Y. Madhumitha1* and P. Senthil Kumar2
Abstract
Estimation of combining ability and magnitude of heterosis was conducted at the Department of Genetics and Plant Breeding Farm, Faculty of Agriculture, Annamalai University, in a set of 10 parents (seven lines and three testers) by making 21 cross combinations evaluated during February 2022 to April 2022 in RBD with three replications. The data on eight characters viz., days to fifty per cent flowering (days), plant height (cm), number of branches per plant, number of fruits per plant (g), fruit length (cm), fruit girth, single fruit weight (g), yield per plant were utilized for the present study. The GCA/SCA variance ratio was less than one for all the traits studied, suggesting the predominance of dominance (non-additive) gene action governing the traits. The estimates of combining ability variances revealed that SCA variance was highly significant than the GCA variance as observed from the GCA/SCA ratios for all the traits studied which indicated the preponderance of non-additive gene action. The mean squares due to gca, sca effects were significant for fruit yield and yield contributing traits studied. None of the parents identified as good general combiner for fruit yield per plant but the parents Arka Anamika, Pusa A4, IC 045993, IC 058704 and IC 049972 were identified as average general combiners for yield per plant. Estimated heterosis showed that cross âIC 049972 x Arka Anamikaâ had the higher Relative heterosis and Heterobeltiosis in total fruit yield also IC 058704 x Arka Anamika had higher relative heterosis in the same trait. Among twenty-one hybrid combinations, three crosses viz., IC 058704 x Arka Anamika, IC 049972 x Arka Anamika and IC 045993 x Pusa â A4, should be exploited for further advancement in breeding programme.