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Unraveling the assembly processes of ectomycorrhizal (ECM) fungal communities in changing environments is crucial for forecasting the impacts of climate change on forests. However, the assembly processes and key drivers of root-associated ECM fungal communities in alpine coniferous forests remain poorly understood. To address this knowledge gap, we conducted sampling in 65 monodominant alpine coniferous forests, which encompass 11 plant species belonging to three genera (Abies, Pinus, and Picea) within the Pinaceae family, all located on the Qinghai-Tibetan Plateau. We employed a combination of null model and multivariate analyses to elucidate the drivers and assembly processes of ECM fungal communities. Our results revealed significant variation in the composition and diversity of root-associated ECM fungal communities among Abies, Pinus, and Picea, indicating specific preferences for ECM fungi among Pinaceae genera. Importantly, mean annual temperature (MAT) emerged as the primary driver of these variations and regulated the assembly processes within the community of root-associated ECM fungi. As MAT temperature, the α-diversity of these fungi significantly decreased, suggesting that increased temperature may reduce the species diversity of root-associated ECM fungi in alpine forests. Furthermore, stochastic processes, such as dispersal limitation and drift, became more influential as MAT increased. Conversely, the role of deterministic processes, particularly heterogeneous selection, in shaping the ECM fungal community assembly weakened with increasing MAT. This study provides novel theoretical insights into the processes of ECM fungal community assembly in alpine forests, emphasizing the pivotal role of temperature in regulating the assembly processes and compositional dynamics of root-associated ECM fungal communities in these unique environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Lodgepole pine, a prominent Pinaceae tree species native to western North America, is well-known for its ability to thrive in highly disturbed and degraded areas. One such area is the Sub-Boreal Pine-Spruce xeric-cold (SBPSxc) region in British Columbia, Canada, which is characterized by weakly-developed, parched soils that lack an organic forest floor and essential plant-available nutrients. We hypothesized that plant growth-promoting bacteria could play a significant role in sustaining the growth of lodgepole pine trees in the SBPSxc region. Testing this hypothesis, we evaluated plant growth-promoting abilities of six endophytic bacterial strains previously isolated from lodgepole pine trees growing in this region. These bacterial strains significantly enhanced the length and biomass of their natural host (lodgepole pine) as well as a foreign host (hybrid white spruce) in a 540-day long greenhouse trial. This growth stimulation could be linked to the diverse plant growth-promoting (PGP) abilities detected in these strains using in vitro assays for inorganic/organic phosphate-solubilization, siderophore production IAA production, ACC deaminase activity, lytic enzymes (chitinase, β-1,3-glucanase, protease, and cellulase) activity, ammonia production and catalase activity. ACC deaminase activity was also detected in vivo for all strains using ethylene-sensitive plants-canola and tomato. Notably, strains belonging to the Burkholderiaceae family (HP-S1r, LP-R1r and LP-R2r) showed the greatest potential in all PGP assays and enhanced pine and spruce seedling length and biomass by up to 1.5-fold and 4-fold, respectively. Therefore, such bacterial strains with multifarious PGP abilities could be crucial for survival and growth of lodgepole pine trees in the SBPSxc region and could potentially be utilized as bioinoculant for Pinaceae trees in highly disturbed and nutrient-poor ecosystems., Competing Interests: The authors have declared that no competing interests exist.

