Showing papers in "Mycologia in 1998"
TL;DR: Phylogenetic relationships of the phyto-pathogenic Gibberella fujikuroi species complex were investigated by maximum parsimony analysis of DNA sequences from multiple loci.
Abstract: Phylogenetic relationships of the phyto-pathogenic Gibberella fujikuroi species complex were investigated by maximum parsimony analysis of DNA sequences from multiple loci. Gene trees inferred from...
947 citations
TL;DR: Ten Fusarium species within the Gibberella fujikuroi complex are described and illustrated as new species.
Abstract: Ten Fusarium species within the Gibberella fujikuroi complex are described and illustrated as new species: F. acutatum ex Triticum sp. (wheat) and Cajanus sp.,F. begoniae ex Begonia elatior hybrid,...
510 citations
TL;DR: A new fungus isolate was discovered in an arbuscular mycorrhizal fungal spore from a desert soil in India that could easily be cultivated on various synthetic media, and formed pear-shaped chlamydos...
Abstract: A new fungus isolate was discovered in an arbuscular mycorrhizal fungal spore from a desert soil in India. It could easily be cultivated on various synthetic media, and formed pear-shaped chlamydos...
448 citations
TL;DR: Five arbuscular mycorrhizal fungi, isolated from the rhizosphere of banana and sugar cane, were successfully cultured in vitro in association with genetically transformed roots of carrot, and appeared suitable for the establishment of in vitro collections of AM fungal strains.
Abstract: Five arbuscular mycorrhizal (AM) fungi, isolated from the rhizosphere of banana and sugar cane, were successfully cultured in vitro in association with genetically transformed roots of carrot. The intraradical forms of the fungi as mycorrhizal root pieces and single isolated vesicles constituted excellent sources of inoculum for the establishment of in vitro cultures and for the continuous culture of the species. Several thousand fungal propagules were obtained for the two G. versiforme species, G. intraradices and to a lesser extent for G. fasciculatum whereas few spores were obtained for G. macrocarpum. This coculture system appeared suitable for the establishment of in vitro collections of AM fungal strains.
206 citations
TL;DR: Soil populations of Aspergillus species from section Flavi, several of which produce aflatoxins and cyclopiazonic acid, were examined from 166 cultivated fields along a transect extending from east to west.
Abstract: Soil populations of Aspergillus species from section Flavi, several of which produce aflatoxins and cyclopiazonic acid, were examined from 166 cultivated fields along a transect extending from east...
171 citations
TL;DR: Anamorphs of 22 strains of botryosphaer- iaceous fungi including Fusicoccum, Diplodia, Sphaeropsis, and Lasiodiplodia theobromae wereared utilizing conidial characters, cultural morphol- ogy, growth rates and nucleotide sequences of the nuclear rDNA internal transcribed spacers ITS 1 and ITS 2.
Abstract: Anamorphs of 22 strains of botryosphaer- iaceous fungi including Fusicoccum spp., Diplodia spp., Sphaeropsis spp., and Lasiodiplodia theobromae (teleomorph = Botryosphaeria rhodina) were com- pared utilizing conidial characters, cultural morphol- ogy, growth rates and nucleotide sequences of the nuclear rDNA internal transcribed spacers ITS 1 and ITS 2. The ITS data shared consensus with morpho- logical and cultural characters in separating 7 of the 22 strains. The 7 strains were placed into one of three groups that corresponded with the morphological species L. theobromae, S. sapinea, and F. luteum. Only partial consensus was achieved with the remaining 15 strains as ITS sometimes grouped together strains with uniform morphological and cultural characters and other times not. The ten Fusicoccum strains, iden- tified as anamorphs of B. dothidea or B. ribis, were divided into two ITS groups and up to five groups based on traditional characters. The two putative B. ribis strains were consistently grouped together and appear to represent a stable variant of B. dothidea.
163 citations
TL;DR: Mixed interrelationships were found among strictly mitotic, homothallic and heterothallic taxa, suggesting multiple independent losses of the Neosartorya sexual state and possible derivation of heterothallism from homothallists through loss of self compatibility.
