Effects of Salicylic Acid on Physiological and Photosynthetic Characteristics of Waxy Corn Seedlings under Salt Stress
The waxy corn(Jinnuo 72)was selected as material to investigate the effect of exogenous salicylic ac-id on seedling physiological and photosynthetic characteristics under different soil salinity conditions.The results showed that compared with the control(P<0.05),the activities of catalase and superoxide dismutase in waxy corn seedling were significantly increased under 0.04%-0.52%soil salt content by 1 mmol/L salicylic acid treatment.The soluble protein content,soluble sugar content,and proline content in seedling were significantly increased un-der 0.04%-0.68%soil salt content(P<0.05).The malondialdehyde content in seedling was significantly decreased under 0.04%-0.68%soil salt content(P<0.05).The chlorophyll content and net photosynthetic rate in seedling leaves were significantly increased under 0.22%-0.35%soil salt content(P<0.05).The stomatal conductance in seedling leaves was significantly increased under 0.35%-0.52%soil salt content(P<0.05).The transpiration rate in seedling leaves was significantly increased under 0.22%-0.52%soil salt content(P<0.05).The intercellular CO2 con-centration in seedling leaves was significantly decreased under 0.22%-0.52%soil salt content(P<0.05).The salt tol-erance of waxy corn seedlings could be improved by exogenous salicylic acid through regulating antioxidant system,improving photosynthetic characteristics,increasing chlorophyll content,increasing osmotic substance content and decreasing malondialdehyde content.