Effects of Foliar Application of Nano-ZnO on Morpho-physiological Characteristics and Ionic Content of Salvia leriifolia Benth. under Salinity Stress

Salinity stress, like many other abiotic stresses, limits the plant growth. Nanotechnology has been globally accepted as a modern, advanced technology that could enhance research in many fields. In order to investigate the effect of Nano-ZnO and salinity stress on morpho-physiological characteristics of Salvia leriifolia Benth., a factorial experiment was conducted as completely randomized design with three replications, the treatments were three nano-ZnO concentrations (0, 2, 4 mg/l ) and five salinity levels (0, 50, 100, 150, 200 mM NaCl) in the greenhouse of Mashhad Islamic Azad University in 2019. The results showed that salinity stress had a significant effect on morpho-physiological indices as well as mineral nutrients. It was also found that 4 mg/l nano-ZnO concentration at the mild salinity stress (50 and 100 mM) increased leaf and root length, leaf and root soluble protein, and proline content compared to the control. Salinity stress also decreased the concentration of K+, Ca2+, Mg2+, Zn2+, Cu2+, P, and K+/Na+ ratio in roots and leaves, while Na+ content increased significantly during stress in both organs. Nevertheless, the application of nano-ZnO increased the content of Zn2+, Ca2+, K+, and K+/Na+ ratio in leaves and roots.