Abstract: Members of Aspergillus section Fumigati are important animal pathogens and food contami- nants There is considerable variation among the 16 currently recognized species in this section, particu- larly in their mating systems: five are known to be strictly mitosporic, nine are homothallic, and two are heterothallic Phylogenetic relationships were in- ferred among members of Aspergillus section Fumi- gati based on partial DNA sequences from the benA (-tubulin and rodA hydrophobin genes Aspergillus clavatus was chosen as an outgroup The two gene regions provided nearly equal numbers of phyloge- netically informative nucleotide characters The rodA region possessed a considerably higher level of in- ferred amino acid variation than did the benA region The results of a partition homogeneity test showed that the benA and rodA data sets were not in signifi- cant conflict, and the topologies of the most parsi- monious trees for the two data sets differed only in branches that were not strongly supported by boot- strapping The data sets in combination showed that morphological and secondary metabolite characters used in taxonomy were not strongly correlated with phylogeny Mixed interrelationships were found among strictly mitotic, homothallic (selfing and out- crossing) and heterothallic (obligately outcrossing) taxa, suggesting multiple independent losses of the Neosartorya sexual state and possible derivation of heterothallism from homothallism through loss of self compatibility The food spoiling species N fischeri
148 citations
TL;DR: The intricate architecture shown by the ex- traradical mycelium highlights the potential for nutrient uptake by mycorrhizal roots, and their role in the maintainance and amelioration of soil structure.
Abstract: The structural development of arbuscular mycorrhiza extraradical mycelium is difficult to fol- low in soil-based systems. The use of dual arbuscular mycorrhizal fungi/in vitro root organ cultures (mon- oxenic AM cultures) allowed the nondestructive study of hyphal development following establishment of the symbiosis. The present study shows that the extraradical spreading of the arbuscular mycorrhizal fungus Glomus intraradices grown monoxenically with tomato roots can be divided into three stages: (i) pro- liferation of runner hyphae acting as conducting channels, which divide dichotomously and extend the fungal colony radially; (ii) development of arbus- cule-like structures, which are formed at regular in- tervals along the runner hyphae and which might play a preferential role in nutrient uptake; and (iii) formation of spores in zones already colonized by runner hyphae and arbuscule-like structures. The de- velopment of the mycorrhiza is accompanied by changes in the pH of the medium. In particular, pH decreases in zones of the medium in which a high number of arbuscular mycorrhizal fungal spores are formed. The intricate architecture shown by the ex- traradical mycelium highlights the potential for en- hanced nutrient uptake by mycorrhizal roots, and their role in the maintainance and amelioration of soil structure.
133 citations
TL;DR: It is suggested that the fungal endophyte communities of pe- rennial grasses may be as diverse as fungalendophytes communities of woody shrubs and trees, despite high infection levels of the asexual and vertically-transmit- ted Neotyphodium.
Abstract: We documented patterns of species diversity, relative abundances, and associations of the fungal endophyte community inhabiting Arizona fescue (Festuca arizonica), a dominant perennial bunchgrass i...
131 citations
TL;DR: This study extracted fungal DNA from spores of Cronartium and its anamorphic genus Peridermium, causing severe economic and aesthetic damage to pines in forests and parks throughout the northern hemisphere.
Abstract: Species in Cronartium and its anamorphic genus Peridermium form a morphologically homoge- neous group of rust fungi that infect stems, branches, and cones of Pinus species in North and Central America, Asia, and Europe. Several species are im- portant forest pathogens, causing severe economic and aesthetic damage to pines in forests and parks throughout the northern hemisphere. Morphologi- cal characters have been used to distinguish among these rust fungi, but have proven inadequate for as- sessing phylogenetic relationships within the group. In this study, we extracted fungal DNA from spores
TL;DR: Random amplified polymorphic DNA- PCR (RAPD-PCR) analysis was used to investigate genetic variation among isolates of Alternaria solani, the causal agent of early blight on solanaceous crops, and A. alternata, an opportunistic pathogen, suggesting the possibility of pathogenic specialization.
Abstract: Random amplified polymorphic DNA-PCR (RAPD-PCR) analysis was used to investigate genetic variation among 35 isolates of Alternaria solani, the causal agent of early blight on solanaceous crops, and...
TL;DR: Phytophthora diseases worldwide, Phytophile diseases worldwide , مرکز فناوری ا�لاعات و اطllاع رسانی, کδاوρزی
Abstract: Phytophthora diseases worldwide , Phytophthora diseases worldwide , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
TL;DR: DNA sequences of the nuclear encoded small subunit (SSU) 18S ribosomal RNA gene and characters from a morphological/physiological dataset were analyzed by maximum parsimony to investigate phylogeneicity.
Abstract: DNA sequences of the nuclear encoded small subunit (SSU) 18S ribosomal RNA gene and characters from a morphological/physiological dataset were analyzed by maximum parsimony to investigate phylogene...
TL;DR: Parsimony analyses of 23 Oidiodendron strains showed that three highly supported monophyletic groups are resolved within the genus and a low level of sequence divergence between the species in these pairs suggests conspe- cificity for each pair.
