ABSTRACT

The present investigation was carried on genetic variability and diversity analysis among advanced breeding lines of rabi sorghum for charcoal rot tolerance and productivity traits. The experimental material consisting of 42 advanced breeding lines derived from nine crosses and eight check varieties was evaluated during rabi season 2023-24 at RARS, Vijayapur in RBD under three different experiments. High estimates of GCV, PCV, heritability (h2) and genetic advance over mean (GAM) were observed for traits grain and fodder yield per plant. Cluster analysis grouped genotypes into five clusters with cluster I being the largest. Among 10 traits, days to 50 per cent flowering contributed more towards total divergence. The highest inter cluster distance (554.76) was observed between clusters IV and V. Grain yield per plant recorded significant positive association with all the traits except panicle length and harvest index.
The charcoal rot tolerance traits, length of spread, number of nodes crossed by the pathogen and lodging percentage showed high PCV values. The genotypes were clustered into 15 groups with Cluster I being the largest group. Between clusters VI and XII, the highest inter-cluster distance (40.363) was observed. Stay green score was significantly and negatively correlated with SPAD at flowering, SPAD at maturity and hundred grain weight, and was significantly and positively associated with lodging percentage. Seventeen genotypes were showing moderately resistant disease reaction.
All the trait mean values in advanced breeding lines except for the traits plant height, panicle length and fodder yield per plant, were higher under medium soil when compared to deep soil condition. VJV 304, VJV 255, VJV 256, VJV 257, VJV 306, VJV 333, VJV 272, VJV 405, VJV 277-1, VJV 316, VJV 282, VJV 319, VJV 318, VJV 342, VJV 343 and VJV 411 were found promising for both charcoal rot and various yield traits.