Genome-Wide Association Study Using High-Density SNP Chip Markers Revealed Novel Bacterial Panicle Blight (Burkholderia glumae) Resistance Genes in Rice

Bacterial panicle blight (BPB) is a serious rice disease that causes spikelet abortion and yield loss under high-temperature and humid conditions. To identify the genetic basis of BPB resistance, we performed a genomewide association study (GWAS) using 307 Korean rice cultivars. A significant quantitative trait locus (QTL), qBG6.1, was identified on chromosome 6, with a lead single nucleotide polymorphism surpassing the genome-wide significance threshold. Within this QTL, haplotype analysis based on whole-genome resequencing data from 157 accessions revealed two candidate genes significantly associated with the percentage of healthy seeds per panicle: Os06g0255900 and Os06g0259850. These genes encode proteins with functions related to exocyst-mediated vesicle trafficking (EXO70F5) and pathogen response (tobacco mosaic virus [TMV]-related protein), respectively, indicating their potential involvement in BPB resistance mechanisms. Our findings highlight the value of integrating GWAS and haplotype analysis to dissect complex traits such as disease resistance. Although the functional roles of these candidate genes require further validation, they represent promising targets for molecular breeding and future genetic studies aimed at developing BPB-resistant rice cultivars.