Abstract: Nuclear ribosomal DNA sequences (ITS region) of fifteen species in the hyphomycete genus Oidiodendron and ten species from the 4 genera in the Myxotrichaceae, Byssoascus, Gymnostellatospora, Myxotrichum, and Pseudogymnoascus, were analysed to: (i) reveal the levels of intra- versus interspecific sequence variation within the genus Oidiodendron, clarify species delimitation and examine the useful- ness of some morphological characters used for iden- tification; (ii) assess the possible conspecificity of doc- umented ericoid mycorrhizal strains of Oidiodendron; and (iii) test the hypothesis based on morphological inference that the genus Oidiodendron belongs with the genus Myxotrichum in the Myxotrichaceae (Ony- genales). Comparison of molecular and morpholog- ical data for multiple strains of 0. griseum, 0. tenuis- simum and 0. maius revealed that conidiophore length and the production of a diffusing pigment are not reliable key characters for the genus. Several his- torically important ericoid mycorrhizal strains, doc- umented as 0. griseum, were reidentified as 0. maius. Parsimony analyses of 23 Oidiodendron strains showed that three highly supported monophyletic groups, each one consisting of a pair of species, are resolved within the genus. A low level of sequence divergence between the species in these pairs suggests conspe- cificity for each pair. Other interspecific relationships were not well-supported by bootstrap values. Parsi- mony analysis of a second dataset composed of mi- totic and meiotic taxa showed that Oidiodendron, My- xotrichum and Byssoascus form a well-supported monophyletic group within the Myxotrichaceae, and
TL;DR: The central goal of taxonomic mycology is to create classifications that communicate under- standing of fungal phylogeny, and there must be efficient mechanisms for translating phylogenetic trees into classifications.
Abstract: The central goal of taxonomic mycology is to create classifications that communicate under- standing of fungal phylogeny. To insure that taxon- omy reflects up-to-date phylogenetic hypotheses, there must be efficient mechanisms for translating phylogenetic trees into classifications. The current taxonomic system, which is based on the hierarchy of Linnaean ranks and the International Code of Bo-
TL;DR: Trichoderma harzianum is neotypified by an isolate from the type locality, and this neotype is fully described.
Abstract: Trichoderma harzianum is neotypified by an isolate from the type locality, and this neotype is fully described. It is compared with original herbarium specimens and recent isolates of T. at...
TL;DR: Nucleotide sequences of internal transcribed spacers (ITS-1 and ITS-2) and the 5.8 S gene of the ribosomal DNA repeat were examined in 15 lines of Trichoderma spp.
Abstract: Nucleotide sequences of internal transcribed spacers (ITS-1 and ITS-2) and the 5.8 S gene of the ribosomal DNA repeat were examined in 15 lines of Trichoderma spp. Six lines representing four bioty...
TL;DR: Par- simony analysis indicates that both Agaricus and Co- prinus section Comati are nested within the lepiotoid fungi, which is consistent with the exclusion of the tribe Cystoderma and Ripartitella from the family Agaricaceae, and the retention of the tribes Lepi- oteae and Leucocoprineae.
Abstract: Taxonomic circumscription and segrega- tion of the genus Lepiota has been problematic. Phy- logenetic relationships were investigated for lepi- otoid and closely related taxa using DNA sequence data. Our analysis reflects a broad sampling across eight segregate genera used by Singer: Lepiota s.s., Cystolepiota, Leucocoprinus, Leucoagaricus, Macrolepi- ota, Chlorophyllum, Cystoderma, and Ripartitella (Agaricaceae, Agaricales, Basidiomycota). Related fungi were evaluated from the dark-spored genera Agaricus and Coprinus and representative secotioid and attine fungi, along with more distantly related fungi. DNA sequences were compared for the 5' end region of the nuclear encoded large subunit riboso- mal RNA gene (25-28S rDNA) from 55 ingroup and outgroup taxa. Results from parsimony analysis are consistent with the exclusion of the tribe Cystoder- mateae (Cystoderma and Ripartitella) from the family Agaricaceae, and the retention of the tribes Lepi- oteae and Leucocoprineae. Lepiotoid segregate gen- era remain poorly resolved using this molecule. Par- simony analysis indicates that both Agaricus and Co- prinus section Comati are nested within the lepiotoid fungi. The support for Coprinus section Comati to be within the Agaricaceae presents interesting taxonom- ic problems involving nomeclatural precedence and usage of commonly known groups including Agari- cus, Coprinus, and Lepiota.
