Combining ability and heterosis on millable stalk and sugar concentration for bioethanol production across environments in sweet sorghum (Sorghum bicolor (L.) Moench.).

Combining ability studies involving five females, six males and 30 hybrids respectively at three semi-arid locations by following a line x tester mating design. Five top ranking hybrids selected for the present investigation revealed the presence of significant differences due to liens, testers and lines x testers x environment effects for all traits suggesting the environmental influence on tester and the interactions. The estimates of variance components exhibited presence of additive gene action for total soluble solids and non-additive for fresh stalk yield, juice yield, bio ethanol yield and grain yield. Among female NSS 1016 A was highly efficient and productive line for all characters, best general combiner for these traits. Female NSS 8 A for grain yield and PMS 71 A for fresh stalk yield, total soluble solids and grain yield indicate that the best general combiner for these traits. Tester SSV-74 was potential male parent with high significant GCA effect for all traits and RSSV-138-1 was best general combiner for fresh stalk yield, juice yield and bio ethanol yield. The top ranking five hybrids viz., NSS 1016 A x RSSV-138-1 for fresh stalk yield and total soluble solids, Juice yield and bio ethanol yield, NSS 8 A x RSSV-138-1 for juice yield, Ethanol yield and fresh stalk yield. PMS-71 x RSSV-138-1 for total soluble solids, NSS 1016 A x UK-81 for bio ethanol yield and total soluble solids, NSS 1016 A x SSV-74 for grain yield after testing across many locations, these hybrids recommended for commercial exploitation for bio-ethanol production of the semi-arid target environments in India.