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Sporothrix (Sordariales, Ascomycota) is a well-supported monophyletic lineage within the Ophiostomatales, species of which occur in a diverse range of habitats including on forest trees, in the soil, associated with bark beetles and mites as well as on the fruiting bodies of some Basidiomycota. Several species have also been reported as important human and animal pathogens. During surveys of insect- and wound-associated Ophiostomatales from hardwood trees in Poland, many isolates with affinity to Sporothrix were recovered. In the present study, six undescribed Sporothrix spp. collected during these surveys are characterized based on their morphological characteristics and multi-locus phylogenenetic inference. They are described as Sporothrix cavum, Sporothrix cracoviensis, S. cryptarchum, S. fraxini, S. resoviensis, and S. undulata. Two of the Sporothrix spp. reside in the S. gossypina-complex, while one forms part of the S. stenoceras-complex. One Sporothrix sp. is a member of lineage F, and two other species grouped outside any of the currently defined species complexes. All the newly described species were recovered from hardwood habitats in association with sub-cortical insects, wounds or woodpecker cavities. These species were morphologically similar, with predominantly asexual states having hyaline or lightly pigmented conidia, which produce holoblastically on denticulate conidiogenous cells. Five of the new taxa produce ascomata with necks terminating in long ostiolar hyphae and allantoid ascospores without sheaths. The results suggest that Sporothrix species are common members of the Ophiostomatales in hardwood ecosystems of Poland.

The genus Ceratocystiopsis (Ophiostomatales, Ascomycota) includes 21 species, which can be found mainly in association with bark beetles in the Northern Hemisphere. A survey of Ceratocystiopsis species associated with bark beetles infesting Picea abies and Pinus sylvestris in Norway yielded 126 isolates, representing Ceratocystiopsis neglecta and Ceratocystiopsis rollhanseniana, and four species described herein as Ceratocystiopsis chalcographii, Ceratocystiopsis debeeria, Ceratocystiopsis norroenii and Ceratocystiopsis troendelagii. The new taxa were morphologically characterised and phylogenetically analysed on the basis of sequence data of multiple loci (ITS, LSU, beta-tubulin (TUB2), calmodulin (CAL) and translation elongation factor 1-alpha (TEF1) genes). Ceratocystiopsis norroenii and C. rollhanseniana were the most frequently isolated species, and the latter species had the wider vector range.

During surveys of insect-associated mycobiomes in Norway, Poland, and Russia, isolates with affinity to Graphilbum (Ophiostomatales, Ascomycota) were recovered. In this study, eight known Graphilbum species as well as the newly collected isolates were compared based on morphology and DNA sequence data for four gene regions. The results revealed seven new species, described here as G. acuminatum, G. carpaticum, G. curvidentis, G. furuicola, G. gorcense, G. interstitiale, and G. sexdentatum. In addition to these species, G. crescericum and G. sparsum were commonly found in Norway. All new species were recovered from conifers in association with bark beetles, cerambycid beetles, and weevils and were morphologically similar, predominantly with pesotum-like asexual morphs. Where sexual morphs were present, these were small ascomata with short necks and rod-shaped ascospores having hyaline sheaths. The results suggest that Graphilbum species are common members of the Ophiostomatales in conifer ecosystems.

Blue stain is a type of discoloration that considerably lowers the aesthetic qualities of wood. During harvesting, fungal inoculum finds its way into the wood through places of cutting, delimbing, and damage to the tree stem. The development of peripheral blue stain in the logs of Scots pine (Pinus sylvestris L.) due to damage by a harvester head was investigated, using logs felled and delimbed with a chainsaw as reference. The development of blue stain was related to the age class of the stand, the date of felling, and the microclimatic conditions of the wood storage place. The mean surface area of blue stain in logs produced with the harvester was almost 35 cm2, approximately 30% larger than that of the reference logs. In stands of the fourth age class (diameter at breast height 32 cm), the surface of blue stain was more than two times larger than that of stands of the third age class (diameter at breast height 24 cm). The mean area of blue stain in wood stored after spring felling (19.3 cm2) was about 50% of that after summer felling (38.2 cm2). In particular, the development of blue stain in logs obtained with a harvester was visible between weeks 6 and 9 after spring felling and between weeks 3 and 6 after summer felling. For both felling dates, the range of blue stain depended less on air temperature around the wood stack and depended more on the duration of storage.

