:10.1186/s12863-015-0250-8 Tesfaye Zeweldu and Ladders, P. (1998). Preliminary tissue culture investigation in Ensete (Ensete spp.). Angew. Bot. 72: 25–27. Tripathi, L., Matheka, J., Merga, I, Gebre, E. And Tripathi, J. (2017) Efficient regeneration system for the rapid multiplication of clean planting material of Ensete ventricosum (Welw.) Cheesman. In Vitro Cell. Dev. Biol. Plant 53: 624–630. Ude, G., Pillay, M., Nwakanma, D. and Tenkouano, A. (2002). Analysis of genetic

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diversity and sectional relationships in Musa using AFLP markers. Theor. Appl. Genet. 104: 1239–1245. Vuylsteke, D. (1985). Feasibility of in vitro propagation of bananas and plantains. Trop. Agr. 62: 323–328. Weinberg, Z.G., Ashbell, G., Hen, Y. and Azrieli, A. (1993). The effect of applying lactic acid bacteria at ensiling on the aerobic stability of silages. J. Appl. Bacteriol. 75(6): 512–518. Westphal, E. (1975). Agricultural System in Ethiopia. Centre for Agricultural Publishing and Documentation, Agricultural University, Wageningen. Woolford, M.K. (1990). The detrimental effects of air on silage. J. Appl. Bacteriol. 68(2): 101–116. Zerihun Yemataw, Sadik Muzemil, Daniel Ambachew, Tripathi, L., Kassahun Tesfaye, Alemayheu Chala, Farbos, A., O’Neill, P., Moore, K., Grant, M. and Studholmeg, D.J. (2018). Genome sequence data from 17 accessions of Ensete ventricosum, a staple food crop for millions in Ethiopia. Data Brief 18: 285–293. doi: 10.1016/j.dib.2018.03.026. https://www.ncbi.nlm.nih.gov/pubmed/29896517

Ethiop. J. Biol. Sci. 17(Suppl.): 103–119, 2018 © The Biological Society of Ethiopia, 2018 ISSN: 1819-8678 STATUS AND FUTURE PROSPECTS OF RESEARCH ON DISEASES OF ENSET (ENSETE VENTRICOSUM) AND THEIR MANAGEMENT

Adane Abraham1

ABSTRACT: The production of enset in Ethiopia is limited by a number of constraints of which diseases play a major role. The most important disease is bacterial wilt (BW) caused by Xanthomonas campestris pv. musacearum. Cultural practices such as crop sanitation, avoiding the use of contaminated tools and destruction of infected plants are commonly used to manage BW. Since these practices do not offer adequate or complete BW control, research efforts have been made to develop BW resistant enset varieties. However, no success was registered as all enset clones evaluated did not have adequate level of resistance. Currently, efforts are being made to introduce transgenic resistance and bio-intensive integrated disease management options. Enset is also affected by many other diseases of lesser economic importance caused by fungi, nematodes and viruses. Fungal foliar diseases include leaf spot diseases caused by Phyllostica sp., Pyricularia sp., or Drechslera sp. which commonly affect suckers, seedlings and young plants. Leaf spot diseases in older plants are caused by Cladosporium sp., Deightoniella sp. or Mycosphaerella musicola. Wilt and root rot caused by Sclerotium rolfsii or Fusarium oxysporum are also encountered but rare. In general however, fungal diseases are of minor economic importance as adult enset plants tolerate them. Among the common parasitic nematodes that attack enset are the root lesion nematode caused by Pratylenchus goodeyi, the root knot nematode caused by Meloidogyne spp. and the leaf nematode caused by Aphelechoides ensete. Survey of enset nematodes indicated that Pratylenchus goodeyi was the most prevalent followed by A. ensete and Meloidogyne spp. Finally, a new virus with bacilliform particles causing chlorotic streak and severe stunting of enset has been described. The virus tentatively named Enset leaf streak virus has a double stranded DNA genome of 7163 base pairs and belongs to genus Badnavirus, family Caulimoviridae. No other virus including Banana streak OL virus reported from banana in Ethiopia have yet been reported on enset. A nationally coordinated effort assisted by further research should be made to develop integrated management strategies for enset BW by using traditional and new technologies. At the same time, the incidence and extent of damage caused by the other enset diseases should be quantified, and the diseases be prioritized and management options developed before their re-emergence as major threat to enset production due to factors such as climate change.

Key words/phrases: Bacterial wilt, Disease management, Fungi, Nematodes, Viruses.

1 Department of Biotechnology, College of Biological and Chemical Engineering, Addis Ababa Science and Technology University, Addis Ababa, Ethiopia. E-mail: [email protected]

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INTRODUCTION Enset (Ensete ventricosum) serves as a staple or a co-staple food crop for about 20 million people in southern Ethiopia. The edible parts of the plant are the pseudostem and underground stem (corm) which are mainly pulverized and fermented into a starch-rich products locally called kocho and bulla. In addition, the corm can be harvested at almost any stage of the crop, and cooked and consumed as amicho in the same way with other root and tuber crops, relieving hunger during periods of critical food shortages. In 2013, it was estimated that over 67 million enset trees were harvested from which 15,924,733, 18,604,186.61 and 679,527 quintals of amicho, kocho and bulla, respectively, were expected to be produced from private peasant holdings (CSA, 2013). Enset is also known for its high productivity and its tolerance to drought. Hence it is considered as one of the priority crops for food security in the country (Fikre Handaro et al., 2012). However, the crop faces a number of biotic and abiotic constraints that limit its production. Biotic constraints include diseases caused by bacteria, viruses, nematodes and fungi; insects such as mealy bugs, aphids, jassids and vertebrate pests including mole rats, porcupines, monkeys and wild pigs. Among the major abiotic factors affecting enset production are drought and poor soil fertility. Of all these factors, diseases collectively are known to be one of the most important constraints and thus attracted major research attention in the past. The pathogens that cause these diseases vary in the amount of damage they cause with some causing extreme damage and killing the plants while others have minor or no significant economic effects. Table 1 summarizes enset diseases so far recorded in Ethiopia, the associated pathogens and their current economic importance at national level. In the remaining part of this paper, research results on the diseases of enset caused by different group of pathogens and their management are presented.

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Table 1. Enset diseases and associated pathogens reported in Ethiopia. Disease Pathogen(s) Economic importance

Bacterial Wilt Xanthomonas campestris. musacearum Major

Corm rot Unidentified bacteria suspected Minor

Leaf nematodes Aphlencoides ensete, A. sp. Moderate

Root lesion nematodes Pratylenchus goodeyii, P. zeae,., Moderate Trichodorus spp, Helicotlybchus spp., etc.

Root knot nematodes Melodogyne spp Minor

Virus- leaf streak and Enset leaf streak virus Moderate mosaic

Fungal leaf spot Mycosphaerella musicola, Phyllosticta Minor spp., Pyricularia spp., Drechslera spp., Cephalosporium spp. ,Deightoniella sp. Phoma spp., Selenophoma spp., Septoria spp., Thielaviopsis spp. Cylindrocladium quinqueseplatum

Fungal root rot/wilt Sclerotium rolfsii Minor Fusarium oxysporum

CURRENT STATUS AND FUTURE PROSPECTS OF ENSET DISEASES Bacterial diseases Bacterial wilt (BW) caused by Xanthomonas campestris pv. musacearum is by far the most economically important disease of enset. A lethal wilt of enset in Ethiopia presumed to be the first report of the disease was first recognized by Castellani (1939), who reported it as threatening enset production. It was also stated in the report that the disease is similar to Moko bacterial wilt and that it could be transmitted from enset to banana, with a slower disease development (Castellani, 1939). However, the description of the causal agent of the disease as bacterial was described 30 years later by Dagnachew Yirgou and Bradbury (1968) who coined the name Xanthomonas musacearum to the pathogen. The same pathogen was later isolated from banana with similar wilt symptoms in the enset-growing region of southwest Ethiopia (Dagnachew Yirgou and Bradbury, 1974). These authors recommended that great care should be taken to minimize the spread of the wilt to banana in Ethiopia and other parts of the world where it could pose a serious problem. The disease nevertheless was later reported on banana in Uganda in 2001 (Tushemereirwe et al., 2004) where it rapidly became a serious threat to its production later spreading to many other banana growing countries in Eastern Africa (Tripathi et al., 2009).

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Since the recognition of the bacterial nature of enset wilt disease in Ethiopia, considerable research efforts have been made to further understand the pathogen and disease epidemiology in order to develop management options. Similar efforts were made during the last decade in other countries growing banana, particularly in Eastern Africa where the disease was considered a major production constraint. The main research achievements on bacterial wilt disease of enset or banana over the last decades can be summarized as follows: 1. The geographical distribution of the disease in enset and banana growing areas of Ethiopia and banana growing areas elsewhere was determined through repeated surveys. In Ethiopia, it is now established that the disease occurs in all enset growing areas although the incidence and severity varies among locations and years. 2. The causal bacteria have been characterized in detail using morphological, biochemical physiological and molecular tools. These included pathogenicity and hypersensitivity tests in various plant hosts, studies on pathogen variability in space and time and nucleotide sequencing of whole genome of Xanthomonas campestris pv musacearum in laboratories abroad. 3. Main methods of the natural spread of the disease and means of pathogen survival have been established for enset in Ethiopia and banana elsewhere, although there is a knowledge gap on biological vectors of BW pathogen. Such information has been the basis for the sanitation-based control measures adopted to check BW disease on the two crops. 4. Reliable diagnostic methods have been developed to efficiently detect and identify the pathogen. The most recent developments in this area include development and use of semi-selective media, antibody-based tests including Enzyme-linked immunosorbent assay and fast lateral flow devices that are made commercially available, and PCR-based protocols. 5. Evaluation of various enset clones for genetic resistance from enset have been conducted and promising results were obtained. In addition, efforts are being made to develop transgenic enset varieties with BW resistance.

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Prevention and control of bacterial wilt of enset Cultural practices Despite the considerable research efforts made on enset bacterial wilt in Ethiopia, there is still inadequate information on the epidemiology of the disease particularly on its field spread by insect or other biological vectors (Fikre Handaro et al., 2012). Lack of such information, together with the perennial nature of the plant and absence of natural resistance, have hampered the development of effective control measures. Consequently, management options have focused on methods that reduce the initial inoculum and subsequent spread of the pathogen. The main method practiced to manage enset BW in Ethiopia is the use of cultural practices such as crop sanitation, avoiding the use of contaminated tools, destruction of infected plants by burying or burning, crop rotation and restricting the movement of infected plant materials (Dagnachew Yirgou and Bradbury, 1968; Dereje Ashagari, 1985; Quimio and Mesfin Tessera, 1996). These efforts, usually supported by campaign to create awareness of farmers, have significantly reduced enset BW incidence and thus the subsequent crop loss when implemented on a pilot scale on farmers’ fields by a multidisciplinary team of experts (Million Tadesse et al., 2003; Fikre Handaro et al., 2012). However, the adoption of such practices by many farmers has been inconsistent as they are labour intensive and demand continuous follow up which the farmers are often reluctant or unable to apply effectively. Moreover, the approach has not been scaled up to result in meaningful disease management at the national level. Genetic resistance The implementation of the cultural practices to control enset bacterial wilt did not result in complete management of the disease and hence the use of resistant varieties was considered as the best option as was the case in many other bacterial diseases of plants. Subsequently, considerable research efforts have been made over the last two to select and develop BW resistant enset clones either by experimentally exposing enset clones to bacteria inoculum in greenhouse or under field condition (Gizachew Welde-Michael et al., 2008; Fikre Handaro and Alemar Said, 2016). Some enset clones such as Mazia, Genticha, Badedeti either showed recovery after inoculation or lesser disease incidence compared to susceptible checks. The level of resistance was however not satisfactory to be recommended for practical use or incorporated into breeding programs as results obtained in various experiments were inconsistent perhaps due to variations in the bacterial

108 Adane Abraham strains used or variable amount of inoculum applied in each experiment. Furthermore, the clones which had some level of resistance did not have the desired culinary quality and other desirable agronomic traits sought by the farmers. The problem was further compounded by the absence of national capacity to cross or breed this highly sterile perennial crop to combine such useful traits in a clone or clones preferred by farmers. In the absence of adequate natural resistance to BW, developing resistant enset varieties using transgenic methods was thought to be another viable option. This approach was initiated based on encouraging results obtained by scientists in Uganda who have successfully transformed banana to express two genes namely hypersensitive response-assisting protein gene (hrap) and a plant ferredoxin-like protein gene (Pflp) from sweet pepper (Capsicum annuum) to provide resistance against bacterial wilt (Namukwaya et al., 2012; Tripathi et al., 2010). In this work, many banana lines that showed 100% resistance to either of the two genes have been identified and are currently being tested for gene stability and durability of resistance under advanced field trials in Uganda and Kenya. Since the pathogen causing BW on enset and banana is the same, a collaborative research project was initiated in recent years between Ethiopian scientists and scientist working on transgenic banana in East Africa to expand the impressive results obtained on banana to enset. Progress made so far in this collaborative work include development of regeneration protocols for some enset clones establishment of Agrobacterium-mediated transformation system and obtaining some enset transformant lines (Matheka et al., 2016,; Tripathi et al., 2017). Further research under contained greenhouse and confined field trial is planned in Ethiopia for which permission is required from national biosafety regulatory authorities. Hence, it is reasonable to hope that transgenic BW resistant enset varieties will be made available in Ethiopia in the near future. Biological control Biological control of bacterial plant diseases by microorganisms especially actinomycetes, rhizobacteria and other endophytes have been reported as efficient options for disease management elsewhere. Following the same trend, a number of microorganisms have been evaluated for the potential role in the management of enset bacterial wilt. These include lactic acid bacteria, pseudomonads, growth promoting bacteria, Trichoderma sp, endophytes, and streptomycetes that have shown some promising results under in vitro conditions. In addition, some botanicals (leaf and seed

Ethiop. J. Biol. Sci., 17(Suppl.): 103–119, 2018 109 extracts) were also evaluated and found promising. However, many of the biocontrol agents were ineffective or inconsistent at best in controlling BW when evaluated under field conditions. Recently efforts are being made to evaluate bio-intensive integrated disease management which includes a number of biocontrol agents, plant extracts and plant growth promoting microorganisms. Apart from BW, bacterial corm rot is widely distributed and known to kill both young and mature enset plants. Bacterial corm rot disease was reported in 1991 as important disease affecting enset production. In advanced stage of the disease, the plant easily topples over when pushed, and a rotten corm is observed (Quimio and Mesfin Tessera, 1996). The causative agent has not been identified so far. In conclusion, despite considerable research effort made to understand and manage enset bacterial wilt, the disease continues to be the most important constraint limiting enset production. This is mainly due to the shortage of control options that can be easily and widely applied by the farming community. Efforts to integrate available management options based on cultural practices with innovative strategies including conventional or transgenic resistance and the use of proven biocontrol agents should be strengthened to develop efficient, economic and sustainable management options. There are still a number of issues that need to be addressed by research (Fikre Handaro et al., 2012). The role of insect vectors, vertebrate pests (mole rates and porcupine), bats and domestic animals such as cattle in the transmission of the disease has not yet been adequately investigated. The survival nature of the pathogen during fermentation of enset mass into primary food products and the role of the latter products in the transmission of the pathogen has not been well determined. One of the major challenges is the lack of adequate knowledge of the epidemiology of the pathogen, which had been done only in such fragmented way. Nematode diseases Plant-parasitic nematodes are tiny worms that live mainly in soil and plant parts including roots, leaves and stems. They cause diseases in plants by puncturing the cell and removing the contents using a hollow stylet in their mouth cavity. The common nematodes that attack enset are the root lesion nematodes, the root knot nematodes and the leaf nematodes.

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Root lesion nematode disease of enset is caused mainly by Pratylenchus goodeyi and to a lesser extent P. zeae (Peregrine and Bridge, 1992; Mesfin Mesfin Bogale et al., 2004). These nematodes were known to cause toppling of enset plants during windy days due to severe root rotting and damage of enset roots (Mesfin Tessera et al., 2009). Mesfin Bogale et al. (2004) during an intensive field survey observed that enset cultivars differed in their reaction to P. goodeyii and recommended that the clones should be screened for resistance to these nematodes under greenhouse and field conditions. A significant increase in BW incidence was observed in plants that had been previously infected with root lesion or leaf nematodes when compared to those without nematode infection (Meku Shehabu et al., 2010; Tiedt et al., 1999). Similarly, surveys also indicated that nematode diseases are mostly found in association with bacterial wilt of enset and thus may play a role in development and severity of the disease. The nematodes possibly increase the susceptibility of enset plants to the bacterial wilt by damaging roots and, even play a role in the transmission of the wilt disease (Quimio and Mesfin Tessera, 1996). It was suspected that the root damage creates wounds that act as entry points for bacteria from the surrounding soil. Leaf nematodes cause what is referred to as black leaf streaks of enset. The disease is caused by Aphelencoides ensete (Swart et al., 2000) which mainly attacks leaves of suckers and young seedlings causing immature death of the leaves. Leaf nematodes are found in all enset growing zones (O' Bannon, 1975; Wondirad Mandefro and Kifle Dagne, 2000; Mesfin Bogale et al., 2004). Root knot nematode diseases of enset are caused by three Melodogyne species: M. incognita, M. javanica and M. ethiopica (O'Bannon, 1975; Wondirad Mandefro and Kifle Dagne, 2000; Mesfin Bogale et al., 2004). A study showed that the Ethiopian population of all the three species were found to be highly polymorphic in perinial pattern morphology and stylet length (Wondirad Mandefro and Kifle Dagne, 2000). A quantitative survey conducted by Mesfin Bogale et al. (2004) indicated that the predominant nematode species observed in enset roots was Pratylenchus goodeyi followed by Aphelenchoides ensete and Meloidogyne spp. (Table 2). Similarly, Pratylenchus goodeyi was found in al1 enset samples, while A. ensete was found in 87% of the samples and the Meloidogyne spp. (second stage juveniles) in 60% of the samples.

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Table 2. Population density and frequency of enset common nematodes in Ethiopia (extracted from Mesfin Bogale et al., 2004). Nematode species Prominence value Percent of samples with Nematode number per 100 g nematode fresh wt Pratylenchus goodeyi 5640 100 Aphelenchoides ensete 137 87 Melodogyne spp 26 60 Other parasitic nematode species reported on enset are Helcotylenchus dhystera, H. multicinctus, Hoplolaimus spp., Pratylenchus coffeae, Rodopholus similis, Scutellonema bradys and Tylenchus spp. (Peregrine and Bridge, 1992). These species are encountered at lesser frequency and relatively smaller density. Nematode diseases of enset are economically important in many growing areas causing moderate damage at national level, sometimes causing severe loss in specific localities. However, little research efforts have been made to develop options for their management. Future research should focus on quantifying yield loss and developing feasible control measures. Currently, nematode diseases collectively cause significant damage to enset which can be considered of moderate economic importance although this varies from one location to the other (Mesfin Bogale et al., 2004). However, the possibility remains that the population of nematodes can increase more in the absence of any control measures thereby threatening enset production in the future. Viral diseases Viruses are very small pathogens causing diseases in plants, animals and microorganisms. There is little information on viruses or viral diseases affecting members of genus Ensete in the literature. The only available report in Ethiopia is that of viral chlorotic streak disease causing severe stunting affecting cultivated enset plants reported in 1990's (Quimio and Mesfin Tessera, 1996). The association of bacilliform virus particles has been confirmed with the disease (Mesfin Tessera et al., 1996; Adane Abraham et al., 2018). Subsequent surveys indicated that the disease is widely distributed in different parts of Ethiopia (Quimio and Mesfin Tessera, 1996; Williams and Matile-Ferrero, 1999; Mesfin Tessera et al., 2009). Preliminary assessment of yield loss in two enset clones in natural stands (Table 3) indicated that there was very high reduction in the fresh yield, pseudostem circumference and height (Mesfin Tessera et al., 2009).

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Table 3. The effect of enset virus on yield and yield parameters in two clones in natural stands (Source: Mesfin Tessera et al., 2009). Enset Clones Age Parameters Reduction due to virus (%) Midesho-HS 6 Fresh yield (kg) 93 Circumference (m) 74 Pseud. height (m) 73 Pena-AK 4 Fresh yield (kg) 98 Circumference (m) 77 Pseud. height (m) 64 Recently, a virus with bacilliform particles associated with enset leaf streak disease was characterized using serological and molecular methods (Adane Abraham et al., 2018). The virus particles decorated at medium level using Banana streak OL virus antibodies indicating its serological relatedness to this common banana virus. Sequence analysis indicated that its circular dsDNA genome has 7163 nucleotide base pairs encoding three open reading frames (ORFs) with predicted proteins of 21.5 kDa, 14.5 kDa and 202.5 kDa arranged in a manner typical of badnaviruses (Fig. 1). The virus was shown to be genetically most closely related to Sugarcane bacilliform Guadaloupe D virus earlier reported from sugarcane (Muller et al., 2011) with 73.6% overall nucleotide identity. Based on the current species demarcation criteria of the genus Badnavirus (King et al., 2012), the virus is sufficiently distinct that it should be considered a new species for which the name Enset leaf streak virus (ELSV) is suggested. Using specific primers designed from its sequence, the badnavirus was also detected in 6 out of 40 randomly collected enset samples using virus specific primers in PCR suggesting that ELSV is fairly widely distributed on enset.

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ORF1, 21.5 kDa

ORF2, 4.5 kDa 7163 bp

ORF3, 202.5 kDa

Fig. 1. Organisation of the circular dsDNA genome of Enset leaf streak virus. Circle at the center depicts the dsDNA genome whereas the arrows indicate the deduced open reading frames (ORFs) with indicated encoding capacity of +sense strand. The tRNA binding site sequences are indicated (Source: Adane Abraham et al., 2018). The most serious viral disease of banana worldwide is leaf streak and mosaic caused by a group of viruses collectively called Banana streak viruses (BSVs) (in the genus Badnavirus, family Caulimoviridae). The most common of BSVs in Africa is Banana streak OL virus (BSOLV). PCR tests were done to detect BSOLV using specific primers (5’- CATGCCATGGAGTATACAGCAGAATATGA-3’) and 5’- CAGACTCGAGGCCGACTGAGATAACGTC-3’) on dozens of enset and banana samples originating from farmers field and germplasm accessions from research centers in Ethiopia. Results indicated the absence of BSOLV in any of enset samples while several banana samples were positive with expected 720 bp product amplified (Fig. 2). Hence, only ELSV was so far identified as associated with enset leaf streak disease on enset in Ethiopia in the samples tested. On the other hand, BSOLV is reported from banana for the first time in Ethiopia in this work. Further research is needed to establish whether BSOLV does not affect enset at all or it escaped detection due to small number of enset samples tested.

