新着情報

Mycoscience 50巻1号 (2009年1月号) 掲載論文要旨
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総説： Reproduction and dispersal in aquatic hyphomycetes

Felix Bärlocher

Department of Biology, Mount Allison University, 63B York Street, Sackville, NB, Canada E4L 1G7

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 world-wide 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.
Mycoscience 50 (1), 2009, pp. 3-8.
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総説： Saprotrophic cord systems: dispersal mechanisms in space and time

Lynne Boddy 1), Juliet Hynes 1), Daniel P. Bebber 2), Mark D. Fricker 2)

1) Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3US, UK
2) Department of Plant Science, University of Oxford, South Parks Road, Oxford OX1 3RB, UK

In natural terrestrial environments nutrients are often patchily and sparsely distributed and 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 metres or even hectares), long-lived (many years) systems. These mycelial systems form effective dispersal mechanisms in space and time. This paper 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 colonizes those resources; (2) to grow and search 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 colonized, is explored using techniques borrowed from graph theory and statistical mechanics.
Mycoscience 50 (1), 2009, pp. 9-19.
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総説： The living strategy of nematophagous fungi

Xingzhong Liu, Meichun Xiang, Yongsheng Che

Key Laboratory of Systematic Mycology & Lichenology, Institute of Microbiology, Chinese Academy of Sciences, 3 Datun Road, Chaoyang District, Beijing 100101, China

The infection structures, trophism, and ecological characters of nematophagous fungi are reviewed in this paper on the basis of data extracted from the literatures and the most recent experiments conducted in this area. Traditionally, nematophagous fungi are classified into four groups according to their modes to attack nematodes: nematode-trapping fungi using adhesive or mechanical hyphal traps, endoparasitic fungi using their spores, egg-parasitic fungi invading nematode eggs or females with their hyphal tips, and toxin-producing fungi immobilizing nematodes prior to invasion. In present review, we focus on the first two groups. The living strategies of these nematophagous fungi depend on the diversity of infection structures, such as different traps and spore types, which determine the modes of infection to 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 environment factors. Comprehensive understanding of survival and activity of nematophagous fungi in soil is fundamental for the exploitation of these fungi as successful biocontrol agents.
Mycoscience 50 (1), 2009, pp. 20-25.
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総説： 雪腐病菌の低温適応

星野 保 1,2)，肖 楠 1,2)，Oleg B Tkachenko 3)

1) 産業技術総合研究所ゲノムファクトリー研究部門  〒062-8517 北海道札幌市豊平区月寒東2-17-2-1
2) 北海道大学大学院理学院  〒060-0810 北海道札幌市北区北10西8
3) The Main Botanical Garden named after N.V. Tsitsin, Russian Academy of Sciences, 4 Botanicheskaya Ulitsa, 127276 Moscow, Russia

雪腐病菌は，積雪下に越冬する植物に対して病原性を示す好冷性または耐冷性糸状菌の総称である．雪腐病菌は，積雪下で成長，宿主への感染が可能であり，このため細胞内外の酵素は低温で活性を示す．また，耐冷性・凍結耐性は，雪腐病菌の地理分布に重要な要素であり，担子菌類は，不凍タンパク質を細胞外に分泌し，その機能は生育環境の凍結防止と推定される．好冷性子嚢菌であるSclerotinia borealis（雪腐大粒菌核病菌）では-1℃，凍結した寒天培地上の生育が，未凍結寒天培地上の生育至適温度による培養よりも優れていた．本菌の持つこの性質は，土壌凍結を指標とする極寒の環境に適応した結果と推察される．本総説においては，分類学的に異なる雪腐病菌がそれぞれ異なる方法で積雪下の低温条件にどのように適応しているか，その機構を概説した．
Mycoscience 50 (1), 2009, pp. 26-38.
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総説： アンモニア菌の増殖戦略