The genus Ceartocystiopsis includes ascomycetes fungi belonging to the Ophiostomatales that are not well recognized in the world. Described species so far have been found mainly in association with bark beetles in the Northern Hemisphere. The aims of this study were therefore to survey of distribution of species of Ceratocystiopsis associated with bark beetles infesting Picea abies and Pinus sylvestris in Norway. Adults for 22 different bark beetle species were collected from 13 stands in Norway. During this study, we recovered 126 isolates showing affinities to Ceratocystiopsis representing six species, including two described and four undescribed taxa. The four undescribed taxa collected during this work were characterised based on their morphological characteristics and multi-gene phylogenies. Herein, we describe these new species as Ceratocystiopsis chalcographii sp. nov., Ceratocystiopsis debeeria sp. nov., Ceratocystiopsis norroenii sp. nov. and Ceratocystiopsis troendelagii sp. nov. Ceratocystiopsis norroenii and C. rollhanseniana were the most frequently isolated species although the latter species had a much wider vector range. This study expands our knowledge about the taxonomy and species diversity of Ceratocystiopsis and beetle-fungus relationships.

Members of the genus Fusarium and related genera are important components of many ecosystems worldwide and are responsible for many plant diseases. However, the structure of beech litter-inhabiting Fusarium communities and their potential role in reducing the natural regeneration of European beech are not well understood. To address this issue, we examined Fusarium communities in the litter of uneven-aged, old-growth beech-dominated forests in the Carpathians (Poland) and in the Alps (Austria), and in a managed beech stand (Poland). The fungi inhabiting beech litter were investigated using beechnuts and pine seedlings as bait. The pathogenicity of the most common species was investigated by inoculating beech germinants. Fusarium spp. were identified based on morphology and DNA sequence comparisons of RPB2 and TEF1-α genes, combined with phylogenetic analyses. Twelve fungal species were identified from 402 isolates, including nine known and three currently undescribed species. The isolates resided in three species complexes within the genus Fusarium. These were the F. oxysporum (one taxon), F. sambucinum (three taxa), and F. tricinctum (six taxa) species complexes. In addition, one isolate was assigned to the genus Neocosmospora, and one isolate could be placed within the genus Fusicolla. The most frequently isolated fungi from beechnuts and beech germinants were F. avenaceum (Fr.) Sacc., F. sporotrichioides Sherb. and Fusarium sp. B. The structure and abundance of species within Fusarium communities varied by beech forest type. The species richness of Fusarium spp. was greatest in old-growth beech-dominated stands, while abundances of Fusarium spp. were higher in managed beech-dominated stands. Pathogenicity tests showed that all four Fusarium species isolated from beechnuts and beech germinants could cause germinants to rot beech, suggesting that these fungi may play a negative role in the natural beech regeneration.

Fungi in the orders Ophiostomatales and Microascales (Ascomycota), often designated as ophiostomatoid fungi, are frequent associates of scolytine bark and ambrosia beetles that colonize hardwood and coniferous trees. Several species, e.g., Ophiostoma novo-ulmi, are economically damaging pathogens of trees. Because little is known regarding the ophiostomatoid fungi in Europe, we have explored the diversity of these fungi associated with hardwood-infesting beetles in Poland. This study aims to clarify the associations between fungi in the genera Ambrosiella, Graphium (Microascales), Graphilbum, Leptographium, Ophiostoma and Sporothrix (Ophiostomatales) and their beetle vectors in hardwood ecosystems. Samples associated with 18 bark and ambrosia beetle species were collected from 11 stands in Poland. Fungi were isolated from adult beetles and galleries. Isolates were identified based on morphology, DNA sequence comparisons for five gene regions (ITS, LSU, sT, TEF 1-α, and CAL) and phylogenetic analyses. In total, 36 distinct taxa were identified, including 24 known and 12 currently unknown species. Several associations between fungi and bark and ambrosia beetles were recorded for the first time. In addition, associations between Dryocoetes alni, D. villosus, Hylesinus crenatus, Ernoporus tiliae, Pteleobius vittatus and ophiostomatoid fungi were reported for the first time, and Sporothrix eucastanea was reported for the first time outside of the USA. Among the species of Ophiostomatales, 14 species were in Ophiostoma s. l., two species were in Graphilbum, nine species were in Sporothrix, and seven species were in Leptographium s. l. Among the species of Microascales, three species were in Graphium, and one was in Ambrosiella. Twenty taxa were present on the beetles and in the galleries, twelve only on beetles, and four only in galleries. Bark and ambrosia beetles from hardwoods appear to be regular vectors, with ophiostomatoid fungi present in all the beetle species. Most ophiostomatoid species had a distinct level of vector/host specificity, although Ophiostoma quercus, the most frequently encountered species, also had the greatest range of beetle vectors and tree hosts. Plant pathogenic O. novo-ulmi was found mainly in association with elm-infesting bark beetles (Scolytus multistriatus, S. scolytus, and P. vittatus) and occasionally with H. crenatus on Fraxinus excelsior and with Scolytus intricatus on Quercus robur.

