应用蚕豆根尖微核技术研究3种重金属的遗传毒性

Utilization of micronucleus test technique in Vicia faba root tips to evaluate the genetic toxicity of three heavy metal ions

运用蚕豆根尖细胞微核技术,以微核率和有丝分裂指数为指标,研究不同浓度Pb2+、Cr3+和Cd2+对蚕豆根尖细胞的遗传毒性效应.结果表明,Pb2+、Cr3+和Cd2+在不同浓度下均可诱导微核的产生,其遗传毒性依次为:Cd2+>>Pb2+>Cr3+.在一定浓度范围内,微核率随重金属浓度的升高而增加,达到一定浓度后,微核率反而有下降的趋势.在一定低浓度条件下,蚕豆根尖细胞有丝分裂指数增高,高浓度下有丝分裂指数降低,意味着低浓度可促进细胞有丝分裂,高浓度则会抑制细胞有丝分裂.

Micronucleus test, micronucleus frequency and mitotic index of root tip cells of Viciafaba were used to study the genetic toxicity of different concentrations of heavy metal ions, namely Pb^2＋ , Cr^3＋. and Cd^2＋. The results showed that different heavy metal ions could induce the occurrence of micronucleus. The highest genetic toxicity was found for Cd^2＋ , the medium for Pb^2＋ and the lowest for Cr^3＋ . Within certain concentrations of different heavy metals, micronucleus frequency increased with the increase of concentration, and micronucleus frequency decreased at the highest concentration. Mitotic index increased in some certain low concentration and decreased in high concentration of heavy metal ions. The results implied that cell karyokinesis could be promoted at low concentration and be restrained at high concentration.