Showing papers in "Mycologia in 2000"
TL;DR: The complex historical biogeography of this complex appears to reflect vicariant events associated with the fragmentation of Gondwanaland, possible gondwanic range expansions together with relatively recent distributional changes in these fungi associated with movement of economically important plants.
Abstract: Phylogenetic relationships and biogeography of the phytopathogenic Nectria haematococca-Fusarium solani species complex, section Martiella of Fusarium, were inferred from sequence data from the nuc...
398 citations
TL;DR: The nucleotide sequences of the nuclear ribosomal DNA including 18S, 5.8S, and 28S rDNA and the internal transcribed spacer regions were determined for 33 powdery mildew taxa spanning 15 genera to ...
Abstract: The nucleotide sequences of the nuclear ribosomal DNA including 18S, 5.8S, and 28S rDNA and the internal transcribed spacer regions were determined for 33 powdery mildew taxa spanning 15 genera to ...
211 citations
TL;DR: This molecular phylogenetic analysis at both the ordinal and generic levels provides strong evidence for the recognition of the Saprolegniomycetidae and the Peronosporomy- cetidae as natural groups, and for the monophyly of the saprolegniales, Leptomitales and Pythiales.
Abstract: The evolutionary history of the mitochondrial COX2 locus has been used to infer the phylogenetic relationships among 15 peronosporomycete and a hyphochytriomycete species This molecular phylogenet
174 citations
TL;DR: The annual Lolium (ryegrass) species were surveyed for seedborne, asexual Epichloe endophytes (i.e., Neotyphodium spp.).
Abstract: The annual Lolium (ryegrass) species were surveyed for seedborne, asexual Epichloe endophytes (i.e., Neotyphodium spp.). Endophytes that were extremely slow growing in culture were identified from ...
160 citations
TL;DR: Utilization of major forms of carbon, nitrogen and phosphorus commonly present in plant litter and detritus was determined for cultures of Phialophora finlandia, Phialocephala fortinii and five dar...
Abstract: Utilization of major forms of carbon, nitrogen and phosphorus commonly present in plant litter and detritus was determined for cultures of Phialophora finlandia, Phialocephala fortinii and five dar...
158 citations
TL;DR: The white-rot fungus Pycnoporus sanguineus produces laccase under a range of C/N ratios in submerged liquid culture and was identified as a ca 65 kDa protein produced as multiple isoforms.
Abstract: The white-rot fungus Pycnoporus sanguineus produces laccase under a range of C/N ratios in submerged liquid culture. Enzyme production was increased 50 fold in the presence of 20 μM xylidine to a m...
152 citations
TL;DR: The phylogenetic relationships of 67 iso- lates representing 24 species of Pythium were assessed by sequence alignment of 684 bp of the mitochon- drially-encoded cytochrome oxidase II gene and the evolutionary relationships obtained by analysis of cox II DNA sequence data corresponds well with the genomic location of this mitochondrially encoded gene.
Abstract: The phylogenetic relationships of 67 iso- lates representing 24 species of Pythium were assessed by sequence alignment of 684 bp of the mitochon- drially-encoded cytochrome oxidase II gene. Se- quence differences among species ranged 1.6-14.7% substitutions. The species grouped into three major clades that were, in a general sense, reflective of zoos- porangial or hyphal swelling morphology. Clade I contained species with globose to spherical zoospo- rangia or spherical hyphal swellings. Clade II was comprised of four species, only one of which pro- duced zoosporangia (P. ultimum var. sporangiiferum) with the remaining species producing only spherical hyphal swellings. Species with filamentous to lobulate zoosporangia were in clade III. Pythium oligandrum, a species that produces subglobose zoosporangia with interconnecting filamentous parts was intermediate between species with inflated to lobulate filamentous zoosporangia and species that produced spherical to globose zoosporangia (clades I and II). Two species that produced globose zoosporangia (P pulchrum and P rostratum) grouped together separately from the other clades, as did P. nunn. The evolutionary relationships among species obtained by analysis of cox II DNA sequence data corresponds well with the genomic location of this mitochondrially encoded gene as well as the location of the nuclear encoded 5S rRNA gene for a subset of species examined. Char- acteristics such as heterothallism, oogonial ornamen- tation, mycoparasitism and the presence of linear mi- tochondrial genomes were polyphyletic. The only species that contained isolates that did not group to- gether were P ultimum and P irregulare, possible rea- sons for this are discussed.
