Nature of taro (Colocasia esculenta (L.) Schott) genetic diversity prevalent in a Pacific Ocean island, Vanua Lava, Vanuatu

Caillon Sophie, Quéro Garcia José, Lescure Jean Paul, Lebot Vincent. 2006. Nature of taro (Colocasia esculenta (L.) Schott) genetic diversity prevalent in a Pacific Ocean island, Vanua Lava, Vanuatu. Genetic Resources and Crop Evolution, 53 (6) : 1273-1289.

Résumé : Taro (Colocasia esculenta (L.) Schott), cultivated in Vêtuboso, a village of northern Vanuatu, Melanesia, was surveyed to: (I) assess the extent of morphological and molecular variation being maintained by growers at the village level and, (2) compare this diversity with the diversity found in the crops in Vanuatu. Ethnobotanical data were combined with AFLP analysis to elucidate possible sources of variation. Folk assessment of variation is based on: (a) morphological characteristics (11 characters), (b) names and (c) classification according to habitat, uses, origin and agronomic adaptation. This 3-fold approach allowed growers to differentiate 96 morphotypes, all of which are given distinct vernacular names. AFLP finger-prints successfully differentiated all these 96 morphotypes which do not present a significant intra-clonal variation. But genetic results showed no clear groupings according to geographic origin or habitat of morphotypes and stated that the diversity found within the village was comparable with the overall diversity found in Vanuatu. Local nomenclature and stories associated with each cultivar suggested' three sources of diversity: introductions (38%), somatic mutations (15%) and sexual recombinations (48%). AFLP results confirm folk beliefs about origin at least for three pairs of mutants. The 11 so-called wild forms analysed by AFLP were suggested to be feral, escapes from domestication. A dynamic in situ conservation strategy (DISC), favouring a broadening of the national genetic base, was discussed for taro.

Mots-clés Agrovoc : Colocasia esculenta, taro, ressource génétique, biodiversité, reproduction sexuée

Mots-clés géographiques Agrovoc : Vanuatu

Mots-clés complémentaires : AFLP

Classification Agris : F30 - Génétique et amélioration des plantes

Champ stratégique Cirad : Axe 1 (2005-2013) - Intensification écologique

Auteurs et affiliations

• Caillon Sophie, Université d'Orléans (FRA)
• Quéro Garcia José, IRD (FRA)
• Lescure Jean Paul, IRD (FRA)
• Lebot Vincent, CIRAD-FLHOR-UPR Multiplication végétative (VUT)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/534955/)

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