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Abstract Background In Europe, Pinus cembra forests cover subalpine and alpine areas and they are of high conservational and ecological relevance. These forests experience strong seasonality with alternating snow-free and snow covered periods. Although P. cembra is known for mycorrhization and mycorrhizae usually involve fungi, plants and bacteria, the community compositions of fungi and bacteria and their associations in (sub-)alpine P. cembra forests remain vastly understudied. Here, we studied the fungal and bacterial community compositions in three independent (sub-)alpine P. cembra forests and inferred their microbial associations using marker gene sequencing and network analysis. We asked about the effect of snow cover on microbial compositions and associations. In addition, we propose inferring microbial associations across a range of filtering criteria, based on which we infer well justified, concrete microbial associations with high potential for ecological relevance that are typical for P. cembra forests and depending on snow cover. Results The overall fungal and bacterial community structure was comparable with regards to both forest locations and snow cover. However, occurrence, abundance, and diversity patterns of several microbial taxa typical for P. cembra forests differed among snow-free and snow covered soils, e.g. Russula, Tetracladium and Phenoliphera. Moreover, network properties and microbial associations were influenced by snow cover. Here, we present concrete microbial associations on genus and species level that were repeatedly found across microbial networks, thereby confirming their ecological relevance. Most importantly, ectomycorrhizal fungi, such as Basidioascus, Pseudotomentella and Rhizopogon, as well as saprobic Mortierella changed their bacterial association partners depending on snow cover. Conclusion This is the first study researching fungal-bacterial associations across several (sub-)alpine P. cembra forests. The poorly investigated influence of snow cover on soil fungi and bacteria, especially those mycorrhizing P. cembra roots, but also saprobic soil organisms, underlines the relevance of forest seasonality. Our findings highlight that the seasonal impact of snow cover has significant consequences for the ecology of the ecosystem, particularly in relation to mycorrhization and nutrient cycling. It is imperative to consider such effects for a comprehensive understanding of the functioning resilience and responsiveness of an ecosystem.

Abstract Volatile organic compounds (VOCs) might mediate microbial interactions, especially in spatially structured environments, such as soil. However, the variety and specificity of VOC production are poorly understood. Here, we studied 25 Mortierellaceae strains belonging to the genera Linnemannia and Entomortierella in both pure and co-culture with Pseudomonas helmanticensis under laboratory conditions. We analysed both the fungal growth depending on co-cultivation and the cultures’ volatilomes applying proton-transfer-reaction time-of-flight and gas chromatography-mass spectrometry (PTR-ToF-MS and GC–MS). In a strain-specific manner, we found the fungi’s radial growth rate and colony morphology affected by the presence of P. helmanticensis. The fungus seemed to generally reduce the bacterial growth. The volatilomes of the fungal and bacterial pure and co-cultures were diverse. While the fungi frequently consumed VOCs, P. helmanticensis produced a higher diversity and amount of VOCs than any fungal strain. Our results support that both the pure and co-culture volatilomes are taxonomically conserved. Taken together, our data supports the relevance of VOCs in Mortierellaceae-P. helmanticensis interaction. We also discuss individual VOCs that appear relevant in the interaction.

Abstract Pigments of fungi are a fertile ground of inspiration: they spread across various chemical backbones, absorption ranges, and bioactivities. However, basidiomycetes with strikingly colored fruiting bodies have never been explored as agents for photodynamic therapy (PDT), even though known photoactive compound classes (e.g., anthraquinones or alkaloids) are used as chemotaxonomic markers. In this study, we tested the hypothesis that the dyes of skin-heads (dermocyboid Cortinarii) can produce singlet oxygen under irradiation and thus are natural photosensitizers. Three photosensitizers based on anthraquinone structures were isolated and photopharmaceutical tests were conducted. For one of the three, i.e., (–)-7,7′-biphyscion (1), a promising photoyield and photocytotoxicity of EC50 = 0.064 µM against cancer cells (A549) was found under blue light irradiation (λexc = 468 nm, 9.3 J/cm2). The results of molecular biological methods, e.g., a viability assay and a cell cycle analysis, demonstrated the harmlessness of 1 in the dark and highlighted the apoptosis-inducing PDT potential under blue light irradiation. These results demonstrate for the first time that pigments of dermocyboid Cortinarii possess a so far undescribed activity, i.e., photoactivity, with significant potential for the field of PDT. The dimeric anthraquinone (–)-7,7′-biphyscion (1) was identified as a promising natural photosensitizer.