148 citations
TL;DR: The abundance of polymorphisms makes the AFLP technique more suitable to distin- guish organisms in clusters of closely related species and at the isolate level, and the fungal phylogenetic relationships were not in disagreement with the ITS-derived tree.
Abstract: We have compared the use of DNA se- quences from the genomic internal transcribed spac- er (ITS) ribosomal RNA region, with a newer meth- od, the amplified fragment length polymorphism (AFLP) technique. ITS sequences encompass only a small part of the genome but normally reveal suffi- cient variability to distinguish isolates at the genus and often the species level. Although the AFLP tech- nology reveals genome-wide restriction fragment length polymorphisms, it has not been employed ex- tensively in establishing phylogenetic relationships. We have adapted the AFLP technology for fungal ge- nomes and compared AFLP fingerprints generated from several fungal species and isolates from the or- der Ustilaginales: Ustilago hordei, U. nigra, U. aegilop- sidis, U. avenae, U. kolleri, U. bullata, U. nuda, U. tritici, U. maydis, U. scitaminea, Sporisorium reilianum, and Tilletiales: Tilletia indica and T walkeri. Geo- graphical isolates of U. hordei and related species, particularly those infecting small-grain cereals, were difficult to distinguish when comparing ITS sequenc- es, but were clearly separated when comparing AFLP fingerprints. The abundance of polymorphisms makes the AFLP technique more suitable to distin- guish organisms in clusters of closely related species and at the isolate level. Phylogenetic analyses of the data sets generated with the two methods revealed that the AFLP-derived phylogenetic relationships were not in disagreement with the ITS-derived tree. The fungal phylogenetic tree correlated additionally with one from the graminaceous hosts generated
128 citations
TL;DR: The developmental sequence of perithecia from ho- mothallic Group II isolates of G. zeae was traced by light microscopy and typical croziers formed in the hymenium.
Abstract: Gibberella zeae (anamorph Fusarium graminearum) is the causal agent of head blight, and foot and crown rots of wheat, corn, oats and barley. The developmental sequence of perithecia from homothalli...
116 citations
TL;DR: Results indicate that the excess of moisture in continuously moist tropical forests does not favor myxomycete growth and de- velopment, and species richness and frequency patterns for both substrate types were found to be comparable with those calculated from a data set reported for a study area in the temperate zone.
Abstract: The moist chamber culture technique was used to examine patterns of biodiversity and distribution of myxomycetes in four different forest types in Costa Rica, focusing on the substrates represented...
110 citations
TL;DR: The results of the study show that species richness of EMF in Brazil is higher than previously demonstrated.
Abstract: The occurrence of ectomycorrhizal fungi (EMF) was assessed during 4 seasons (1 yr) in 10 plantations of Eucalyptus spp. and Pinus spp. in the state of Santa Catarina, southern Brazil. Forty-nine pr...
TL;DR: The results from this study may facilitate the future use of ancient fungi in studies of fungal ecol- ogy, distribution, epidemiology, phylogeny, and evo- lution.
Abstract: Glacial ice is a unique matrix that is ca- pable of protecting microorganisms for long-term preservation. The organisms entrapped in glacial ice can provide information on evolutionary processes and ancient biodiversity. The major objective of this study was to detect and characterize ancient fungi in glacial ice and determine their viability. We devel- oped a protocol using rigorous decontamination pro- cedures, conventional cultural methods, and molec- ular techniques (polymerase chain reaction amplifi- cation of fungal ribosomal DNA internal transcribed spacers, followed by sequence analyses) to examine the ancient fungi entrapped in glacial ice. Fifteen gla- cial ice subcores, ranging in age from several hun- dred to 140 000 yr, from two locations in Greenland were used in this study. One hundred ninety fungal isolates were obtained using conventional cultural methods. In this paper we report the morphological and molecular characteristics of eight isolates, includ- ing two Penicillium spp., three Cladosporium spp., one Ulocladium sp., one basidiomycete (Pleurotus sp.), and one unknown ascomycete. In addition, ten fun- gal sequences were amplified and sequenced directly from ice meltwater. One of them was identified as a basidiomycete. The other nine were classified as as- comycetes, of which three sequences had very low similarities with contemporary sequences in Gen- Bank. The results from this study may facilitate the future use of ancient fungi in studies of fungal ecol- ogy, distribution, epidemiology, phylogeny, and evo- lution.
