Fusarium fractiflexum sp. nov. and two other species within theGibberella fujikuroi species complex recently discovered in Japan that form aerial conidia in false heads

Morphological and molecular phylogenetic analyses were conducted on 12 strains ofFusarium, deposited in MAFF asF. subglutinans (≡F. moniliforme var.subglutinans≡F. sacchari var.subglutinans) orFusarium sp. because they formed aerial conidia in false heads in the dark. These strains were resolved as three distinct species within theGibberella fujikuroi species complex. A new species,F. fractiflexum, and two species new to Japan,F. circinatum andF. concentricum, are described and illustrated and their morphological features are discussed.Fusarium fractiflexum, isolated from diseased yellow leaf spots ofCymbidium spp., is differentiated from other fusaria based on its yellowish colonies and aerial conidia formed in false heads in the dark and in zigzag-like conidial chains under black light. Japanese strains ofF. circinatum also formed elongate, coiled sterile hyphae. Phialidic aerial conidia with a pointed apex and a wedgeshaped base were found inF. concentricum cultured under black light and represent a new diagnostic character of the species, in addition to colonies with alternating concentric rings when cultured on PDA. Based on DNA sequences of the β-tubulin gene and two other loci, strains ofF. fractiflexum were resolved phylogenetically as members of the Asian clade of theG. fujikuroi species complex. In addition, Japanese strains ofF. circinatum andF. concentricum were phylogenetically identical to the ex-type strains.     

Effect ofAspergillus parasiticus soil inoculum on invasion of peanut seeds

Environmental control plots adjusted to late season drought and elevated soil temperatures where inoculated at peanut planting with low and high levels of conidia, sclerotia, and mycelium from a brown conidial mutant ofAspergillus parasiticus. Percentage infection of peanut seeds from undamaged pods was greatest for the subplot containing the high sclerotial inoculum (15/cm² soil surface). Sclerotia did not germinate sporogenically and may have invaded seeds through mycelium. In contrast, the mycelial inoculum (colonized peanut seed particles) released large numbers of conidia into soil. Soil conidial populations of brownA. parasiticus from treatments with conidia and mycelium were positively correlated with the incidence of seed infection in undamaged pods. The ratio ofA. flavus to wild-typeA. parasiticus in soil shifted from 7:3 to 1:1 in the uninoculated subplot after instigation of drought, whereas in all subplots treated with brownA. parasiticus, the ratio of the two species became approximately 8:2. Despite high levels of brownA. parasiticus populations in soil, nativeA. flavus often dominated peanut seeds, suggesting that it is a more aggressive species. Sclerotia of wild-typeA. parasiticus formed infrequently on preharvest peanut seeds from insect-damaged pods.     

Dactylella chichisimensis, sp. nov. in the Bonin (Ogasawara) Islands, Japan

ADactylella isolate obtained from soil in the Bonin (Ogasawara) Islands, Japan is described and illustrated as a new species,D. chichisimensis. The fungus is characterized by single terminal multiseptate clavate or ellipsoidal conidia at the apex of simple conidiophores and mycelium that forms chlamydospores and sclerotia. A key is provided for sixDactylella species that produce primary clavate or ellipsoidal conidia at the apex of simple conidiophores.     

Fusarium kyushuense sp. nov. from Japan

Four trichothecene-producing strains originally isolated from diseased wheat and a vinyl plate in Kyushu and Shikoku, Japan are described and illustrated as a new species,Fusarium kyushuense. This species does not produce chalamydospores, which is the key morphological character which distinguishes it fromF. sporotrichioides with which it has been mistaken.Fusarium kyushuense is also differentiated from another morphologically similar species,F. arthrosporioides, by absence of sclerotia and by differences in conidiogenesis of obovate, conidia. InF. arthrosporioides conidia are partly holoblastic from the aerial conidiophores and mostly phialidic from the sporodochial conidiophores, while inF. kyushuense conidia are mostly holoblastic and only produced from aerial conidiophores.     

Materials for the fungus flora of Japan (56)Mariannaea camptospora andM. elegans var.punicea from Japan

One additional species and a variety ofMariannaea, M. camptospora andM. elegans var.punicea, were recorded for the first time in Japan.Mariannaea camptospora formed two types of conidiophores. One type was characterized by simple verticillate phialides sometimes with punctuate walls at the base, producing long oblique conidial chains, and symmetrical spindle-shaped conidia. The other type was characterized by more crowded and shorter phialides with small conidial droplets and hemispherical to concave smaller conidia.Mariannaea elegans var.punicea was characterized by distinct red purple pigmentation in agar media. (55): Udagawa, S. and Uchiyama, S., Mycoscience41: 263–267, 2000.     

