Genome-Wide Association Study of Blast Resistant in Korean Rice (Oryza sativa L.) Breed Lines

A total of 857 rice breed lines were used to evaluate rice blast resistance. Frequency of leaf spot index was skewed to theright of the 1-9 scale in bar plot, with a score of 7 showing the highest frequency. The average spot index score of 857 breed lines was5.33. Associations showing higher than the threshold of -log10(P) = 5.17 were detected as significant associations. Significantlyassociated single nucleotide polymorphism (SNP) markers located within ± 250 kb on the lead SNP position was designated to one QTLlocus of lead SNP markers. Five association loci were detected. Two associated QTLs detected on Chr. 4 were designated as qRB4.1and qRB422, explaining 17.8% and 14.3% of total phenotypic variations, respectively. Associated QTLs detected on Chr. 1, 11, and 12(one each) designated as qRB1, qRB11 and qRB12 explained 44.6%, 9.09%, and 13.7% of total phenotypic variations, respectively. Wecompared previously reported QTLs. The location of qRB4.2 was overlapped with the previously reported QTL for blast fieldresistance. The location of qRB12 was also overlapped with the field resistance leaf blast. The other one, qRB4.1, was overlapped withbacterial blight resistance.