TL;DR: Maximum parsimony analysis of ichthyosporean and fungal SSU sequences, using sequences of choanoflagellates to root the 18S rDNA gene trees, resolved A. parasiticum as a strongly sup- ported sister of I. hoferi within the Ichthyophonida clade of the protozoan class Ichthyosporea.
Abstract: Classification of the Amoebidiales (Tricho- mycetes, Zygomycota) within the Fungi is problem- atical because their cell walls apparently lack chitin and they produce amoeboid cells during their life cycle. A nearly full length fragment of the nuclear small subunit (SSU) rRNA of Amoebidium parasiticum was amplified by the polymerase chain reaction (PCR) and sequenced to examine its phylogenetic relationships. Results of a BlastN search of GenBank revealed that the A. parasiticum SSU rRNA sequence was most closely related to that of Ichthyophonus hof- eri, an ichthyosporean in the Protozoa near the ani- mal-fungal divergence. Maximum parsimony analysis of ichthyosporean and fungal SSU sequences, using sequences of choanoflagellates to root the 18S rDNA gene trees, resolved A. parasiticum as a strongly sup- ported sister of I. hoferi within the Ichthyophonida clade of the protozoan class Ichthyosporea. In con- trast to other members of this class, which are mostly obligate or facultative parasites of various animals, A. parasiticum and other members of the Amoebidiales are only known to be arthropodophilous symbionts. The results also provide the first evidence that mito- chondrial cristae types exhibit homoplastic distribu- tions within the Ichthyosporea.
TL;DR: The PleuroTaceae belong in the Agar- icales, are not closely related to or synonymous with the Polyporaceae, and should be restricted to the genera Pleurotus and Hohenbuehelia.
Abstract: Phylogenetic analyses based on partial se- quences from nuclear 25S rDNA indicate a mono- phyletic Pleurotaceae, consisting of the monophyletic genera Pleurotus and Hohenbuehelia, within the poly- phyletic pleurotoid-lentinoid fungi. The attack and consumption of nematodes (nematophagy) supports the monophyly of this family. Other pleurotoid-len- tinoid fungi that have been studied are not nemato- phagous and, in phylogenetic analyses, occur within the euagaric, polyporoid and russuloid clades. The pleurotoid agarics Lampteromyces, Lentinula, Notho- panus, and Omphalotus form a clade together with Gymnopus dryophilus. A clade that corresponds to the Tricholomataceae includes the pleurotoid agarics Conchomyces, Hypsizygus, Phyllotopsis, and Resupina- tus. Faerberia, Heliocybe, Lentinus, Neolentinus, and Panus are gilled polypores, and all deserve recogni- tion at the generic level. The brown-rotters Heliocybe and Neolentinus form a distinct clade within the poly- pores together with the brown-rotting polypore, Gloeophyllum. The Pleurotaceae belong in the Agar- icales, are not closely related to or synonymous with the Polyporaceae, and should be restricted to the genera Pleurotus and Hohenbuehelia. An isolate of Hohenbuehelia from Alberta, Canada produces adhe- sive knobs typical of Hohenbuehelia and its anamorph Nematoctonus, and also nonadhesive nematotoxic droplets characteristic of Pleurotus. This combination is unique within Hohenbuehelia and Pleurotus. Phylo-
TL;DR: High levels of ITS sequence variation were discovered, and sequences from different spores and different soil samples were sometimes more similar than sequences of the same spore or soil sample.
Abstract: Sequences of the nuclear rDNA ITS re- gion were sampled from a natural population of an arbuscular mycorrhizal fungus, Acaulospora colossica. Genetic diversity was explored through three levels of sampling: within an individual (a single spore), between individuals of a single soil sample, and be- tween individuals of different soil samples across a 36 m2 area. High levels of ITS sequence variation were discovered, and sequences from different spores and different soil samples were sometimes more similar than sequences of the same spore or soil sample. These results demonstrate a complex pattern of rDNA organization within a natural population of Glomalean fungi, and challenge ideas of individuality and collectivism in fungi.
