重铬酸钾对豌豆根尖细胞的遗传毒性研究

Study on Genotoxic Effects of Potassium Dichromate on Root Tip Cells of Pisum sativum

研究重铬酸钾对豌豆根尖细胞的遗传毒性效应。以豌豆根尖为试验材料,用不同浓度的重铬酸钾溶液分别处理豌豆根尖12、24、36 h,采用根尖压片法,测定豌豆根尖细胞的有丝分裂指数、微核率和染色体畸变率。在一定的试验浓度范围内,随着重铬酸钾浓度的升高,豌豆根尖细胞微核率和染色体畸变率升高;但浓度过高则下降。不同处理组的豌豆根尖细胞微核率显著高于对照（P〈0.05）。在低浓度（0～50 mg·L^-1）时,染色体畸变率随处理时间延长而增大;而高浓度（100和200 mg·L^-1）时,染色体畸变率随处理时间延长而降低。随着浓度（25～200 mg·L^-1）的增加和处理时间延长,有丝分裂指数下降,在有丝分裂过程中出现微核、染色体断片、C-中期等多种畸变类型。

The genetic toxicity effects of potassium dichromate were studied by using Pisum sativum root tip cells. The root tips of Pisum sativum were treated separately with different concentration Potassium dichromate for 12,24,36 h and the mitotic index,micronucleus rate and chromosome aberration rate were determined by root tip pressing flake method. Within certain range of concentration of Potassium dichromate the micronucleus rate and chromosome aberration rate were found to be increased with the increase of potassium dichromate concentration,but beyond this range that decreased with further increase of potassium dichromate concentration. The rate of micronucleus in different treatment groups were significantly higher than the control groups（ P〈0. 05）. The chromosome aberration rate was found to increase with treatment time at low concentration（ 0- 50 mg·L^-1）,and to decrease at high concentration（ 100 and 200 mg·L^-1）. The mitotic index was found to decrease with the increase of concentration（ 25- 200 mg·L^-1） and treatment time. The micronucleus,fragment,Colchieine-metaphase and various types of aberration were caused in cells mitosis.