Dynamic management of genetic resources of Allium cepa L (onion) in west Africa

Varieties grown in small scale farmers' conditions in West Africa should be improved for increasing the yields, storage life of bulbs and removing the bolting habit. Local populations could harbour genetic diversity for these traits and thus could help in improving the schemes on onions in this area. In this aim, the exploitation of genetic variability of local populations is necessary because they could have favourable alleles from these agronomic traits. Onion germplasm collecting has been carried out in six countries in west Africa. These local varieties have been evaluated for both agro-morphological traits and allozyme diversity. The genetic diversity structure allowed the identification of three groups based on bulb productivity and earliness. Each group could be used as a source of material in breeding programmes. Furthermore, these results allow the definition of strategies for conservation and use of genetic resources in West Africa with a special emphasis on dynamic management.