Photobiont Inventory of a Lichen Community Growing on Heavy-Metal-Rich Rock

Abstract

The photobiont inventory of a stand of the Acarosporetum sinopicae, lichen community comprising saxicolous, chalcophilous lichens, has been analysed. Investigated lichen species were Acarospora rugulosa, A. sinopica, Bellemerea diamartha, Lecanora polytropa, L. subaurea, Lecidea silacea, L. lapicida, Rhizocarpon geographicum, and Umbilicaria cylindrical. For all these lichen species this is the record of the photobionts, except for L. lapicida. The photobionts were cultured axenically and investigated using light microscopical and molecular methods (ITS-sequence analyses). Every lichen species contained only one photobiont species. All photobionts belong to Trebouxia jamesii, but two different subspecies were found with the morphological differences corresponding to molecular differences. The new subspecies T. jamesii subsp. angustilobata is described, differing from the typical T. jamesii by a crenulate chloroplast but identical to the latter taxon in respect to the pyrenoid structure in the light microscope. These results are discussed with respect to the photobiont inventory of the Physcietum adscendentis, analysed in an earlier study.