A. Dansi, H.D. Mignouna, A. Sangare, J. Zoundjihékpon, R. Asiedu and F.M. Quin
Using IPGRI’s descriptors, 560 accessions of cultivated yams (D. cayenensis / D. rotundata complex) collected throughout Benin, were characterised. Ninety morphotypes were identified and further classified into 26 cultivar groups based on their morphological similarities. The geographical distribution of cultivar groups is presented and two centers of diversity were identified. The flowering and the fruiting capacity of the morphotypes and the ploidy level of some accessions were evaluated and will allow better planning of crosses in breeding programs. Isozyme analysis was also earned out in order to refine the classification based on morphological characters. For some groups, mainly Kokorogbanou, the markers used were not efficient for genotype identification, showing the need to resort to DNA fingerprinting. An on-farm conservation strategy is proposed, based upon the centers of diversity which this study identified. Adoption of this strategy could assist the sustainable conservation of cultivated yam genetic resources and also enhance the extent of genetic diversity that farmers could utilise. Additional proposals concern in situ conservation of the wild yam species and participatory breeding.