Major QTLs for eating quality of an elite Japanese rice cultivar, Koshihikari, on the short arm of chromosome 3

摘要

To identify the chromosomal regions controlling the eating quality of Koshihikari rice, we performed a quantitative trait locus (QTL) analysis using two backcross inbred lines (BILs): N-BILs (79 lines derived from a cross of Nipponbare/Koshihikari//Nipponbare) and K-BILs (89 lines derived from a cross of Nipponbare/Koshihikari//Koshihikari). We evaluated several components of the eating quality of cooked rice, namely glossiness, taste, stickiness, hardness, and overall evaluation, based oil sensorytests by a trained panel, and amylose and protein contents. Ten QTLs for these components were detected in N-BILs (two regions of chromosome [chr.] 3 and one of chr. I I), and six in K-BILs (chr. 3 and chr. 6). Each QTL explained 11.6% to 32.0% of the total phenotypic variance. QTLs at the distal end of the short arm of chr. 3 were commonly identified in both BILs. The Koshihikari alleles at these QTLs increased eating quality. The genetic effect of the Koshihikari alleles was confirmed by analysis ofa chromosome segment Substitution line containing a Koshihikari segment of the short arm of chr. 3 in the Nipponbare background.