Species composition and abundance of endorrhizal fungi in carex pensylvanica from Wisconsin sand prairies

Abstract

Wisconsin prairies are rare habitats characterized by sandy soils and sparse vegetation. Carex pensylvanica, the most abundant sedge in Wisconsin sand prairies, has generally been considered non-mycorrhizal. To better understand plant-fungal associations that may promote C. pensylvanica colonization in sand prairies, we characterized the diversity of endorrhizal fungi using culture-based and molecular approaches. Plants were collected in pairs along sand prairie/oak barren ecotones. Culturing data revealed 70 morphotypes of fungi, while Illumina sequencing of roots showed 362 OTUs, the most commonly isolated being Acephala harenae nom. prov. Cohabitation of dark septate endophytes, arbuscular mycorrhizal fungi, and ectomycorrhizae was determined within ~1cm root sections using light microscopy and Illumina sequencing. Tomentella ferruginea, Russula, and Laccaria were present in all samples sequenced. There was no significant difference in environmental factors or fungal community structure between tree and no tree sites. Soil data showed that ph and organic matter correlate with fungal community structure, the cause of which is unclear. To-date, this is the most in-depth survey of root associated fungi associated with any Carex species. Results provide insights into the diversity of fungi associated with sedges and the soil factors affecting fungal colonization in plants in sand prairie habitats.