COMBINING ABILITY AND HETEROSIS STUDIES IN FORAGE SORGHUM (SORGHUM BICOLOR (L.) MOENCH) ACROSS ENVIRONMENTS

Abstract

Combining ability analysis through a line X tester set for 9 forage characters in four environments and on pooled basis revealed the importance of both additive and nonadditive gene actions. However, the ratio of c:rgea/c:r sea showed greater importance of nonadditive gene action. The parental genotypes 2077A, 36A and M·31·2A among females and Vidisha, IS 4776, IS 644, Rio, IS 3287 and IS 685 among males showed the highest gca effects, whereas the crosses 2077A x Vidisha, M·31·2A x IS 3353, 2219A x IS 4776 M-31·2A XRio, 2219 A x IS 3287, and CK GOA x IS 4776 among hybrids exhibited the highest and significant sca effects for yield and its components. While gca was stable for fodder yield and number of yield components, sca was highly unstable for all the characters across the environments. Highly significant but varying degrees of heterosis was observed for the characters under study.