Six-parameter genetic analysis of yield and fibre quality traits in upland cotton (Gossypium hirsutum L.)

Abstract

Cotton (Gossypium hirsutum L.) is a major commercial crop and an important source of natural fibre, making the understanding of its genetic architecture essential for crop improvement. The present study employed generation mean analysis using six generations (P₁, P₂, F₁, F₂, BC₁ and BC₂) to investigate the nature of gene action governing yield-contributing and fibre quality traits. Significant scaling tests and chi-square (X2) values for several traits indicated the presence of epistatic gene interactions. The analysis revealed that both additive and non-additive gene effects contributed to trait inheritance, with duplicate epistasis predominating for several economically important traits. These findings suggest that the inheritance of yield and fibre quality traits is complex, involving multiple gene interactions. Therefore, breeding strategies that exploit both additive and non-additive genetic variation, including selection in advanced generations and population improvement approaches, are likely to be more effective for developing superior cotton genotypes.