Ophiostoma spp. (Ophiostomatales, Ascomycota) are well-known fungi associated with bark and ambrosia beetles (Curculionidae: Scolytinae, Platypodinae). Fungi in the Ophiostomatales include serious tree pathogens as well as agents of timber blue-stain. Although these fungi have been extensively studied in the northern hemisphere, very little is known regarding their occurrence on hardwoods in Europe. The aims of the present study were to identify and characterize new Ophiostoma spp. associated with bark and ambrosia beetles infesting hardwoods in Norway and Poland, and to resolve phylogenetic relationships of Ophiostoma spp. related to the Norwegian and Polish isolates, using multigene phylogenetic analyses. Results obtained from five gene regions (ITS, LSU, β-tubulin, calmodulin, translation elongation factor 1-α) revealed four new Ophiostoma spp. These include Ophiostoma hylesinum sp. nov., O. signatum sp. nov., and O. villosum sp. nov. that phylogenetically are positioned within the Ophiostoma ulmi complex. The other new species, Ophiostoma pseudokarelicum sp. nov. reside along with Ophiostoma karelicum in a discrete, well-supported phylogenetic group in Ophiostoma s. stricto. The results of this study clearly show that the diversity and ecology of Ophiostoma spp. on hardwoods in Europe is poorly understood and that further studies are required to enrich our knowledge about these fungi.

Acidophilic fungi are characterized by their ability to tolerate very low pH conditions and to grow optimally below pH 5. The genus Acidiella (Dothideomycetes, Capnodiales, Teratosphaeriaceae) comprises acidophilic and acidotolerant fungi that are commonly distributed in highly acidic soils, drainages and waters worldwide. This study revises Acidiella taxonomy and provides alternative DNA barcodes. The morphological characteristics were revaluated by the investigation of conidial ontogeny, and knowledge of the ecology and biogeography of the genus is summarized. The new species Acidiella polonica isolated from highly acid (pH 2.7–3.8) technogenic soil developed on mine spoils in Poland is described here. This species is distinguishable by genetic markers, morphology and its ability to grow at pH 1. Based on DNA sequence and morphological comparisons, we also show that Acidiella uranophila (syn. Fodinomyces uranophilus) is a synonym of Acidiella bohemica. Among all species, A. bohemica is the most commonly isolated and is widely distributed over four continents. Interestingly, its distribution at the global scale is limited to extremely acidic substrates (pH

Geosmithia species (Hypocreales, Ascomycota) are associates of bark beetles and other arthropods. One species, Geosmithia morbida, is a virulent tree pathogen of Juglans nigra. To date, 10 Geosmithia spp. from conifer-infesting, and at least 23 species from hardwood associated bark beetles have been reported from Europe. The aim of this study was to survey Geosmithia spp. associated with 18 bark and ambrosia beetle species in hardwood ecosystems in Poland. In addition, we evaluated the pathogenicity of the six Geosmithia species by inoculating Acer, Fagus, Quercus, Tilia and Ulmus seedlings. Our surveys yielded a total of 1060 isolates from 2915 beetles and 1887 galleries. We identified isolates using morphology and ITS, β-tubulin and TEF1-α sequences. Altogether we identified 11 species including nine previously known and two new species described here as Geosmithia fagi sp. nov. and G. pazoutovae sp. nov. In addition, a sister species G. longistipitata sp. nov., associated with Picea trees, is described here. Bark beetles from hardwoods, with exeption of Dryocoetes alni, D. villosus, Scolytus ratzeburgi and ambrosia beetles, appear to be regular vectors of Geosmithia spp. Like in other parts of the world, most Geosmithia taxa exhibited a distinct level of vector/host specificity. None of Geosmithia isolates induced any disease symptoms under the conditions of our experiment. This study highlights the need for more intensive surveys across additional areas of Central and Northern Europe, insect vectors and host tree species in order to elucidate the Geosmithia species diversity in this region.

