Combining ability of parents and hybrids for sugar yield and its attributing traits in sweet sorghum [Sorghum bicolor (L.) Moench]

Abstract

An investigation was carried out to assess the combining ability and nature of gene action in respect of sugar yield and its attributing traits in 25 new hybrids of sweet sorghum developed by crossing five (5) high-sugar lines with five (5) low-sugar lines in a North Carolina II mating design and grown in alpha lattice with two replications during long rains season of 2014 in western Kenya. The variance among the lines in respect of their general combining ability was highly significant for brix and plant height at 90 days. Specific combining ability variance was relatively higher in magnitude for grain weight and plant height indicating predominance of non-additive gene action in the genetic control of these traits. GADAM, MALON and PAISANO among the females and IESV93046, IS2331 and NTJ 2 among males were identified as good general combiners indicating their ability in transmitting additive genes in the desirable direction to their progenies. The best hybrids for total biomass and total sugar content were GADAM × IESV93046, GADAM × IS2331 and MALON × IS2331, and after adequate testing in many locations across the target production environments these hybrids can be recommended for commercial exploitation for ethanol production.