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1.
An undescribed ascomycete similar to species in the Aliquandostipitaceae (Jahnulales, Dothideomycetes) was collected from submerged wood in a freshwater swamp in Big Cypress National Preserve, Florida. The characteristic features of the new species are as follows: (i) ascomata are small, sessile, light brown, globose to subglobose, papillate, and anchored to the substrate by wide, brown, septate and subtending hyphae; peridial wall is composed of 1 to 2 layers of large, angular cells with large lumens; (ii) asci are ovoid to broadly clavate, and fissitunicate; (iii) ascospores are one-septate, fusiform, multiguttulate, pale brown, surrounded by a fusiform gelatinous sheath, and equipped with numerous filamentous appendages around the midseptum. The new fungus is most similar to Aliquandostipite crystallinus, from which it differs in overall smaller size and morphology. This new fungus is described and illustrated herein as A. minuta.  相似文献   

2.
Raja HA  Shearer CA 《Mycologia》2006,98(2):319-332
Three new species of loculoascomycetes collected from freshwater habitats in North America are described as new species of Jahnula (Jahnulales, Dothideomycetes). All three share these morphological features: hyaline to blackish translucent, membranous ascomata with subtending, wide, septate brown, spreading hyphae; peridia composed of large angular cells; hamathecium of septate pseudoparaphyses; 8-spored, clavate to cylindrical asci; and 1-septate, broadly fusiform, brown, multiguttulate ascospores. Four additional species, J. aquatica, J. bipolaris, J. potamophila, and J. seychellensis, are reported for the first time from the western hemisphere.  相似文献   

3.
In this study, we report the discovery of Jahnula dianchia sp. nov., a freshwater lignicolous fungus belonging to the order Jahnulales (Dothideomycetes, Ascomycota), from a submerged woody substrate from Dianchi Lake, Yunnan, China. Morphologically, this new taxon differs from other species of the genus in ascospore morphology; the ascospores of the new species are dark brown with mammiform apices. We also provide a phylogenetic tree showing the molecular relationships between the new taxon with the previously accepted Jahnula species. The analysis of combined ITS, LSU, and SSU sequence dataset places J. dianchia within the Jahnulales sister to J. sangamonensis. The phylogeny also shows the placement of both strains of J. dianchia in a well-supported independent sub-clade.  相似文献   

4.
Poroleprieuria gen. nov. is described and illustrated to accommodate P. rogersii in the Xylariaceae, Xylariales. This ascomycete, known only from the type collection, is characterized by reniform, light brown, smooth ascospores with a germ pore; cylindrical, persistent asci lacking an apical apparatus, septate persistent paraphyses, and erumpent, erect, dark brown, fragile, subcylindrical stromata. The characteristics of this xylariaceous fungus were compared with those of some other ascomycetes having superficially similar cylindrical stromata or ascospores with germ pores.  相似文献   

5.
从福建厦门市郊芒果园、南靖县鳞苞锥和广西玉林市郊巨尾按根区采集的土样中分离到一个球囊霉属的新种——长孢球囊霉。本文描述了该种的形态特征及生态环境。  相似文献   

6.
A new species of the endogonaceous fungus Gigaspora, isolated from the Indian semi-arid region, is described. The fungus, named G. tuberculata, produces rusty-brown azygospores with septate subtending hypha. The azygospores bear warts all over the outer wall. The shape, size and general appearance of these spores resemble those of Scutellospora persica.Neeraj and A.K. Varma are with the Microbiology Unit, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110 067, India; K.G. Mukerji is with the Applied Mycology Laboratory, Botany Department, University of Delhi, Delhi 110 006, India. B.C. Sharma is with the Department of Textile Engineering, Indian Institute of Technology, New Delhi 110 016, India.  相似文献   

7.
A new ascomycete species, Jahnula apiospora (Jahnulales, Dothideomycetes), collected from submerged wood in a freshwater creek on Prince Edward Island, Canada, is described and illustrated. The characteristic features of the new species are globose to subglobose, black, ostiolate, membranous ascomata with broad, brown, subtending hyphae; a peridial wall composed of an outer layer of thick-walled cells occluded by black, amorphous material along the upper two-thirds of the ascoma; trabeculate pseudoparaphyses; cylindrical to narrowly fusoid, fissitunicate asci; and brown, one-septate, apiosporous ascospores without a gelatinous sheath or appendages.  相似文献   