The physiological and behavioural activities of animals have far-reaching impacts on the characteristics and functioning of soil. This includes vertebrates, which are capable of modifying the physicochemical and biochemical properties of soil. To date, however, no species is known to be responsible for the entire process of soil formation, modification and maintenance. Large-bodied birds build nests which they then use for several years or even decades. During nest construction or renovation, birds gather and transport to the nesting site organic and mineral matter that includes tree branches of various sizes, twigs, turf, straw and hay. Over time, during subsequent breeding events, adult birds supply further loads of organic matter to the nest, such as food remains, excrement, pellets, feathers, egg shells and other materials. Taking the White Stork Ciconia ciconia as an example, we have shown that the materials deposited in the nests of large-bodied birds gradually produce ornithogenic soils over the years, with distinguishable layers having different physicochemical characteristics and biochemical activities. The tested nesting substrate met the criteria for ornithogenic material; the layers had appropriate thickness and phosphorus pentoxide (P2O5) content. Results of the study indicates that the material contained in White Stork nests have the characteristics of Histosols. Moreover, such nests harbour assemblages of fungi and arthropods that contain species typical of soil mycobiota and fauna, respectively. This study is the first to describe a soil that is formed, modified and maintained entirely by vertebrates and is physically isolated from the ground. Our results highlight the fact that the nests of large birds are unique structures in ecosystems and provide a habitat for a rich and diverse assemblage of organisms.

During surveys of insect-associated mycobiomes in Norway, Poland, and Russia, isolates with affinity to

Bark beetles belonging to the genus Dryocoetes (Coleoptera, Curculionidae, Scolytinae) are known vectors of fungi, such as the pathogenic species Grosmannia dryocoetidis involved in alpine fir (Abies lasiocarpa) mortality. Associations between hardwood-infesting Dryocoetes species and fungi in Europe have received very little research attention. Ectosymbiotic fungi residing in Ceratocystiopsis and Leptographium (Ophiostomatales, Sordariomycetes, Ascomycota) were commonly detected in previous surveys of the Dryocoetes alni-associated mycobiome in Poland. The aim of this study was to accurately identify these isolates and to provide descriptions of the new species. The identification was conducted based on morphology and DNA sequence data for six loci (ITS1-5.8S, ITS2-28S, ACT, CAL, TUB2, and TEF1-α). This revealed two new species, described here as Ceratocystiopsis synnematasp. nov. and Leptographium alneumsp. nov. The host trees for the new species included Alnus incana and Populus tremula. Ceratocystiopsis synnemata can be distinguished from its closely related species, C. pallidobrunnea, based on conidia morphology and conidiophores that aggregate in loosely arranged synnemata. Leptographium alneum is closely related to Grosmannia crassivaginata and differs from this species in having a larger ascomatal neck, and the presence of larger club-shaped cells.

Species of Leptographium are characterized by mononematous or synnematous conidiophores and are commonly associated with different arthropods. Some of them also produce a sexual state characterised by globose ascomata with elongated necks. Compared to investigations on coniferous trees, the occurrence of Leptographium species on hardwood trees has been poorly studied in Europe. During a survey of ophiostomatoid fungi on various hardwood tree species in Norway and Poland, three unusual species, which fit in the broader morphological description of Leptographium spp., were found in association with Trypodendron domesticum, Trypodendron signatum and Dryocoetes alni, and from wounds on a variety of hardwoods. Phylogenetic analyses of sequence data for six different loci (ITS1–5.8 S–ITS2, ITS2-LSU, ACT, β-tubulin, CAL, and TEF-1α) showed that these Leptographium species are phylogenetically closely related to the species of the Grosmannia olivacea complex. The first species forms a well-supported lineage that includes Ophiostoma brevicolle, while the two other new taxa resided in a separate lineage; possibly affiliated with Grosmannia francke-grosmanniae. All the new species produce perithecia with necks terminating in ostiolar hyphae and orange-section shaped ascospores with cucullate, gelatinous sheaths. These species also produce dark olivaceous mononematous asexual states in culture. In addition, two of the newly described species have a second type of conidiophore with a short and non-pigmented stipe. The new Leptographium species can be easily distinguished from each other by their appearance and growth in culture. Based on novel morphological characters and distinct DNA sequences, these fungi were recognised as new taxa for which the names Leptographium tardum sp. nov., Leptographium vulnerum sp. nov., and Leptographium flavum sp. nov. are provided. Electronic supplementary material The online version of this article (10.1007/s10482-018-1123-8) contains supplementary material, which is available to authorized users.

