Genetics of Yield and Other Traits in American Cotton

A half diallel set among 10 parents of hirsutum cotton was undertaken to evaluate combining ability and its interactions with environments. The experiment was conducted under three environments in a randomized block design, replicated thrice. ANOVA showed highly significant differences for all the traits studied. All characters except four, i.e., monopodia per plant, seeds per boll, seed index and fiber fineness were influenced by the environments. Variance ratio revealed the preponderance of non-additive genetic variance. Significant general combining ability (gca) and specific combining ability (sca) x environment interactions were observed for most of the characters. The best general combiners in all the environments were: C-2602-WIR-6109 for monopodia per plant and seed cotton yield, LH 1861 for bolls per plant and RS 2115 for seeds per boll. Crosses exhibiting highest sca effects coupled with high per se performance were LH 1836 x H 1123 for plant height, bolls per plant, seed index and seed cotton yield; and PIL 8-5 x RS 2115 for plant height and seeds per boll