The Diversity Of Arbuscular Mycorrhizal Fungi Associated With Pteris Vittata L. In The High Arsenic Ore Area In Northwest Guangxi

With the rapid development of industry and agriculture,arsenic pollution and arsenic poisoning are becoming increasingly prominent,which has become a worldwide pollution problem.Arbuscular mycorrhizal fungi(AM fungi)have a great application potential for Pteris vittata L.in improving arsenic contaminated soil remediation.However,the distribution and resource investigation of AM fungi living in heavy metal contaminated areas in our country are not comprehensive enough,so we need to strengthen the investigation of the relevant aspects.To explore the diversity of AM fungi in the arsenic contaminated area,the methods of field investigation and laboratory analysis were used to investigate the diversity and community composition of AM fungi associated with arsenic(As)hyperaccumulator Pteris vittata L.growing on As-contaminated soils under natural conditions.Five sites at different levels of arsenic contamination were selected in Nandan county,Guangxi province.The rhizosphere soil and root samples of Pteris Vittata L.were collected respectively.The key factors influencing the diversity of AM fungi were studied by the morphological method and Illumina MiSeq sequencing technology and CCA analysis.The main findings are as follows:1.4 generas and 10 species of AM fungi were isolated and identified in rhizosphere soil of Pteris Vittata L.in the 5 sites with the morphological method.There were 7 species belonged to Glomus,and they were G.aggrega,G.albidum,G.deserticila,G.flavisporum,G.glomerulatum,G.reticulatum,G.versiforme respectively.C.claroidem belonged to Claroideoglomus.F.constricum belonged to Funneliformis.S.nigra belonged to Scutellospora.Glomus was the dominant genus in the 5 sites.C.claroidem,G.glomerulatum and G.versiforme had the highest frequency,which was100.00%.2.With Illumina MiSeq sequencing technology,Glomus was the dominant genus in the 5 sites,accounting for 19.93%-99.76%in each site.The species composition and dominant species of AM fungi of Pteris vittata L.'s root in the 5 sites were quite different.Paraglomus sp.(VTX00308)and Glomus sp.(VTX00270)were the dominant species of R1,R2 respectively.Glomus sp.(VTX00057)and Glomus sp.(VTX00167)were respectively the dominant species of R3,R4 and R5.All of them belonged to Glomus,except for Paraglomus sp(VTX00308)that belonged to Paraglomus.3.With Illumina MiSeq sequencing technology,Glomus was the dominant genus in the 5 sites,accounting for 75.31%-99.80%in each site.The species composition and the dominant species of AM fungi of Pteris vittata L.'s rhizosphere soil in the 5 sites were quite different.Glomus sp.(VTX00055)and Glomus sp.(VTX00209)were respectively the dominant species of S1 and S2.Glomus sp.(VTX00057)and G.lamellosu.were the dominant species of S3,S4 and S5 respectively.All of them belonged to Glomus.4.51 species AM fungi were identified in rhizosphere soil and root of Pteris Vittata L.in the 5 sites.Among them,40 species AM fungi belonged to Glomus;4 species AM fungi belonged to Archaeospora;4 species AM fungi belonged to Acaulospora;2 species AM fungi belonged to Paraglomus;1 species AM fungi belonged to Gigaspora.There were more common species between soil sample and root sample in the same site.There were 16 common species between R1 and S1.There were 13 common species between R2 and S2.There were 17 common species between R3 and S3.There were 13 common species between R4 and S4.There were 6 common species between R5 and S5.Glomus sp.(VTX00115)had the highest frequency,which was 100.00%.5.Many soil factors could affect the diversity of AM fungi.There were positive correlation between pH and species richness and Shannon index.There were negative correlation between total nitrogen and species richness and Shannon index.There were negative correlation between total phosphorus and available arsenic and Shannon index.CCA analysis showed that total arsenic(R2=0.416,P=0.025),pH(R2=0.940,P=0.025),total nitrogen(R2=0.761,P=0.002),total phosphorus(R2=0.444,P=0.026),organic(R2=0.631,P=0.004)could significantly affect the composition of AM fungi community.