Genome-Wide Association Study of Submergence Tolerance in Rice (Oryza sativa L.)

Submergence damage to rice was reported as one of the major problems in rainfed lowland areas where the water remains. This study assessed the submergence tolerance of core collection during the seedling stage of the rice using dry seeds. Also, genome-wide association study (GWAS) combined with principal component analysis (PCA) and kinship matrix analysis was performed to identify quantitative trait loci (QTL) for submergence tolerance. Through this GWAS analysis, nine lead SNPs were confirmed to be associated with submergence tolerance, and a linkage disequilibrium (LD) decay analysis identified the 230 kb exploratory range for the detection of QTLs and candidate genes. Nine QTL were detected, on chromosomes 3 (qSUB3), 4 (qSUB4), 6 (qSUB6-1 and qSUB6-2), 11 (qSUB11-1, qSUB11-2 and qSUB11-3), and 12 (qSUB12-1 and qSUB12-2). Two candidate genes (Os03g0679300 and Os11g0517800) in the two QTL regions associated with submergence tolerance were detected. The results of this study provide associated SNPs in candidate genes for submergence condition and strategies for developing submergence condition in breeding programs.