Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
Stud Mycol ; 95: 415-466, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32855744

RESUMEN

The newly discovered systematic placement of Bactrodesmium abruptum, the lectotype species of the genus, prompted a re-evaluation of the traditionally broadly conceived genus Bactrodesmium. Fresh material, axenic cultures and new DNA sequence data of five gene regions of six species, i.e. B. abruptum, B. diversum, B. leptopus, B. obovatum, B. pallidum and B. spilomeum, were studied. Bactrodesmium is a strongly resolved lineage in the Savoryellales (Sordariomycetes), supported by Bayesian and Maximum Likelihood methods. The genus Bactrodesmium is emended and delimited to hyphomycetes characterised by sporodochial conidiomata, mononematous often fasciculate conidiophores, holoblastic conidiogenesis and acrogenous, solitary, dry, pigmented, transversely or rarely longitudinally septate conidia. The conidia are seceding rhexolytically, exhibiting multiple secession patterns. An identification key to 35 species accepted in Bactrodesmium is given, providing the most important diagnostic characters. Novel DNA sequence data of B. longisporum and B. stilboideum confirmed their placement in the Sclerococcales (Eurotiomycetes). For other Bactrodesmium, molecular data are available for B. cubense and B. gabretae, which position them in the Dothideomycetes and Leotiomycetes, respectively. All four species are excluded from Bactrodesmium and segregated into new genera, Aphanodesmium, Gamsomyces and Kaseifertia. Classification of 20 other species and varieties not recognised in the genus is discussed. Based on new collections of Dematiosporium aquaticum, the type species of Dematiosporium, the genus is emended to accommodate monodictys-like freshwater lignicolous fungi of the Savoryellales characterised by effuse colonies, holoblastic conidiogenous cells and dictyosporous, pigmented conidia with a pore in each cell. Study of additional new collections, cultures and DNA sequence data revealed several unknown species, which are proposed as taxonomic novelties in the Savoryellales and closely related Pleurotheciales. Ascotaiwania latericolla, Helicoascotaiwania lacustris and Pleurotheciella erumpens are described from terrestrial, lentic and lotic habitats from New Zealand and France, respectively. New combinations are proposed for Helicoascotaiwania farinosa and Neoascotaiwania fusiformis. Relationships and systematics of the Savoryellales are discussed in the light of recent phylogenies and morphological patterns newly linked with the order through cultural studies.

2.
Planta Med ; 85(1): 62-71, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30016827

RESUMEN

In research focused on the discovery of new chemical diversity from freshwater fungi, a peak library was built and evaluated against a prostate cancer cell line, E006AA-hT, which was derived from an African American, as this population is disproportionately affected by prostate cancer. The chemical study of the bioactive sample accessioned as G858 (Delitschia sp.) led to the isolation of eight new α-pyrone derivatives (1:  - 7: , and 11: ), as well as the new 3S*,4S*-7-ethyl-4,8-dihydroxy-3,6-dimethoxy-3,4-dihydronaphthalen-1(2H)-one (15: ). In addition, the known compounds 5-(3-S-hydroxybutyl)-4-methoxy-6-methyl-2H-pyran-2-one (8: ), 5-(3-oxobutyl)-4-methoxy-6-methyl-2H-pyran-2-one (9: ), pyrenocine I (10: ), 5-butyl-6-(hydroxymethyl)-4-methoxy-2H-pyran-2-one (12: ), sporidesmin A (13: ), 6-ethyl-2,7-dimethoxyjuglone (14: ), artrichitin (16: ), and lipopeptide 15G256ε (17: ) were also obtained. The structures of the new compounds were elucidated using a set of spectroscopic (NMR) and spectrometric (HRMS) methods. The absolute configuration of the most abundant member of each subclass of compounds was assigned through a modified Mosher's ester method. For 15: , the relative configuration was assigned based on analysis of 3 J values. Compounds 1, 2, 5:  - 14, 16: , and 17: were evaluated against the cancer cell line E006AA-hT under hypoxic conditions, where compound 13: inhibited cell proliferation at a concentration of 2.5 µM.


