Mitigation the Adverse Effects of Salinity on Red Bean Plants via Exogenous Application of Glycine Betaine, Zinc, and Manganese: Physiological and Morphological Approach

Since soil salinization is a concern all over the world, particularly in arid and semi-arid regions, the present study aimed to alleviate the adverse effects of salinity on red bean plants. A factorial experiment based on CRD design was conducted to investigate the effects of zinc (Zn; 0 and 25 ppm), manganese (Mn; 0 and 25 ppm), and glycine betaine (GB; 0 and 50 ppm) on the plants under three levels of salinity (0, 3, and 6 dS/m NaCl). The results showed that the plant growth indexes such as plant height, number of branches, number of pods per plant, and seed weight per plant significantly increased with the application of GB under salinity stress. Also, the applications of the GB, Zn, and Mn significantly increased the chlorophyll, protein, and proline contents, while decreased malondialdehyde (MDA), electrolyte leakage (EL), catalase (CAT), and superoxide dismutase (SOD) under salt stress, compared to the control. Based on the results, the GB, Zn, and Mn mitigated the adverse effects of salinity stress on red bean plants.