Relict charcoal hearths (RCHs) increases soil fertility in forest ecosystems. However, the effects of RCHs on the activity and abundance of soil microorganisms remain unknown. In this paper, we analysed the impact of relict charcoal production on the soil enzymatic activity and composition of soil bacterial and fungal communities in Scots pine forests of the Manowo Forest District in northern Poland. Moreover, we determined the effect of relict charcoal production on the soil properties. Our research was conducted by comparing the physical, chemical, enzymatic and microbiological properties of charcoal-enriched and charcoal-free soils. Significant differences in physical properties were found between these two soil types in terms of their structure and water holding capacity. As expected, horizons enriched with charcoal were characterised by a significantly higher organic carbon content (4.7% on average compared to 2.2% in control horizons), and also by a considerably higher content of available phosphorus (an average of 64.07 mg·kg−1 compared to 36.21 mg·kg−1 in the control). Similarly, RCH horizons displayed a higher pH and higher contents of Ca and Na cations. These results indicated that RCH soils provided more favourable conditions for the soil microbiome, as reflected by the higher enzymatic activity and diversity of the microorganisms. Moreover, bacterial and fungal communities in RCH soils were more diverse and had greater species/genera richness, especially in the case of fungi. Members of the genus Rhodoplanes dominated the bacterial community at both RCH and non-RCH sites, followed by Streptomyces, Burkholderia, Skermanella, Tsukamurella and Candidatus Solibacter. Both culture- and next generation sequencing (NGS)-based analyses showed that soil fungal communities were dominated by Ascomycota, with Penicillium as the most abundant genus. Our results showed that hearth soils may represent a significant C pool in the forest ecosystem. This study supports the strategy of safeguarding such charcoal-enriched soils as precious C reservoirs and ecologically important biodiversity hotspots. Moreover, the application of charcoal may effectively increase the microbial diversity of forest soils, especially during the reforestation or re-cultivation of disturbed habitats.

Dieback of young Abies alba seedlings was identified as an important limitation for natural regeneration of this species in the mountain regions of Central Europe. Approximately 2–4 weeks after emergence, during cool and wet weather, necrotic spots developed on seedling cotyledons. Later they expanded and merged to finally cover all above-ground tissues. Symptomatic seedlings of A. alba were sampled at 16 stands, and fungi were isolated from the cotyledons, stems, and roots. Morphological and molecular methods based on ITS rDNA sequencing were then used for isolate identification. In total, 105 distinct taxa were identified, with Ascomycota dominating, representing 97.4% of the isolates. The most frequently isolated taxa were Allantophomopsis lycopodina, Gyoerffyella rotula, Leptosphaeria sp., Phialocephala fortinii, Pseudaegerita sp., Scirrhia aspidiorum, Sydowia polyspora, Peyronellaea sp., Phomopsis sp., and Varicosporium elodeae. The frequency of colonization by individual fungal species differed among the three plant organs and among forest types. In symptomatic cotyledons, the dominant species were G. rotula, S. polyspora, and Pseudaegerita sp. whose pathogenicity, together with that of Gyoerffyella sp., V. elodeae, and Hormonema carpetanum, was tested on young A. alba seedlings. Only G. rotula and Gyoerffyella sp. caused serious dieback of above-ground seedling tissues and necrotic symptoms on cotyledons. This study is one of the few comprehensive reports showing that aquatic hyphomycetes commonly occur in forests beyond their preferred habitat.

Globally, tree-holes are important ecological component of forest and woodlands. Numerous microorganisms rely on cavities, both natural and those excavated by primary cavity nesting birds, mainly by woodpeckers, for their survival and reproduction. However, the fungi occurring in cavities are not well characterized. Specifically, very little is known about the fungal communities inhabiting the woodpecker nest cavities. Therefore, in this study, we investigated the fungal diversity of cavities in southern Poland. The samples were collected from freshly excavated woodpecker nest cavities using a nondestructive method (ND). The spatial distribution of fungal communities within the cavities was evaluated by sampling different parts of a single cavity using a destructive method (D). We detected 598 fungal isolates that included 64 species in three phyla and 16 orders using the ND method. Most of the fungi isolated from the cavities represented the phylum Ascomycota (73.9% of the isolates) with 11 orders, and Microascales was the predominant order (30% of the isolates). The most common species detected was Petriella musispora, which was isolated from 65% of the cavities. A total of 150 isolates (25%) were members of Basidiomycota, with Hymenochaetales being the dominant order (16% of the isolates). The basidiomycetous fungi were isolated from 55% of the cavities. Several taxa closely related to the pathogenic fungi and associated with secondary animal infections were detected in the wood of cavities. We identified different fungal communities in the three cavity parts using the D method. The cavity entrance had more number of species than the middle and bottom parts. The results of this study advanced our current knowledge on the mycobiota in woodpecker nest cavities and provided preliminary evidence for tree cavities being the hotspot for fungal diversity.

