The assessment of gene action in 10 × 10 half-diallel crosses in bread wheat (Triticum aestivum L.) was this study’s focus, carried out during 2023–2024 at the Kirkuk Governorate, Iraq. The experiment based on the said breeding material had a randomized complete block design layout with three replications. The genetic analysis revealed that the t2 values were nonsignificant for all traits, and the additive genetic variance (D) was significant for all studied traits. Dominant gene variations (H1 and H2) were higher than the additive gene variance for all traits, with H1 values exceeding H2. The average degree of dominance was greater than one, indicating a predominance of dominant gene action. The ratio of dominant to recessive alleles (KD/RR) exceeded one, reflecting unequal distribution of alleles among the genetic structures.
Bread wheat (T. aestivum L.), gene action, genetic parameters, additive and dominance genetic variances, average degree of dominance
In the bread wheat (T. aestivum L.), the genetic analysis revealed that t2 values were not significant for most traits, except spike count. The dominance genetic variances were higher than the additive genetic variance for all traits, indicating a greater influence of dominant genes.