Changes in plant water status, biochemical attributes and seed quality of black gram and green gram genotypes under drought

Drought is one of the major abiotic stresses which adversely affect crop growth and production worldwide as water is vital for every aspect of plant growth and development. The present investigation was carried out during the growing seasons (September - December) of 2012 and 2013 to evaluate the response of black gram (Vigna mungo L.) and green gram (Vigna radiata L.) genotypes in terms of some important growth indices, biochemical traits and seed quality under drought stress. Four commonly grown genotypes-T9, KU 301(black gram) and Pratap, SG 21-5 (green gram) of Assam, India were grown in a randomized block design with three replications under stress and non-stress conditions. Stress was applied by withholding irrigation for fifteen consecutive days at vegetative, flowering and pod filling stages. Leaf area index (LAI), seed protein content and protein yield significantly decreased (p <= 0.01) whereas proline, total flavonoids and anthocyanin content increased significantly (p <= 0.01) in response to water deficiency. Among the studied genotypes, T9 and Pratap showed better tolerance capacity towards the applied drought by presenting higher values of LAI, plant height stress tolerance index (PHSI), dry matter stress tolerance index (DMSI), proline, total flavonoids, anthocyanin, lower percentage of chlorophyll degradation and finally producing high quality seeds.