Antimicrobial resistance is one of the biggest health and subsequent economic threat humanity faces. Next to massive global awareness campaigns, governments and NGOs alike stress the need for new innovative strategies to treat microbial infections. One of such innovative strategies is the photodynamic antimicrobial chemotherapy (PACT) in which the synergistic effects of photons and drugs are exploited. While many promising reports are available, PACT – and especially the drug-design part behind – is still in its infancy. Common best-practice rules, such as the EUCAST or CLSI protocols for classic antibiotics as well as high-throughput screenings, are missing, and this, in turn, hampers the identification of hit structures. Hit-like structures might come from synthetic approaches or from natural sources. They are identified via activity-guided synthesis or isolation strategies. As source for new antimicrobials, fungi are highly ranked. They share the same ecological niche with many other microbes and consequently established chemical strategies to combat with the others. Recently, in members of the Cortinariaceae, especially of the subgenus Dermocybe, photoactive metabolites were detected. To study their putative photoantimicrobial effect, a photoantimicrobial high-throughput screening (HTS) based on The European Committee on Antimicrobial Susceptibility Testing (EUCAST) was established. After validation, the established HTS was used to evaluate a sample set containing six colorful representatives from the genus Cortinarius (i.e., Cortinarius callisteus, C. rufo-olivaceus, C. traganus, C. trivialis, C. venetus, and C. xanthophyllus). The assay is built on a uniform, light-emitting diode (LED)-based light irradiation across a 96-well microtiter plate, which was achieved by a pioneering arrangement of the LEDs. The validation of the assay was accomplished with well-known photoactive drugs, so-called photosensitizers, utilizing six distinct emission wavelengths (λexc = 428, 478, 523, 598, or 640 nm) and three microbial strains (Candida albicans, Staphylococcus aureus, and Escherichia coli). Evaluating the extracts of six Cortinarius species revealed two highly promising species, i.e., C. rufo-olivaceus and C. xanthophyllus. Extracts from the latter were photoactive against the Gram-positive S. aureus (c = 7.5 μg/ml, H = 30 J/cm2, λ = 478 nm) and the fungus C. albicans (c = 75 μg/ml, H = 30 J/cm2, λ = 478 nm).

Abstract Species that cannot be easily distinguished based on morphology, but which form distinct phylogenetic lineages based on molecular markers, are often referred to as cryptic species. They have been proposed in a number of fungal genera, including the basidiomycete genus Fomes. The main aim of this work was to test new methods for species delimitation in cryptic lineages of polypores, and to define useful characters for species identification. A detailed examination of a number of different Fomes strains that had been collected and isolated from different habitats in Italy and Austria confirmed the presence of distinct lineages in the Fomes fomentarius clade. Our zero hypothesis was that the Mediterranean strains growing on Quercus represent a species which can be delimited based on morphological and physiological characters when they are evaluated in statistically relevant numbers. This hypothesis was tested based on phylogenetic analysis of the rDNA ITS region, morphological characters of basidiomes and pure cultures, growth rates and optimum growth temperature experiments, mycelial confrontation tests, enzyme activity tests and volatile organic compound (VOC) production. The Mediterranean lineage can unambiguously be delimited from F. fomentarius. A syntype of an obscure and previously synonymized name, Polyporus inzengae, represents the Mediterranean lineage that we recognize as Fomes inzengae, a distinct species. The rDNA ITS region is useful for delimitation of Fomes species. Moreover, also a variety of morphological characters including hymenophore pore size, basidiospore size, and diameter of skeletal hyphae are useful delimiting characters. The ecology is also very important, because the plant host appears to be a central factor driving speciation. Physiological characters turned also out to be species-specific, e.g. daily mycelial growth rates or the temperature range of pure cultures. The production of VOCs can be considered as a very promising tool for fast and reliable species delimitation in the future.

