INHERITANCE OF STRIPE RUST AND SOME RELATED CHARACTERS IN BREAD WHEAT

Abstract

The results of yellow rust indicated that the additive, dominance, and the three epistatic effects (aa, ad and dd) were important in the inheritance of stripe rust disease. The genetic variance was more pronmmced than the environmental one. The estimates value of heritability in broad sense were high in the five crosses. The narrow sense heritability estimates were high in all crosses except in cross No. 5 which was intennediate indicating the importance of the additive genetic effects in the inheritance of yellow mst disease resistant in bread wheat. Average degree of dominance indicated partial dominance in the crosses No. 1 and 3 for yellow rust disease resistant in bread wheat and over-dominance in the cross No. 5.

The results of agronomic traits indicated the existence of gene interactions and the importance of both additive and non-additive types of gene effects in the inheritance of most studied traits. The estimates of heritability values in broad sense were high in most traits. While, the narrow sense heritability values were moderate to low for the most traits. The results revealed that selection for early genotypes in early generations would be effective for the most studied traits.

The phenotypic and genoty pic cotTelation coefficients between stripe rust reaction and each of spike kemels weight, 100 kernel weight, and grain yield I plant showed a highly significant and negative values in most crosses tmder study.

The phenotypic and . genotypic correlation coefficients between most agronomic traits were significant and positive in most cases.