Screening and identification of rice genotypes for drought tolerance at reproductive stage under rainfed lowland condition

A field screening of twelve rice genotypes under drought stress and irrigated non-stress condition was conducted during kharif 2013 with the objective to study the effect of drought stress on yield and yield attributes performance of advanced breeding lines and current high yielding varieties. The effects of water deficit on various physiological traits associated with drought tolerance were also studied. Result revealed that significant yield decline was observed almost in all rice genotypes grown under water stress condition compared to irrigated situation. Out of these twelve rice genotypes, IR88964-24-2-1-4, IR88966-43-1-1-4 and IR88964-11-2-2-3 showed superior in terms of grain yield and yield attributes. Significant variation was also observed among genotypes for leaf rolling, leaf drying, stress recovery and relative water content under drought stress conditions. The tolerant lines maintained high leaf water status, membrane stability and plant biomass under reproductive stage drought condition. Based on yield and yield attributes results under drought and irrigated condition, rice genotypes IR88964-24-2-1-4, IR88966-43-1-1-4 and IR88964-11-2-2-3 were recommended for use in drought breeding programme as well as adoption in rainfed lowland ecosystem. The present study also indicates the agro-morphological and physiological traits that have direct and indirect effect on yield performance of rice genotypes under drought stress condition