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M135 7 9 11 13 1517 19 21 21 23 24

Fig. 2. Agarose gel electrophoresis showing PCR products of 720 bp obtained by PCR using BSOLV specific primers on dried banana leaf samples. M is size marker, 1-23 samples from Ethiopia, 24 is positive controls (Source: Adane Abraham et al., 2018). Since enset is vegetatively propagated, one of the practical control measures to minimize possible loss due to viruses is to use virus-free plants which can be obtained by eliminating virus by tissue culture. It should also be noted however that, mealy bugs which are known to be main vectors of badnaviruses (King et al., 2012), may also contribute to the field spread of viruses from infected to healthy plant. In Ethiopia, two species of mealy bugs, Cateanococcus ensete and Planaococcus ficus are reported to be associated with enset (Temesgen Addis et al., 2008; Williams and Matile- Ferrero, 1999). C. ensete is very widely distributed and is one of the most important pests of enset in the country. It is also reported on enset plants suspected to be infected by a badnavirus (Williams and Matile-Ferrero, 1999). Hence, the potential of these mealy bugs in transmitting ELSV should be investigated. Other potential viruses Cucumber mosaic virus and Banana bunchy top virus are the other two common viruses of banana that may affect enset. In addition, enset could harbour any of the several of banana viruses recently reported from East Africa given the close genetic relatedness of banana. It is possible that some of these viruses or their strains or other new viruses can infect enset. Future research on enset should focus on further identification of viruses using conventional and molecular methods including sequence-independent technologies such as next generation sequencing and rolling circle amplification.

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Fungal diseases Fungal foliar diseases of enset are numerous and include leaf spot diseases caused by Phyllostica sp., Pyricularia sp., and Drechslera sp. which commonly affect suckers, seedlings and young plants. In older plants, leaf spots are caused by Cladosporium sp. and Deightoniella sp., Mycosphaerella musicola, which causes sigatoka in banana, is also known to cause destructive leaf spot on enset. Sclerotium wilt and root rot, caused by Sclerotium rolfsii is also encountered but rare. While some of these fungal diseases can be destructive on suckers, seedlings, young transplants and rapidly growing plants up to two years old, infected enset plants normally tolerate these diseases and recover as they grow older. Hence, mature enset plants do not have serious foliar fungal disease problems. Some of the fungal taxa reported as causing enset diseases are known to be pathogens of banana. These include Mycosphaerella musicola that causes the devastating sigatoka disease in banana and Fusarium oxysporum fs cubense causes involved in panama wilt disease. Similarly, the genus Cladosporium is also known as important disease of banana in countries like Kenya (Reddy et al., 1999). However, for many of the fungi listed in literature as causing enset diseases, there is no information as to their pathogenic potential or the fulfilment of Koch's postulate. This raises a question as to whether they are pathogens that have intimate genetic interactions with enset or saprophytes which simply colonize enset surface. For example, many fungi that belong to the genera Drechslera, Cladosporium, Phylosticta or Fusarium are also known to be common saprophytes colonizing surfaces of many plant species. Thus, investigations are needed to unequivocally establish the pathogenic potential of many fungal microbes reported on enset as their mere isolation from plants does not necessarily indicate they are pathogenic. Finally, since many of the fungal genera reported on enset are identified only to genus level, efforts should be made to accurately identify to species level employing both traditional and molecular methods. GAPS AND CHALLENGES IN ENSET PATHOLOGY RESEARCH A close look at previous research in enset pathology reveals a number of gaps and challenges of which the major ones are presented below.  Despite the considerable investment in research on bacterial wilt, technology packages for its management are not yet available.  No enset variety with disease resistance, yield, early maturity and

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culinary quality has yet been developed.  Key epidemiological information such as biological vectors enhancing field transmission of BW pathogen is not available. It is also not clear as to whether the pathogen is disseminated during the processing of enset products for food.  Research on enset diseases in general lacks continuity from problem identification to developing management options. This is often due to student research projects culminating after thesis defense, staff turnover in various institutions, donor-driven project lacking sustainability, and fragmented nationally funded projects with poor coordination.  Researchers focus on “easier to do” research activities (surveys, pathogen characterization, in vitro assays, etc.) at the expense of long-term but more demanding and problem-solving ones (e.g. resistance breeding or crossing experiments, field trials with biocontrol agents, integrated various disease management options).  Research on management of nematodes, viral and fungal diseases has been given little attention.  Lack of knowledge and skills to exploit available genomic sequence data. For example, the complete genomes of both enset and bacterial wilt pathogen were sequenced but no effort was made to exploit these resources using bioinformatic tools.  There is a lack of national coordination on enset research and development. This has resulted in duplication of efforts, fragmentation of results and wastage of resources. CONCLUSION AND RECOMMENDATIONS BW remains the major production constraint of enset. Apart from sanitary measures, more efficient management options do not yet exist to mitigate the enormous losses it incurs. Significant progress has been made on understanding the geographical distribution of the disease, biochemical, physiological and biological properties of the pathogen, the genetic resistance of the host and management options based on sanitary measures. This can be aided by a clear understanding of the molecular basis of interaction between the bacterium and the host plant. Hence, an integrated and multidisciplinary national effort for bacterial wilt management that include diverse approaches ranging from creating conducive environment

Ethiop. J. Biol. Sci., 17(Suppl.): 103–119, 2018 117 for researchers to engaging in conventional resistance breeding and crossing activities to capacity building for transgenic research and biosafety assessment and exploitation of available genomic and biotechnological tools should be in place. It is also evident that enset diseases other than BW have been given little attention generally despite their actual and potential importance in production. For example, the population of the lesion nematode recorded in huge numbers under each enset plant indicates the need for due attention as severe root damage could contribute to easy toppling, and the role of the nematodes as disease vector might further complicate the problem. Similarly, the widespread occurrence and considerable reduction in yield and yield parameters of ELSV indicates that it should be given due attention. It is also very likely that more viruses including those infecting banana in other countries could cause latent but significant effect on enset due to its vegetative propagation. Hence, research efforts should be made to further understand the etiology and biology of these diseases, assess their impact on yield and develop management option of diseases as they may become more important in the near future due to factors like climate change. Overall, integration of the various available management practices and development and effective dissemination of new improved technologies such as the disease-free planting materials and resistant varieties are the best options to manage bacterial wilt and stop other diseases before they become threatening. This calls for a nationally coordinated research on enset diseases and their management. REFERENCES Adane Abraham, Winter, S., Richert-Pöggeler, K.R and Menzel, W. (2018). Molecular characterization of a new Badnavirus associated with streak symptoms on Enset (Ensete ventricosum, Musaceae). J. Phytopathol. 166: 565–571. Castellani, E. (1939). Su un marciume dell’ Ensete. Agricultura Coloniale 33: 297–300. CSA (Central Statistical Authority) (2013). Crop production forecast sample survey, 2013/14 (2006 E.C.). Statistical Bulletin. Federal Democratic Republic of Ethiopia. Dagnachew Yirgou and Bradbury, J.F. (1968). Bacterial Wilt of Enset incited by Xanthomonas musacearum sp.n. Phytopathology 58: 111–112. Dagnachew Yirgou and Bradbury, J.F. (1974). A note on wilt of banana caused by enset wilt organism, Xanthomonas musacearum. E. Afr. Agr. Forestry J. 40: 111–114. Dereje Ashagari (1985). Studies on the bacterial wilt of enset (Ensete ventricosum) and prospects for its control. Ethiop. J. Agric. Sci. 7: 1–14. Fikre Handaro and Alemar Said (2016). Enset clones responses to bacterial wilt disease (Xanthomonas campestris pv. musacearum). Int. J. Appl. Pure Sci. Agric. 45–53. Fikre Handaro, Tariku Hunduma and Endale Hailu (2012). Research achievements,

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experiences and future direction on bacterial wilt of Enset. In: Enset Research and Development Experiences in Ethiopia (Mohamed Yesuf and Tariku Hunduma, eds.). Proceedings of Enset National Workshop, 19-20 August 2010, Wolkite. Gizachew Welde-Michael, Kidist Bobosha, Blomme, G., Temesgen Addis and Mengesha, T. (2008). Evaluation of enset clones against Enset Bacterial Wilt. Afr. Crop Sci. J. 16: 89–95. King, A., Adams, M.J., Carstens, E.C. and Lefkowitz, E.J. (2012). Virus taxonomy. Ninth Report of the International Committee on Taxonomy of Viruses. Elsevier, New York. Matheka, J.M., Tripathi, J., Gebre, E. and Tripathi, L. (2016). Development of an efficient in vitro regeneration system amenable to Agrobacterium mediated transformation of enset. In Vitro Cell. Dev. Biol. Animal 52: S52-S52. Meku Shehabu, Temesegen Addis, Blomme, G. and De Waele, D. (2010). The association between nematodes and Xanthomonas campestris pv. musacearum on banana. Tree and Forestry. Mesfin Bogale, M., Speijer, P.R., Mekete, T., Mandefro, W., Mesfin Tessera and Gold, C. (2004). Survey of plant parasitic nematodes and banana weevil on Ensete ventricosum in Ethiopia. Nematol. Mediterr. 32: 223–227. Mesfin Tessera, Lohuis, D. and Peters, D. (1996). A badnavirus of ensete in Ethiopia. In: Proceedings of the Third Annual Conference of the Crop Protection Society of Ethiopia, pp. 143–148. Mesfin Tessera, Wondirad Mandefro and Bekele Kassa (2009). Review of research on diseases of root and tuber crops in Ethiopia. In: Increasing Crop Production through Improved Plant Protection, pp. 169–202 (Tadesse, A., ed.). Vol. II. Proceedings of the 14th Annual Conference of the Plant Protection Society of Ethiopia held on 19-22, Dec. 2006. PPSE/EIAR, Addis Ababa. Million Tadesse, Kidist Bobosha, Mulugeta Diro, Gizachew Welde-Michael (2003). Enset bacterial wilt sanitary control in Gurage zone. EARO Research Report No. 53. Addis Ababa. Muller, E., Dupuy, V., Blondin, L., Bauffe, F., Daugrois, J.-H., Nathalie, L. and Iskra- Caruana, M.-L. (2011). High molecular variability of sugarcane bacilliform viruses in Guadeloupe implying the existence of at least three new species. Virus Res. 160: 414–419. Namukwaya, B., Tripathi, L., Tripathi, J.N., Arinaitwe, G., Mukasa, S.B. and Tushemereirwe, W.K. (2012). Transgenic banana expressing Pflp gene confers enhanced resistance to Xanthomonas Wilt Disease. Transgenic Res. 12: 855–865. O'Bannon, J.H. (1975). Nematode survey: FAO Report. IAR, Ethiopia. Mimeograph. Peregrine, W.T.H. and Bridge, T. (1992). The lesion nematode, Pratylenchus goodeyi, an important pest of enset in Ethiopia. Trop. Pest Manage.38: 325–326. Quimio, J.A. and Mesfin Tessera (1996). Diseases of Enset. In: Enset-Based Sustainable Agriculture in Ethiopia, pp.188–203 (Tsedeke Abate, Hiebsch, C. and Brandt, S.A., eds.). Proceedings of the First International Workshop on Enset, Dec 13-21 1993. IAR, Addis Ababa. Reddy, K.V.S., Ngode, L., Ssenyonga, J.W., Wabule, M., Onyango, Adede, M.T.O. and Ngoze, S. (1999). Management of pests and diseases of banana in Kenya: A status report. In: Mobilizing IPM for Sustainable Banana Production in Africa, pp. 215–223 (Frison, E.A., Gold, C.S., Karamura, E.B. and Sikora, R.A., eds.).

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Proceedings of the Workshop on Banana IPM held in Nelsprut 1998, 11, 23-28, Montpelier. Swart, A., Bogale, M. and Tiedt, L.R. (2000). Description of Aphelenchoides ensete sp. n. (Nematoda: Aphelenchoidi- dae) from Ethiopia. J. Nematode Morphology Syst. 3: 69–76. Temesgen Addis, Firdu Azerefegne and Blomme, G. (2008). Density and distribution of enset root mealy bugs on enset. Afr. Crop Sci. J. 16: 67–74. Tiedt, L.R., Swart, A. and Bogale, M. (1999). The association between Aphelenchoides ensete n. sp. and Xanthomonas campestris in the infection of Ensete ventricosum in Ethiopia. Microscopy Society of Southern African-Proceedings, 27: 81. Tripathi, L., Matheka, J., Merga, I., Gebre, E., and Tripathi, J. (2017). Efficient regeneration system for the rapid multiplication of clean planting material of Ensete ventricosum (Welw) Cheesman. In Vitro Cell. Dev. Biol. Plant 53: 624– 630. Tripathi, L., Mwaka, H., Tripathi, J.N. and Tushemereirwe, W.K. (2010). Expression of sweet pepper Hrap gene in banana enhances resistance to Xanthomonas campestris pv. musacearum. Mol. Plant Pathol. 11: 721–731. Tripathi, V., Mwangi, M., Abele, S., Aritua, V., Tushemereirwe, W.K. and Bandyopadhyay, R. (2009). Xanthomonas wilt. A threat for banana production in East and Central Africa. Plant Dis. 93: 440–451. Tushemereirwe, W., Kangire, A., Ssekiwoko, F., Offord, L.C., Crozier, J., Boa, E., Rutherford, M. and Smith, J.J. (2004). First report of Xanthomonas campestris pv musacearun banana in Uganda. Plant Pathol. 53: 802. Williams, D.J. and Matile-Ferrero, D. (1999). A new species of the mealy bug genus Catalenococcus Ferris from Ethiopia on Ensete ventricosum, a plant infected by a virus [Hemiptera, Pseudococcidae; Musaceae]. Rev. Fr. Entomol.21: 145–149. Wondirad Mandefro and Kifle Dagne (2000). Morphological variation of root-knot nematode populations from Ethiopia. Pest Manage. J. Ethiop. 4: 19–28.

Ethiop. J. Biol. Sci. 17(Suppl.): 121–132, 2018 © The Biological Society of Ethiopia, 2018 ISSN: 1819-8678 LAND-USE CHANGES IN THE ENSET-BASED AGROFORESTRY SYSTEMS OF SIDAMA, SOUTHERN ETHIOPIA, AND ITS IMPLICATIONS FOR AGRICULTURAL SUSTAINABILITY

Tesfaye Abebe1

ABSTRACT: The enset-based agroforestry systems of Southern Ethiopia provide millions of households with a variety and continued production of food and other products. These systems exist in the tropical highland (Woyna dega) zones at altitudes of 1500-2300 m.a.s.l., where enset is grown in an intimate integration with coffee, vegetables, fruits, root and tuber crops, cereals and different types of trees. The study was conducted in the Enset- based agroforestry systems of Sidama administrative zone where 22% of enset in the country is produced. Here, enset covers about 26% of the total farm area and it serves as a staple food for millions of people. The systems combine production with environmental protection, and hence contribute to food security and long term wellbeing of the population. The stability of this system depends both on its diversity and on the specific characteristics of the two main native and perennial crops, enset and coffee. However, the composition and diversity of the enset-based agroforestry systems is changing in recent years as farmers respond to emerging challenges and opportunities. Increasing fragmentation of land and improvement in market access is leading to expansion of monoculture food crops, mainly maize and cash crop, khat. These crops are expanding at the expense of enset and coffee. Since enset is the most productive crop per unit area of land and time, the decrease in cultivation area of enset is likely to affect food security situation in the area. Moreover, the age structure of enset plantations show that the vast majority of farms have very small proportion of mature and harvestable enset plants. This aggravates the food shortage and forces farmers to shift to cultivation of annual crops such as maize to respond to the family’s immediate food demand. This paper attempts to reveal that the future of these systems lies in the maintenance of enset as a key crop, because it plays significant roles towards the economic and ecological sustainability of the systems. It also demonstrates the strategies and approaches that could be followed to reverse the declining trends in enset cultivation.

Key words/phrases: Agricultural intensification, Enset-coffee systems, Land-use, Sidama, Tropical highlands.

1 School of Plant and Horticultural Sciences, Hawassa University, P.O. Box 5, Hawassa, Ethiopia. E-mail: [email protected]

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INTRODUCTION Enset (Ensete ventricosum (Welw.) Cheesman is a staple or co-staple food crop for an estimated population of 15 million people in the South and South-western parts of Ethiopia. It is cultivated within altitudes of 1500- 3100 metres above sea level, in areas having a mean annual rainfall of 1000- 1800 mm and a mean temperature of 10-20°C (BODEP, 1997). Temperature plays a significant role in the growth rate of enset. Accordingly, at the altitudinal range of 1500-2300 metres (Woyna Dega areas) where mean annual temperature is 15-20°C, enset grows fast and reaches full maturity in 6-8 years. On the other hand, in the high altitudes of 2300-3100 metres (Dega areas), where mean temperature drops to 10-15°C, it takes an average of 8-10 years and even more, to reach full maturity (BODEP, 1997). The major enset growing areas in Southern Ethiopia are Sidama, Gedeo, Gurage, Hadiya, Kembatta, Wolayita, Gamo, Gofa and Kefficho administrative zones. This study was carried out in Sidama administrative zone where 22% of enset in Ethiopia is produced (Fig. 1). In the tropical highland (Woyna dega) zones of Sidama at altitudes of 1500-2300 m.a.s.l., the diversity of crops is generally high and enset is grown in integration with coffee, fruits, vegetables, cereals, trees and livestock in multistorey agroforestry systems. Here, the climatic and soil conditions are suitable for the production of different types of crops, including high value crops such as coffee and khat (Catha edulis), and it is not clear how farmers allocate their land for the different types of crops in order to ensure attainment of household food security and income. The age structure of the enset crop, which gives an indication on sustainability of food supply, is not also known. This paper attempts to analyze the land-use dynamics of the enset-coffee agroforestry systems, the age structure of enset plantations and the overall effects of these changes on sustainability of the enset-coffee agroforestry systems of Sidama administrative zone in Southern Ethiopia. STATUS OF THE ENSET-BASED AGROFORESTRY SYSTEMS Composition and structure of the enset-coffee land-use systems Most of the enset-coffee agroforestry systems of Sidama have evolved from forests. Farmers maintain the upper storey trees and clear the undergrowth to open up space for planting enset, coffee and other crops. More species and varieties of crops and trees are gradually introduced (Tesfaye Abebe and Bongers, 2012). In addition to species diversity, a high level of genetic diversity is found in two major crops, enset and coffee.

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Fig. 1. Map of Sidama administrative zone in Southern Ethiopia. The diversity and density of the crops vary spatially and temporally. The agroforestry systems show four distinct vertical layers of crops. Vegetables, spices, beans, root and tuber crops occupy the lowest strata up to 1.5 m. Coffee, enset, maize, khat, sugarcane and some fruit trees, such as banana and papaya, occupy the layer between 1.5 and 5 m. Larger fruit trees, such as avocado and white sapote, some shrubs and pollarded shade trees dominate the third layer between 5 and 12 m., and the fourth layer, above 12 m, which could sometimes extend up to 35 m high, is dominated by timber- producing shade trees (Tesfaye Abebe et al., 2006; 2010). The lower most stratum is the richest in species (64%); the second stratum is the densest because of the heavy dominance of enset and coffee (Tesfaye Abebe, 2005). The key components of these agroforestry systems are the perennial crops enset and coffee, with mean coverage of over 60% of the farm areas (Tesfaye Abebe et al., 2010). The high diversity of species, which combines crops, trees and livestock with different uses and production cycles, is considered as essential component of sustainable agriculture because of the wide socioeconomic and ecological roles it plays in the systems. The roles include, among others, year-round production of food and wood products, decreased risks of production failure, increased productivity over time (Netting and Stone, 1996), maintenance of genetic diversity and landscape protection (Perfecto 124 Tesfaye Abebe et al., 2009; Trenbath, 1999). Food species with high energy content are dominant crop species in the farms, and enset is the most important staple food crop. The role of enset in the system Enset is a multipurpose crop that produces food, fodder, fiber and other products. Food is extracted from the pseudostem and corm since the starch accumulated in the leaf sheaths and the corm are the main products. Three types of food products are namely, kocho, bulla and amicho. Yield of enset varies with the landraces used and with the climate. According to the nationwide survey made on enset production (CSA, 1997), the average yield of kocho and bulla per plant is 30.15 and 1.04 kilograms, respectively. Using an average density of 2000 enset plants per hectare and a harvesting age of six years, its productivity will be 10 tons ha–1yr-1, and this puts it among the highest productive crops in the country. Enset guarantees food security and stability in the household economy as the processed produce can be stored for a long time and live plants can be maintained on farm and harvested any time when the need arises (Almaz Negash, 2001; Admasu Tsegaye, 2002), which is why enset areas are not prone to famine (Desalegn Rahmato, 1995). In addition to food, enset has many other uses. The fiber extracted during processing is used locally for making strings, ropes and other products, or it is sold in markets for use by fiber factories. The leftover during harvesting, thinning and the leaves are important fodder sources for livestock. The leaves as well as the dry leaf sheaths are also used as packing, wrapping and binding materials. Moreover, some enset landraces are used as medicine for human beings and livestock. Enset also plays a very important environmental role. It protects the soil from erosion and runoff, it serves as shade and improves the microclimate for the undergrowth, and the litter from the leaves and other parts improve soil fertility. Unlike annual plants, small portion of the biomass is taken out of the system at harvesting, while the largest portion is returned directly as litter or indirectly through the manure. In general, enset has ideal attributes for low-input sustainable agricultural production systems: it is high yielding, it can be harvested any time once it is four years old, it doesn’t require external inputs, it protects and/or enhances the environment, and it has multiple functions. It is, therefore, no wonder that it has been supporting a dense population of over 500 persons per km2 in areas where it is used as staple food.

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Land-use changes in the enset-coffee systems Sidama administrative zone is a major enset-growing area accounting for 22% of the total enset production area in the country (CSA, 1997). In the enset-coffee agroforestry systems of Sidama, enset covers an average of 26.4% of the total farm area (Tesfaye Abebe, 2005), with variation across sites and between farms. The proportion of land allotted to enset is more or less similar across the different wealth groups of farmers. Large farm holders can produce sufficient enset for consumption and allot an increasingly larger area to grow cash crops such as coffee and khat. Poor farmers have a slightly higher share of land under maize because, with a lower farm size, farmers cannot depend solely on enset, which takes at least four years to mature, but also need early maturing crops such as maize and sweet potato. This illustrates the fact that enset, as the main staple crop of the household, is a strategic crop and determines cropping plans, land-use, use of technology and consumption and marketing decisions (Desalegn Rahmato, 1995). If a household has sufficient enset plants for consumption, it grows high value crops for the market. If there is no market, cash crops will be curtailed in favour of food crops. If the number of mature, ready-to- harvest enset plants on the farm is insufficient to feed the family during the year, more land will be used to grow annual food crops such as maize and sweet potato. These additional annual crops are planted in the part of the farm usually allocated for transplanting enset. The nature of enset cultivation lends itself well to such flexible decisions. For the first two years enset is often grown in very high densities of about 10,000 or more plants per ha. If there is ample space, the thinnings are transplanted into the new plots; if there is not enough space, the thinnings are used as livestock feed or incorporated in the soil. The crucial decisions that are made by the households to obtain a sustainable yearly harvest of enset are the total farm area to be planted with enset and the distribution of enset plants over age classes. In the enset- coffee agroforestry systems of Sidama, enset is normally harvested after five to eight years. If we take the harvesting age of six years, there will be six age classes of enset plantations each having proportional area coverage of 16.7%. This is not the case, however. In a study of age structure of enset in these land-use systems, Tesfaye Abebe and Bongers (2012) found that enset fields are dominated by immature enset plants; about 90% of the plants were less than four years old, while only 10% were five to eight years old. Poor farmers in particular have a smaller area under matured enset. The ratio of mature enset (age older than five years) increased with wealth: 4.7% (poor), 126 Tesfaye Abebe

10% (medium) and 17.3% (rich) (Fig. 2). This confirms that farmers with a smaller area of farmland cannot afford to depend on enset only, as it takes at least four years to be harvested. Poor farmers are therefore forced to fill the consumption gap with annual food crops, such as maize and sweet potato – crops that are often grown as monocultures because of their high light requirement.

