Assessing genetic variability in sorghum bicolor for biomass and biofuel-related traits: A comprehensive estimation

The energy crisis is giving rise to long term social and economic issues as they both are closely related. The production of biofuel from plant-based biomass is becoming an attractive alternative to non-renewable energy sources. Sorghum is a model bioenergy crop owing to its high biomass yield and low input requirements. In the present study, 142 accessions of Sorghum bicolor were evaluated for biomass (plant height (cm), stem thickness (mm), no. of leaves/plant, leaf area (cm2), intermodal length (cm), green fodder yield (g)) and biofuel (moisture contents (%), protein contents (%), acid detergent fiber (ADF), neutral detergent fiber (NDF), ash contents (%), crude fat (%) and hemicellulose content (%)) related traits, selected accessions were crossed in line × tester mating design, seven lines and five testers were selected and resultant F1 progeny along with their parents were evaluated and data were recorded to estimate genetic variability, additive and dominance variance, combing ability effects, and gene action among the traits. Highly significant differences were found among all the accessions, parents, parents vs crosses, crosses, lines and testers. Line × tester was also found significant for all the biomass traits and biofuel related traits except moisture content and ash content. Genetic variability indicated that this material can be used for the development of improved genotypes for biomass and biofuel related traits. Results of general combining ability estimates indicated that lines L1, tester T5 were the best general combiners for biomass traits and L6, L7, testers T1, T2 for biofuel related traits. Whereas specific combining ability estimates indicated that crosses L1 × T3, L1 × T5, L2 × T2, L3 × T5, L7 × T3 were the best specific combiners for biomass and L2 × T2, L4 × T5, L5 × T1 for biofuel. Partial dominance was observed for most of the traits. Based on association studies, plant height, green fodder yield, neutral detergent fiber, and hemicelluloses might be used as selection criteria for improved biomass and biofuel related traits in sorghum breeding. (author)