Asunto(s)
Antineoplásicos/farmacología , Ascomicetos/química , Neoplasias de la Próstata/patología , Pironas/farmacología , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Agua Dulce/microbiología , Humanos , Masculino , Pironas/química , Pironas/aislamiento & purificación
3.
Sydowia ; 70: 129-140, 2018 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-30774163

RESUMEN

Two new species of Pleosporales, Anteaglonium rubescens (Anteagloniaceae) and Atrocalyx asturiensis (Lophiotremataceae), are described. Phylogenetic placement was determined by combined analyses of a DNA data matrix containing ITS, LSU, SSU, rpb2, and tef1. Anteaglonium rubescens is a stromatic fungus characterized by brown didymospores disarticulating within asci, and by the production of a red-orange to pink pigment produced in nature and in artificial culture. Atrocalyx asturiensis has massive ascomatal crests and brown phragmospores.

4.
Sydowia ; 69: 29-35, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29386694

RESUMEN

Stigmatodiscus pruni (Stigmatodiscaceae, Stigmatodiscales) is described and illustrated from corticated dead twigs of Prunus spinosa collected in Austria and France. It is characterised by hysteriform ascomata with two lateral black lips, which are erumpent through the periderm of the host, and a black disc in combination with two-celled, asymmetric brown verruculose ascospores with a distinct sheath. Phylogenetic analyses of a multigene matrix containing a representative selection of Dothideomycetes from four genes (nuc 18S rDNA, nuc 28S rDNA, rpb2 and tef1) revealed a highly supported placement within Stigmatodiscales as sister species to Stigmatodiscus enigmaticus. Micromorphology of the sexual and asexual morph matches the genus Stigmatodiscus, except for the hysteriform shape of the ascomata and the two-celled ascospores.

5.
Mycologia ; 107(4): 845-62, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26315030

RESUMEN

Minutisphaera is a recently established genus of freshwater Dothideomycetes characterized by small, globose to subglobose or apothecioid, erumpent to superficial, brown ascomata; fissitunicate, eight-spored, ovoid to obclavate asci; and 1-2-septate, clavate to broadly fusiform, hyaline to pale brown ascospores with or without a gelatinous sheath and filamentous appendages. The genus currently contains two species: M. fimbriatispora, the type species, and M. japonica. The higher-level phylogenetic relationship of Minutisphaera within the Dothideomycetes currently is unresolved. To establish the phylogenetic position of Minutisphaera within the Dothideomycetes and evaluate the phylogenetic affinities of newly collected Minutisphaera-like taxa, we sequenced three rDNA regions-18S, ITS1-5.8SITS2 (ITS) and 28S nuc rDNA, and a protein-coding gene, MCM7, for newly collected strains of Minutisphaera. Based on maximum likelihood and Bayesian analyses of a combined dataset (18S and 28S) composed of 167 taxa, a more refined dataset (28S and MCM7) comprising 52 taxa and a separate ITS dataset, and an examination of morphology, we describe and illustrate two new species of Minutisphaera. The Minutisphaera clade was strongly supported within the Dothideomycetes with likelihood and Bayesian statistics but did not share phylogenetic affinities with any existing taxonomic group within the Dothideomycetes. We therefore establish a new order, Minutisphaerales, and new family, Minutisphaeraceae, for this monophyletic clade of freshwater ascomycetes. Chemical analysis of the organic extract M. aspera (G427) resulted in isolation and characterization of five known secondary metabolites, of which four were dipeptides (1-4) and one an aromatic polyketide (5). Conversely, two aromatic polyketides (5, 6) were isolated and identified from the organic extract of M. parafimbriatispora (G156-4). The isolated compounds were tested for their antimicrobial activity against an array of bacteria and fungi. Compound 6 showed promising activity against Staphylococcus aureus and Mycobacterium smegmatis with minimal inhibitory concentration values of 30 and 60 µg/mL, respectively.


