Physiological effect of exogenous salicylic acid on decreasing salt damage to pepper seedlings

In order to clarify the physiological and biochemical mechanism of exogenous salicylic acid in improving the tolerance of crops to salt stress,an experiment of pepper(Capsicum frutescens L.) was established.In the paper,the effects of different concentrations of exogenous salicylic acid with foliar spray on morphogenesis,physiological and biochemical characteristic under 150 mmol.L-1 NaCl stress was studied.Results showed that exogenous salicylic acid significantly improved stem height,number of leaves,stem diameter,fresh and dry weight and healthy index,markedly decreased the content of malon-dialdehyde(MDA),increased contents of free proline,soluble protein and activities of protected enzymes such as superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT).In different SA treatments,200 mg.L-1 SA was considered to be the optimum one.