Study of combining ability and gene action for forage yield and its component characters in forage sorghum [ Sorghum bicolor (L.) Moench]

Six grain type CMS sorghum genotypes (females) were crossed with seven fodder type sorghum genotypes (males) in a line x tester mating design. A perusal of variance ratio Iƒ2gca/ Iƒ2sca suggested the preponderance of non-additive genetic variance for all the characters except plant height at 50% flowering, leaf width, dry matter content and hydrocyanic acid content. Looking to the parents for characterization of their ability to transmit desirable genes to their progenies, females SURAT 5, AKMS 14A and 3660 A and males SSG 59-3, GAFS 11 and AFS 48 were found good general combiners for green fodder yield plant-1 and its component traits like plant height at 50% flowering, number of leaves plant-1, leaf length, leaf: stem ratio and dry matter content. Out of 42 hybrids evaluated, 7 hybrids registered significant positive sca effects for green fodder yield plant-1, of these, the best three cross combinations were AKMS 14A x AFS 53, 3660 A x SSG 59-3 and SURAT 4 x GAFS 11.