8.
In a study of the mycobiota associated with bark beetles, a dimorphic fungus producing longitudinally septate basidia of the Tremella-type and yeast cells budding off from stalks, was collected. Detailed morphological, physiological and molecular studies revealed that this fungus represents the teleomorph of Sterigmatosporidium polymorphum. Consequently, a new genus, Cuniculitrema gen. nov., and a new species, C. polymorpha sp. nov., are proposed. Comparative morphological and molecular studies indicated that the new taxon belongs to a group that also comprises species of the stalk-forming anamorphic genera Fellomyces and Kockovaella. The new family Cuniculitremaceae is proposed for this group.  相似文献   

9.
The effects of various carbon sources and of antibiotics on the morphology of hypha cells of the fungus Ustilago cynodontis is described. Nonfermentable substrates promote readily reversible yeastlike colonies from hypha cells: all the hypha cells spread on these substrates give rise to yeastlike colonies that revert to the mycelial phenotype when transferred to glucose medium. Among the antibiotics tested, chloramphenicol (CAP) is found to promote, under certain circumstances, a long-lasting, even permanent modification on the morphology of the colonies: the colonies developed on CAP-glucose media are yeastlike, and a percentage of them give rise to colonies whose morphology remains yeastlike even on drug-free media: this effect is also obtained with cells cultivated in liquid medium. This permanent morphological modification is accompanied by a change of metabolic properties. Similar permanent effects are obtained with ethidium bromide, suggesting that mitochondrial functioning is involved in these modifications.  相似文献   

10.
Sporidesmioides thailandica gen. et sp. nov., isolated from herbaceous litter in northern Thailand, is described and illustrated. The new genus is characterised by sporidesmium-like, septate, solitary, acrogenous, pale brown to brown, obclavate, conidia, which taper towards the apex and are truncate at the base and septate conidiophores similar to those of Sporidesmium species in Sporidesmiaceae (Sordariomycetes). It differs from similar genera by the presence of a stromatic base, polyblastic conidiogenous cells and a distinct, colourless sheath at the conidial apex. Phylogenetic analyses of combined LSU, SSU, TEF1-α and RPB2 sequence data show that the new taxon, Sporidesmioides thailandica, forms a separate, single clade with Torulaceae in Pleosporales, Dothideomycetes, and is distinct from Sporidesmiaceae (Sordariomycetes).  相似文献   

11.
The new genus and species Teracosphaeria petroica is described for a perithecial ascomycete and its anamorph occurring on decayed wood collected in New Zealand. The fungus produces immersed, non-stromatic ceratosphaeria-like perithecia in nature, with hyaline, septate ascospores produced in unitunicate, non-amyloid asci. The anamorph produced in vitro is phialophora-like with lightly pigmented phialides terminating in flaring, deep collarettes that are often noticeably brown with conspicuous periclinal thickening. Phylogenetic analysis of LSU rDNA sequence data indicates that this fungus is distinct from morphologically similar fungi classified in the Chaetosphaeriales, the Trichosphaeriales or the Magnaporthaceae. It forms a monophyletic group with recently described, chaetosphaeria-like ascomycetes, such as the pyrenomycete genus Mirannulata, and shows affinity with the anamorphic species Dictyochaeta cylindrospora. The usefulness of describing anamorph genera for morphologically reduced anamorphs, when anamorph characteristics are actually part of the holomorph diagnosis, is discussed. An apparently contradictory example of the so-called Cordana and Pseudobotrytis anamorphs of Porosphaerella spp. is also discussed.  相似文献   

