Résumé
Yams, belonging to the genus Dioscorea, family Dioscoreaceae, are an important food crop in tropical and subtropical regions (Ayensu and Coursey, 1972). Yam plants are dioecious monocotyledonous vines, cultivated for their starchy tubers. Yam is a multi-species, polyploid, and vegetatively propagated crop, exclusively propagated by means of “setts,” small tubers or small pieces of tuber.