紫花苜蓿根系分泌物对土壤中OCPs的强化修复机制  

Remediation of OCPs contaminated soils with root exudates

作　　者：吴云霄[1,2] 王学乾 WU Yun-xiao;WANG Xue-qian(College of Life Science,Yan'an University,Yan’an 716000,China;Yan’an Key Laboratory of Ecological Restoration,Yan’an 716000,China)

机构地区：[1]延安大学生命科学学院,陕西延安716000 [2]延安市生态恢复重点实验室,陕西延安716000

出　　处：《云南大学学报（自然科学版）》2019年第6期1272-1278,共7页Journal of Yunnan University(Natural Sciences Edition)

基　　金：国家自然科学基金(31860110);陕西省自然科学基础研究计划(2015JM3121);延安市科技惠民计划(2017HM-05);陕西省大学生创新创业训练计划(S201910719077)

摘　　要：为探讨根系分泌物对土壤中有机氯农药(organochlorine pesticides,OCPs)的强化修复机制,以延安地区常见的紫花苜蓿(Medicago sativa.)为实验材料,利用模拟修复试验法,研究紫花苜蓿根系分泌物对土壤中OCPs的修复效果及途径.结果显示:在实验质量比(0~342.89 mg/kg)范围内,根系分泌物能够显著提高土壤中OCPs的去除率,并且在添加量为30~40 mL(每瓶约100 g污染土样)时强化去除效果最为明显;根系分泌物对OCPs去除的平均贡献率高达36.43%,明显高于非生物因素和土壤原有微生物;添加根系分泌物能够增加土壤中微生物的数量,并且在一定的污染浓度下,根系分泌物的添加量与土壤中微生物数量的增加量呈明显的线性正相关;根系分泌物通过改变微生物群落中各组分数量的变化,从而改变微生物群落结构,其中真菌和细菌受根系分泌物添加量的影响尤为明显;土壤中OCPs的去除浓度和根系分泌物的添加量呈一元二次曲线关系.因此,根系分泌物主要是通过改变土壤中微生物的数量及其群落结构来强化OCPs的修复效果.To study remediation of organochlorine pesticides(OCPs) contaminating soils with root exudates,alfalfa, which is common in Yan’an, was used as experimental material, and the method of simulated restoration experiment was used. The results showed that: ① Root exudates could significantly increase the removal rate of OCPs in soil, and the removal rate reached the highest when the amount of root exudates increasing from 30 mL to40 mL(about 100 g of contaminated soil sample per bottle), in the range of experimental concentration;② The average contribution rate of root exudates to OCPs removal was 36.43%, which was significantly higher than that of abiotic factors and soil original microorganisms. ③ The addition of root exudates could increase the number of microbes in soil, and there was a significant linear positive correlation between the addition of root exudates and the amount of microbes in soil at a certain pollution concentration;④ Root exudates changed the structure of microbial communities by changing the amount of the components in microbial communities, especially fungi and bacteria affected by root exudates. ⑤ There was a positive parabola relationship between the concentration of OCPs removal and the amount of root exudates. Therefore, root exudates could enhance the repairing effect of OCPs by changing the number of microbes in soil and their community structure.

关 键 词：根系分泌物 有机氯农药 紫花苜蓿 土壤微生物 

分 类 号：X131.3[环境科学与工程—环境科学]