Exploring genetic variability for morphological and yield contributing traits in sorghum (Sorghum bicolor (L.) Moench) germplasm from Southern India

Abstract Sorghum is a major cereal crop grown worldwide for its grain, livestock feed and biofuel. In order to characterize the pattern of genetic diversity in the germplasm and advanced mutant lines, the present study was undertaken to evaluate 103 genotypes for 11 agro-morphological traits over two post rainy seasons in 2019 and 2020. Significant variation for quantitative traits was observed with a wide range of coefficients of variation (4.85–26.04%). A broad range of trait values was recorded for grain yield (13.0—152.6 g/plant), seed index (1.0–5.5 g/100 seeds), panicle length (9.2–31.4 cm) and panicle width (3.2–15.0 cm). The genotypic and phenotypic coefficient of variation were found high for panicle length, panicle weight, seed weight and grain yield. A broad sense heritability estimated in this population ranged from 0.79 to 0.99. Among the significant phenotypic correlations, grain yield was strongly correlated with leaf width, stem diameter, panicle width and weight. In addition, traits such as stem diameter, panicle weight, panicle width, number of leaves and leaf length showed significantly positive correlations with all other traits. Multivariate methods used in this study identified key traits associated with grain yield and grouped all the genotypes into six major clusters, clearly distinguishing germplasm and mutant derivatives. Among the genotypes studied, IC-288363 and EP-1 germplasm, and M-35–48 mutant exhibited high grain yield and more seed weight. Germplasm and mutant lines demonstrated wide variability for most of the quantitative traits and can be utilised for developing new cultivars or used as parents in the recombination breeding.