3种李属彩叶植物对NaCl胁迫的生理响应

以盆栽4年生紫叶李、紫叶矮樱、黑杆樱李幼苗为试材,设置土壤NaCl含量分别为0.042%(CK)、0.1%、0.2%、0.3%和0.4%的盐胁迫处理,研究3种李属彩叶植物盐害情况及其叶片膜质过氧化程度、抗氧化酶活性、有机渗透调节物质含量的变化,已明确它们的耐盐能力.结果表明:(1)随着土壤中NaCl含量的递增,3种彩叶植物的盐害指数和盐害率不断增大,上述三者盐害指数在50%时土壤NaCl含量分别是0.349%、0.261%和0.327%;(2)它们叶片细胞膜透性和氧自由基产生速率均迅速增加,并以紫叶李各处理的值最低且增加最慢;(3)各植物叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性变化均呈先上升后下降趋势,并均在土壤NaCl含量为0.2%或0.3%时达到峰值;(4)各植物叶片脯氨酸含量不断增加,可溶性糖含量先升高后下降,可溶性蛋白含量则先下降后升高.研究发现,3种李属彩叶植物均能在一定盐胁迫范围内通过自身保护酶系统和渗透调节物质有效降低活性氧的伤害,它们的抗盐性表现为紫叶李>黑杆樱李>紫叶矮樱;脯氨酸和可溶性糖可能是盐胁迫下3种植物的主要渗透调节物质.

Physiological Responses of Three Colored-leaf Species of Prunus under NaCl Stress

Four-years-old colored-leaf species of Prunus treated by NaCl were studied to explain their resistance to salt stress.The soil salt contents were set as CK (0.042%),0.1%,0.2%,0.3% and 0.4% respectively.Salt injury index,membrane lipid peroxidation,antioxidant enzyme activity and osmotic adjustment substance contents were detected.The results showed as follows:with the increased of soil NaCl content,salt injury index increased;Membrane lipid peroxidation and superoxide anion radical generating rate increased;Superoxide dismutase,peroxidase,catalase and ascorbate peroxidase increased firstly and then decreased with the increase of soil NaCl content;Proline and soluble sugar contents kept increasing,soluble protein reached the maximum value at 0.2% or 0.3%,and then turn to decrease.So we think that the proline and soluble sugar were the main osmotic adjustment substance in the 3 colored-leaf species of Prunus.According to the analysis of salt injury index and physiological-biochemical characteristic,we knew the resistance of 3 colored-leaf species to NaCl ranked from P.cerasifera