Summary Cylindrocarpon-like fungi are globally distributed plant pathogens and have a wide range of host species. However, very little is known about the species that live in the topsoil of forests and their potential role in reducing the natural regeneration of tree species, particularly of forest trees that produce abundant fruit only once every few years. To enhance our understanding of the species that inhabit the topsoil, we studied the diversity and pathogenicity of Cylindrocarpon-like fungi inhabiting the litter in old-growth mixed-beech forests in the Carpathians (Poland) and in the Alps (Austria), and in a managed beech stand in the Krakowsko-Czestochowska Highland (Poland). The fungi inhabiting the beech litter were investigated using beechnuts and pine seedlings as bait. Isolates were identified based on morphology and DNA sequencing. The pathogenicity of the most common species was investigated by inoculating beech germinants. A wide range of Cylindrocarpon-like fungi were associated with the beech litter: 718 cultures representing 12 species were isolated. Five taxa were identified down to species level: namely Ilyonectria crassa, I. pseudodestructans, I. rufa, Neonectria candida and N. obtusispora, and seven species were identified to genus level (Neonectria or Ilyonectria species). Ilyonectria destructans, which is considered to be the sexual morph of ‘Cylindrocarpon destructans’, was not found. There were qualitative and quantitative differences between the different forest sites in terms of Neonectria and Ilyonectria species composition in beech litter. The isolation frequency and species richness of Cylindrocarpon-like fungi were greatest in beech litter taken from old-growth mixed-beech forests. Neonectria and Ilyonectria species were capable of killing beech germinants, suggesting that they may play a negative role in natural beech regeneration.

Fungi under the order Ophiostomatales (Ascomycota) are known to associate with various species of bark beetles (Coleoptera: Curculionidae: Scolytinae). In addition this group of fungi contains many taxa that can impart blue-stain on sapwood and some are important tree pathogens. A recent survey that focussed on the diversity of the Ophiostomatales in the forest ecosystems of the Czech Republic and Poland uncovered four putative new species. Phylogenetic analyses of four gene regions (ITS1-5.8S-ITS2 region, ß-tubulin, calmodulin, and translation elongation factor 1-α) indicated that these four species are members of the genus Ophiostoma. All four newly described species can be distinguished from each other and from closely related species based on DNA sequence comparisons, morphological characters, growth rates, and their insect associations. Based on this study four new taxa can be circumscribed and the following names are provided: Ophiostoma pityokteinis sp. nov., Ophiostoma rufum sp. nov., Ophiostoma solheimii sp. nov., and Ophiostoma taphrorychi sp. nov. O. rufum sp. nov. is a member of the Ophiostoma piceae species complex, while O. pityokteinis sp. nov. resides in a discrete lineage within Ophiostoma s. stricto. O. taphrorychi sp. nov. together with O. distortum formed a well-supported clade in Ophiostoma s. stricto close to O. pityokteinis sp. nov. O. solheimii sp. nov. groups within a currently undefined lineage A, which also includes Ophiostoma grandicarpum and Ophiostoma microsporum. This study highlights the need for more intensive surveys that should include additional countries of Central Europe, insect vectors and host tree species in order to elucidate Ophiostoma species diversity in this region. Electronic supplementary material The online version of this article (10.1007/s10482-019-01277-5) contains supplementary material, which is available to authorized users.

Ophiostoma quercus (Ascomycota, Ophiostomatales) is a globally widespread, insect-vectored fungus that colonizes a wide diversity of hardwood and conifer hosts. Although the fungus is considered to be non-pathogenic, it is closely related to the fungi that cause Dutch elm disease. We examined the global diversity of O. quercus based on a ribosomal RNA marker and three unlinked gene regions. The fungus exhibited substantial morphological diversity. In addition, O. quercus had high genetic diversity in every continent from which it was collected, although the fungus was most diverse in Eurasia. There was no evidence of geographical clustering of haplotypes based on phylogenetic and network analyses. In addition, the phylogenetic trees generated based on the different markers were non-congruent. These results suggest that O. quercus has been repeatedly moved around the globe, because of trade in wood products, and that the fungal species most likely outcrosses regularly. The high genetic diversity of the fungus, as well as its ability to utilize a wide variety of arthropod vectors and colonize a tremendous diversity of tree host species makes O. quercus truly unique among ophiostomatoid fungi.

