Abstract: Five hybrid rice sterile cytoplasms commonly used in production and five restorer lines with high combining ability were used in this experiment. Using NCII model, the parental combining ability, contribution rate of variance and heritability of major agronomic traits including yield traits, awn and grain shape were analyzed. The results showed that the effects of cytoplasm and restorer in the measured traits were in significant or highly significant differences levels, while the environment impact on awn length, grain shape and single ear weight were less. The non-additive genetic effects of yield and harvest index was obvious, also influenced by environmental effects. In the parental effect, the effect of restorer is much stronger than that of cytoplasm; In yield traits, the general combining ability of JW cytoplasm and Shuhui 527 is high, while JW cytoplasm and R21 belong to the class I parents; In gain shape trait, the general combining ability of G cytoplasm and Shuhui527 is high, both of them also belong to the class I parents.

Key words: hybrid rice, cytoplasmic effect, combining ability, heritability