Asunto(s)
Ascomicetos/clasificación , Ascomicetos/aislamiento & purificación , Agua Dulce/microbiología , Sedimentos Geológicos/microbiología , Ascomicetos/genética , Ascomicetos/metabolismo , Biodiversidad , ADN de Hongos/genética , ADN Ribosómico/genética , Ecosistema , Hifa/genética , Hifa/crecimiento & desarrollo , Hifa/aislamiento & purificación , Datos de Secuencia Molecular , North Carolina , Filogenia , Policétidos/metabolismo , Esporas Fúngicas/genética , Esporas Fúngicas/crecimiento & desarrollo , Esporas Fúngicas/aislamiento & purificación
6.
Stud Mycol ; 77(1): 1-143, 2014 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-24790283

RESUMEN

For a monograph based on a polythetic concept, several thousands of herbarium specimens, and several hundreds of freshly collected and cultured specimens of Daldinia and allied Xylariaceae, originating from around the world, were studied for morphological traits, including by SEM, and chemically by HPLC profiles using UV-visible and mass spectrometric detection. Emphasis was given to tropical material, and importantly, ancient specimens, including as many types as possible, were tracked and studied to review earlier taxonomic concepts. An epitype of D. eschscholtzii was selected as representative of the morphochemotype that is most widely distributed in the tropics. Six new species of Daldinia from the tropics and the southern Hemisphere are described. Daldinia asphalatum is resurrected, and D. cudonia is regarded as its synonym. In addition, the following binomials are epi-, iso-, neo- and/or lectotypified: Daldinia asphalatum, D. caldariorum, D. clavata, D. cuprea, D. durissima, D. eschscholtzii, D. grandis, D. loculata, and D. vernicosa. Annellosporium and Versiomyces are regarded as synonyms of Daldinia. Many new synonymies in Daldinia are proposed, and some previously published names are rejected. In total, 47 taxa in Daldinia are recognised and a key is provided. Their biogeography, chorology, and ecology, as well as the importance of their secondary metabolites, are also discussed. The previous definition of the genus is emended. The species concept is based mainly on morphological and other phenotype-derived characters because, despite diligent search, no molecular data or cultures of several of the accepted species could be obtained. Daldinia is segregated into five major groups, based on phenotypic characteristics. Some unnamed but aberrant specimens were not found in good condition and are therefore not formally described as new species. However, they are illustrated in detail in a hope that this will facilitate the discovery of fresh material in future. A preliminary molecular phylogeny based on 5.8S/ITS nrDNA including numerous representatives of all hitherto described taxa for which cultures are extant, was found basically in agreement with the above mentioned segregation of the genus, based on morphological and chemotaxonomic evidence. In the rDNA based phylogenetic tree, Daldinia appears clearly distinct from members of the genera Annulohypoxylon and Hypoxylon; nevertheless, representatives of small genera of predominantly tropical origin (Entonaema, Phylacia, Ruwenzoria, Rhopalostroma, Thamnomyces) appear to have evolved from daldinioid ancestors and are nested inside the Daldinia clade. Interestingly, these findings correlate with chemotaxonomic characters to a great extent, especially regarding the distribution of marker metabolites in their mycelial cultures. Hence, the current study revealed for the first time that fungal secondary metabolite profiles can have taxonomic value beyond the species rank and even coincide with phylogenetic data. TAXONOMIC NOVELTIES: Daldinia andina sp. nov., D. australis sp. nov., D. hausknechtii sp. nov., D. rehmii sp. nov., D. starbaeckii sp. nov., D. theissenii sp. nov., D. cahuchosa comb. nov., D. nemorosa comb. nov.

7.
Mycologia ; 106(3): 505-24, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24871607

RESUMEN

In an ongoing effort to monograph the genus Lasiosphaeria, it is desirable to obtain estimates of the phylogenetic relationships for five uncommon species, L. coacta, L. munkii, L. punctata, L. sphagnorum and L. stuppea. Three additional species previously placed in Lasiosphaeria, Echinosphaeria canescens, Hilberina caudata and Ruzenia spermoides, also were included in this study as well as three undescribed species. These species were believed to have relations elsewhere based on various ambiguous morphological characters, so an independent dataset from one or more genes was used to resolve their phylogenetic affinities. Sequences from the nuclear ribosomal 28S large subunit (LSU) and ß-tubulin genes were generated for these taxa. Maximum likelihood and Bayesian analyses indicated these taxa form a well supported monophyletic group with members of the Helminthosphaeriaceae and therefore, should be transferred out of Lasiosphaeria. Except for Helminthosphaeria gibberosa, Hilberina elegans, Ruzenia spermoides and Synaptospora plumbea, all taxa within this clade possess ascomata with distinct thick-walled setae. Based on a combination of morphological and molecular data, Helminthosphaeria tomaculum, Helminthosphaeria triseptata and Hilberina robusta are described as new and four new combinations are proposed: Helminthosphaeria ludens, Hel. stuppea, Hilberina punctata and H. sphagnorum. Ten new combinations are proposed based on morphological data: Echinosphaeria heterostoma, Helminthosphaeria flavocompta, Hel. gibberosa, Hel. heterotricha, Hilberina breviseta, H. elegans, H. foliicola, H. meznaensis, H. moseri and H. rhynchospora. Lasiosphaeria coacta is placed in synonymy with Hel. ludens and the previous transfer of Hilberina munkii is accepted. Synaptospora plumbea was found to belong in the family. Illustrations are provided for most Helminthosphaeriaceae taxa seen in this study.


