酸雨与重金属复合胁迫对绞股蓝抗性生理指标的影响

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。

Effects of Combined Stress of Acid Rain and Heavy Metals on Resistant Physiological Indexes of Gynostemma pentaphyllum

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 .