Genome-wide association study reveals novel genetic loci involved in anaerobic germination tolerance in

Increasing numbers of rice farmers are adopting methods of direct seeding in flooded paddy fields to save costs associated with labor and transplanting. Successful seedling establishment under anoxic conditions requires rapid coleoptile growth to access oxygen near the water surface. It is important to identify relevant genetic loci for coleoptile growth in rice. In this study, the coleoptile length (CL), coleoptile surface area (CSA), coleoptile volume (CV), and coleoptile diameter (CD) of a germplasm collection consisting of 200 cultivars growing in a low-oxygen environment for 6 days varied extensively. A genome-wide association study (GWAS) was performed using 161,657 high-quality single nucleotide polymorphisms (SNPs), which were obtained via genotyping by sequencing (GBS). A total of 96 target trait-associated loci were detected, of which 14 were detected repeatedly in both the wet and dry seasons. For these 14 loci, 384 genes were located within a 200-kb genomic region (± 100 kb from the peak SNP). In addition, 12,084 differentially expressed genes (DEGs) were identified using transcriptome expression profiling. Based on the GWAS and expression profiling, we further narrowed the candidate genes down to 111. Among the 111 candidate DEGs, Os02g0285300, Os02g0639300, Os04g0671300, Os06g0702600, Os06g0707300, and Os12g0145700 were the most promising candidates associated with anaerobic germination. In addition, we performed a detailed analysis of Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-022-01345-1.