Mycoscience
Online ISSN : 1618-2545
Print ISSN : 1340-3540
Volume 50, Issue 1
Displaying 1-11 of 11 articles from this issue
Review
  • Felix Bärlocher
    2009 Volume 50 Issue 1 Pages 3-8
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    The conidia of aquatic hyphomycetes were discovered by C.T. Ingold some 60 years ago. They are typically multiradiate or sigmoid, relatively fragile, and produced in enormous numbers. Their main function seems to be the rapid colonization of a periodic superabundance of leaves common in most streams. Conidia are unlikely to survive adverse conditions and to be responsible for the apparently worldwide distribution of many aquatic hyphomycete species. It has repeatedly been suggested that meiospores are responsible for long-distance dispersal; however, to date, only some 10% of described species have been connected to a teleomorph. To determine additional connections, and to document the potential role of meiospores in long-distance dispersal of aquatic hyphomycetes, the application of modern molecular methods is essential.

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  • Lynne Boddy, Juliet Hynes, Daniel P. Bebber, Mark D. Fricker
    2009 Volume 50 Issue 1 Pages 9-19
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    In natural terrestrial environments, nutrients are often patchily and sparsely distributed, and the microclimate is constantly changing both temporally and spatially. To survive, fungi must be able to transfer to a new resource before the nutrient supplies in their current food base are exhausted. While the majority of fungi propagate as spores, some basidiomycetes can grow out of a resource as mycelium in search of new resources. The mycelium of these fungi typically aggregates to form linear organs, termed cords or rhizomorphs, that ramify at the soil–litter interface in forests, interconnecting disparate litter components to form extensive (many square meters or even hectares), long-lived (many years) systems. These mycelial systems form effective dispersal mechanisms in space and time. This article reviews the two main, but not mutually exclusive, mycelial dispersal (resource capture) strategies: (1) a “sit and wait” strategy, whereby a large mycelial network waits for resources to land on it and then actively colonises those resources; and (2) growing and searching actively for new resources. The way in which mycelia balance exploration and nutrient transport, and robustness to damage, against “cost” of production and speed with which an area can be colonised, is explored using techniques borrowed from graph theory and statistical mechanics.

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  • Xingzhong Liu, Meichun Xiang, Yongsheng Che
    2009 Volume 50 Issue 1 Pages 20-25
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    The infection structures, trophism, and ecological character of nematophagous fungi are reviewed in this article on the basis of data extracted from the literature and the most recent experiments conducted in this area. Traditionally, nematophagous fungi are classified into four groups according to their modes of attacking nematodes: nematode-trapping fungi using adhesive or mechanical hyphal traps, endoparasitic fungi using their spores, eggparasitic fungi invading nematode eggs or females with their hyphal tips, and toxin-producing fungi immobilizing nematodes before invasion. In the present review, we focus on the first two groups. The living strategies of these nematophagous fungi depend on the diversity of their infection structures, such as different traps and spore types, which determine the modes of infecting nematodes. The diversity of trophic modes of nematophagous fungi is an important prerequisite for fungal survival and activity in soil. The abundance and activity of Hirsutella rhossiliensis and H. minnesotensis, representatives of endoparasites and potential biocontrol agents against nematodes, are highly dependent on environmental factors. Comprehensive understanding of the survival and activity of nematophagous fungi in soil is fundamental for the exploitation of these fungi as successful biocontrol agents.

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  • Tamotsu Hoshino, Nan Xiao, Oleg B. Tkachenko
    2009 Volume 50 Issue 1 Pages 26-38
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    Snow molds are psychrophilic or psychrotrophic fungal pathogens of forage crops, winter cereals, and conifer seedlings. These fungi can grow and attack dormant plants at low temperatures under snow cover. In this review, we describe the biodiversity and physiological and biochemical characteristics of snow molds that belong to various taxa. Cold tolerance is one of the important factors related to their geographic distribution, because snow molds develop mycelia under snow cover and because they should produce intra- and extracellular enzymes active at low temperatures for growth and infection. Basidiomycetous snow molds produce extracellular antifreeze proteins. Their physiological significance is to keep the extracellular environment unfrozen. The psychrophilic ascomycete Sclerotia borealis shows normal mycelial growth under frozen conditions, which is faster than that on unfrozen media at optimal growth temperature. This fungus does not produce extracellular antifreeze proteins, but osmotic stress tolerance enables the fungus to grow at subzero temperatures. In conclusion, different taxa of snow molds have different strategies to adapt under snow cover.

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  • Akira Suzuki
    2009 Volume 50 Issue 1 Pages 39-51
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    Ammonia fungi invade forest floors immediately after a enrichment disturbance by a large input of ammonium-nitrogen. Latent form(s) of the ammonia fungi are spores and/or mycelium fragments. Ammonia fungi are characterized by their rapid germination stimulated by the presence of ammonium-nitrogen under neutral to weakly alkaline conditions. Each ammonia fungus establishes its territory during suppressed combative abilities of other microbes following ammonium-nitrogen disturbance. Earlyphase ammonia fungi (EP fungi) quickly sporulate before nonammonia fungi colonize with the declining of ammonium- nitrogen concentration associated with descending pH. Ectomycorrhizal species of late-phase ammonia fungi (LP fungi) escape from the L-F horizon as a result of interactions between EP fungi and form mycorrhizae in the H-A horizon when other fungal activities are suppressed by the ammonium-nitrogen disturbance. Ectomycorrhizal ammonia fungi initially use ammonium-nitrogen when the pH rises because of the ammonium-nitrogen disturbance and then gradually utilize both ammonium- and nitrate-nitrogen when the effects of the ammonium-nitrogen disturbance weaken. Early-stage EP fungi are ruderal stress-tolerant strategists whereas late-stage EP fungi are combative ruderal strategists. LP fungi are combative strategists from the standpoint of the interactions between other ammonia fungi. This classification is based on differences in their respective propagation strategies.

