Concurrent Improvement of Stem Sugar, Stover and Grain Yield in Sudanese and Exotic Sorghums II: Heritability, Genetic Advance and Association Studies

Aims: To investigate heritability, genetic advance from selection and the possibility of combining high levels of stem sugar with grain and stover yields in one cultivar.

Methodology: Twenty eight exotic and local sorghum (Sorghum bicolor (L.) Moench) genotypes arranged in Alpha lattice design were evaluated for stem juice, grain and stover yields and related traits.

Results: Apart from brix and extractability, genotype and environment (G x E) interaction was highly significant for all traits curtailing differences among genotypes and resulting in extremely low values for heritability and related genetic parameters. Analysis of variance performed in each season revealed highly significant differences among genotypes for all traits with medium to high heritability values coupled with high genetic advance from selection. Millable cane yield, stover yield, grain yield/plant, extractability and juice yield are expected to respond better to selection during summer while brix respond better during winter. All of the stem juice traits attributing to sugar yield other than brix were positively associated with grain and stover yield. Brix and grain yield showed weak negative correlation. Plant height and days to flowering showed favorable or at least trouble-free associations with the major productive traits.

Conclusion: The results suggest the importance of seasonal impacts when selecting for traits attributing to stem juice, grain and stover traits. The association study suggests the possibility of incorporating high levels of stem sugars, grain and stover yield in one cultivar.