Biochemical changes in black gram and green gram genotypes after imposition of drought stress

To evaluate the response of drought stress on some important biochemical traits, fourblack gram (T9, KU 301) and green gram (Pratap, SG 21-5) genotypes were grown in the experimental field of Tezpur University, Assam, India in a factorial randomized block design with three replications. Drought was imposedat three different growth stages namely vegetative, early reproductive and pod filling stages and various biochemical parameters were recorded. Leaf water potential, total chlorophyll, starch and the activity of nitrate reductase were found to be positively correlated with seed yieldwhile negative correlation was obtained with total soluble sugar content. Leaf water potential, total soluble sugars and nitrate reductase activity have been identified as marker trait for selecting drought tolerant genotypes of black gram and green gram. From the analysis of variance (ANOVA), it has been observed that genotypic variability, treatment effect and the interaction between treatment and genotype was significant for all the studied traits (p ≤ 0.05). Early reproductive stage has been identified as the most vulnerable stage of growth with regard to drought. T9 (black gram) and Pratap (green gram) were found to be more tolerant against the applied drought.