Electronic Journal of Plant Breeding

An investigation was carried out to assess the combining ability and nature of gene action in respect of juice yield and its attributing traits in 72 new hybrids of sweet sorghum developed by crossing 4 male sterile lines with 18 testers in Line x Tester mating design and grown in Randomized Block Design with two replications during kharif 2008. The variance among the lines in respect of their general combining ability was highly significant for days to 50 per cent flowering, nodes per plant and juice yield, where as variance among testers was significant for juice yield. The variance due to line x tester interaction was significant for all the characters indicating differential response of lines with different testers. SCA variance was relatively higher in magnitude for all the traits indicating predominance of non-additive gene action in the genetic control of these traits. ICSA 38 and ICSA 102 among the lines and ICSV 93046, E 36-1, ICSV 700, SEREDO and GD 65008 among the testers, were identified as good general combiners indicating their ability in transmitting additive genes in the desirable direction to their progenies. Highly significant sca effects were observed in most of the hybrids for all the characters studied and good specific combiners for different characters involved parents with high x high, high x low, low x high and low x low general combinations.