This study was conducted to identify quantitative trait loci (QTL) related to grain qualities under high temperature during ripening stage using 187 Korean rice varieties. To analyze grain qualities under high temperature during ripening stage, grain appearance such as head rice and chalky grains percentage and physicochemical characteristics were investigated and SNP genotyping of 187 Korean varieties was conducted for association analysis related with grain qualities under high temperature. Five traits exhibited continuous distributions in the non-glutinous Korean varieties, indicating that these traits are controlled by multiple genes. Association mapping among non-glutinous Korean varieties was conducted using 223 markers showed polymorphism among 384 SNP markers. Six QTLs for chalk grains percentage were mapped to chromosomes 1, 4, 10 and 11. These six QTLs were linked to the SNP marker id1014176 on chromosome 1, id4010924 on chromosome 4, id10000644 on chromosome 10 and id11011505 on chromosome 11, and explained approximately 21, 61, 50, 23, 23 and 21% of the total phenotypic variance. Four QTLs for head rice percentage in chromosomes 4, 10 explained the total phenotypic variance by over 47% and around 20%. Fifteen QTLs for RVA characteristics including hot paste viscosity, peak viscosity and setback viscosity were mapped to chromosome 1, 6, 7, 12 and QTLs were explained around 20% of the total phenotypic variance.

• Jeong-Ju Kim(Rice Breeding and Cultivation Research Division, NICS, RDA) Corresponding Author
• Young-Jun Mo(Rice Research Division, NICS, RDA)
• Woon-Cheol Shin(Sangju Sub-Station, NICS, RDA)
• Ki-Young Kim(Rice Breeding and Cultivation Research Division, NICS, RDA)
• Jeom-Ho Lee(Rice Breeding and Cultivation Research Division, NICS, RDA)