Root-associated mycobiomes (RAMs) link plant and soil ecological processes, thereby supporting ecosystem functions. Understanding the forces that govern the assembly of RAMs is key to sustainable ecosystem management. Here, we dissected RAMs according to functional guilds and combined phylogenetic and multivariate analyses to distinguish and quantify the forces driving RAM assembly processes. Across large biogeographic scales (>1,000 km) in temperate forests (>100 plots), RAMs were taxonomically highly distinct but composed of a stable trophic structure encompassing symbiotrophic, ectomycorrhizal (55%), saprotrophic (7%), endotrophic (3%) and pathotrophic fungi (<1%). Taxonomic community composition of RAMs is explained by abiotic factors, forest management intensity, dominant tree family (Fagaceae, Pinaceae) and root resource traits. Local RAM assemblies are phylogenetically clustered, indicating stronger habitat filtering on roots in dry, acid soils and in conifer stands than in other forest types. The local assembly of ectomycorrhizal communities is driven by forest management intensity. At larger scales, root resource traits and soil pH shift the assembly process of ectomycorrhizal fungi from deterministic to neutral. Neutral or weak deterministic assembly processes are prevalent in saprotrophic and endophytic guilds. The remarkable consistency of the trophic composition of the RAMs suggests that temperate forests attract fungal assemblages that afford functional resilience under the current range of climatic and edaphic conditions. At local scales, the filtering processes that structure symbiotrophic assemblies can be influenced by forest management and tree selection, but at larger scales, environmental cues and host resource traits are the most prevalent forces., (© 2018 John Wiley & Sons Ltd.)

Despite the importance of ectomycorrhizal (ECM) fungi in forest ecosystems, knowledge about the ecological and co-evolutionary mechanisms underlying ECM host associations remains limited. Using a widely distributed group of ECM fungi known to form tight associations with trees in the family Pinaceae, we characterized host specificity among three unique Suillus-host species pairs using a combination of field root tip sampling and experimental bioassays. We demonstrate that the ECM fungus S. subaureus can successfully colonize Quercus hosts in both field and glasshouse settings, making this species unique in an otherwise Pinaceae-specific clade. Importantly, however, we found that the colonization of Quercus by S. subaureus required co-planting with a Pinaceae host. While our experimental results indicate that gymnosperms are required for the establishment of new S. subaureus colonies, Pineaceae hosts are locally absent at both our field sites. Given the historical presence of Pineaceae hosts before human alteration, it appears the current S. subaureus-Quercus associations represent carryover from past host presence. Collectively, our results suggest that patterns of ECM specificity should be viewed not only in light of current forest community composition, but also as a legacy effect of host community change over time., (© 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.)

The complexity of ecological conditions in urban areas imposes the plant species need for the development of various biochemical and physiological adaptive strategies. The aim of our research was to examine the antioxidative and antifungal metabolism of species Pinus nigra, Picea omorika, Tilia cordata and Betula pendula from the area of Banja Luka City (urban area) during two vegetation seasons (spring and autumn) and compared with the same species from forest habitats. Changes in the protein concentration, activity and isoenzyme profiles of peroxidases (POD, EC 1.11.1.7), content and antioxidative activity of total phenols and antifungal activity in leaves and needles of the plants from the urban area and forest habitats were monitored. The obtained results indicate that urban areas induce changes in antioxidative metabolism in all examined species, but that the response is species specific. The most sensitive parameter that indicates different adaptation strategy of Pinus nigra, Picea omorika, Tilia cordata and Betula pendula to environment conditions in the urban area were peroxidase isoenzyme patterns. Less specific parameter was phenol content even though there are some indications for role of their antioxidative capacity in the adjustment to specific habitat. In addition, each species had different metabolic strategy to cope with the changes caused by the urban environment.