鈴木 彰

千葉大学教育学部  〒263-8522 千葉市稲毛区弥生町1-33

アンモニア菌は多量のアンモニウム態窒素施与によって撹乱された林床に速やかに侵入する．アンモニア菌の潜在形態は胞子と極小さい菌糸体あるいはそのいずれかと思われる．アンモニア菌は，弱塩基性―中性でアンモニウム態窒素が存在する条件下で急速に胞子発芽する特性を有している．各アンモニア菌は，アンモニウム態窒素による撹乱後に他の同地生息微生物の競争能が抑制されている間にテリトリーを獲得する．遷移前期のアンモニア菌 (EP菌) は，土壌のアンモニウム態窒素濃度の低下に伴うpHの低下によって非アンモニア菌の増殖が盛んになる前に胞子を形成する．遷移後期のアンモニア菌（LP菌）の菌根菌は，アンモニウム態窒素による撹乱で非アンモニア菌の増殖・競争能が抑制されている間に，LF層でのEP菌との競合を回避してHA層に菌根を形成する．菌根性アンモニア菌はアンモニウム態窒素による撹乱で土壌が高pHの間，アンモニウム態窒素を資化するが，同撹乱が弱くなるとアンモニウム態窒素と硝酸態窒素の両者を資化する．増殖前略からみると，早期EP菌はruderal stress-tolerant戦略者，晩期EP菌はcombative ruderal戦略者，LP菌は他のアンモニア菌との相互作用という観点からはcombative戦略者である．
Mycoscience 50 (1), 2009, pp. 39-51.
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短報： 内生菌による脱リグニンが菌類によるヤブツバキ落葉の分解に及ぼす影響

大園享司 1)，広瀬 大 2)

1) 京都大学大学院農学研究科  〒606-8502 京都市左京区北白川追分町
2) 筑波大学菅平高原実験センター  〒386-2204 長野県上田市菅平高原1278-294

内生菌であるCoccomyces sp.によるヤブツバキ落葉の先行分解が，Coccomyces sp.自身および後続の2種の落葉分解菌Dermateaceae sp.，Xylaria sp. (anamorph) による落葉分解に及ぼす影響を，純粋培養条件下での分解試験により調べた．Coccomyces sp.による先行分解は，これら3種によるその後の分解を促進した．Coccomyces sp.の先行分解に続けてDermateaceae sp.による分解を受けた落葉や，Dermateaceae sp.のみによる先行分解を受けた落葉では，Dermateaceae sp.はほとんど分解力を示さなかった．これに対してXylaria sp. (anamorph) では，これら2タイプの落葉において炭水化物の利用可能性が低下していたにも関わらず，分解の促進が認められた．
Mycoscience 50 (1), 2009, pp. 52-55.
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短報： サイコクカマアシムシ（カマアシムシ目，六脚類）から分離された新種Hirsutella proturicola

栗原祐子 1)*，白水 貴 2)，徳増征二 2)，原山重明 1)

1) (独) 製品評価技術基盤機構バイオテクノロジー本部  〒292-0818 千葉県木更津市かずさ鎌足2-5-8
2) 筑波大学菅平高原実験センター  〒386-2204 長野県上田市菅平高原1278-294
* 現所属: (有) オーピーバイオファクトリー石垣ラボ  〒907-0002 沖縄県石垣市真栄里567-5

土壌動物サイコクカマアシムシ（カマアシムシ目，六脚類）から分離したHirsutella属の新種，H. proturicolaを記載した．Hirsutella proturicolaは単生で24-(39)-51.5×2.5-(3)-5 μm，頸部がやや粗面のフィアライド，湾曲した紡錘形で9-(15)-18×2.5-(3)-4 μm，切形の基部及びしばしば鞘状の粘性物質を被る乳頭状の突起を持つ分生子と，多細胞性で21-(36)-48×21-(32.5)-41.5 μm，球形から亜球形の厚壁胞子を形成するという特徴を持つ．本種は形態的・系統的にダニ病原菌であるH. rostrataに類似するが，フィアライドの大きさと分生子の形態・大きさによって区別できる．
Mycoscience 50 (1), 2009, pp. 56-62.
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資料： マツ材線虫病の微害林分と激害林分における外生菌根と菌根性子実体

鵜川 信 1)，市原 優 2)，福田健二 3)，鈴木和夫 4)

1) 森林総合研究所立地環境研究領域  〒305-8687 茨城県つくば市松の里1
2) 森林総合研究所東北支所  〒020-0123 岩手県盛岡市下厨川字鍋屋敷92－25
3) 東京大学大学院新領域創成科学研究科自然環境学専攻  〒277-8563 千葉県柏市柏の葉5-1-5
4) 森林総合研究所  〒305-8687 茨城県つくば市松の里1

