Hg、Cd复合污染对千屈菜生理生化指标的影响

Effects of Mercury(Hg)and Cadmiumm(Cd)Combined Pollution on the Physiological and Biochemical Indexes of Lythrum salicaria

以千屈菜为试材,研究了不同浓度汞(Hg)(0、0.5、5.0、50.0mg/L)及镉(Cd)(0、0.5、5.0、50.0mg/L)胁迫对其生理生化指标的影响。结果表明:低浓度Hg、Cd刺激千屈菜生长;随着Hg、Cd浓度的增加,叶绿素相对含量呈现小幅上涨而后下降;低浓度Cd2+对超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)活性有提高作用,但过氧化氢酶(CAT)活性随重金属浓度增加而下降,丙二醛(MDA)含量处于波动状态;随着Hg、Cd浓度的增加,细胞膜相对透性增加。Hg、Cd复合污染重于Hg、Cd单一胁迫处理。总之,千屈菜能够通过调节抗氧化系统来适应重金属环境,较耐Hg和Cd胁迫,是具有优良前景的环境治理及园林绿化水生花卉。

Thking Lythrurn salicaria as material,the effect of different concentrations o{ mercury （Hg） （0,0. 5,5. 0： and 50.0 rag/L） and cadmium （Cd） （0,0. 5,5.0 and 50. 0 mg/L） on the physiological and biochemical indexes of it were studied. The results showed that low coneentrations of Hg2＋ and Cdz＋ stimulated the growth of Lythrum salicaria. With the increase of Hg2＋ or Cd2＋ concentrations,relative chlorophyll content was slightly increased but then declined. Lower concentrations o{ C.d2~ could improve ascorbate peroxidase （APX） and superoxide dismutase （SOD） activities. But malondialdehyde （MDA） content fluctuated. CAT activity decreased with the increase of heavy metal concentration. Relative permeability of Lythrum salicaria cell membrane increased with increasing of Hg or Cd concentration. Hg2＋ and Ccl2＋ combined pollution were heavier polluiion than that of Hg2~ and CA2~ stress. In conclusion,Lythrum salicaria could adapt to heavy metal, especially for Hg and Cd, by regulating the antioxidant system. Lythrum salicaria had potential extensive application prospects in the environmental governance and landscaping.