Molecular diversity and phylogenetic affinities of symbiotic root-associated ascomycetes of the Helotiales in burnt and metal polluted habitats.

•  The diversity and phylogenetic affinities of symbiotic root-associated ascomycetes of the Helotiales are reported here based on ITS1-5.8S-ITS2 (internal transcribed spacer, ITS) nrDNA sequences. •  Mycobionts were obtained from roots of ericoid plants and grasses and from Piceirhiza bicolorata ectomycorrhizas (pbECM) on conifers and hardwoods, predominantly in burnt and metal-polluted habitats.