Species of Leptographium are generally characterized by mononematous conidiophores and are commonly associated with bark beetles and weevils. These species are responsible for sapstain and in some cases serious diseases on a range of primarily coniferous trees. In comparison with coniferous trees, the occurrence of Leptographium species on hardwood trees has been poorly studied in Europe. During a survey of ophiostomatoid fungi on various tree species in Norway and Poland, three unusual species, which fit the broader morphological description of Leptographium spp., were found in association with Scolytus ratzeburgi, Dryocoetes alni and Trypodendron domesticum on a variety of hardwoods, and from wounds on Tilia cordata. Phylogenetic analyses of sequence data for three gene regions (ITS2-LSU, β-tubulin, and TEF1-α) showed that these Leptographium species are phylogenetically closely related to each other and form a well-supported lineage that included Grosmannia grandifoliae and Leptographium pruni. The first species could be distinguished from the other Leptographium species based on conidiophores arising from spiral hyphae, chlamydospore-like structures and a hyalorhinocladiella-like synanamorph in culture. The second species differs from the previous one by having distinctly shorter conidiophores and smaller conidia. This species also produces a well-developed sporothrix-like synanamorph with denticulate conidiogenous cells. Based on these unusual morphological characteristics and distinct DNA sequences, these fungi were recognised as new taxa for which the names Leptographium trypodendri sp. nov. and L. betulae sp. nov. are provided. The third group of isolates belonged to Grosmannia grandifoliae, representing the first report of this species outside of the USA. The newly defined G. grandifoliae complex is the first species complex in Leptographium s.l. consisting of only hardwood-infecting species.

Bark beetles (Coleoptera, Scolytinae) are known to be associated with fungi, particularly species of the orders Ophiostomatales and Microascales. However, very little is known about other ectosymbionts of phloeophagous bark beetles on Pinaceae. In this study, we examined the Geosmithia species associated with eight bark beetle species infesting Picea abies and Pinus sylvestris branches in Poland. Fungi were isolated from 1 731 samples collected from 14 study sites. We identified a total of 653 isolates that were sorted into nine taxa based on their phenotypic similarity and phylogeny of their ITS-LSU regions of rDNA, β-tubulin, elongation factor 1α and the second-largest subunit of the RNA polymerase II gene. They represented nine species without formal names. There were large quantitative and qualitative differences in the composition of Geosmithia communities between P. sylvestris and P. abies trees. The proportion of samples infested with Geosmithia species suggests that this association is more widespread among bark beetles infesting branches of P. sylvestris . In addition, these beetles were vectors of different Geosmithia species compared with than the beetles that colonize P. abies . In mixed-conifer forests, the Geosmithia communities were more diverse and richer than in pure spruce or pine stands, where the insects Pityogenes chalcographus and Pityophthorus pityographus with low host-specificity play a distributing role for various Geosmithia species. Among eight bark beetle species examined, only P. bidentatus , P. pityographus , P. chalcographus and Polygraphus poligraphus acted as effective vectors for Geosmithia species. The following hypothesis emerges from these studies: changes in the composition of ectosymbionts of pine- and spruce-infesting bark beetles in Central Europe run along a gradient of thickness of the wood substrata preferred by insects.

Ophiostomatoid fungi are known to be associated with Tomicus spp. on Pinus sylvestris. However, very little is actually known about the fungi present in the pine shoots damaged by these insects. The aim of this study was to survey species of Ophiostoma s.lato associated with fallen shoots of Scots pine pruned by Tomicus spp. in Poland. The study was conducted in four pure Scots pine stands in southern and south-western part of the country. Fungi were identified based on morphology and DNA sequence comparison for two gene (the ITS rDNA region and ß–tubulin). In total, 64 isolates obtained, represent seven species of ophiostomatoid fungi, including their asexual states of the genera. Two of them, Ophiostoma sp. 1 and Sporothrix sp. 1 probably represent new taxa. All species were found at very low frequencies. Among them, Ophiostoma minus, Ophiostoma sp. 1 and Sporothrix sp. 1 were the most frequently isolated, with a frequency of 2.0%. Occasionally, isolated species included Leptographium piriforme, Ophiostoma canum, Ophiostoma floccosum and Grosmannia cucullata-like. Association of species of Ophiostoma s. lato with Tomicus spp. and the taxonomic status of two new species are discussed.

