No abstract

Drought stress is a serious constraint, especially in rainfed rice production, and breeding for drought tolerance by selection based on yield under stress, though effective, is slow. Mapping quantitative trait loci (QTLs) for yield and its components under drought stress predominant in rainfed target populations of environment (TPE) will help overcome this limitation. In the present study, a subset of 143 F 8 and F 9 recombinant inbred (RI) lines derived from IR62266-42-6-2 (IR62266), a high-yielding indica ecotype and Norungan, a landrace from TPE, was used to map QTLs for yield and its components under drought predominant in TPE. A large effect yield QTL observed under drought stress in TPE was consistent across two years with a phenotypic variation of 31.3% and 37.9% and additive effect of 629.2 and 424.9 kg/ha. Further, this region was fine-mapped to 94.0 kb with positive effect on grain yield under stress.