Morpho-physiological Criteria for Drought Tolerance in Sorghum (Sorghum bicolor) at Seedling and Post-anthesis Stages

Ten sorghum genotypes including one check (JS-2002) were evaluated at seedling and post-athesis stages for drought tolerance based on morpho-physiological criteria. The data regarding all morpho-physiological traits such as dry root weight, root length, coleoptile length, root: shoot ratio, flag leaf area, specific flag leaf area, specific flag leaf weight, leaf dry matter, excised leaf weight loss, relative dry weigh, relative water content, residual transpiration, cell membrane stability and grain yield per plant revealed significant (P>0.01) differences among the genotypes. Blocking considerably affected specific flag leaf area, specific flag leaf weight, leaf dry matter, relative water content and cell membrane stability. The genotypes H-18 followed by PGRI-191, PGRI-35 and PARC-SS-1 showed better stress tolerance traits. Genotypic coefficient of variation was the highest for excised leaf weight loss followed by grain yield suggesting considerable scope for selection of these traits. High estimates of broad sense heritability and genetic advance for all the characters indicated the most appropriate condition for selection against these traits except for relative dry weight. Correlation analysis revealed that root length, coleoptile length, root: shoot ratio, flag leaf area, leaf dry matter, excised leaf weight loss, residual transpiration cell membrane stability and grain yield might be improved simultaneously and could be exploited as reliable morpho-physiological markers for drought tolerance in sorghum at seedling and reproductive stages.