Assessment of combining ability and genetic parameters for yield and fiber traits in upland cotton (Gossypium hirsutum L.) using Line × Tester analysis

Seed cotton yield and fiber quality are two critical parameters that fundamentally define the economic and industrial value of cotton. The present work focused on improving cotton genotypes both for yield and quality parameters through intraspecific crosses. Estimation of combining ability parameters for forty-five Gossypium hirsutum genotypes employed the Line × Tester mating design. Significant (p≤0.01) differences in mean squares values were observed across all studied traits for the genotypes. Regarding parental lines, P2-103 and P1-190 demonstrated the highest positive general combining ability (gca) effects for seed cotton yield per plant, boll weight, and number of bolls per plant, thereby being identified as exceptional combiners. From the comprehensive set of forty-five crosses, P1-62×Suraksha and P2-36×Subiksha emerged with notable positive specific combining ability (sca) effects across multiple traits. Non-additive genetic variance (σ²D) predominantly exceeded additive genetic variance (σ²A) for most traits, suggesting potential exploitation of superior cross combinations through heterosis breeding strategies.