Mycoscience
Online ISSN : 1618-2545
Print ISSN : 1340-3540
Volume 50, Issue 4
Displaying 1-10 of 10 articles from this issue
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  • Yousuke Degawa
    2009Volume 50Issue 4 Pages 247-252
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL FREE ACCESS

    Orchesellaria (Orc.) mauguioi (Asellariales) was detected from the hindguts of Isotomurus palustris (Collembola, Hexapoda) collected in Japan. The secondary spore formation on the exuviae of its host is described. When the host molted, its exoskelton including the ectoderm-originated hindgut cuticle to which Orc. mauguioi mycelia attaches was shed. Arthrospores of Orc. mauguioi germinated and penetrated the molt skin and produced secondary spores terminally. The secondary spore is a narrowly ovoid monosporangious sporangium accompanied by a capitate-lageniform terminal cell; these fall off together as a dispersive unit. The terminal cell is sterile and bears one to three fine filamentous extensions seven times as long as the length of the cell. In contrast to the appendages produced endogenously by other harpellids, the filament is produced exogenously and is similar to those of the genus Orphella (Harpellales). The taxonomic and ecological implications of the secondary spore formation of Orc. mauguioi are discussed by comparison with those of other Trichomycetes.

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  • Kazunari Takahashi, Yoshio Hada
    2009Volume 50Issue 4 Pages 253-260
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL FREE ACCESS

    The relationship between myxomycete species and the decay stage of wood of Pinus densiflora coarse woody debris was investigated in warm temperate secondary forests of western Japan. The number of species and species diversity of the myxomycete community reached the maximum on moderately decayed wood. The 25 dominant species recorded from 8 or more samples of the total 1530 samples were arranged in order of the succession index corresponding to the stage of decay. Species on slightly decayed hard pine wood were characterized by Stemonitis splendens, Enerthenema papillatum, and Physarum viride, whereas species of Cribrariaceae were found on brittle decayed soft wood increasing abundance according to the decay stages. Most of the species occurred where there was sufficient moisture preserved in the environment of the decaying wood, although S. splendens specifically emerged in low-moisture environments. Because the myxomycete species had preference to different decay stages of wood, it appears that they change sequentially during myxomycete community succession on dead pine wood according to the progression of decay.

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  • Sayaka Ban, Takeshi Sakane, Kyoko Toyama, Akira Nakagiri
    2009Volume 50Issue 4 Pages 261-272
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL FREE ACCESS

    Based on morphological characteristics and molecular phylogeny, we reclassified Cordyceps cuboidea and allied species C. alboperitheciata, C. prolifica, and Ophiocordyceps ryogamiensis. We investigated their teleomorph- anamorph relationships and revealed that these four species have Hirsutella-like anamorphs with morphological differences between them. By analyzing their molecular phylogeny, inferred from DNA sequences of internal transcribed spacer (ITS) and large subunit (LSU) D1/D2 region of rDNA, they were separated into four close-knit clades. Although C. prolifica and O. ryogamiensis formed their own clades, isolates of C. cuboidea separated into two clades, i.e., a true C. cuboidea clade and one resembling a new species, the O. paracuboidea clade. The latter two species are distinguished by the fruiting region of the stroma. In addition, C. alboperitheciata is regarded as a synonym of C. cuboidea. From the morphology, teleomorph-anamorph relationships, and molecular phylogeny, we concluded these species should be assigned to the genus Ophiocordyceps.

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  • Jouji Moriwaki, Takao Tsukiboshi
    2009Volume 50Issue 4 Pages 273-280
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL FREE ACCESS

    Five isolates of a species of Colletotrichum were collected from Japanese barnyard millet (Echinochloa utilis) in Japan. Although the fungus had once been identified as C. graminicola sensu lato, it was clearly different from C. graminicola isolated from maize (Zea mays) in its falcate and short conidia, 18.0–22.2μm in length, cultural characteristics, and specific pathogenicity to E. utilis. Moreover, molecular phylogenetic analyses using sequences of rDNA-ITS, HMG, and SOD2 indicated a monophyly of the isolates. A new species, Colletotrichum echinochloae, is then proposed based on the morphological, pathological, and molecular characteristics.

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  • Shihomi Uzuhashi, Motoaki Tojo, Sakura Kobayashi, Makoto Kakishima
    2009Volume 50Issue 4 Pages 281-290
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL FREE ACCESS

    During a survey of Pythium species in soils of Japan, Pythium isolates growing at high temperatures were obtained from an uncultivated field soil in Wakayama Prefecture. All six isolates showed similar morphology to each other and had complexly branched secondary hyphae, globose nonproliferating sporangia, and smooth-surfaced oogonia that have one or two oospores per oogonium. The combination of these characteristics differentiated these isolates from other Pythium species reported. Phylogenetic analyses based on sequences of the ribosomal DNA ITS and D1/D2 region of the large subunit showed that all Pythium isolates were clustered in a single clade that was distantly related to other known clades of the genus. We described these isolates as a new Pythium species, Pythium apinafurcum, based on morphology and molecular phylogeny. The P. apinafurcum isolates nonsymptomatically infected the roots of seedlings of bermudagrass, cabbage, and cucumber in a pot inoculation test.

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  • Keiichi Motohashi, Shigeki Inaba, Kozue Anzai, Susumu Takamatsu, Chiha ...
    2009Volume 50Issue 4 Pages 291-302
    Published: 2009
    Released on J-STAGE: March 31, 2023
    JOURNAL FREE ACCESS

    Although the genus concept of Phyllosticta s. str. (teleomorph: Guignardia) as defined by van der Aa is widely accepted, the species concept is still controversial because it is often based on the morphology on host plants. In this study, the culture characteristics within Phyllosticta s. str. were examined, and the phylogenetic relationships among Japanese species of Phyllosticta s. str. and its teleomorph Guignardia were analyzed using 18S rDNA sequences. Phyllosticta s. str. formed a monophyletic clade. ITS-28S rDNA sequences extracted from fungal cultures derived from various host plants were divided into two subgroups. The first group included cultures from a wide range of host plants and were mainly derived as endophytes from a symptom-less plant. In the second group, cultures from each host plant genus formed distinct clades; these were often isolated as leaf pathogens from diverse plants. Isolates belonging to the first lineage generally grew faster on oatmeal agar. To classify species of Phyllosticta it is necessary to consider an integrated approach such as molecular phylogeny, host plant, colony growth, symptoms, and morphological characteristics of the conidiomata.

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