叠氮化钠对玉米根尖细胞遗传毒性的研究

STUDY ON THE GENETIC TOXICITY OF SODIUM AZIDE ON MAIZE ROOT TIP CELLS

目的:以玉米根尖为材料,研究叠氮化钠对玉米根尖细胞遗传毒性的影响。方法:用不同浓度的叠氮化钠溶液(0.002 mmol/L、0.02 mmol/L、0.2 mmol/L)作为化学诱变剂,分别对玉米根尖进行8 h、16 h、24 h的染毒处理。采用常规染色体压片技术,在光学显微镜下观察玉米根尖细胞染色体结构变异情况,并测定玉米根尖细胞的有丝分裂指数,染色体畸变率和微核率。结果:叠氮化钠能影响玉米根尖细胞染色体的结构,出现了不同的畸变现象,包括多极、成环、桥(单桥和多桥)、滞后、不均等分裂、断片、微核等,并随着叠氮化钠溶液浓度升高和染毒时间加长,有丝分裂指数逐渐下降,染色体畸变率和微核率逐渐上升。结论:叠氮化钠对玉米根尖染色体的结构有影响,对玉米根尖有毒害作用,所以我们要合理地使用以叠氮化钠为原料的除草剂。

Objective: The effects of sodium azide on the genetic toxicity of maize root tip cells were studied. Methods: Different concentrations of sodium azide solution(0.002, 0.02, 0.2 mmol/L) were used as chemical mutagens to treat the root tip of maize at 8 h, 16 h and 24 h, respectively. The chromosomal structure variation of maize root tip cells was observed under a light microscope using conventional chromosome compression techniques. The mitotic index, chromosome aberration rate, and micronucleus rate of maize root tip cells were determined. RESULTS: Sodium azide could affect the chromosome structure of maize root tip cells, and there were different aberrations, including multipolar, ring formation, bridge(single and multi-bridge), hysteresis, inhomogeneous division, fragmentation, micronucleus, etc. As the concentration of sodium azide solution increases and the exposure time increases, the mitotic index gradually decreases, and the chromosome aberration rate and micronucleus rate increase gradually.Conclusion: This experiment demonstrates that sodium azide has an effect on the structure of chromosomes in maize root tips, and has obvious toxic effects on corn root tips. Therefore, we must rationally use herbicides based on sodium azide.