Asunto(s)
Ascomicetos/clasificación , Filogenia , Ascomicetos/genética , Ascomicetos/crecimiento & desarrollo , Ascomicetos/aislamiento & purificación , ADN de Hongos/genética , ADN Ribosómico/genética , Datos de Secuencia Molecular , Esporas Fúngicas/clasificación , Esporas Fúngicas/genética , Esporas Fúngicas/crecimiento & desarrollo , Esporas Fúngicas/aislamiento & purificación
8.
Mycologia ; 105(3): 603-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23233511

RESUMEN

During survey of freshwater fungi in Haute Garonne in the Pyrenees (southern France), we collected a remarkable species that is most comparable to the maritime fungus Mauritiana rhizophorae. The maritime genera Halotthia, Pontoporeia and Mauritiana as well as our newly collected species form a monophyletic clade in phylograms generated from LSU rDNA sequence analyses. This clade has undetermined familial status, and our new species is not congeneric with Halotthia, Pontoporeia or Mauritiana. A new monotypic genus, Phaeoseptum (represented by Ph. aquaticum sp. nov), therefore is introduced to accommodate the newly collected freshwater taxon. A new family, Halotthiaceae, is introduced to accommodate the four aquatic genera Halotthia, Mauritiana, Phaeoseptum and Pontoporeia.


Asunto(s)
Agua Dulce/microbiología , Saccharomycetales/clasificación , ADN Ribosómico/genética , Filogenia , Saccharomycetales/genética , Saccharomycetales/ultraestructura
9.
Bot Stud ; 64(1): 31, 2023 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-37891334

RESUMEN

BACKGROUND: The genus Camillea was created in 1849 from collections made in French Guiana with eight species included. Numerous species assigned to Camillea were subsequently discovered, especially in the forests of the Amazon basin, but new discoveries have not been reported from French Guiana since 1849. Recent fieldwork in French Guiana has begun to fill this gap by identifying five new species, most of which were collected in the vicinity of Saül village. RESULTS: Based on macro- and micromorphological study of their stromata, including SEM images of ascospore wall ornamentation, five new species were recognized, including C. cribellum, C. heterostomoides, C. nitida, C. rogersii and C. saulensis. Cultures could be obtained for C. heterostomoides and C. rogersii, and ITS and LSU sequences were obtained for all of the five new species. Camillea heterostoma and its variety microspora were shown to be conspecific. Provisional molecular phylogenetic analyses support the possible reinstatement of Hypoxylon melanaspis, currently regarded as merely an applanate form of C. leprieurii. CONCLUSION: The current study is based on a relatively limited fieldwork in its duration and sampling area but was able to substantially increase the number of Camillea species known from French Guiana. This augurs an exceptional and still unknown diversity of the genus in this area and by extension in the adjacent neotropical forests.

