COMBINING ABILITY IN SOME BARLEY GENOTYPES UNDER RAINFED AND IRRIGATION CONDITIONS

doi:10.12816/ejpb.2019.256682

COMBINING ABILITY IN SOME BARLEY GENOTYPES UNDER RAINFED AND IRRIGATION CONDITIONS

Document Type : Original research

10.12816/ejpb.2019.256682

Abstract

Two field experiments were conducted at Maryout Agricultural Research Station of Desert Research Center, North Western Coast, Egypt under irrigated and rainfed conditions. Six wheat genotypes were used to evaluate half diallel cross (15 F₁hybrids) during the two winter seasons 2015/16 and 2016/17. Mean squares due to the genotypes (parents and their F₁'s) and irrigation treatments were significant, indicating that the presence of wide diversity among genotypes and the highly differences between the two regimes for all traits under study. Positive and significant heterotic effects were found for most crosses for plant height, grain yield/plant and its components under irrigation and rainfed treatments except for the two crosses P₄×P₆ and P₅×P₆. Mean squares due to both GCA and SCA were highly significant or significant for all the studied traits under irrigated and rainfed conditions. Detection of high GCA/SCA ratios (that exceeded unity) for most studied traits indicated that the largest part of the total genetic variability for these traits was the result of additive and additive×additive gene action types. The superiority of three parents (P₂, P₃ and P₅) was identified and these parents appeared to be good general combiners for improving most studied traits. Hybrid combinations of these parents might have desirable transgressive segregations, providing that the additive genetic system present in different crosses for increasing grain yield/plant and its components under the two water regimes. For SCA, the desirable inter-and intra-allelic interactions were presented in six crosses combinations (P₁×P₃, P₂×P₃, P₂×P₄, P₃×P₅, P₃×P₆ and P₄×P₅), which showed desirable significant specific combining ability under both irrigation treatments. These crosses might be of interest in barley breeding programs to produce higher yielding lines with tolerance to environmental stresses, since most of them involve at least one good parental combiner for the trait of interest under irrigated and rainfed conditions.

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