Effects Of CaCl₂ On Physiological Indexes Of Sour Jujube Seedlings Under NaCl Stress

【Objective】To explore the effects of Ca Cl2 on physiological indexes of sour jujube seedlings Under Na Cl stress.【Method】The experiment included three treatments:（i） no Na Cl stress（control）,（ii） Na Cl stress, and（iii） Na Cl stress plus Ca Cl2. The H₂O₂ concentration, O₂^- concentration in leaves, root activity, free water/bound water ratio, cell membrane permeability, MDA concentration, SOD activity, POD activity, CAT activity, soluble protein concentration, soluble sugar concentration, proline concentration, As A concentration, DHA concentration, GSH concentration and GSSG concentration were measured in the shoots and roots of the jujube seedlings. Principal component analysis was then used to select physiological indexes which could be used to evaluate the ability of Ca Cl2 to alleviate Na Cl stress.【Result】 1 Compared with the control treatment, Na Cl stress significantly increased H₂O₂ concentrations, O₂^-concentrations in leaves, cell membrane permeability, MDA concentrations, SOD activity, POD activity, CAT activity, soluble protein concentrations, soluble sugar concentrations, proline concentrations, As A concentrations and DHA concentrations in the shoots and roots of jujube seedlings. In contrast, Na Cl stress significantly reduced root activity, the concentrations of GSH and free water/bound water ratio in shoots and roots. The concentrations of GSSG decreased after rise under Na Cl stress. 2 Compared with the Na Cl stress, the Na Cl stress plus Ca Cl2 treatment significantly increased the root activity, free water/bound water ratio, SOD activity, POD activity, CAT activity, soluble protein concentrations, soluble sugar concentrations, proline content concentrations, As A concentrations, DHA concentrations, GSH concentrations and GSSG concentrations in shoots and roots. The Na Cl stress plus Ca Cl2 treatment significantly reduced cell membrane permeability and MDA concentrations in shoots and roots. The Na Cl stress plus Ca Cl2 treatment significantly reduced H₂O₂ concentrations, O₂^- concentrations in leaves.【Conclusion】Principal component analysis indicated that free water/bound water ratio, SOD activity, POD activity, CAT activity, soluble sugar concentration, soluble protein concentration, proline content concentration, As A concentration, DHA concentration, GSSG concentration and GSH/GSSG ratio can be used to evaluate the ability of Ca Cl2 to alleviate Na Cl stress in sour jujube shoots. In sour jujube roots, free water/bound water ratio, SOD activity, CAT activity, soluble sugar concentration, soluble protein concentration, proline concentration, As A concentration, GSH concentration, As A/DHA ratio, GSH/GSSG ratio and root activity are good indicators.