Mapping quantitative trait loci underlying appearance quality of rice grains (Oryza sativa L.).

Ninety-eight backcross inbred lines (BILs) derived from a subspecific cross of Nipponbare (japonica)/Kasalath (indica)//Nipponbare and its genetic linkage map were used to identify quantitative trait locus (QTL) controlling rice appearance quality traits such as grain length (GL), grain width (GW), length-width ratio (LWR), percentage of grains with chalkiness (PGWC), square of chalky endosperm (SCE), degree of endosperm chalkiness (DEC) and grain endosperm transparency (GET) by composite interval mapping over two years. A total of 33 QTLs were identified to be significant in at least one year for seven traits and the number of QTL for each trait ranged from four to seven, showing that appearance quality of rice grains were controlled by multigenes. The phenotypic variation explained by individual QTLs ranged from 6.