Fig. 2. Age structure of enset plantations among the different wealth category of farmers in the enset- based agroforestry systems of Sidama. As the dry matter yield of enset per unit area and time is much higher than other crops (Admasu Tsegaye and Struik, 2001), and due to the large-scale environmental benefits of enset, research and extension efforts should focus on reversing the declining trend of enset plantations on small farms through a systematic allotment of enset plantations. To achieve this, the number of enset plants sufficient for annual consumption of a household should be estimated, and that number should be planted every year during the whole Ethiop. J. Biol. Sci., 17(Suppl.): 121–132, 2018 127 rotation period. For instance, if 60 mature enset plants are required for the household’s annual consumption and the rotation cycle (harvesting age) is six years, then a total of 360 enset plants divided into six age categories (1- 6) of 60 enset plants each should be grown. At the end of the sixth year the mature 60 plants can be harvested and replaced by new planting materials. This rotation would help to obtain a sufficient and regular yield from enset while maintaining the complex and integrated nature of the agroforestry systems. In addition to farm size, access to markets also affects farmers’ decision to allocate land for enset production. Farmers with good market access, either because of the physical proximity of markets or good access to major roads, devote a smaller proportion of their land to growing enset and a higher proportion to cash crops. This is because market access enables them to sell the cash crops and buy what they need for subsistence. The variation among farmers and the impacts of such drivers show that the land-use systems in the Sidama region are dynamic; farmers make individual choices and respond to emerging challenges and opportunities. When per capita land holding declines, mostly as a result of increased population pressure, farmers tend to produce more staple food crops than cash crops. Among the food crops, they give priority to annuals rather than perennials (such as enset), because of immediate subsistence needs. Farmers also assess their comparative economic advantage and respond to increasing market opportunities, as was manifested in the expansion of khat in the study areas (Tesfaye Abebe et al., 2010). The enset-coffee agroforestry systems already carry a very dense population, which is still growing fast. The high population growth (2.5%) is likely to result in increased fragmentation of farmlands. This trends are likely to result in further expansion of annual crops and a reduction in the perennial components (crops and trees) and livestock, which are vital for the sustenance of the system. Likewise, the increasing commercialization of crops such as khat, which is associated with an increased share of annual food crops (maize and sweet potato), is leading to the reduction in the key native perennial crops, enset and coffee. The share of native and ecologically friendly multipurpose trees declines with better road access, while that of eucalyptus tends to increase. This will lead to further uniformity of the landscape.

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DISCUSSION Effects of the land-use changes on productivity and sustainability A high species diversity which combines crops, trees and animals having different uses and production cycles have a potential to maintain the resource base, the land. Of course, this would depend on the quantity and quality of the inputs used in the system. Many studies propose the use of ‘sustainable intensification’ (Tilman et al., 2002; Pretty et al., 2003; Godfray et al., 2010), which seeks to combine increased production of food from the same area of land with a reduction in environmental impacts (Royal Society of London, 2009). While the enset-coffee agroforestry systems of Southern Ethiopia display the characteristics of sustainable agriculture, there is room for increasing productivity through intensification. If intensification involves a reduction in plant diversity and the perennial nature of the systems, leading to the development of monoculture fields, this could disrupt the ecosystem services provided by the integrated multistorey agroforestry systems. However, integrating high value crops into the systems without significantly affecting the composition and diversity of components could lead to sustainable intensification. Hence, maintaining the existing components of the enset-coffee agroforestry systems would contribute to its ecological and socioeconomic sustainability. Ecological sustainability indicates the extent to which natural resources are conserved so that farming can be continued, while economic sustainability shows its suitability and adaptability to local farming conditions and its economic viability (Pretty et al., 2003; Ojiem et al., 2006; Peyre et al., 2006; Holden and Linnerud, 2007). Below, we evaluate the ecological and socioeconomic sustainability aspects of the enset-coffee agroforestry systems and justify the need for their maintenance. Ecological sustainability aspects Several features of the enset-coffee agroforestry systems are important for the ecological sustainability, including (1) maintenance of species diversity, which is important for risk spreading and minimization, genetic conservation of native species, efficient resource use and biological pest control; (2) reduced use or elimination of soluble or synthetic fertilizers, increased or improved use of manure and other organic materials as soil ameliorants, and soil conservation; (3) reduced use or elimination of chemical pesticides, replacing these with integrated pest management practices and system diversity; and (4) self-sufficiency, by using on-farm or locally available ‘internal’ resources and a minimum or conditional use of Ethiop. J. Biol. Sci., 17(Suppl.): 121–132, 2018 129 purchased ‘external’ resources, which contributes to the long-term conservation of the resource base and environmental resilience of the systems (Tesfaye Abebe et al., 2006; Tesfaye Abebe and Bongers, 2012). Socioeconomic sustainability aspects The maintenance of high species diversity in the enset-coffee agroforestry systems also contributes to socioeconomic stability. As in other agroforestry systems, the diversity of crop, tree and livestock species with different uses and production cycles enables the year-round production of different products, reduces the risk of production failure, allows flexible use of labour and enables efficient cycling of locally available resources, which means that production does not depend on external inputs (Kumar and Nair, 2006; Tesfaye Abebe, 2005). Moreover, the enset-coffee agroforestry systems also possess several specific features that promote socioeconomic sustainability. They not only have a high species diversity, but also a high diversity in functional crop types, notably staple food crops and cash crops, in addition to the usual supplementary home garden crops (Tesfaye Abebe et al., 2006). The carbohydrate-rich basic food crops, enset and maize are supplemented by pulses, vegetables, fruits and animal products that provide proteins, fats and vitamins, and by trees that provide resources for construction and household energy. This is of crucial importance for households, especially poor families. The cash crops - coffee, khat and pineapple that are incorporated into the systems, also give a more balanced household income. Both the diversity of crops and the inclusion of the perennial enset spread the risk to households of individual crop failures. The possibility of flexibly harvesting enset as a staple food is one of the main reasons why the Southern highlands of Ethiopia are relatively free from hunger (Desalegn Rahmato, 1995; Brandt et al., 1997). Like the ecological sustainability of these agroforestry systems, its socioeconomic sustainability cannot be explained by its species diversity alone, but also by the specific features of the two key species, enset and coffee. Enset is both a food crop and a provider of different products, such as fiber and fodder. It is therefore ideally suited to low-external input agricultural production systems (Almaz Negash, 2001; Bizuayehu Tesfaye, 2002), while its high productivity and multiple functions provide sustenance for a very dense population, which is often two to three times higher than in the cereal-based systems found in other parts of Ethiopia (Tesfaye Abebe, 2005). Coffee serves as a main cash crop supplementing the mainly subsistence-oriented enset production. Consequently, not only from an 130 Tesfaye Abebe ecological point of view, but also from a socioeconomic point of view, coffee and enset can be considered as key species. CONCLUSION AND RECOMMENDATIONS The traditional enset-coffee agroforestry systems are characterized as a sustainable land-use system, but this does not mean that they are not subject to change. Decreasing farm size and increased commercialization is affecting the systems. The shift from the traditional enset-coffee systems towards inclusion of other food and cash crops has increased household income. However, the expansion of open-field food crops (maize, sweet potato) and of monocultural cash crops (khat, pineapple), causes not only a gradual loss of species diversity and tree biomass, but also a decrease in the perennial crops and native tree species, to the detriment of the dominance of the two key species, enset and coffee. As these are considered to play a significant role in the stability and resilience of the agroforestry system, it is expected that the land-use change will have negative impacts on the landscape. It results in a gradual reduction of the ecological benefits derived from these integrated and complex systems, which threatens their long-term sustainability. We should therefore opt for the maintenance of the perennial component in systems and the integration of new crops into the existing multistorey system, without affecting the biodiverse nature of enset-coffee agroforestry systems and without losing their essential key species, enset and coffee. This can be achieved through directed extension services by government institutions and local organizations. Additional research should focus on the integration of expanding cash crops (such as khat and pineapple) into the existing systems without changing the multistorey structure of the home gardens. As enset plant produces the highest volume of food per unit area and time, and because of its different end uses and diverse ecological roles, the future of these home gardens depends on the maintenance of enset-based staple food production. Thus, strategies should be developed to reverse the increasing dependence on maize and enhance the systematic production of enset. REFERENCES Admasu Tsegaye and Struik, PC. (2001). Enset (Ensete ventricosum (Welw.) Cheesman) 'Kocho' yield under different crop establishment methods as compared to yields of other carbohydrate-rich food crops. Neth. J. Agric. Sci. 49: 81–94. Admasu Tsegaye (2002). On Indigenous Production, Genetic Diversity and Crop Ecology of Enset (Ensete ventricosum (Welw.) Cheesman). Ph.D. Dissertation, Wageningen University, Wageningen. Almaz Negash (2001). Diversity and Conservation of Enset (Ensete ventricosum Welw. Ethiop. J. Biol. Sci., 17(Suppl.): 121–132, 2018 131

Cheesman) and its Relation to Household Food and Livelihood Security in South-western Ethiopia. Ph.D. Dissertation, Wageningen University, Wageningen. Bizuayehu Tesfaye (2002). Studies on Landrace Diversity, In Vivo and In Vitro Regeneration of Enset (Ensete ventricosum Welw.). Ph.D. Dissertation, Humboldt University, Berlin. BODEP (Bureau of Development and Economic Planning) of Southern Nations, Nationalities and CSA (Central Statistical Authority) (1997). Report on results of enset sample survey. Statistical bulletin 184, Addis Ababa. Brandt, S.A., Spring, A., Hiebsch, C., McCabe, J.T., Endale Tabogie, Mulugeta Diro, Getachew Wolde-Michael, Gebre Yntiso, G., Shigeta, M. and Tesfaye, S. (1997). The Tree against Hunger. American Association for the Advancement of Science, Washington D.C. CSA (1997). Area, production and yield of crop of private holdings in 1996/97 in Meher season. Addis Ababa. Desalegn Rahmato (1995). Resilience and vulnerability: Enset agriculture in Southern Ethiopia. J. Ethiop. Stud. 28: 23–51. Godfray, H.C.J., Beddington, J.R., Crute, I.R., Haddad, L., Lawrence, D., Muir, J.F., Pretty, J., Robinson, S., Thomas, S.M. and Toulmin, C. (2010). Food security: the challenge of feeding 9 billion people. Science 327: 812–818. Holden, E. and Linnerud, K. (2007). The sustainable development area: Satisfying basic needs and safeguarding ecological sustainability. Sustain. Dev. 15: 174–187. Kumar, B.M. and Nair, P.K.R. (eds.). (2006). Tropical Home Gardens: A Time-tested Example of Sustainable Agroforestry. Springer, Dordrecht. Netting, R.M.C. and Stone, M.P. (1996). Agrodiversity in a farming frontier: Kofyar smallholders on the Benue plains of Central Nigeria. Africa 66: 52–69. Ojiem, J.O., De Ridder, N., Vanlauwe, B. and Giller, K.E. (2006). Socio-ecological niche: A conceptual framework for integration of legumes in smallholder farming systems. Int. J. Agric. Sustain. 4: 79–93. Perfecto, I., Vandermeer, J. and Wright, E.L. (2009). Nature’s Matrix: Linking Agriculture, Conservation and Food Sovereignty. Earthscan Ltd., London. Peyre, A., Guidal, A., Wiersum, K.F. and Bongers, F. (2006). Home garden dynamics in Kerala, India. In: Tropical Home Gardens: A Time-tested Example of Sustainable Agroforestry, pp. 87–103 (Kumar, B.M. and Nair, P.K.R., eds). Springer, Dordrecht. Pretty, J.N., Morison, J.I.L. and Hine, RE. (2003). Reducing food poverty by increasing agricultural sustainability in developing countries. Agri. Ecosyst. Environ. 95: 217–234. Royal Society of London (2009). Reaping the Benefits: Science and Sustainable Intensification of Global Agriculture. Royal Society of London, London. Tesfaye Abebe (2005). Diversity in Agroforestry Systems of Southern Ethiopia. Ph.D. Dissertation, Wageningen University, Wageningen. Tesfaye Abebe, Wiersum, K.F., Bongers, F. and Sterck, F. (2006). Diversity and dynamics in home gardens of Southern Ethiopia. In: Tropical Home Gardens. A Time- tested Example of Sustainable Agroforestry, pp. 123–142 (Kumar, B.M. and Nair, P.K.R., eds.). Springer, Dordrecht. Tesfaye Abebe, Wiersum, K.F. and Bongers, F. (2010). Spatial and temporal variation in crop diversity in agroforestry homegardens of Southern Ethiopia. Agroforestry 132 Tesfaye Abebe

Syst. 78: 309–322. Tesfaye Abebe and Bongers, F. (2012). Land-use dynamics in enset-based agroforestry home gardens in Ethiopia. In: Forest People Interfaces: Understanding Community Forestry and biocultural Diversity, pp. 69–85 (Arts, B., Van Bommel, S., Ros-Tonen, and Verschoor, G., eds.). Wageningen Academic Publishers, Wageningen. Tilman, D., Cassman, K.G., Matson, P.A., Naylor, R. and Polasky, S. (2002). Agricultural sustainability and intensive production practices. Nature 418: 671–677. Trenbath, B.R. (1999). Multispecies cropping systems in India: Predictions of their productivity, stability, resilience and ecological sustainability. Agroforestry Syst. 45: 61–107.

Ethiop. J. Biol. Sci. 17(Suppl.): 133–161, 2018 © The Biological Society of Ethiopia, 2018 ISSN: 1819-8678 DIVERSITY, CHALLENGES AND MANAGEMENT OF ENSET (ENSETE VENTRICOSUM (WELW.) CHEESMAN) BY KEMBATTA PEOPLE, SOUTHERN ETHIOPIA

Melesse Maryo1,*, Sileshi Nemomissa2 and Tamrat Bekele2

ABSTRACT: Enset (Ensete ventricosum (Welw.) Cheesman) is an endemic multipurpose Ethiopian crop with a potential for food security for it grows in areas where there is a high population pressure and scarce cultivable land. Studies indicate that pests and diseases are among the challenges to sustainability of enset agriculture. A survey on diversity, challenges and management of enset was conducted in Kambatta Tembaro Zone. Twelve farmscapes each with 15 sampling sites were randomly selected for the study. The identification of enset landraces and recording of data on criterion for landraces identification and selection, and cultural management practices were conducted with the help of farmers using interviews, questionnaire and group discussion. Shannon Index (H’) and multiple linear regression, and ANOVA were employed to analyze the data. Farmers’ characterization identified a total of 111 named enset landraces, of which 21 had medicinal value. There was high significant difference (P<0.01) in enset landraces among economic classes and agroclimatic zones. Dega agroclimatic areas cultivated twice the number of enset landraces in kola areas (mean = 11.5/HH). The number of enset landraces per farmscapes ranged from 8 to 61 with an average of 27.3 whereas the mean Shannon (H') and evenness (E) indices were 1.84 and 0.64 in the zone, respectively. Multidimensional preference ranking showed that amicho, fiber quality, storability, yield, and earliness were useful in discriminating enset landraces. Enset diversity increased with access to market and wealth status of the households. Wild mammalian pests, enset bacterial wilt, and shortage of farmland were challenges to sustainability of enset agriculture. Apposite attention should be given by the government to incorporate enset in the current extension system. Furthermore, experts in ethnobotany, anthropology, microbiology and other appropriate fields should work together with the local people for a workable solution.

Key words/phrases: Amicho, Characterization, Enset diseases, Landraces, Preference ranking.

1 Department of Biology, Dilla University. E-mail: [email protected] 2 Department of Plant Biology and Biodiversity Management, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia. E-mail: [email protected]; [email protected] * Author to whom all correspondence should be addressed 134 Melesse Maryo et al.

BACKGROUND AND JUSTIFICATION Heterogeneous landscapes, traditional agricultural practices, and inaccessibility have created and maintained diverse subsistence agroecosystems (Samberg et al., 2010). The Ethiopian highlands are centres of diversity for several useful indigenous cultivated crops, including enset (Ensete ventricosum (Welw.) Cheesman) (IBC, 2005). Enset is an endemic multipurpose tree-like perennial herbaceous crop belonging to Family Musaceae (Edwards et al., 1997). It possessed many recognizable farmer varieties or landraces. Landraces are dynamic population(s) of cultivated plants that have historical origin, discrete identity, genetically diverse, locally adapted and culturally selected (Camacho Villa et al., 2005). They are recognized by farmers on the basis of a number of morphological and agronomic criteria (Brush, 2000; van de Wouw et al., 2009). Many scholars have reported different numbers of enset landraces from various localities in Ethiopia, for instance, 78 from Ari (Shigeta, 1990), 65 from Kafa and Sheka (Almaz Negash, 2001), 42 from Sidama (Tesfaye Abebe et al., 2010), and 105 from Gamo Gofa (Sabura Shara and Mulugeta Diro, 2012). Landraces are named differently among different cultures and localities in Ethiopia. As a result, regardless of the existing similarity among cultures, different enset landrace numbers were reported. The inconsistency of naming pattern due to the lack of clear and common identification techniques probably has created inflated landrace reports in most cases. Enset is distributed at altitudes between 1600 and 3000 m a.s.l., and chiefly propagated vegetatively (Almaz Negash et al., 2002). It was noted for its tolerance, storability for long periods, cultural values (Eyasu Elias, 2003), and for its multiple uses (Shigeta, 1990), i.e., both food and non-food uses of enset (Brandt et al., 1997). The major foods from enset are kocho and bulla, obtained from pseudostem and leaf petioles (Yemane Tsehaye and Fassil Kebebew, 2006). But amicho is obtained from the underground corm and consumed after cooking. Bulla is a water insoluble starchy product obtained by squeezing the scrapped pseudostem (leaf sheath) and corm. Scholars view enset as a food security (Admasu Tsegaye and Struik, 2002) for over 20% of the populations of Ethiopia living in the southern and southwestern parts (Gizachew Wolde-Michael et al., 2008), covering about 18% of the farm, in mixture with coffee, kale, and others (Tilahun Amede and Endale Tabogie, 2006). Furthermore, some enset varieties are used for both humans and livestock to cure bone fractures, birth problems, and diarrhea (Brandt et al., 1997). Ethiop. J. Biol. Sci., 17(Suppl.): 133–161, 2018 135

Most enset plant parts serve as cattle feed whereas livestock offer manure for soil fertility, chiefly for enset in the home gardens. Furthermore, enset culture is a polyculture where young enset plants are intercropped with annuals (e.g., maize,), and older enset plants with perennials such as coffee , which is shaded by enset (Tadesse Kippie, 2002). As to Admasu Tsegaye and Struik (2002), the intercropped annual crops are used to supplement the low protein and vitamin content of enset products and generate cash from sales. Therefore, enset cultivation is suitable for sustainable agricultural systems due to its contribution to soil fertility, its multiple use, its accessibility at any time, relatively high productivity, cultural practices and varietal differences (Genet Birmeta, 2004). However, the sustainability of enset cultivation is threatened by a number of factors (Tsedeke Abate et al., 1996), such as wild animals pests, e.g., crested porcupine (German et al., 2012), enset root pests (Temesgen Addis, 2005) and leaf pest such as leaf hopper, population pressure, degradation of the soil (Tsedeke Abate et al., 1996; Teshome Yirgu, 2016), and cash oriented crop production (Almaz Negash, 2001; German et al., 2012). Moreover, different types of diseases (fungal, bacterial and viral) (Tsedeke Abate et al., 1996) as well as poor post-harvest technology (Solomon Tekalign and Suneetha, 2012) are challenging enset production. Consequently, the vulnerability of enset to genetic erosion was reported (Admasu Tsegaye and Struik, 2002; Abrham Shumbulo et al., 2012). Furthermore, the scarcity of farmland that led many young farmers to focus on few short season agricultural crops, the impact of climate, and drought resulted in the loss of several useful enset landraces. Significant number of studies were conducted on enset, mainly on enset production and utilization in Ethiopia (Taye Bezuneh and Asrat Feleke, 1966), enset based foods, biotechnology and enset yield (Tsedeke Abate et al., 1996), enset diversity (Shigeta, 1990; Admasu Tsegaye and Struik, 2002; Almaz Negash et al., 2002; Bizuayehu Tesfaye and Lṻdders, 2003; Zippel, 2005; Yemane Tsehaye and Fassil Kebebew, 2006; Abrham Shumbulo et al., 2012; Zerihun Yemataw et al., 2016), enset challenges (Teshome Yirgu, 2016), including enset bacterial wilt (also called Enset Xanthomonas Wilt or EXW) (Kidist Bobosha, 2003; Gizachew Wolde- Michael et al., 2008). In the past the majority of researches on Ethiopian agriculture have focused mainly on the cereal-based systems (Brandt et al., 1997), and the agricultural policy of the country gave little regard for indigenous enset 136 Melesse Maryo et al. production (FAO, 2010). Kambatta Tembaro Zone was suggested to be rich in enset landraces (Ethiopian Biodiversity Institute, 2010). The extent, distribution, and management of available diversity as well as factors that control enset diversity needs appropriate investigation for the development of efficient conservation strategies (Clawson, 1985). Therefore, this study was aimed to examine the diversity and management of landraces across the agroclimatic zones by the people in Kembatta Tembaro Zone. It mainly focuses on documenting the available enset landraces, uses, and factors governing enset diversity and distribution, and examining the challenges that influence enset production. MATERIALS AND METHODS The study area, the Kembatta Tembaro (KT) Zone, is one of the Zones in Southern Nations, Nationalities and Peoples’ Region, located between latitude 7.10 –7.500 N and 37.31-38.070 E longitude and found between altitudinal ranges of 501 and 3080 m a.s.l. It covers a total area of 1523.6 sq. km (KTZARD, 2011), and it is divided into seven districts or Woredas for administrative purpose. The study area has a bi-modal rainfall distribution. The main rainy season stretches from July to September/October with the highest peak in August is locally called Ojaa. The minor rainy season called Gilaallo and extends from March to the beginning of June. At Durame meteorological station (National Meteorological Agency) of the zonal capital, the maximum mean temperature record was 26.8°C in June, and the mean annual temperature and mean annual rainfall was 19.3°C and 1144 mm, respectively. Kembatta Tembaro Zone has a population of 1,055,828, out of which the number of males and females was 559,713 and 496,115, respectively (KTZARD, 2011) and 86% of the people live in rural areas (Central Statistical Authority, 2007b). The average land holding per house hold (HH) is less than 1 hectare and there were an average of 6 persons to a household, and about 708 people per sq. km (Central Statistical Authority, 2007a). The Zone has three agroclimatic zones, namely Dega (cool and humid) 25%, WoynaDega (cool semi-arid) 67% and Kolla (Semi desert) 8%. Of the total area of the land, about 75% is cultivated (KTZARD, 2011). Dry ever green afromotane forest and grassland complex and Combretum-Terminalia woodland and wooded grassland are the characteristic vegetation types of the study area (Friis et al., 2011). The economy of the local people is mainly based on subsistence agriculture where mixed farming is a common practice (KTZARD, 2011). Although Ethiop. J. Biol. Sci., 17(Suppl.): 133–161, 2018 137 enset is a staple crop to most people, other crop types such as cereals, pulses, and vegetables are grown in enset cultivation systems. Moreover, the local people are engaged in livestock rearing. The waste from livestock and other household wastes serve as organic fertilizer for enset home gardens. Selection of study sites Agroclimate was the main factor in selecting the study sites (hereafter farmscapes). Farmscape is a landscape in which farming has largely played and does play a large role. The three traditional agroclimatic zones were determined as Dega, Weyna-Dega, and Kola following Daniel Gamachu (1977). In total, 12 farmscapes were selected from the study area. At each farmscape, 15 sampling sites (farmlands owned by households or HHs) were randomly sampled, making the total sampling sites 180. Among the selected 180 HHs, 156 (87%) were male headed and 24 (13%) were female headed. But the percentage of female participants in the interview was 47% (n=85) of the total respondents. The wealth status of the farmers was determined with the help of kebele or peasant association development agents, community leaders and elders based on the context of the local farmland size, livestock holding, amount of crop production and the engagement of some off-farm activities. Data collection on enset landraces The total enset landrace composition was determined by making a presence- or-absence record in farms of each sampled HH. In order to investigate the pattern of diversity that exists in the area, the identification of enset landrace and recording of basic information such as uses of landraces, farmers’ preferences, criterion for landraces identification, and the cultural management practices were recorded with the help of farmers. There is no standard descriptor relevant for the identification of enset landraces (Kefale Alemu and Sandford, 1996; Eyasu Elias, 2003). Thus, farmers’ identification and the response were complemented by identifying landraces using the color (pseudostem, midrib and leaf petiole) of the plant at adult stage. Finally, field notes and photographs of plants representing the different landraces were taken, and the identification of landraces and listing of the names was conducted by consulting scientific literatures following previous scholars (Del Greco et al., 2007).