Mortierellaceae species are among the most frequent and globally distributed soil fungi. However, the factors shaping their diversity and distribution remain obscure. Several species have been reported to be associated to bacteria, but the kind and frequency of such associations were not addressed up to now. We hypothesized that such associations could be important for Mortierellaceae ecology. Therefore, our aim was to understand the driving factors responsible for the Mortierellaceae diversity, community composition and bacterial associations in alpine and subalpine habitats. For answering our question, we collected both snow-free and snow-covered soil at sampling sites from different habitats: bare alpine soil in a glacier forefield, alpine dwarf-willow habitats, and high-altitude Pinus cembra forests. The isolations were carried out by direct cultivation without any antibiotics to the isolation media. Altogether, we obtained 389 Mortierellaceae isolates representing 29 operational taxonomic units (OTUs). Many OTUs could be placed to the genera Mortierella sensu stricto, Dissophora, Entomortierella, Gamsiella, Linnemannia, and Podila, but others could not unambiguously be assigned to a genus. Our results demonstrate that both, the distribution as well as the diversity of the Mortierellaceae species, were significantly influenced by habitat, soil pH, and snow-cover. We noticed that >30% of our isolates were associated to a non-contaminant bacterium. The bacteria associated to our Mortierellaceae isolates belonged to seven different genera. Pseudomonas was the most frequently detected genus associated to the isolated Mortierellaceae species and it was found to be species-specific. Mortierellaceae–bacteria pairs, including those with Pseudomonas, were influenced by location, habitat, and snow-cover. The majority of the fungus–bacterium associations were potentially epihyphal, but we also detected potential endohyphal bacterial species belonging to Mycoavidus, Burkholderiaceae, and Paraburkholderia. Taken together, the non-random associations we detected suggest that fungus–bacterium associations are ecologically meaningful – an interesting path that needs to be investigated further.

The boletoid genera Butyriboletus and Exsudoporus have recently been suggested by some researchers to constitute a single genus, and Exsudoporus was merged into Butyriboletus as a later synonym. However, no convincing arguments have yet provided significant evidence for this congeneric placement. In this study, we analyze material from Exsudoporus species and closely related taxa to assess taxonomic and phylogenetic boundaries between these genera and to clarify species delimitation within Exsudoporus. Outcomes from a multilocus phylogenetic analysis (ITS, nrLSU, tef1-α and rpb2) clearly resolve Exsudoporus as a monophyletic, homogenous and independent genus that is sister to Butyriboletus. An accurate morphological description, comprehensive sampling, type studies, line drawings and a historical overview on the nomenclatural issues of the type species E. permagnificus are provided. Furthermore, this species is documented for the first time from Israel in association with Quercus calliprinos. The previously described North American species Exsudoporus frostii and E. floridanus are molecularly confirmed as representatives of Exsudoporus, and E. floridanus is epitypified. The eastern Asian species Leccinum rubrum is assigned here to Exsudoporus based on molecular evidence, and a new combination is proposed. Sequence data from the original material of the Japanese Boletus kermesinus were generated, and its conspecificity with L. rubrum is inferred as formerly presumed based on morphology. Four additional cryptic species from North and Central America previously misdetermined as either B. frostii or B. floridanus are phylogenetically placed but remain undescribed due to the paucity of available material. Boletus weberi (syn. B. pseudofrostii) and Xerocomus cf. mcrobbii cluster outside of Exsudoporus and are herein assigned to the recently described genus Amoenoboletus. Biogeographic distribution patterns are elucidated, and a dichotomous key to all known species of Exsudoporus worldwide is presented.

Fungi have developed a wide array of defense strategies to overcome mechanical injuries and pathogen infections. Recently, photoactivity has been discovered by showing that pigments isolated from Cortinarius uliginosus produce singlet oxygen under irradiation. To test if this phenomenon is limited to dermocyboid Cortinarii, six colourful Cortinarius species belonging to different classical subgenera (i.e., Dermocybe, Leprocybe, Myxacium, Phlegmacium, and Telamonia) were investigated. Fungal extracts were explored by the combination of in vitro photobiological methods, UHPLC coupled to high-resolution tandem mass spectrometry (UHPLC-HRMS2), feature-based molecular networking (FBMN), and metabolite dereplication techniques. The fungi C. rubrophyllus (Dermocybe) and C. xanthophyllus (Phlegmacium) exhibited promising photobiological activity in a low concentration range (1–7 µg/mL). Using UHPLC-HRMS2-based metabolomic tools, the underlying photoactive principle was investigated. Several monomeric and dimeric anthraquinones were annotated as compounds responsible for the photoactivity. Furthermore, the results showed that light-induced activity is not restricted to a single subgenus, but rather is a trait of Cortinarius species of different phylogenetic lineages and is linked to the presence of fungal anthraquinones. This study highlights the genus Cortinarius as a promising source for novel photopharmaceuticals. Additionally, we showed that putative dereplication of natural photosensitizers can be done by FBMN.

