UNLOCKING RESILIENCE: GENETIC VARIABILITY AND TRAIT-BASED SELECTION FOR DROUGHT TOLERANCE IN F₃ PROGENIES OF RABI SORGHUM (SORGHUM BICOLOR (L.) MOENCH)

Abstract

Sorghum (Sorghum bicolor (L.) Moench) is a vital C₄ crop globally, with Rabi (post-rainy) sorghum in India facing significant yield instability due to post-flowering drought stress. This study aimed to assess the genetic variability, character association, and direct and indirect effects of yield component traits and drought tolerance parameters on grain yield in thirty Rabi sorghum genotypes, comprising twenty F₃ progenies, eight parents, and two checks. The experiment was conducted in a Randomized Block Design (RBD) at the Sorghum Research Station, V.N.M.K.V., Parbhani, during the Rabi 2022 season. Analysis of variance revealed highly significant differences among genotypes for all eighteen characters studied, indicating substantial genetic variability. High estimates of genotypic and phenotypic variance were observed for leaf area, flag leaf area, plant height, fodder yield per plant, grain yield per plant, and relative water content. High heritability coupled with high genetic advance as percent of mean was recorded for leaf area (94.60% heritability, 40.52% GA), flag leaf area (88.70% heritability, 39.38% GA), and grain yield per plant (76.80% heritability, 38.30% GA), suggesting the predominance of additive gene action and effectiveness of selection for these traits. Grain yield per plant exhibited a significant positive correlation with plant height, flag leaf area, relative water content, 1000 seed weight, and harvest index at both genotypic and phenotypic levels. Path analysis further revealed that plant height, flag leaf area, 1000 seed weight, and harvest index exerted the highest positive direct effects on grain yield. The superior F₃ progenies, including F₃-2-3 and F₃-1-4, demonstrated maximum grain yield (69.02 g/plant and 64.01 g/plant, respectively) and favorable drought tolerance traits. These findings suggest that selection based on these key morpho-physiological traits will be effective for developing high-yielding, drought-tolerant Rabi sorghum varieties.