蒙古沙冬青伴生植物AM真菌多样性
Diversity of Arbuscular Mycorrhiza Fungi near to the Associated Plants of Ammopiptanthus mongolicus

为探究蒙古沙冬青（Ammopiptanthus mongolicus）伴生植物丛枝菌根（AM）真菌遗传多样性特征，于2013年7月随机取样采集内蒙古乌海、磴口和乌拉特后旗3个样地霸王（Zygophyllum xanthoxylum）和白刺（Nitraria tangutorum）根围土壤，利用变性梯度凝胶电泳（DGGE）技术对AM真菌群落结构、生态分布及与土壤因子的相关性进行研究。结果表明：（1）共分离鉴定球囊霉属（Glomus）、管柄囊霉属（Funneliformis）和根内球囊霉属（Rhizophagus）3属AM真菌，其中，Glomus为所有样地和土层共有优势属，G.coronatum（AJ276086.2）和G. sp.（KC558550.1）为霸王根围优势菌种，Uncultured Funneliformis（HG004455.1）和Uncultured Rhizophagus（KC797139.1）为白刺根围优势菌种；G.coronatum（FR773145.1）是乌海特有菌种，G.sp.（AJ315521.1），Uncultured Rhizophagus（KF386282.1）和Uncultured Glomus（HG972422.1）为磴口特有菌种。（2）不同宿主、样地、土层AM真菌具有不同的DGGE图谱特征，丰度和多样性指数呈现蒙古沙冬青>霸王>白刺；同一样地，0~30 cm土层高于30~50 cm土层；同一土层，乌海、磴口均高于乌拉特后旗样地，其中乌海20~30 cm土层AM真菌丰度和多样性指数最高，分别为16和2.06。（3）土壤速效磷与AM真菌多样性显著正相关，碱解氮、碱性磷酸酶与AM真菌群落多样性显著负相关。可见，AM真菌能与宿主植物形成良好共生关系，具有丰富的遗传多样性；宿主植物、环境因子对AM真菌群落多样性有重要影响。
Ammopiptanthus mongolicus is an excellent sand-fixation and endangered desert ecosystem of leguminous plants.Zygophyllum xanthoxylum and Nitraria tangutorum are associated plants of A.mongolicus that can not only adapt to the desert environment but also repair the ecological system.In order to explore the community composition and genetic diversity of AM fungi in the rhizosphere soil of Z.xanthoxylum and N.tangutorum by PCR-DGGE,in July 2013,the soil samples were collected from three different sites in Wuhai,Dengkou and Wulate of Inner Mongolia,China.Results showed that:(1) AM fungi have abundant genetic diversity.Three genera,including Glomus,Funneliformis and Rhizophagus,were isolated and identified in the rhizosphere soil of Z.xanthoxylum and N.tangutorum.Glomus was dominant genus of all the sample area and soil layer.The superiority strains of Z.xanthoxylum were G.coronatum（AJ276086.2）and G. sp.（KC558550.1）.Uncultured Funneliformis（HG004455.1）and Uncultured Rhizophagus（KC797139.1）were the dominant species of N.tangutorum.G.coronatum（FR773145.1）was a special species in Wuhai.G.sp.（AJ315521.1）.Uncultured Rhizophagus（KF386282.1）and Uncultured Glomus（HG972422.1）were unique species in Dengkou.(2) The fingerprint characteristics of DGGE,richness,diversity index and dominance of AM fungi varied with host plants,sampling sites and soil depth.Richness and diversity index of AM fungi were higher under A.mongolicus than under the associated plants and in 0-30 cm soil layer than that in 30-50 cm soil layer.For the same soil layer,the richness and diversity index of AM fungi were sequenced in a descending order in Wuhai,Dengkou,and Wulate.The highest richness and diversity index at 20-30 cm soil layer in Wuhai,reaching 16 and 2.06,respectively.(3) Soil available phosphorus