Ph.D. Student ICAR-INDIAN AGRICULTURAL RESEARCH INSTITUTE NEW DELHI, Delhi, India
Body of Abstract: For more than 50% of world’s population, rice serves as a major source of calorific intake playing a key role procuring food security in Asia, Africa and Americas. By the end of this century, global air temperature may exceed 1.5 to 2°C which along with increased recurrence of extreme high temperature events would lead to decrease in rice yield in the 2nd half of the century. The reproductive stage in rice is particularly sensitive to high temperature affecting pollination, pollen germination that causes sterility in the spikelet leading to significant yield loss. In this context, identification of efficient genotypes and introgression of candidate genes in the cultivated varieties is utterly important and seems a way to restrain significant yield losses. Spikelet fertility and panicle weight were investigated for two years in a set of 241 rice genotypes sequenced under 3000 rice genomes project, under natural and controlled environmental conditions. High temperature significantly reduced the spikelet fertility and panicle weight. Genome wide association mapping was performed on spikelet fertility and panicle weight with 1 million SNPs using an efficient mixed model. A total of 124 QTLs were found associated with spikelet fertility and 135 QTLs with panicle weight under high temperature stress. Putative candidate genes and their haplotype variants have been identified. The work facilitates developing haplotypes, haplotype networks, haplotype specific markers and identification of genotypes carrying superior haplotypes. The identified haplotypes could be beneficial for marker-assisted breeding and making reproductive stage high temperature stress tolerant rice.