Genetic analysis for protein content in indica rice

Analysis of genetic main effects and GE interaction effects for protein content (PC) and protein index (PI) of indica rice (Oryza sativa L.) was conducted for two year experimental data by using a genetic model for quantitative traits of seeds in cereal crops. Nine cytoplasmic male sterile lines or maintainers as female parents and five restorer lines as male parents were used for a NC II mating design in 1995 and 1996. The results indicated that PC and PI traits were simultaneously controlled by genetic main effects as well as GE interaction effects. For PC and PI of rice, the embryo interaction effects (embryo additive and dominance interaction effects) were important as effects of triploid endosperm, cytoplasm and diploid maternal plant. The estimates of narrow-sense heritability for PC and PI of rice were 85.3% and 77.9%, respectively. The interaction heritability was found to be larger than the general heritability for PC and PI of rice. Significant relationships for components of different genetic effects between PC and PI were found. The GE interaction covariances tended to be positive.