Combining ability analysis in intraspecific F1 diallel cross of upland cotton (Gossypium hirsutum L.)

Abstract

Diallel analysis was carried out by involving nine parents and their 72 cross combinations in upland cotton for assessing their combining ability for yield and its component characters. 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 per cent, lint index and seed index. The GCA variances were larger than those of SCA for all the traits except number of bolls per plant, indicating the preponderance of additive action. The parents MCU 5 and MCU 7 were proved to be good general combiners for single plant yield and other economic traits and hence need to be included in the yield improvement programmes. The hybrid combinations viz., MCU 5 x MCU 7, Khandwa 2 x Suraj, KC 2 x MCU 5, Anjali x MCU 7 and Anjali x Suraj recorded superior per se performance for number of bolls, boll weight and single plant yield and other characters. Among these crosses KC 2 x MCU 5, Anjali x Suraj and Anjali x MCU 7 exhibited additive type gene action with one good general combining ability parent for number of bolls, boll weight and lint index respectively. Hence, selection can be made in these crosses in early generation itself.