稀土铈对芥菜生理效应及其土壤酶系统影响研究

Effect of Cerium on Physiological Effects and Soil Enzymes of Mustards

通过水培-土培实验,研究了芥菜在Ce的6个浓度梯度下的叶绿素含量、根系活力、抗氧化酶活性和土壤酶活性。结果表明:低浓度Ce处理能促进植物的生长,而当其超过某一浓度时则对植物起抑制作用,并对植物产生毒害,到土壤Ce含量为1500mg/L时,植株生长已受到明显抑制作用;植物的生理效应能很好的反映植株的健康情况,随着土壤Ce含量增加,芥菜中叶绿素含量、根系活力、SOD活性、POD活性、CAT活性总体上均呈现先上升后下降的趋势。当超过某一浓度(1500mg/L)后,Ce对芥菜的毒害作用随Ce浓度增加而增强;土壤酶活性不仅受到根际土壤环境的影响,而且不同种类的酶受到根际土壤影响的效应也不相同。芥菜根际土壤中,土壤脲酶、磷酸酶、纤维素酶、转化酶对Ce均表现为激活效应,而过氧化氢酶则表现为先激活后抑制。本研究旨在为芥菜对铈污染土壤的修复能力提供实验数据,同时进一步为受污区特别是稀土矿区的蔬菜食用安全提供科学依据。

Water-soil cultured experiment was utilized to study chlorophyll content,root vitality,antioxidant enzymes and soil enzyme activity of cerium of mustards at different concentrations.The results showed that：Low concentration of cerium could promote the growth of plantsBut once the concentration crossed a certain threshold would have inhibitory effects and produced toxic effects on plants.The growth of plants evidently inhibited until concentration in soil was 1500 mg L-1.The plants＇ health can be reflected through plant＇s physiochemical effects.With the increase of cerium content in soil,the chlorophyll content,root vitality,SOD activity,POD activity and CAT activity in plants increased firstly and then decreased in totally.The toxic effects of cerium to mustards will enhance with cerium content increasing after the concentration crossed a certain threshold（1500 mg L-1）.The activity of soil enzyme was affected by the rhizosphere soil environment.And different kinds of enzyme affected by the rhizosphere soil was also different.In the rhizosphere soil of mustards,the activity of urease,phosphatase,nvertase,cellulase all showed activation,while catalase activity showed activated at first and then restrained.The purpose of this study is to provide experimental data for mustards to repair cerium contaminated soil and further to provide scientific basis for vegetable food safety especially in rare earth mining area.