Micro-community associated with ectomycorrhizalRussulasymbiosis and sporocarp-producingRussulain Fagaceae dominant nature areas in southern China

Abstract

Russula griseocarnosa, an ectomycorrhizal (ECM) fungus, is a 15 species of precious wild edible mushrooms with very high market value in southern 16 China. Its yield is affected by many factors including the tree species and 17 environmental conditions such as soil microbiome, humidity. How the microbiome 18 promotes the ECM fungus symbiosis with Fagaceae plants and 19 sporocarp-producing has never been studied. In this study, we collected rhizosphere 20 samples from Fujian province, the microbiota in the root and mycorrhizal 21 rhizosphere were identified by Illumina MiSeq high-throughput sequencing. First, 22 we compared three types of fungal communities: root tips infected with ECM 23 Russula (type 1), tips with Russula sporocarp (type 2) and tips without ECM (type 24 3). Our results showed that the fungal richness was negatively correlated with 25 Russula. Russula, Tomentella and Lactarius were common in Fagaceae ECM roots. 26 As to the mycorrhizal interactions, Boletus may be considered as an indicator 27 species for sporocarp-producing Russula, and Acremonium, Cladophialophora were 28 associated with Russula symbiosis. Second, we analyzed the fungal and bacterial 29 communities in rhizosphere soils from the corresponding to previously three types 30 (type 1, 2, 3). Dacryobolus and Acidocella may be considered as an indicator 31 species for sporocarp-producing Russula. Fungi Tomentella, Saitozyma, 32 Elaphomyces and bacteria Acidicaldus, Bryobacter, Sorangium and Acidobacterium 33 occurred more frequently in the ECM Russula rhizosphere. Furthermore, the 34 indicators Elaphomyces, Tomentella, Sorangium had a positive correlation with 35 Russula symbiosis by network analyses. Overall, our results suggest a relationship 36 between micro-community and ECM Russula formation and Russula sporocarp, 37 which may provide new strategies for improving Russula symbiosis rate and 38 sporocarp production.39