Abstract:The resource and distribution of arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) in four sampling areas in Qiandongshan Pb-Zn mine,Fengxian County,Shaanxi Province,was investigated.(1)In the mine where the Pb and Zn concentrations were below the third level of national environmental quality standard,fifteen plant species were collected,and twelve of them were found establish dual symbiosis with AMF and DSE except for Pistacia chinensis,Quercus variabilis and Rumex acetosa.P.chinensis could only be infected by AMF,while Q.variabilis and R.acetosa could only be infected by DSE.However,the average AMF and DSE colonization of all plant species in the mine were low,only 32.3% (AMF) and 25.9% (DSE).In the slightly Pb and Zn polluted tailing wasteland,the average root colonization of AMF and DSE was 53.3% and 38.6%,respectively.In the moderately Pb polluted and severely Zn polluted tailing dam,the average AMF and DSE colonization was 68.3% and 54.2%,respectively.The average mycorrhizal colonization in tailing wasteland and tailing dam were higher than the control mine.In the severely Pb and Zn polluted abandoned smelter,the average AMF colonization decreased to 17.6%,but the DSE colonization still maintained at 60.3%.(2)The AMF spores in the four sites were maldistribution and the spore density per gram soil ranged from 0.08 to 6.84 and the average density per gram soil was 1.5.After we investigated the AMF and DSE colonization status of the common plants,Sophora viciifolia,Macleaya cordata,Artemisia brachyloba,and Saussurea tsinlingensis,we found that slight and moderate pollution promoted the establishment of the symbiotic relationship between AMF and their hosts.However,severe pollution inhibited the infection;No significant relationship was found between AMF spore density and colonization;DSE colonization was significantly positive correlated with soil Zn concentration (r=0.505,P<0.05),but had no significant correlation with soil Pb concentration.These results indicated that AMF and DSE commonly occur in Qiandongshan Pb-Zn mine,especially DSE has excellent heavy metal tolerance and adaptability.