Study On The Diversity Of Forest Entomopathogenic Fungi In Hualong Mountain Nature Reserve

In this study,soil samples of different elevation gradients in Hua Long Mountain National Nature Reserve(HLMNNR)were collected and analyzed,in order to clarify the diversity and vertical distribution of forest fungi and entomopathogenic fungi in HLMNNR.And the entomopathogenic fungi were isolated from forest soil to provide a resource of fungal insecticides for biological control of insect pests.The soil samples were collected at different elevations in HLMNNR from 2018 to 2019,and insect species diversity was investigated at the corresponding altitude gradient.All of the soil samples were pretreated and were prepared the total DNA of soil microorganisms for high-throughput sequencing using ITS2 region meanwhile all soil samples were applied to use insect bait method to isolate insect pathogenic fungi.The main results are as follows:1.The composition structure of high(2200 m),medium(1800 m and 1400 m)and low(1000 m)elevations fungi and insect pathogenic fungi were significantly different,and each elevation gradient had its dominant fungi.Through MRPP index analysis,it was found that the influence of vertical spatial scale on the composition of fungi was significantly higher than that of horizontal spatial scale.And through the ? diversity and ? diversity analysis and the analysis of environmental factors db RDA/RDA at different elevations,it can be seen that the soil fungi at middle elevations have a higher diversity and are more abundant at lower elevations,and the fungi at lower elevations is the most uniform,while the species and richness of insect pathogenic fungi at lower elevations are the highest.The biggest driver of the difference is altitude.2.Combined with the number of insect species at different elevations and the abundance degree of entomopathogenic fungi Operational Taxonomic Units(OTUs),it showed a correlation between entomopathogenic fungi and insect species diversity in soil,indicating the diversity of forest insect species was influenced by the abundance of pathogenic fungi.3.There are abundant resources of entomopathogenic fungi in HLMNNR.Many fungal isolates have obvious virulence against mealworm larvae.Among these fungal isolates,the Metarhizium isolate 14003 shows high virulence against three forest beetle pests.