Study On The Diversity Of Arbuscular Mycorrhizal Fungi In The Subalpine Shrub Community Of Fanjing Mountai

Arbuscular mycorrhizal(AM)fungi have ecological functions such as expanding root range,promoting plant nutrient uptake and improving plant drought resistance,and the study of AM fungi species diversity can lay the foundation for the conservation and utilization of AM fungi species resources.In this study,we investigated AM fungi infestation in five different communities of subalpine shrub(Fargesia,FargesiaRhododendron,IIex bioritsensis-Symplocos lucida,Indocalamus,Hydrangea longipes)on the of Fanjing Mountain,isolated and identified AM fungi from the inter-root soil of different subalpine shrub communities,explored AM fungi germplasm resources in subalpine shrub community habitats,analysed AM fungi species diversity among different subalpine shrub community types.Soil factors were determined for each shrub community and the relationship between different soil factors and AM fungi diversity was analysed.The results are as follows :1.A total of 20 species of AM fungi spores from three orders,six families and eight genera were isolated and identified from the soil of subalpine shrub communities in the Fanjingshan Mountains,including nine species of Acaulospora,three species of Septoglomus,two species of Gigaspora and Ambispora;with one species each of Claroideoglomus,Archaeospora,Sclerocystis and Scutellospora.Acaulospora is the dominant genus in the inter-rhizosphere AM fungi of the subalpine shrub communities of the Fanjingshan Mountains;Sclerocystis and Scutellospora are common genera,and Acaulospora koskei is the dominant and widespread species in the subalpine shrub areas of the Fanjingshan Mountains.2.A new AM fungi species was identified and named as Gigaspora polymorphira.It has been registered in Fungal Names(FN570848)and Mycobank(MB#571077),and species details have been published to Phytotaxa in 2022.3.All the subalpine shrub communities in Fanjingshan can be infested with AM fungi to varying degrees.The total infestation rate ranged from 23.37% to 62.64%,with an average total infestation rate of 44.95%.The distribution and species diversity of AM fungi varied among the different subalpine shrub communities,with the highest Shannon-wiener,Simpson and Pielou indices in the Fargesia shrub community,The lowest was found in Indocalamus shrub,indicating that the community composition and diversity of AM fungi were influenced by plant community type.4.The evenness index,Shannon-Wiener index and Simpson index of AM fungi in Fanjingshan subalpine shrub were negatively correlated with soil p H,instant potassium,total phosphorus and effective phosphorus,and positively correlated with organic matter,total nitrogen and alkaline digestion nitrogen.This indicates that soil factors are important environmental factors affecting the diversity and community structure of AM fungi.