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The characters of enset landraces that were used to evaluate the knowledge of farmers on use values were based on qualities of bulla, amicho (hamicho), kocho, taste, storability, yield, earliness, fiber, fodder and medicinal values. Additional characters used were the resistance to enset diseases like the destructive bacterial wilt/EXW (locally called Ganshoo/alloya) as well as the resistance to drought. To study the perception of 80 informants on the end uses of the enset landraces, 38 recognized enset landraces were ranked by farmers (1 = poor, 2 = intermediate, 3 = best) and converted to binary data (1 best or 0 poor). The summarized data were subjected to multidimensional preference analysis (MDPRE) to assess the possible association between enset landraces and the various attributes mentioned following Yemane Tsehaye and Fassil Kebebew (2006). Environmental and socioeconomic data Data on farm characteristics (slope, altitude, aspect, location and the farm size), HH characteristics (age, education, family size, off-farm activities, and the TLU) and market characteristics (access to road and town), the area share of enset landraces of each farm, were collected following previous researchers (Coomes and Ban, 2004; Tesfaye Abebe et al., 2006). Similarly, the data on challenges linked with enset production and cultural management were collected through Focus Group Discussion of the 10 selected key informants. Data analysis Species diversity was determined by means of species richness and species evenness. Total species richness was calculated just by counting the number of landraces in a given sampling unit. But Shannon Index (H’) and Shannon evenness (E) were used to estimate landrace diversity in the farmlands, respectively. H’ was calculated using the formula, H' = - Σ pi lnpi (Magurran, 2004), where pi is the proportion enset landraces composed of species i. E is a measure of how similar the abundance of different species are. It was calculated as the ratio of observed diversity (H') to maximum diversity (Hmax) (Pielou, 1969) using the formula, E = H'/Hmax, = H' /lnS, Where S= number of species, and ln is a natural log. Similarly, in order to examine the effects of biophysical and socioeconomic variables on enset landraces, the linear multiple regression was employed using Minitab ver 14 (Minitab Inc, 2003). ANOVA was computed to examine any significance differences in enset landraces among wealth groups and agroclimatic zones. Moreover, the multidimensional preference analysis (MDPRE) was Ethiop. J. Biol. Sci., 17(Suppl.): 133–161, 2018 139 conducted using SAS ver. 8.02 (SAS, 1999). RESULTS Characterization of enset landraces This study used farmers’ characterization as the means of detecting enset varieties, and found a total of 111 named enset landraces. The indigenous people grouped enset landraces into two based on sex. The classification into “male” and “female” does not represent the biological reproductive parts of the plant, but rather a set of qualities desired by local people. There was high significant difference (P<0.01) in enset landraces among the three economic classes, and there was also extremely significant difference among the three agroclimatic zones (P<0.001). The mean number of enset landraces in the Zone was 7.2/HH. Dega agroclimatic areas cultivate large number of enset landraces (mean = 11.5/HH) but the number of enset landraces grown in Kola areas is half of the enset grown in Dega agroclimate. Enset landraces also vary in their frequency across the zone. Poor farmers grow few numbers of landraces, and the number of enset landraces is related to the farmland size, area allocated to enset, and the size of livestock (Table 1). Table 1. Average number of farm size, enset area, and the number of enset landraces cultivated by 3 economic classes across the 3 agroclimatic zones of the study area (N = 180). Wealth Farmland Enset area No of No of landraces in Std. Total category Size (ha) (ha) livestock agroclimatic zones Dev. Dega WD* Kola

Poor 0.8 0.11 1.86 9.2 7.9 3.5 6.9a 3.9 Medium 1.9 0.23 4.6 11.4 11.2 6.3 9.7ab 3.6 Rich 3.3 0.39 12.5 13.8 10 7.5 10.4b 4.2 Average 2 0.24 6.3 ± 0.7 11.5a 9.7b 5.8c 9 3.9 WD* = Woyna Dega; letters with different superscripts are significant (P<0.05) The top 10 most frequent enset varieties are shown in Table 2. The top three most frequent enset landraces were Sisqella, Dirbo, and Gishra with frequency of 57.2, 53.5, and 47.5%, respectively. These are the male varieties. There was high significant difference (P<0.01) in the mean density of enset landraces across the farmscapes. The density of enset per hectare was 445, 1037, and 3081 for Dega, Woyna Dega, and Kola agroclimatic areas, respectively, and the mean density was 1520 (Table 3). In general, people in Kola agroclimate grow limited number of landraces but more dense in their small home gardens.

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Table 2. Frequency of the ten most widely cultivated landraces in KT Zone.

Local Abat- Sisqela Dirbo Gishra Gimbo Unjamo Laqqaqa Sebera Sheleqe Xorrore name merza Frequency 57.2 53.7 47.5 43.1 39.6 32.9 30.2 23.1 19.8 19.6 (%) Diversity in enset landraces The enset plantation area in the homegardens of the study area ranged from 0.01 to 1.25 ha with a mean of 0.24 ± 0.02 ha (Table 3) but enset plantation covers 9% of the total crop land in the study zone. The number of enset landraces per farmscapes ranged from 8 to 61 with an average of 27.3, whereas the mean Shannon diversity index (H') and evenness (E) indices were 1.84 and 0.64, respectively, in the zone. Similarly, the mean number of enset landraces at farmland level was 9 ± 3.9. But the number of enset landraces showed extremely significant difference (P<0.001) across the farmscapes. Enset landrace diversity tends to decrease down elevation (Table 3). The highest number of enset landraces, 61(55%) was recorded from farmscape 1 (A/Sadicho) where the altitude is above 2500 m asl. It had also the highest average number of enset landraces, 15.1 per farmland indicating that each farmland represents about 15% of the enset varieties in that farmscape. Furthermore, this farmscape had the highest evenness value (0.88). However, the highest landrace diversity (H’ = 2.36) was recorded from farmscape 5 in Woyna Dega agroclimate. Nonetheless, the least number of enset landraces was recorded from farmscape 10 (H/Zato), 8 and 0.93 at site and farmland level, respectively. This farmscape falls under Kola agroclimate (< 1800 m asl) where cereals are the main staple food. Due to the prevalence of sandy soils, few farmers grow enset for uses other than staple food. As a result, there were very low values of E and H’, 0.20 and 0.7, respectively (Table 3). The H’ value is below the theoretical range which signals few numbers of landraces in the sample as well as the absence of landraces in other samples. Ethiop. J. Biol. Sci., 17(Suppl.): 133–161, 2018 141

Table 3. Total and mean number of enset landraces, mean values of the Shannon (H') and the Evenness (E) indices, and enset density across the farmscapes. Farmscape Farmscape Altitude Area share Total Mean Std. Shannon Std. Evenness Enset density number Name (m) (ha) Landraces Dev Index, H' Dev Index, E (indvls/ha) 1 A/Sadicho 2619 0.39 61 15.1g 7.9 2.26a 0.03 0.88a 435 2 Kazalla 2350 0.35 20 14fg 5.1 2.18a 0.03 0.83a 236 3 Hobicho 2407 0.29 58 13.6fg 5.8 2.22a 0.02 0.85a 324 4 Sigazo 2310 0.30 18 2.7b 3.8 0.89b 0.08 0.31b 784 5 Kerekicho 2259 0.25 42 11.6ef 3.8 2.36a 0.01 0.65a 768 6 Agara 2120 0.21 22 8.7de 4.6 2.0a 0.03 0.64a 543 7 Mesafe 2126 0.37 24 7.1cd 3.1 2.16a 0.03 0.68a 476 8 Chacho 1892 0.19 25 4.2abc 1.8 1.80a 0.04 0.57a 2358 9 Kaillama 1790 0.18 15 6.2bcd 2.9 1.86a 0.03 0.76a 2535 10 H/Zato 1745 0.04 8 0.93a 2.3 0.7b 1.67 0.20b 4508 11 Ajora 1557 0.21 24 5bc 4.4 1.64a 0.05 0.52a 533 12 Soyame 1677 0.15 10 3.5b 1.4 1.90a 0.02 0.70a 4747 Average 2071 0.24 27.3 9 3.9 1.84 0.31 0.64 1520

Note: Dega agroclimate = farmscape (site) 1-4; Woyna Dega = 5-8 and Kola = 9-12.

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The use values of enset The ordination analysis performed to identify the relationships among 38 landraces in 12 farmscapes revealed that 84.5% of the total variation to have been accounted by the two dimensions or axes (1and 2) (Fig. 1). The use values with long vectors (amicho, earliness, storability, fiber, and high yield,) are useful in discriminating enset landraces. The enset landraces investigated showed a high significant variability (P<0.01) in their use values, and there was some sort of clustering of landraces, especially towards amicho, bulla, taste, and earliness. Multidimensional preference ranking analysis separated the landraces locally distinguished as ‘males’ towards negative dimension of the first axis, particularly landraces such as Gishira, Sisqella, and Unjamo. These landraces are the most frequent and dominant in the study area (Table 2). They are highly acknowledged for their fiber quality, and also claimed to have better tolerance to drought. However, they are poor in amicho and bulla quality, and fermented lately when processed for kocho. Most enset landraces were females, which yield better quality amicho and Kocho. Moreover, the quality of amicho, storability and yield are also useful in discriminating enset landraces. Thus, it is possible to state that names given to different landraces on the basis of their use values by enset-growing farmers seem consistent. Amicho, taste, and earliness were pointed roughly to the same direction, which may display similar preference patterns. It means those enset landraces that are preferred to amicho are tasty, which also ferment early if desired to process kocho. Bulla and amicho contributed more to the positive axis of the first dimension where varieties of the ‘female’ category dominated. The varieties under this dimension also overlap with their uses. For example, Itine, Woa, Woshameda, Goemorsa, and Usquruzuare known for processing a quality bulla, and also preferred to their tasty amicho. The short length of arrow for bulla shows its relatively low significance in grouping enset landraces. In general, most of the studied enset landraces were used for preparing amicho (≈ 51%), followed by bulla (50%), processing kocho (41%), and medicine (19%).

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Fig. 1. Ordination of 38 enset landraces based on the end uses obtained from multidimensional preference ranking (Note: Qualities selected for ranking were amicho, bulla, kocho, medicine, fiber, fodder, and tolerance (to drought or EXW). Medicinal use of enset Table 5 shows that twenty one enset landraces were identified for their medicinal use. Thirteen enset landraces were known to cure problems of broken bone fractures and joint displacement both in human as well as livestock. The enset landraces like Laqaqqa is used to heal the boil (a painful infected swelling). The watery liquid squeezed from the pseudostem of some varieties is boiled and the skin is washed to heal fungal disease called ulaama (Tineacorporis), e.g., Hargama and Moche. Qeqilleis uniquely a red coloured variant with abortifacient action, used to expel placenta. The management of such medicinal landraces differs in that they are planted closer to home in order to take care by supplying adequate manure, and to

144 Melesse Maryo et al. protect them from pests. Moreover, the processed enset food, called kocho is used against dysentery. Table 5. Medicinally useful enset landraces used to treat various ailments. Name of Part used Used for Ailment type enset variety Human Livestock Aganche Astra Charquwa Fello Gimbuwa Gishira The corm is cooked and fed with milk or it Bone setting Ketanne Corm Fed raw is ground , cooked and Qeniware butter is added Sebera Sheleqoma Xebare Xessa Zinke Boil Laqqaqa Corm Cooked and fed with Not common Teresseqa milk Skin fungal Oniya Pseudostem Watery liquid X problems squeezed, boiled Hargama Moche Wolagella Afterbirth Qeqille Corm Cooked and fed raw Hepatitis Unjamo fed with milk X Note: X mark indicates the absence of report in livestock. Non-medicinal use of enset Table 6 shows non-medicinal multiple uses include human food, livestock fodder and non-food uses. Enset varieties like Gishira, wojuSorphe, wojuQeqille, Aganne, and Wolanche are used to fatten cattle, mainly oxen. But all landraces are not given to cattle because informants declared that if some landraces, for instance, Qeqille are given to a pregnant cow, it results in abortion. Many of the female varieties have large amount of bulla or starch, which may deter digestion and can cause death to cattle, e.g., Buqane is not recommended. Some landraces are highly recognized by the local people. For example Bishato, Bunache and Usquruzu have high quality kocho from which injera (thin, and flat Ethiopia bread) can be made. Varieties like Abatmerza, Gimbo and Sebera are used to process a high quality kocho from which a traditional food called atakana is made. Atakana is made mainly during the Ethiopian Meskel holiday, which commemorates the finding of the true Ethiop. J. Biol. Sci., 17(Suppl.): 133–161, 2018 145

cross. Kocho is dried for a month to allow it lose its moisture. Then, it is powdered, baked on flat clay material, cooled, and spiced. Then, it is softened by adding purified butter and milk until it is made to be taken with spoon. Table 6. Some of the non-medicinal uses of enset. S. No Products of enset Uses Remark

1 Waasa (Kocho) Food Surplus for sale 2 Hamicho ( Amicho) Food Mainly for income 3 Bu'ula (Bulla) Food generation

For making ropes, tying fences, 4 Qancha (fiber) Mainly for sale builing houses, bondage, mats

Bread wrapper, serving plates, and 5 Habara (leaves) pit liners to store kocho Hofcho ( dried leaf Wrapper for butter and 6 pseudostem and sheaths) kocho Halana ( pulp from the Diaper for babies, 7 dried petioles and midribs) brusher Some female named Wesse ( all fleshy part of 8 fodder for cattle landraces, rich in bulla are adult enset) abortifacient and excluded In general, over the course of time, indigenous people in the study area have made enset production a part of their life activity. It is a food to humans, fodder to cattle, medicine to humans and livestock, a source of income, a source of useful materials (e.g., sacks, bags, mats, fiber and sieves), material for building houses and tying fences, ornamental crop around the home gardens, and its ability to reduce soil erosion are some of the important uses of enset, among others. Hence, enset is everything to indigenous people. They describe this in their proverb ‘mini xawahawessewassahalamenobaa’, meaning family issues and kocho are never bored of. That means although kocho is fed often, any one never losses interest to eating it. This shows the strong attachment of the indigenous people to enset plant. Determinants of enset landrace diversity Enset based homegardens of the study zone varied in the number and types of enset landraces they held (Table 3). Table 7 shows that the socioeconomic factor primarily off-farm activity and the physical environmental factors (i.e., elevation, access to main road and access to market) have significantly influenced the diversity of enset landraces. Other factors such as age of the HH, TLU, family size (labour force), and cultivated crops diversity did not show any significance though they were

146 Melesse Maryo et al. positively correlated to enset diversity (Table 7). However, the landrace diversity increased with decrease in distance to market. This could be related to the benefit that the local people gain by selling various enset products including enset leaves (used to bake breads) to urban areas. Challenges to enset landrace diversity and indigenous management systems The enset plant growing in small areas of the home garden is a renowned food security crop. However, most respondents confirmed that the shortage of farmland, influences of vertebrate pests and enset diseases (Fig. 3) are challenging the diversity and production of enset. The focus on fast growing cash crops by young generation is also another emergent challenge. Informants also described that fragmentation of the home garden (farm subdivision) due to large family size resulted into a shift towards short season growing crops, and avoiding less disease/pest tolerant enset landraces. There is a prudent interaction between enset and livestock in enset farming areas particularly in the highlands where enset serves as a source of fodder, and livestock provide manure to fertilize enset fields. Eighty six percent of farmers stated that there is a shortage of grazing land as well as arable land, which in turn tend to limit livestock number. In addition, about 52% of the farmers described that enset landraces faced difficulties from wild animal pests and diseases, mainly porcupine (79%), Aloya/Gansho (EXW) (9%) (Fig. 3B), the disease called Zi’iraor sheath rot (8%) (Fig. 3A), mealy bug (5%) and the mole rat (4%). Sixty percent of the informants confirmed that porcupine causes great loss of various enset varieties that are highly preferred to edible corm (e.g., Astra, Aganne, Leqqaqa, and Oniya), medicinal values, quality bulla and Kocho. As a result, many farmers abandoned cultivating highly preferred varieties for they are easily damaged by porcupine. However, there are various methods that indigenous people developed to protect enset from pests and diseases. For instance, methods to protect porcupine include repelling by smoking bones in the crop fields, building stone bench terraces around crop field, filling porcupine holes, deep digging around its den, and adding manure around the victim enset varieties. Farmers also suggested the significance of cooperation of local communities, including neighbour peasant association in the protection of this pest. Ethiop. J. Biol. Sci., 17(Suppl.): 133–161, 2018 147

Table 7. Multiple linear regression between number of enset landraces, socio-economic and biophysical factors (n=180) (Pearson correlation).

Off Farm Enset Family Crop Access Access to Variables Age Education farm TLU Aspect Slope Elevation land diversity size diversity to road market activity Size Enset diversity _ 0.05 0.01 0.06 -0.18* 0.02 0.07 0.1 0.18 0.68** -0.15** -0.45** 0.1 Age _ -0.39** 0.28** -0.09 0.31** 0.24** 0.04 -0.17* 0.04 0.02 0.11 0.3**

Education _ 0.04 0.27** 0.1 -0.09 0.07 0.1 0.05 -0.14 -0.05 0.04

Family size _ -0.04 0.37** 0.16* 0.07 -0.01 -0.03 0.01 0.01 0.43**

Off farm _ 0.19** -0.03 0.12 0.03 -0.01 -0.08 0.08 -0.1 activity TLU _ 0.38** 0.1 -0.2** -0.09 0.07 0.14 0.71**

Crop diversity _ 0.06 -0.2** -0.11 0.2** 0.22** 0.31**

Aspect _ 0.08 0.07 0.04 0.02 0.05

Slope _ 0.13 -0.20** -0.17** -0.15*

Elevation _ -0.16** -0.53** -0.07

Access to road _ 0.45** 0.05

Access to _ 0 market Farmland size _

*. Correlation is significant at the 0.05 level (2-tailed). **. Correlation is significant at the 0.01 level (2-tailed).

Note: The tropical livestock unit (TLU)) is commonly taken to be an animal of 250 kg live weight. TLU conversion factors constitute a compromise between different common practices. 1 TLU= 250kg. Accordingly Bull = 1.1, calves = 0.2, Chickens = 0.01, Cows (cross) = 1.2, Cows (local) = 0.8, Donkeys = 0.5, Goats/ sheep = 0.1, Heifers = 0.5, Horses/mule = 0.8, and Immature males 0.6.

Source: (Jahnke, 1982)

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Traditional methods that are used to prevent the mole rat include the removal of large grassy crop field margins, trapping, and flooding the mixture of cow and horse dung into its hole. Furthermore, highly recognized enset varieties are planted very close to the home meant to protect from pests. Informants also discussed that though not regularly practiced by all, knowledgeable indigenous people 1). Grow some plants like Pycnostachys abyssinica and Canna indica near enset plant that is affected by EXW. During the field work, some recovered landraces were observed after planting this species; 2). Plant healthy, disease-free enset suckers, and use clean farm tools, and 3). Remove infected enset from the area and rotate cereal crops to avoid bacterial recycling. But very few farmers use the combination of these methods.

