Physiological Role of Osmoregulators Proline and Glycinebetaine in Increasing Salinity Tolerance of Chickpea

A pot experiment was performed at greenhouse, National Research Centre, Egypt, during winter seasons 2019/2020 and 2020/2021 to investigate the physiological role of two osmoregulators proline (5 mM and 10 mM) and glycinebetaine (10 mM and 20 mM) in alleviating the deleterious effect of salinity (3000 mg/l NaCl) on quality and quantity of chickpea plant (Sakha 4 cultivar). Salinity stress significantly decreased plant dry weight at vegetative stage, all components of photosynthetic pigments, seed yield accompanied by significant increases in osmo-protectant (proline and soluble carbohydrates) in dry leaves as well as phenolic content and antioxidant activity in the yielded seeds. Regarding proline and glycinebetaine effects, results indicated that all applied treatments caused significant increases in most of the investigated parameters of chickpea plants irrigated with either tap water or saline solution relative to corresponding control. It is worthy to mention that proline treatments were more effective than glycinebetaine treatments in increasing salinity tolerance of chickpea plants that reflected in its quality and quantity. Moreover, proline treatment at 5mM was the most pronounced treatment in alleviating the deleterious effect of salinity on chickpea plants.