Mitigation of salinity stress effects on growth, physio-chemical parameters and yield of snapbean (Phaseolus vulgaris L.) by exogenous application of glycine betaine

Pots experiment was carried out during season 2017 at greenhouse of the Agric. Bot. Dep., Fac. of Agric., Zagazig Univ., Egypt to evaluate the effect of glycine betaine (GB) application under salinity stress (50 and100 mM Nacl) on growth, physio-chemical analysis and yield of snap bean cv. Bronco. A complete randomized blocks design was used in this search with three replications. Growth parameters, chlorophyll content and green pod yield were significantly decreased with subjecting plants to NaCl. However foliar application of GB detoxified the stress generated by NaCl and significantly improved the above mention parameters. Salinity stress increased the electrolyte leakage (EL) and decreased membrane stability index (MSI) and relative water content (RWC). While foliar application of GB was improved MSI and RWC and minimized EL. Proline content and antioxidant enzymes significantly increased in the response to NaCl stress as well as GB application.