Genetic Analysis of Yield and Yield Related Traits in Sorghum (Sorghum bicolor L.) Through Line × Tester Design

The present investigation was conducted across three diverse locations, RARS, Nandyal; ARS, Podalakur; and RARS, Lam, Guntur. Two lines and eight testers were crossed following a Line × Tester design during rabi 2021–22 and rabi 2022–23 to generate sixteen hybrids. These hybrids, along with their ten parents, were evaluated during summer 2022 (Nandyal), rabi 2022-23 (three locations) and summer 2023 (three locations) to assess genetic variability and the nature and magnitude of gene action for yield, yield components and physiological traits. Analysis of variance revealed significant genotypic differences for most traits across environments, indicating substantial genetic variability. Moderate phenotypic and genotypic coefficients of variation were observed for grain yield (PCV up to 19.25%; GCV up to 17.97%) and dry fodder yield, while days to flowering and maturity showed low variability. High heritability was recorded for grain yield (92% in pooled analysis) and 100-grain weight (90%), coupled with high genetic advance as per cent of mean for grain yield (27.69%), indicating the predominance of additive gene action and strong response to selection. Physiological traits such as relative water content, per cent membrane damage and specific leaf area also exhibited high heritability, highlighting their genetic stability under stress conditions. Overall, the study identified grain yield, plant height, relative water content, membrane damage and specific leaf area as reliable selection criteria for enhancing sorghum productivity and drought tolerance across diverse environments.