Genetic Analysis of Heterosis for Number of Spikelets per Panicle and Panicle Length of F1 Hybrids in japonica Rice Hybrids

Genetic analysis of heterosis for number of spikelets per panicle and panicle length of F1 hybrid was conducted by using japonica rice varieties Bing 8979, C Bao, their F1, F2 and triple test cross (TTC) progenies. The two traits, panicle length and number of spikelets per panicle were controlled by polygenes, which were dispersed in the two parents. The dispersion of these polygenes was the genetic basis for the heterosis. Genetic variation in panicle length was mainly due to additive and dominant effects, and the dominant component played a determinative role. For number of spikelets per panicle, the effect of non-allelic genes was highly significant (1% probability level), and there existed epistasis including effects of additive×additive, additive×dominant, and dominant ×dominant.