土壤铅和锌对植物根际丛枝菌根真菌分布的影响

从秦岭凤县铅锌污染区4种植物根际共鉴定出球囊霉属(Glomus)丛枝菌根真菌(Arbuscular mycorrhizal ungi,AMF)12种,其中缩球囊霉(G.constrictum)是该区域的优势种;缩球囊霉、副冠球囊霉(G.coronatum)、苏格兰球囊霉(G.caledonium)和聚丛球囊霉(G.aggregatum)对铅锌污染具有较强的耐性,而地球囊霉(G.geospo-rum)、台湾球囊霉(G.formosanum)、地表球囊霉(G.versiforme)和两型球囊霉(G.dimorphicum)对铅锌污染的耐性较弱.相关分析表明,土壤Pb、Zn、速效P浓度和pH较低时,对AMF丰度有一定的促进作用,当Pb、Zn、速效P浓度和pH较高时,对AMF丰度为抑制作用,AMF丰度与高浓度Pb呈极显著负相关,与高浓度速效P呈显著负相关.通径分析表明,Pb是影响秦岭重金属污染区AMF丰度的主要因素,其直接和间接作用都较大,而pH、速效P和Zn主要通过Pb的间接作用来影响AMF丰度.

Effects of Lead and Zinc in the Soil on the Distribution of Arbuscular Mycorrhizal Fungi

12 species of arbuscular mycorrhizal fungi were identified from the rhizosphere of 4 plants at diggings contaminated by lead and zinc in Feng County in the Qinling Mountains.They were all Glomus.G.constrictum was the dominant species in this area.G.constrictum,G.coronatum,G.caledonium and G.aggregatum were more resistant to heavy metals,while G.geosporum,G.formosanum,G.versiforme and G.dimorphicum were less resistant to heavy metals.Correlation analysis indicated that lower Pb,Zn,available P and pH advanced AMF species richness.However,higher Pb,Zn,available P and pH had negative effects on the AMF species richness.AMF species richness had negative correlation with higer Pb(P<0.01) and Zn(P<0.05) concentrations.Path analysis revealed that Pb was the main factor that affected AMF species richness in this area.Both its direct and indirect effects were big.pH,available P and Zn mainly affected AMF species richness through the indirect effect of Pb.