Fungi from the genus Geosmithia (Ascomycota: Hypocreales) are associated with bark beetles (Coleoptera: Scolytinae), though little is known about ecology, diversity, and distribution of these fungi across beetle and its host tree species. This study surveyed the diversity, distribution and vector affinity of Geosmithia isolated from subcortical insects that colonized trees from the family Pinaceae in Central and Northeastern Europe. Twelve Geosmithia species were isolated from 85 plant samples associated with 23 subcortical insect species (including 14 bark beetle species). Geosmithia community composition was similar across different localities and vector species; although the fungal communities associated with insects that colonized Pinus differed from that colonizing other tree species (Abies, Larix, and Picea). Ten Geosmithia species from four independent phylogenetic lineages were not reported previously from vectors feeding on other plant families and seem to be restricted to the vectors from Pinaceae only. We conclude that presence of such substrate specificity suggests a long and stable association between Geosmithia and bark beetles.

Bark weevils are consistently associated with various fungi. They act as effective vectors for root-rot fungi, the rust pathogen and the ophiostomatoid fungi. In comparison with bark beetles, the interaction between ophiostomatoid fungi and bark weevils has been poorly studied in Europe. This study aims to clarify the ties among ophiostomatoid fungi and their weevil vectors in Pinus sylvestris. Samples associated with three bark weevils, including Pissodes castaneus, P. piniphilus and P. pini were collected from seven pine stands in Poland. Fungi were isolated from laboratory-reared and field-collected beetles, larvae and galleries of weevils. Isolates were identified based on morphology, DNA sequence comparison for two gene regions (ITS, s-tubulin) and phylogenetic analyses. Fourteen morphological and phylogenetic ophiostomatoid species were identified among the 1,219 isolates. These 14 species included 11 novel associations between fungi and bark weevils. The most commonly encountered fungal associates of bark Pissodes species were Leptographium procerum, Ophiostoma quercus and O. minus. The spectrum of fungal associates was similar in three bark weevil species, despite some differences between species. Except for P. castaneus, all species of bark weevil were frequently associated with ophiostomatoid fungi. Pissodes castaneus does appear to be a consistent vector of L. procerum and Sporothrix inflata while O. minus, O. quercus and O. cf. rectangulosporium were often found in association with P. piniphilus and P. pini.

Bark beetles are known to be associated with fungi, especially the ophiostomatoid fungi. However, very little is known about role of pine weevils, e.g., Hylobius abietis, as a vector of these fungi in Europe. The aims of our study were to demonstrate the effectiveness of H. abietis as a vector of ophiostomatoid fungi in Poland and to identify these fungi in Scots pine seedlings damaged by weevil maturation feeding. Insects and damaged Scots pine seedlings were collected from 21 reforestation sites in Poland. The fungi were identified based on morphology, DNA sequence comparisons for two gene regions (ITS, β-tubulin) and phylogenetic analyses. Sixteen of the ophiostomatoid species were isolated and identified. In all insect populations, Leptographium procerum was the most commonly isolated fungus (84 %). Ophiostoma quercus was also found at a relatively high frequency (16 %). Other ophiostomatoid fungi were found only rarely. Among these rarer fungi, four species, Leptographium lundbergii, Ophiostoma floccosum, Ophiostoma piliferum and Sporothrix inflata, were isolated above 3 %. L. procerum was isolated most frequently and was found in 88 % of the damaged seedlings. S. inflata was isolated from 26 %, while O. quercus occurred in 10 % of the seedlings. This study confirmed that L. procerum and O. quercus were common associates of H. abietis, while others species were found inconsistently and in low numbers, indicating causal associations. H. abietis also acted as an effective vector transmitting ophiostomatoid species, especially L. procerum and S. inflata, to Scots pine seedlings.

Appropriate management of invasive fungi requires adequate understanding of their global diversities and movement histories. The fungus Leptographium procerum is associated with root-colonizing forest insects in pine forests throughout the world, and may have contributed to the aggressive behaviour of the red turpentine beetle (Dendroctonus valens) in the beetle's invasive range in China. We used microsatellites and mating type loci to investigate the global diversity of L. procerum and the source population of L. procerum associated with D. valens in China. Clustering analyses supported the separation of the fungal data set into three genetically and geographically-distinct clusters: Europe, North America, and China. The fungus had the highest genetic diversity in Europe, followed by North America and China. Analyses using Approximate Bayesian Computation supported Europe as the most likely source of the North American and Chinese populations. Overall, the results suggested that Europe is the global centre of diversity of L. procerum. Furthermore, they suggested that L. procerum most likely arrived in China independently of D. valens and adopted this beetle as a vector after its introduction.