Fig. 3. Commonly observed enset diseases (Photos by Melesse Maryo). A) Zi’ira (sheath rot) forms a freckle like spots that coalesce to form a big one, the leaf sheaths of the pseudostem dries up. It is caused by fungal sp. A plant has an opportunity to recover), B) Aloyaa/Ganshua (EXW) kills a plant. DISCUSSION Indigenous knowledge and enset diversity Although folk botanical nomenclature is not guided by a set of written rules, there are prominent similarities in the way that plants are named by indigenous people around the world as described by Martin (1995). The Ethiop. J. Biol. Sci., 17(Suppl.): 133–161, 2018 149 classification of enset varieties into male and female based on certain farmer based characterizing qualities such as fiber quality and drought tolerance is in agreement with traditional knowledge from Bonga (Yemane Tsehaye and Fassil Kebebew, 2006) and Kaffa Shaka (Almaz Negash, 2001). This may show either independent development of similar cultures or the diffusion of cultures or both for the management of enset over years. The local people, mainly women provide great care and treatment to female landraces because 1) The varieties are more susceptible to drought, pest and EXW; 2) They are early maturing and can be harvested any time for the household consumption among poor families; and 3) Their products are tasty and have relatively high price. This agrees with earlier study on enset (Asnakech Woldetensaye, 1997). Farmers sustained diverse range of enset landraces on their home gardens for the landraces could differ in their uses. This agrees with the report of Eyasu Elias (2003) from Ethiopia. The most frequent enset types were male landraces. Similar observation was reported from Sidama by Bizuayehu Tesfaye (2008). The dominance of male enset landraces such as Sisqella, Dirbo and Gishira across the studied agroclimatic zones may be linked with the low susceptibility to diseases and drought conditions, low preference by wild pest animals, and their uses both for human and livestock. Zippel (2005) also stated that farmers in Ethiopia always grow some less favoured landraces that withstand severe weather conditions. Enset landraces are resistant to drought and disease, which seems a means to cope with uncertain environmental conditions. This was explained by Admasu Tsegaye and Struik (2002) that in a relatively dense enset plantation the leaf canopy conserves soil moisture, suppresses weed growth and reduces organic matter decomposition by reducing soil temperature besides full use of the land. Enset is widely spaced in Dega and Woyna Dega to avoid competition, and enhance leaf branching meant for fodder use and thickness of pseudostem for kocho processing. More than four decades ago, Taye Bezuneh and Asrat Feleke (1966) reported 70 enset landraces from the whole Ethiopia. Our finding showed 111 enset landraces, which is the highest record documented so far from zonal level in the country. Such deviation could be attributed due to the evolution of new landraces or the method of sampling or both. Other previous reports on enset landrace diversity in the country include 78 from Ari (Shigeta, 1990), 65 from Kaffa Shaka (Almaz Negash, 2001), 42 from Sidama (Tesfaye Abebe et al., 2010), 70 from Kafa (Feleke Woldeyes,

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2011), 105 from Gamo Gofa (Sabura Shara and Mulugeta Diro, 2012), and recently total of 66 folk landraces from Kambatta Tembaro Zone (Zerihun Yemataw et al., 2016b). The richness of enset landraces in the current study when compared with the previous studies might be due to the agroclimate condition where mid and highland areas comprise 92%, which are appropriate for enset cultivation. The stratified sampling method that involved different agroclimatic zones as well as different wealth categories probably has also contributed to the high landrace diversity record of the current study. The study zone is bordered by Wolayita, Hadiya, and Dawro zones where the improved infrastructure might have permitted the local people to exchange landraces (sprouts or suckers forms) over the long distances. The exchange of enset landraces from the neighboring ethnic groups and peoples culture to use the diversity for different purpose perhaps made the area to be one of the richest in enset landrace diversity. The significance of the use value based criteria was suggested for landrace diversity maintenance and management (Zerihun Yemataw et al., 2016). Enset landrace exchange was reported from Sidama by Bizuayehu Tesfaye and Lǘdders (2003). New landraces can also be introduced through trade (Zippel, 2005). Enset landraces are exchanged mostly at sima stage (a year-old sucker) or mother corm pieces. The similarity in enset landrace names among different enset cultivating ethnic groups of southern Ethiopia is shown in Table 4. The similarity in names with or without slight modification may indicate the landrace exchange between different ethnic groups. The mean number of enset landraces identified at farm level in the present study was nine but Zerihun Yemataw et al. (2016b) reported 7.8 from the same study zone. The difference could be chiefly associated with sampling method employed. The corresponding figure from Sidama (Tesfaye Abebe et al., 2010) and Gamo Gofa (Sabura Shara and Mulugeta Diro, 2012) was 6 and 7.4, respectively. This shows that farmers of the study area maintain fairly considerable number of enset landraces at individual farmland level. The finding also exhibited that the highest number of enset landraces was recorded from farmscape 1 (AnchaSadicho) with altitude > 2500m asl, and it had also the highest evenness value, showing that the farmscape was characterized by a large number of landraces which are better distributed equally in most sample households of the farmscape.

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In general, the current survey can offer information about the level of existing enset landrace diversity and the distribution in KT Zone. It also may serve as a baseline data to allow monitoring of future genetic erosion. The study area differs both in the number and type of landraces across the agroclimatic zones. Farmers in lowland areas mostly cultivate landraces tolerant to drought and disease. However, in highland areas highly diverse enset landraces over relatively wider areas are grown. This finding is in agreement with the work of Asnakech Woldetensaye (1997). Since highlanders grow diverse enset landraces, they use to feed various enset products or the products of enset-cereal mix. This may show the maintenance of enset diversity through use. Benefits from enset Eyasu Elias (2003) identified seven medicinal landraces from Wolaita. Similarly, Admasu Tsegaye (2002) reported three medicinal landraces from Kaffa-Shaka Zone and twelve from Hadiya Zone. The other study conducted in Gurage identified eleven medicinal varieties (Worku Nida, 1996). The high number of enset medicinal varieties (total number = 21) of this study area may indicate the knowledge that indigenous people of KT Zone had developed over the course of time towards the efficient exploitation of the diverse enset landraces. Studies confirmed that enset is rich in calcium, magnesium, potassium, and iron. The concentration of calcium is 36,100 – 39,100 μg/g on dry weight basis (Ayalew Debebe, 2006). Similar study showed that enset products are rich in calcium, and are free of heavy metals (Cd and Pb) (Minaleshewa Atlabachew, 2007). Presumably, the high calcium content, common among certain enset types, must be the quality that contributes to the preference of enset in healing fractured bones. Similarly, a chemical substance called phenylphenalenone, which has antitumour, antibacterial, nematicidic and antifungal activity has been reported from some enset landraces (Hölscher and Schneider, 1998). This indicates that more has to be done on the analysis of nutrient contents of various landraces that may help for the development of food quality as well as modern medicinal treatment. According to Dessalegn Rahmato (1996), during environmental hazards and famine, enset can be harvested and consumed before it is fully mature, though the quality of food may be poor. Such qualities of enset plant permitted enset growing regions to suffer less during famine periods in the past.

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DETERMINANTS OF ENSET DIVERSITY Elevation was the only variable that positively related to the enset landrace diversity. Thus, there was a strong and positive correlation of the number of enset landraces with altitude (Fig. 2). The result is consistent with the study in Sidama (Bizuayehu Tesfaye and Lṻdders, 2003). This could be due to relatively optimum temperature and moisture, as well as fertile and well- drained loamy soils in highland areas. For optimum growth, enset plant requires an annual average rainfall of 1100-1500 mm, and a mean temperature of 16-20°C (Taye Bezuneh and Asrat Feleke, 1966). They also described that E. ventricosum occurs at altitude from 1500-3100m asl. Similarly, the study zone falls under these ranges.

Fig. 2. The relationship between elevation and number of enset landraces in KT Zone. Our result showed that landrace diversity increased with decrease in distance to market. The finding contrasts with the hypothesis that associates market isolation with higher levels of crop diversity (Van Dusen and Taylor, Ethiop. J. Biol. Sci., 17(Suppl.): 133–161, 2018 153

2005; Winters et al., 2006). But other studies reported that farmers cultivating in close proximity to major market centers maintain relatively high levels of crop diversity (Perales et al., 2003; Sthapit and Shrestha, 2006). On the other hand, enset landrace diversity found to decrease with increase in exogenous income (e.g., trading). This finding is consistent with the report by Brandt et al. (1997). Enset diversity decreases with increase in off- farm activity. This could be because enset cultivation is an incessant labour seeking activity. Any interruption in enset growing activities may affect its diversity and production. Another worker also affirmed that exogenous income could contribute to significant losses in crop genetic resources (Isakson, 2007). It was shown that the growing prevalence of exogenous income undermined the cultivation of maize genetic diversity in Mexico (Fitting, 2006). Van Dusen and Taylor (2005) also discussed that households located in communities where a greater percentage of agricultural tasks are performed by hired labour tend to plant fewer crop varieties. Finally, there was a remarkable correlation between on-farm diversity of enset landraces and the house hold characteristics of the better off (Table 1). Wealthy farmers grow more enset landraces which is in accord with an earlier finding in south western Ethiopia (Almaz Negash and Niehof, 2004). This could be attributed to the possession of large landholding. They also have an aptitude to manage environmental risks that might affect enset production as described by Isakson (2007). That means the status of these households to maintain the sanitary measures as a means to control enset disease plus methods used to protect enset pests might be significantly higher. Problems related to enset management Our study indicated that the scarcity of farmland influenced enset landrace diversity. The study on Gamo highland (Cartledge, 1999) also agrees with this finding. Enset farming requires high fertilizer application, which can only derived from livestock manure. Limiting the livestock number per household in turn affects the enset farming system (Brandt et al., 1997). Brandt et al. (1997) also expressed that the decrease in livestock and manure may cause reductions in yields and soil fertility, thereby reducing the long- term sustainability of the enset system. Likewise, the shortage of agricultural land was stated as a challenges to enset production that caused the young generation to rely on cash crops other than enset This was also described by other studies (Almaz Negash, 2001; German et al., 2012).

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Enset diseases and pests were more common in the highland areas but mealy bug (Fig. 4a) was dominant in the enset fields where moisture is less available. It was reported that sheath rot in enset is caused by bacteria (Quimio, 1991). Fifty five percent of the farmers affirmed that among wild mammalian pests that damage enset, porcupine stood the first, which is followed by mole rat. Previous study also indicated that 97% of the farmers reported attack to enset by pest like porcupines and moles to be the leading followed by EXW (Shiferaw Tesfaye, 1996). Other studies also emphasized that vertebrate pests and EXW to be threats to enset production (Million Tadesse et al., 2003; Bizuayehu Tesfaye, 2008; Abrham Shumbulo et al., 2012). More recently, enset diseases and enset damaging wild animals were also reported as the major production constraints in the Gamo highlands in Ethiopia (Teshome Yirgu, 2016).

Fig. 4. Enset plantation loss due to mealy bug and EXW disease. Cultural sanitary activities against enset disease and pests management methods used by some local people should be integrated into scientific approaches to effect sustainability of enset landrace diversity. Disinfecting farming tools, uprooting and burning the infected enset plants, keeping fields and surrounding areas free of weeds, exposing the soil during dry season prior to planting, proper spacing, avoiding overflow of water from Ethiop. J. Biol. Sci., 17(Suppl.): 133–161, 2018 155 infested to uninfected fields, controlling porcupine, mole rat, and other domestic animals from browsing, use of clean planting materials, rotation of crops, and use of resistant/tolerant landraces were suggested as the management package used and promoted country in the past (Zerihun Yemataw et al., 2016 ). Similarly, one study confirmed positive effect of Pychnostachis abyssinica against the parasitic bacteria (Kidist Bobosha, 2003). Therefore, these are the indications of the need of scientific investigation of the indigenous knowledge and practices for the future controlling measures. Informants claimed that there is little or no extension package that enables development workers at kebele level to benefit farmers in managing enset diversity. It was stated that subsequent training given to farmers and extension workers enhance farmers’ understanding about Enset Xanthomonas Wilt (EXW) means of transmission and ultimately disease prevention and control options (Zerihun Yemataw et al., 2016). CONCLUSON Kambatta people possess rich traditional knowledge on enset landrace diversity, namely naming, using the diversity for different purposes, conserving, etc enset landraces. This is associated with people’s rich culture of using enset landraces for various uses developed through ages. For instances, about twenty percent of all the identified landraces were used to treat various human and livestock ailments, which is the highest report in the country. The exchange of planting materials with neighbouring ethnic groups, and the pertinent agroclimate affect growing enset. The diversity of enset landraces is directly correlated with socioeconomic aspects of households such as the size of farmland, family size and the size of tropical livestock units. However, the diversity was found to increase with altitude ranging from 2000 to 2500 m a.s.l. whereas the density of enset landraces was increases with decrease in altitude. This is because at higher altitudinal areas there is a wider spacing between enset crops to enhance leaf branching for animal fodder as lowlanders increase the density to counteract the loss due to unfavorable environmental conditions. Nonetheless, there are significance challenges that could hamper enset diversity and its productivity, particularly, scarcity of farmland and young farmers trend to focus on short season growing crops and other cash crops, continuous land fragmentation across generation line, enset bacterial wilt, mainly in highland areas, wild pests such as porcupine, mole rat, and mealy bug.

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Many traditional methods of mammalian pest management method include flooding a water mixed of cattle manure, and removing grassy area from crop field that may encourage mole rat multiplication. Moreover, some plant species such Pycnostachys abyssinica and Canna indica were found effective against the impact of Xanthomonas campestris when grown near to enset plant. Thus, the biocontrolling activities of such plants should be evaluated. Similarly, phytochemical analysis of the examined landraces of medicinal significance should be assessed to recognize their medicinal properties. Still, there is need to encourage livelihood diversification among farmers with very small plots of farmland. The kebele extension workers in enset growing areas should have a special training program that capitalizes on enset diversity and its management in order to assist farmers to apply integrated methods in protecting enset landraces against enset disease and pests, maintenance of enset diversity and maximizing enset productivity. They also need to have a mandate to facilitate the exchange of better clones/varieties within peasant associations and peasant associations to maintain landrace diversity. In order to protect and conserve the diversity scholars in ethnobotany, microbiology and genetics should work together for a realistic workable solution. Appropriate attention should be given by the Ministry of Agriculture and Natural Resources to incorporate enset crop in the current extension system. The extension workers who will train in enset agriculture will help farmers in the maintenance of landraces diversity, in pest and disease controlling activities. ACKNOWLEDGEMENTS We are very much grateful to local authorities, Peasant Association leaders and the local healers in Kembatta Tembaro Zone. Without their contribution, this study would have been impossible. We would also like to thank Addis Ababa University for the grant to conduct PhD study. REFERENCES Abrham Shumbulo, Yishak Gecho and Melese Tora (2012). Diversity, challenges and potentials of enset (Ensete ventricosum) production: In case of Offa Woreda, Wolaita Zone, Southern Ethiopia. Food Sci. Qual. Manage.7: 24–31. Admasu Tsegaye (2002). On Indigenous Production, Genetic Diversity and Crop Ecology of Enset (Ensete ventricosum (Welw.) Cheesman). Ph.D. Thesis, Wageningen University, Wageningen. Admasu Tsegaye and Struik, P.C. (2002). Analysis of enset (Ensete ventricosum) indigenous production methods and farm-based biodiversity in major enset- growing regions of southern Ethiopia. Exp. Agric. 38(3): 291–315. Ethiop. J. Biol. Sci., 17(Suppl.): 133–161, 2018 157

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Ethiop. J. Biol. Sci. 17(Suppl.): 163–189, 2018 © The Biological Society of Ethiopia, 2018 ISSN: 1819-8678 ACHIEVEMENTS, EXPERIENCES AND STRATEGIES ON ENSET (ENSETE VENTRICOSUM (WELW.) CHEESMAN) RESEARCH IN ETHIOPIA

Zerihun Yemataw1,*, Sadik Muzemil1, Agedew Bekele2 and Eshetu Derso3

ABSTRACT: Enset (Ensete ventricosum (Welw.) Cheesman) is a perennial, herbaceous and monocarpic crop belonging to the family Musaceae. Enset based farming is an indigenous and sustainable agricultural system in Ethiopia with a total of 312,171.98 hectares of land under cultivation. The production and productivity of enset is affected by various biotic and abiotic stresses. Enset research activities have been initiated since the 1970s at different institutions. Currently, the research is nationally coordinated by Areka Agricultural Research Centre (AARC). Accordingly, the centre has been coordinating more than fifty research activities on five research objectives. The objective of this paper was to review the status of enset research and development, and provide strategies for transforming the sector. With regard to the crop improvement, the following have been sorted out: clonal identity using farmers’ classification, collection and maintenance of enset germplasm, morphological and molecular characterization of enset clone, evaluation of enset varieties for drought tolerance and best quality and yield of kocho and amicho. Regarding the agronomy part, studies on comparison of whole, halved and quartered corms for planting, frequency of transplanting, spacing for planting enset on permanent field and soil fertility management have been carried out. Other attempts were also made on epidemiology and pathogenicity of EBW, and identification and control of other pests and diseases such as root mealy bug, and identification of some tolerant clones. Technologies on enset processing were developed such as: enset decorticator, squeezer and grater and all these findings and technologies have been well documented in the form of manuals, posters and leaflet forms and distributed to stakeholders and end users across enset producing zones. In order to sustain the benefits of the research and development, the project is organizing training programs and extension activities to sensitize and enhance capacity building of the farmers.

Key words/phrases: Diversity, Enset, Enset Bacterial Wilt (EBW), Genetic resources, Strategies.

1 Southern Agricultural Research Institute, Areka Agricultural Research Centre, P.O. Box 79, Areka, Ethiopia. E- mail: [email protected] 2Southern Agricultural Research Institute, P.O. Box 06, Hawassa, Ethiopia. 3 Ethiopian Institute of Agricultural Research, P.O. Box 2003, Addis Ababa, Ethiopia. *Author to whom all correspondence should be addressed

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INTRODUCTION Enset is the most widely used staple food crop for millions of people living in South and southwestern Ethiopia. It plays a central role in the economic life of the South and southwestern people (Brandt et al., 1997). According to CSA (2011), a total of 312,171.98 hectares of land was under enset in the country, taking up about 2.30% land area covered by all crops at country level. The number of enset trees to be harvested, in 2015 was estimated to be 112,522,152. Thus, the total produce in the form of amicho, kocho, and bulla is 23,821,849.47 quintals, 28,329,103.94 quintals and 950,414.35 quintals, respectively (CSA, 2015). The average yield of refined enset product (kocho) ranges from 7 to 12 tons ha-1 year-1. The amount of food attainable from 50-60 enset plants per year could provide enough food for an average family of 5-6 persons (Almaz Negash, 2001). Enset cultivation also protects the soil from erosion and runoff, it serves as shade and improves the microclimate for the undergrowth, and the litter from the leaves and other parts improve soil fertility (Lee and Zawdie, 1997). Research conducted on continuously enset- cultivated fields showed a higher soil nutrient status than any other fields covered with other cereal crops indicating that enset cultivation is a sustainable system with regard to maintaining soil fertility (Asnaketch Woldetensaye, 1997). Enset research was started around the late 1960s at Debre Zeit Research Centre where some varietal evaluation for yield and bacterial wilt were conducted. Since the 1970’s diverse research activities have been initiated by different researchers at different institutions. Accordingly, in 1972/73 enset clones were collected from different enset growing areas and established at Holetta Research Centre. In 1976 this collection was taken to Wolaita Agricultural Development Unit (WADU) in order to undertake variety and agronomic trials, but in early 1980s enset research in WADU was terminated in 1980. Development of enset processing devices have been developed and introduced to users at Nazreth Research Centre since1977. In 1986 Areka Research Centre was established mainly for enset agronomy research. At the same time, trials have been started at Awasa Research Centre on enset pathology and entomology. Currently, some enset research activities are being carried out at some higher learning institutions. At present, Areka Agricultural Centre (AARC) is mandated to coordinate enset research programs across federal and regional research centres. Over the years, considerable achievements have been made in generation of new

Ethiop. J. Biol. Sci., 17(Suppl.): 163–189, 2018 165 information on enset, development of improved varieties, management practices, and promotion of improved technologies. These achievements were well documented and major gaps were identified through two consecutive international and national enset workshops carried out in 1997 (Tsedeke Abate, 1997) and 2010 (Mohammed Yesuf and Tariku Hunduma, 2012). The information contributed a lot to overcome different problems related to production and productivity of the sector. However, the ever- increasing challenges such as demand for more food, and other needs of the growing population against the changing and variability of the climate, emerging, new pests and diseases, necessitate a fundamental change in formulating and implementing agricultural research. The objective of this paper is to review the status of enset research and develop and provide strategies for transforming the sector in the country. THE PROGRESS OF ACTIVITIES AT THE NATIONAL ENSET RESEARCH PROGRAM The previous findings of the research activities were published at the proceedings of the International and National workshops on Enset (Tsedeke Abate, 1997; Mohammed Yesuf and Tariku Hunduma, 2012). This paper presents a review on research outputs on enset by the National Enset Research Program before and after the two workshops. Research achievements on enset breeding Understanding on-farm diversity management Understanding the diversity of farmer varieties together with the knowledge of the traditional farmers is used to develop a guide map for identifying and collecting enset varieties for further breeding work. Accordingly, a number of farmers’ varieties were identified from the southern parts of the country since the 1990’s (Table 1). Consequently, it was recognized that indigenous skills documented on the dispersion of enset diversity and the local knowledge base is central for in situ conservation of enset diversity on-farm and for the elaboration of conservation strategies. High landrace diversity in the country may indicate extended periods of enset cultivation and a more subsistence form of production.

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Table 1. Number of farmer varieties recorded by different authors in major enset producing areas of Ethiopia. Number of No farmers’ varieties Study sites Information source 1 76 South Omo (Ari) Shigeta (1990) 2 158 Dawro, Gamo Goffa and Wolaita Kefale Alemu and Sandford (1996) 3 146 Keffa-Sheka, Sidama, Hadiya and Wolaita Almaz Negash (2001) 4 166 Hadiya, Sidama and Wolaita Admasu Tsegaye (2002) 5 79 Sidama Bizuayehu Tesfaye (2002) 6 111 9 different geographical sites (Wolkite, Genet Birmeta (2004) Setunae, Seltae, Bonga, Shonae, Worka, Answae, Wondo, Chencha) 7 42 Kaffa Yemane Tsehaye and Fassil Kebebew (2006) 8 218 7 different zones (Dawro, Gamo Goffa, Zerihun Yemataw et al. (2014) Gurage, Hadiya, Kembata Tembaro, Sidama and Wolaita ) 9 67 Wolaita Temesgen Magule et al. (2014) 10 312 8 different zones (Dawro, Gedeo, Gurage, Zerihun Yemataw et al. (2016a) Hadiya, Kembata Tembaro, Sidama, Silte and Wolaita ) Acquisition and ex situ conservation of enset germplasm Ex situ conservation of plant genetic resources in gene banks is used to conserve the existing genetic diversity of cultivated species with their infra- specific taxa and wild species of potential use outside agro-ecosystems (Alvarez et al., 2005). In 1986 Areka Research Centre was established mainly for enset research and since then agronomy trials have been carried out for the improvement of enset varieties. Over the years, new information was generated on enset and improved varieties, technologies and management practices were developed and introduced to end users. Accordingly, attempts were made to collect and preserve all the possible enset germplasm in Ethiopia. Currently a total of 623 enset clones/cultivars have been collected and conserved ex situ by the Southern Agricultural Research Institute of Areka Agricultural Research Centre (Mikias Yeshitla and Zerihun Yemataw, 2012) from 12 major enset growing areas of Ethiopia. These were 94, 93, 71, 43, 49, 44, 49, 35, 27, 29, 57 and 32 enset accessions from Kembata/Hadiya, Dawro/Waka, Gamo/Gofa, Wolayta, Sidamo, Guragie, Yem, West Shewa/Southwest Shewa, East Shewa, Kaffa, Sheka, and Jimma, respectively. Yet, not all farmer varieties from all enset growing regions are sufficiently collected and conserved.

