硒镉对番茄根尖细胞的遗传学效应

为研究硒镉联合作用对番茄根尖细胞遗传学效应，用不同硒浓度和100μmol/L镉联合处理番茄根尖24 h、48 h、72 h、96 h，统计有丝分裂指数、染色体畸变率和微核率.结果表明：单一镉处理时番茄根尖细胞有丝分裂指数下降，染色体畸变率和微核率增加，且随时间的延长而毒害加深.硒镉处理时，硒浓度低于1.0μmol/L时番茄根尖细胞有丝分裂指数增加，染色体畸变率和微核率下降，高于1.0μmol/L时番茄根尖细胞有丝分裂下降，染色体畸变率和微核率升高，但浓度过高时，微核率随着镉处理时间的延长反而有所降低，表现出低浓度硒对镉的毒害有缓解作用，高浓度硒与镉协同毒害作用.

Genetic effect of Selenium and Cadmium on Root Tipcell of Tomato

To study the genetic effect of selenium and cadmium on root tip cell of tomato,the root tips were exposed to selenium at different concentrations and 100 μmol/L cadmium for 24 h,48 h,72 h,96 h. The mitosis index,the frequency of micronucleus and chromosomal aberrations were counted. The results showed that the mitotic index decreased,the frequency of micronucleus and chromosomal aberration increased under the 100 μmol/L Cd stress,however,it was enhanced with treatment duration. When the concentration of Se was not higher than 1. 0 μmol/L,the mitotic index increased,the frequency of micronucleus and chromo-somal aberration decreased,when the concentration of Se was higher than 1. 0 μmol/L,the mitotic index decreased,the frequency of micronucleus and chromosomal aberration increased first then decreased. Se at lower concentration could alleviate the toxicity brought by Cd in the root of Tomato,but Se at higher concen-tration could enhance this toxicity.