Genome Wide Association Study of Rice (Oryza sativa L.) during Heading Stage under a High Temperature

At the reproductive development stage of rice (Oryza sativa L.), temperature stress can decrease spikelet fertility, ultimately resulting in a yield loss. In this study, a total of 98 rice varieties were used in genome-wide association study (GWAS) to understand spikelet fertility under a high temperature (SFHT). GWAS results revealed that two lead SNPs were significantly associated with SFHT. Candidate genes located within ± 250 kb of the corresponding SNP position were discovered, resulting in a total of 21 candidate genes on chromosome 10 and 18 candidate genes on chromosome 11. Based on previously reported function and haplotype analysis, Os10g0177200 (EF-HAND 2domain containing protein) as one candidate gene showed significant differences among groups of haplotypes. This candidate gene will be further evaluated for its function to determine whether it is useful for improving molecular breeding studies and developing new high temperature tolerant rice varieties.