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Variety identification and evaluation Agro-morphological characterization Enset exhibits a wide array of agro-morphological polymorphism. Numerous clonally stable traits are being used as markers for varietal identification and assessment of genetic diversity. Characterization of the germplasm of domesticated enset were conducted using morphological traits (Endale Tabogie, 1997; Mikias Yeshitla and Mulugeta Diro, 2009; Zerihun Yemataw et al., 2012a). A great deal of variability exists in quantitative and qualitative morphological, growth and yield traits among enset clones, such as maturity, kocho and bulla yield, plant height, plant pigmentation, midrib colour, petiole colour, and disease reaction (Endale Tabogie, 1997; Zerihun Yemataw et al., 2012a). However, a well-established taxonomic classification and descriptor list are still lacking, and necessitates development of well-established descriptors to understand the nature of the interaction and relationships between genetic, physiological, morphological and physico-chemical characters, in order to employ intensive selection criteria effectively and efficiently. Molecular characterization Molecular markers are important tools to analyse genetic diversity and evolutionary relationships among and within germplasm accessions in many crop species. They are useful DNA techniques that complement morphological and physiological characterization of cultivars since they are found in the whole genome, independent of plant tissue, influence of environmental and management practices and allow cultivar identification (Manifesto et al., 2001; Altintas et al., 2008). To this end, genetic variability of enset were investigated using Amplified Fragment Length Polymorphism (AFLP) (Almaz Negash, 2001), Random Amplified Polymorphic DNA (RAPD) (Genet Birmeta, 2004), Inter simple sequence repeats (ISSRs) (Dagmawit Chombie and Endashaw Bekele, 2011) and Simple Sequence Repeat (SSR) (Temesgen Magule et al., 2015) genetic markers. These works revealed a reasonable amount of variability within cultivated populations. Moreover, partitioning the existing genetic diversity within and among populations of enset also showed higher diversity within populations in many of the studies. Currently, there is a fingerprint work at Exeter University using single nucleotide polymorphisms (SNP) markers. These markers were developed by Areka ARC selected from the largest set of enset clones (458 clones)

168 Zerihun Yemataw et al. collected from the national core samples. Based on the analysis using various molecular markers, the study confirmed the long tradition of extensive seed-sucker exchange between enset cultivating communities in Ethiopia and these markers can also be applied to marker-assisted breeding to improve the productivity of enset. In another effort, an in vitro propagation of enset showed that the method is critical to conserve germplasm and propagation of virus and bacteria free plantlets. To this effect, research has been initiated to develop efficient micro-propagation and transformation methods for enset that can be used to disseminate healthy clones and improve the productivity of the crop. Overall, biotechnology and genomic tools are used to address production and processing challenges in enset at various institutions with limited and unsustainable funding. However, the recently available genome-wide sequence data on enset could accelerate enset research and crop improvement by identifying single nucleotide polymorphisms (SNPs) that might serve as molecular markers for marker-assisted breeding. Evaluation of enset varieties for different uses The goal of Enset Research Program is to enhance food security and income of enset farming communities through increased production and by improving quality of enset through efficient development of improved and sustainable technologies. The program based in Areka in Wolaita zone had a progressive result for variety selection for kocho, amicho yield and quality and EBW disease-tolerant varieties following a multi-year program of selection and a multi-location testing. A. Evaluation for kocho The program released six selected varieties for better kocho yield and quality. The varieties are Yanbule, Gewada and Endale (early maturing - 3 to 4 years) and Kelisa, Zerita and Mesena (late maturing - 4 to 5 years). The average kocho yield of the released enset varieties was 10 to 31 tons ha-1 year-1 (Table 2) (Mikias Yeshitla and Zerihun Yemataw, 2012). B. Evaluation for amicho An attempt was also made to select a variety for amicho based on corm yield and quality. Four varieties have been selected and submitted for verification for release purpose (Table 3) (Zerihun Yemataw et al., 2016b).

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Table 2. Average quantitative values of the six released enset varieties. Variety name Trait YANBULE GEWADA ENDALE KELISA ZERITA MESENA Pseudostem 2.35 1.72 1.98 1.6 1.66 1.58 height (m) Pseudostem 1.44 1.22 1.3 1.27 1.32 1.13 circumference (m) Leaf length (m) 4.9 4.1 4.33 3.6 3.99 3.52 Leaf width (m) 1.1 0.9 0.88 0.84 0.85 0.84 Leaf number 12 11 11 11 12 11 Unsqueezed 31.49 22.75 26.16 23.13 24.58 19.81 kocho (t/h/y) Squeezed kocho 21.12 15.13 17.47 15.39 16.39 13.12 (t/h/y) Source: Mikias Yeshitla and Zerihun Yemataw (2012) Table 3. Average values for plant growth and yield traits of highly performing enset cultivars evaluated across two locations. Cultivar CORM PH PSH PSC LL LW LN C C CL name YLD Chohot 4.07 1 1.21 2.97 0.61 15.37 0.71 0.34 23.29 Ashakit 3.1 0.71 1.17 2.26 0.58 15.87 0.75 0.32 20.13 Bose 3.78 0.85 1.22 2.79 0.67 12.37 0.74 0.27 19.66 Gazner 3.04 0.7 0.96 2.21 0.56 12.87 0.69 0.25 18.53 PH=Plant height, PSH=Pseudostem height, PSC=Pseudostem circumference, LL=Leaf length, LW=Leaf width, LN=Leaf number, CC= Corm circumference, CL= corm length, CORMYLD = Corm yield per hectare per year (Source: Zerihun Yemataw et al., 2016b) Development of yield estimation models Attempts were made to develop regression model which non-destructively, predicts yield of enset with better precision and simplifying yield evaluation in experiments and also overcomes the difficulties in estimating kocho yield for enset production in the different regions of the country. Mikias Yeshitla (2014) tried to estimate the yield of enset by considering different enset clones and large number of samples and the contribution of all the vegetative parameters as independent variables. The experiment was carried out at Areka Agricultural Research on-station site on a total number of 328 enset clones. Accordingly, plant height and pseudostem circumference were the best non-destructive enset kocho yield predictors. The R2 value for estimating fermented un-squeezed kocho yield was about 0.78 with the equation FUNK= -26.12 + 5.43 PH + 20.05 PSC describing the relationship of fermented un-squeezed kocho as a function of enset plant height and pseudostem circumference measurements. However, the employment of developed enset yield estimation model is limited to the few kocho sample clones collected from one location; models for bulla,

170 Zerihun Yemataw et al. amicho and fiber yield were not developed. Therefore, models accounting the inter-varietal, age group, agro-ecological, and harvesting time differences should be developed to the non-destructive prediction yield model of enset plant. Research and development experience in enset agronomy Cultivated and wild species of enset produces seeds after a long juvenile period. Taye Bizuneh and Asrat Feleke (1966) proved that enset can be propagated through botanical seeds. This study may help in getting different varieties which is not very common in vegetatively propagated crops. However, the germination potential of these seeds is very low because of mechanical seed dormancy imposed by hard seed coat where an embryo is kept between hard micropylar collars (Mulugeta Diro and Admasu Tsegaye, 2012). Therefore, the plant is usually multiplied vegetatively using whole or split corms and grown as clones (Mulugeta Diro and Admasu Tsegaye, 2012). Age of parent plants used for sucker production is between two and six years but usually varies from place to place. Studies were undertaken to evaluate the influence of age of parent corms on number and vigour of suckers at Areka Agricultural Research Centre (1994-1995) using one to five year old corms of Hal’a clones (Mulugeta Diro et al., 2001). The result showed that corms of all age group gave rise to suckers (Fig. 1). Considering the life cycle of enset crop, two to three year old parent corms can be used for sucker production. Comparison of different corm types, stemmed from farmers’ practices, was carried out at Areka Research Centre (Mulugta Diro et al., 2002). Whole, halved and quartered corms were compared (Fig. 2) for number and vigor of sucker production. Terefe Belehu et al. (1994) showed that the use of whole corm (whole and split) reduced emergence by three fold compared to use of half corm. However, halved corms resulted in vigor and more number of suckers when parent corms were uprooted, apical bud removed and planted (Table 4) (Mulugeta Diro and Admasu Tsegaye, 2012).

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Fig. 1. Sucker production from mother corm of different ages (two years average data) (Source: Mulugeta Diro et al., 2001).

Table 4. Number of suckers under different propagation practices.

Propagation Corm type method Whole Halved Quartered Method1 79cde 110abc 64def Method2 113ab 141a 89bcd Method3 94bcd 52ef 40f Means followed by the same letters are not significantly different from each other at 5% probability level Key: Method 1 = replanting mother corms immediately after removal of apical buds; Method 2 = mother corms not uprooted but apical buds removed; Method 3 = mother corms transferred to new holes three months after removal of apical buds. Source: Mulugeta Diro et al., 2002.

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Fig. 2. Whole, halved and quartered corms. Enset corm planting time In most enset growing areas, corm planting for sucker production is exercised during the dry season. It is not known whether farmers practice is the optimum for growth and development of the planting material. Information were generated through planting corm on the 25th of every month for two years (1991-93) and under farmers own management practices such as applying farm yard manure and weeding. The data showed that higher numbers of suckers were produced from March, May and June (Fig. 3). Performance of suckers was generally high from Jan.-March and May-June planted corms. The results showed that Jan.- June can be appropriate time of planting corms for good establishment and subsequent growth of suckers (Endale Tabogie et al., 1994, unpublished).

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Psuedostemht. (cm) Psuedostemdiameter (cm) No. of Suckers Plant height (cm) Leaf length (cm) Leaf width (cm) 70.0 180.0 120 160.0 60.0 100 140.0 50.0 120.0 80 40.0 100.0 60 30.0 80.0 60.0 40 20.0 40.0 20 10.0 20.0

0.0 0.0 0 July April May June July April May June July January March August January March August April May June February October December February October March September November September NovemberDecember January August October February Planting time September NovemberDecember Planting time Planting time

Fig. 3. Effect of planting time (month) on vegetative growth of suckers. Fig. 2. Effect of planting time (month) on different vegetative growth of suckers

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An attempt was also made to compare depth of planting hole for sucker production (Table 5). The whole corm was split longitudinally into two halves and planted in holes of different depth. The experiment was conducted using three years old enset plant. The result showed that in the first year, 20-30 cm depth hole gave better, but not significant number of suckers and pseudostem. Therefore, 20-30 cm depth hole was recommended for planting of halved corms (Mulugeta Diro and Admasu Tsegaye, 2012). Table 5. Effect of depth of planting hole on emergence and growth of suckers. First year Second year Hole Depth No. of Pseudostem No. of Plant Pseudostem Pseudostem (cm) suckers/ height (cm) suckers height height (cm) diameter corm /corm (cm) (cm) 20 50 a 4.4 a 60 a 71.61ab 8.77 a 2.47ab 30 36 ab 4.1 ab 36 ab 85.29 a 14.75a 3.42 a 40 35 ab 3.2 ab 26 ab 70.96ab 11.60a 2.50ab 50 13 b 2.7 ab 8 b 33.73bc 5.06ab 0.82bc 60 7 b 2.1 b 1 b 15.08 c 1.44 b 0.19 c CV(%) 89.6 49.3 104.7 63.11 88.2 77.5 Means followed by the same letter are not significantly different from each other at a probability of 5%. Enset plant usually has vigorous growth and wider canopy, and closer spacing affects the development of enset plants. Plant density trials were started at Holetta and later moved to Wolaita Sodo. Results showed that 3.0 m X 1.5 m was optimum spacing for enset planting (Seifu Gebremariam, 1996). Resent findings at Areka Agricultural Research Centre showed that spacing 2m between plants and 2 m between rows is appropriate for an optimum vegetative growth and yield of enset plants. Moreover, wider spacing not only improves the growth and yield of the plant but also shortens the maturity time. Farmers apply organic waste to enset field year after year. The predominant type of fertilizer used on enset fields is natural fertilizer (farm yard manure). The results showed that an enset plant which obtained a farm yard manure of 5 to 10 kg/plant/year gave better vegetative growth and yield with an early maturity time of about 2 years (Eshetu, 2008, unpublished). It was also shown that application of N and P nutrients increased enset production at Areka. Application of 250 kg Urea and 100 kg DAP ha-1y-1 for two years resulted in better growth and yield of enset (Abay Ayalew and Mikias Yeshitla, 2011). Research achievement and experience in crop protection A number of disease caused by various phytopathogen and pest have been identified on enset. Diseases are caused by nematodes (Mesfin Bogale et al.,

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2004), fungi and viruses (Jones, 2000; Mesfin Tessera et al., 2003), and bacteria (Dagnachew Yirgou and Bradbury, 1968; 1974). Mammals and pests such as porcupine, mole rat, and wild pigs and insects such as mealy bugs (Firdu Azerefegne et al., 2009) are also considered as serious problems (Fikre Handoro et al., 2012). However, the bacterial wilt (EBW), caused by Xanthomonas campestris pv. musacearum, has been the most threatening and economically significant (Dereje Ashagari, 1981; 1985; Eshetu Wondimagegn, 1981; Archido and Mesfin Tezera, 1993; Gizachew Welde- Michael, 2000; Mesfin Tessera et al., 2008; Mohammed Yesuf and Tariku Hunduma, 2012). Enset bacterial wilt disease Enset Bacterial Wilt was first reported on enset (Dagnachew Yirgou and Bradbury, 1968) and later on enset and banana (Dagnachew Yirgou and Bradbury, 1974) in Keffa province of Ethiopia. Then the disease was observed spreading to other enset growing areas (Dereje Ashagari, 1985; Quimio and Mesfin Tessera, 1996). Recently it has been reported that enset bacterial wilt is affecting the crop in all enset growing areas of the country (Mohammed Yesuf and Tariku Hunduma, 2012). Characterization of Xanthomonas campestris pv. musacearum isolates Attempts have been made to determine pathogenic variation of Xanthomonas campestris pv. musacearum using phenotypic, biochemical and rep-PCR studies (Gizachew Welde-Michael, 2000; Kidist Bobosha, 2003; Tsehay Mulaw, 2009). Results suggested that the presence of variations in Xcm among isolates. Earlier, variations among isolates was observed in some preliminary laboratory and field experiments. However, a solid information on genetic diversity of Xcm in Ethiopia is still lacking. Meanwhile, Xcm isolates from East and Central African countries proved to be genetically homogeneous (Aritua et al., 2007; 2008; 2009; Odipio et al., 2009). Recent genome-wide sequencing study suggested the existence of two major sub-lineage of the Xcm pathogen isolated from six East and Central African countries (Wasukira et al., 2012). Detection of Xanthomonas campestris pv. musacearum Different methods have been used for the diagnosis of the bacterium Xanthomonas campestris pv. Musacearum (Xcm). The earlier method used for identifying Xcm is by isolation of bacteria from its infected host and performing fatty acid and metabolic analyses (Tushemereirwe et al., 2004). Later, a polymerase chain reaction (PCR) assay was developed by various

176 Zerihun Yemataw et al. researchers. Lewis Ivey et al. (2010) suggested a specific assay for detecting Xcm based on PCR amplification of the hrpB gene. Adikini et al. (2011) proposed seven PCR primer pairs that are specific for Xcm using sequences from a range of other xanthomonads. However, these two primers lack specificity for Xcm amplification. Recently, DNA primers very specific to amplify Xcm (Adriko et al., 2012) and the genus Xanthomonas (Adriko et al., 2013) were developed. From genome sequence data of multiple Xcm strain, Wasukira et al. (2012) also generated primer sets from strain specific genomic conserved region Xcm. Evaluation of enset cultivars against Xcm A number of studies on artificial inoculation of Xcm against different enset cultivars demonstrated the presence of resistance/tolerance of the pathogen to certain enset cultivars (Archido and Mesfin Tezera, 1993; Gizachew Welde-Michael, 2000; Fikre Handoro and Gizachew Welde-Michael, 2007; Gizachew Welde-Michael et al., 2008a; Mesfin Tessera et al., 2008). Recent literatures also indicated the presence of cultivars with a considerable tolerance/resistance reaction towards Xcm (McKnight, 2013; Befekadu Haile et al., 2014; Tariku Hunduma et al., 2015, Mekuria Wolde et al., 2016) (Table 6). However, completely immune enset cultivars to Xcm have not been found yet. More research is, however, needed considering the vast wealth of enset genetic resources in different enset-growing regions. Table 6. List and description of enset cultivars reported for their lower susceptibility to Xanthomonas campestris pv. musacearum. Name of Level of No. Collection zone Reference landrace resistance* 1 Abatemerza Kembata-Tembaro R/T McKnight, 2013 2 Alagena Wolaita R/T McKnight, 2013 3 Agade Gurage MR Mekuria Wolde et al., 2016 4 Anikefiye Gurage R/T Gizachew Welde-Michael et al., 2008 a McKnight, 2013; Tariku Hunduma et al., 5 Badadiat West & SW Shewa R/T 2015; Mekuria Wolde et al., 2016 6 Bezeriyet Gurage T Gizachew Welde-Michael et al., 2008 a 7 Dere Gurage T Gizachew Welde-Michael et al., 2008 a 8 Dirbo Kembata-Tembaro T McKnight, 2013 9 Gefetano Wolaita R/T McKnight, 2013 10 Gezewet Gurage R Mekuria Wolde et al., 2016 11 Ginbuwa Gurage T McKnight, 2013 12 Godere Wolaita R/T McKnight, 2013 13 Hae’la Kembata-Tembaro HT Mesfin Tessera et al., 2008 14 Hala-a Dawro T McKnight, 2013 15 Halla Wolaita T Gizachew Welde-Michael et al., 2008a 16 He’lla Kembata-Tembaro R/T Mesfin Tessera et al., 2008 17 Hiniba Kembata-Tembaro T Gizachew Welde-Michael et al., 2008a 18 Hiniba West & SW Shewa T Tariku Hunduma et al., 2015

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Name of Level of No. Collection zone Reference landrace resistance* 19 Kechere Gurage MR Mekuria Wolde et al., 2016 Gizachew Welde-Michael et al., 2008a; 20 Lemat Gurage T/S McKnight, 2013; Mekuria Wolde et al., 2016 Gizachew Welde-Michael, 2000; Fikre Handoro and Gizachew Welde-Michael, 21 Mazia Dawro RT 2007; Gizachew Welde-Michael et al., 2008a; Mesfin Tessera et al., 2008; Tariku Hunduma et al., 2015 Gizachew Welde-Michael et al., 2008a; 22 Nechuwe Gurage T/S Million Tadesse et al., 2003; Mekuria Wolde et al., 2016 McKnight, 2013; Befekadu Haile et al., 23 Nobo Sheka R/T 2014 24 Onjamo Kembata-Tembaro T McKnight, 2013; Annual report 25 Sorpie Kembata-Tembaro T Gizachew Welde-Michael et al., 2008a 26 Terye Gurage MR Mekuria Wolde et al., 2016 27 Unjeme Kembata-Tembaro R/T McKnight, 2013 28 Wachiso Kembata-Tembaro R/T McKnight, 2013 29 Warke Dima West & SW Shewa R/T Tariku Hunduma et al., 2015 McKnight, 2013; Gizachew Welde- 30 Yesha Dawro R/T Michael, 2000 31 Yeshirakinke Gurage MR Mekuria Wolde et al., 2016 Disease reaction as reported in the respective literatures: R= resistant, R/T= Resistant or tolerant, MR= moderately resistant; T/S= Tolerant or susceptible, S= Susceptible Epidemiological studies on enset diseases Xcm is reported to survive for up to 3 months in the soil in the absence of a host (Mwebaze et al., 2006) and more than four months on host debris and residues (Gizachew Welde-Michael et al., 2008b; Tripathi et al., 2009). The disease persists on contaminated knives for 3 to 4 days (Dereje Ashagari, 1985). Recently, the pathogen was recovered from fermented enset plant after 105 days of fermentation (Fikre Handoro, 2015). Transmission of enset bacterial wilt from disease to healthy crop plants could occur through all possible means of contact, however, contaminated farm tools are major inoculants (Dereje Ashagari, 1985; Million Tadesse et al., 2003; Karamura et al., 2006; Gizachew Welde-Michael et al., 2008b; Mikias Yeshitla et al., 2010). Spread by animals browsing on infected leaves, use of infected plant materials, repeated transplanting which damage corms and roots, and possibly insects visiting bacterial oozes on enset foliage may also occur (Dagnachew Yirgou and Bradbury, 1974; Eshetu Wondimagegn, 1981; Fikre Handoro et al., 2012). Transmission by insect vector in enset was suggested (Eshetu Wondimagegn, 1981; Fikre Handoro et al., 2012) but there is no clear information on insect and soil borne pathogen mediated transmission of Xcm in enset.

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Natural hosts of Xcm are cultivated enset (Ensete ventricosum) and banana (Musa) (Dagnachew Yirgou and Bradbury, 1968; 1974; Thwaites et al., 2000). Wild Enset (Ensete ventricosum), which is widely distributed in East and Southern Africa, is presumed to be susceptible (Smith et al., 2008). In addition, plant families of Cannaceae (Cana family), Cotaceae (Cotus family), Heliconiaceae (Heliconia family), Marantaceae (Prayer-time family), Strelitziaceae (Birds of Paradise Flower family) and Zingeberaceae (Ginger family) are considered as host plants (Karamura et al., 2008) and could be possible source of inoculum for the pathogen (Dereje Gorfu, 2012). Management of enset bacterial wilt Generally, controlling bacterial diseases of plants is very difficult. The strategy developed for Xcm management includes: A) Cultural practices and sanitary control measures; B) Use of resistant/tolerant enset clones; C) Use of healthy and clean planting materials (suckers/ transplants, corms). Cultural practices and sanitary control measures were efficient to significantly reduce the spread of the pathogen (Million Tadesse et al., 2003). Experiences on the management of Xcm in enset and elsewhere in banana suggest that community mobilization and awareness creation for collective management of the disease is instrumental to effectively control the disease (Million Tadesse et al., 2003; Eshetu Ahmed and Mohammed Yesuf, 2010; Tesfahun Fenta and Karamura, 2012). Zerihun Yemataw et al. (2016c) reported that sensitizing and mobilizing communities in various areas contributed to the significant decline of the incidence of the disease on the crop. Therefore, routine application of phytosanitary measures and agronomic practices minimize spread by individual and community level is currently the most effective way of managing the disease caused by Xcm. Other enset diseases and pests Foliar disease caused by Phyllostical sp., Piricularia sp., Cladosporium sp., and Drechslera sp., have been reported (Quimio and Mesfin Tessera, 1993). Quimio (1992) cited (Quimio and Mesfin Tessera, 1993) also reported Sclerotium wilt and root rot disease caused by Sclerotium rolfsi. Stewart and Dagnachew Yirgou (1967) reported the occurrence of other diseasees caused by Phoma sp., Selenophom sp., Septroria sp., Thielaviopsis sp., Clylindroclasdium quinqueseplatum and Fusarium oxysporium. Earlier, Castellani (1939) indicated that Pseudomonas solanacearum caused a wilt disease on enset. However, the bacterium was not isolated nor tested for its

Ethiop. J. Biol. Sci., 17(Suppl.): 163–189, 2018 179 pathogenicity. Mesfin Bogale et al. (2004) identified nematode species Pratylenchus goodeyi, Aphelenchoides ensete and Meloidogyne spp. that predominantly cause disease in enset. Temesgen Addis et al. (2006) also identified twelve taxa of plant parasitic nematodes associated with enset roots. Different viruses such as uncharacterized banda viruses (Mesfin Tessera et al., 2003) mosaic and chlorotic stunt chlorotic streak also cause different disease of enset (Mesfin Tessera and Quimio, 1993; Quimio and Mesfin Tessera, 1996). Banana aphid, leafhopper, spider mites and mealy bug were frequently observed on both healthy and wilting enset plants and Jassid flies in virus-infected plants (Terefe Belehu and Endale Tabogie, 1989). Temesgen Addis (2005) reported that the enset root mealy bug (Cataenococcus ensete Williams and Matile-Ferrero) has become the most important insect pest of enset (Ensete ventricosum) in Gedio and Sidama zones of southern Ethiopia. These soft bodied insects feed on the corm and roots and the infested enset plants show stunted growth (Brandt et al., 1997). Overall, the management of diseases caused by these pests relies on applying the basic principles of raising health seedlings, proper plot preparation, proper crop management to maintain health plants in the field, coupled with general sanitation practices to minimize the infection. However, resistant enset cultivars and alternative disease control measures such as bio control may be necessary to combat for some of the diseases. Research achievements and experiences on biology and management of enset Root Mealy bug According to Terefe Belehu and Endale Tabogie (1989), banana aphid, leafhopper, spider mites and mealy bug were frequently observed on both healthy and wilting enset plants and Jassid flies in virus-infected plants. Usually these insects were suspected in transmitting bacterial wilt. However, recent survey on enset root mealy bug damage has revealed that it incurred great loss in enset production especially in Gedio and Sidama zones. These soft bodied insects feed on the corm and roots and the infested enset plants show stunted growth (Brandt et al., 1997). The wild animals such as mole rat usually feed on the corm and pseudostem of enset cause considerable damage of enset.

