Evaluation and prospects of F₂ genotypes of cotton (Gossypium n hirsutum) for yield and yield components

The heterosis is a tool to increase cotton (G. hirsutum L.) yield but due to difficulties in producing F₁ seed, the use of heterosis in cotton has been limited. The objective of this study was to evaluate the potential F₂ hybrids by comparing them with parents, commercial varieties and F_1s for yield, yield components and fiber quality. The genetic design was half diallel, consisting five parents (CIM-496, MNH-554, FH-901, FH-945, LRA5166, 10 F₁ & 10 F₂). The differences among genotypes were determined. The highest yielding parent was CIM-496 3521kg ha^-1 followed by MNH-554 with 3268 kg ha^-1. While the variety FH-901 with 2391 kg ha^-1 yielded minimum among the parents. With cross combinations MNH-786 × VH-144, MNH-554 × LRA-5166, and CDVI-499 × LRA - 5166 showed minimum inbreeding depression i.e., -39.72, -27.85 and -22.72 for seed cotton yield, yield components and fiber traits than expected inbreeding depression i.e., 50.0%. General combing ability mean squares were significant for all traits and specific combing ability mean squares were also significant for all traits, ability (GCA) and specific combining ability (SCA) mean squares were significant, while the GCA effects were higher than SCA effects for all traits. This showed that additive gene action is prevailing with dominant gene action for expression of these traits. The variety FH-901 was the best general combiner for the yield and yield components. It is concluded that F₂ can be used for availing the heterosis after evaluating the proper cross combination; parents and the cost of seed production will also be reduced.