Bananas Cell Death and Disease Resistance the Roots’ Health Support System Soil Fertility in East Africa Marketing Partnerships How to Contain Bacterial Wilt
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The International Journal on Banana and Plantain Spotlight on the banana congress Breeding better bananas Cell death and disease resistance The roots’ health support system Soil fertility in East Africa Marketing partnerships How to contain bacterial wilt Vol. 13 No.2 December 2004 InfoMusa Cover photo: Vol. 13 No.2 Banana worker in northern Peru. (Anne Vézina, INIBAP) INFOMUSA Vol. 13, No. 2 Publisher: International Network for the Improvement of Banana and Plantain Publishing director: Claudine Picq Editor: Anne Vézina Editorial Committee: Jean-Vincent Escalant, Richard Markham, Nicolas Roux, Charles Staver Layout: Crayon & Cie Printed in France ISSN 1023-0076 Editorial Office: INFOMUSA, INIBAP, Parc Scientifique Agropolis II, 34397 Montpellier Cedex 5, France. Telephone + 33-(0)4 67 61 13 02; Telefax: + 33-(0)4 67 61 03 34; E-mail: [email protected] Contents Subscriptions are free for developing countries readers. Article contributions and letters to the editor are welcomed. A review of conventional improvement strategies for Musa Articles accepted for publication may be Kodjo Tomekpe, Christophe Jenny and Jean-Vincent Escalant 2 edited for length and clarity. INFOMUSA is not responsible for unsolicited material, however, every effort will be made to Can model plants help banana improvement through biotechnology? respond to queries. Please allow three Martin B. Dickman 6 months for replies. Unless accompanied by a copyright notice, articles appearing in INFOMUSA may be quoted or reproduced Diseases and pests: A review of their importance and management without charge, provided acknowledgement Randy Ploetz 11 is given of the source. French-language and Spanish-language Population genetic structure and dispersal of Mycosphaerella fijiensis editions of INFOMUSA are also published. An electronic version is available at the Jean Carlier 17 following address: http://www.inibap.org/publications/infomusa/ Soil quality problems in East African banana systems and their relation infomusa_eng.htm To avoid missing issues of INFOMUSA, with other yield loss factors notify the editorial office at least six weeks in P.J.A. van Asten, C.S. Gold, S.H. Okech, S.V. Gaidashova, advance of a change of address. W.K. Tushemereirwe and D. De Waele 20 Views expressed in articles are those of the authors and do not necessarily New technologies to increase root health and crop production reflect those of INIBAP. Richard A. Sikora and Luis E. Pocasangre 25 Partnership and networking in the tropical fruit industry: the experience of the International Tropical Fruits Network Khairuddin Tahir 30 Focus on the Musa congress 32 Focus on bacterial wilt 38 The mission of the International Network for the Improvement of Banana and Plantain is Thesis 41 to sustainably increase the productivity of banana and plantain grown on smallholdings MusaNews 42 for domestic consumption and for local and export markets. INIBAP is a programme of the International Forum 46 Plant Genetic Resources Institute (IPGRI), a Future Harvest centre. In memory of Dr Maribona 48 InfoMusa - Vol. 13 - No.2 1 The banana congress up close Editorial We are pleased to offer you a special issue of INFOMUSA focusing on the First International Congress on Musa held in Malaysia from 6 to 9 July 2004. Organized by INIBAP and the Malaysian Agricultural Research and Development Institute (MARDI), the congress brought together some 250 delegates from all over the world, and from disciplines as far apart as genomics and fruit marketing, to share discussions and experiences under the theme Harnessing research to improve livelihoods. In addition to seven of the eight keynote addresses presented at the Congress (the one by Charles Staver on Farmer learning and plantain management in Nicaragua will be published in the June 2005 issue), this issue also contains a summary of the four sessions in the Focus on section. By publishing the keynote addresses so soon after the Congress, rather than filing them away while we prepare a formal proceedings that would be partly out of date by the time it is published, one of our aims is to reach a larger audience in a timely manner. We realize it is not a complete rendering of the Congress (the abstracts of the oral presentations and posters are available on our website, www.inibap.org). However, using INFOMUSA not only makes it possible to draw attention to the topical questions raised during those four days, it also provides an outlet to continue the discussion in our Forum section. We are also interested in your reaction to the format of the articles. Although this issue may seem to depart from INFOMUSA’s usual offering of scientific articles, in many ways it is not so different from past instalments. In the first years of its existence, the articles published in INFOMUSA were written in a more informal style than the scientific articles