Due to their small size, microorganisms directly experience only a tiny portion of the environmental heterogeneity manifested in the soil. The microscale variations in soil properties constrain the distribution of fungi and bacteria, and the extent to which they can interact with each other, thereby directly influencing their behavior and ecological roles. Thus, to obtain a realistic understanding of bacterial–fungal interactions, the spatiotemporal complexity of their microenvironments must be accounted for. The objective of this review is to further raise awareness of this important aspect and to discuss an overview of possible methodologies, some of easier applicability than others, that can be implemented in the experimental design in this field of research. The experimental design can be rationalized in three different scales, namely reconstructing the physicochemical complexity of the soil matrix, identifying and locating fungi and bacteria to depict their physical interactions, and, lastly, analyzing their molecular environment to describe their activity. In the long term, only relevant experimental data at the cell-to-cell level can provide the base for any solid theory or model that may serve for accurate functional prediction at the ecosystem level. The way to this level of application is still long, but we should all start small.

This paper is a contribution to the current knowledge of taxonomy, ecology and distribution of South American Cortinarius (Pers.) Gray. Cortinarius is among the most widely distributed and species-rich basidiomycete genera occurring with South American Nothofagaceae and species are found in many distinct habitats, including shrublands and forests. Due to their ectomycorrhizal role, Cortinarius species are critical for nutrient cycling in forests, especially at higher latitudes. Some species have also been reported as edible fungi with high nutritional quality. Our aim is to unravel the taxonomy of selected Cortinarius belonging to phlegmacioid and myxotelamonioid species based on morphological and molecular data. After widely sampling Cortinarius specimens in Patagonian Nothofagaceae forests and comparing them to reference collections (including holotypes), we propose five new species of Cortinarius in this work. Phylogenetic analyses of concatenated rDNA ITS-LSU and RPB1 sequences failed to place these new species into known Cortinarius sections or lineages. These findings highlight our knowledge gaps regarding the fungal diversity of South American Nothofagaceae forests. Due to the high diversity of endemic Patagonian taxa, it is clear that the South American Cortinarius diversity needs to be discovered and described in order to understand the evolutionary history of Cortinarius on a global scale.

In ecology, Volatile Organic Compounds (VOCs) have a high bioactive and signaling potential. VOCs are not only metabolic products, but are also relevant in microbial cross talk and plant interaction. Here, we report the first large-scale VOC study of 13 different species of Mortierella sensu lato (s.l.) isolated from a range of different alpine environments. Proton Transfer Reaction–Time-of-Flight Mass Spectrometry (PTR–ToF–MS) was applied for a rapid, high-throughput and non-invasive VOC fingerprinting of 72 Mortierella s.l. isolates growing under standardized conditions. Overall, we detected 139 mass peaks in the headspaces of all 13 Mortierella s.l. species studied here. Thus, Mortierellas.l. species generally produce a high number of different VOCs. Mortierella species could clearly be discriminated based on their volatilomes, even if only high-concentration mass peaks were considered. The volatilomes were partially phylogenetically conserved. There were no VOCs produced by only one species, but the relative concentrations of VOCs differed between species. From a univariate perspective, we detected mass peaks with distinctively high concentrations in single species. Here, we provide initial evidence that VOCs may provide a competitive advantage and modulate Mortierella s.l. species distribution on a global scale.