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Short communication
  • Takashi Osono, Dai Hirose
    2009 Volume 50 Issue 1 Pages 52-55
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    Effects of prior decomposition of Camellia japonica leaf litter by an endophytic phyllosphere fungus Coccomyces sp. on the subsequent decomposition of the litter by Coccomyces sp. and two succeeding fungi Dermateaceae sp. and Xylaria sp. (anamorph) were examined in a pureculture decomposition test. The prior decomposition of litter by Coccomyces sp. stimulated the subsequent decomposition by the three fungi. Dermateaceae sp. caused negligible weight loss on litter previously partly decomposed by Coccomyces sp. and then by Dermateaceae sp. and on litter decomposed singly by Dermateaceae sp. Xylaria sp. (anamorph) caused greater weight loss in these litters than control, uninoculated litter.

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  • Yuko Kurihara, Takashi Shirouzu, Seiji Tokumasu, Shigeaki Harayama
    2009 Volume 50 Issue 1 Pages 56-62
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    A new species of Hirsutella, H. proturicola, isolated from a subterranean proturan (Baculentulus densus; Protura, Hexapoda), is described and illustrated. Hirsutella proturicola is characterized by producing monoblastic phialides of 24–51.5×2.5–5μm with a slightly roughened neck, fusiform and curved conidia of 9–18×2.5–4μm that have a truncate base and a papillate projection often capped with sheath-like mucilage, and pluricellular, globose to subglobose chlamydospores of 21–48×21–41.5μm. This species is morphologically and phylogenetically close to H. rostrata, an acaropathogenic species, but can be distinguished from the size of the phialides and the size and shape of the conidia.

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Note
  • Shin Ugawa, Yu Ichihara, Kenji Fukuda, Kazuo Suzuki
    2009 Volume 50 Issue 1 Pages 63-69
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    We surveyed ectomycorrhizae, ectomycorrhizal fungal fruit bodies, and soil physical properties in one heavily damaged and two lightly damaged pine stands on Mt. Tsukuba, central Japan. The rate of ectomycorrhizal root tips was not different between heavily and lightly damaged pine stands. For ectomycorrhizae, Cenococcum geophilum had high relative abundance in the heavily damaged pine stand. The number of ectomycorrhizal fungal fruit bodies in the heavily damaged pine stand was much lower than that in the lightly damaged pine stands.

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  • Woo-Sik Jo, So-Deuk Park, Seung-Chun Park, Zhi-Qiang Chang, Geon-Sik S ...
    2009 Volume 50 Issue 1 Pages 70-73
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    This study was conducted to investigate the changes in characteristics of the Phellinus gilvus mushroom as influenced by drying methods after harvest. The lowest weight loss rate of P. gilvus mushroom was 75.8% with drying in the shade and 80% by dryer (60°C). The size loss rate of pileus was 19.3% of that in a hot air dryer (60°C). The hardness of dried material context using a hot air dryer (60°C) was the lowest (20kg/cm2), and that by a dry oven (60°C) was the highest (457kg/m2). For ΔE value, 4.9 of context and 2.6 of tubes using drying in the shade (20°C) were found to be the lowest. The survival rate of sarcoma 180 treated with P. gilvus dried in the sun was the lowest (51.8%), and this was considered the most effective method for antitumor activity against sarcoma 180.

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  • Seiji Takehashi, Taiga Kasuya
    2009 Volume 50 Issue 1 Pages 74-77
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    Two taxa of the genus Pluteus, i.e., Pluteus magnus and Pluteus podospileus f. podospileus, are newly recorded from Japan. The macroscopic and microscopic features of these two species are described and illustrated.

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  • Marcelo Rodrigues Melo, Luzia Doretto Paccola-Meirelles, Terezinha de ...
    2009 Volume 50 Issue 1 Pages 78-81
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    Enokipodins A, B, C, and D are α-cuparene-type sesquiterpenoids antimicrobial metabolites produced in the stationary stage of Flammulina velutipes mycelia development in malt extract broth. This study assessed the influence of nutritional and environmental factors on F. velutipes mycelia culture for the production of these metabolites. The mycelia growth and antimicrobial activity were assessed by determining dry matter and the diffusion in agar method, respectively. The best F. velutipes mycelia growth was observed in dextrose potato broth, and greater antimicrobial metabolite production occurred in complete Pontecorvo's culture medium. Environmental modifications, such as a rise in temperature from 25° to 37°C on the 15th day of F. velutipes mycelia culture in malt extract and peptone broth, also optimized antimicrobial metabolite production. The metabolites produced in these treatments were correlated with the enokipodins A and B in thin-layer chromatography (TLC) and the antifungal activity test by TLC bioautography. This study showed that there was no correlation between biomass production and antimicrobial metabolite production, but there may be a correlation between culture medium composition and enokipodins biosynthesis.

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