Morphologgical Changes and Antioxidant Activity of Stevia rebaudiana under Salt Stress

Stevia rebaudiana, a herbaceous perennial shrub contains steviol glycosides, as an alternative source of sugar for diabetic patients. Salinity is one of the limiting factors determining plant distribution and survival in natural ecosystem. The objective of this study was to investigate morphological changes and antioxidant activity of Stevia rebaudiana under salt stress and the ability of tolerance of Stevia plants to salt stress. Plants of Stevia were subjected to different levels of salt (1.58, 2.58, 5.2, 6.60, 10.17 and 13.7 EC mmhos/cm), whereas control plants were watered with tap water. Plant height (cm), plant spread (NS--EW), leaves number per plant, stem numbers/plant, stem fresh weight (g), leaves fresh weight (g), stem dry weight (g), leaves dry weight (g) and antioxidant enzyme activity (peroxidase) were assayed during the different cutting time. All these parameters were found to be severely affected under salt condition. Salt treatment caused an increase in electrolyte leakage compared to control. There is an increase in antioxidant enzyme activity under the high level of salt compared to untreated control plants. The experiment emphasizes that variety of stevia which used under this study can planting in the salt soil until 5.20 EC salt as an agricultural crop to meet the challenges for sugar and energy crisis.