Aboveground species richness patterns of vascular plants, aphyllophoroid macrofungi, bryophytes and lichens were compared along an altitudinal gradient (80–310 m a.s.l.) on the Slantsevaya mountain at the eastern macroslope of the Polar Urals (Russia). Five altitudinal levels were included in the study: (1) Northern boreal forest with larch-spruce in the Sob’ river valley habitats; (2–3) two levels of closed, northern boreal, larch-dominated forests on the slopes; (4) crook-stemmed forest; (5) tundra habitats above the timberline. Vascular plant or bryophyte species richness was not affected by altitudinal levels, but lichen species richness significantly increased from the river valley to the tundra. For aphyllophoroid macrofungi, species richness was highest at intermediate and low altitudes, and poorest in the tundra. These results indicate a positive ecotone effect on aphyllophoroid fungal species richness. The species richness of aphyllophoroid fungi as a whole was neither correlated to mortmass stocks, nor to species richness of vascular plants, but individual ecological or morphological groups depended on these parameters. Poroid fungal species richness was positively correlated to tree age, wood biomass and crown density, and therefore peaked in the middle of the slope and at the foot of the mountain. In contrast, clavarioid fungal species richness was negatively related to woody bio- and mortmass, and therefore peaked in the tundra. This altitudinal level was characterized by high biomass proportions of lichens and mosses, and by high litter mortmass. The proportion of corticoid fungi increased with altitude, reaching its maximum at the timberline. Results from the different methods used in this work were concordant, and showed significant patterns. Tundra communities differ significantly from the forest communities, as is also confirmed by nonmetric multidimensional scaling (NMDS) analyses based on the spectrum of morphological and ecological groups of aphyllophoroid fungi.

Mycophiles forage for and pick vast quantities of a wide variety of wild mushroom species. As a result, mushroom intoxications are comparatively frequent in such countries with mycophiles. Thus, national governments are forced to release guidelines or enact legislation in order to ensure the safe commerce of wild mushrooms due to food safety concerns. It is in these guidelines and laws that one can observe whether a country is indeed mycophobic or mycophilic. Furthermore, these laws and guidelines provide valuable information on mushroom preferences and on the consumption habits of each country. As such we were interested in the questions as to whether mushroom consumption behaviour was different within Europe, and if it was possible to discover the typical or distinctive culinary preferences of Slavic or Romanic speaking people, people from special geographical regions or from different zones. This work is based on the analysis of edible mushroom lists available in specific guidelines or legislation related to the consumption and commerce of mushrooms in 27 European countries. The overall diversity of edible mushrooms authorised to be commercialised in Europe is very high. However, only 60 out of a total 268 fungal species can be cultivated. This highlights the importance of guidelines or legislation for the safe commerce of wild mushrooms. The species richness and composition of the mushrooms listed for commerce is very heterogeneous within Europe. The consumption behaviour is not only language-family-related, but is strongly influenced by geographical location and neighbouring countries. Indicator species were detected for different European regions; most of them are widespread fungi, and thus prove culture-specific preferences for these mushrooms. Our results highlight tradition and external input such as trade and cultural exchange as strong factors shaping mushroom consumption behaviour.

Fungal pure cultures identified with both classical morphological methods and through barcoding sequences are a basic requirement for reliable reference sequences in public databases. Improved techniques for an accelerated DNA barcode reference library construction will result in considerably improved sequence databases covering a wider taxonomic range. Fast, cheap, and reliable methods for obtaining DNA sequences from fungal isolates are, therefore, a valuable tool for the scientific community. Direct colony PCR was already successfully established for yeasts, but has not been evaluated for a wide range of anamorphic soil fungi up to now, and a direct amplification protocol for hyphomycetes without tissue pre-treatment has not been published so far. Here, we present a colony PCR technique directly from fungal hyphae without previous DNA extraction or other prior manipulation. Seven hundred eighty-eight fungal strains from 48 genera were tested with a success rate of 86%. PCR success varied considerably: DNA of fungi belonging to the genera Cladosporium, Geomyces, Fusarium, and Mortierella could be amplified with high success. DNA of soil-borne yeasts was always successfully amplified. Absidia, Mucor, Trichoderma, and Penicillium isolates had noticeably lower PCR success.

