Abstract:

Fertility inheritance in 4 populations of 2 parents (P₁ and P₂), F₁ and F₂ from each of the two crosses (BS210×BY149, BS210×O201) in wheat , were investigated by the mixed major gene plus poly-genes in genetic model of quantitative traits. The female parent BS210 is a photo-thermo sensitive male genic sterile line. The frequency distribution of fertility in F2 population of two crosses showed characteristics of a mixed normal distribution, which indicated that the inheritance of fertility followed a major gene plus poly-genes model. Twenty-four genetic models were established, which could be classified into five types: one major gene, two major genes, polygenes, one major gene plus polygenes and two major genes plus polygenes. Results showed the genetic model E-1 was the most suitable model for the trait, i.e. the fertility was controlled by two additive-dominance-epitasis major genes plus additive- dominance polygenes. The additive effects of two major genes were equal approximately with －10.626, －10.068 and －14.659, －14.655 in two crosses, respectively. The heritabilitis of major genes were 25% and 40% in two crosses, respectively. The additive effects of polygenes were －6.225 and 5.025, and the heritabilitis of polygenes were 16.67% and 13.33% in two crosses, respectively. Those indicated that the effects of major genes were identical approximately but the effects of poly-genes were great different possibly in the crosses with same female parent (photo-thermo sensitive male sterile line) and different male parents (restore lines). The effect of environment was significant to fertility. Therefore, the fertility was controlled by both of inheritable factor and environmental factor in this study.

Key words: Wheat, Photo-thermo sensitive male sterile, Fertility, Mixed major genes plus poly-gene genetic model