Wonder Rice Initiative for Food Security and Health (WISH) Project: Identification of genes associated with useful agronomic traits and their use in breeding for sub-Saharan Africa

In many countries in sub-Saharan Africa (SSA), rice consumption has risen sharply since the 1990s, especially in urban areas. However, domestic rice production is insufficient to meet the increased demand, resulting in a demand-supply gap of about 12 million tons per year. Increasing rice production is a major food security concern in these countries. However, average rice yield in the region is only 2.1 t ha-1 , about half that of Asia. To increase rice production in SSA, it is essential to breed high-yielding varieties that are adapted to the environment of each rice-growing region and to maximize the production potential of each region. Since the sequencing of the rice genome was completed in 2004, many genes associated with useful agronomic traits have been identified. By using molecular markers linked to genes involved in agronomic traits, rice plants with desired beneficial alleles can be selected without phenotypic evaluation. However, in the developing countries of SSA, such advanced information is not widely used in rice breeding. Based on the results of our basic research on the identification, cloning and functional analysis of genes controlling yield-related traits (such as number of grains and number of primary rachis branches per panicle) and disease resistance (blast and bacterial blight) in rice, we have developed about 300 WISH lines, using marker-assisted backcrossing to introduce genes for increased grain number (Gn1a), increased number of primary rachis branches (WFP) and blast resistance (pi21) into varieties favored by farmers in Asia and Africa and tolerant to abiotic stresses. Universities and agricultural research institutes in Kenya, Vietnam, Myanmar, and Colombia have received these WISH lines. Cultivation trials in Kenya have revealed that the NERICA 1 lines introgressed with Gn1a and WFP have the potential to improve rice productivity, and lines of Basmati 370 carrying Ctb1 have improved cold tolerance at the reproductive stage. We are now in the process of registering these lines as new varieties for Kenya. In the future, we aim to make WISH lines available to other parts of SSA to increase rice production.