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Research on enset processing Enset processing (which includes scraping, pressing and extraction of bulla) is carried out using traditional tools which are not efficient and are unhygienic (Deribe Kifle, 1996). Lack of labour and time-saving devices is one of the major difficulties in the day-to-day activities of women processors. The heavy work load demands more women's time and energy with less attention given to their child and family feeding responsibilities. The impact of improved processing devices which were developed by different institutions was quite limited (Admasu Tsegaye, 2002). However, several institutes such as Nazareth Agricultural Research Centre, Hawassa University and Rural Technology Promotion Centres have developed and distributed enset decorticators, bulla squeezers and corm graters (Fig. 4). Different NGOs and governmental bodies were involved in the distribution of the devices. To make these improved devices more efficient they should be revised and modified based on feedback collected from end users. When developing rural technologies design developers should make their works more participatory to come up with appropriate technologies.

A B

C D E

Fig. 4. Enset processing devices: Traditional (A) and improved (B) enset decorticators; Traditional (C) and improved (D) Pulverizer; Improved bulla squeezer (E).

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Production packages and technology compilation and dissemination All the currently available improved enset production, bacterial wilt management and other relating technologies with their recommendations have been compiled, documented and published into easily understandable manual, leaflets and posters form and disseminated to the targeted enset producing areas and regions of Ethiopia (Fig. 5) (Zerihun Yemataw et al., 2012b).

Fig. 5. Technology packages (A) Manual; (B) Poster; (C) Leaflets. FUTURE STRATEGIES  Strengthened integrated management of Xanthomonas wilt (EBW) and other diseases.  Strengthened community mobilization and awareness creation about EBW disease through Participatory Development Communication (PDC) approach.  Strengthened exhaustive collection and in vitro conservation

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facilities should be conducted on wild, cultivated and other species.  Strengthened morphological and molecular characterization by encompassing a large number of accessions.  Starting new varieties development through biotechnology based breeding (breeding for host-plant resistance to pathogens and pests in enset).  Sustainable intensification of enset-based cropping systems.  Improvement of the efficiency of processing devices: can minimize energy and time consumption and can also improve sanitary condition during processing for fermentation.  Priority should be given to undertake controlled fermentation studies with selected culture strata and optimize the process into modern food processing technologies. The enset research program needs to follow demand-driven approach to technical change through:  Explicitly considering stakeholders as equal partners in determining the needs and future plans for a dynamic enset research and development;  Building a practical and shared vision for enset R&D;  Building better linkages with private sector organizations;  Better links with and among institutions;  Co-stewardship of research and service outputs with partner institutions; and  Rapid introduction of high-impact technologies through public and private sector partnerships. REFERENCES Abay Ayalew and Mikias Yeshitla (2011). The response of Enset (Ensete ventricosum (Welw) Cheesman) production to rate and frequency of N and P nutrients application at Areka, in Southern Ethiopia. Innov. Syst. Design Eng. 2(7). Adikini, S., Tripathi, L., Beed, F., Tusiime, G., Magembe, E.M. and Kim, D.J. (2011). Development of a specific molecular tool for detecting Xanthomonas campestris pv. musacearum. Plant Pathol. 60: 443–452. Admasu Tsegaye (2002). On Indigenous Production, Genetic Diversity and Crop Ecology of Enset (Ensete ventricosum (Welw.) Cheesman). Doctoral thesis,

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Ethiop. J. Biol. Sci. 17(Suppl.): 191–199, 2018 © The Biological Society of Ethiopia, 2018 ISSN: 1819-8678 RELEVANT RESEARCH QUESTIONS ON THE CROP PHYSIOLOGY OF ENSET

P.C. Struik1

ABSTRACT: Enset is an ideal crop for climate smart, sustainable agriculture, especially in low-input, fragile environments. Its main strengths are: prolonged canopy cover, recycling of nutrients, drought resistance, stable dry matter allocation, large storage capacity of starch, high harvest index, easy vegetative reproduction, and its ability to prevent soil erosion. Enset also has high radiation use efficiency and is tolerant against repetitive removal of leaves and repetitive transplanting. The plant and crop architecture of enset are special and deserve to be investigated in more detail by architectural models, such as functional-structural plant models (FSPMs). Through such FSPMs we can investigate the consequences of (trans) planting and gap filling practices on crop performance. Similarly, FSPMs can be used to assess the effects of repetitive leaf pruning. Moreover, these models should be used for 3D modelling of rainfall interception and water transfer by individual leaves and the entire canopy, enabling the study of water storage in the plant, drought tolerance, water use efficiency and protection against erosion. The influence of leaf tearing and tattering on performance of individual leaves is also relevant. Effects on photosynthesis and transpiration can be either positive or negative at the level of the individual leaves. Upscaling these effects to plant and crop performance is essential. Finally, it is likely that current crop stands are infected by viruses. Quantifying the yield reduction by such infections and the relation between virus titre and crop performance can help to assess the need for virus-free planting material.

Key words/phrases: Functional-structural plant modelling, Leaf pruning, Sustainability, Transplanting, Virus infections.

INTRODUCTION Enset (Ensete ventricosum (Welw.) Cheesman) is a perennial crop plant of great economic and cultural importance in Ethiopia, and is widely used for many different purposes, including food, forage, medicine, building material and fibre (Admasu Tsegaye, 2002) and industrial purposes, such as starch production. While the species widely occurs in tropical Africa, it has only been domesticated in Ethiopia. In this country, enset has become the main staple for many people, especially in the Southern Nations Nationalities and Peoples Regional State (SNNPR), Oromia and Gambela (Admasu Tsegaye, 2002). Enset has a large

1 Centre for Crop Systems Analysis, Department of Plant Sciences, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands. E-mail:[email protected]

192 P.C. Struik genetic diversity (Admasu Tsegaye and Struik, 2000a; Admasu Tsegaye and Struik, 2002). Some of the reasons for this diversity may be the fact that the crop is grown in very different agro-ecosystems and contrasting agro- ecologies. However, also the very diverse purposes of its use have contributed to this diversity. When used for human consumption, enset is a flexible and versatile food source. The plant can be harvested at different growth stages (i.e., over a prolonged period of time and growth) and its products can be stored for long periods (Admasu Tsegaye, 2002). Enset is exposed to some typical cultural practices, such as frequent transplanting to maximize land use efficiency and frequent leaf pruning to provide forage to domestic animals (Admasu Tsegaye and Struik, 2000b; Admasu Tsegaye and Struik, 2002). Such practices have a strong effect on the crop physiology of the species. In this contribution, I will first analyse why enset is a productive and climate robust crop. Subsequently, I will describe the need for functional-structural plant models to understand the crop physiology of enset better. I will also discuss the consequences of leaf tearing and tattering and virus infections. Finally, I will list a few research questions for future (crop physiological) research of enset. Enset is a productive crop Efficient biomass production is based on effectively capturing incoming light over a prolonged period of time and making maximum use of absorbed light though efficient photosynthesis followed by conversion of the fixed carbon through efficient metabolic pathways. Enset does that very well, for several reasons (see, for example, Admasu Tsegaye and Struik, 2001; Admasu Tsegaye and Struik, 2003). Enset can capture huge amounts of light during its life cycle. As a perennial crop with continuous renewal of productive leaves, its typical canopy structure with upright leaves, and its long vegetative phase, it produces a long-lasting, highly productive vegetative apparatus with efficient light capture. The efficiency with which that intercepted light (or radiation) is converted into dry matter (the so-called radiation use efficiency, expressed in g of dry matter per MJ light intercepted) can also be high under conditions without stress. Table 1 presents some values for radiation use efficiency of enset.

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Table 1. Some examples of the high radiation use efficiency (RUE) of enset (Data from Admasu Tsegaye, 2002). Site Clone RUE (g/MJ) Awassa Halla 2.25 Awassa Addo 2.23 Areka Halla 1.43 Areka Nekakia 2.67 The main reasons for that are threefold. First, enset has a very stable dry matter partitioning over the different plant organs, with little investment in plant structures that die at an early stage. The stable dry matter partitioning pattern also guarantees a long period of high fitness for use and therefore high flexibility in harvesting time. Secondly, enset has a large storage capacity of reserves in the corm and pseudostem (i.e., both above- and below-ground). Thirdly, in enset the reserves are stored as starch, which is a relatively “cheap” product for a plant to produce, at least cheaper than oil or proteins. These three reasons result in a high harvest index (expressed in g dry matter harvested per g dry matter of biomass produced), i.e., a large proportion of the dry matter produced is harvestable. The harvestable material is present in an edible form of high quality. The combination of high biomass production, high harvest index, and high-quality storage product makes enset a very productive and reliable staple crop. Table 2 illustrates the high rate of energy production of enset in comparison with other crops with starch as main storage compound. Table 2. Some data to illustrate that enset has a high rate of energy production in comparison with other crops with starch as main storage compound (Data from Admasu Tsegaye, 2002). Crop Energy production rate (kJ m-2 d-1) Enset (transplanting twice) 64.3 Lowest cereal (sorghum) 8.0 Highest cereal (maize) 16.6 Lowest tuber crop (yam) 11.0 Highest tuber crop (sweet potato) 26.5 Enset is a climate smart, sustainable crop for low-input, fragile environments Some of the crop physiological reasons why enset is a productive crop also make it a climate smart, sustainable crop for low-input environments. These include prolonged vegetative growth and long canopy cover, high radiation use efficiency, stable dry matter allocation pattern (and therefore long period of fitness for use), high harvest index, and large storage capacity of starch (both below- and above-ground), as discussed before. However, enset has a number of other attractive characteristics that make it climate smart and sustainable, including its deep rooting, cold tolerance, drought

194 P.C. Struik resistance and its high nutrient use efficiency. Deep rooting allows foraging for water and nutrients over a wide soil volume. Enset’s cold tolerance is clearly demonstrated by the wide agro-ecological distribution of the plant and its cultivation at higher altitudes (Table 3). Its drought tolerance is associated with the capture of large amounts of water with its leaves and its capacity to store this water in the pseudostem. The high nutrient use efficiency is associated with nutrient recycling associated with the thick layer of mulch in enset stands consisting of leaf litter, but also with the fact that per unit of nutrient taken up a large quantity of starch can be accumulated in the vegetative storage organs. The combination of drought tolerance and nutrient recycling in association with high water and nutrient use efficiencies makes enset also a sustainable crop for low-input, fragile environments. Moreover, the crop can easily be established making use of its easy vegetative reproduction through numerous and vigorous suckers. Enset also demonstrates many different ecosystem services, such as soil protection against erosion (based on mulching with leaf litter and continuous and prolonged vegetation cover), providing shading and shelter, and harbouring biodiversity. In addition to food, it produces many other valuable components. Enset is also tolerant to (repetitive) transplanting, allowing more efficient use of land, and leaf pruning and allowing frequent harvesting of leaves for forage. Important crop physiological issues Enset has some typical characteristics that require in-depth investigation to assess their physiological and agronomic consequences. First of all, an enset stand has a very characteristic and unique plant and canopy structure, with its stiff and upright leaves that create special vertical light profiles and special pathways of water movement. Moreover, the leaf appearance of enset is slow and leaf longevity potentially long. Due to prevailing strong winds in many enset growing areas, leaf tearing and tattering are frequent and these affect transpiration (and therefore leaf temperature) and leaf photosynthesis. For plants other than enset it has been demonstrated that leaf tattering can help in increasing the transpiration and therefore in cooling the photosynthesis apparatus. Therefore, in conditions in which heat stress effects on photosynthesis are relevant, leaf tattering might be a blessing in disguise. Strong leaf tattering, however, obviously might reduce the photosynthesis efficiency, as it causes physical leaf damage and reduces the longevity of the leaves, but the influence of the extent of tattering on photosynthesis and transpiration requires further research. Upscaling these

Ethiop. J. Biol. Sci., 17(Suppl.): 191–199, 2018 195 influences to the canopy level is essential to quantify consequences for plant and crop performance. Enset is also very diverse in pigmentation. Leaf blades might range from light green to dark green and even dark red. The impact of leaf colour on radiation use efficiency and protection of the plant against too much radiation is an interesting issue to further investigate, preferably at different altitudes. According to Admasu Tsegaye (2002) and other publications (Admasu Tsegaye and Struik, 2000b; Admasu Tsegaye and Struik, 2003), flowering should be delayed to prolong the starch accumulation in the pseudostem and corm. Flowering can be delayed by repetitive transplanting and perhaps by other traditional cultural practices as well. The mechanisms behind the impact of transplanting on the vegetative and reproductive development of enset require further physiological study. It is also important to assess nutrient cycling (especially of N, P, and K) and nutrient accumulation, the more so since often households concentrate the nutrients available in their farming system in the enset stands. Equally important is to quantify water storage in enset plant, water flows in enset stands, and water movement in soil underneath these stands. With these water flows, also the nutrient flows are influenced. We are especially intrigued by the possibilities to investigate the impact of canopy structure making use of functional structural plant models, as will be discussed in the next section. Functional-structural aspects of enset Enset growing regions but also individual households differ significantly in the way crop stands of enset are established. Often enset is frequently transplanted, sometimes with clear separation of enset plants of different ages in the home garden. Transplanting is often preceded by leaf pruning and is associated with changes in plant density. The impact of combined leaf pruning and (different frequencies of) transplanting is illustrated in Fig. 1. Note the positive effect of more frequent transplanting on the yield because of delaying flowering (and thereby delayed plant senescence) and the interaction between leaf pruning and transplanting frequency.

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Early senescence

Fig. 1. Effects of transplanting and leaf pruning on fresh kocho yield per plant after processing (assessed 260 days after first transplanting; upper panel) and dry kocho yield per ha per year (assessed 130 days after first transplanting; lower panel) (Data from Admasu Tsegaye, 2002). There are also mature crop stands where harvested enset plants are replaced by smaller plants and the logics behind the various gap filling strategies in mature stands also need to be unravelled. Even without transplanting, leaf

Ethiop. J. Biol. Sci., 17(Suppl.): 191–199, 2018 197 pruning of different levels of intensity is applied. The traditional practices of transplanting and leaf pruning are not only designed to influence crop physiology, but are triggered by the need to make maximum use of scarce land or by the organization of the home garden (transplanting) or are influenced by the number of animals per household and thus the household’s forage needs. Therefore, these common practices of transplanting and leaf pruning can vary a lot among agro-ecologies, and may even be counterintuitively associated with yield potentials as illustrated in Table 3. Table 3 indicates that the logic behind transplanting and leaf pruning are very much based on resource management and not on crop physiology. Table 3. The frequency of transplanting and the level of leaf pruning for several enset growing regions differing in elevation (After Admasu Tsegaye, 2002). Region Elevation (m Frequency of Level of asl) transplanting leaf pruning Sidama 2600-2650 Once Mild Wolaita 1750-1820 2-3 times Very severe Hadiya 2220-2400 4 times Moderate Using general eco-physiological models, the crop physiology and crop ecology of enset have been investigated but many relevant research questions have remained untouched. Because of its upright and rigid leaves, the plant and crop architecture of enset are special and deserve to be investigated in more detail by architectural models, such as functional- structural plant models (FSPMs). Apart from generating a very attractive 3D visualisation of plant growth, these models are particularly suited to analyse problems in which spatial structure of the plant or its canopy is an essential factor to explain performance, or – in other words – to link form and function. Through such FSPMs we can investigate the consequences of (trans)planting strategies, gap filling practices in mature stands, and plant arrangements of stands of different ages on the performance of the crop, thus evaluating the contrasting approaches in crop management by different tribes in the enset growing regions. Similarly, FSPMs (in combination with ecophysiological approaches of dry matter production and allocation) can be used to assess the effects of repetitive leaf pruning, and the interactions between leaf pruning, (changes in) plant arrangement and/or (repetitive) transplanting. Moreover, these models should be used for 3D modelling of rainfall interception and water transfer by the individual leaves and the entire canopy, which can help to study water storage in the plant, drought tolerance, water use efficiency, nutrient recycling, nutrient use efficiency

198 P.C. Struik and protection against erosion by the crop. Virus infections might reduce yield Finally, because of the vegetative propagation it is likely that current crop stands are infected by viruses. Although it has not been investigated, the low value of the radiation use efficiency of the clone Halla in Areka in Table 1 might be associated with virus infection. Quantifying the yield reduction by such infections and the relation between virus titre and performance can help to assess the need for virus-free planting material. Future research questions Based on the previous sections, I would like to list the following major research questions for further increase in our knowledge on the crop physiology of enset: 1. Are enset leaves designed to be torn and how much does leaf damage matter? 2. What are the exact mechanisms behind the different transplanting benefits? 3. How much leaf removal can the plant or crop tolerate at different agro-ecologies? 4. Is it possible to design improved planting systems based on functional-structural plant models? 5. How can we capitalize on the climate-robustness of enset? 6. How important are viruses to account for variation in radiation use efficiency? 7. Is there a relationship between virus titre and plant vigour or radiation use efficiency? ACKNOWLEDGEMENTS I am very grateful to Professor Admasu Tsegaye who introduced me into the wonderful world of enset and who shared with me his deep knowledge on the agronomy, ecophysiology and ethnobotany of the crop and exposed me to its various uses and processing procedures. REFERENCES Admasu Tsegaye (2002). On Indigenous Production, Genetic Diversity and Crop Ecology of Enset (Ensete ventricosum (Welw.) Cheesman). Doctorate Thesis, Wageningen University, Wageningen.

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Admasu Tsegaye and Struik, P.C. (2000a). Research supporting the genetic diversity of enset in southern Ethiopia. In: Encouraging Diversity. The Conservation and Development of Plant Genetic Resources, pp. 245–249 (Almekinders, C. and de Boef. W., eds.). Intermediate Technology Publications, London. Admasu Tsegaye and Struik, P.C. (2000b). Influence of repetitive transplanting and leaf pruning on dry matter production of enset (Ensete ventricosum Welw. (Cheesman)). Field Crops Res. 68: 61–74. Admasu Tsegaye and Struik, P.C. (2001). Enset (Enset ventricosum (Welw.) Cheesman) kocho yield under different crop establishment methods as compared to other carbohydrate-rich food crops. Neth. J. Agric. Sci. 49: 81–94. Admasu Tsegaye and Struik, P.C. (2002). Analysis of enset (Ensete ventricosum) indigenous production methods and farm-based biodiversity in major enset- growing regions of southern Ethiopia. Exp. Agric. 38(3): 291–315. Admasu Tsegaye and Struik, P.C. (2003). Growth, radiation use efficiency and yield potential of enset (Ensete ventricosum) at different sites in southern Ethiopia. Ann. Appl. Biol. 142: 71–81.

Ethiop. J. Biol. Sci. 17(Suppl.): 201–209, 2018 © The Biological Society of Ethiopia, 2018 ISSN: 1819-8678 A PERSPECTIVE TO ENHANCE INNOVATIVE RESEARCH WITH EMPHASIS ON VARIETAL DIVERSITY AND SUSTAINABLE UTILIZATION OF ENSET (ENSETE VENTRICOSUM)

Paul Wilkin1,*, Aaron Davis1, Sebsebe Demissew2, Tom Etherington1, Mark Goodwin3, Pat Heslop- Harrison3, Trude Schwarzacher3 and Kathy Willis1

ABSTRACT: The current status of enset in cultivation in Ethiopia and its more widely distributed wild populations is reviewed. Biodiversity research gaps are identified, and the potential benefits of the plant and benefits of undertaking that research are discussed, in particular on food and resource security and livelihoods in Ethiopia. Knowledge of the resilience of enset will provide the evidence base underpinning a decision whether to expand its use in Africa.

Key words/phrases: Diversity, Enset, Food security, Livelihoods, Resilience.