10.
Mycologia ; 104(6): 1299-314, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22684295

RESUMEN

Two strains of an unidentified perithecial ascomycete with a dactylaria-like anamorph and another morphologically similar strain of a dactylaria-like fungus were collected on decaying wood submerged in freshwater. To study their phylogenetic relationships we (i) combined sequence data from the nuclear small and large subunits ribosomal DNA (nc18S and nc28S) and the second largest subunit of RNA polymerase II (RPB2) for a multigene phylogenetic analysis and (ii) used sequences of the internal transcribed spacer region (ITS) of the rRNA operon for a species-level analysis. The new genus Pleurotheciella is described for two new species, Pla. rivularia and Pla. centenaria, with nonstromatic perithecia, unitunicate asci, persistent paraphyses and hyaline, septate ascospores and dactylaria-like anamorphs characterized by holoblastic, denticulate conidiogenesis, subhyaline conidiophores and hyaline, septate conidia. Based on morphological and molecular data, Pleurotheciella is closely related to the genera Pleurothecium and Sterigmatobotrys. A key to the three genera and the known species is provided. In the three-gene inferred phylogeny, these genera grouped as a sister clade to the Savoryellales within a robust clade of uncertain higher rank affiliation. Phylogenetic study of the 12 strains that represent Pleurothecium recurvatum revealed four that grouped apart from the core of the species. Two of these strains, which form a monophyletic well supported clade in both phylogenies and share similar morphological characteristics, are described as a new species, Pleurothecium semifecundum.


Asunto(s)
Ascomicetos/clasificación , ADN Ribosómico/genética , Proteínas Fúngicas/genética , Filogenia , Esporas Fúngicas/citología , Ascomicetos/citología , Ascomicetos/genética , Ascomicetos/aislamiento & purificación , Secuencia de Bases , ADN de Hongos/química , ADN de Hongos/genética , ADN Ribosómico/química , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Agua Dulce , Datos de Secuencia Molecular , Tipificación de Secuencias Multilocus , Técnicas de Tipificación Micológica , ARN Polimerasa II/genética , Análisis de Secuencia de ADN , Esporas Fúngicas/clasificación , Esporas Fúngicas/genética , Esporas Fúngicas/aislamiento & purificación , Madera/microbiología
11.
Mycologia ; 104(3): 766-76, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22314590

RESUMEN

Six penzigioid Xylaria species that are characterized by small, discoid to pulvinate, soft stromata are included in this study. Xylaria albocinctoides, X. bicampaniformis and X. lechatii are described as new; Nummularia albocincta, Hypoxylon carabayense and H. discolor are moved to the genus Xylaria to form new combinations X. albocincta, X. carabayensis and X. discolor respectively. An identification key is provided for the major aggregates of Xylaria that harbor penzigioid species as well as the species of the X. frustulosa aggregate, to which the six studied penzigioid Xylaria species belong.


Asunto(s)
Xylariales/clasificación , Xylariales/citología , ADN de Hongos/química , ADN de Hongos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Genes Fúngicos/genética , Micelio/genética , Alineación de Secuencia , Análisis de Secuencia de ADN , Especificidad de la Especie , Esporas Fúngicas/citología , Xylariales/genética , Xylariales/aislamiento & purificación
12.
Commun Biol ; 4(1): 871, 2021 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-34267314

RESUMEN

Fungal biotechnology is set to play a keystone role in the emerging bioeconomy, notably to address pollution issues arising from human activities. Because they preserve biological diversity, Biological Resource Centres are considered as critical infrastructures to support the development of biotechnological solutions. Here, we report the first large-scale phenotyping of more than 1,000 fungal strains with evaluation of their growth and degradation potential towards five industrial, human-designed and recalcitrant compounds, including two synthetic dyes, two lignocellulose-derived compounds and a synthetic plastic polymer. We draw a functional map over the phylogenetic diversity of Basidiomycota and Ascomycota, to guide the selection of fungal taxa to be tested for dedicated biotechnological applications. We evidence a functional diversity at all taxonomic ranks, including between strains of a same species. Beyond demonstrating the tremendous potential of filamentous fungi, our results pave the avenue for further functional exploration to solve the ever-growing issue of ecosystems pollution.


