Estimation of Genetic Parameters and Character Associations, and Disease Resistance of Bread Wheat (Triticum aestivum L.) Genotypes

Abstract

The experiment was conducted during July–November in 2023 main cropping season at Kulumsa Agricultural Research Center  to assess the extent of genetic variability and the association among traits in bread wheat genotypes. Analysis of variance revealed significant genetic variation (p<0.01) among genotypes for seven of the nine studied characters. Grain yield exhibited the widest range, varying from 891(EBW232651) to 1682.5 (EBW232625) kg ha-1, with an average of 1325.96 kg ha-1. Encouragingly, 78% of studied genotypes exhibited superior grain yield compared to check Balcha (1242.5 kg ha-1). A moderate range of PCV and GCV were obtained for agronomic score, grain yield and thousand kernel weight, offer the most significant potential for improvement through selection. The high broad-sense heritability observed for days to heading days to maturity, hectoliter weight and thousand kernel weight, and traits with high GAM viz. grain yield and agronomic score, suggested a significant role of additive gene action in controlling these traits. Grain yield exhibited strong positive and highly significant correlations (p<0.01) at both genotypic (rg) and phenotypic (rp) levels with Agronomic Score, Thousand kernel weight and hectoliter weight. Grain yield displayed a strong negative and highly significant correlation (p<0.01) at both genotypic and phenotypic levels with yellow rust severity. The negative correlation with yellow rust severity emphasized the need to prioritize resistance breeding to protect yield potential from this disease. This finding suggested that selecting for improved agronomic score, hectoliter weight, and thousand kernel weight could be effective indirect selection strategies for enhancing grain yield in this breeding population.