DNA barcoding of wild Ganoderma specimens and cultivated strains in Hungary

Abstract

The cosmopolitan polypore genus Ganoderma (Polyporales, Basidiomycota) has an enormous economic value, due to the caused diseases on different tree plantations (e.g. G. boninense in oil palms) and the medicinal properties of certain species (e.g. G. applanatum, G. lingzhi and G. sinense). The cultivated Ganoderma strains used by Hungarian growers originate both from selected wild strains or more often taxonomically not evaluated isolates with uncertain origin. However, based on morphological characteristics, the species concepts in the genus lack consensus, and the taxonomy of many Ganoderma taxa is thus problematic. Therefore, in addition to the morphological examination, suitable molecular methods have recently been required to the taxonomically correct identification of the wild Ganoderma species and cultivated strains in many cases. DNA barcode is a widely accepted tool for species identification and authentication of commercial products containing Ganoderma species. Among the tested fungal DNA barcoding markers, the application of the internal transcribed spacer (ITS) is the most commonly used and it was formally proposed as the primary fungal barcode marker. Besides the ITS, several other DNA barcoding markers were used by different authors to clarify taxonomic difficulties in Ganoderma: e.g. β-tubulin, LSU, rpb1, rpb2, Tef1-α or the mtSSU rDNA sequence. Formerly, the Hungarian Ganoderma species (viz. G. adspersum, G. applanatum, G. carnosum, G. cupreolaccatum, G. lucidum and G. resinaceum) were briefly studied by Papp and Szabo (2013, in Acta Silv. Lign. Hung. 9: 71–83.), however, based on solely morphological charactersitics. In this study we aimed (i) to generate DNA barcoding sequences for all wild Ganoderma species observed in Hungary; furthermore, (ii) to investigate and evaluate the Hungarian cultivated strains labelled as “G. lucidum” and the Ganoderma spp. isolates preserved in culture collections, based on DNA barcoding sequence analysis. Supported by the UNKP-17-4 New National Excellence Program of the Ministry of Human Capacities.