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Elizabeth Cigelnik

Bio: Elizabeth Cigelnik is a academic researcher at National Center for Agricultural Utilization Research who has co-authored 8 publication(s) receiving 4977 citation(s). The author has an hindex of 8. The author has done significant research in the topic(s): Phylogenetic tree & Phylogenetics.

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Journal ArticleDOI: 10.1006/MPEV.1996.0376
Kerry O'Donnell1, Elizabeth Cigelnik1Institutions (1)
Abstract: The evolutionary history of the phytopathogenic Gibberella fujikuroi complex of Fusarium and related species was investigated by cladistic analysis of DNA sequences obtained from multiple unlinked loci. Gene phylogenies inferred from the mitochondrial small subunit (mtSSU) rDNA, nuclear 28S rDNA, and beta-tubulin gene were generally concordant, providing strong support for a fully resolved phylogeny of all biological and most morphological species. Discordance of the nuclear rDNA internal transcribed spacer 2 (ITS2) gene tree is due to paralogous or xenologous ITS2 sequences. PCR and sequence analysis demonstrated that every strain of the ingroup species tested possesses two highly divergent nonorthologous ITS2 types designated type I and type II. Only the major ITS2 type, however, is discernable when PCR products are amplified and sequenced directly with conserved primers. The minor ITS2 type was recovered using ITS2 type-specific PCR primers. Distribution of the major ITS2 type within the species lineages exhibits a homoplastic pattern of evolution, thus obscuring true phylogenetic relationships. The results suggest that the ancestral ITS2 types may have arisen following an ancient interspecific hybridization or gene duplication which occurred prior to the evolutionary radiation of the Gibberella fujikuroi complex and related species of Fusarium. The results also indicate that current morphological-based taxonomic schemes for these fungi are unnatural and a new classification is required.

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Topics: Lineage (evolution) (57%), Phylogenetic tree (55%), Phylogenetics (53%) ...read more

1,461 Citations


Open accessJournal ArticleDOI: 10.1073/PNAS.95.5.2044
Abstract: Panama disease of banana, caused by the fungus Fusarium oxysporum f. sp. cubense, is a serious constraint both to the commercial production of banana and cultivation for subsistence agriculture. Previous work has indicated that F. oxysporum f. sp. cubense consists of several clonal lineages that may be genetically distant. In this study we tested whether lineages of the Panama disease pathogen have a monophyletic origin by comparing DNA sequences of nuclear and mitochondrial genes. DNA sequences were obtained for translation elongation factor 1α and the mitochondrial small subunit ribosomal RNA genes for F. oxysporum strains from banana, pathogenic strains from other hosts and putatively nonpathogenic isolates of F. oxysporum. Cladograms for the two genes were highly concordant and a partition-homogeneity test indicated the two datasets could be combined. The tree inferred from the combined dataset resolved five lineages corresponding to “F. oxysporum f. sp. cubense” with a large dichotomy between two taxa represented by strains most commonly isolated from bananas with Panama disease. The results also demonstrate that the latter two taxa have significantly different chromosome numbers. F. oxysporum isolates collected as nonpathogenic or pathogenic to other hosts that have very similar or identical elongation factor 1α and mitochondrial small subunit genotypes as banana pathogens were shown to cause little or no disease on banana. Taken together, these results indicate Panama disease of banana is caused by fungi with independent evolutionary origins.

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Topics: Fusarium oxysporum f.sp. cubense (66%), Panama disease (64%), Fusarium oxysporum (61%) ...read more

1,336 Citations


Journal ArticleDOI: 10.1080/00275514.1998.12026933
01 Jun 1998-Mycologia
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...

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Topics: Gibberella fujikuroi (69%), Phylogenetic tree (53%), Maximum parsimony (53%) ...read more

886 Citations


Journal ArticleDOI: 10.1007/BF02464387
01 Jan 2000-Mycoscience
Abstract: Phylogenetic relationships within theGibberella fujikuroi species complex were extended to newly discovered strains using nucleotide characters obtained by sequencing polymerase chain reaction (PCR) amplified DNA from 4 loci used in a previous study [nuclear large subunit 28S rDNA, nuclear ribosomal internal transcribed spacer (ITS) region, mitochondriaal small subunit (mtSSU) ribosomal DNA, and β-tubulin] together with two newly sampled protein-encoding nuclear genes, translation elongation factor EF-1α and calmodulin. Sequences from the ribosomal ITS region were analyzed separately and found to contain of two highly divergent, nonorthologous ITS2 types. Phylogenetic analysis of the individual and combined datasets identified 10 new phylogenetically distinct species distributed among the following three areas: 2 within Asia and 4 within both Africa and South America. Hypotheses of the monophyly ofFusarium subglutinans and its two formae speciales, f. sp.pini and f. sp.ananas, were strongly rejected by a likelihood analysis. Maximum parsimony results further indicate that the protein-encoding nuclear genes provide considerably more phylogenetic signal that the ribosomal genes sequenced. Relative apparent synapomorphy analysis was used to detect long-branch attraction taxa and to obtain a statistical measure of phylogenetic signal in the individual and combined datasets.