12.
Colletotrichum gloeosporioides is an important pathogen that causes widespread brown spot disease on the leaves of the tea‐oil tree (Camellia oleifera) in China. This study was designed to isolate, identify and characterize this fungal pathogen, based on morphology, molecular characteristics and pathogenicity. One pathogenic fungus, named CCG4, was isolated from wild‐type Camellia oleifera of Hainan Province. Colonies were regular circular in shape with 50–60 mm diameter after 5 days of incubation at 28°C on potato dextrose agar (PDA) medium, and woolly with a small amount of jacinth pigment; the colony colour changed from white to black during later stages of infection. The mycelium produced was branched and septate. Conidia were cylindrical‐truncate, oblong‐obtuse to doliform, colourless with 1–2 hyaline oil globules and 4.5–5.3 μm × 7.7–17.5 μm. The sporodochia were cushion‐shaped. The pathogen was identified as Colletotrichum gloeosporioides on the basis of morphological characteristics and internal transcribed spacer sequence, which showed 100% query cover and 99% similarity to the sequence Colletotrichum gloeosporioides JN887341.1 , from a pathogenic fungus known to cause brown spot disease of Camellia oleifera.  相似文献   

13.
Nitrogen-fixing, field-obtained root nodules of the silky green alder were studied by transmission electron microscopy. The nodule endophyte exhibited a prokaryotic cytology and was present in two forms: the hypha(0.3-1.0mum), which was branched and septate, and the vesicle (3-5mum), which was also septate and developed at the parental hypha tip. Bacteria-like cells, previously observed in light microscopy studies, were not seen in the present work. The actinomycete-like endophyte penetrated through the host cell wall and becane enveloped by a capsular material (0.1mum), the whole being enclosed by host membranes. In some host cells, the endophyte appeared to lyse and become a mass of shrunken debris. The fine structure of the Alnus crispa var. mollis root nodule endophyte was found to be similar to that of other nonleguminous root nodule endophytes.  相似文献   

14.
Summary A hitherto unnoted species of Physoderma on the basal leaves of Juncus pelocarpus Mey. is described. The fungus produces light brown irregularlyplaced spots on the outermost leaves. The endobiotic system is composed in addition to rhizoids of non-septate or 1–2 septate turbinate cells, resting spores and ovate haustorial-bearing cells. Resting spores germinate by dehiscence of a lid and protrusion of a finger-like zoosporangium. No epibiotic stage has as yet been seen. The host range of the fungus has not as yet been studied. This is the first account of a Physoderma on a member of the Juncaceae.Acknowledgement is made to the National Science Foundation for support of this project.  相似文献   

15.
The present work describes the morphogenesis and cytological characteristics of 'branched absorbing structures' (BAS, formely named arbuscule-like structures, ALS), small groups of dichotomous hyphae formed by the extraradical mycelium of arbuscular mycorrhizal (AM) fungi. Monoxenic cultures of the AM fungus Glomus intraradices Smith & Schenck and tomato ( Lycopersicum esculentum Mill.) roots allowed the continuous, non-destructive study of BAS development. These structures were not observed in axenic cultures of the fungus under different nutritional conditions or in unsuccessful (asymbiotic) monoxenic cultures. However, extraradical mycelium of G. intraradices formed BAS immediately after fungal penetration of the host root and establishment of the symbiosis. The average BAS development time was 7 d under our culture conditions, after which they degenerated, becoming empty septate structures. Certain BAS were closely associated with spore formation, appearing at the spore's substending hypha. Branches of these spore-associated BAS (spore-BAS) usually formed spores. Electron microscopy studies revealed that BAS and arbuscules show several ultrastructural similarities. The possible role of BAS in nutrient uptake by the mycorrhizal plant is discussed.  相似文献   

16.
Abstract: A new fossil microfungus, Kryphiomyces catenulatus gen. et sp. nov., occurs as an endobiotic mycelial thallus in a large spore of a glomeromycotan fungus from the Lower Devonian Rhynie chert. The thallus consists of branched (?pseudo‐)septate hyphae with numerous catenulate swellings. Some hyphal tips produce spherical reproductive structures or propagules. Hyphal morphology in K. catenulatus is reminiscent of that in certain extant Hyphochytridiomycota, Chytridiomycota, and even Ascomycota, but specific diagnostic features that allow assignment of the fossil to modern groups are absent. The discovery of this interfungal association broadens our knowledge about the diversity of microfungi and their intricate associations in early continental ecosystems.  相似文献   

