不同程度铅锌污染区丛枝菌根真菌和深色有隔内生真菌侵染特征

Colonization Characteristics of Arbuscular Mycorrhizal Fungi and Dark Septate Endophytes in Different Degree Pb-Zn Polluted Areas

对陕西凤县铅硐山铅锌矿区4个不同程度铅锌污染样地植物根系的丛枝菌根真菌(AMF)和深色有隔内生真菌(DSE)进行了资源和分布调查。结果表明:(1)无铅锌污染的矿山上调查的15种植物中除黄连木没有检测到AMF侵染、栓皮栎和酸模不能被DSE侵染外,其他植物均能与AMF和DSE共生,但平均侵染率较低,仅分别为32.3%和25.9%;铅锌轻度污染的尾矿荒地和铅中度污染、锌重度污染的尾矿坝植物根系内AMF和DSE侵染率明显提高,AMF的平均侵染率分别为53.3%和68.3%,DSE的平均侵染率分别为38.6%和54.2%;铅锌重度污染的废弃冶炼厂样地植物AMF侵染率明显下降,平均只有17.6%,而DSE的侵染没有受重金属污染的抑制,仍达到60.3%。(2)4个样地植物根际土壤中AMF孢子分布不均匀,每克土的孢子密度在0.08～6.84个,平均为1.5个。对4个样地均有分布的狼牙刺、博落回、山蒿和秦岭风毛菊的AMF、DSE侵染状况调查发现,轻度和中度的铅锌污染能促进AMF与宿主共生关系的建立,而重度污染则显著抑制AMF侵染;AMF孢子密度没有呈现一定的规律性,且与AMF侵染率之间没有显著相关性;DSE侵染率与土壤锌含量存在显著正相关关系(r=0.505,P<0.05),而与土壤铅含量没有显著相关性。可见,AMF和DSE能够广泛存在于铅硐山铅锌矿区,尤其是DSE表现出较强的耐受性和适应性。

The resource and distribution of arbuscular mycorrhizal fungi （AMF） and dark septate endo- phytes （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 estab- lish dual symbiosis with AMF and DSE except ~or Pistacia chinensis ,Quercus variabilis and Rumex aceto- sa. 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 rootcolonization of AMF and DSE was 531 3%and 38.6% ,respectively. In the moderately Pb polluted and se- verely Zn polluted tailing dam,the average AMF and DSE colonization was 68.3%and 54.2% ,respective- ly. 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, So- phora vicii folia , Macleaya cordata , Artemisia brach：yloba , 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 infeetion; No significant relationship was found be- tween AMF spore density and colonizationl 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 ex- cellent heavy metal tolerance and adaptability.