Studies on Genetic Divergence in Forage Sorghum [Sorghum bicolor (L.) Moench]

Abstract

The present investigation was conducted in forage sorghum adopting 32 diverse genotypes with randomized block design during Kharif 2006. Attempt were made to (I) Examine the extent to genetic variability components, (II)workout the nature of association, (III) Direct and indirect effects of different characters of green fodder yield, and (IV) Genetic divergence among 32 forage sorghum genotypes of different geographical origin. Observations were recorded for days to 50% flowering, days to milking stage, plant height (em), nodes per plant, internode length (em), stem girth (em), leaf breadth (em), leaf length (em), leaves per plant, leaf stem ratio, total soluble solids (%), protein content(%), green fodder yield per day (q/ha/day), and green fodder yield (qlha). Analysis of variance revealed substantial amount of variability for various characters namely: leaf stem ratio, stem girth, total soluble solids, leaf breadth, green fodder yield per day, nodes per plant, leaves per plant, internode length and plant height may be useful for further developing high yielding forage sorghum varieties. Genotypic correlations were of higher magnitude as compared to their corresponding phenotypic correlations in most of the character combinations. Green fodder yield was found to be positive and significantly correlated with green fodder yield per day, days to 50% flowering, days to milking stage, leaf length, nodes per plant and plant height. Thus, any selection based on these characters will enhance performance and improvement in forage sorghum. Path coefficient analysis showed that green fodder yield per day, days to milking stage and days to 50% flowering were the most important characters, controlling directly to green fodder yield. Mahalanobis 0 2 statistics revealed considerable genetic diversity among the genotypes. The genotypes grouped into 7 clusters. The I and II cluster having the maximum number of genotypes. This envisaged that the genotypes grouped within a particular cluster are more or less genetically similar to each other and apparent wide diversity is mainly due to the remaigneniontyp~eg di stributed over rest of the other clusters.