Effects of close-to-natural management on the community structure and diversity of fungi in the rhizosphere soil of rubber plantation

【Objective】To explore the changes in the composition and diversity of fungal species in the soil,rhizosphere and root surface of rubber plantations after close-to-natural management,so as to provide a theoretical basis for the restoration of rubber plantation biodiversity and the sustainable development of natural rubber.【Method】A fixed sample plot of 1 ha rubber plantation in the test site for close-to-natural management was established,at the same time,a sample plot of conventional treatment and a sample plot of herbicide treatment for comparative research were established to analyze the composition,diversity and community function of fungi in soil,rhizosphere and rhizoplane based on highthroughput gene sequencing.【Result】After close-to-natural management and herbicide treatment,the content of SOM and TP decreased,and the p H and water content increased. Ascomycota and Basidiomycota were the main dominant fungal groups in conventional plantation,near natural management plantation and herbicide treated plantation. After close-tonatural management,Ascomycota in rubber plantation soil decreased,and Ascomycota in rhizosphere and rhizoplane increased. PCoA analysis at OTU level showed that significant differences existed in species composition between soil and root surface(P<0.05). No significant difference in α diversity was found in fungi in soil,rhizosphere and rhizoplane of three rubber plantations.γ diversity analysis at OTU level showed that the total amount of fungal species in close-to-natural management plantation was higher than that in conventional plantation and herbicide treated plantation. RDA analysis showed that the main environmental impact factors in soil,rhizosphere and root surface were pH,TN and SOM. According to the functional prediction of FUNGuild,the main nutrient type of fungal communities in the soil,rhizosphere and rhizoplane of the three rubber plantations was saprophytic,and the content of saprophytic fungi in the soil was higher than that in the rhizosphere and rhizoplane. After close-to-natural management,the saprophytic fungi in rubber plantation soil decreased.【Conclusion】After near natural management,the water content and organic matter content of rubber forest increase,and the change of soil physical and chemical properties will influence the community structure and diversity of fungi to a certain extent,and increase the enrichment of fungi on the root surface.