Genetic variability and multivariate analysis of quantitative traits in advanced crosses and accessions of cotton (Gossypium hirsutum) in Ethiopia

Exploration of the magnitude and pattern of heritable variation within plant genetic resources is a prerequisite for maximizing the efficiency of selection and strategic integration in breeding programs. In this study, genetic variability and the interrelationships among quantitative traits were assessed in cotton crosses and strategically important accessions with potential tolerance to abiotic stresses and adaptation to sustainable agricultural practices. The design used was a 7 × 7 partially balanced simple lattice design replicated twice. The results revealed significant variability in the boll number per plant, boll weight, seed cotton yield, ginning out-turn, and lint yield implying they harbor useful genetic diversity that could be essential for both current and future cotton breeding progress. In addition, some genotypes showed considerable advantages over the current popular varieties for seed cotton yield (6.59% to 22.60%) and lint yield (8.37% to 20.47%). These results highlight the potential of the evaluated genotypes to enhance economically important traits. High heritability (≥ 83.58%-87.2%) and genetic advance as percentage of the mean (20.04%-25.74%) were observed for plant height, seed cotton yield, and lint yield, indicating additive gene action, which offers a higher response to selection. The correlation analysis revealed positive and significant correlations between boll number per plant, boll weight, seed cotton yield and lint yield which could allow indirect selection and improve breeding efficiency. The first two principal components explained most (75.61%) of the total variability implying grouping and selection of divergent genotypes could be effective relying on key traits represented by the same components. In conclusion, the substantial genetic variability observed across all the examined traits highlights the considerable potential of the studied plant materials for further evaluation across diverse agro-ecologies.