SELECTING HIGH YIELDING WHEAT HYBRIDS FROM A RESTRICTED FACTORIAL MATING DESIGN

Seven bread wheat (Triticum aestivum L.) genotypes (G1-6, G1-118, Adnania used as males while IPA 95, Abu Graib, Fatih and B-35 used as females) were assessed for yield and yield associated traits using factorial mating. The seven parents and their 12 F1 progenies were planted in randomized complete block design with three replications, Duhok University, Kurdistan Region-Iraq, during the growing season 2010 – 2011. Highly significant differences (p 0.01) among the genotypes were observed for plant height, leaf area, days to flowering, number of grains spik^-1, number of spikes plant^-1, weight of 1000 grain and grain yield plant^-1. The male parent G1-118 and the female parent B-35 had a positive general combining ability effect for most of the traits including grain yield, while the hybrid G1-6 × Abu Graib had positive specific ability for most of the studied characters except days to flowering. The additive genetic variance was more than dominance genetic variance for most of the studied traits. Narrow sense heritability was high for plant height, days to flowering, number of spike plant^-1, 1000- grain weight, and grain yield plant^-1. Expected genetic advance as percent was observed higher for plant height, leaf area, number of spikes plant^-1, weight of 1000-grains, and grain yield plant^-1. Most of the hybrids displayed significant positive heterosis for 1000-grain weight, grain spike^-1, days to flowering, flag leaf area and plant height, and the hybrids G1-118 × IPA 95, and G1 -118 x B-35 manifested positive heterosis for flag leaf area, grain spike^-1,spike plant-1 1000-grain weight, and grain yield.