INTRODUCTION Enset (ensete, Ethiopian or Abyssinian banana; Ensete ventricosum (Welw.) Cheesman, Musaceae) is a perennial herbaceous plant that can achieve 12 m in height when flowering. It is similar in vegetative form to the related banana and plantain (Musa x paradisiaca L.), possessing a false stem and large, paddle-shaped leaves. It is distributed across central, eastern and southern Africa (Lye and Edwards, 1997; e-Monocot, 2016). Despite this widespread distribution in Africa it has only been domesticated in Ethiopia, with hundreds of landraces and farmers’ varieties found in diverse climatic and agroecological systems providing multiple ecosystem services (Ehret, 1979; Brandt, 1996; Yemane Tsehaye and Fassil Kebebew, 2006). Unlike banana and plantain that are farmed for their fruit, its swollen stem base and corm provide a long term, year-round and potentially low off-farm input dietary starch source for 20 million people in southern and southwestern Ethiopia. Food is harvested in multiple forms from different parts of the corm and leaf sheaths (Dessalegn Rahmato, 1996). Enset has a number of important attributes as a crop. Perhaps the most significant is its potential to be a climate-smart crop for the future based upon its apparent ability to withstand long periods of drought (e.g. Quinlan

1 Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB 2 National Herbarium of Ethiopia, Department of Plant Biology and Biodiversity Management, College of Natural and Computational Sciences, Addis Ababa University, P.O. Box 3434, Addis Ababa, Ethiopia 3 Department of Genetics, University of Leicester, LE1 7RH UK *Author to whom all correspondence should be addressed

202 Paul Wilkin et al. et al., 2015). The plant can be harvested at any time during the year and at any stage over several years. Enset-derived starchy foods can also be stored for long periods (Mulugeta Diro and Endale Tabogie, 1994; Genet Birmeta, 2004). The crop has been reported to produce the highest yield per unit land area in Ethiopia (Tadesse Kippie, 2001). The carrying capacity of land planted to enset is around 0.2 hectares for a household of seven people, as opposed to 1.5 hectares of land with annual grain; yield from enset therefore has the ability to support a larger population per unit area than regions that grow cereals (Teshome Yirgu, 2016). Enset also supplies fibres, traditional medicines, animal fodder and a food source for bees (Brandt et al., 1997). As a perennial crop not requiring frequent soil cultivation and periods of fallowing, enset stabilises soils and microclimates (Tsedeke Abate et al., 1996) and is culturally significant (Shigeta, 1997; Tadesse Kippie, 2001). As a result of these attributes, enset farming provides a long-term, sustainable food supply, with minimum off-farm input. Despite the current importance of enset and its potential to play a more substantial role in resource provision at a broader scale, relatively less is known about its biology compared to other crops in Ethiopia. This includes aspects of its reproductive morphology, pollination and dispersal and the genetic diversity of both wild and cultivated forms. There is also limited understanding of its susceptibility to disease, associated mycorrhizal assemblages and resilience to pests and pathogens. There has been little international research on enset involving scientists from outside Ethiopia. Thus collaborative biodiversity science is needed to fill critical knowledge gaps and thus enable the exploitation of enset diversity as a resilient climate- smart crop of the future. A similar programme has generated significant recent improvements in Cassava performance (e.g. Prochnick et al., 2012; Ceballos et al., 2012). SPECIFIC RESEARCH NEEDS Research in the following areas is suggested to provide the information resources needed to enhance exploitation of enset: a. Comprehensive field surveying in order to provide a complete and unified picture of enset’s underground and above ground vegetative morphological traits (agronomic and otherwise) and their variation across Ethiopia, covering both wild populations and the hundreds of cultivated forms (farmers’ varieties). These data should be linked to that generated from dedicated climate stations co-located with the field surveys, including rainfall, temperature, humidity, soil water moisture/potential. They also

Ethiop. J. Biol. Sci., 17(Suppl.): 201–209, 2018 203 need to be coupled to farmer and farm surveys capturing farmers’ knowledge and season-by-season feedback on enset cultivation, market price, crop use, traditional cultural practices, and biodiversity and ecosystem service provision. All such data would need dedicated ground-truthing. It would then be possible to fully determine and assess the environmental suitability of enset variation across the entire Ethiopian enset-growing landscape via bioclimatic modelling using proven, state-of-the-art species distribution model (SDM) methodologies (e.g. Hannemann et al., 2015) for producing bioclimatic envelopes and accurate mapping of trait distribution in unmanaged and cultivated environments in Ethiopia using advanced GIS tools. Resilience traits and their locations would be determined, and varieties identified that grow and yield well in challenging environmental conditions. This research would allow comparison with other climate smart crops that are candidates to play a part in improving lives and livelihoods in Africa. b. Determination of inflorescence form and function. Remarkably little is known about the reproductive morphology of enset beyond basic botanical description (e.g. Lye and Edwards, 1997). Cultivated enset is propagated vegetatively and traditionally harvested before or at the point of inflorescence initiation when the corm is at its largest. Hence inflorescence- bearing plants are rarely encountered (Genet Birmeta et al., 2004) and gene flow does not occur between farms or from wild to cultivated plants to recombine diversity. Wild enset produces inflorescences on what is thought to be an irregular multi-year cycle, but there is no data on factors stimulating the transition to flowering. Basic data is needed on inflorescence initiation and form, floral morphology, pollination, fruit morphology and development and seed biology. Knowledge of these traits is necessary to underpin successful conventional breeding of this crop and conservation under in and ex situ approaches (germplasm collections and seed banking). Low levels of genetic diversity resulting from cultivation of a small number of clones potentially reduce resilience to pathogens, at least on a local scale. Hence, there is a need to propagate and improve enset through sexual reproduction. This suggests that investigation of flowering phenology and development, morphology, pollination mechanisms and seed germination biology are required. This should be undertaken via field studies of wild or feral plants, with inflorescence condition being recorded over time including via photography and floral visitor capture (following the methodological principles of Faegri and van der Pijl, 1979; Dafni, 1992) and make dried and ethanol-preserved specimens for later study of morphology and

204 Paul Wilkin et al. development. The form and colour of the inflorescence suggest moth pollination, indicating the need to employ an infrared video camera in night mode to record nocturnal visitors. c. Quantification of the genetic diversity of cultivated and wild enset in Ethiopia. There have been limited studies of genetic diversity in cultivated enset (e.g. Zerihun Yemataw et al., 2016a) but no comprehensive research at landscape scale. Genomic techniques that have been applied extensively to other crops including the closely related banana are only starting to be deployed for enset (Harrison et al., 2014). A comprehensive survey of genetic diversity at population and landscape scale across enset growing regions of Ethiopia is required, as advocated in e.g. Poland and Rife (2012). Such a survey should include whole genome and targeted sequencing and comparison with the latest banana genome assembly (Droc et al., 2013). Analysis of earth observation data from satellites, typically 30 x 30 m resolution or better, would need to be tested and trained to see if the crop can be measured in the field, discriminated from bananas, and growth stage or potential yield estimated. It would also require genotyping by sequencing strategies, including levels of heterozygosity and population genetic structures and identification by comparison with Musa and other reference genomes of genes relating to developmental processes of flowering, fruiting, starch biosynthesis and storage, and disease resistance. Ultimately, this research would lead to molecular markers and selection criteria for identifying pre-breeding lines. d. Surveying ploidy across the distribution of enset to test the hypotheses that only diploids exist in the wild and cultivated populations (Genet Birmeta et al., 2004). Mapping ploidy would enable its potential link to resilience (e.g. Henry and Nevo, 2014) to be evaluated. e. Determining the resilience of cultivated enset to pests and pathogens. There has been some research on bacterial wilt caused Xanthomonas campestris pv. musacearum) (e.g. Tariku Hunduma et al., 2015; Zerihun Yemataw et al., 2016b). The role of mole rats as agricultural pests of enset is also recorded (Earecho, 2015). However, the importance of pathogenic fungi and viruses and other key pests of tuberous crops such as nematodes is significantly under-recorded (see e.g. Blomme et al., 2013). This knowledge gap needs to be addressed both via field surveys and farmer interviews and inventory and investigation at genetic level. These data will determine patterns and intensity of occurrence and test the effect of existing management practices (which need to be documented) so that potential

Ethiop. J. Biol. Sci., 17(Suppl.): 201–209, 2018 205 impacts from pests and pathogens can be included within enset distribution suitability models. Stress resistance genes should be sought and characterized from unimpacted populations and varieties within outbreak areas, and disease resistant forms conserved in germplasm collections. f. Relationships with mycorrhizal fungi and other soil organisms. The microbiome has been shown to influence plant performance and is important for growth and development, nutrient acquisition, tolerance to biotic and abiotic stresses, for protection against pathogens and to sustain soil quality. Knowing how the phytobiome networks is an essential tool for acrosystem breeding, and should be considered as an additional factor in plant breeding programmes (e.g. Berg et al., 2014; Bulgarelli et al., 2013). Therefore, investigations into the phytobiome using an environmental sequencing approach are required to assess its relationship with resilience and its potential importance to enset breeding. POTENTIAL BENEFITS AND BENEFICIARIES The drivers underlying research on enset are the human and environmental challenges facing Ethiopia and Africa as a whole as the 21st century unfolds. Chief among them is provision of sufficient food to the continent’s population as it doubles in size by 2050 (based on the latest UN Department of Economic and Social Affairs figures) against a backdrop of a changing climate with a projected increase in frequency of droughts. Ethiopia’s population is predicted to rise from an estimated 100 M in 2016 to 240 M in 2100. Multiple solutions will be needed, including diverse, resilient, productive crops like enset that can help to increase local production and reduce supply chain lengths and need for imports. The same arguments also apply to the other provisioning, regulating, supporting and cultural services currently or potentially supplied by enset, including energy, animal fodder and medicine production for a rapidly growing population. Not only will Africa’s population increase faster than any other part of the globe, it will also undergo unprecedented urbanization. Fifty percent of the population of Africa will be urbanized by 2050. The population of Addis Ababa has been predicted to increase from an estimated 3.4 M in 2016 to 35.8 M in 2100. Enset starch products can be stored and improve their flavour through storage, making them particularly suitable for urban food supply in comparison with other tuber crops in which storage and transport are major disincentives to use. Recently, evidence has begun to emerge of new value chain networks for enset, with urban Ethiopians acquiring a renewed interest in enset products as elements of their national cuisine

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(Geda, 2009). All of the challenges around ecosystem service provision in Africa and Ethiopia have to be met under the impact of climate change. It has been widely reported, based on current modelling-derived evidence from the IPCC that Africa will be among the most impacted areas of the planet. The research ideas outlined here will place policymakers on the path to knowing where, when and how enset could help to provide for Ethiopia and Africa’s future. Enset has the potential to help many other African nations, particularly those in eastern, southern and central Africa where it is native and climatic regimes are similar to that of Ethiopia, via provision of food, bioenergy and other ecosystem services. CONCLUSION The research suggested has the potential to improve the understanding of resource security and supply of enset. The genotypic and phenotypic resources developed would form the basis of subsequent research that would be focused on breeding novel, resilient, high yielding varieties geared to local conditions in Ethiopia and the evidence to support a decision on whether to expand its cultivation in Africa. Without research that leads to understanding of its diversity and ecology, this diverse, Ethiopia-specific, culturally embedded orphan crop with ingenious/original cultivation practices is likely to continue to decline relative to minimally diverse introduced crops that are potentially less resilient and provide fewer ecosystem services. A modern science-based inventiveness, mainly guided by adaptation to climate change and response to population pressures and food security drives may be the minimum required to revolutionize and transform enset cultivation in Ethiopia. Promotion of resilience within enset will enhance its role in all future resource provision. Making available enset’s full variation to farmers will reduce inputs (including labour, agrochemicals and water) and increase outputs (including reduction in both field and post-harvest losses). This will in turn impact livelihoods and economic development at local, regional and national scale. ACKNOWLEDGEMENTS We would like to thank the organizing committee of the International Workshop on Enset (Ensete ventricosum) for Sustainable Development, Oct. 17-18 2016, Addis Ababa University especially. Prof. Admasu Tsegaye. We also thank colleagues that participated in the multidisciplinary workshop

Ethiop. J. Biol. Sci., 17(Suppl.): 201–209, 2018 207 for their thoughtful and stimulating presentations on the crop and how to maximize its exploitation and impact. REFERENCES Berg, G., Grube, M., Schloter, M. and Smalla, K. (2014). Unraveling the plant microbiome: Looking back and future perspectives. Front. Microbiol. 4,5: 148. doi: 10.3389/fmicb.2014.00148 Blomme, G., Pillay, M., Viljoen, A., Jones, D., De Langhe, E., Price, N., Gold, C., Geering, A., Ploetz, R., Karamura, D., Tinzaara, W., Teycheney, P.-Y., Karamura, E., Lepoint, P. and Buddenhagen, I. (2013). A historical overview of the appearance and spread of Musa pests and diseases on the African continent: Highlighting the importance of clean planting materials and quarantine measures. In Proc. Int. ISHS-Pro. Musa Symp. on Bananas and Plantains: Towards Sustainable Global Production and Improved Uses, pp. 89–102 (Van den Bergh, I. et al., eds.). Acta Hort. 986, ISHS. Brandt, S.A. (1996). A model for the origins and evolution of enset food production. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 172–187 (Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam, eds.). Proceedings from the International Workshop on Enset. Institute of Agricultural Research, Addis Ababa. Brandt, S.A., Spring, A., Hiebsch, C., McCabe, J., Endale Tabogie, Mulugeta Diro, Gizachew Wolde-Michael, Gebre Yntiso, Shigeta, M. and Tesfaye, S. (1997). The "Tree against Hunger": Enset-Based Agricultural Systems in Ethiopia. American Association for the Advancement of Science, Washington, DC. Bulgarelli, D., Schlaeppi, K., Spaepen, S., Ver Loren van Themaat, E. and Schulze-Lefert, P. (2013). Structure and functions of the bacterial microbiota of plants. Ann. Rev. Plant Biol. 64: 807–838. Ceballos, H., Hershey, C. and Becerra-López-Lavalle, L.A. (2012). New approaches to cassava breeding. In: Plant Breeding Reviews, Volume 36 (Janick, J., ed.). John Wiley & Sons, Inc., Hoboken, NJ. Dafni, A. (1992). Pollination Ecology. Oxford University Press, New York. Dessalegn Rahmato (1996). Resilience and vulnerability: Enset agriculture in Southern Ethiopia. In: Enset-Based Sustainable Agriculture in Ethiopia, pp. 83–106 (Tsedeke Abate, Hiebsch, C., Brandt, S.A., and Seifu Gebremariam, eds.). Proceedings from the International Workshop on Enset. Institute of Agricultural Research, Addis Ababa. Droc, G., Lariviere, D., Guignon, V., Yahiaoui, N., This, D., Garsmeur, O., Dereeper, A., Hamelin, C., Argout, X., Dufayard, J.-F., Lengelle, J., Baurens, F.-C., Cenci, A., Pitollat, B., D’Hont, A., Ruiz, M., Rouard, M. and Bocs, S. (2013). The Banana Genome Hub. Database doi:10.1093/database/bat035 Earecho, M.K. (2015). Demonstration of effective management option for mole rat of enset in Kafa Zone. J. Poverty Invest. Develop. 17. Ehret, C. (1979). On the antiquity of agriculture in Ethiopia. J. Afr. Hist. 20: 161–177. e-Monocot (2016). www.emonocot.org, accessed 12 Sep 2016. Faegri, K. and van der Pijl, L. (1979). The Principles of Pollination Ecology. Third edition. Pergamon Press, Rev., New York. Geda, T.W. (2009) Globalization and Neo-liberalization: Challenges and Opportunities to Enset Crop-based Agricultural Communities and their Farming System in

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Ethiopia. Doctoral Thesis, University of Alberta. Genet Birmeta (2004). Genetic Variability and Biotechnological Studies for the Conservation and Improvement of Ensete ventricosum. Doctoral Thesis, Swedish University of Agricultural Sciences, Alnarp. Genet Birmeta, Nybom, H. and Endashaw Bekele (2004). Distinction between wild and cultivated enset (Ensete ventricosum) gene pools in Ethiopia using RAPD markers. Hereditas 140: 139–148. Hannemann, H., Willis, K.J. and Macias-Fauria, M. (2015). The devil is in the detail: Unstable response functions in species distribution models challenge bulk ensemble modelling. Global Ecol. Biogeogr. 25: 26–35. Harrison, J., Moore K.A., Paszkiewicz, K., Jones, T., Grant, M.R., Daniel Ambachew, Sadik Muzemil and Studholme, D.J. (2014). A draft genome sequence for Ensete ventricosum, the drought-tolerant “tree against hunger”. Agron. 17: 13–33. Henry, R.J. and Nevo, E. (2014). Exploring natural selection to guide breeding for agriculture. Plant Biotechnol. J. 12: 655–662. Lye, K.A. and Edwards, S. (1997). The Family Musacae. In: Flora of Ethiopia and Eritrea, pp. 317–321 (Edwards, S., Sebsebe Demissew and Inga, H., eds.). Vol. 6. Addis Ababa. Mulugeta Diro and Endale Tabogie (1994). In: Proceedings of the Second National Horticultural Workshop of Ethiopia, pp. 120–131 (Herath, E. and Dessalegn, L., eds.). 1-3 Dec. 1992, IAR, Addis Ababa. Poland, J.A. and Rife, T.W. (2012). Sequencing is revolutionizing plant genetics and applied plant breeding. Plant Genome 5: 92–102. Prochnick, S., Reddy Marri, P., Desany, B., Rabinowicz, P.D., Kodira, C., Mohiuddin, M., Rodriguez, F., Fauquet, C., Tohme, J., Harkins, T., Rokhsar, D.S. and Rounsley, S. (2012). The cassava genome: Current progress, future directions. Trop. Plant Biol. 5(1): 88–94. Quinlan, R.J., Quinlan, M.B., Dira, S., Caudell, M., Sooge, A. and Assoma, A.A. (2015). Vulnerability and resilience of Sidama enset and maize farms in southwestern Ethiopia. J. Ethnobiol. 35: 314–336. Shigeta, M. (1997). Essence of indigenous sustainability and diversity: Enset system. In: Proceedings of the XIIIth International Conference on Ethiopian Studies, Ethiopia in Broader Perspective, Vol. 3, pp. 883–892 (Fukui, K., Kurimoto, E. and Shigeta, M., eds.). 12-17 December, Kyoto. Tadesse Kippie (2001). Five Thousand Years of Sustainability? A Case Study on Gedeo Land Use (southern Ethiopia). Doctoral Thesis, Wageningen University, Tree mail Publishers, Heelsum. Tariku Hunduma, Kassahun Sadessa, Endale Hilu and Mengistu Oli (2015). Evaluation of enset clones resistance against enset bacterial wilt disease (Xanthomonas campestris pv. musacearum). J Vet. Sci. Technol 6: 232. doi:10.4172/2157- 7579.1000232 Teshome Yirgu (2016). Land use dynamics and challenges of Enset (Ensete ventricosum) agriculture in the upper reaches of Baso-Deme watershed, Gamo Highland, SW Ethiopia. G.J.I.S.S. 5(3): 20–28. Tsedeke Abate, Hiebsch, C., Brandt, S.A. and Seifu Gebremariam (eds.) (1996). Enset- Based Sustainable Agriculture in Ethiopia. Proceedings from the International Workshop on Enset. Institute of Agricultural Research, Addis Ababa. Yemane Tsehaye and Fassil Kebebew (2006). Diversity and cultural use of Enset (Enset

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ventricosum (Welw.) Cheesman) in Bonga in situ conservation site, Ethiopia. Ethnobot. Res. Appl. 4: 147–157 Zerihun Yemataw, Kassahun Tesfaye, Tesfaye Taddese, Tesfaye Dejene, Sadik Muzemil, Zeritu Shashego and Daniel Ambachew (2016a). Genetic variation for corm yield and other traits in Ethiopian enset (Ensete ventricosum (Welw.) Cheesman). J. Plant Breeding Crop Sci. 8(9): 150–156. DOI: 10.5897/JPBCS2015.0555 Zerihun Yemataw, Awole Zeberga, Sadik Muzemil, Fikre Handoro and Mikias Yeshitla (2016b). Community mobilization and awareness creation for the management of Enset Xanthomonas Wilt (EXW): The case of Gerino Enset Tekil Kebele administration, Gurage Zone, Southern Ethiopia. Am. J. Plant Sci. 7: 1765–1781.

Ethiop. J. Biol. Sci. 17(Suppl.): 211–213, 2018 © The Biological Society of Ethiopia, 2018 ISSN: 1819-8678 ADDIS ABABA DECLARATION ON ENSET

The “International Workshop on Enset (Ensete ventricosum) for Sustainable Development: Current research trends, gaps and future direction for a coordinated multidisciplinary approach in Ethiopia” has taken place between October 17 and 18, 2016.

INTRODUCTION Over 20 scientific papers in thematic areas in both Natural and Social Sciences including: Agronomy, Agroforestry, Ethnobotany, Genetics, Modelling, Industrial application, Food security, Nutrition and Dietary aspects, and Socio-economics, were presented in the International Workshop on Enset (Ensete ventricosum) for Sustainable Development on October 17 and 18, 2016. The current research trends, knowledge gaps and future directions were assessed in each of these papers. The discussions following the presentations revealed the uniqueness of the crop, the status of its biodiversity in Ethiopia and its potential to become an important food crop and industrial crop in Ethiopia and beyond. Furthermore, the importance of enset for food security, especially for the rural poor, and the importance for the livelihood and culture of many peoples of Ethiopia was highly stressed. PREAMBLE  Recognizing that Enset (Ensete ventricosum) is a widely occurring species in tropical Africa but has only been domesticated in Ethiopia where it has been in use for at least 10,000 years,  Underlining that enset is an indigenous multipurpose crop species used for food, feed, medicine, fiber, and for industrial purposes,  Appreciating that enset is a main staple for about 20 million people (20% of the Ethiopian population), mainly in the Southern Nations Nationalities and Peoples Regional State, but also in Oromia and Gambela Regions,  Highlighting that the domestication of a wide genetic diversity has been created and maintained, enhanced by the diverse use and the diverse agronomy in the different agro-ecosystems and agro-ecologies,  Highlighting that conservation and sustainable use of biological diversity as well as the environmental services provided by the ecosystems have a strategic value for sustainable development,

212 Declaration on enset

 Appreciating that enset is highly flexible in its use, as it can be harvested over a prolonged period of growth and its products can be conserved for a very long time as well, it can therefore serve as a food bank for times of scarcity,  Considering that enset is a climate-robust and sustainable crop that is very suitable for fragile, low-input environments given its many, diverse ecosystem services,  Recognizing fundamental roles of women in farming systems and the perpetuation of associated traditional knowledge, integrated management of food production and conservation of biodiversity,  Stressing that research on enset has not been given enough attention compared to cereal crops both at the national and regional levels,  Recognizing that local communities play an important role in the economic, social and environmental development, and the importance of sustainable traditional farming practices related to biodiversity and the use of their resources,  Appreciating that the Southern Peoples, Nations and Nationalities Regional State recognizes enset as the most important crop in the region in its agricultural policy and is prepared to take appropriate constitutional steps. The participants HAVE AGREED ON THE FOLLOWING ACTIONS:  To identify National Universities, Institutions and international partners that would participate in research, extension, community service, etc. relating to all aspects of the enset crop.  To organize a consultative meeting of relevant (national and international) stakeholders to establish a Centre of Excellence for Research and Extension for enset in partnership with the Federal Government with clear mandates and responsibilities, and adequate funding.  To actively seek the interest of international donors to support the development of such a Centre of Excellence.  To develop a Conceptual Model for Enset research and extension.  To identify all relevant stakeholders with rural communities.  To guide the shift from the current practice of isolated research on a

Ethiop. J. Biol. Sci., 17(Suppl.): 211–213, 2018 213

particular field to a coordinated and concerted multidisciplinary approach both at national and international levels.  To align with international centres on root and tuber crops and banana such as the International Institute of Tropical Agriculture and the International Potato Centre.  To guide enset research in order to create focus on providing solutions to the problem of the rural communities (such as enset bacterial wilt) and the use of enset and enset ecosystems on a sustainable basis. The participants expressed their full commitment and support in all means and ways for the success of the conservation and utilization of enset for the benefit of the communities and the establishment of the Centre of Excellence which will work towards its sustainability.

Addis Ababa University, 18 Oct. 2016

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ETHIOPIAN JOURNAL OF BIOLOGICAL SCIENCES VOLUME 17, SUPPLEMENTARY (2018) CONTENTS

Preface ------iii–iv

Review of the history, taxonomy and nomenclature of Ensete and the objectives and expectations of the international workshop on Ensete ventricosum (Welw.) Cheesman ------1–23 Sebsebe Demissew and Ib Friis

Trends and gaps in enset (Ensete ventricosum (Welw.) Cheesman research ------25–36 Masresha Fetene and Getahun Yemata

The centre of origin and domestication of Ensete ventricosum (Welw.) Cheesman and its phylogenetic relationship to some Musa species ------37–49 Endashaw Bekele

Enset (Ensete ventricosum, Musaceae) ethnobotany: Research status, gaps and key messages ------51–62 Zemede Asfaw

Improving indigenous knowledge of propagation for the development of enset agriculture: Promoting farmers’ adaptation capacity to climate change ------63–73 Laila M.Karlsson, Abitew Lagibo Dalbato and Tamado Tana

Biotechnological studies on enset (Ensete ventricosum (Welw.) Cheesman)), a food security staple food crop of Ethiopia ------75–101 Genet Birmeta

Status and future prospects of research on diseases of enset (Ensete ventricosum) and their management ------103–119 Adane Abraham

Land-use changes in the enset-based agroforestry systems of Sidama, southern Ethiopia, and its implications for agricultural sustainability------121–132 Tesfaye Abebe

Diversity, challenges and management of enset (Ensete ventricosum (Welw.) Cheesman) by Kembatta people, southern Ethiopia ------133–161 Melesse Maryo, Sileshi Nemomissa and Tamrat Bekele

Achievements, experiences and strategies on enset (Ensete ventricosum (Welw.) Cheesman) research in Ethiopia ------163–189 Zerihun Yemataw, Sadik Muzemil, Agedew Bekele and Eshetu Derso

Relevant research questions on the crop physiology of enset ------191–199 P.C. Struik

A perspective to enhance innovative research with emphasis on varietal diversity and sustainable utilization of enset (Ensete ventricosum) ------201–209 Paul Wilkin, Aaron Davis, Sebsebe Demissew, Tom Etherington, Mark Goodwin, Pat Heslop-Harrison, Trude Schwarzacher and Kathy Willis

Addis Ababa declaration on enset ------211–213

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