Mico-Community associated with ectomycorrhizal Russula symbiosis and sporocarp-producing Russula in Fagaceae dominant nature areas in southern China

Russula griseocarnosa, an ectomycorrhizal (ECM) fungus, is a species of precious wild edible mushrooms with very high market value in southern China. Its yield is affected by many factors including the tree species and environmental conditions such as soil microbiome, humidity. How the microbiome promotes the ECM fungus symbiosis with Fagaceae plants and sporocarp-producing has never been studied. In this study, we collected rhizosphere samples from Fujian province, the microbiota in the root and mycorrhizal rhizosphere were identified by Illumina MiSeq high-throughput sequencing. First, we compared three types of fungal communities: root tips infected with ECM Russula (type 1), tips with Russula sporocarp (type 2) and tips without ECM (type 3). Our results showed that the fungal richness was negatively correlated with Russula. Russula, Tomentella and Lactarius were common in Fagaceae ECM roots. As to the mycorrhizal interactions, Boletus may be considered as an indicator species for sporocarp-producing Russula, and Acremonium, Cladophialophora were associated with Russula symbiosis. Second, we analyzed the fungal and bacterial communities in rhizosphere soils from the corresponding to previously three types (type 1, 2, 3). Dacryobolus and Acidocella may be considered as an indicator species for sporocarp-producing Russula. Fungi Tomentella, Saitozyma, Elaphomyces and bacteria Acidicaldus, Bryobacter, Sorangium and Acidobacterium occurred more frequently in the ECM Russula rhizosphere. Furthermore, the indicators Elaphomyces, Tomentella, Sorangium had a positive correlation with Russula symbiosis by network analyses. Overall, our results suggest a relationship between micro-community and ECM Russula formation and Russula sporocarp, which may provide new strategies for improving Russula symbiosis rate and sporocarp production.