Genetic analysis of narrow-sense heritability and genetic advance as percent of mean for seed cotton yield and its component traits in upland cotton (Gossypium hirsutum L.)

The present investigation aimed to estimate narrow sense heritability and expected genetic advance for key agronomic and fiber traits in cotton to assess their potential for genetic improvement through selection. The results revealed moderate to high heritability accompanied by high genetic advance for traits such as days to flowering in Crosses I and IV, plant height in Cross IV, number of monopodia in Crosses I, III, and IV, number of sympodia in Cross IV, boll weight in Cross III, and seed index, indicating that these traits are primarily governed by additive gene action. Consequently, direct phenotypic selection in early segregating generations would be effective for improving these characters. In contrast, traits such as days to boll opening, number of bolls per plant, overall seed cotton yield (except in Cross III), lint index, fiber strength, and fiber uniformity showed high to low heritability but low genetic advance, suggesting the predominance of non-additive gene effects or significant environmental influence. These findings emphasize the need for alternative breeding strategies, such as recurrent selection, heterosis breeding, or multi-environment trials, for improving complex traits less responsive to direct selection.