Alleviation of Salinity Effect on Almond by Foliar Spray of Hydrogen Sulfide

Salinity is one of the most important abiotic stresses that severely affect the yield and quality of plants. The use of hydrogen sulfide in low concentrations increases tolerance to various stresses, including salinity in plants. This study aimed to investigate the effect of hydrogen sulfide (H2S) on reducing the damage to almond rootstock under salinity stress. The experiment was performed as a factorial based on a completely randomized design with four replications. The treatments included four levels of salinity (0, 30, 60 and 90 mM NaCl) and four concentrations of H2S (0, 0.05, 0.10 and 0.15 mM). Results showed that salinity stress, especially at a concentration of 90 mM NaCl caused a significant decrease in stem height, relative chlorophyll and leaf relative water content and a significant increase in injury rating value, electrolyte leakage, proline and sodium concentrations of root and shoot, activities of catalase and peroxidase of leaf. However, H2S at concentrations of 0.10 and 0.15 mM improved plant growth with a decrease in electrolyte leakage and sodium concentration of root, and a significant increase in proline, relative chlorophyll and antioxidant enzyme activity ameliorated the negative effect of salinity stress and improved plant growth.