Core Ericaceae produce delicate hair roots with inflated rhizodermal cells that host plethora of fungal symbionts. These poorly known mycobionts include various endophytes, parasites, saprobes, and the ericoid mycorrhizal (ErM) fungi (ErMF) that form the ErM symbiosis crucial for the fitness of their hosts. Using microscopy and high-throughput sequencing, we investigated their structural and molecular diversity in 14 different host × site combinations in Northern Bohemia (Central Europe) and Argentine Patagonia (South America). While we found typical ericoid mycorrhiza in all combinations, we did not detect ectomycorrhiza and arbuscular mycorrhiza. Superficial mantles of various thickness formed by non-clamped hyphae were observed in all combinations except Calluna vulgaris from N. Bohemia. Some samples contained frequent intercellular hyphae while others possessed previously unreported intracellular haustoria-like structures linked with intracellular hyphal coils. The 711 detected fungal OTU were dominated by Ascomycota (563) and Basidiomycota (119), followed by four other phyla. Ascomycetes comprised Helotiales (255), Pleosporales (53), Chaetothyriales (42), and other 19 orders, while basidiomycetes Sebacinales (42), Agaricales (28), Auriculariales (7), and other 14 orders. While many dominant OTU from both hemispheres lacked close relatives in reference databases, many were very similar to identical to unnamed sequences from around the world. On the other hand, several significant ericaceous mycobionts were absent in our dataset, incl. Cairneyella, Gamarada, Kurtia, Lachnum, and Leohumicola. Most of the detected OTU could not be reliably linked to a particular trophic mode, and only two could be reliably assigned to the archetypal ErMF Hyaloscypha hepaticicola. Probable ErMF comprised Hyaloscypha variabilis and Oidiodendron maius, both detected only in N. Bohemia. Possible ErMF comprised sebacinoid fungi and several unnamed members of Hyaloscypha s. str. While H. hepaticicola was dominant only in C. vulgaris, this model ErM host lacked O. maius and sebacinoid mycobionts. Hyaloscypha hepaticicola was absent in two and very rare in six combinations from Patagonia. Nine OTU represented dark septate endophytes from the Phialocephala fortinii s. lat.-Acephala applanata species complex, including the most abundant OTU (the only detected in all combinations). Statistical analyses revealed marked differences between N. Bohemia and Patagonia, but also within Patagonia, due to the unique community detected in a Valdivian temperate rainforest. Our results show that the ericaceous hair roots may host diverse mycobionts with mostly unknown functions and indicate that many novel ErMF lineages await discovery. Transhemispheric differences (thousands of km) in their communities may be evenly matched by local differences (scales of km, m, and less).

• Klíčová slova
• Central Europe, Ericoid mycorrhizal fungi, Fungal root endophytes, Helotiales, Hyaloscypha sp., Oidiodendron maius, Root-associated fungi, Sebacinales, South America,
• MeSH
• Ascomycota MeSH
• Basidiomycota * MeSH
• endofyty genetika   MeSH
• Ericaceae * mikrobiologie   MeSH
• kořeny rostlin mikrobiologie   MeSH
• mykorhiza * genetika   MeSH
• symbióza MeSH
• Publikační typ
• časopisecké články MeSH

Data mining for a phylogenetic study including the prominent ericoid mycorrhizal fungus Rhizoscyphus ericae revealed nearly identical ITS sequences of the bryophilous Hyaloscypha hepaticicola suggesting they are conspecific. Additional genetic markers and a broader taxonomic sampling furthermore suggested that the sexual Hyaloscypha and the asexual Meliniomyces may be congeneric. In order to further elucidate these issues, type strains of all species traditionally treated as members of the Rhizoscyphus ericae aggregate (REA) and related taxa were subjected to phylogenetic analyses based on ITS, nrLSU, mtSSU, and rpb2 markers to produce comparable datasets while an in vitro re-synthesis experiment was conducted to examine the root-symbiotic potential of H. hepaticicola in the Ericaceae. Phylogenetic evidence demonstrates that sterile root-associated Meliniomyces, sexual Hyaloscypha and Rhizoscyphus, based on R. ericae, are indeed congeneric. To this monophylum also belongs the phialidic dematiaceous hyphomycetes Cadophora finlandica and Chloridium paucisporum. We provide a taxonomic revision of the REA; Meliniomyces and Rhizoscyphus are reduced to synonymy under Hyaloscypha. Pseudaegerita, typified by P. corticalis, an asexual morph of H. spiralis which is a core member of Hyaloscypha, is also transferred to the synonymy of the latter genus. Hyaloscypha melinii is introduced as a new root-symbiotic species from Central Europe. Cadophora finlandica and C. paucisporum are confirmed conspecific, and four new combinations in Hyaloscypha are proposed. Based on phylogenetic analyses, some sexually reproducing species can be attributed to their asexual counterparts for the first time whereas the majority is so far known only in the sexual or asexual state. Hyaloscypha bicolor sporulating in vitro is reported for the first time. Surprisingly, the mycological and mycorrhizal sides of the same coin have never been formally associated, mainly because the sexual and asexual morphs of these fungi have been studied in isolation by different research communities. Evaluating all these aspects allowed us to stabilize the taxonomy of a widespread and ecologically well-studied group of root-associated fungi and to link their various life-styles including saprobes, bryophilous fungi, root endophytes as well as fungi forming ericoid mycorrhizae and ectomycorrhizae.

• Klíčová slova
• Ectomycorrhiza, Ericoid mycorrhiza, Hyaloscypha bicolor (Hambl. & Sigler) Vohník, Fehrer & Réblová, Hyaloscypha finlandica (C.J.K. Wang & H.E. Wilcox) Vohník, Fehrer & Réblová, Hyaloscypha hepaticicola, Hyaloscypha melinii Vohník, Fehrer & Réblová, Hyaloscypha variabilis (Hambl. & Sigler) Vohník, Fehrer & Réblová, Hyaloscypha vraolstadiae (Hambl. & Sigler) Vohník, Fehrer & Réblová, Hymenoscyphus ericae, Meliniomyces, Molecular systematics, Mycorrhizal synthesis, Pezoloma ericae, Pseudaegerita, Sexual-asexual connection,
• Publikační typ
• časopisecké články MeSH