【摘要】 本文以山西工矿区生黄土为供试土壤,以黑麦草(Lolium perenne L.)为供试植物材料,通过室内培养实验,采用变性梯度凝胶电泳技术(DGGE),研究不同浓度PAHs和HgCl2单一及复合污染种植黑麦草对土壤微生物群落多样性的影响.结果表明:不同浓度PAHs与HgCl2处理下黑麦草土壤微生物基因条带差异明显.与对照组相比,低浓度污染处理下基因条带数稍有增加,而高浓度污染处理下部分基因条带消失.各污染水平下土壤微生物所共有的优势条带较多.在HgCl2单一污染条件下,土壤微生物多样性首先随着污染浓度的升高而增加,污染浓度大于3 mg·kg-1时,土壤微生物群落多样性指数随着浓度的升高逐渐降低,在最高浓度60 mg·kg-1时,较对照组降低5.0%;PAHs单一污染与HgCl2单一污染处理下土壤微生物群落多样性指数表现出相似的规律,污染浓度大于10 mg·kg-1时,土壤微生物群落多样性指数开始降低,在最高浓度50 mg·kg-1时,较对照组降低了2.8%.HgCl2与PAHs复合污染在中浓度A22(PAHs 5 mg·kg-1、HgCl215 mg·kg-1)时对土壤微生物群落多样性表现为协同作用,而在最高浓度A36(PAHs 50mg·kg-1、HgCl260mg·kg-1)则表现为抑制作用.更多还原

【Abstract】 In this paper,taking the fresh mixed-loess soil in Shanxi mining areas and the ryegrass(Lolium perenne L.) as tested soil matrix and plant materials,respectively,through greenhouse culture experiments,the method of denaturing gradient gel electrophoresis(DGGE) was used to study the effects of single or combined polycydic aromatic hydracarbons(PAHs) and HgCl2 contaminated soil at different concentrations on ryegrass planting soil microbial community diversity.The results showed that microbial gene band numbers of the soil planted with ryegrass had obvious differences under different concentrations of PAHs and HgCl2 treatments.Compared with the control,gene band numbers at low concentrations treatment were increased slightly,while some gene bands at high concentrations treatment were disappeared.Many dominant bands were shared by the soil microbe under different contaminated level.Under the single contaminated condition of HgCl2,the microbial diversity indices increased with the increased contaminated concentrations.When the contaminated concentration of HgCl2 reached 3 mg·kg-1,the index increased to the top value.Till then the microbial diversity indices decreased with the increased contaminated concentrations of HgCl2.Compared with the control,it decreased by 5.0% at the highest concentration(60 mg·kg-1).The same tendency of the microbial diversity was displayed under single contaminated condition of PAHs.When the contaminated concentration of PAHs reached 10 mg·kg-1,it increased to the top value.Compared with the control,the microbial diversity decreased by 2.8% at the highest concentration(50 mg·kg-1).In the combined contaminated condition of PAHs and HgCl2,the coincident effect was showed on the soil microbial diversity under the middle concentration with PAHs of 5 mg·kg-1and HgCl2of 15 mg·kg-1,while the inhibited effect were exerted at the highest concentration with PAHs of 50mg·kg-1and HgCl2of 60 mg·kg-1.更多还原