Tricholoma matsutake (pine mushroom) (Basidiomycota, Agaricales) is a valuable edible fungal species that cannot be cultivated artificially. As an ectomycorrhizal fungus, T. matsutake interacts with trees belonging to the Pinaceae and Fagaceae, and forms fairy rings around host trees that are arc-shaped areas with dense hyphae of T. matsutake in the soil. Because the fairy rings maintain their dense hyphae for several years and form fruiting bodies, the characteristics of the fairy ring may be important in understanding the ecology of T. matsutake. Recent studies have shown that diverse bacteria co-exist in the fairy ring, and suggest that the fairy ring bacteria may influence on the growth of T. matsutake. However, the effect of the fairy ring bacteria on the growth of T. matsutake is largely unknown. In this study, we isolated fairy ring bacteria and investigated their effect on the growth of T. matsutake in co-culture experiments. In addition, the relationship between bacterial effects and nutrient conditions was tested using different media with varying glucose concentrations. A total of 237 bacteria (28 species) were isolated from fairy rings of four different T. matsutake producing areas: Proteobacteria (17 species), Firmicutes (7 species), and Actinobacteria (4 species). Burkholderiaceae (Burkholderia and Paraburkholderia) was most abundant in the fairy ring bacteria communities. Most bacteria showed a negative effect on the growth of T. matsutake when it grew on glucose rich medium (20 g/L). In glucose deficient medium (2 g/L), however, some bacteria promoted the growth of T. matsutake. In addition, the mode of interaction between bacteria and T. matsutake is different, depending on the glucose concentration.

We investigated the diversity of ectomycorrhiza associated with the endemic Picea crassifolia in Mount Helan National Nature Reserve in Inner Mongolia, China. Toward this objective, we conducted morphological and molecular identification of ectomycorrhizae in soil cubes taken from pure P. crassifolia stands. Eleven types of ectomycorrhizal (ECM) organisms were separated, briefly described, and identified. Nine morphotypes belonged to the phylum Basidiomycotina [Amphinema byssoides, Cortinarius sp (cf. limonius), Cortinarius vernus, Inocybe cf. nitidiscula, Inocybe sp 1, Sebacina incrustans, Sebacina sp, Suillus luteus, and Piceirhiza tuberculata x Picea crassifolia (comb. Nov.)], and two morphotypes to the phylum Ascomycotina (Cenococcum geophilum and Helvella sp). The diversity of ECM organisms in P. crassifolia was lower than that reported by other studies on spruce or pine forests, or on sporocarp diversity in the high-mountain forests of China. Most of the fungi in the rhizosphere did not correspond to species previously recorded as sporocarps above ground. Here, several new ectomycorrhiza morphotypes are proposed and described. We also confirmed the ectomycorrhizal status of the genus Sebacina (order Sebacinales)., Competing Interests: The authors declare no conflict of interest.

Background: The increasing awareness of the role of phyllosphere microbial communities in plant health calls for a greater understanding of their structure and dynamics in natural ecosystems. Since most knowledge of tree phyllosphere bacterial communities has been gathered in tropical forests, our goal was to characterize the community structure and assembly dynamics of phyllosphere epiphytic bacterial communities in temperate forests in Quebec, Canada. We targeted five dominant tree species: Acer saccharum, Acer rubrum, Betula papyrifera, Abies balsamea, and Picea glauca. We collected 180 samples of phyllosphere communities on these species at four natural forest sites, three times during the growing season., Results: Host functional traits (i.e., wood density, leaf nitrogen content) and climate variables (summer mean temperature and precipitation) were strongly correlated with community structure. We highlight three key findings: (1) temperate tree species share a "core microbiome"; (2) significant evolutionary associations exist between groups of bacteria and host species; and (3) a greater part of the variation in phyllosphere bacterial community assembly is explained by host species identity (27 %) and species-site interaction (14 %), than by site (11 %) or time (1 %)., Conclusions: We demonstrated that host species identity is a stronger driver of temperate tree phyllosphere bacterial communities than site or time. Our results suggest avenues for future studies on the influence of host functional traits on phyllosphere community functional biogeography across terrestrial biomes.