Carbohydrate and lipid components of hyphae and conidia of human pathogenFonsecaea pedrosoi

The carbohydrate and lipid components of mycelium and conidia ofFonsecaea pedrosoi (Brumpt) were analysed by paper, thin-layer and gas-chromatography, mass spectrometry and ultraviolet spectroscopy. Glucose, mannose, galactofuranose, rhamnose and glucosamine were polysaccharide components identified inF. pedrosoi. Significant changes in the carbohydrate pattern occurred during the conversion of mycelium into conidia. Rhamnose was predominant in conidia whereas galactose was prominent in mycelium. Palmitic, stearic, oleic, linoleic, and arachidonic acids were the fatty acids identified in the total lipid fraction. Palmitic and oleic acids were major fatty acids. Marked alterations in the fatty acid constituents were observed between the cell types ofF. pedrosoi. Arachidonic acid was detected only in conidia and linoleic acid was preferentially identified in mycelium. Differences in the sterol composition was also associated with morphogenesis inF. pedrosoi. Two main sterols, ergosterol and another less polar sterol, not fully characterized, were found in mycelium whereas in conidia only the latter sterol was present.     

分离自蜻蜒虫草的拟青霉属一新种

本文描述了拟青霉属(Paecilomyces)一新种—蜻蜓拟青霉(P. odonatae),该菌分离自蜻蜓虫草(Cordyceps odonatae),与其它种的典型区别特征是它具有拟青霉型产孢结构,产椭圆形链状排列的分生孢子和枝顶孢霉型产孢结构,产柱状粘成团排列的分生孢子.     

Five additional genera of conidial lichen-forming fungi from Europe

Three remarkable new genera of conidial lichen-forming fungi, with pycnidial or acervular conidiomata are described and illustrated.Hastifera tenuispora gen. et spec. nov. from the South-Tyrol, Italy, is characterized by very long and narrow hyaline conidia produced in pycnidial conidiomata immersed in thalline warts.Lichingoldia gyalectiformis gen. et spec. nov. from rocks subject to inundation by freshwater in Norway has long sigmoidly curved conidia which appear to be adapted to dispersal in water.Woessia fusarioides gen. et spec. nov. from aQuercus stump in the Burgenland, Austria, has a finely granular thallus and disc-like conidiomata producing falcate conidia; this species is also of interest in that it hasChlorella as the photobiont. The recently described hyphomyceteCheiromycina flabelliformis B. Sutton is reported from Austria for the first time, and is also lichenized. Recent collections ofNigropuncta rugulosa D. Hawksw. from Austria and Italy also show that this species is lichenized rather than parasymbiotic. In all five cases the fungal hyphae of the conidiogenous structures are continuous with those in intimate contact with cells of the algal partners and the biological relationship appears to be mutualistic giving rise to stable crustose lichen thalli.     

Production ofBeauveria bassiana [Deuteromycotina: Hyphomycetes] in different liquid media and subsequent conidiation of dry mycelium

Mycelium ofBeauveria bassiana can be grown in liquid culture, filtered, and the mycelium dried. After rehydration the mycelium sporulates. Two carbohydrate sources (sucrose and maltose), and one nitrogen/vitamin source (yeast extract) were tested for mycelium growth and subsequent conidial production. Maximum mycelium growth (12.31 mg/ml), in liquid culture, was in the sucrose (3.5%)/yeast extract (3.5%) medium, but mycelium from a maltose (2%)/yeast extract (0.75%) medium produced the maximum of 4.62×10⁶ conidia/mg dry mycelium after incubation in moist Petri dishes. Using the data on mycelium yield (in liquid culture) and conidial production (by dry mycelium) it is calculated that the sucrose (3.5%)/yeast extract (3.5%) and the maltose (2%)/yeast extract (0.75%) media produce most conidia per media volume (an equivalent of 3.52–3.72×10⁷ conidia/ml).      

Acremonium-like submerged conidiation inPaecilomyces nostocoides andP. lilacinus

Paecilomyces nostocoides, in which conidia of smaller or larger sizes appear in chains, was newly isolated from Japan. In addition to the typicalPaecilomyces-type conidiation, the Japanese isolate showed additionalAcremonium-like submerged conidiation in and/or on some agar media. The submerged conidiation was also observed in the ex-type strains, but not in the type specimens ofP. nostocoides. The same submerged conidiation was observed inP. lilacinus, the species most similar toP. nostocoides. The species definitions ofP. nostocoides andP. lilacinus were emended to include the submerged conidiation.Paecilomyces-type conidia were uninucleate in bothP. nostocoides andP. lilacinus. Paecilomyces nostocoides andP. lilacinus had the Q-10(H₂) ubiquinone system.     