Asunto(s)
Biotecnología/métodos , Colorantes/metabolismo , Hongos/metabolismo , Microbiología Industrial/métodos , Lignina/metabolismo , Plásticos/metabolismo , Ascomicetos/clasificación , Ascomicetos/genética , Ascomicetos/metabolismo , Basidiomycota/clasificación , Basidiomycota/genética , Basidiomycota/metabolismo , Hongos/clasificación , Hongos/genética , Variación Genética , Geografía , Humanos , Fenotipo , Filogenia , Especificidad de la Especie
13.
Mol Phylogenet Evol ; 54(3): 957-69, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20035889

RESUMEN

To infer the phylogenetic relationships of Xylaria species associated with termite nests within the genus Xylaria and among genera of the subfamily Xylarioideae, beta-tubulin, RPB2, and alpha-actin sequences of 131 cultures of 114 species from Xylaria and 11 other genera of the subfamily were analyzed. These 11 genera included Astrocystis, Amphirosellinia, Discoxylaria, Entoleuca, Euepixylon, Kretzschmaria, Nemania, Podosordaria, Poronia, Rosellinia, and Stilbohypoxylon. We showed that Xylaria species were distributed among three major clades, TE, HY, and PO, with clade TE-an equivalent of the subgenus Pseudoxylaria-encompassing exclusively those species associated with termite nests and the other two clades containing those associated with substrates other than termite nests. Xylaria appears to be a paraphyletic genus, with most of the 11 genera submerged within it. Podosordaria and Poronia, which formed a distinct clade, apparently diverged from Xylaria and the other genera early. Species of Entoleuca, Euepixylon, Nemania, and Rosellinia constituted clade NR, a major clade sister to clade PO, while those of Kretzschmaria were inserted within clade HY and those of Astrocystis, Amphirosellinia, Discoxylaria, and Stilbohypoxylon were within clade PO.


Asunto(s)
Isópteros/microbiología , Filogenia , Xylariales/genética , Actinas/genética , Animales , Teorema de Bayes , ADN de Hongos/genética , Genes Fúngicos , Análisis de Secuencia de ADN , Tubulina (Proteína)/genética , Xylariales/clasificación
14.
MycoKeys ; 74: 17-74, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33149721

RESUMEN

The Chaetosphaeriaceae are a diverse group of pigmented, predominantly phialidic hyphomycetes comprised of several holomorphic genera including Chaetosphaeria, the most prominent genus of the family. Although the morphology of the teleomorphs of the majority of Chaetosphaeria is rather uniform, their associated anamorphs primarily exhibit the variability and evolutionary change observed in the genus. An exception from the morphological monotony among Chaetosphaeria species is a group characterised by scolecosporous, hyaline to light pink, multiseptate, asymmetrical ascospores and a unique three-layered ascomatal wall. Paragaeumannomyces sphaerocellularis, the type species of the genus, exhibits these morphological traits and is compared with similar Chaetosphaeria with craspedodidymum- and chloridium-like synanamorphs. Morphological comparison and phylogenetic analyses of the combined ITS-28S sequences of 35 isolates and vouchers with these characteristics revealed a strongly-supported, morphologically well-delimited clade in the Chaetosphaeriaceae containing 16 species. The generic name Paragaeumannomyces is applied to this monophyletic clade; eight new combinations and five new species, i.e. P. abietinus sp. nov., P. elegans sp. nov., P. granulatus sp. nov., P. sabinianus sp. nov. and P. smokiensis sp. nov., are proposed. A key to Paragaeumannomyces is provided. Using morphology, cultivation studies and phylogenetic analyses of ITS and 28S rDNA, two additional new species from freshwater and terrestrial habitats, Codinaea paniculata sp. nov. and Striatosphaeria castanea sp. nov., are described in the family. A codinaea-like anamorph of S. castanea forms conidia with setulae at each end in axenic culture; this feature expands the known morphology of Striatosphaeria. A chaetosphaeria-like teleomorph is experimentally linked to Dendrophoma cytisporoides, a sporodochial hyphomycete and type species of Dendrophoma, for the first time.

