Genetic diversity for earliness, fibre quality and yield components in cotton (Gossypium spp)

Abstract

Cotton is one of the most important source of natural fibre in the World. The crop is also an essential source of vegetable oil and animal feed. Genetic improvement of important agronomic traits including fibre yield and quality has been slow due to its narrow genetic base, and this necessitate the need to study and explore on the germplasm resources with the aim to identify and select novel lines which can be used as parents in hybridization programmes. One hundred cotton genotypes were evaluated from diverse sources in a 10 x 10 lattice design, replicated twice across two environments in 2022 wet season. Significant (p<0.01) genotypic variation was observed for plant height, number of sympodial branches, number of bolls, seed cotton yield and the degree of pest attack. The phenotypic coefficients of variations were higher than the corresponding genotypic coefficients of variations for the entire traits studied. Highest genotypic and phenotypic coefficients of variations were recorded by seed cotton yield (18.2  and 36.5), number of sympodial branches (34.0 and 34.3) and number of bolls per plant (27.5 and 30.5). Genotypes VIR-7112-HG-69-15, VIR-7072, LA-213-SEA-ISLAND LEAF, BULGARIA-996 and 30858 with rank summation indices of 243, 270, 313, 330, 332 and 368 respectively, were the best potential parents for hybridization when targeting genetic improvement while LINIA-7010 with rank summation index of 712 was the least promising. It could be concluded that significant genetic variation exists for important agronomic and fibre quality traits like seed cotton yield, number of bolls, plant height, number of sympodial branches, fibre length and fibre fineness and selection based on the aforementioned could make genetic improvement feasible.