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Topics: Ribosomal DNA (59%), Internal transcribed spacer (56%), Phylogenetic tree (56%) ...read more

418 Citations


Open accessJournal ArticleDOI: 10.1094/PHYTO.2000.90.8.891
01 Aug 2000-Phytopathology
Abstract: The monophyletic origin of host-specific taxa in the plant-pathogenic Fusarium oxysporum complex was tested by constructing nuclear and mitochondrial gene genealogies and amplified fragment length polymorphism (AFLP)-based phylogenies for 89 strains representing the known genetic and pathogenic diversity in 8 formae speciales associated with wilt diseases and root and bulb rot. We included strains from clonal lineages of F. oxysporum f. spp. asparagi, dianthi, gladioli, lilii, lini, opuntiarum, spinaciae, and tulipae. Putatively nonpathogenic strains from carnation and lily were included and a reference strain from each of the three main clades identified previously in the F. oxysporum complex; sequences from related species were used as outgroups. DNA sequences from the nuclear translation elongation factor 1alpha and the mitochondrial small subunit (mtSSU) ribosomal RNA genes were combined for phylogenetic analysis. Strains in vegetative compatibility groups (VCGs) shared identical sequences and AFLP profiles, supporting the monophyly of the two single-VCG formae speciales, lilii and tulipae. Identical genotypes were also found for the three VCGs in F. oxysporum f. sp. spinaciae. In contrast, multiple evolutionary origins were apparent for F. oxysporum f. spp. asparagi, dianthi, gladioli, lini, and opuntiarum, although different VCGs within each of these formae speciales often clustered close together or shared identical EF-1alpha and mtSSU rDNA haplotypes. Kishino-Hasegawa analyses of constraints forcing the monophyly of these formae speciales supported the exclusive origin of F. oxysporum f. sp. opuntiarum but not the monophyly of F. oxysporum f. spp. asparagi, dianthi, gladioli, and lini. Most of the putatively nonpathogenic strains from carnation and lily, representing unique VCGs, were unrelated to F. oxysporum f. spp. dianthi and lilii, respectively. Putatively nonpathogenic or rot-inducing strains did not form exclusive groups within the molecular phylogeny. Parsimony analyses of AFLP fingerprint data supported the gene genealogy-based phylogram; however, AFLP-based phylogenies were considerably more homoplasious than the gene genealogies. The predictive value of the forma specialis naming system within the F. oxysporum complex is questioned.

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Topics: Fusarium oxysporum (56%)

359 Citations


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Open accessJournal ArticleDOI: 10.1073/PNAS.1117018109
Abstract: Six DNA regions were evaluated as potential DNA barcodes for Fungi, the second largest kingdom of eukaryotic life, by a multinational, multilaboratory consortium. The region of the mitochondrial cytochrome c oxidase subunit 1 used as the animal barcode was excluded as a potential marker, because it is difficult to amplify in fungi, often includes large introns, and can be insufficiently variable. Three subunits from the nuclear ribosomal RNA cistron were compared together with regions of three representative protein-coding genes (largest subunit of RNA polymerase II, second largest subunit of RNA polymerase II, and minichromosome maintenance protein). Although the protein-coding gene regions often had a higher percent of correct identification compared with ribosomal markers, low PCR amplification and sequencing success eliminated them as candidates for a universal fungal barcode. Among the regions of the ribosomal cistron, the internal transcribed spacer (ITS) region has the highest probability of successful identification for the broadest range of fungi, with the most clearly defined barcode gap between inter- and intraspecific variation. The nuclear ribosomal large subunit, a popular phylogenetic marker in certain groups, had superior species resolution in some taxonomic groups, such as the early diverging lineages and the ascomycete yeasts, but was otherwise slightly inferior to the ITS. The nuclear ribosomal small subunit has poor species-level resolution in fungi. ITS will be formally proposed for adoption as the primary fungal barcode marker to the Consortium for the Barcode of Life, with the possibility that supplementary barcodes may be developed for particular narrowly circumscribed taxonomic groups.

