水杨酸对盐胁迫下糯玉米幼苗生理和光合特性的影响

以糯玉米津糯72为试验材料,用水杨酸处理种子,研究水杨酸对不同含盐量土壤条件下的糯玉米幼苗生理和光合特性的影响。结果表明,1 mmol/L水杨酸处理比等量蒸馏水(CK)处理显著(P＜0.05)提高0.04%~0.52%土壤含盐量下糯玉米幼苗的过氧化氢酶和超氧化物歧化酶活性;显著(P＜0.05)提高0.04%~0.68%土壤含盐量下幼苗可溶性蛋白含量、可溶性糖含量和脯氨酸含量;显著(P＜0.05)降低0.04%~0.68%土壤含盐量下幼苗丙二醛含量;显著(P＜0.05)提高0.22%~0.35%土壤含盐量下幼苗叶片的叶绿素含量和净光合速率;显著(P＜0.05)提高0.35%~0.52%土壤含盐量下幼苗叶片的气孔导度;显著(P＜0.05)提高0.22%~0.52%土壤含盐量下幼苗叶片的蒸腾速率;显著(P＜0.05)降低0.22%~0.52%土壤含盐量下幼苗叶片的胞间二氧化碳浓度。外源水杨酸可通过调控抗氧化系统、改善光合特性、提高叶绿素含量、提高渗透物质含量和降低丙二醛含量提高糯玉米幼苗的耐盐能力。

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 acid 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 under 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 concentration in seedling leaves was significantly decreased under 0.22%-0.52% soil salt content(P＜0.05). The salt tolerance 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.