Species Diversity of Micromycetes Associated with Epipactis helleborine and Epipactis purpurata (Orchidaceae, Neottieae) in Southwestern Poland

The Orchidaceae family is a diverse family of flowering plants that occur naturally in most parts of the world. However, fungal communities inhabiting different parts of orchids are not sufficiently described. The aim of the study was to conduct a mycological evaluation of Epipactis helleborine and E. purpurata (Orchidaceae), which grow naturally in Lower Silesia (SW Poland), by identifying the species composition of the culturable micromycetes fungi on the surfaces of the plants and from the inner layers of the tissues. Fungi were identified based on a phenotypic and genotypic analysis. To our knowledge, this is the first such analysis. This study showed that more species of micromycetes were cultured from E. helleborine compared with E. purpurata. The flowering plants of E. helleborine were inhabited by the largest number of culturable fungal species (13 species), and the fewest species were isolated from the flowering plants of E. purpurata (eight species). Some of these fungal species may be pathogens of the plants. The surface tissues of the orchids were mainly inhabited by Mucor moelleri and/or Penicillium biourgeianum. The inner layers of these plants were the most colonized by Alternaria tenuissima and/or Arthrinium arundinis and/or Fusarium sporotrichioides. The relative dominance of these fungal species depended mainly on the development phase of the plants.