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Topics: 18S ribosomal RNA (61%), 28S ribosomal RNA (61%), Ribosomal RNA (60%) ...read more

3,444 Citations


Open accessJournal ArticleDOI: 10.1111/J.1364-3703.2011.00783.X
Abstract: The aim of this review was to survey all fungal pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate which fungal pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 495 votes from the international community, and resulted in the generation of a Top 10 fungal plant pathogen list for Molecular Plant Pathology. The Top 10 list includes, in rank order, (1) Magnaporthe oryzae; (2) Botrytis cinerea; (3) Puccinia spp.; (4) Fusarium graminearum; (5) Fusarium oxysporum; (6) Blumeria graminis; (7) Mycosphaerella graminicola; (8) Colletotrichum spp.; (9) Ustilago maydis; (10) Melampsora lini, with honourable mentions for fungi just missing out on the Top 10, including Phakopsora pachyrhizi and Rhizoctonia solani. This article presents a short resume of each fungus in the Top 10 list and its importance, with the intent of initiating discussion and debate amongst the plant mycology community, as well as laying down a bench-mark. It will be interesting to see in future years how perceptions change and what fungi will comprise any future Top 10.

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Topics: Plant Mycology (54%), Puccinia (52%), Phakopsora pachyrhizi (50%)

2,078 Citations


Open accessJournal ArticleDOI: 10.1016/J.MYCRES.2007.03.004
01 May 2007-Fungal Biology
Abstract: A comprehensive phylogenetic classification of the kingdom Fungi is proposed, with reference to recent molecular phylogenetic analyses, and with input from diverse members of the fungal taxonomic community. The classification includes 195 taxa, down to the level of order, of which 16 are described or validated here: Dikarya subkingdom nov.; Chytridiomycota, Neocallimastigomycota phyla nov.; Monoblepharidomycetes, Neocallimastigomycetes class. nov.; Eurotiomycetidae, Lecanoromycetidae, Mycocaliciomycetidae subclass. nov.; Acarosporales, Corticiales, Baeomycetales, Candelariales, Gloeophyllales, Melanosporales, Trechisporales, Umbilicariales ords. nov. The clade containing Ascomycota and Basidiomycota is classified as subkingdom Dikarya, reflecting the putative synapomorphy of dikaryotic hyphae. The most dramatic shifts in the classification relative to previous works concern the groups that have traditionally been included in the Chytridiomycota and Zygomycota. The Chytridiomycota is retained in a restricted sense, with Blastocladiomycota and Neocallimastigomycota representing segregate phyla of flagellated Fungi. Taxa traditionally placed in Zygomycota are distributed among Glomeromycota and several subphyla incertae sedis, including Mucoromycotina, Entomophthoromycotina, Kickxellomycotina, and Zoopagomycotina. Microsporidia are included in the Fungi, but no further subdivision of the group is proposed. Several genera of 'basal' Fungi of uncertain position are not placed in any higher taxa, including Basidiobolus, Caulochytrium, Olpidium, and Rozella.

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Topics: Dikarya (67%), Blastocladiomycota (63%), Mucoromycotina (57%) ...read more

1,928 Citations


Journal ArticleDOI: 10.2307/3761358
Ignazio Carbone1, Linda M. Kohn1Institutions (1)
01 May 1999-Mycologia
Abstract: A simple method is described for designing primer sets that can amplify specific protein-encoding sequences in a wide variety of filamentous ascomycetes. Using this technique, we successfully desig...

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1,779 Citations


Journal ArticleDOI: 10.1017/S0953756201005196
01 Dec 2001-Fungal Biology
Abstract: The ecologically and economically important arbuscular mycorrhizal (AM) fungi, crucial in the ecology and physiology of land plants, and the endocytobiotic fungus, Geosiphon pyriformis, are phylogenetically analysed by their small subunit (SSU) rRNA gene sequences. They can, from molecular, morphological and ecological characteristics, unequivocally be separated from all other major fungal groups in a monophyletic clade. Consequently they are removed from the polyphyletic Zygomycota, and placed into a new monophyletic phylum, the Glomeromycota.The recognition of this monophyletic group, which probably diverged from the same common ancestor as the Ascomycota and Basidiomycota, gives these fungi their proper status, and provides a basis for a new and natural systematics of these fascinating, yet largely hidden organisms, with three new orders (Archaeosporales, Paraglomerales, Diversisporales) described herein. Additionally, several clades resolve at family level; their formal description is in progress.

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Topics: Monophyly (57%), Phylum (57%), Diversisporales (54%) ...read more

1,701 Citations


Performance
Metrics

Author's H-index: 8

No. of papers from the Author in previous years
YearPapers
20002
19991
19983
19972

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Author's top 5 most impactful journals

Mycologia

3 papers, 1.2K citations

Journal of Clinical Microbiology

1 papers, 196 citations

Phytopathology

1 papers, 359 citations

Mycoscience

1 papers, 418 citations

Network Information
Related Authors (2)
Helgard I. Nirenberg

32 papers, 3.3K citations

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Kerry O'Donnell

185 papers, 25.2K citations

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