The study variation of phytochemical and antioxidant activity of Stevia rebaudiana Bertoni. irrigated with magnetized saline water (Golestan province)

Stevia rebaudiana Bertoni. is one of the valuable medicinal plants, in which extremely used in pharmaceutical and nutritional industries as a sources of non-calories sugar. The present experiment was carried out investigation of phytochemical variation, resistance to salinity and increasing the saline water usage efficiency using magnetic field. Experiment was evaluate by using four levels of salinity (0, 2, 4 and 6ds/m2) and three levels of magnetic fields (0, 3000 and 6000 G) as treatment in three replications. In September 2015 the leaves of Stevia rebaudiana Bertoni. Were collected from the research field of Gorgan University of Agricultural Sciences and Natural Resources. The total phenol content was measured by folin ciocalteu method, flavonoid content with aluminum chloride, antioxidant activity by DPPH methode and the total and reduced sugar content were measured by using Fehling methods. Results were showed that the salinity had significant influence on total phenol and flavonoid contents at 1% probability and by increasing the level of salinity the content of these compounds were decreased. The salinity did not have statistically significant effect on the other parameters like antioxidant activity, total sugar and reduced sugar. Although no significant effect of magnetic water was observed on these parameters, but the interaction effect of salinity and magnetic field on the antioxidant activity of extract and total sugar was significant. So according to present study, the stevia is sensitive to salinity of pre-treatments water with magnetic field in this case is not effective.