植物间作下根际微生物和土壤酶与土壤多氯联苯（PCB）降解的关系

以大豆、黑麦草和南瓜为材料,采用盆栽实验,研究了3种植物的单作和相互间作的不同种植方式对多氯联苯污染土壤的根际修复效应与机理。结果表明：（1）PCB去除率与土壤蛋白酶和磷酸酶活性均呈极显著正相关关系,相关系数分别为0.878和0.929（P〈0.01）,推测这两类酶可能参与了PCB的生物降解过程;（2）PCB去除率与土壤真菌密度呈显著相关（r=0.797）,而PCB去除率与土壤细菌及放线菌密度相关不显著;（3）在本实验条件下,微生物因素对土壤PCB的降解起主导作用,非灭菌土处理的土壤PCB去除率比灭菌土相对应的对照高出17.7%~30.75%;（4）根系分泌物能显著强化微生物的降解功能,添加黑麦草和大豆根系分泌物处理的土壤PCB去除率分别比只加营养液的对照高出21.4%和24.9%。

Effects of Rhizospheric Microbes and Soil Enzymes on the Biodegradation of PCB in the Soil Within Intercropping Systems

The effects of rhizosphere remediation on Polychorinated biphenyls（PCB）contaminated soil was studied through a pot-cultivation system with different combinations of three crops including ryegrass（Lolium perenne L.）,pumpkin [Cucurbita moschata（Duch.ex Lam.） Duch.ex Poiret] and soybean（Glycine max（L.）Merr.）.The results showed that：（1）Phosphatase and proteinase had an very significant positive influences on remediation rate of PCB in soil.It indicated that phosphatase and proteinase might be involved in the process of PCB＇s degradation.（2）The number of fungus also had an significant impact on the PCB elimination,but bacterium and actinomycete did not have significant effect.（3）The soil microorganisms played an important role in PCB＇s degradation.The removal of PCB from non-sterilized soil was higher than sterilized soil.（4）The root exudates could strengthen the PCB＇s degradation of microorganism.Regarding the removal of PCB from soil,the addition of root exudates from ryegrass and soybean were 21.4% and 24.9% higher than the control respectively.