Quantitative-genetic analysis of reciprocal crosses between a winter and a spring cultivar of common wheat (Triticum aestivum L.)

The winter wheat cultivar Sakhalin (parent A) and the spring wheat cultivar Khush-hal (parent B), assumed to be both nuclear-genetically and plasmotypically different, were reciprocally crossed and the F₁ generation of the reciprocals backcrossed to either parent. The populations (AxB)F₁, (AxB)F₂, [(AxB)F₁xA]F₁ and [(AxB)F₁xB]F₁, and their reciprocals (BxA)F₁, (BxA)F₂, [(BxA)F₁xA]F₁ and [(BxA)F₁xB]F₁, assumed to have the plasmotypes of the parents A and B respectively, were spring sown in the same field from unvernalized (experiment #1) and vernalized (experiment #2) seeds. The results of the analyses of variance of the data recorded in the two experiments are fairly similar. In both the experiments the plasmotypically A populations have produced more heads and higher grain yields per plant than their plasmotypically B reciprocals. The components of the family means and of half the differences between the reciprocals within the families show that vernalization has not affected the efficiency of the nuclear genes of parent A but has reduced the efficiency of the nuclear genes of parent B in both the homozygous and the heterozygous states. This in turn has affected the components of family mean squares and those of the family x reciprocals interaction mean squares in the analysis of variance tables.