Bioversity and domestication of yams in West Africa: Traditional practices leading to Dioscorea rotundata Poir.

The domestication of wild yams is still common practice in West Africa. It also offers one of the few remaining opportunities to understand how farmers use their empirical knowledge to tap the genetic resources of wild plants and create products suitable for agriculture. Yam agronomists and breeders have, until recently, focused little attention on this process of organizing and generating agrobiodiversity. This book aims to fill the gap by pooling existing knowledge on the subject. This original field offers a wealth of prospects for scientific progress at a time when scientists are becoming increasingly aware of the fact that local farmers' knowledge and practices relating to genetic resource management substantially enhances the potential for technical progress and adaptation to environmental change. The focus is deliberately only on domestication leading to Dioscorea rotundata yams, the type most widely cultivated in West Africa. Several chapters are devoted to the biodiversity of Dioscorea rotundata yams and the wild form they derive. The authors conclude by putting forward hypotheses to explain the phenotype transformations induced by domestication practices and their maintenance by vegetative propagation. Further research, especially by geneticists, is needed to confirm these hypotheses. Some are already being assessed, using the most advanced molecular markers analysis techniques, by joint teams of scientists from developed and developing countries.