Fungal Infection of Mantis Shrimp (<Emphasis Type="Italic">Oratosquilla oratoria</Emphasis>) Caused by Two Anamorphic Fungi Found in Japan

Two fungal pathogens of the mantis shrimp (Oratosquilla oratoria) in Yamaguchi and Aichi Prefectures, Japan are described as the new species Plectosporium oratosquillae and Acremonium sp. (a member of the Emericellopsis marine clade). Both fungi infect the gills of the mantis shrimp, which become brown or black due to melanization. The former species is characterized by its slow growth on artificial seawater yeast extract peptone glucose (PYGS) agar, pale yellow to pale orange or grayish yellow colonies, short cylindrical solitary phialides with a wavy tip, and one-celled ellipsoidal conidia. Although lacking the two-celled conidia demonstrated by the type species Plectosporium tabacinum, the taxonomic placement of the new species was confirmed by DNA sequence analysis of the internal transcribed spacer (ITS) region of ribosomal DNA (ITS1, 5.8S rDNA and ITS2). Acremonium sp., the other causal pathogen, differs from P. oratosquillae by its fast growth on PYGS agar, pale orange to salmon-colored colonies, long, slender conidiophores consisting of solitary phialides with tips lacking an undulate outline, and typically cylindrical conidia. Analysis of ITS and β-tubulin gene sequences placed this fungus within the phylogenetically distinct Emericellopsis (anam. Acremonium) marine clade. Various physiological characteristics of both pathogens were also investigated. This is the first report of a fungal infection found on the mantis shrimp in Japan.     

Peculiarities of Exogenous Dormancy of Aspergillus nigerConidia

Aspergillus nigerconidia are characterized by exogenous dormancy: the first stage of their germination is accomplished in twice-distilled water. However, germ tube formation requires the availability of carbon and nitrogen sources. Exogenous dormancy in A. nigerconidia exhibits the following peculiar features: (i) nitrogen-containing substances are active stimulators of germination; (ii) temperature-dependent changes in the lipid bilayer and in the neutral lipid composition of conidia are virtually identical to those occurring in growing mycelium under temperature stress; and (iii) the spore viability threshold does not exceed 45°C; i.e., the spores are more heat-resistant than the mycelium, but they are less heat-resistant than the spores that are in the state of endogenous dormancy. According to the current classification of the types of cell metabolism arrest, the exogenous dormancy of A. nigerconidia resembles the pattern of metabolism characteristic of vegetative cells during the idiophase.     

Brown spot ofRheum officinale in indonesia with special reference to the variation in conidia of the causal fungus

Brown spot disease ofRheum officinale, a traditional medicinal plant in South East Asia, was newly recorded from the highland area of West Java Province. After confirmation of its pathogenicity towardRheum officinale and comparison of its morphology with hitherto known species, the casual fungus was identified asAscochyta rhei. It produces widely varied conidia from unicellular and bacillar conidia (Phoma-type), 1-septate oblong conidia (Ascochyta-type) to 2–3-septate cylindric conidia. These conidia were sometimes formed within the same pycnidium. They could germinate easily and produce the similar colonies to each other. Supported by “Joint Study Project for Strengthening Research on Diseases of Industrial Crops in Indonesia, Japan International Cooperation Agency (JICA)” in BALITTRO.     

Influence of the culture medium composition on the excreted/secreted proteases from <Emphasis Type="Italic">Streptomyces violaceoruber</Emphasis>

Streptomyces violaceoruber produces two different classes of mycelium, the substrate and the aerial mycelium. Since proteases have been associated with morphological turnover processes in other Streptomyces species, the presence of excretory/secretory proteolytic activities was investigated here in S. violaceoruber culture supernatants. Various polypeptide bands, with apparent molecular masses ranging from 40 to 180 kDa, were detected in soy trypticase broth (STB) culture media supernatants following 72 h of growth, using Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Zymograms showed the presence of five proteolytic enzymes (Spvio1–5), which migrated as bands of 167.7, 130.7, 110.7, 48.3 and 40.9 kDa, respectively. The characterization of these proteases by specific inhibitors showed that Spvio1–4 belong to the serine protease group and Spvio5 corresponds to a cysteine protease. Additionally, Spvio2 and 5 were inhibited by a mixture of EDTA and EGTA, indicating that both require divalent cations. The protease pattern obtained in STB enriched with glucose was identical to that obtained in STB. However, Spvio3 and 4 were absent when nitrogen was added to the culture medium. Cell death was fluorescently detected following 72 h of S. violaceoruber growth in STB and in STB that was enriched with glucose. On the contrary, no cell death was detected in nitrogen-enriched STB media. Additionally, the formation of the aerial mycelium was impaired in solid cultures of STB media enriched with nitrogen. These results demonstrate that the composition of the media influences the morphological turnover of the colony and the pattern of excreted/secreted proteases from S. violaceoruber, and suggest that Spvio3 and 4 are involved in the aerial mycelium formation.     

