Genetic and cytological evaluation of diallel crosses among eight bread wheat genotypes [electronic resource].

Includes references.

The present investigation was carried out to throw some light on the cytological disturbances e. g. frequency of micronuclei and chromosomal aberrations as an indication of the cytological instability and to study the genetic system controlling the inheritance of some agronomic characters using half diallel analysis of eight genetically diverse wheat genotypes. The studied parents exhibited variation frequencies of mitotic activity the highest score was in P₃, P₆ and P₈ and the lowest in P₄, P₅ and P₇ The parental genotypes showed also differences in micronuclei and chromosomal aberration, the highest score was in P₂ and P₇ and the zero score in P₃ and P₈ most of F₁ hybrids showed less micronuclei and chromosomal aberrations in mitotic division than their parents. However some hybrids had higher percentage of cells containing either micronuclei or chromosomal aberrations than their parents. The additive genetic variance (D) was significant for all studied traits. indicating that additive gene effects played a major role in the inheritance of these traits. Dominance component of variation (HI) was highly significant and greater than (D), for all traits. The component of variation due to the dominance effects associated with gene distribution (H2) was highly significant and greater than D for all traits. Average degree of dominance (H1/D)¹/², showed the presence of over dominance for all studied traits. except number of spikes/plant and 1000 kernel weight which exhibited complete dominance. Low heritability estimate in narrow sense was detected for all traits except heading date, number of spikes/plant and 1000 kernel weight which showed high estimate.

Summary in Arabic.

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