TL;DR: The morphology-based classification of Chaetosphaeria is compared with results from analyses of molecular data and the taxonomic value of morphological characters observed in teleomorphs and dematiaceous hyphomycetous anamorphs is discussed in the light of the results of these analyses.
Abstract: In order to more fully elucidate the phylogenetic relationships of the lignicolous, pyrenomycetous genus Chaetosphaeria and its anamorphs and reveal the most reliable molecular data set we ...
TL;DR: The genera Lulwor- thia and Lindra are removed from Halosphaeriales and assigned to the new order Lulworthiales and new family LULworthiaceae in the class Sordariomycetes.
Abstract: Based on molecular studies using 1031 bp of the nuclear small subunit (SSU) gene and 594 bp of the nuclear large subunit (LSU) rDNA gene and using morphological characters, the genera Lulwor- thia and Lindra are removed from Halosphaeriales and assigned to the new order Lulworthiales and new family Lulworthiaceae in the class Sordariomycetes. Eleven accepted species of Lulworthia and 6 species of Lindra are listed.
TL;DR: Hypoxylon, with at least 130 currently accepted species and varieties, is one of the largest genera of the Xylariaceae as discussed by the authors, and taxonomic aspects that define and delimit the genus have varied among the authors.
Abstract: Hypoxylon, with at least 130 currently accepted species and varieties, is one of the largest genera of the Xylariaceae. Taxonomic aspects that define and delimit the genus have varied among...
TL;DR: The effects of growth temperature on soluble carbohydrate and lipid content of Humicola marvinii, Geomyces pannorum and Mortierella elongata isolated from the Antarctic were investigated and the relative importance of lipid and carbohydrate metabolism in adaptation to temperature stress in these fungi is discussed.
Abstract: The effects of growth temperature on soluble carbohydrate and lipid content of Humicola marvinii, Geomyces pannorum and Mortierella elongata isolated from the Antarctic (Signy Island; 60° 43′S, 45°38′W) were investigated. Each of these fungi responded differently to suboptimal growth temperatures. At low temperatures Humicola marvinii accumulated cryoprotective carbohydrates (trehalose intracellularly and glycerol extracellularly), whereas Geomyces pannorum responded by altering its lipid composition with increases in unsaturated lipid content and overall unsaturation index. In the case of Mortierella elongata, features that may influence its ability to grow at low temperatures included the absence of detectable ergosterol, the presence of stearidonic acid and increased amounts of intracellular trehalose when grown at lower temperatures. The relative importance of lipid and carbohydrate metabolism in adaptation to temperature stress in these fungi is discussed.
TL;DR: Two data sets of fungal small subunit (SSU) rDNA sequences, one from the Ribosomal Da- tabase Project (RDP) with 485 sequences, and the other from the rRNA WWW Server (RNA-S) with 785 sequences, have been analyzed to estimate group sup- port and to compare tree topologies resulting from independently aligned, large data set of largely the same sequences.
Abstract: Two data sets of fungal small subunit (SSU) rDNA sequences, one from the Ribosomal Da- tabase Project (RDP) with 485 sequences, and the other from the rRNA WWW Server (RNA-S) with 785 sequences, have been analyzed to estimate group sup- port and to compare tree topologies resulting from independently aligned, large data sets of largely the same sequences. The analyses were conducted by us- ing a parsimony jackknifing computer program to search rapidly for supported groups in combination with branch swapping and random addition sequenc- es. The results show that gross topology is very simi- lar. The major differences were with the Ascomycetes, which were not recovered in the RDP tree, and with the Holobasidiomycetes, which were not recovered in the RNA-S tree. Both data sets identify and support many well known fungal groups such as the Gloma- les, Saccharomycetes, Dikaryomycetes, Basidiomy- cetes, Uredinomycetes, Ustilaginomycetes, Euasco- mycetes, Leotiomyceta, Sordariomycetes and the Chaetothyriomycetes. No support was found for some previously proposed groups, including the Chy- tridiomycetes, Taphrinomycotina, Pezizomycotina through Pezizales, Hymenomycetes, Tremellomyce- tes, Leotiomycetes and the Dothideomycetes. The analysis contradicted some other previously proposed groups, among them the Zygomycota, Zygomycetes, Lecanoromycetes and the Sordariomycetidae. Trans- version parsimony performed on the same data sets
TL;DR: A preliminary key to and descriptions of these species are provided in an attempt to help to sort out the confused taxonomic situation which has prevailed in the genus Ganoderma.
