Özet:

The estimation of gene effects in the inheritance of yield components is one of the most important tasks in wheat breeding programs. The objective of this study was to estimate gene effects for the number of grains and grain weight per spike in ten wheat crosses with five basic generations: parent cultivars (P1, P2), first and second filial generations (F1, F2) and first backcrosses (BC1). The gene effects responsible for inheritance of these two important traits were estimated on the basis of generation mean analysis, using an additive-dominant model with three and six-parameters. The adequacy of the additive-dominance model with three-parameters was tested using the Scaling test and Chi-square (χ2) test. A three-parameter model was found as adequate to explain variation for the both traits in three crossing combinations. The magnitude of additive gene effects (d) was smaller than the corresponding dominance effects (h) in most crosses for both traits. The application of six-parameter models indicated the significant epistatic effects for explaining genetic variation for these traits. The inheritance of these traits was influenced by additive×additive (i) and dominance×dominance (l) type of non-allelic interactions in the study. Duplicate gene interactions were also observed in most crosses of both characters which are difficult to exploit in breeding programs. These results implied that the selection for the improvement of these traits should be applied in further generations in wheat breeding..

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