The Distribution Of Arbuscular Mycorrhizal Fungi And Dark Septate Endophytes In The Rhizosphere Of Ammopiptanthus Mongolicus

The endangered plant Ammopiptanthus mongolicus grown in the western arid desert ofInner Mongolia.It not only had economic value,but also had a higher ecological value,such aswindbreak and sand-fixation, and improved the fertility of soil etc,which could symbiosiswith fungi and improved the ecological environment. In the research, we based on thebackground and the target plant of4different sampling sites and A.mongolicus in the westernarid desert of Inner Mongolia.The symbiotic relationship between AM fungi and dark septateendophytic fungi were used as an entry point, we systemically studied on AM and fungal DSEdiversity, symbiotic relationship, spatial heterogeneity,ecological distribution regularity andcorrelation with soil factors, and first pure cultured and preliminary morphological identifiedDSE from the root in the rhizosphere of A.mongolicus. For making effective use of AM fungiand DSE strain resources, promoting ecological restoration and reconstruction of the desert.The results are as follows:5genera and22species of AM fungi were isolated and identified from the rhizosphereof A. mongolicus,9species belonged to Acaulospora, accounting for40.90%;8speciesbelonged to Glomus, accounting for36.36%;3species belonged to Funneliformis, accountingfor13.63%.2species belonged to Scutellospora and Entrophospora, respectively.The diversity of AM fungi was rich, and had regularity in spatial variation. The highestSpecies richness and Shannon Wiener index appeared in Alxa Left Banner. Evenness inDengkou was significantly higher than other three sites. Glomus were the dominant generaand G.reticulatum were the dominant species in different sites. Spore morphology of foursample sites were obvious difference, which had the xeric structure characteristics of deepcolor and surface ornamentation dense, we could be base on the morphological characteristicsof AM fungi for further Speculating that habitat and screening excellent AM fungi.5genera and54pure cultured DSE strains were isolated from the root samples of A.mongolicus in four sites, among which5genera were Geotrichum sp., Trichoderma sp.,Nigrospora sp., Monilochaetes sp.,Cladosporium sp., respectively. Cladosporium speciesonly distributed in4sampling sites.The root of A. mongolicus could form strong symbiotic relationship with AM fungi andintermediate-type arbuscular mycorrhiza. The average spore density reached123/10g soil,and the average total colonization was up to77.80%; the root of A.mongolicus also could be infected by DSE, the average total colonization were up to52.43%.The AM fungi and DSE fungi in the rhizosphere of A.mongolicus have a significantspatial distribution. the maximum of spore density and colonization rate of AM fungal hyphaeoccurred at0-10cm layer and decreased with the increasing of the soil depth; hyphacolonization rate of DSE and the colonization of Microsclerotia were significant differencesin four sampling sites. AM fungal total colonization was generally higher than DSEcolonization rate in the same sampling sites.Spore density and AM fungal total colonization was correlated with soil factors,whichhad significantly positive correlation with organic matter，available N,available P; totalcolonization of DSE was significantly positively correlated with organic matter, nitrogen,alkaline phosphatase.Principal component analysis showed that soil organic matter and soilurease reflects soil nutrient status in the Inner Mongolia desert. Path analysis revealed thatorganic matter directly affect the DSE colonization; alkali hydrolyzable nitrogen, andavailable phosphorus indirect effected the DSE colonization rate. Glomalin was closelyrelated with soil factors. Glomalin affect AM fungali colonization.