Genetic (non)-homogeneity of the bracket fungi of the genus Ganoderma (Basidiomycota) in Central Europe

During systematic surveys of urban, rural and forest areas in Slovakia and Moravia (Czech Republic) and occasional botanical excursions in Northern Hungary, seventy-five collections of Ganoderma spp. were gathered during 2015 – 2018. Taxa identification was accomplished through observation of morphological characteristics of their mature, sporulating and undeformed basidiocarps. The genetic diversity of the collections was investigated by using internal transcribed spacer (ITS1/4) of ribosomal DNA sequences comparisons. Both analyses showed that the 75 collections clustered into six clades, namely, G. applanatum, G. adspersum, G. resinaceum, G. pfeifferi, G. lucidum and G. carnosum in accordance with the morphospecies concept. The sequence comparison demonstrated genetic homogeneity of all G. resinaceum clade. Multiple sequence alignment indicated the presence of two G. resinaceum sequence types with significant statistic support and, probably, the existence of two cryptic taxa. The twenty-eight collections clustered with the G. applanatum group and the twenty other collections were grouped with morphologically very similar G. adspersum group. However, ITS sequences show no close similarity between these two species.