The Genetic Laws Of Light And Temperature Sensitive Male Sterile Wheat And Heterosis

Based on the discovery of photoperiod-temperature sensitive male-sterility in wheat, China scientists have been developing two-line hybrid wheat to secure the future food safety during the recent years. Since the photoperiod-temperature sensitive male-sterility of wheat is a typical ecological phenomenon, it is controlled not only by male sterile genes but also by ecological conditions such as photo-period and temperature. The well-understanding of the genetic mechanism of photoperiod-temperature sensitive male sterility of wheat will help enhance the breeding efficiency of two-line hybrid wheat. And the heterosis in wheat can be fully exploited in the future.The genetic mechanism of photoperiod-temperature sensitive male-sterile wheat was studied in our research among populations derived from single segregating generation and multiple generations by means of mixed inheritance model put forward by Gai jun-yi, zhang yuan-ming and Wang jian-kang. In addition, the heterosis and combining ability of 46 two line wheat hybrids were analyzed .The main results are as follow:1. The results of joint analysis of multiple generations of P₁, P₂,F₁, F2 of the crosses BS366×BAIYU149 and BS366×CR149 showed that the seed setting rate in cross BS366×BAIYU149 was controlled by two major genes with additive-dominance-epistatic effects and polygenes with additive-dominance-epistatic effects, and in cross BS366×CR149 was controlled by two major genes with additive-dominance-epistatic effects and polygenes with additive-dominance effects. In the total genetic effect of BS366×BAIYU149 cross, epistatic effect was higher than dominance effect and dominance effect was higher than additive effect. The major gene heritability was 34.67%, and the polygene heritability was 25.20%. Environment affect on seed setting rate is high, its' variance was 40.30% in the phenotype variance. In the total genetic effect of BS366×CR149 cross, epistatic effect was higher than dominance effect and dominance effect was higher than additive effect. The major gene heritability and polygene heritability were 64.17% and 14.76% respectively, which showed major genes played major role in seed setting rate. Environment effect on seed setting rate was relatively low, and its' variance was 20.83% in phenotype variance .2. The analysis results of F₂ populations of the crosses BS20×BAIYU149 and BS20×86E22 showed that the seed setting rate in both crosses was controlled by two major...