Salinity stress is one of the serious environmental stresses that can influence crop growth and physiological and biochemical parameters. In this study, the role of vesicular and arbuscular mycorrhizal fungi ˈGlomus mosseaˈ and the putrescine polyamine in modulating the negative effects of salinity stress on physiological and biochemical parameters of strawberry plants were investigated. This study was done as a factorial experiment based on a completely randomized design with three replications in 2021 in the research greenhouse at the University of Jiroft. The studied factors included mycorrhizal fungi (0 and 30 g), putrescine (0 and 1.5 mM), and salinity levels (0 and 60 mM NaCl). Sodium (Na+) and potassium (K+) ions, and K+/Na+ in leaves and roots, photosynthetic pigments, relative water content (RWC), membrane stability index (MSI), reactive oxygen species (ROS), soluble sugar, anthocyanin, and proline in leaves were investigated. Simultaneous use of mycorrhizal fungi and putrescine by the more (170% compared to the control) accumulation of Na+ in the roots decreased their transfer to the leaves and by increasing the ratio of K+/Na+ in the leaves, it reduced the accumulation of ROS and, as a result, increased the MSI and also maintained leaf photosynthetic pigments. Salinity increased total soluble sugars and the use of putrescine caused the accumulation of proline and anthocyanin in the leaves. Therefore, modulation of the negative effects of salinity stress by mycorrhizal fungi and putrescine indicates successful adaptation of strawberry plants to salinity stress in the presence of mycorrhizal fungi and putrescine. Finally, our results recommend the use of mycorrhizal fungi in saline areas and provide an important perspective for the use of putrescine in modifying salinity tolerance.
