Breeding for drought tolerance: A major challenge for rice cultivation under water limiting conditions

Abstract

Rice is a drought-susceptible crop because of its shallow root system, rapid stomatal closure and little epicuticular wax on the leaves. It is highly sensitive to drought stress at the reproductive stage. The reduction in grain yield under drought stress is mainly caused due to the sterility of spikelet at maturity. Deep and thick root systems have been correlated with better grain yield under drought stress in rice. Many QTLs have been identified under upland and rainfed lowland conditions for various root traits as well as grain yield under drought stress. The successful introgressions of these QTLs through Marker Assisted Breeding (MAB) followed by precise phenotyping have resulted in the development of several drought tolerant varieties. To be more effective, the breeding programme should aim at introgressing QTLs for root traits as well as grain yield under drought stress for development of drought tolerant high yielding rice variety.