重铬酸钾对黑麦的细胞遗传毒性及硅的缓解作用

为了解K2Cr2O7的细胞遗传毒性及硅对铬毒害的缓解作用,采用常规染色体压片技术,观察不同浓度的K2Cr2O7(20、40、60、80、100、120mg.L-1)对黑麦根尖细胞有丝分裂的影响以及硅对铬胁迫缓解效应。结果表明,细胞有丝分裂指数、微核率和染色体畸变率均随K2Cr2O7浓度的升高呈先升后降趋势,在K2Cr2O7浓度为40.0mg.L-1时均达到最大值。与蒸馏水对照相比,6个不同浓度K2Cr2O7胁迫处理的微核率和染色体畸变率均有显著升高。对40mg.L-1 K2Cr2O7胁迫的黑麦根尖分别进行60、120和180mg.L-1的Na2SiO3处理,细胞有丝分裂指数、微核率和染色体畸变率均显著降低,且随硅浓度的增加呈下降趋势。说明K2Cr2O7对黑麦根尖细胞有丝分裂在低浓度时促进,高浓度时抑制,高低浓度处理均对染色体具有明显的致畸效应。外源硅可有效缓解K2Cr2O7对黑麦根尖细胞有丝分裂的不利影响。

Cytogenetic Toxicity of K2Cr2O7 on Rye and Mitigatory Effect of Silicon

Cytogenetic toxicity of K2Cr2O7 on rye and mitigatory effect of silicon were studied.The mitosis index,micronucleus frequency and chromosome aberration rate of root tip cells of rye were investigated under treatments of different concentrations of K2Cr2O7.The results showed that the mitosis index,micronucleus rate and chromosome aberration rate increased gradually in the root tips of rye along with the increasing of K2Cr2O7 concentration in the range of 0~40 mg·L-1,while these index reduced gradually along with the increasing of K2Cr2O7 concentration in the range of 40~120 mg·L-1.There were significant differences between the treatments and the no-treatment.The mitosis index,micronucleus rate and chromosome aberration rate of root tips of rye under K2Cr2O7(40 mg·L-1) stress reduced significantly with increasing concentration of Na2SiO3(0~180 mg·L-1).There were significant differences between Na2SiO3 treatments and the no-treatment.The conclusion of this study was that K2Cr2O7 had obvious teratogenic effect on root tip cells of rye,however K2Cr2O7 at low concentration could promote the mitosis in root tip cells of rye,but K2Cr2O7 at high concentration could restrain the mitosis.Silicon could relieve effectively the effect of K2Cr2O7 on the mitosis in root tip cells of rye.This could provide some reference for prevention of chrome pollution and application of silicon fertilizer.