Understanding the ecology of coniferous forests is very important because these environments represent globally largest carbon sinks. Metatranscriptomics, microbial community and enzyme analyses were combined to describe the detailed role of microbial taxa in the functioning of the Picea abies-dominated coniferous forest soil in two contrasting seasons. These seasons were the summer, representing the peak of plant photosynthetic activity, and late winter, after an extended period with no photosynthate input. The results show that microbial communities were characterized by a high activity of fungi especially in litter where their contribution to microbial transcription was over 50%. Differences in abundance between summer and winter were recorded for 26-33% of bacterial genera and < 15% of fungal genera, but the transcript profiles of fungi, archaea and most bacterial phyla were significantly different among seasons. Further, the seasonal differences were larger in soil than in litter. Most importantly, fungal contribution to total microbial transcription in soil decreased from 33% in summer to 16% in winter. In particular, the activity of the abundant ectomycorrhizal fungi was reduced in winter, which indicates that plant photosynthetic production was likely one of the major drivers of changes in the functioning of microbial communities in this coniferous forest., (© 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.)

Coinvasive ectomycorrhizal (ECM) fungi allow Pinaceae species to invade regions otherwise lacking compatible symbionts, but ECM fungal communities permitting Pinaceae invasions are poorly understood. In the context of Pinaceae invasions on Isla Victoria, Nahuel Huapi National Park, Argentina, we asked: what ECM fungi are coinvading with Pinaceae hosts on Isla Victoria; are some ECM fungal species or genera more prone to invade than others; and are all ECM fungal species that associate with Northern Hemisphere hosts also nonnative, or are some native fungi compatible with nonnative plants? We sampled ECMs from 226 Pinaceae host plant individuals, both planted individuals and recruits, growing inside and invading from plantations. We used molecular techniques to examine ECM fungal communities associating with these trees. A distinctive subset of the ECM fungal community predominated far from plantations, indicating differences between highly invasive and less invasive ECM fungi. Some fungal invaders reported here have been detected in other locations around the world, suggesting strong invasion potential. Fungi that were frequently detected far from plantations are often found in early-successional sites in the native range, while fungi identified as late-successional species in the native range are rarely found far from plantations, suggesting a means for predicting potential fungal coinvaders., (© 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.)

Tricholoma matsutake is an ectomycorrhizal basidiomycete that associates with Pinaceae in the Northern Hemisphere and produces prized "matsutake" mushrooms. We questioned whether the symbiont could associate with a birch that is an early-successional species in boreal, cool-temperate, or subalpine forests. In the present study, we demonstrated that T. matsutake can form typical ectomycorrhizas with Betula platyphylla var. japonica; the associations included a Hartig net and a thin but distinct fungal sheath, as well as the rhizospheric mycelial aggregate "shiro" that is required for fruiting in nature. The in vitro shiro also emitted a characteristic aroma. This is the first report of an ectomycorrhizal formation between T. matsutake and a deciduous broad-leaved tree in the boreal or cool-temperate zones that T. matsutake naturally inhabits.

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.

"Matsutake" mushrooms are formed by several species of Tricholoma sect. Caligata distributed across the northern hemisphere. A phylogenetic analysis of matsutake based on virtually neutral mutations in DNA sequences resolved robust relationships among Tricholoma anatolicum, Tricholoma bakamatsutake, Tricholoma magnivelare, Tricholoma matsutake, and Tricholoma sp. from Mexico (=Tricholoma sp. Mex). However, relationships among these matsutake and other species, such as Tricholoma caligatum and Tricholoma fulvocastaneum, were ambiguous. We, therefore, analyzed genomic copy numbers of σ marY1 , marY1, and marY2N retrotransposons by comparing them with the single-copy mobile DNA megB1 using real-time polymerase chain reaction (PCR) to clarify matsutake phylogeny. We also examined types of megB1-associated domains, composed of a number of poly (A) and poly (T) reminiscent of RNA-derived DNA elements among these species. Both datasets resolved two distinct groups, one composed of T. bakamatsutake, T. fulvocastaneum, and T. caligatum that could have diverged earlier and the other comprising T. magnivelare, Tricholoma sp. Mex, T. anatolicum, and T. matsutake that could have evolved later. In the first group, T. caligatum was the closest to the second group, followed by T. fulvocastaneum and T. bakamatsutake. Within the second group, T. magnivelare was clearly differentiated from the other species. The data suggest that matsutake underwent substantial evolution between the first group, mostly composed of Fagaceae symbionts, and the second group, comprised only of Pinaceae symbionts, but diverged little within each groups. Mobile DNA markers could be useful in resolving difficult phylogenies due to, for example, closely spaced speciation events.

