The Effect of Foliar Application of Selenium on Physiological and Biochemical Characteristics of Rosemary under Drought Stress

In order to investigate the effect of selenium foliar application on the physiological and biochemical characteristics of rosemary under irrigation treatments, a factorial experiment was conducted in a completely randomized design in the greenhouse of University of Zabol, Agricultural Research Institute in 2018. The first factor was two levels of irrigation (80% and 30% of field capacity) and the second factor was four levels of selenium foliar application (0, 50, 75 and 100 mg/l). The results showed that foliar application of selenium increased the RWC, carotenoid, protein and ascorbate peroxidase under stress conditions, and the highest amount of these traits were obtained at 75 and 100 mg/l selenium. Foliar application of selenium especially at 75 mg/l under stress conditions increased the soluble carbohydrate, total phenol, guaiacol peroxidase enzyme, polyphenol oxidase enzyme and essential oil percent. The content of ion leakage, proline and catalase increased with stress and the contents of chlorophyll a, b and total decreased. The content of chlorophyll a, b and total, proline and catalase enzymes were increased by foliar application of selenium, especially at 75 mg/l and ion leakage was reduced by selenium foliar application, especially at 75 and 100 mg/l. In general, selenium application by increasing antioxidant compounds (phenol, flavonoid and antioxidant enzymes), osmotic regulators (proline and soluble carbohydrates) and photosynthetic pigments, and reducing ion leakage, alleviation drought stress in rosemary.