Species Diversity Of Arbuscular Mycorrhizal Fungi Of Different Plants In Extremely Arid Desert Environment Of AnXi

Anxi extremely dry desert national nature reserve in gansu province is located in central Asia temperate desert,desertification and typical desert,the desert ecosystem throughout the ancient Mediterranean region has certain typical and representative,and at present only in extremely arid desert ecosystem and biodiversity as the main protected object of nature reserve,the natural geographic and species evolution and global climate change has a special status in the study.The climatic conditions in the arid desert region of Anxi are extremely harsh,with few rainfall,poor plant species and fragile ecosystem.S.passerina,N.sphaerocarpa,R.soongorica,S.regelii,E.przewalskii as a typical vegetation type in this area,such as both root developed with drought tolerance,salt tolerance,cold resistance,wind resistance and other characteristics,an important role in ecological restoration.The vegetation exposed to extreme environments has evolved different strategies to overcome common stress conditions,such as establishing a symbiotic relationship at its roots.In the harsh desert habitat,mycorrhizal fungi(AMF)and plant symbiosis play an important role in promoting plant uptake and improvement of plant resistance.In addition,the large mycelium network system and the secretions such as globulin are of great significance to the material,energy exchange and information transfer between different components of the ecosystem.In this experiment,soil samples and root samples of five plant community root areas were collected in Anxi extremely dry desert state-level nature reserve in 2015,2016 and July 2017.The plant and soil factors were elucidated by combining optical microscope morphological methods.,We examined the connection of plant speciesand soil factors to elucidate the significance of AM in the desert ecosystem.For the effective containment of desertification process,the restoration of vegetation in desert areas to provide a reference.The main results are as follows:1.A total of 47 AM fungal species were isolated from the tested soil samples,Scu.nodosa was first detected in the desert environment of AM fungi.Of these fungi,17 species belong to Acaulospora,13 to Glomus,5 to Scutellospora,4 to Funneliformis,3 to Rhizophagus,2 to Claroideum,1 to Diversispora,1 to Entrophospora,1 to Ambispora.Scu.nodosa is the first reported species in this desert area.2.Extremely dry desert AM fungal spores presents is small in size,color depth,spore wall thickness,the spore surface appendages,surface ornamentation less close,but overall form spores are relatively full characteristics,showing xerophytic ecological adaptability of extreme arid environment.3.The diversity of AM fungi was significantly different in root regions of five plant species.Abundance of species and spore density were highest in S.passerina significantly,there were no significant differences between the three years annual.Five kinds of plant community in the spore density,species abundance and Shannon Weiner index change trend.4.Main component analysis was conducted on the distribution of AM fungal spores,and the distribution of different plants on PC1 and PC2 was dispersed.On PC1,the score of E.przewalskii was significantly higher than that of R.soongorica and S.passerina,and the score of S.regelii and N.sphaerocarpawere lower and the difference was not significant.On PC2,S.passerina scored the highest,followed by E.przewalskii and S.regelii,while R.soongorica and N.sphaerocarpa scored the lowest.The distribution of AM fungal spores among the five plant communities was significantly different between three years.5.AM fungi do not show strict specificity to host plants,but they have certain selectivity to host plants,and desert plants and AM fungi have certain mutual selectivity and preference.6.Plant species,soil organic C,pH,soil temperature and humidity,and alkaline phosphatase have significant influence on the composition and species diversity of AM fungal community.In order to study the symbiotic relationship between desert plants and AM fungi,this paper provides a basis for selecting the dominant species that are suitable for plant-mycorrhiza-soil optimal combination.