醋酸铅对蚕豆根尖细胞微核率的影响

为研究铅对蚕豆根尖细胞遗传物质的损伤所用,以青皮蚕豆vicia faba L.为试验材料,通过蚕豆根尖细胞微核试验分析0.5~30mg·L~(-1)的醋酸铅对蚕豆根尖细胞微核率的影响,并计算污染指数。结果表明,蚕豆根尖细胞的微核率随染毒质量浓度的增加均呈上升的趋势,经30.0mg·L~(-1)醋酸铅染毒6h的细胞微核率显著高于对照组(P0.05),污染指数大于3.5,属于重度污染;经1.0~30.0mg·L~(-1)醋酸铅溶液染毒12h的细胞微核率均极显著高于对照组(P0.01),污染指数均大于3.5,属于重度污染;相同质量浓度醋酸铅溶液染毒处理6h后的细胞微核率均明显低于染毒处理12h组,但仅在质量浓度为1mg·L~(-1)时2组之间达到显著差异水平(P0.05)。研究显示,Pb2+可以通过蚕豆根尖的吸收而毒害细胞,引起细胞DNA损伤,且损伤程度随剂量的增加和时间的延长而加重。

Effect of Lead Acetate on Micronucleus Count in Root-tip Cells of Vicia faba

To determine the genetic injury on the root-tip cells of Vicia faba caused by lead in water,a micronucleus assay was conducted.The genotoxic effect of lead acetate in the concentrations ranging from 0.5 mg · L-1 to 30 mg · L 1 were monitored and pollution indices calculated.The results showed that micronuclei in the cells increased with increasing lead concentration.When the cells were exposed to lead acetate at the concentration of 30.0 mg · L-1 for 6 h,the number of micronuclei in the cells were significantly higher than that in control (P＜0.05).The pollution index was greater than 3.5,which was considered as a heavily polluted condition.Moreover,in the cases where the cells were treated with lead concentrations at 1.0-30.0 mg · L-1 for 12 h,similar results were observed at an extremely significant level (P＜0.01).At a same lead concentration,the 12 h treatments affected the cells significantly greater than the 6 h treatments.However,the difference was only at a significant level (P＜0.05) for 1 mg Pb · L 1.It seemed apparent that lead was absorbed to causegenetic injury to cells in the roots of V.faba,and the toxicity increased with dosage and time of the exposure.