材線虫病の激害林分1箇所と微害林分2箇所において，外生菌根の形態観察，菌根性子実体の発生調査および土壌調査を行った．活性根端に占める外生菌根の割合は，微害林分と激害林分で有意な差がみられなかった．全根端に占める活性根端（外生菌根を含む）の割合は，1つの微害林分で激害林分よりも有意に高い結果が得られたが，他方の微害林分では激害林分との間に有意な差は認められなかった．激害林分では，微害林分に比べ，シーノコッカム(Cenococcum geophilum) の優占度が著しく高かった．菌根性子実体の種数は，激害林分で著しく低かった．
Mycoscience 50 (1), 2009, pp. 63-69.
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資料： Changes in quality of Phellinus gilvus mushroom by different drying methods

Woo-Sik Jo 1), So-Deuk Park 1), Seung-Chun Park 2), Zhi-Qiang Chang 2), Geon-Sik Seo 3), Jae-Youl Uhm 4), Hee-Young Jung 4)

1) Department of Agricultural Environment, Gyeongbuk Agricultural Technology Administration, Daegu 702-708, Korea
2) College of Veterinary Medicine Kyungpook National University, Daegu 702-701, Korea
3) Department of Industrial Crops, Korea National Agricultural College, Hwasung 441-893, Korea
4) College of Agriculture and Life Sciences, Kyungpook National University, Daegu 702-701, Korea

This study was conducted to investigate the changes in characteristics of Phellinus gilvus mushroom as influenced by drying methods after harvested. The lowest weight loss rate of P. gilvus mushroom showed that 75.8% of drying in the shade and 80% of dryer (60℃). The size loss rate of pileus was 19.3% of hot wind dryer (60℃). The hardness of dried material’s context by a hot wind dryer (60℃) was the lowest (20 ㎏/㎠), and that by a dry oven (60℃), was the highest (457 ㎏/㎠). For △E value, 4.9 of context, 2.6 of tubes using dry in the shade (20℃) were found the lowest. The survival rate of sarcoma 180 treated with P. gilvus dried in the sun was the lowest (51.8%), and it was considered the most effective method on antitumor activity against sarcoma 180.
Mycoscience 50 (1), 2009, pp. 70-73.
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資料： 日本新産の2種のハラタケ型菌，Pluteus magnus とPluteus podospileus f. podospileus

竹橋誠司 1)，糟谷大河 2)

1) NPO法人北方菌類フォーラム  〒006-0041 札幌市手稲区金山1-3-10-3
2) 筑波大学生命環境科学研究科  〒305-8572 つくば市天王台1-1-1

2種のウラベニガサ属菌，Pluteus magnus （新称和名：トゲウラベニガサ）およびP. podospileus f. podospileus （新称和名：ザラツキウラベニガサ）を日本新産種として記録した．これら2種の肉眼的，顕微鏡的特徴を記載・描画した．
Mycoscience 50 (1), 2009, pp. 74-77.
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資料： Influence of Flammulina velutipes mycelia culture conditions on antimicrobial metabolites production

Marcelo Rodrigues de Melo 1), Luzia Doretto Paccola-Meirelles 1), Terezinha de Jesus Faria 2), Noemia Kazue Ishikawa 1)*

1) Departamento de Biologia Geral, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Caixa Postal 6001, Londrina, Paraná, 86051-990, Brazil
2) Departamento de Química, Centro de Ciências Exatas, Universidade Estadual de Londrina, Caixa Postal 6001, Londrina, Paraná, 86051-990, Brazil
* 現住所: Coordenação de Pesquisas em Tecnologia de Alimentos, Instituto Nacional de Pesquisas da Amazônia, Av. André Araújo, 2936, Manaus, Amazonas – CEP: 86060-020, Brazil

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 the 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 in the complete Pontecorvo’s culture medium. Environmental modifications, such as a rise in temperature from 25º to 37ºC 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 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 correlation between culture medium composition and Enokipodins biosynthesis.
Mycoscience 50 (1), 2009, pp. 78-81.