Comparative analysis of phytochemicals, antioxidative defense mechanism, and yield responses of Vigna radiata L. cultivars HUM 1 and HUM 16 under salinity stress

Abstract

Salinity stress is posing serious threat to global food production and accountable for 20–50% of yield loss in various crops via hampering morphological, biochemical, and physiological processes of plants. To evaluate the impact of 0-, 50-, and 100-mM salinity levels, a pot experiment was conducted under ambient conditions on mung bean cultivars (HUM 1 and HUM 16). Reduction in plant height was observed by 15.1% and 34.8% for HUM 1 and 7.3% and 27.5% for HUM 16 under 50 and 100 mM, respectively. Higher generation of superoxide radical (51.3%) and hydrogen peroxide (29.1%) was observed for HUM 1 under 100 mM resulting into higher membrane damage (51.0%), assessed in the form of MDA content. To counter this oxidative stress, significant induction in non-enzymatic and enzymatic antioxidants like ascorbic acid (11.2% and 28.9%), superoxide dismutase (29.9% and 48.0%), and catalase (25.4% and 60.9%) was observed for HUM 1 and HUM 16 under 100 mM, respectively. On the other hand, significant accumulation of phenols and flavonoids was also noticed for HUM 16 under 50 and 100 mM. Reduction in yield was recorded more for HUM 1 (33.6% and 46.9%) as compared to HUM 16 (15.8% and 41.4%) under 50 and 100 mM, respectively. Results of the present study clearly demonstrated that 100-mM salinity stress was more severe as compared to 50 mM, and the magnitude of impact was observed higher for HUM 1 as compared to HUM 16.