Introduction of exotic plants change soil microbial communities which may have detrimental ecological consequences for ecosystems. In this study, we examined the community structure and species richness of ectomycorrhizal (EcM) fungi associated with exotic pine plantations in relation to adjacent native ectomycorrhizal trees in Iran to elucidate the symbiont exchange between distantly related hosts, i.e. Fagales (Fagaceae and Betulaceae) and Pinaceae. The combination of morphological and molecular identification approaches revealed that 84.6 % of species with more than one occurrence (at least once on pines) were shared with native trees and only 5.9 % were found exclusively on pine root tips. The community diversity of ectomycorrhizal fungi in the pine plantations adjacent to native EcM trees was comparable to their adjacent native trees, but the isolated plantations hosted relatively a species-poor community. Specific mycobionts of conifers were dominant in the isolated plantation while rarely found in the plantations adjacent to native EcM trees. These data demonstrate the importance of habitat isolation and dispersal limitation of EcM fungi in their potential of host range expansion. The great number of shared and possibly compatible symbiotic species between exotic Pinaceae and local Fagales (Fagaceae and Betulaceae) may reflect their evolutionary adaptations and/or ancestral compatibility with one another.

The ectomycorrhizal status of Keteleeria species is reported for the first time based on morphological and molecular analyses of root tips from southwestern China. Based on internal transcribed spacer rDNA sequences, we detected 26 ectomycorrhizal (ECM) fungal species on roots of Keteleeria evelyniana and Keteleeria davidiana collected from natural sites and a botanical garden in Kunming, China. These ECM symbionts represent six fungal lineages, including /russula-lactarius, /inocybe, /sebacina, /tomentella-thelephora, /wilcoxina, and /cenococcum. Our results provide the first evidence of ECM formation by Keteleeria and also supply ecologically important information for conservation and restoration efforts to recover populations of Keteleeria.

The complete sequences of two double-stranded RNA segments from the fungus Heterobasidion parviporum were characterized. The larger segment (2,290 bp) contained an open reading frame encoding a putative RNA-dependent RNA polymerase (RdRp, 722 aa), while the smaller one (2,238 bp) encoded a putative coat protein of 659 aa. Based on phylogenetic analysis, the dsRNA segments constitute the genome of a new virus assigned to the family Partitiviridae and named Heterobasidion RNA virus 2 (HetRV2). The RdRp segment was clearly related to H. annosum P-type partitivirus (aa similarity of 59%) but was only distantly related to previously described viruses of H. parviporum (aa similarity 26-35%). The dsRNA could be experimentally transmitted to all five species of the Heterobasidion annosum sensu lato complex and two species of the H. insulare complex, indicating that horizontal transfer between these intersterile fungal species is possible.

Tricholoma matsutake produces commercially valuable, yet uncultivable, mushrooms (matsutake) in association with pines in the Far East and Scandinavia and with both pines and oaks in the foothills of Tibet. Other matsutake mushrooms, such as Tricholoma anatolicum from the Mediterranean regions and Tricholoma magnivelare and Tricholoma sp. from the North Pacific Coast area of Canada and North America as well as Mexico, respectively, are associated with pines or oaks in their natural habitats. Tricholoma bakamatsutake and Tricholoma fulvocastaneum from Asia produce moderately valuable matsutake mushrooms and are solely associated with Fagaceae in nature. In this study, we demonstrate for the first time that matsutake mushrooms from Scandinavia, Mediterranean regions, North America, and Tibet form ectomycorrhizae with Pinus densiflora similar to the Far East T. matsutake. In general, worldwide T. matsutake and the symbionts of Pinaceae colonize the rhizospheres of P. densiflora as well as T. matsutake isolated from the host plant. However, T. fulvocastaneum and T. bakamatsutake formed a discontinuous Hartig net and no Hartig net, respectively, and colonized to a lesser extent as compared to T. matsutake. The data suggest that conifer-associated matsutake mushrooms in their native habitat will associate symbiotically with the Asian red pine.