Abstract: The Ganoderma lucidum complex in tropical America has been studied based on an examination of available types for all laccate Ganoderma species described from tropical America and 13 species are cu...
TL;DR: In this study, four genetically distinct isolates of C. immitis were isolated from soil samples from the San Joaquin Valley without the use of a host.
Abstract: The fungal pathogen Coccidioides immitis, causative agent of coccidioidomycosis or Valley Fever, was first isolated from the environment in 1932. It has been isolated on numerous occasions since th...
TL;DR: An intensive sampling in French vineyards affected by the Esca disease has shown that this species is rare compared to P. aleophilum and P chlamydosporum and is often associated with symptoms on the fruits.
Abstract: A group of Phaeoacremonium isolates first distinguished by the red pigmentation of the reverse of their colonies, is described as a new species, P. viticola, on the basis of molecular data. An intensive sampling in French vineyards affected by the Esca disease has shown that this species is rare compared to P. aleophilum and P chlamydosporum and is often associated with symptoms on the fruits.
TL;DR: The data suggest that A. mellea populations from different regions are genet- ically isolated and may be in the process of speciation, and there are four separate groups of A.Mellea distinguished by their geograph- ical origin: Asia, western North America, eastern North America and Europe.
Abstract: Armillaria mellea was once thought to be a morphologically variable species with a wide distri- bution and a very broad host range. The relatively recent development of an indirect assessment of sex- ual incompatibility in Armillaria has led to identifi- cation of biological species within A. mellea s. 1. Par- tial intergenic spacer region (IGS) sequences of the ribosomal RNA (rRNA) operon have been deter- mined for most of the Northern Hemisphere species of Armillaria, but not for A. mellea s. s. The aim of this study was to determine the phylogenetic rela- tionships among isolates of A. mellea s. s. based on DNA sequences from the IGS as well as the internal transcribed spacer (ITS) regions. The IGS and the ITS sequence data indicate that A. mellea is highly variable but phylogenetically distant from the other species of Armillaria, and there are four separate groups of A. mellea distinguished by their geograph- ical origin: Asia, western North America, eastern North America and Europe. The data suggest that A. mellea populations from different regions are genet- ically isolated and may be in the process of specia- tion.
TL;DR: An outline of what may be regarded as two separate genera of Cortinarius is presented, one centered around the members of the subgenus Telamonia, the other comprising the majority of ingroup taxa in- cluding Rozites.
Abstract: Internal transcribed spacer (ITS) nuclear ribosomal DNA (rDNA) sequences of 27 species of Cortinarius representing the subgenera Cortinarius, Dermocybe, Leprocybe, Myxacium, Phlegmacium, Sericeocyb...
TL;DR: In this paper, phylogenetic relationships within the ge- nus Hebeloma (Cortinariaceae, Agaricales) were de-termined, based on nuclear ribosomal ITS sequenc- es, using cladistic methods.
Abstract: Phylogenetic relationships within the ge- nus Hebeloma (Cortinariaceae, Agaricales) were de- termined, based on nuclear ribosomal ITS sequenc- es, using cladistic methods. Special emphasis was on phylogenetic relationships within the H. crustulini- forme complex. In total 52 sequences were analysed, representing 51 collections and 39 taxa. Agrocybe praecox and two species of Alnicola were used as out- groups. The genus Hebeloma appears to be mono- phyletic. Several well supported clades could be rec- ognized. However, many of the basal relationships are unresolved or only weakly supported. Alternative to- pologies could not be rejected. It is therefore impos- sible to derive a revised infrageneric classification of Hebeloma. The H. crustuliniforme complex appears paraphyletic, consisting of two clades with three and 17 intercompatibility groups respectively. In the sec- ond clade many of the phylogenetic relationships are also unresolved, reflecting a high rate of recent spe- ciation events. Most of the species in this clade form ectomycorrhizae with members of the Salicaceae. The taxon that is basal to this clade, however, is not associated with these hosts. The host tree switch to
TL;DR: Three species of pleurotoid, putatively lig- nicolous basidiomycetes previously described in the genus Lactarius sect Panuoidei were redescribed from fresh material collected in Guyana and Japan, confirming that these fungi are ectomycorrhizal and that their fruiting habit on organic deposits and well rotted wood at elevated positions is not due to sap- rotrophy, as previously assumed.
