Character Association Studies of Sugar Yield and its Component Traits in Rainfed Sweet Sorghum

The character association study was undertaken in four large F2 populations of sweet sorghum under rainfed condition. Four newfangled, intervarietal crosses were generated by crossing three elite grain sorghum genotypes viz., 27 B, ICSB 38 and 296 B as a female parent and four sweet sorghum genotypes viz., SSV 84, SSV 74, URJA and NSSV 13 as a male parent during kharif 2010 and second filial generation in the following season. Correlation studies revealed significant and positive association of sugar yield with juice yield, fresh stalk yield, total biomass, grain yield, total soluble sugars, brix per cent, bioethanol yield and juice extraction per cent. Some of these correlated traits were in turn used to construct the selection indices by employing discriminant function analysis. The selection index comprising of six character combinations viz., sugar yield, total biomass, fresh stalk yield, brix percent, juice yield and total soluble sugars was more effective with higher relative efficiency. While, selection based on five characters combinations viz., sugar yield, total biomass, fresh stalk yield, brix per cent and juice yield as well as four character combinations viz., total biomass, fresh stalk yield, brix per cent and juice yield were also equally effective in selecting the plants for maximum sugar yield. However selection index comprising six and five character combinations embracing derived parameters such as sugar yield and total soluble sugar were of little importance in selection process. In this regard it is advisable to go for four characters combination which also manifested maximum relative efficiency coupled with higher genetic advance.