Genetic analysis of spike yield components in winter wheat.

Parent selection with desirable traits and making crosses among them is an important procedure for increased production. The knowledge of genetic association between grain yield and its components would improve the efficiency of breeding programs by identifying appropriate indices for selecting wheat varieties. Diallel analysis is most effective with proven merits for ascertaining the systematic genetic architecture of metric traits within a short period. In diallel technique, analysis of variance components are of considerable use in gathering precise picture of genetic architecture. The objective of this study was to obtain information on nature of gene action and magnitude of contribution to various characters like spike yield and its components in 7×7 diallel crosses. For both traits there is an asymmetry of the positive and negative alleles showing a degree of dominance in the studied varieties. The partial dominance was involved in the determinism of these traits. In case of grain number, at GKHattyu and Ati varieties the high proportion of recessive alleles were associated with positive effects, while for Romulus and Lovrin 34 varieties, the dominance causes an increase of grain number. At Lovrin 34 variety the dominant alleles are associated with higher values of grains weight while in GKHattyu variety the recessive allele causes an increase of spike yield.