Résumé
Rice is the most important food crop of the developing world. Whilst rice demand is increasing continuously, rainfed rice farmers in most African countries still harvest around one ton grain per hectare. Their crops, mainly Oryza sativa, are affected by multiple stresses and pests. Oryza glaberrima appeared to be more adapted to these constraints. Although not highly productive, and threatened by extinction, O.glaberrima cultivars continue to be cultivated by many resource-poor farmers because of its grain quality and yield stability. In the early nineties, using O.glaberrima (accession CG14) as donor, breeders at the West African Rice Development Association (WARDA), created many backcrossed introgressed lines O.sativa/glaberrima exhibiting several adaptive traits in the field, assumed to come from O.glaberrima. We are currently constructing a CG14 genomic library at the Centre de Coopération Internationale en Recherche Agronomique pour le développement (CIRAD) using a transformation-competent artificial chromosome (TAC) vector system (pYLTAC17). We aim at generating 36,864 clones representing at least 10 genome equivalents coverage. This library should benefit all marker-assisted selection breeding programs using O. glaberrima as a donor of useful genes for biotic and abiotic traits. Once constructed and as a first application, this library will be exploited for the cloning of the first nematode resistance gene mapped in rice. Screening and clone distribution will be ensured by the John Innes Centre (JIC) Genome laboratory as a worldwide service on a cost-recovery basis for public use. This project, funded by the Rockefeller Foundation and CIRAD, is a collaboration between JIC, CIRAD and WARDA. (Texte intégral)