Infection of Sentinel Cotton Aphids (Homoptera: Aphididae) by Aerial Conidia ofNeozygites fresenii(Entomophthorales: Neozygitaceae)

Uninfected adultAphis gossypii(Homoptera: Aphididae) apterae (sentinel aphids) on cotton leaves were exposed for 8 h to the air over a commercial cotton field in Louisiana during the night of 1–2 July 1995. At 0015 h there were 90,437 primary conidia/m³air of the fungusNeozygites fresenii(Entomophthorales: Neozygitaceae) at the midfield position as determined from Rotorod samples. Forty-eight percent (n = 106) of the sentinel aphids exposed for 8 h at midfield were infected by aerial conidia ofN. fresenii.Exposure of sentinel aphids outside the cotton field, at 10 and 100 m downwind and 10 m upwind, resulted in 34.8% (n = 131), 24.0% (n = 129), and 17.4% (n = 146) infected aphids, respectively. These data demonstrate that wind-dispersed aerial conidia ofN. freseniiare infective and rapidly and efficiently disperse the pathogen throughout aphid populations within and between fields.     

A New Basidiomycetous Yeast Species, Cryptococcus mycelialis, Related to Holtermannia Saccardo et Traverso

A new species of the genus Cryptococcus, Cr. mycelialis (the type strain VKM Y-2863), is described based on the taxonomic study of four strains isolated from soil and plant samples collected on the South Georgia and East Falkland islands. This species differs from the known Cryptococcus species in its ability to form a true monokaryotic mycelium with pseudoclamp connections and haustoria. The species can be distinguished from the phylogenetically related and phenotypically similar species Holtermannia corniformis and Cr. nyarrowii by some assimilatory reactions, maximum growth temperature, and sensitivity to mycocins.     

Isolation and characterization of melanin pigment from <Emphasis Type="Italic">Pleurotus cystidiosus</Emphasis> (telomorph of <Emphasis Type="Italic">Antromycopsis</Emphasis><Emphasis Type="Italic">macrocarpa</Emphasis>)

Melanins are enigmatic pigments that are produced by a wide variety of microorganisms including several species of bacteria and fungi. For more than 40 years, fungi have been known to produce pigments called melanins. Melanin pigment production by mushrooms was not intensively studied. The present study was carried out on isolation and characterization of melanin from an edible mushroom Pleurotus cystidiosus var. formosensis. The mushroom produced dark mucous mass of hyaline arthrospores on mycelium. The coremia exclusively produced dikaryotic arthrospores with the remnant of a clamp connection. Continuous cell extension and division in the coremium stipe supplied cells for arthroconidiation at the coremium apex, which is surrounded by a liquid droplet (coremioliquid). The black coloured coremea (conidia) were produced by Antromycopsis macrocarpa (anamorph of P. cystidiosus) when cultured on potato dextrose agar medium. The agar plate was incubated at continuous light illumination for high amount of pigment (coremea) production. The slimy layer of the coremea was extracted and partially purified by alkaline and acid treatment. The black pigment was confirmed as melanin based on UV, IR and EPR spectra apart from chemical analysis. This is the first report on characterization of melanin obtained from Pleurotus cystidiosus var. formosensis.     

Susceptibility of Brevipalpus phoenicis to entomopathogenic fungi

The pathogenicity of 52 isolates from several fungus species was studied for the false spider mite Brevipalpus phoenicis. In addition, the main stages during the course of infection by Hirsutella thompsonii, by far the most virulent pathogen, were studied by means of light and electron microscopy. Adult mites were confined to arenas prepared with citrus leaves in acrylic dishes containing agar–water. Conidial suspensions containing 10⁸ conidia/ml were applied, except for H. thompsonii, where a concentration of 10⁷ conidia/ml was used. The H. thompsonii isolates caused higher mortality, with indices higher than 90%. Observations under the scanning electron microscope (SEM) were performed at 0, 6, 12, 24, 48, 72, and 120 h after application of a H. thompsonii suspension containing 10⁷ conidia/ml. Twenty-four hours after inoculation, H. thompsonii conidia were observed attached to the mite’s integument. The conidia germinated and penetrated through the base of the setae on the hysterosoma. Colonization occurred after 48 h, as evidenced by mortality. Conidiogenesis occurred after 120 h, with the development of mycelium and conidiophores emerging from the posterior and anterior parts of the mite.