Estimation of Heterosis for Yield and Yield Attributing Traits in Diallel Crosses of Upland Cotton (Gossypium hirsutum L.)

Diallel analysis was carried out by involving nine parents and their seventy two cross combinations in upland cotton to identify the best heterotic crosses for seed cotton yield and its attributing traits. Analysis of variance showed highly significant differences due to genotypes for all the traits indicating the presence of sufficient variability in the experimental materials. Variance due to parents and hybrids showed significant differences between all the characters studied except number of bolls, boll weight, single plant yield, lint index and seed index. Significance of variance in parents versus hybrids interaction provides adequacy for comparing the heterotic expression for all the characters except boll weight, ginning percent, lint index and seed index. Heterosis was worked out over mid parent, better parent and standard check variety. Based on study of relative heterosis and heterobeltiosis, it was found that number of sympodia per plant, number of bolls per plant and boll weight were main contributors towards increase in heterotic effects for single plant yield. Three crosses viz., MCU 5 x MCU 7 (27.40%), KC 2 xMCU 5 (22.18%) and Anjali x MCU 5 (20.72%) were best heterotic crosses over standard check for single plant yield and could be exploited.