we currently publish, in keeping with its mission to inform readers “of INIBAP’s activities and present findings of the network”. But as stated in the first issue, INFOMUSA was also meant to “report on Musa research and activities worldwide”. Inevitably, at first, many of the articles were commissioned to our partners, but as the magazine became better known, submissions from researchers came to dominate its contents. As we are discovering with our survey, some readers would like a return to the less formal, some would say less scientific, and more newsy INFOMUSA. Others, however, would like to see it become a peer-reviewed journal. There is still time to let us know what you think by filling in the questionnaire on our website. We will be bringing you the results in the next issue. We will end with a few apologies. After urging our would-be authors to avoid jargon in their manuscripts, we were taken to task by people who answered the survey and were stumped by the expressions “upstream” and “downstream” research and “open-access” journal. By upstream research we mean the research done to develop innovative concepts and technologies, as opposed to downstream research, which integrates technology and knowledge in projects that have practical implications for farmers. Open-access journals are those that use a funding model that does not charge readers or their institutions for access. We also wish to apologise for suggesting, in the previous issue of INFOMUSA, that black leaf streak disease, caused by Mycosphaerella fijiensis, is now present in India. In the article “Evaluation of new banana hybrids against black leaf streak disease”, the disease against which the hybrids were evaluated was Sigatoka disease, caused by Mycosphaerella musicola. We regret the error. As far as we know, there has been no official record of black leaf streak disease in India. We are grateful to the vigilant readers who brought this to our attention. The editors InfoMusa - Vol. 13 - No.2 1 Genetic improvement A review of conventional improvement strategies for Musa Kodjo Tomekpe, Christophe Jenny and Jean-Vincent Escalant ost cultivated bananas are (EMBRAPA) works on bananas of the Pome triploids. Although triploidy confers and Silk sub-groups, which are highly prized M a certain vigour to the plant, it in that country. also contributes to the sterility that greatly limits the use of hybridization in banana The 3x/2x strategy improvement and constitutes a challenge Two factors were decisive in the development to conventional breeding methods. In spite of the 3x/2x strategy: the discovery of residual of these difficulties inherent in the banana female fertility in certain triploid cultivars crop, notable progress has been made on the one hand, and the observation of a over the last twenty years and it is not substantial proportion of tetraploids among unusual nowadays to find artificial hybrids their descendants on the other, due to the in various research stations, contributing to formation of unreduced triploid gametes that rural development, and even being grown on enable the conservation of the entire triploid family farms. genome. This strategy has been widely used This progress stems from several to try to create tetraploid hybrids resistant to conventional breeding programmes diseases and of good agronomic value by (Menendez and Shepherd 1975, Rowe pollinating susceptible triploids with male and Rosales 1992, Shepherd 1968, Soares fertile diploids that are resistant. Filho et al. 1992, Swennen and Vuylsteke The best-known examples of dessert 1990, Bakry and Horry 1992, Jenny et al. hybrid tetraploids from FHIA arose from 1994, Tomekpé et al. 1998). In Honduras, crosses between dwarf mutants of ‘Gros the Fundación Hondurena de Investigación Michel’ and ‘Prata’ and improved diploids Agricola (FHIA) is the oldest existing resistant to black leaf streak and Sigatoka programme and works on several dessert and diseases, and to the nematode Radopholus cooking bananas. It is the only programme similis. As to cooking bananas, one can to improve the ‘Gros Michel’ dessert banana. distinguish CRBP-39 from CARBAP and The FHIA has developed various types FHIA-21 (plantain hybrids) and BITA 3 from of hybrids, some of which are currently IITA (a cooking banana hybrid) all of which being distributed in several countries. In are resistant to black leaf streak and are France and in Guadeloupe, the Centre de currently being adopted by, or are already coopération internationale en recherche grown in, certain countries (Figure 1). agronomique pour le développement It should however be noted that nearly (Cirad) has concentrated for some twenty all the AAAB hybrids (resulting from years on the creation of new triploid dessert crosses between an AAB and an AA) can bananas for export, using a simple and show symptoms of banana streak disease original scheme based on a knowledge caused by the activation of viral sequences and exploitation of the existing diversity in integrated in the B genome of these cultivars. diploid dessert varieties (Bakry et al.