Morphological-anatomical characterization and molecular identification of Tomentella stuposa ectomycorrhizae and related anatomotypes

Species in the genus Tomentella (Thelephoraceae) belong to the most frequent and widespread ectomycorrhizal (EM) fungi found in temperate and boreal forests. Although several unidentified tomentelloid morphotypes have been presented as common members of EM communities in coniferous and broad-leaved forests, few tomentelloid EM have been identified and described in detail. In this study, ten tomentelloid EM isolates collected from Populus alba, Quercus cerris and Picea abies stands in Hungary and Germany are characterized and documented by morphological-anatomical methods using light microscopy. The investigated ectomycorrhizae belong to the same brown-black tomentelloid morphotype but form two different anatomotype groups (At I and At II). Molecular taxonomical identification was accomplished using phylogenetic analysis (neighbor joining method) of 49 Tomentella nrDNA-ITS nucleotide sequences including the 10 new and 39 GenBank sequences. The EM isolates clustered into two adjoining clades identical with the two anatomotypes. At II clustered with Tomentella stuposa while At I could not be identified to species. Based on the morphological similarity and the low genetic difference it must be a closely related taxon. A comparison of the recently known tomentelloid EM to T. stuposa is presented. Ecological questions involving abundance and host relationships are discussed.