EFFECT OF DROUGHT STRESS ON THE PHYSIOLOGICAL AND BIOCHEMICAL CHANGES IN Vigna radiata

A study was undertaken to examine the different level of drought stress under different stages of growth on the basis of physiological and biochemical traits. Sterilized seeds of Vigna radiata (T-44 and PDM-139) were inoculated with specific Rhizobium consortium and allowed to grow and then 7 days old seedlings were exposed to drought stress i.e. DS I and DS II and allowed to grow under natural environmental conditions. At 15 and 21 days stage, plants were harvested to evaluate various morpho-physio and biochemical parameters. The results clearly indicated that growth bio-markers decreased in response to drought stress whereas, accumulation of proline and activities of various antioxidant enzymes increased most prominently in T-44 at later stage of growth. It is concluded that drought stress (DS I) destruct the physiological functions and biochemical metabolism of Vigna radiata by decreasing photosynthetic efficiency and altered antioxidant system. However, deteriorating effect of drought stress was more effective in PDM-139 over T-44 at early stage of plant growth. At later stage, it believed that increased accumulation of proline and enhanced antioxidant system provide tolerance against drought stress.