Combining ability and heterosis for fodder yield, quality and its component traits in forage sorghum [Sorghum bicolor (L.) Moench]

The aim of this study was to estimate the general combining ability (GCA) of the parents and specific combining ability (SCA) of hybrids considered for the development of high yielding and better quality cultivars of forage sorghum. Nineteen parents and 60 F1 hybrids obtained by crossing 4 male sterile lines and 16 fertile lines in line x tester matting system during Kharif 2012 were sown in randomized block design in three replication during summer and Kharif 2013 with two different date of sowing. Analysis of variance revealed significant differences among genotypes, parents and hybrids for all the traits on pooled basis. Combining ability analysis revealed presence of both additive and non-additive gene effects. The SCA variance was found to be more important to gca variance for green and dry fodder yield per plant, plant height, stem diameter, leaf width, leaf: stem ratio, shoot fly dead heart percentage, quality characters and days to flowering, which favored a hybrid breeding programme. The female parents 9A and 14A were found to be good general combiners for most of the characters under study. Among male parents, SRF 327 and SPV 2113 were found as good general combiners for fodder yield per plant, yield attributes and quality related traits. Out of 60 hybrids, 24 hybrids showed significant positive sca effects on pooled basis for green and dry fodder yield per plant. The best five hybrids based on significant positive sca effects for green fodder yield per plant were 104A x SPV 1616, 27A x SPV 1616, 9A x SRF 331, 14A x SRF 335 and 27A x SRF 317. These cross combinations involved poor x poor, good x poor, poor x average, good x poor and good x good GCA effects, respectively. Out of these five hybrids, 27A x SRF 317 and 14A x SRF 335 had high per se performance with significant positive heterosis and positive sca effects for fodder yield, its contributing traits and quality traits.