Abstract  The bog sedge Kobresia myosuroides is among the first ectomycorrhizal (EM) plants forming dense pads on receding glacier forefronts of the Austrian Alps. This is the only Cyperaceae species known to form EM. To date, little is known about fungal species involved in these EM associations. Therefore, the main aim of this study was to detect EM fungal communities of K. myosuroides (1) by describing mycorrhizal morphotypes (MT) and (2) by identifying the mycobionts by rDNA internal transcribed spacer (ITS) sequencing. Furthermore, seasonal dynamics of Kobresia mycobionts were investigated. Sampling was performed in all four seasons (also under snow cover) during the years 2005 and 2006 at the Rotmoos glacier forefront, a well-characterized alpine primary successional habitat in the Austrian alps (2,300 m above sea level). The degree of EM infection of K. myosuroides roots was high (95%). Ten MTs were described and sequences of 18 fungal taxa were obtained. This was the highest mycobiont diversity ever reported for this plant. Cenococcum geophilum was the most abundant mycobiont (37–46%) and shared dominancy with Sebacina incrustans (16–44%) and Tomentella spp. (7–37%). Tomentella (including Thelephora) was the most species-rich mycobiont genus with five taxa, followed by Cortinarius, Inocybe, and Sebacina with two taxa each and one Hebeloma species. Other ascomycete mycobionts beside C. geophilum were Helvella sp., Lecythophora sp., and one Pezizales species. Due to high interannual differences in the EM fungal community, no significant seasonal changes could be detected. The importance of fungal mycobionts in alpine habitats is discussed. [ABSTRACT FROM AUTHOR]

Abstract  The effect of various media formulations on in vitro ectomycorrhizal synthesis of identified fungal strains with European aspen (Populus tremula L.) was tested in Petri dishes. Pre-grown seedlings were transferred to various nutrient media and inoculated with Paxillus involutus isolates using modified sandwich techniques. Mycorrhiza formation was evaluated macroscopically and further confirmed by microscopic examination of semi-thin sections for anatomical features of the mantle and the Hartig net. Standard media formulations did not support successful ectomycorrhiza formation because of either very poor plant survival (below 20%) or impaired fungal growth. The inclusion of micronutrients and vitamins in a Melin Norkrans (MMN)-based medium increased plant survival rate to above 60% and supported successful mycorrhizal synthesis. P. involutus isolates formed mycorrhizas with a characteristic Hartig net restricted to the epidermis. Mantle density and thickness varied depending on the isolate. In a follow-up experiment, the adapted medium supported successful ectomycorrhiza formation by various Laccaria and Hebeloma isolates. Our results show that an exogenous supply of vitamins and micronutrients in the medium was a prerequisite for successful mycorrhization of P. tremula in vitro in Petri dishes. [ABSTRACT FROM AUTHOR]

Abstract  Dwarf willows (e.g. Salix herbacea) are among the earliest ectomycorrhizal (EM) plants colonising primary successional sites such as glacier forefronts in the Tyrolean Alps. EM of S. herbacea were sampled at the Rotmoos glacier forefront (Ötz Valley, Austria) three times a year during the growing season and once a year during winter when plants were covered with snow in 2005 and 2006. EM were investigated using morphological methods and by sequencing the rDNA ITS region. The degree of EM mycorrhization was high throughout both years (93%). We distinguished 21 EM morphotypes and identified 19 fungal species. Cenococcum geophilum, Sebacina spp., Tomentella spp. and Cortinarius spp. dominated the mycobiont community of S. herbacea. The observed species richness in this about 150-year-old soil was at least 59% of the estimated species richness. Fungal communities differed significantly between consecutive years, and spatial heterogeneity was high. These differences made it difficult to detect seasonal impacts. Abundances of C. geophilum EM increased throughout the 2-year sampling period. Sebacina incrustans EM were very abundant in 2005, but nearly disappeared in 2006, whilst its fruitbodies were still frequent in the sampling area. This suggests that the mycorrhizae were displaced from the roots by an outcompeting species, whereas the mycelium was still present in the soil. [ABSTRACT FROM AUTHOR]

