Diversity of fungal communities associated with mixotrophic pyroloids (Pyrola rotundifolia, P. media and Orthilia secunda) in their natural habitats

Abstract

As it was shown, mixotrophic plants (MxP) strongly depend on their mycorrhizal fungi for carbon, at least at the early stages of life cycle, and have rather high specificity for mycobionts. However, the diversity of fungi associated with MxP and their role in plant's life are still poorly known, especially under natural conditions. In the present study, the diversity of mycobionts of the three mixotrophic pyroloid species (Pyrola rotundifolia, P. media and Orthilia secunda) was investigated by sequencing nrITS from roots and rhizomes. At the same time, we studied ectomycorrhizal fungal communities of neighboring trees. The mycobiont diversity slightly differed berween the three species, but they also shared similar fungal taxa. The species of basidiomycete genera Tomentella, Piloderma, Russula and Mycena were dominant fungal partners of the studied pyroloids. The plants were also colonized by other ectomycorrhizal and saprotrophic basidiomycetes and ascomycetes. The research results showed MxP link to tree species by shared mycobionts and partial mycoheterotrophy by involvement into mycelial network. Thirty nine fungal taxa (at species and genera level) inhabiting pyroloid root system as mycobionts and root endophytes were detected. Their role for plant performance requires further investigation.