Fungal communities in decaying sapwood and heartwood of K. evelyniana were demonstrated through construction of four 18 S rRNA gene libraries. The 210 sequenced clones were clustered into 11 subgroups, belonging to Basidiomycota (71.9%) and to Ascomycota (22.4%) and unclassified (1 subgroup; 5.7%). The heartwood displayed higher species richness than the sapwood. Basidiomycota were dominant in either the heartwood or the sapwood. Phylogenetically diverse Homobasidiomycetes were detected in the heartwood, contrary to the sapwood, where Heterobasidiomycetes were detected. Clones close to Spongipellis unicolor dominated in the heartwood (21 of 99 clones), while those close to Hydnochaete olivacea dominated in the sapwood (41 of 111 clones). The common species between the two parts were those related to S. unicolor, Calocera cornea, Debaryomyces hansenii, Davidiella tassiana, and Nomuraea rileyi and those from Chaetothyriomycetes.

Cronartium ribicola, the causal agent of white pine blister rust, has been devastating to five-needled white pines in North America since its introduction nearly a century ago. However, dynamic and complex interactions occur among C. ribicola, five-needled white pines, and the environment. To examine potential evolutionary influences on genetic structure and diversity of C. ribicola in western United States, population genetic analyses of C. ribicola were conducted using amplified fragment length polymorphism (AFLP) molecular markers. The fungus was sampled at six sites. Collections for two of the six sites were from separate plantings of resistant-selected western white pine and sugar pine. Heterozygosity based on polymorphic loci among populations ranged from 0.28 to 0.40, with resistant-selected plantations at the extremes. Genetic differentiation was also highest between these two populations. Principal coordinates analysis and Bayesian assignment placed most isolates that are putative carriers of virulence to major-gene resistance into a discernable cluster, while other isolates showed no clustering by site or host species. These results indicate that C. ribicola in western North America is not genetically uniform, despite its presumed single site of introduction and relatively brief residence. Moreover, major-gene resistance appears to have imposed strong selection on the rust, resulting in reduced genetic diversity. In contrast, no evidence of selection was observed in C. ribicola from hosts that exhibit only multigenic resistance.

Objective: To research molluscicidal effect activity, active components and stable passage of endophyte JJ18 from Pseudolarix amabilis and examine the possibility for practical application., Method: Molluscicidal effect test was performed according to the immersion test method suggested by WHO., Result: Immersion test with JJ18 broth showed that the active components were extracellular moiety of the broth and that 10% concentration solution could kill nearly 90% snail immersed after 72 h, the salified broth has favourable thermostabily and photostability and showed that JJ18 has stable passage and its active components concentrate in the extract of n-butanol., Conclusion: The metabolite of endophyte JJ18 has activity for molluscicidal effect and potential for application.

Hydnellum and Phellodon species, generally considered ectomycorrhizal partners of a range of woody angiosperms and gymnosperms particularly within Fagaceae and Pinaceae, appear to be declining in continental Europe. They are listed as priority species in the UK Biodiversity Action Plan, but their UK conservation status remains uncertain. Interpretation of species distribution data is hampered by a lack of consensus regarding some key discriminatory morphological characters and difficulties with their interpretation. DNA sequencing of the ITS1 region of the ribosomal gene cluster discriminated between the known British species of Phellodon but revealed more terminal clusters than currently recognised taxa. Although the main focus within Hydnellum was on the very similar species pair H. concrescens and H. scrobiculatum, a few samples of H. caeruleum, H. ferrugineum, H. peckii, and H. spongiosipes were included in the study for reference. DNA sequencing of material identified on spore-based criteria as H. concrescens yielded two main groups, but samples received as H. scrobiculatum were generally more variable. Of these, two were reassigned and the remaining group, with very similar spores (although shorter than in published descriptions of H. scrobiculatum), had highly variable sequence data. The results and conservation importance of these fungi highlight the need for a taxonomic reassessment of P. melaleucus, P. niger, H. concrescens, and H. scrobiculatum collections from Britain and continental Europe using a combined molecular and morphological approach. Specific PCR primers were constructed to discriminate fruit bodies, mycelium, and mycorrhizal roots of P. niger and P. confluens from each other and from other stipitate hydnoids.