TL;DR: Phylogenetic analyses of these sequences supported previous re- ports that the Herpotrichiellaceae (Capronia, black yeasts, etc.) are distant from Dothideales and Pleo- sporales, and a new sequence of Ceramothyrium linnaeae is mono- phyletic with representatives of the Herpotsrichiella- ceae, suggesting that both families can be accom- modated in the order Chaetothyriales.
Abstract: The 18S rRNA gene sequences from the bitunicate ascomycetes Ceramothyrium linnaeae (Chaetothyriaceae) and Coccodinium bartschii (Coc- codiniaceae) were determined and aligned with the corresponding sequences from 33 other ascomycetes and one basidiomycete, Boletus satanas. Phylogenetic analyses of these sequences supported previous re- ports that the Herpotrichiellaceae (Capronia, black yeasts, etc.) are distant from Dothideales and Pleo- sporales. A new sequence of Ceramothyrium linnaeae, representing the family Chaetothyriaceae, is mono- phyletic with representatives of the Herpotrichiella- ceae, suggesting that both families can be accom- modated in the order Chaetothyriales. The concept of Chaetothyriales can not be based on the presence of periphysoids, since Coccodinium bartschii, which also has periphysoids, clustered with members of the Dothideaceae. The Chaetothyriales are not closely re- lated to other bitunicates, but are the sister group of either Eurotiales or Lecanorales/Peltigerales.
TL;DR: A powdery mildew (Erysiphales) infection of Arabidopsis thaliana was found in the greenhouse of the Department of Molecular Biology at Massachu- setts General Hospital (MGH isolate) and was found to be a member of the E. cichoracearum group in the section Golovinomyces.
Abstract: A powdery mildew (Erysiphales) infection of Arabidopsis thaliana was found in the greenhouse of the Department of Molecular Biology at Massachu- setts General Hospital (MGH isolate). We studied the structure of the anamorph, the sequence and chro- nology of its development, and its virulence on A. thaliana and other hosts. The teleomorph of the fun- gus was not found on the material we examined. The MGH isolate caused severe powdery mildew symp- toms on some A. thaliana accessions, infecting ro- sette and cauline leaves, stems and siliques, but was practically avirulent on others. Previously, two Erysi- phales have been reported to infect A. thaliana. These were identified as Erysiphe cichoracearum (UCSC isolate) and E. cruciferarum (UEA isolate). The MGH isolate was found to be a member of the E. cichoracearum group in the section Golovinomyces. It can be distinguished from both of these previously described powdery mildews of A. thaliana based on the morphology, host range and virulence. It might be best referred to E. orontii following the system pro- posed by Braun.
TL;DR: Intensive sampling of British Columbia isolates of Armillaria species confirmed the useful- ness of a species diagnostic based on restriction site differences in the first ribosomal intergenic spacer region, and provides additional data for species which have the same restriction sites in the second intergenicSpacer.
Abstract: Intensive sampling of British Columbia isolates of Armillaria species confirmed the useful- ness of a species diagnostic based on restriction site differences in the first ribosomal intergenic spacer region. Greater variation within species and new frag- ment patterns were observed compared to earlier re- ports. The only species confusion observed using this marker was between A. gallica and some isolates of A. sinapina. These isolates could be distinguished by restriction site differences in the second intergenic spacer. Use of both sections of the ribosomal inter- genic spacer region confirms identifications based on the first intergenic spacer, and provides additional data for species which have the same restriction sites in the first intergenic spacer.
TL;DR: It is suggested that molec- ular data such as SSU rDNA sequences be used in the description of Glomales species, and PCR-finger- printing could be used to study diversity within spe- cies ofglomales.
Abstract: Isolates of Glomus mosseae from interna- tional collections were compared using two molecu- lar techniques: PCR-fingerprinting of genomic DNA with direct amplification of microsatellite regions, and sequencing of the small subunit (SSU) rDNA. Numerical analyses of these data using parsimony models were used to calculate phylogenetic topolo- gies. The phylogenetic tree from SSU rDNA sequenc- es was similar to the phylogenetic trees obtained from genomic fingerprinting using the amplification of microsatellite regions, except for one G. mosseae isolate, DAOM221475. Another isolate was not grouped with the other G. mosseae isolates by either method and was found to be Glomus sp. a posteriori. Both analyses showed considerable genetic variation within the species G. mosseae. We suggest that molec- ular data such as SSU rDNA sequences be used in the description of Glomales species, and PCR-finger- printing could be used to study diversity within spe- cies of Glomales.
TL;DR: DNA sequencing and phylogenetic analysis indicate that there are cryptic species in the Puccinia monoica complex, and that species in this group cannot be identified strictly by life cycle stage.