Abstract: Three species of pleurotoid, putatively lig- nicolous basidiomycetes previously described in the genus Lactarius sect Panuoidei were redescribed from fresh material collected in Guyana andJapan. In Guy- ana, Lactarius panuoides and Lactarius campinensis were restricted to forests dominated by ectomycor- rhizal Dicymbe species (Caesalpiniaceae) and basi- diomata of both pleurotoid species were subtended by ectomycorrhizal rootlets. This suggested an ecto- mycorrhizal nutritional mode for these fungi. Analy- sis of DNA sequences in the nuclear large subunit region taken from basidiomata and co-occurring ec- tomycorrhizae of L. panuoides and L. campinensis confirmed that these fungi are ectomycorrhizal and that their fruiting habit on organic deposits and well rotted wood at elevated positions is not due to sap- rotrophy, as previously assumed. Lactarius uyedae was collected in Japan from mature temperate forests dominated by Fagaceae, yet ectomycorrhizal rootlets were not found in association with the basidiomata. Morphological features and analysis of DNA sequenc- es suggested that L. panuoides and L. uyedae have affinities with established sections of the genus Lac- tarius, regardless of the pleurotoid morphology of their basidiomata, and that L. campinensis should be transferred to the genus Russula. Discussion is pro- vided for the genus Pleurogala, which was erected to accomodate putatively lignicolous, pleurotoid species
TL;DR: A grape leaf rust fungus, Phakopsora ampelopsidis, distributed in Japan consisted of three populations differing in their life cycle and host specificity, one population forms the uredinial population.
Abstract: A grape leaf rust fungus, Phakopsora ampelopsidis, distributed in Japan consisted of three populations differing in their life cycle and host specificity. One population forms the uredinial...
TL;DR: The first molecular analysis of arbuscular mycorrhizal fungi previously classified in the genus Sclerocystis indicates that formation of complex spo- rocarps is an advanced character of some Glomus spe- cies, but the sporocarpic trait is not sufficiently unique to group these species into a separate genus.
Abstract: We report the first molecular analysis of arbuscular mycorrhizal fungi previously classified in the genus Sclerocystis. Fungi in Sclerocystis sensu lato were distinguished by formation of complex sporo- carps. Most species were transferred to Glomus, but both their taxonomic and phylogenetic relations re- main the subject of controversy. Phylogenetic analysis of the 18S ribosomal subunit of G. sinuosum (= S. sinuosa) and S. coremioides shows that both species are each other's closest relatives and fall within a mono- phyletic clade comprising the well-characterized spe- cies, G. mosseae, G. intraradices and G. vesiculiferum, to the exclusion of several other Glomus species. This placement indicates that formation of complex spo- rocarps is an advanced character of some Glomus spe- cies, but the sporocarpic trait is not sufficiently unique to group these species into a separate genus
TL;DR: A new arbuscular mycorrhizal fungus, Glomus proliferum (Glomales, Zygomycetes) is described, which combines sequencing of the small subunit (SSU) rDNA, spore sterols and fatty acid profiles with more classical taxonomic tools such as optical and electron microscopy.
Abstract: A new arbuscular mycorrhizal fungus, Glomus proliferum (Glomales, Zygomycetes) is described. The description, based on a monoxenic culture established in association with a Ri T-DNA transformed carrot root, combines sequencing of the small subunit (SSU) rDNA, spore sterols and fatty acid profiles with more classical taxonomic tools such as optical and electron microscopy. The fungus forms clusters containing hundreds of small, hyaline, four-layered spores. The necessity to use different tools for identification of arbuscular mycorrhizal fungi is discussed.