Diversity Of Arbuscular Mycorrhizal Fungi Around Plant Roots In Different Vegetation Zones And Its Correlation With Soil Factors In The Yellow River Delta

In this paper,the temporal and spatial distribution of AM fungi diversity in the rhizosphere of Suaeda salsa,Zostera japonica and Spartina aiterniflora were analyzed,and combined with high-throughput sequencing method,the effects of Spartina alterniflora invasion on fungal diversity in different vegetation zones of the Yellow River Delta were comprehensively discussed,so as to provide basis for the study of Spartina alterniflora invasion on the ecological environment management of the Yellow River Delta.The main results are as follows:(1)The Invasive Species Spartina alterniflora,compared with typical native plant species such as Zostera japonica and Suaeda salsa,has more advantages in growth and higher utilization and conversion efficiency of TOC,TN and TP in soil.The content of TOC and other nutrients in the growing area of Spartina alterniflora is generally higher than that of Zostera japonica and Suaeda salsa.With the increase of invasion years of Spartina alterniflora,the contents of TOC and other elements in the growing area of Spartina alterniflora increased.(2)Compared with stoichiometry,the growth of Spartina alterniflora was limited by N,while that of the above ground part of Suaeda salsa was mainly limited by N,and the underground part was mainly limited by P.(3)The colonization rate,colonization intensity and spore density of AM fungi in Spartina alterniflora showed the same trend.The colonization rate,colonization intensity and spore density of Spartina alterniflora and Suaeda salsa were the highest in summer,and the colonization rate,colonization intensity and spore density of Spartina alterniflora were generally higher than that of Suaeda salsa.And it increased with the increase of colonization time.The colonization rate and colonization intensity of Suaeda salsa were positively correlated with soil temperature.The colonization rate and colonization intensity of Spartina alterniflora were positively correlated with TOC,TN,TP,EEG,TEG,salinity and soil temperature.The spore density of Spartina alterniflora and Suaeda salsa was positively correlated with TOC,TN,TP and salinity,and negatively correlated with pH.The dependence of Spartina alterniflora on Glomalin was higher than that of Suaeda salsa and Zostera japonica.(4)There are abundant species of AM fungi in the rhizosphere of plants in the Yellow River Delta.The identified AM fungi are Glomeromycetes,and the identified AM fungi are Glomus.There are 395 OTUs in Glomeromycetes,and the number of OTUs is the largest.The second is Paraglomus,with 105 OTUs.Gigaspora and Diversispora have the least OTUs,with only three OTUs.The other genus were Acaulospora,Scutellospora and Archaeospora.The OTU numbers were 22,17 and 4 respectively.(5)The diversity of arbuscular mycorrhizal fungi was significantly affected by plant species.No Gigaspora was identified in Suaeda salsa growing area and bare beach area,and no Archaeospora was identified in Suaeda salsa growing area.However,the diversity of AM fungi was not significantly affected by seasons.Seven genus of AM fungi existed in three seasons.The diversity of AM fungi in Spartina alterniflora was lower than that in the Yellow River Delta.The fungal abundance and diversity of Spartina alterniflora gradually decreased with the increase of invasion years.(6)The species of AM fungi are closely related to environmental factors.At the genus level,through the correlation analysis between the AM fungi species in the top 50 abundance of plant rhizosphere and soil physical and chemical factors in the sampling area of the Yellow River Delta,7 genus of AM fungi identified in the samples had no correlation with soil an,AP,TN,TP and salinity.Among different genus of AM fungi,Archaeospora had no significant correlation with soil factors;Gigaspora had a positive correlation with TOC and TEG(p<0.05),and a negative correlation with pH(p<0.01);Diversispora had a positive correlation with TOC,TP,TN and EEG(p<0.05),and a positive correlation with TEG.There was a positive correlation between Scutellospora and C/N(p<0.05),and a negative correlation between them and pH(p<0.001);there was a positive correlation between Acaulospora and TOC(p<0.05),and a negative correlation between them and pH(p<0.001);there was a negative correlation between Glomus and pH(p<0.001)There was a negative correlation between Paraglomus and pH(p<0.05).In conclusion,the contents of TOC,TN and other nutrients in the growing area of invasive plant Spartina alterniflora were higher than those of typical local plants such as Zostera japonica and Suaeda salsa,and The nutrient elements of Spartina alterniflora increased with the invasion years.TOC,pH,TN,TP,EEG,TEG and C/N had different effects on AM fungi,and pH had the most significant effect on AM fungi.