Exploiting combining ability and heterosis for yield and fiber quality improvement in cotton (Gossypium barbadense L.)

The present investigation in Gossypium barbadense L. using a full diallel mating design involving six diverse genotypes revealed substantial genetic variability in agronomic and fiber quality traits. Additive gene action predominated for ginning percentage, fiber length, and fiber strength, whereas seed cotton yield and days to first flowering were mainly governed by non-additive gene action with significant reciprocal effects. Parents RACT 3790 and RACT 5293 were superior general combiners for yield, whereas RACT 3844, RACT 5293, and RACT 5296 were valuable donors for fiber quality improvement. Hybrids RACT 3844 × RACT 5293, RACT 5293 × RACT 5296, and RACT 3790 × RACT 5296 were identified as promising combinations for yield improvement, whereas RACT 3959 × RACT 5294 was superior for fiber quality traits. These results provide valuable information for identification of parental lines and hybrid combinations for exploiting both the additive and non-additive gene actions for developing high-yielding cotton cultivars with improved fiber quality.