酸雨与重金属复合胁迫对绞股蓝抗性生理指标的影响

摘要

A pot experiment was conducted to study the effects of single or combined stress of Zn (30, 400 mg/kg), Cd (1, 15 mg/kg) and acid rain varying in pH value on physiological indexes of resistance of Gynostemma pentaphyllum.The results showed that with the increase of acidity of acid rain and concentration of metal ( Zn or Cd) , the malondialdehyde ( MDA) content and peroxidase ( POD) activity in leaves of Gynos-temma pentaphyllum increased , and the superoxide dismutase ( SOD ) activity increased firstly and then de-creased .The catalase ( CAT) activity decreased with the increase of acidity of acid rain , but increased firstly and then decreased with the increase of heavy metal ( Zn or Cd ) concentration .The combined stress effect of high-acidity acid rain and high -concentration Zn-Cd on physiological indexes of resistance of Gynostemma pentaphyllum was greater than their single factor effect , which showed obvious synergistic effect .Regardless of the acigity of acid rain , the combined stress effects of low concentrations of Zn -Cd on physiological indexes of Gynostemma pentaphyllum was less than their single effect , so it showed obvious antagonistic effect .%通过盆栽试验，研究了不同pH值的酸雨与Zn（30、400 mg/kg）、Cd（1、15 mg/kg）单独或复合胁迫对绞股蓝抗性生理指标的影响。结果表明：随着酸雨酸度和重金属（ Zn或Cd）浓度的增加，绞股蓝叶片中丙二醛（MDA）含量和过氧化物酶（POD）活性上升，超氧化物歧化酶（SOD）活性先升高后下降，过氧化氢酶（ CAT）活性随着酸雨酸度的增加而降低，随重金属（ Zn或Cd）浓度的增加先升高后下降；高酸度的酸雨与高浓度的Zn-Cd复合胁迫对绞股蓝各抗性生理指标的效应大于这3种污染物的单因素效应，表现出明显的协同效应；不管酸雨酸度强弱，低浓度的Zn-Cd复合胁迫对绞股蓝各抗性生理指标的效应小于Zn、Cd单因素效应，表现出明显的拮抗效应。