Rice has been cultivated in western and central Africa for centuries and is now a staple food in the region. But drought is a major problem as it severely depresses yield in upland and rainfed lowlands, where most of the producers are resource-poor farmers. Drought resistance in plants, however, is a complex trait, controlled by the interaction of many genes, as it involves several physiological, phonological and morphological mechanisms. Consequently, conventional breeding for drought resistance in Africa has had but limited success. DNA markers and genetic mapping are expected to provide impetus not only in gaining a better understanding of the traits associated with drought but also by contributing to enhanced selection efficiency.

The project seeks to 1) characterize drought in different environments and identify the most important traits associated with drought resistance, 2) select and characterize sources of drought resistance for genetic mapping and quantitative trait locus (QTL) analysis, and 3) develop advanced lines combining drought resistance with heavy yield and agronomic and quality characters acceptable to farmers and consumers. To achieve these objectives the project will exploit a core germplasm pool (Oryza glaberrima and O. sativa) of 1) drought-resistant O. glaberrima accessions, collected and screened in Mali by the Institut d’Economie Rurale (IER), 2) drought-tolerant interspecific breeding lines developed by the Africa Rice Centre (WARDA) from crosses between O. glaberrima and O. sativa, and 3) a range of traditional O. glaberrima and O. sativa accessions from WARDA’s gene bank. Confirmed sources of resistance among this core germplasm will be crossed with elite but drought-susceptible O. sativa lines to develop interspecific and intraspecific populations segregating for drought resistance. These populations will be phenotyped in replicated field trials in different environments in Mali and Nigeria. QTL analysis will be performed to identify, across environments, drought-improving alleles for future breeding. In other populations, selection will be conducted to generate agronomically superior drought-resistant lines.