To advance our understanding of host effects on the community structure of ectomycorrhizal fungi (EMF), EMF communities were compared among different host species, genera and families in two mixed conifer-broadleaf forests in Japan. Using molecular identification methods we examined EMF root tips of eight coexisting species belonging to six genera (three families): Abies and Tsuga (Pinaceae), Betula and Carpinus (Betulaceae) and Fagus and Quercus (Fagaceae). In total, 205 EMF species were detected, and the total richness was estimated to exceed 300 species using major estimators. Of the 55 EMF species occurring three or more times, eight showed significantly biased host preference. A Mantel test showed a significantly negative correlation between EMF community similarity and host taxonomic distance. Detrended correspondence analysis separated EMF communities mainly by host taxonomic and successional status. Thus, EMF communities are similar on hosts with similar taxonomic and successional status. A significant proportion of EMF exhibited host specificity, which may contribute to the extremely diverse EMF community in conifer-broadleaf forests.

Objective: To screen antifungal activity of endophytes from Pseudolarix kaempferi., Method: Endophytes from P. kaempferi were separated. By means of microdilution method, antifungal active endophytes were fast screened by Pyricularia oryzae P-2b model, and activity of endophytes against pathogenic fungus was studied., Result: 44.8% of endophytes showed activity against P. oryzae P-2b in Pseudolarix kaempferi. Among them JJ314, JJ323 introduced formation of characteristic beads and swellings on the growing hyphae, JJ324 inhibited the conidia germination. They all showed activity against Trichophyton rubrum, Cryptococcus neoformans and Candida albicans., Conclusion: Endophytes from P. kaempferi are a potential resource for the development of antifungal agent.

Cathaya argyrophylla, a critically endangered conifer, is found to grow at four isolated areas located in subtropical mountains of China. To examine the involvement and usefulness of mycorrhizas for sustaining the population of this tree, we compared the root system, morphology, and structure of mycorrhizal roots of C. argyrophylla, which were collected from a natural stand and an artificial stand, each grown at a different location. More mycorrhizal roots were found for trees from an artificial stand. The presence of extramatrical mycelium, mantle, and Hartig net revealed that C. argyrophylla formed an ectomycorrhizal association in both sampling sites. Starch granules were found in mycorrhizal roots collected only from a natural stand. The aseptic synthesis of C. argyrophylla and Cenococcum geophilum was established for the first time in vitro. Typical ectomycorrhizas formed on seedlings on RM medium containing 0.1 g/l glucose, 5 weeks after inoculation. By light microscopy, the synthesized mycorrhizas showed a thin mantle from which emanated extramatrical hyphae and highly branched Hartig net. A simple, rapid, and convenient mycorrhiza synthesis system was developed, which facilitates further studies on ectomycorrhizal development of C. argyrophylla.