17.
Liverworts form diverse associations with endophytic fungi similar to mycorrhizas in vascular plants. Whereas the widespread occurrence of glomeromycotes in the basal liverwort lineages is well documented, knowledge of the distribution of ascomycetes and basidiomycetes in derived thalloid and leafy clades is more fragmented. Our discovery that the ramified and septate rhizoids of the Schistochilaceae, the sister group to all other ascomycete-containing liverworts, are packed with fungal hyphae prompted this study on the effects of the fungi on rhizoid morphology, host specificity, the cytology of the association, and a molecular analysis of the endophytes. Two species of Pachyschistochila and their fungi were grown axenically. Axenic rhizoids were unbranched and nonseptate. Reinfected with their own fungus and that from the other species, both Pachyschistochila species produced branched and septate rhizoids identical to those in nature. Woronin bodies and simple septa identified the fungus as an ascomycete referable, according to phylogenetic analyses of ITS sequences, to the Rhizoscyphus (Hymenoscyphus) ericae aggregate, also found in other liverwort-ascomycete associations and in mycorrhizas in the Ericales. Healthy hyphae and host cytoplasm suggest that the Schistochila-fungus association reflects a balanced mutualistic relationship. The recent dating of the divergence of the Jungermanniales from the fungus-free Porellales in the Permian and the origins of the Schistochilaceae in the Triassic indicate that these associations in liverworts predate the appearance of the Ericales.  相似文献   

18.
The genus Halosarpheia (Halosphaeriales) was established for marine ascomycetes with obpyriform to sub-globose, coriaceous, brown to black ostiolate ascomata with long necks; hamathecia of catenophyses; thin-walled, unitunicate, persistent asci with thick-walled apices; and ellipsoid, one septate, hyaline ascospores equipped with coiled, threadlike apical appendages that unfurl in water. Emphasis on ascospore appendage morphology has led to the inclusion in the genus of morphologically disparate fungi from a variety of marine and freshwater habitats. To better understand the evolutionary relationships of Halosarpheia species, phylogenetic analyses were conducted on 16 Halosarpheia species, 13 other species of Halosphaeriales and representatives of the Microascales, Hypocreales, Sordariales and Xylariales using 18S and 28S rDNA sequence data. All of the Halosarpheia species occurred on the Halosphaeriales clade. The type species of the genus, H. fibrosa, occurred on a well-supported clade with two morphologically similar species, H. trullifera and H. unicellularis. This clade, which phylogenetically was distant from the clades of other Halosarpheia species, represents the genus Halosarpheia sensu stricto. The other Halosarpheia species were distributed among eight other well-supported clades clearly separated from one another based on molecular data. New generic names are established for six of these clades, one new species is described, and one species is transferred to Aniptodera. A table (Table I) comparing the morphology, habitat, substrate and distribution of the genera of aquatic ascomycetes with coiled, threadlike apical appendages treated in this study is provided, along with a key for their identification.  相似文献   

19.
Phaeodiscus, a new genus of Sclerotiniaceae, is described with P. rhamnicola Batra as the single species. It is characterized by an ectal excipulum of subhyaline textura prismatica and textura porrecta; dichotomously branched, golden brown, aculeate paraphyses; and golden brown, narrowly ellipsoid, usually biguttulate ascospores. The two guttules fuse at maturity to form a single central guttule. The apothecia arise from pseudosclerotia consisting of numerous interconnected sclerotules. A number of other Sclerotiniaceae related to the new fungus are compared with it.  相似文献   

20.
Drechsler , Charles . (USDA, Plant Industry Sta., Beltsville, Md.) A new nematode-destroying hyphomycete of the genus Harposporium. Amer. Jour. Bot. 50(8): 839–842. Illus. 1963.—A mucedinaceous parasite that destroyed a largish nematode in a maize-meal-agar plate culture to which had been added some leaf mold from an oak wood in central Maryland is newly described as Harposporium dicorymbum. It permeates the host animal with colorless septate assimilative hyphae, 2.5-8.5 μ wide, that soon put forth procumbent septate conidiophores bearing mostly subglobose phialides with 1-3 sterigmata. Its very distinctive conidia are composed of a minutely pedicellate globose part, 4-7 μ in diameter, together with a cylindrical outgrowth, 3-9 μ long and 2-3 μ wide, which is furnished distally with a short posterior and a longer anterior beak.  相似文献   

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