Analysis of combining Abilities and Gene effects for grain Yield and related traits in Durum wheat, (Triticum durum Desf.)

Abstract

This study included implementation of a half diallel crosses among ten genotypes of durum wheat in 2020-2021. The next growing season 2021-2022, first generation and the parents have been planted at the Agricultural Research Station of Koya/ Erbil by using Randomized complete block design (RCBD) with three replications. The grain yield trait and its components were studied. General combining ability (G.C.A.) and specific combining ability (S.C.A.) and gene effects were estimated. The results revealed that parent (9) had desirable and high G.C.A. effects for all traits except of plant-height, while the cross (8×10) showed desirable S.C.A. effects for all traits. The additive variance (σ²A) was higher than dominant (σ²D) for the plant-height and number of grains/ spike. And the dominant variance was higher for the rest traits. High values of heritability in both broad sense (H²_b.s.) and narrow sense (H²_n.s.) were recorded for plant-height and number of grains/ spike. Average degree of dominance was greater than one for flag-leaf area, number of spikes/plant, 1000 grain weight and grain yield/plant. Whereas, moderate expected genetic advance was found for number of grains/spike and grain yield/plant.