Mapping of QTLs Controlling Grain Plumpness of Rice Using Doubled Haploid Lines

Composite interval mapping was conducted to map both main-effect and digenic epista-(tic) loci for grain plumpness using a doubled haploid population derived from a indica/japonica cross.One main-effect QTL (qGP-7) for the trait was located onto a 26 cM chromosomal region marked by RZ978RG404aRG404c on chromosome 7.This QTL explained 10%-15% of the phenotypic variation.Two pairs of interactions were identified,each accounting for about 20% of the phenotypic variation,suggesting the importance of epistasis as genetic factor of the trait.