Quantitative and Health Evolution of National Yam Genetic Resources under Ex Situ Conservation in Côte d’Ivoire

Abstract

Yam, of the genus Dioscorea, is an important crop grown mainly in tropical West Africa. In Côte d’Ivoire, yam is the most important food crop and contributes to food security with an annual production of 8 million tonnes. To preserve the genetic variability of the national yam collection, a series of selection and breeding projects have been carried out at the Centre National de Recherche Agronomique (CNRA). This study involved analysing quantitative evolution and assessing the incidence of diseases and pests in the yam accessions in the collection. After analysis, it was found that of the 441 accessions in 2022 (214 Dioscorea alata , 178 Dioscorea rotundata , 8 Dioscorea esculenta , 2 Dioscorea bulbifera and 2 Dioscorea dumetorum ), 303 came from Côte d’Ivoire (69%), 108 from IITA in Nigeria (24%) and 30 accessions (7%) from various origins. The number of yam accessions in the national collection varied from 513 in 2011 to 441 in 2022. A loss of 72 accessions was observed in 2022. This shows that the national yam genetic resources come from different origins and have undergone a discontinuous evolution marked by the loss of 72 accessions between 2011 and 2022. However, these losses were compensated for by the collections and varietal creations carried out during these years. From a health point of view, there were two diseases: anthracnose and Yam Mosaic Virus. These diseases had a negative impact on genetic resources.