Abstract:
Bread wheat variety development plays vital role in enhancing productivity and product quality in Ethiopia, which could be achieved by the information generated from the pre-breeding activity. To achieve this, the study aimed to assess genetic variability, heritability, genetic advance, correlation and path analysis among 49 bread wheat genotypes for 17 quantitative traits. The experiment was conducted at Dabat and Debark research stations of Gondar Agricultural Research Center during the main cropping season of 2022, using a 7 x 7 simple lattice design. The genotypes showed significant variation for most traits, both within and across locations, according to the analysis of variance. The average grain yield of the genotypes varied from 2.3 to 4.37 ton/ha in the two locations. The combined analysis showed that the genotypic coefficient of variation (GCV) ranged from 0.77% for days to maturity to 18.33% for thousand-kernel weight. The phenotypic coefficient of variation (PCV) ranged from 2.41% for starch content to 29.85% for grain yield. The broad-sense heritability (H2b ) ranged from 4.81% for the number of spiklets spike-1 to 89.47% for starch content. The genetic advance as a percentage of mean (GAM) ranged from 0.36% for days to maturity to 23.37% for thousand kernel weight in the combined locations. Grain yield had positive and highly significant genotypic and phenotypic correlations (p≤0.01) with harvest index, hectoliter weight, starch content, thousand kernel weight, number of kernels spike-1, days to maturity, grain filling period and number of spiklets spike-1. The genotypic path analysis showed that grain filling period had the highest positive direct effect on grain yield (0.975), followed by biomass yield (0.373). At the phenotypic level, harvest index had the highest positive direct effect on grain yield (0.787), followed by grain protein content (0.610). The cluster analysis divided the 49 genotypes into five clusters, with cluster III having the highest intra-cluster distance (D2=4.73). The largest inter-cluster distance was between cluster III and V (D2=17.91). Principal components (PCs) with Eigen values >1 explained 79.00% of total variation among genotypes. This research showed the existence of genetic variations among bread wheat genotypes for yield, indicating the potential use in future breeding programs.