Abstract   Polygonum viviparum is one of the first ectomycorrhizal (EM) plant species colonising primary successional sites at the Rotmoos glacier forefront (Tyrolean Alps, Austria). On a site with soil development of about 150 years (2,400 m above sea level), mycobionts of P. viviparum were identified by morphotyping and fungal ribosomal deoxyribonucleic acid internal transcribed spacer sequencing. For studying seasonal dynamics and spatial heterogeneity, ectomycorrhizae were sampled on five plots during all seasons. P. viviparum root tips were always EM. In total, 18 mycobiont taxa of the following genera were identified: Cenococcum (1), Cortinarius (2), Helvella (1), Inocybe (3), Russula (1), Sebacina (2), Thelephora (2) and Tomentella (6). All were non-specific EM partners of EM plants. As early as 2 weeks after spring snow melt, EM were well developed, vital and showed high mycobiont diversity. The relative abundance of senescent root tips was lowest in spring and increased throughout the year, with a maximum in winter (frozen soil). Thus, mycobiont growth and physiological activity obviously start when soil is still under snow cover: We speculate that water availability is one important initiation factor for mycorrhizal development under snow cover, when temperatures still range around the freezing point. Irrespectively of the season, most abundant mycobionts at this primary successional site belonged to the genera Tomentella, Sebacina and Cenococcum, also in frozen soil. Spatial heterogeneity was high when considering species composition and diversity indices. Overall mycobionts species richness was restricted at this site, probably because of the limited availability of fungal partners. We regard the presence/absence of fungal partner and limiting abiotic impacts of the environment as key factors for the symbiotic status of P. viviparum. [ABSTRACT FROM AUTHOR]

Species delimitation is still controversial in the Xerocomus chrysenteron complex. We have therefore established comprehensible and reliable species concepts based on statistical evaluation of morphological and ecological characters. We examined many collections from different geographical regions and different developmental stages within collections. Quantitative micromorphological characters (basidiospores, pileipellis end cells) were measured in statistically relevant numbers. The same material was used to generate 24 rDNA-LSU sequences, and the results of phylogenetic analyses clearly confirmed our species concepts: spore size and ornamentation, length of the pileipellis end cells and ‘pruinatus-hyphae’ are most valuable characters for the delimitation of species in this complex. Molecular data demonstrated that the X. chrysenteron complex is a monophyletic group. All the examined species (X. chrysenteron, X. cisalpinus, X. pruinatus, X. ripariellus, X. dryophilus, X. fennicus, X. porosporus, and X. rubellus) represent independent lineages. The faintly striate spores, a key character characterising species of section Striatulispori, probably evolved independently. In addition, the ‘pruinatus-hyphae’ have multiple origins, and truncate spore apices are derived at least twice. Xerocomus cisalpinus sp. nov. is characterised by striate spores, the presence of ‘pruinatus-hyphae’ and a pileipellis strongly reminiscent of X. chrysenteron. For reasons of discussion, microscopical data are presented on Boletellus episcopalis for the first time. Xerocomus fennicus (Boletellus) comb. nov. is proposed. We provide descriptions to all included taxa. Our results once more demonstrate that reliably identified and characterised voucher collections are the basic requirement for meaningful phylogenetic studies. [ABSTRACT FROM AUTHOR]

Three new Cortinarius species, Cortinarius conopileus, C. keralensis, and C. phlegmophorus spp. nov., are described from Kerala State in southern India. This is the first record of ectomycorrhizal Cortinarius spp. in the tropical part of India. In addition to distinct morphological characters, the comparative analysis of rDNA ITS sequences of the collections from India and morphologically similar species support the recognition of these taxa as new species. Phylogenetic analyses demonstrate that the three Indian Cortinarius spp. belong to both larger subclades of the genus Cortinarius, clade/cortinarius and clade/telamonia. As supported by morphological and molecular data, C. phlegmophorus belongs to Cortinarius subgen. Myxacium sect. Defibulati. Based on classical morphological characters, both C. keralensis and C. conopileus are representatives of subgen. Telamonia. However, C. conopileus belongs to clade/obtusi, which is a well-supported subclade of clade/cortinarius. Thus, in contrast to classical taxonomy, the clade/obtusi represents an independent evolutionary origin of telamonioid taxa. This result is also reflected by the distinct morphological characters of taxa of clade/obtusi, namely the lamellar trama with ellipsoid inflated hyphae and the presence of cystidia. In contrast, C. keralensis is a typical member of clade/telamonia. Within/telamonia, only relationships of closely related taxa are resolved due to the low genetic divergence found in ITS sequences. Based on morphological and molecular criteria, C. keralensis is a distinct taxon of sect. Saturnini. [ABSTRACT FROM AUTHOR]

The leading agaricologist Meinhard M. Moser died on 30 September 2002. He was a Centenary Fellow of the British Mycological Society, and the mentor of numerous students and colleagues throughout the world. [ABSTRACT FROM AUTHOR]