Phenotypic biodiversity of an endemic wild pear, Pyrus mamorensis Trab., in North- Western Morocco using morphological descriptors Asma Ait Said, Ahmed Oukabli, Fatima Gaboun, Marie Hélène Simard & Cherkaoui El Modafar Genetic Resources and Crop Evolution An International Journal ISSN 0925-9864 Genet Resour Crop Evol DOI 10.1007/s10722-012-9889-4 1 23 Your article is protected by copyright and all rights are held exclusively by Springer Science +Business Media Dordrecht. This e-offprint is for personal use only and shall not be self- archived in electronic repositories. If you wish to self-archive your work, please use the accepted author’s version for posting to your own website or your institution’s repository. You may further deposit the accepted author’s version on a funder’s repository at a funder’s request, provided it is not made publicly available until 12 months after publication. 1 23 Author's personal copy Genet Resour Crop Evol DOI 10.1007/s10722-012-9889-4 RESEARCH ARTICLE Phenotypic biodiversity of an endemic wild pear, Pyrus mamorensis Trab., in North-Western Morocco using morphological descriptors Asma Ait Said • Ahmed Oukabli • Fatima Gaboun • Marie He´le`ne Simard • Cherkaoui El Modafar Received: 16 April 2012 / Accepted: 23 July 2012 Ó Springer Science+Business Media Dordrecht 2012 Abstract In this paper, we report on morphological The results demonstrated high levels of morphological diversity, ecology and flowering phenological records variation in the sampled accessions of P. mamorensis of an endangered and an endemic species of Morocco and established the relationships among the local Pyrus mamorensis Trab. For this study, a survey was germplasm using the UPGMA cluster analysis and the undertaken in North-Western Morocco (Mamora factorial discriminant analysis. Furthermore, we were forest and Zae¨r region) whereby 67 accessions of able to distinguish three types of flowering in the P. mamorensis were sampled. A set of 33 genotypes of Mamora forest: early, intermediate and late flowering Pyrus spp. from the international collection INRA- type. Otherwise, the UPGMA classification compar- Angers (France) of the genus Pyrus were also ing local accessions of P. mamorensis to the interna- analyzed. The variability of the total of 100 accessions tional collection led to the formation of four major was assessed by twenty-six characters including groups showing the closest correspondence to their fourteen qualitative and twelve quantitative traits. geographical origins: (1) The North African species represented by P. mamorensis, (2) The East Asian pea species, (3) The West Asian species and (4) The European species. These findings suggest the impor- A. Ait Said Á C. El Modafar tance of implementing a conservation strategy pre- Laboratoire de Biotechnologie Valorisation et Protection serving the genetic resources of wild pear in des Agroressources, Faculte´ des Sciences et Techniques Gue´liz, Universite´ Cadi Ayyad, B.P. 549, 40 000 North-Western Morocco. Marrakech, Morocco Keywords Factorial discriminant analysis Á & A. Ait Said Á A. Oukabli ( ) Genetic conservation Á Morphological diversity Á UR Ame´lioration des Plantes et Conservation des Ressources Phytoge´ne´tiques, INRA, B.P. 578, Phenological records Á Pyrus mamorensis Trab. Á Mekne`s, Morocco UPGMA classification e-mail: [email protected] A. Ait Said Á M. H. Simard UMR GenHort INRA-INH-UA, Unite´ d’Ame´lioration des Espe`ces Fruitie`res et Ornementales, 42 Rue G. Morel, Introduction B.P. 60057, 49071 Beaucouze´ Cedex, France The genus Pyrus belongs to the subfamily Maloideae F. Gaboun UR Biotechnologie, CRRA, INRA, B.P. 415, in the family Rosaceae. The origin of the genus is Rabat, Morocco considered to be in the mountainous area of western 123 Author's personal copy Genet Resour Crop Evol China and is known to evolve and spread eastward and Materials and methods westward (Challice and Westwood 1973; Hummer and Postman 2003). In spite of the wide geographic Analyzed populations and sampling distribution of Pyrus, species are intercrossable and there are no major incompatibility barriers to inter- Field expeditions were started in 2008 with the aim of specific hybridization (Westwood and Bjornstad collecting P. mamorensis accessions throughout 1971). Furthermore, the narrow morphological diver- North-Western Morocco. Sites were selected on the sity and the lack of distinguishing characters among base of indigenous information and previous literature species have been reported (Westwood 1982; Voltas (Fennane and Ibn Tattou 1998; Fennane et al. 1999). et al. 2007). Therefore, classification of pear species is Collections were made from wild habitats which were very problematic and is often confusing and giving concentrated in two principal regions: The Mamora similar taxa designated as different species by some forest and Zae¨r region. A total of 67 accessions of authors (Aldasoro et al. 1996). Twenty-two