The Species Diversity Of Arbuscular Mycorrhizal Fungi In Plant Communities At Different Altitudes In Fanjingshan National Nature Reserve

Arbuscular mycorrhiza fungi(AM fungi)is one of the important components of terrestrial ecosystem,which plays an irreplaceable role in vegetation restoration,ecological balance,biodiversity protection and so on.However,at present,the diversity of AM fungi in China is less,and the research on AM fungi germplasm resources needs to be deepened.Fanjingshan National Nature Reserve(FNNR),located in the northeast of Guizhou Province,is one of the five nature reserves in China.FNNR belongs to subtropical primary forest ecosystem,which is a rare place to study biodiversity.In this study,we investigated the AM fungi species and distribution of several typical plant communities in different altitude gradients of FNNR,and explored the distribution rule of AM fungi in different habitats of subtropical forest ecosystem.The results will enrich the species resources of AM fungi in China.Five plant communities(Acer 2200-2300 m,Rhododendron Fargesia 2100-2200 m,hemlock 1300-1400 m,Castanopsis 700-1000 m and Cunninghamia 500-700m)were collected from the rhizosphere soil of different altitudes in FNNR.The spores of AM fungi were separated by wet sieve decantation and sucrose centrifugation,and the species identification of AM fungi was carried out by using spore morphology and nested PCR technology to amplify the target gene segment sequence comparison method,and the diversity of AM fungi in different plant communities was analyzed by using statistical method.The main results and conclusions are as follows:1.There are abundant species of AM fungi in FNNR.Through the identification of spore morphology,39 species of 11 genera,6 families,3 orders were identified,accounting for 75%,50%,30% and 12% of the known orders,families,genera and species in the world at present,accounting for a quarter of the known species in China.13 species of AM fungi belonging to 7 genera were identified by molecular biological methods.2.Among the five plant communities,the dominant genera are Acaulospora,the subdominant genera are Glomus,Sclerocystis,and Ambispora,and the rest are common or occasionally genus.Ac.mellea,Gi.margarita,Am.reticulata are common species of plant communities.3.The species distribution of AM fungi is related to the species and richness of vegetation,especially the specific selection between AM fungi and plant hosts.The dominant and endemic species of AM fungi in different plant communities of FNNR are different,and their species composition is also different.The species diversity index of AM fungi in different plant communities from high to low is Chinese fir community,Castanopsis community,hemlock elongata community,Rhododendron arrow bamboo community and maple community.4.The altitude has a significant effect on the distribution of AM fungi in FNNR.From the top of FNNR to the foot of FNNR,the main distribution of AM fungi changed from Acaulospora to Glomus and Sclerocystis.5.Soil factors can affect the diversity and community composition of AM fungi,and the preference for soil factors varies among different AM fungal species.Spore density,Shannonwiener index,and Simpson index were positively correlated with soil p H,and negatively correlated with Organic Matter,Total-N,Alkeline-N,Olsen-P,and Available-K.Total-P was less correlated with spore density,and negatively correlated with Shannon-wiener index,Simpson index,and Pielou uniformity index.Glomereras and Diversisporales AM fungi may have different soil factor adaptations.The results showed that the species resources of AM fungi in FNNR were very rich,and their distribution in community structure was affected by vegetation type,soil factors,climate and other factors.The diversity of AM fungi in different plant communities was significantly different.