Vol. 12, Issue 11 (2023)

Author(s):
Revanasiddayya, SS Patil, Ayyanna, Manjula SM, Rakshith P, P Kariyannanavar and SB Patil

Abstract:
A study on combining ability status guides a breeder to choose elite combiners and crosses that can be released as commercial hybrids. The present study was conducted at the Botanical Garden, Department of Genetics and Plant Breeding, UAS, Dharwad during Kharif 2018-19 in a randomized complete block design with two replications. The main objective of the study was to assess the combining ability status of six parental lines and thirty cross combinations developed based on naked seeded types using the full diallel method in American cotton. Combining ability effects were estimated for important yield-related traits, viz., seed cotton yield per hectare (kg/ha), number of bolls per plant, and boll weight (g). Simple analysis of variance revealed significant differences among the parents, hybrids, and their reciprocals for all three traits studied. All three traits were found to be under the control of non-additive gene action, as revealed by the higher magnitude of SCA variance. Based on the gca effects of parents, it is revealed that DHN-3 proved to be the best general combiner due to the highest seed cotton yield and the production of the maximum number of bolls and boll weight. Based on sca effects, the specific cross DHN-1 × DHPN-2 performed better for seed cotton yield. Some unique combinations, such as DHN-1 × DHPN-2, DHN-3 × DHPN-1, DHN-2 × DHPN-1, and DHN-2 × DHPN-2, were identified as the best for the number of bolls per plant, while the crosses DHN-1 × DHPN-2, DHN-2 × DHPN-1, DHN-2 × DHPN-2, and DHPN-2 × DHN-1 were found to be the best for boll weight. It can be concluded that the expression of traits can be improved by employing heterosis breeding, as traits were inherited in a non-additive manner.