15.
Mycologia ; 101(2): 256-68, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19397200

RESUMEN

Xylaria hypoxylon, the type species of Xylaria (Xylariaceae, Sordariomycetes), was first described by Linnaeus as Clavaria hypoxylon from Sweden. Saccardo and other mycologists assumed a cosmopolitan distribution for this species. However, contradictory reports in the literature on its morphoanatomical characters and strongly inconsistent rDNA sequence data attributed to this species in GenBank suggested the existence of an unresolved species complex. To address this lack of clarity, molecular and morphological characters of numerous specimens and corresponding cultures of X. hypoxylon and related taxa from Europe were studied. Newly obtained 5.8S/ITS nrDNA sequence data were compared with published data and sequences of reference strains. European populations of X. hypoxylon from various hosts exhibited consistent rDNA sequence data and a relatively uniform holomorphic morphology, except for one specimen from Sweden that deviated in its ascospore morphology. Some samples from western United States showed DNA sequence data being identical to those of specimens from Europe, confirming a North American occurrence of X. hypoxylon. DNA sequences and morphology of other extra-European material however showed substantial deviations. Definitely not conspecific with the European material examined in this study is a strain, assigned to X. hypoxylon, the DNA sequence data of which have been used in various phylogenetic studies as a representative of Xylariaceae and Xylariales respectively. This material probably represents X longiana.


Asunto(s)
Ascomicetos , Ascomicetos/clasificación , Ascomicetos/citología , Ascomicetos/genética , ADN Espaciador Ribosómico/genética , Filogenia , Análisis de Secuencia de ADN
16.
Rev Iberoam Micol ; 23(3): 160-70, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17196023

RESUMEN

The Hypoxyloideae (Xylariaceae with Nodulisporium-like anamorphs) were evaluated by a morphological and HPLC-based chemotaxonomic survey of more than 2000 specimens and cultures. Conspecificity of recent records with ancient type specimens were established in many cases by HPLC, since their characteristic metabolites may remain stable for over 200 years. Most constitute novel natural products that were identified in the course of concurrent "mycochemical" studies. A comparison of HPLC profiles considering relationships within the Hypoxyloideae as inferred from the biogenesis of these pigments agreed fairly with concurrent molecular phylogenetic studies, based on sequences of actin, beta-tubulin, and 5.8S/ITS nrDNA genes. Anamorphic morphology and secondary metabolism of cultures agreed well at generic level and above. A combination of chemical and morphological traits is favored over PCR-based approaches for species discrimination, if only relatively few taxa of these diverse genera have been sequenced. An overview on the chemical structures and biological activities of the characteristic metabolites is provided, their ecological importance is discussed, and the utility of chemotaxonomy to support and predict phylogenetic relationships in the Hypoxyloidae is demonstrated. A polythetic approach is most useful to elucidate the phylogeny of the Xylariaceae. Chemotaxonomy to assess fungal biodiversity has considerable utility.


Asunto(s)
Pigmentos Biológicos/aislamiento & purificación , Xylariales/clasificación , Benzoatos/química , Benzoatos/aislamiento & purificación , Benzopiranos/química , Benzopiranos/aislamiento & purificación , Cromatografía Líquida de Alta Presión , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Proteínas Fúngicas/genética , Genes Fúngicos , Estructura Molecular , Naftalenos/química , Naftalenos/aislamiento & purificación , Filogenia , Pigmentos Biológicos/química , Reacción en Cadena de la Polimerasa , Resorcinoles/química , Resorcinoles/aislamiento & purificación , Terminología como Asunto , Tubulina (Proteína)/genética , Xylariales/química
17.
Phytochemistry ; 66(7): 797-809, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15797606

RESUMEN

Azaphilones, named cohaerins A and B were isolated from stromata of the xylariaceous ascomycete Hypoxylon cohaerens. Their absolute structures were determined by spectroscopic methods (2D NMR, MS, IR, UV CD), and subsequently confirmed by acetylation. Stromatal metabolite profiles of several taxa of Hypoxylon sect. Annulata were also generated using analytical HPLC with diode array and MS detection. The cohaerins were neither found in other Hypoxylon spp., nor in other Xylariaceae. However, they were present even in holotype material of H. cohaerens, collected over 200 years ago. The binaphthalene BNT was also omnipresent in sect Annulata, and its derivatives, the benzo[j]fluoranthenes daldinone A and truncatone, as well as presumably related compounds. These fungi were found devoid of other types of azaphilone pigments of the Xylariaceae, such as mitorubrins and daldinins, the latter of which are widespread in certain groups of Hypoxylon sect. Hypoxylon. Hence, chemotaxonomic data largely support the current generic concept. The original source of truncatone was identified as Hypoxylon annulatum.


