| Abstract: | The genetic study of characters concerning photoperiod sensitivity of the growth and development stages, plant and ear height was carried out from 5 temperate tropical combinations by using P1, P2, F1,F2, BC1, BC2 generations mean analysis. The results showed that the square sums of additive, of dominance and of epistatic gene effects contributed to total genetic variance were 11.3 -53.6 %, 36.0 -78.6 % and 5.5 -27.0% respectively for five traits of the insensitive× insensitive combination to photoperiod, which suggested dominance gene effect was the most important among various gene effects. In insensitive × sensitive combination to photoperiod, the square sums of additive gene effect with 66.9 - 84.5 %, of dominance gene effect with 11.6 -30.7% and of epistatic gene effect with 1.4 -5.2% were found for five tested traits, which showed additive gene effect held a dominant position, and dominance and epistatic gene effects were reduced compared with insensitive× insensitive combination. The differences existed among different insensitive × sensitive combinations. The proportion of the genetic component among the insensitive × sensitive crossbreed offspring in the temperate zone had a certain dosage effect on fading photoperiod sensitivity reaction. The sensitivity of BC1, with 25 % of the tropical genetic component, is extremely weak, but with high application value. |
