2012年7月选取宁夏银川、沙坡头和甘肃民勤3个样地，分0-10、10-20、20-30、30-40、40-50 cm 5个土层采集蒙古沙冬青(Ammopiptanthus monglicus)根围土壤样品，研究了 AM 真菌物种多样性和土壤因子生态作用。共分离 AM 真菌4属36种，其中，球囊霉属(Glomus)19种，无梗囊霉属(Acaulospora)13种，盾巨孢囊霉属(Scutellospora)3种，多孢囊霉属(Diversispora)1种。黑球囊霉(G.melanosporum)是银川和沙坡头优势种，网状球囊霉(G.reticulatum)是民勤优势种。民勤孢子密度、种丰度和物种多样性最高，孢子密度和种丰度随土层加深而递减，在0-20 cm土层达最大值。总球囊霉素(TEG)和易提取球囊霉素(EEG)含量在3个样地均随土层加深而降低。孢子密度与土壤有机质、碱解氮、速效钾显著正相关，与总球囊霉素极显著正相关。结果表明，AM真菌物种多样性具有明显空间异质性，并与土壤环境密切相关，这为筛选优良菌种，充分利用AM真菌资源促进沙冬青生长和荒漠植被恢复提供了依据。%Arbuscular mycorrhizal fungi (AM) are important functional components of ecosystems. In order to elucidate the diversity and distribution of AM fungi in the rhizosphere of Ammopiptanthus monglicus, soil samples in the rhizosphere of A. monglicus were collected from three samples sites (Yin Chuan, Sha Potou and Min Qin) and divided into five layers on the basis of depth, from top to bottom: 0-10, 10-20, 20-30, 30-40, 40-50 cm in July 2012. In this study, 36 species of AM fungi were isolated from four genera isolated in three sampling sites. Among these species, nineteen of them belonged to Glomus, thirteen of them to Acaulospora, three of them to Scutellospora and one of them to Diversispora. AM fungal species diversity was closely related to the soil environments. G.melanosporum was the dominant species in Yinchuan and Shapotou, G.reticulatum was the dominate species in Min Qin. AM fungal spore density, species richness and species diversity were the highest in Min Qin site, and the value was maximum in the 0-20 cm soil layer and decreased with soil depth. The contents of total extractable glomalin (TEG) and easily extractable glomalin (EEG) also decreased with layers deepened. The correlation analysis showed that spore density had a significant positive correlation with soil organic matter, available N, available P, and TEG. The results showed that the AM fungal species diversity has obvious spatial distribution of heterogeneity and closely related with soil environments.
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