main P. mamorensis (consisting each of an individual tree) species have been reviewed and listed by Challice and collected according to population’s size were sam- Westwood (1973) with their geographical origins. It pled: 56 from the Mamora forest and 11 from Zae¨r was reported also that Pyrus has natural occurrences in region. Trees were chosen randomly, with no pheno- the wild state in Europe, temperate Asia and moun- typical selection, and were at least 50 m away from tainous areas of northern Africa. each other to avoid sampling from related individuals. Among these species, Pyrus mamorensis Trabut Within the fieldwork, the accessions were located with (1916), a wild pear endemic to Morocco has been a hand-held global positioning system (GPS). Loca- mentioned. Commonly called ‘Njache’, this tree tion information of the sampled stands is provided in grows spontaneously in the plains and low mountains. Table 1. Fennane et al. (1999) classified P. mamorensis as a Furthermore, a set of 33 genotypes of Pyrus spp. rare wild tree. This later was reported by Fennane and from the international collection of the genus Pyrus Ibn Tattou (1998) in the North-Western Morocco and held in the research station INRA-Angers were used especially in the Cork-oak forests such as the Mamora (Table 2). forest. It’s the only spontaneous arborescent species Traits were measured and evaluated separately on a associated with Quercus suber L., in scattered or representative population of leaf-shoot and fruit. For grouped trees (Metro and Sauvage 1955). However, each accession and for each character studied, we these ecosystems seem to undergo a very strong made 15 individual measurements. A sample of 15 regression due to the combined effect of overgrazing, adult leaves, 15 one-year-old shoots and 15 mature drought, and reforestation (Bakry 1996; Belghazi et al. fruits per tree were evaluated and measured using a 2008). Under these conditions, the potential of natural caliper. All of them were taken from all tree orienta- regeneration of wild species is decreasing rapidly. tions and middle parts of shoots, and only healthy and Until now, no investigation on the morphological undamaged ones were selected. characterization of P. mamorensis in Morocco was made. Therefore, it is necessary to assess the wild Morphological descriptors genetic diversity of this local species in order to establish an ex situ collection and to prevent its genetic A total of 26 morphological characters including 14 erosion. binary or multistate traits and 12 quantitative variables The main objectives of the present study were (1) to were analyzed, following both the guidelines of the assess the genetic diversity present at the morpholog- International Union for the Protection of New Vari- ical level within and among two populations of wild eties of Plants (UPOV 2000) and the Descriptor List P. mamorensis in North-Western Morocco; (2) to for Pear of the Commission of European Communities compare the local accessions of P. mamorensis to the and the International Plant Genetic Resources Institute international collection of Pyrus maintained in the (CEC and IPGRI 1983). Some relevant traits for the research station INRA-Angers (France) and (3) to identification of wild forms, such as presence of thorns investigate the usefulness of morphological characters on young shoots or leaf hairiness, were also added in the classification of Pyrus species. (Wagner 1995). The analysis included three characters 123 Author's personal copy Genet Resour Crop Evol Table 1 Informations on P. mamorensis stand’s location in North-Western Morocco Species Stand Number of Region Latitude Longitude accessions (°N) (°W) Pyrus mamorensis Ait Malek 8 Mamora forest, canton D 33.58 6.25 Sidi Bou azza (Oued Tiflet) 2 Mamora forest, canton D 34.03 6.21 Aı¨n Johra (Hefrat N’Jach) 11 Mamora forest, canton C 34.06 6.21 Ch’abat Awid al Ma 11 Mamora forest, canton C 34.04 6.18 Sidi Qaddour 6 Mamora forest, canton C 34.06 6.23 Sidi Allal Bahraoui (Sale’s route) 10 Mamora forest, canton B 34.02 6.33 Dayet Al Haı¨la (Kenitra’s route) 8 Mamora forest, canton A 34.09 6.35 Had Laghoualem 11 Zae¨r 33.22 6.41 Table 2 List of Pyrus spp. Species Acronym Number Genotype code from the international of accessions collection INRA-Angers (France) used as reference Pyrus communis L. PC 5 P10-1; P11-2; P2395; P2420; P5-1 samples in this study Pyrus betulaefolia Bge. PB 5 P1587; P2419; P252; P2631; P3502 Pyrus calleryana Decne. PCal 5 P1541; P2418; P2445; P3311; P3313 Pyrus syriaca Boiss. PS 4 P2400; P2403; P2635; P3515 Pyrus nivalis Jacq. PN 4 P1967; P1990; P2470; P2472 Pyrus persica Pers. PaP 2 P251; P264 Pyrus amygdaliformis Vill. PA 1 P257 Pyrus salicifolia Pall. PSal 1 P1851 Pyrus elaeagnifolia Pall. PE 1 P1588 Pyrus cordata Desv. PcC 1 P3511 Pyrus longipes Coss. et Dur. PL 1 P1855 Pyrus pashia Ham. ex D. Don PP 1 P707 Pyrus malifolia Spach PM 1 P463 Pyrus gharbiana Trab.