Morphological Changes and Antioxidant Activity of <i>Stevia rebaudiana</i> under Water Stress

Abstract

Stevia rebaudiana , a herbaceous perennial shrub contains steviol glycosides, as an alternative source of sugar for diabetic patients. Water being an integral part plays a vital role in the maintenance of plant life. Availability of water is one of the limiting factors determining plant distribution and survival in natural ecosystem. The objective of this study was to investigate the ability of tolerance of Stevia plants to water stress. Potted plants of Stevia were subjected to different levels of water regimes (100 ml, 200 ml, 300 ml) per day, whereas control plants were watered daily with about 400 ml water. Plant height, leaf area, electrolyte leakage and antioxidant enzyme activity (peroxidase and catalase) were assayed during the experimental period. All these parameters were severely affected under water stress condition. Stress treatment caused an increase in electrolyte leakage compared to control. Plant height decreased under severe stress condition whereas a sharp increase in antioxidant enzyme activity was observed in stressed plants as compared to untreated control plants. Our experiment emphasizes the importance of proper watering schedule for the cultivation of Stevia as an agricultural crop to meet the challenges for sugar and energy crisis.