Genetic Effects Assessment through Line × Tester Combining Ability for Development of Promising Hybrids Based on Quantitative Traits in Gossypium hirsutum L.

Abstract

Line × Tester combining ability analysis involving five lines (cultivars i.e., CIM-446, CIM-473, CIM-506, CIM-554 and SLH-284) and three testers (cultivars viz., CIM-496, CIM-499 and CIM-707) was carried out during 2015 and 2016 to determine the inheritance for earliness, yield and lint traits in upland cotton. Genotypes revealed significant (P≤0.01) variations for all the traits. On average, F1 hybrids showed the significant increase over parental means for yield traits. Mean squares due to general (GCA) and specific combining ability (SCA) were highly significant, which suggested that additive and non-additive gene actions were involved in controlling all the characters. However, the preponderance of non-additive type of gene action observed for majority of the traits. Lines (SLH-284, CIM-473) and pollinators (CIM-707, CIM-496) were leading general combiners for majority of the traits. F1 hybrids (CIM-473 × CIM-496, SLH-284 × CIM-707 and CIM446 × CIM-496) which involve best general combiners, showed the leading performance for yield and lint traits. Heritability was moderate to high with appreciable genetic gain for majority of the traits. Except for lint %, the correlation of seed cotton yield was positive with other traits. The significance of additive and non-additive components suggested integrated breeding strategies with delayed selection for development of cotton hybrids with improvement in earliness and seed cotton yield.