中文摘要：

丛枝菌根真菌（arbuscular mycorrhizal fungi,AMF）是自然生态系统和农业生态系统中分布最为广泛的土壤真菌,能够与绝大多数陆地植物形成互惠共生体并具有重要的生态功能。以内蒙古地带性植被区及甘肃、青海非地带性植被区荒漠和草原生态系统为研究对象,基于Illumina Miseq高通量测序平台比较荒漠和草原土壤AMF多样性和群落结构的差异,结合环境因子探讨其主要影响因素,以期为AMF在草原荒漠化生态恢复中的应用提供理论基础。基于高通量数据分析共得到159个AMF-OTUs,分属于1门1纲3目5科8属,其中Glomus属在荒漠和草原土壤中均为优势属。地带性植被区和非地带性植被区的草原土壤AMF丰富度、香农多样性、系统发育α多样性都显著高于荒漠。地带性植被区的荒漠和草原土壤AMF群落结构有显著差异,而非地带性植被区荒漠和草原土壤AMF群落结构没有显著差异。相关分析揭示了环境因子与土壤AMF群落结构和多样性的相关关系,变差分解的结果进一步表明,土壤理化性质和气候因子对AMF群落结构的解释率比植物群落和地理距离要高,荒漠和草原土壤AMF群落结构主要受土壤理化性质和气候因子形成的环境过滤的影响。

英文摘要：

Arbuscular mycorrhizal fungi（AMF） are ubiquitous soil fungi in natural and agricultural ecosystems,which can form symbiotic associations with the majority of terrestrial plants and have important ecological functions.To compare the AMF communities between desert and steppe ecosystems,and to reveal the key influencing factors for AMF diversity,we collected rhizosphere soil samples from both zonal and non-zonal desert and steppe in Inner Mongolia,Gansu and Qinghai provinces,China.The community structure of the soil AMF was investigated using Illumina Miseq sequencing platform.In total,159 AMF operational taxonomic units（OTUs） were detected,belonging to 1 class,3 orders,5 families and 8 genera,among which,Glomus was the dominant genus in both desert and steppe ecosystems.The AMF richness,Shannon diversity,phylogenetic diversity in steppe was higher than those in desert（both zonal and non-zonal vegetation regions）.A remarkable difference in AMF community structure between desert and steppe ecosystems was noted in zonal vegetation region.However,there was no significant difference in AMF community structure between non-zonal desert and steppe.Correlation analysis clearly reflected the relationship between environmental factors and AMF community structure and diversity,and variation partitioning showed that soil properties and climate factors were more important than plant community and geographic distance in determining AMF community structure.In summary,the soil AMF communities of desert and steppe were mainly shaped by soil properties and climate factors.This study provided support for the potential use of AMF for ecological control of grassland desertification.