A Study on the Cytotoxic and Genotoxic Effects of Rare Earth Multi-element Compound Fertilizer (RE-MECF) on Zea mays L.

为了研究常乐稀土多元复合肥对主要农作物--玉米(Zea mays L.)是否产生细胞毒性和遗传毒性效应,采用不同梯度质量浓度的稀土复合肥溶液对玉米进行处理,观察其根尖生长状况,统计分析细胞死亡率、微核率、有丝分裂指数以及对细胞DNA的损伤情况.结果表明,质量浓度为10mg·L-1以下时,常乐稀土复合肥能够促进玉米根尖的生长,100mg·L-1以上时抑制根尖生长;随着试验浓度的递增,细胞死亡率、微核率、DNA损伤率逐渐上升并具有正相关性,表现出明显的剂量-效应关系,而有丝分裂指数却随着浓度的增加逐渐下降.以上结果表明,常乐稀土复合肥对玉米确有一定的细胞毒性和遗传毒性效应,其细胞毒性阈值和遗传毒性阈值皆为100mg·L-1.The root tips were treated with different concentrations of Rare Earth Multi-element Compound Fertilizer(RE-MECF)in order to evaluate the effect on maize in terms of the growth of root-tip, the mortality, the frequency of micronucleus(FMN),mitosis index(MI)and DNA damage. The results indicated that the dosage below 10mg·L-1 (expressed by concentration of RE-MECF) could accelerate the growth of root tips of Zea mays L., but the groups which were treated by the dosages above 100mg·L-1 were repressed. The mortality, frequency of micronucleus(FMN)and DNA damage increased while mitosis index(MI)decreased with increasing concentrations, from which, the dosage-effect relationship was clearly demonstrated. These results suggested that the RE-MECF had certain cytotoxic and genotoxic effect, and that the cytotoxic and genotoxic threshold dosages were both 100mg·L-1.国家自然科学基金项目(No.30470421);; 江苏省高等学校自然科学基金项目(No.D180215