Asunto(s)
Ascomicetos/metabolismo , Benzopiranos/aislamiento & purificación , Ascomicetos/química , Cromatografía Líquida de Alta Presión , Estructura Molecular
18.
IMA Fungus ; 5(1): 57-66, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25083407

RESUMEN

Although Xylaria hypoxylon is one of the most familiar fungi of temperate regions, the basionym of the name, Clavaria hypoxylon of Linnaeus, has remained untypified. Here we assess the original five elements included in the 1753 protologue; no candidate specimen was located but two illustrations Linnaeus cited were considered, one a mixture of species and the other fanciful. As the name is sanctioned, following clarifications in the Melbourne Code, elements cited by Fries when the name was sanctioned in 1823 are also candidates for lectotypification. In addition to various illustrations, Fries cites two exsiccatae, and one from his own Scleromycetes Suecicae distributed in 1821 is designated as lectotype for Linnaeus' name here. In view of the complexity of the group as revealed by molecular systematic work, and the poor state of the Fries material, we also designate a sequenced epitype from Sweden. We stress the importance of examining fungi in the complex in the sexual state, as those that are asexual can be difficult to identify conclusively. Figures of the original protologues and the most pertinent illustrations and specimens are provided, along with a detailed description and illustrations based on recent collections.

19.
Fungal Biol ; 118(2): 242-52, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24528645

RESUMEN

A new species of Hypoxylon was discovered, based on material collected in French Guiana and recognised on the basis of new combination of morpholological characters in comparison with type and authentic material of macroscopically similar taxa. These findings were corroborated by the rather isolated positions of its ITS-nrDNA and beta-tubulin DNA sequences in molecular phylogenies. However, the most salient feature of this fungus only became evident by a comparison of its stromatal HPLC profile, revealing several secondary metabolites that were hitherto not observed in stromata of any other member of the Xylariaceae. Part of the stromata were subsequently extracted to isolate these apparently specific components, using preparative chromatography. Five metabolites were obtained in pure state, and their chemical structures were elucidated by means of high resolution mass spectrometry and nuclear magnetic resonance spectroscopy. They turned out to be tetramic acid derivatives of the so-called vermelhotin type. Aside from vermelhotin, previously isolated from cultures of endophytic fungi, we identified three novel congeners, for which the trivial names hypoxyvermelhotins A-C were proposed. Like vermelhotin, they constitute orange-red pigments and a preliminary biological characterisation revealed them to have rather strong cytotoxic and moderate to weak antimicrobial effects. These results further illustrate the high diversity of unique secondary metabolites in stromata of the hypoxyloid Xylariaceae, a family in which biological diversity seems to parallel the chemical diversity of their bioactive principles to a great extent.


Asunto(s)
Pigmentos Biológicos/análisis , Pigmentos Biológicos/química , Xylariales/química , Xylariales/clasificación , Cromatografía Líquida de Alta Presión , Análisis por Conglomerados , ADN de Hongos/química , ADN de Hongos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Guyana Francesa , Datos de Secuencia Molecular , Estructura Molecular , Filogenia , Pirrolidinonas/análisis , Pirrolidinonas/química , Análisis de Secuencia de ADN , Tubulina (Proteína)/genética , Xylariales/genética , Xylariales/aislamiento & purificación
20.
Mycology ; 5(3): 110-119, 2014 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-25379335

RESUMEN

During the course of a screening for novel anti-infective agents from cultures of tropical Xylariaceae originating from French Guiana and Thailand, pronounced antifungal activity was noted in extracts of cultures of Hypoxylon monticulosum. A bioassay-guided fractionation led to the known metabolite sporothriolide as active principle. In addition, three new derivatives of sporothriolide were isolated, for which we propose the trivial names sporothric acid, isosporothric acid and dihydroisosporothric acid. Their chemical structures were elucidated by high-resolution electrospray mass spectrometry in conjunction with two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy. From earlier studies on the biogenesis of the chemically similar canadensolides, we postulate that the new compounds were shunt products, rather than biogenetic precursors of sporothriolide. Interestingly, this compound class, as well as strong antifungal activities, was only observed in multiple cultures of H. monticulosum, but not in several hundreds of Hypoxylon cultures studied previously or concurrently. Therefore, sporothriolide production may constitute a species-specific feature with respect to Hypoxylon and the Xylariaceae, although the compound was previously reported from non-related fungal taxa.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA