苏丹草根分泌物在有机氯农药降解过程中的作用

发布时间：2018-02-09 16:49

  本文关键词： 根际效应 有机氯农药 苏丹草 根系分泌物 土壤微生物　出处：《中国环境科学》2017年08期 　论文类型：期刊论文

【摘要】：采用模拟修复实验的方法,研究了苏丹草(Sorghum sudanense)根系分泌物对根际土壤中有机氯农药(organochlorine pesticides,OCPs)各残留组分的降解特征及其对根际微生物群落特征(数量、组成、结构及功能)的影响,探讨了根际土壤中微生物碳、微生物氮和群落结构的变化差异.结果显示,供试OCPs含量(66.67~343.61mg/kg)范围内,根系分泌物介导下的土壤-微生物系统对OCPs污染物去除的促进作用明显:添加根系分泌物20d后,"根际"土壤(TR_2)中OCPs去除率在高达79.32%,比无根系分泌物的OCPs污染组(TR1)高36.86%,比灭菌处理组(CK)高60.63%;相同处理条件(污染水平、添加剂量)下,根系分泌物对HCHs、毒杀芬、HCB、艾氏剂、γ-氯丹等组分的强化去除率总高于对OCPs的强化率(P0.05);对DDTs、灭蚁灵、硫丹Ⅰ、狄氏剂、环氧七氯等组分的强化去除率低于OCPs的强化率.相同污染水平下,"根际"土壤(TR_2)中土壤微生物碳、微生物氮也显著高于无根系分泌物的TR_1组;实验期间,细菌的磷脂脂肪酸含量占主导地位、真菌次之,其变化趋势与土壤中OCPs的降解特征相一致.可见,在OCPs降解过程中,根系分泌物改变了根际土壤中细菌、真菌等菌群的种群数量及群落结构,进而促进了OCPs的降解.
[Abstract]:The effects of root exudates of Sorghum Sudanensei on the degradation of organochlorine pesticides-OCPs in rhizosphere soil and on the characteristics of rhizosphere microbial community (quantity, composition, structure and function) were studied by simulated remediation experiments. The variation of microbial carbon, microbial nitrogen and community structure in rhizosphere soil was studied. The results showed that the OCPs content was in the range of 66.67 ~ 343.61 mg / kg. The effect of soil-microbial system mediated by root exudates on the removal of OCPs pollutants was obvious: after adding root exudates for 20 days, the removal rate of OCPs in "rhizosphere" soil (TR2) was as high as 79.32%, which was higher than that in OCPs polluted group without root exudates (TR1). 36.86% higher than that of sterilizing treatment group, 60.63% higher than that of sterilizing treatment group; the same treatment condition (pollution level, The enhanced removal rate of HCHs, toxaphene HCB, Aldrin and 纬 -chlordane by root exudates was higher than that on OCPs (P 0.05), and DDTs, mirex, endosulfan 鈪，

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