IDENTIFICATION OF POTENTIAL PARENTS AND HYBRIDS IN INTRASPECIFIC CROSSES OF UPLAND COTTON

Combining ability analysis is an important tool for identifying superior parents suitable for both developing new cultivars and hybrids. Crosses were attempted in half diallel fashion involving five parental upland cotton cultivars. The mean squares due to general combining ability (GCA) and specific combining ability (SCA) were significant for four out of five characters studied. The significance of GCA and SCA variances anticipated that both additive and non-additive genes were controlling the traits. Yet GCA variances being higher than SCA variances exhibited more influence of additive genes on the traits. The parent Haridost expressed maximum GCA effects for plant height, sympodia per plant, while CRIS-134 for bolls per plant and seed cotton yield per plant. The GCA effects indicated that parent Haridost and CRIS-134 were the best parents to be used in crossing programme for the selection of desirable plants from segregating populations. The hybrids Shahbaz × Sindh-1 expressed greatest SCA effects for plant height, bolls per plant and seed cotton yield per plant, whereas Shahbaz × CRIS-134 gave maximum SCA effects for sympodia per plant thus suggesting that both the hybrids have the potential to be used for cotton hybrids development. The per se performance of some F1 hybrids was also reflected in their SCA effects suggesting their more reliability and potentiality for hybrid crop development.