Resequencing of a Core Rice Mutant Population Induced by Gamma-Ray Irradiation and Its Application in a Genome-Wide Association Study

A total of 2561 gamma ray-induced mutants (M 7 ) were evaluated in six abiotic stress treatments, and then principal component analysis was performed to score their phenotypes. Resequencing was performed on 123 selected rice mutants and wild-type rice to assess the structural changes in the genomes of these mutants, such as single nucleotide polymorphisms (SNPs) and insertion/deletion (InDels). A total of 5160 (avg. 87.3 per plant) SNPs and 7195 (avg. 121.9) InDels were observed in the 200-Gy lines, whereas 5650 (avg. 88.3) SNPs and 7676 (avg. 119.9) InDels were found in the 300-Gy lines. We found that one candidate gene ( Os02g0528900 , which is similar to the gene for pleiotropic drug resistance (PDR)-like ATP-binding cassette (ABC) transporter) contained two SNPs that were included in principal component 4 via a genome-wide association study. The 300-42 line had the lowest phenotype score against heat, possibly suggesting the existence of a relationship between these SNPs and heat stress. Co-expression analysis of the candidate gene involved in responses to toxic substances and the chemical stimulation of significant biological processes. Therefore, the studied targeting induced local lesions in genome (TILLING) population could be a useful source of mutations in the breeding of new genetic resources for forward and reverse genetics.