Background: Gremmeniella abietina (Lagerb.) Morelet is an ascomycete fungus that causes stem canker and shoot dieback in many conifer species. The fungus is widespread and causes severe damage to forest plantations in Europe, North America and Asia. To facilitate early diagnosis and improve measures to control the spread of the disease, rapid, specific and sensitive detection methods for G. abietina in conifer hosts are needed., Results: We designed two pairs of specific primers for G. abietina based on the 18S rDNA sequence variation pattern. These primers were validated against a wide range of fungi and 14 potential conifer hosts. Based on these specific primers, two nested PCR systems were developed. The first system employed universal fungal primers to enrich the fungal DNA targets in the first round, followed by a second round selective amplification of the pathogen. The other system employed G. abietina-specific primers in both PCR steps. Both approaches can detect the presence of G. abietina in composite samples with high sensitivity, as little as 7.5 fg G. abietina DNA in the host genomic background., Conclusion: The methods described here are rapid and can be applied directly to a wide range of conifer species, without the need for fungal isolation and cultivation. Therefore, it represents a promising alternative to disease inspection in forest nurseries, plantations and quarantine control facilities.

Lyman glacier in the North Cascades Mountains of Washington has a subalpine forefront characterized by a well-developed terminal moraine, inconspicuous successional moraines, fluting, and outwash. These deposits were depleted of symbiotic fungi when first exposed but colonized by them over time after exposure. Four major groups of plant species in this system are (1) mycorrhiza-independent or facultative mycotrophic, (2) dependent on arbuscular mycorrhizae (AM) (3) dependent on ericoid mycorrhiza (ERM) or ectomycorrhizae (EM), and (4) colonized by dark-septate (DS) endophytes. We hypothesized that availability of mycorrhizal propagules was related to the success of mycorrhiza-dependent plants in colonizing new substrates in naturally evolved ecosystems. To test this hypothesis roots samples of 66 plant species were examined for mycorrhizal colonization. The plants were sampled from communities at increasing distances from the glacier terminus to compare the newest communities with successively older ones. Long established, secondary successional dry meadow communities adjacent to the glacier forefront, and nearby high alpine communities were sampled for comparison. DS were common on most plant species on the forefront. Nonmycorrhizal plants predominated in the earlier successional sites, whereas the proportion of mycorrhizal plants generally increased with age of community. AM were present, mostly at low levels, and nearly absent in two sites of the forefront. ERM were present in all species of Ericaceae sampled, and EM in all species of Pinaceae and Salicaceae. Roots of plants in the long established meadow and heath communities adjacent to the forefront and the high alpine community all had one or another of the colonization types, with DS and AM predominating.

Coarse woody debris is important for mycodiversity in forest ecosystems, but its availability in managed stands is reduced. Leaving dead wood during felling is suggested as an option to sustain and restore the diversity. However, little is known what fungi would colonise freshly cut wood left on managed sites, and how the colonisation process is influenced by ecological factors. During summer and autumn, 120 freshly cut Picea abies stem sections over 8 cm in diameter were placed upright in mapped locations over two discrete plots separated by 100 m in a north-temperate forest. After seven weeks the sections were collected, and isolation and identification of fungi was done from their upper surfaces. In all 943 fungal strains were isolated, representing 97 species. Species richness in the summer survey was 42.5% higher than during the autumn survey. Low species similarity characterized the different seasons (Sorensen indices: S(S) = 0.36 and S(N) = 0.34) and for 21 species (22%) observation frequency was significantly affected by season. As a result, community structures in summer and autumn differed notably (z-test; P < 0.001). Species richness between the two plots differed by less than 10%, but there were 64 species (66%) found only in one of them, thus qualitative similarity was low (S(S) = 0.49). Quantitative similarity was higher (S(N) = 0.63), indicating that the dominant species colonised wood to a similar extent in both areas. Fungal community structure differed significantly among the two plots (z-test; P < 0.001). Our data showed that freshly cut CWD contributed to mycodiversity in managed north-temperate forest, providing habitats for numerous individuals from over 100 species. The fungal community within a single stand differed markedly both across small distances and over the seasons. In order to sustain and enhance mycodiversity in managed stands. coarse wood should always be left during harvesting. This study also demonstrates the importance of molecular identification and ITS sequence databases for exploring fungal diversity in natural communities.