Abstract: The Puccinia monoica complex is an enig- matic group of rust fungi They are flower mimics, and they greatly reduce host reproduction and sur- vival These fungi are relatively common, attacking approximately 960 species in 11 genera of crucifers as well as at least five genera of grasses In modern taxonomic treatments the Puccinia monoica complex is treated as four species that are differentiated by the number of spore states in their life cycles How- ever, other systematic treatments have divided the group into species or forms based on host associa- tion Within the species based on spore state there is morphological variation, but it has not been readily assignable to either host species or geographic area We used DNA sequencing and phylogenetic analysis to determine whether there are cryptic species in this group that are not evident when only morphology is used We sequenced the nuclear rDNA region con- taining the internal transcribed spacers (ITS-1 + 58S gene + ITS-2) of isolates from different hosts Our results indicate that there are cryptic species in the Puccinia monoica complex, and that species in this group cannot be identified strictly by life cycle stage
TL;DR: Through an extraordinary series of experiments the composition of the drop has been established, its development is explained, and an effective solu- tion to the relationship between drop appearance and spore discharge has been proposed.
Abstract: Ballistospores of basidiomycete fungi form at the tips of spear-shaped projections called sterig- mata that extend from basidia. At maturity, a spher- ical drop of fluid appears at the base of each spore, and a few seconds later the spore is propelled into the surrounding air. The development of the fluid drop was first reported in 1889, but a century of in- novative research was necessary to solve the mecha- nistic link between the drop and spore discharge. Through an extraordinary series of experiments the composition of the drop has now been established, its development is explained, and an effective solu- tion to the relationship between drop appearance and spore discharge has been proposed. Drop for- mation is initiated when a femtomole quantity of mannitol and hexoses is excreted from a specific site at the base of the spore, forming a hygroscopic nu- cleus upon which water condenses from the sur- rounding air. Discharge of the spore occurs when the drop fuses with a film of liquid that curves over the adjacent spore surface. This rapid coalescence results in a decrease in surface free energy within the liquid and displaces the center of mass of the spore. The change in weight distribution exerts a force that is opposed by the pressurized sterigma, and the spore is shot away from the basidium into the surrounding air. The mechanism is described as a surface-tension catapult. During discharge, ballistospores are subject- ed to an acceleration of 25 000 g, which is about ten thousand times the acceleration experienced by as- tronauts during the launch of the Space Shuttle! Even more impressive is the fact that while the Shut- tle consumes 50% of its weight in fuel in the first 2 min of flight, ballistospore discharge is fueled by the mannitol and hexoses that cause water to condense on the spore surface, and these solutes represent only 1% of the mass of the spore.
TL;DR: DNA polymorphisms were used to infer relationships of a morphologically distinct new strain of aflatoxin-producing AsperGillus to other members of Aspergillus sect.
Abstract: DNA polymorphisms were used to infer relationships of a morphologically distinct new strain of aflatoxin-producing Aspergillus to other members of Aspergillus sect. Flavi. The new strain produced b...
TL;DR: Compared isolates of C. coerulescens sensu lato and morphologically similar species, the five morphological types previously known as C. fimbriata formed a strongly-supported monophyletic group that includes all the Ceratocystis species occurring primarily on conifers.
Abstract: Ceratocystis sensu stricto includes numer- ous species of insect-vectored, wood-staining and plant pathogenic fungi. Among these, Ceratocystis coe- rulescens is a well-known cause of blue-stain in spruce and pine. Previous investigations, using morphologi- cal characteristics and isozyme comparisons, have shown that C. coerulescens encompasses at least five morphological types. The aim of this study was thus to compare isolates of C. coerulescens sensu lato and morphologically similar species, including C. larici- cola, C. polonica, C. virescens, C. eucalypti, Chalara australis and Ch. neocaledoniae, on the basis of DNA sequence data. Using the polymerase chain reaction (PCR), a 600 base pair fragment within the ribosomal DNA operon was amplified, and the PCR products were sequenced. The analyzed sequence included the 5.8S rRNA gene and the internal transcribed spacers (ITS) 1 and 2. Relationships were deter- mined by parsimony analysis. Using C. fimbriata as the outgroup taxon, the five morphological types previously known as C. coerulescens and the two other taxa from conifers formed a strongly-supported monophyletic group that includes all the Ceratocystis species occurring primarily on conifers. The species from hardwood trees, C. eucalypti, Ch. australis and Ch. neocaledoniae, also formed a monophyletic group, sister to the conifer group. The fourth species from hardwoods, C. virescens, formed a group basal to the two sister groups.