Delhi, India "Waterproof" versions of popular varieties of rice, which can withstand 2 weeks of complete submergence, have passed tests in farmers' fields with flying colors. Several of these varieties are now close to official release by national and state seed certification agencies in Bangladesh and India, where farmers suffer major crop losses because of flooding of up to 4 million tons of rice per year. This is enough rice to feed 30 million people.
The flood-tolerant versions of the "mega-varieties"high-yielding varieties popular with both farmers and consumers that are grown over huge areas across Asiaare effectively identical to their susceptible counterparts, but recover after severe flooding to yield well.
A 1-9 November tour of research stations and farms in Bangladesh and India led by David Mackill, senior rice breeder at the International Rice Research Institute (IRRI), marked the successful completion of a project, From genes to farmers' fields: enhancing and stabilizing productivity of rice in submergence-prone environments, funded for the past 5 years by Germany's German Federal Ministry for Economic Cooperation and Development (BMZ).
The new varieties were made possible following the identification of a single gene that is responsible for most of the submergence tolerance. Thirteen years ago, Dr. Mackill, then at the University of California (UC) at Davis, and Kenong Xu, his graduate student, pinpointed the gene in a low-yielding traditional Indian rice variety known to withstand flooding. Xu subsequently worked as a postdoctoral fellow in the lab of Pamela Ronald, a UC Davis professor, and they isolated the specific genecalled Sub1Aand demonstrated that it confers tolerance to normally intolerant rice plants. Dr. Ronald's team showed that the gene is switched on when the plants are submerged.
A geneticist from UC Riverside, Julia Bailey-Serres, is leading the work to determine exactly how Sub1A confers flo
|Contact: Adam Barclay|
International Rice Research Institute