[Studies on fertility genes and its genetic characters in D2-type CMS lines of common wheat]

The kinds of fertility genes and its genetic characters for D2-type CMS lines of common wheat were studied, the results showed: (1) For D2-type CMS line, there was wide restoring sources and high digree of restoration in common wheat varieties (the restoring degree of 33.61% varieties exceeded 50%), and new CMS lines were easily bred (25.21% varieties could maintain male sterility). These characters indicated that D2-type CMS line was higher value in applied study, compared with T, K, V-type CMS lines. (2) There were two forms of nuclear genotype for D2-type CMS lines, namely A1(sterile gene) and A2(sterile gene + inhibiting gene). In nucleus of restorer lines, the fertility genotype was conditioned by 6 forms: C1(major restorer gene), C2(major restorer gene + minor restorer gene), C3(minor restorer gene), C4(major restorer gene + inhibiting gene), C5(major restorer gene + minor restorer gene + inhibiting gene), C6(minor restorer gene + inhibiting gene). The genetic expression of fertility genes was affected by environmental factors. The basic model of effective combination was A1 + C1, A1 + C2, A2 + C2. (3) The allelic restorer-genes were characterized by incomplete dominance and the nonallelic restorer-genes were characterized by additive effect, which was the important basis of breeding good restorer lines.