Combining ability and heterosis study for yield and it’s attributing traits in maize (Zea Mays L.)

Abstract

Combining ability and heterosis was studied in maize for grain yield and its attributing traits using line x tester mating design. Significant general and specific combining ability variances were observed for all the characters
studied indicating the importance of both additive and non-additive gene action for the expression of these traits. Among the parents GPM-4, GPM-38, GPM-608, GPM-688, GPM-759, GPM-648 and CI-4 were found to be good general combiners for days to 50% tasseling and days to 50% silking. Similarly, GPM-18, GPM-27, GPM-30 and GPM-606 were good combiners for grain yield. Among the test hybrids GH-1834 and GH-1813 were found to be promising recording significant SCA effects for Number of kernels/ row, cob length and cob girth. whereas, for 100 seed weight GH-1852 and GH-1819 and for grain yield GH-1862, GH-1843,GH-1852 and GH-1829 were found to be promising. Similarly, among the 64 F1 hybrids significant economic heterosis of 21.0 and 6.46 per cent over National and Popular private hybrid check was recorded by both the test hybrids GH-1809 and GH-1829 respectively. GGE biplot technique was used to understand the interrelationship between genotypes, testers and their interaction and it could explain the variation through two components PC1 (55.28 %) and PC2 (44.72 %). The parental line L5 (GPM-27) which falls on the ATC absicca showed the highest GCA effects for grain yield followed by L7  (GPM-30). Likewise, among the two testers CM-111 was able to discriminate more number of genotypes.