Study On AM Fungi Resources And Ecological Distribution Of Ulmus Pumila In Hunshandake Sandy Land

Ulmus Pumila is the top plant community in the Hunshandake Sandy Land,while Arbuscular mycorrhizal fungi(AMF)can survive in different ecological gradient environments and can coexist with most of the terrestrial vascular plants.The roots of plants were invaded,infected,and further developed into mycorrhizal fungi by the fungus AM fungi,and some mycorrhizal fungi had no vesicles,forming plexiform branches.Arbuscular mycorrhiza has important significance in promoting plant growth,improving plant stress resistance,enhancing the plant's absorption area and absorption rate of nutrients,improving community structure,and stabilizing the ecosystem.In this study,Hunshandake area was ensured as the research area,Ulmus Pumila was selected as the host plant,the three types of the AM fungi germplasm resources,geographical regularity and its correlation with environmental factors in Baiqi area,Zhenglan Banner and Keshiketeng Banner these three sites were investigated,and the ecological distribution characteristics,diversity changes and related impact factors of AM fungi in Hunshandake area were explored.The main results were as follows:(1)In this study,38 species of AM fungi were isolated from three plots,including 21 species of Glomus,belonging to dominant genus,9 species of genus Acaulospora,2species of Gigaspor,3 species of Scutella spora,1 species of Entrophospora,1 species of Archaseospora and 1 species of Claroideoglomus.A small number of the products could only be identified to the genus level.(2)The ecological distribution of different species of arbuscular mycorrhizal fungi in the rhizosphere of Ulmus Pumila was different,in which Glomus is not only the most abundant species,but also the most widely distributed.Glomus,Acaulospora and Scutellaspora were the common genus of the three plots,while Gigaspora was found only in Baiqi area and Zhenglan Banner.Archaespora leptoticha was present in Baiqi area.Both of Entrophospora infrequens and Claroideoglomus etunicatun only appeared in the Keshiketeng area.The species number of AM fungi ranged as follows Kashiketeng area >Zheng Lan Banner > Baiqi area.(3)The spore density of arbuscular mycorrhizal fungi in deffrent rhizospheric soil of Ulmus Pumila was 1.7~11.5/g,and the arbuscular mycorrhizal fungi were found in theroots of the three sample plots.The total infection rate was 56.7%~ 81.8 %,averagely64.1%,arbuscular infestation rate was 4.0% to 14.6%,vesicle infestation rate was 1.5% to30.7%,and mycelial infection rate was 21.6% to 62.1%.And mycorrhizal structure is Paris mycorrhiza type.The structure of the infestations around Ulmus Pumila was following:hyphae infestation rate > baculovirus infestation rate > arbuscular infestation rate.The spore density and infestation rate in Zhenglan Banner were the highest,then the Baiqi area,the lowest in Khishiteng Banner,similarily,the spore density and infestation rate in inter-district land were the highest,then the shady slope,the lowest in sunny slope.(4)There is no corresponding relationship between mycorrhizal infection rate and spore density,and there is no correlation between the two.Hyphae and vesicle infection rate and rainfall were positively correlated,while arbuscular branches and rainfall were negatively correlated.Spore density,species richness,and Shannon-Wiener diversity index were positively correlated with rainfall,and arbuscular infection rates and mycelium infestation rate,spore density and evenness index were negatively correlated with air temperature.Species richness,Shannon-Wiener diversity index and Simpson diversity index were positively correlated with air temperature,and the vesicle infestation rate was significantly positively correlated with air temperature.(5)Soil moisture content,pH,and organic matter in different areas were all different.The soil in the study area was alkaline soil.The vesicle infection rate was significantly positively correlated with spore density and negatively correlated with available nitrogen.There was a significant positive correlation between mycelia infection rate and total nitrogen and nitrate reductase,and a significant negative correlation with pH and species richness.The arbuscular branch infection rate was positively correlated with EEG,TEG,nitrate reductase and cellulase,and very significantly negatively correlated with polyphenol oxidase.Spore density was positively correlated with pH,and extremely significantly positive with EEG and TEG.Spore density was negatively correlated with available phosphorus and very significantly negatively correlated with available potassium.The Shannon-Wiener diversity index was significantly positively correlated with nitrate reductase and cellulase,and very negatively correlated with total nitrogen.The first principal component had the nformation content as high as 66.175%.The water content,organic matter,total nitrogen,available nitrogen,total phosphorus,organic carbon,TEG,available potassium,and pH are the key soil factors affecting arbuscular mycorrhizal fugi community species diversity in rhizospheric soil of Ulmus Pumila in Hunshandake.