| 【Objective】The combining ability and heritability of four premium backbone sterility lines and five main
restorer lines in agronomic characters of hybrid rice were analyzed.【Method】Four backbone sterile lines and five backbone
restorer lines in common production were selected for incomplete diallel cross, and the yield and grain shape traits of the
offspring were analyzed statistically to dissect the combining ability and heritability.【Result】The results indicate that the
narrow-sense heritability of yield of hybrid rice was less than 50% and there was great difference between it and the broadsense heritability. The yield was greatly affected by non-additive effect and easily affected by environmental factors. The
spikelets panicle and effective panicle had significant effects on yield. The GCA effect value of yield of Yixiang 1A was 8.02,
and the GCA effect value of spikelet panicle was 1.47. The yield GCA effect value of Xikehui 4761 was 8.37 and the GCA
effect value of effective panicle was 8.74. The grain shape was greatly affected by additive effect, and the effect of restorer
lines was greater than that of sterile lines. The variance contribution rates of parents of restorer lines with length-width and
grain length were 89.68% and 63.75%, and the variance contribution rate of parents of sterile lines and restorer lines to grainwidth both were 40.68%. Combinations with larger grain length and length-width ratio had longer grain shapes.【Conclusion】
The parents with high general heritability in grain length and length-width ratio, especially for restorers, should be selected for
long grain shape hybrid combinations. The parents with high heritability in number of grain spikelets and effective spike number
should be selected to increase yield. “Yahui 2115”, a Class I parent on rice grain shape was obtained in the study, which
could be used to match a combination of large and full grain shape. A large and plump combination of Yixiang 1A/Yahui 2115
and a high-yield hybrid combination Yixiang 1A/ Shuhui 498 were verified. |
