The structure of rhizosphere soil and endophytic fungal communities associated with Stipa purpurea and their correlation with soil environmental factors

Abstract:

[Objective] The aim of this study is to explore the fungal community structures associated with rhizosphere soil, root and leaf of Stipa purpurea, and the relationship between rhizosphere soil fungal community structure and soil environmental factors. [Methods] We collected soil and plant samples from three different sites which located in the Qinghai-Tibetan Plateau. Soil physiochemical properties and enzymatic activities were detected by using the methods of soil chemistry, and rhizospheric and endophytic fungal community structures were analysed by Illumina Miseq high throughput sequencing technology. Based on this, we resolved the composition and richness, Alpha diversity and the characteristics of fungal community structures. Meanwhile, we also analyzed the correlation between the diversity of rhizosphere fungi and the soil environmental factors, and clarified the soil environmental factors which effected the rhizosphere mycobiota structure of Stipa purpurea. [Results] The results showed that rhizosphere soil pH were neutral or leaning alkalinity of three sampling sites, soil physiochemical properties and enzymatic activities changed differently in different sites. We obtained a total of 314801 effective sequences and 4611 OTUs by high throughput sequencing, the diversity and richness of fungal communities were the highest in GanSu site, and the lowest in XiZang site. The fungal communities' dominant phyla of all samples were Ascomycota and Basidiomycota, accounting for 88.28% of the total. The endophytic fungal communities had significant variations in different sampling sites, while rhizosphere soil fungal communities had no obvious differences in three sites. Correlation analysis showed that the diversity of fungal community was significant positive correlated with soil pH, the contents of available K, Fe, Ca, Mg, and soil peroxidase, soil polyphenol oxidase, soil dehydrogenase, while significant negative correlated with altitude and soil acid phosphatase. Redundancy analysis indicated that different fungal communities corresponding different impact environmental factors. [Conclusion] A wide variety of fungal communities are associated with the roots, leaves and rhizosphere soil of S. purpurea. The fungal assemblages are influenced by multiple soil environmental factors, and different fungal communities have different influencing factors. This study was significant to the exploitation of the beneficial microbial resource, and also providing a theoretical basis for the conservation and reasonable development these natural grasslands.

Key words:Stipa purpurea;fungal community;soil chemical and physical properties;high-throughput sequencing;Qinghai-Tibetan Plateau