高Cu、高Zn对白星花金龟幼虫的毒性作用

Cu(铜)和Zn(锌)是环境中最常见的重金属污染元素,为探究其对白星花金龟幼虫的毒性,采用滤纸接触法、人工土壤法和菌渣培养法研究了高Cu、高Zn对白星花金龟幼虫的生长及氧化胁迫效应。结果表明,滤纸接触法和人工土壤法中试验浓度Cu、Zn对白星花金龟幼虫死亡率无明显影响。菌渣培养法中虫体的取食抑制率和体重增长抑制率均与Cu、Zn浓度呈显著性正相关关系;Cu处理诱导了虫体可溶性蛋白含量的增加,抑制了SOD(超氧化物歧化酶)、GST(谷胱甘肽转移酶)的活性和MDA(丙二醛)的产生,对CAT(过氧化物酶)活性没有显著影响;Zn浓度为3 500和5 000 mg·kg-1的处理组可溶性蛋白含量被显著诱导、MDA含量被显著抑制,浓度为2 000和6 500 mg·kg-1处理组的SOD活性被激活(P0.05),Zn胁迫未对CAT、GST活性造成明显影响。表明Cu、Zn污染对白星花金龟幼虫生长具有毒性效应,在评价高浓度的重金属污染对虫体的毒性作用时,不能仅采用SOD、CAT、GST等指标作为标志物,需要综合其他指标进行分析。

Toxicological Effects of Excessive Cu and Zn on Protaetia brevitaris Lewis Larvae

Three methods (the contact filter paper method, the artificial soil method and the edible fungi residue culture method) were used to study the toxic effects of Cu and Zn on Protaetia brevitaris Lewis larvae. The results showed that the concentration of Cu and Zn had no significant effect on the mortality of P. brevitaris larvae in the contact filter paper method and artificial soil method. In the edible fungi residue culture method, the feeding amount and body growth were significantly inhibited as the concentration of Cu and Zn increased, besides, the feeding inhibition rate and weight growth inhibition rate showed a significantly positive correlation with the concentration of Cu and Zn. The elements (Cu) applied to the P. brevitaris larvae induced the soluble protein content, inhibited the activities of SOD and GST and the content of MDA, and had no significant effects on the activities of CAT. The soluble protein content was significantly induced by 3 500 and 5 000 mg·kg-1 Zn, while the content of MDA was significantly inhibited. The SOD activities were induced by 2 000 and 6 500 mg·kg-1 Zn (P > 0.05). The CAT and GST activities showed no significant change with the Zn application. The results indicated that Cu and Zn had an ecotoxicological effect on P. brevitaris larvae. However, to estimate the toxicity of heavy metals with high concentrations to P. brevitaris larvae, except for SOD, CAT and GST as biomarkers, other indicators should be taken into account for a comprehensive analysis.