Genetic and genotype × environment interaction effects from embryo, endosperm, cytoplasm and maternal plant for rice grain shape traits of indica rice

Abstract

A seed genetic model with embryo, endosperm, cytoplasmic and maternal effects and genotype×environment (GE) interaction effects was used for analyzing ratio of length-to-width (RLW) and ratio of length-to-thickness (RLT) of indica rice ( Oryza sativa L.). A factorial mating design in two environments was conducted by including nine cytoplasmic male sterile lines (A) and five restorer lines (R) along with their F 1 (A×R), F 2, reciprocal RF 2 and BC 1 (A×F 1). RLW and RLT were found to be controlled mainly by genetic main effects, but also by GE interaction effects. Variance of maternal effects was larger than other variance components. Variance due to embryo effects and embryo×environment interaction effects could also significantly affect the rice grain shape traits. The total narrow-sense heritability for RLW and RLT were about 85.6 and 69.9%, respectively, with the general heritabilities being 62.5 and 61.9% and the interaction heritabilities being 23.1 and 7.9%. It was suggested by the predicted genetic effects that Zhexie 2, Xieqingzao and Cezao 2-2 were better than other parents for improving rice grain shape traits.