Ecological, morphological and phylogenetic survey of Fomes fomentarius and F. inzengae (Agaricomycetes, Polyporaceae) co-occurring in the same geographic area in Central Europe

Abstract The phenomenon of cryptic species is widespread among various fungal lineages. Fomes inzengae (Ces. & De Not.) Cooke has been recently recognized as a South European kin of wood-decay basidiomycete F. fomentarius (L.) Fr. due to the problematic morphological identification of both species, their taxonomic status has been disputed. The aim of this research is to examine the distribution, host preferences, morphological characters, and phylogenetic relationships between F. fomentarius and F. inzengae in the South Moravian region in Czechia (Central Europe), where both species occur sympatrically. The results revealed the ecological preferences of Fomes spp. along an altitudinal gradient, while F. inzengae is a lowland taxon, F. fomentarius dominates at higher altitudes in forests with abundant Fagus sylvatica . The main contact zone of the two taxa is located in the upper-colline vegetation belt (elevation ca. 400‒550 m a.s.l.). The morphological analysis revealed that the basidiospore size, the width of skeletal hyphae in basidiomes, and the linear density of pores of both taxa are almost identical and can not be used for the identification of the two species. Multigene sequence analyses of ITS, LSU, RPB1, RPB2, and TEF1 markers confirmed that F. fomentarius and F. inzengae are phylogenetically distinct species. The relationship of F. inzengae and F. fomentarius to Globifomes graveolens and Hexagonia spp. is discussed.