Analysis on combining ability and heritability of major agronomic characters in hybrid rice parents.

The combining ability and heritability of 8 major agronomic characters of 10 rice parents and their F1heterosis were determined by the NCⅡ mating design.The results showed that there was significant difference in general combining ability(GCA) and specific combining ability(SCA) of 8 agronomic characters between 10 rice parents,the heredity of plant height(PH),panicle length(PL),effective panicles/plant(EPP),total grains/panicle(TGP),filled grains/panicle(FGP),seed setting rate(SSR) and 1000-grain weight(TGW) mainly depended on additive effect and the heredity of grain weight/plant(GWP) mainly depended on non-additive effect,the heterosis of combination was affected simultaneously by general combining ability(GCA) and special combining ability(SCA),there was a significant positive correlation between parent GCA and its competitive heterosis,and the narrow heritability of 8 agronomic characters plant heightgrains/paniclepanicle length1 000-grain weighteffective panicles per plantfilled grains per panicleseed setting rategrain weight per plant.