INDUCED GENETIC VARIABILITY, HERITABILITY AND TRAIT ASSOCIATIONS IN YELLOW-PERICARP SORGHUM [SORGHUM BICOLOR (L.) MOENCH] MUTANTS
Abstract
Yellow-pericarp sorghum possesses nutritional and industrial value owing to its carotenoid content, low condensed-tannin concentration and high starch recovery. However, such landraces in peninsular India remain largely unimproved with limited genetic diversity available for conventional breeding. The present study explored genetic variability and trait associations in 60 M4 derived mutant lines from the yellow-pericarp sorghum landrace “Udgir Piwali” through gamma irradiation (100–500 Gy), ethyl methanesulphonate (EMS; 0.1–0.3%) and their combined treatments. Sixty-four entries, including three released checks and the parental control were evaluated for 19 morphological, yield and physiological traits in a randomized block design with two replications during post rainy season of 2024–25 at Parbhani, Maharashtra, India. Analysis of variance revealed significant differences among entries for all traits, with the greatest variation observed for fodder yield and panicle-related traits. Phenotypic coefficients of variation exceeded genotypic coefficients for all traits. Panicle weight and fodder yield showed high heritability (80 and 88%, respectively) coupled with high genetic advance as per cent of mean (37.72 and 37.27%), indicating substantial scope for selection. Grain yield per plant exhibited moderate heritability (55%) and genetic advance (15.59%). Genotypic correlation analysis showed strong positive associations of grain yield with panicle length (rg = 0.910), panicle weight (0.855), panicle width (0.687) and stem diameter (0.592). Path analysis identified positive direct effects of internodal length, panicle length and days to maturity, whereas flag leaf area and plant height exhibited negative direct effects. The study identified 400Gy 2, 400Gy-4, 500Gy-3, 300Gy-5 and 0.2% EMS-4 as promising mutant lines for further evaluation. These lines may serve as useful genetic resources for improving productivity in yellow-pericarp sorghum.