Effect of Selenium on physiological and biochemical indexes of Vitis vinifera cv. Cabernet Sauvignon leaves under water stress

Abstract：The effect of Selenium on physiological and biochemical indexes of Cabernet Sauvignon under water stress was investigated to provide reference for drought tolerance cultivation of grape. The Vitis vinifera L. cv. Cabernet Sauvignon cuttings cultivated for one year were sprayed with Se-fertilizer under water stress at the Na2SeO3 concentrations of 0, 0.5, 1.0, 1.5 mg· L-1. Grape leaves were sampled at spe-cial stage after Se-fertilizer spray to detect the content of chlorophyll, soluble sugar, proline and MDA as well as the enzyme activity of SOD,POD,CAT and GSH-Px. During the whole period of water stress, compared to CK the chlorophyll content was increased by 2.93% to 8.43% and soluble sugar content was increased by 9.7% to 14.2% in average after treatment, and the proline content was increased by 12.0% to 61.6%. While the SOD and POD activity was enhanced by 1.5% to 6.6% and 46.2% to 87.8%, respectively, and the CAT and GSH-Px activity was increased by 18.5% to 22.6% and 14.5% to 34.9%, correspondingly, but the MDA content was decreased by 14.5% to 34.9%. Under this experimental condition, the effect of drought tolerance with 1.0 rag·L^-1 （T2） treatment was the best for Vitis vinifera L. cv. Cabernet Sauvignon. Results indicated that under water stress, appropriate concentration of sodium selenite solution can relieve chlorophyll decomposition in grape leaves and increase soluble sugar and proline con-tent, and also regulate the enzyme activity of SOD, POD, CAT and GSH-Px, make the MDA content decrease. The application of Se could improve the capability of cellular antioxidant defenses to enhance the drought tolerance.