Search

Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user's needs and established successful practice. In 2013, the Fusarium community voiced near unanimous support for a concept of Fusarium that represented a clade comprising all agriculturally and clinically important Fusarium species, including the F. solani species complex (FSSC). Subsequently, this concept was challenged in 2015 by one research group who proposed dividing the genus Fusarium into seven genera, including the FSSC described as members of the genus Neocosmospora, with subsequent justification in 2018 based on claims that the 2013 concept of Fusarium is polyphyletic. Here, we test this claim and provide a phylogeny based on exonic nucleotide sequences of 19 orthologous protein-coding genes that strongly support the monophyly of Fusarium including the FSSC. We reassert the practical and scientific argument in support of a genus Fusarium that includes the FSSC and several other basal lineages, consistent with the longstanding use of this name among plant pathologists, medical mycologists, quarantine officials, regulatory agencies, students, and researchers with a stake in its taxonomy. In recognition of this monophyly, 40 species described as genus Neocosmospora were recombined in genus Fusarium, and nine others were renamed Fusarium. Here the global Fusarium community voices strong support for the inclusion of the FSSC in Fusarium, as it remains the best scientific, nomenclatural, and practical taxonomic option available. [ABSTRACT FROM AUTHOR]

The fungal genus Massospora (Zoopagomycota: Entomophthorales) includes more than a dozen obligate, sexually transmissible pathogenic species that infect cicadas (Hemiptera) worldwide. At least two species are known to produce psychoactive compounds during infection, which has garnered considerable interest for this enigmatic genus. As with many Entomophthorales, the evolutionary relationships and host associations of Massospora spp. are not well understood. The acquisition of M. diceroproctae from Arizona, M. tettigatis from Chile, and M. platypediae from California and Colorado provided an opportunity to conduct molecular phylogenetic analyses and morphological studies to investigate whether these fungi represent a monophyletic group and delimit species boundaries. In a three-locus phylogenetic analysis including the D1–D2 domains of the nuclear 28S rRNA gene (28S), elongation factor 1 alpha-like (EFL), and beta-tubulin (BTUB), Massospora was resolved in a strongly supported monophyletic group containing four well-supported genealogically exclusive lineages, based on two of three methods of phylogenetic inference. There was incongruence among the single-gene trees: two methods of phylogenetic inference recovered trees with either the same topology as the three-gene concatenated tree (EFL) or a basal polytomy (28S, BTUB). Massospora levispora and M. platypediae isolates formed a single lineage in all analyses and are synonymized here as M. levispora. Massospora diceroproctae was sister to M. cicadina in all three single-gene trees and on an extremely long branch relative to the other Massospora, and even the outgroup taxa, which may reflect an accelerated rate of molecular evolution and/or incomplete taxon sampling. The results of the morphological study presented here indicate that spore measurements may not be phylogenetically or diagnostically informative. Despite recent advances in understanding the ecology of Massospora, much about its host range and diversity remains unexplored. The emerging phylogenetic framework can provide a foundation for exploring coevolutionary relationships with cicada hosts and the evolution of behavior-altering compounds. [ABSTRACT FROM AUTHOR]

Fusarium is a genus of filamentous fungi that contains many agronomically important plant pathogens, mycotoxin producers, and opportunistic human pathogens. Comparative analyses have revealed that the Fusarium genome is compartmentalized into regions responsible for primary metabolism and reproduction (core genome), and pathogen virulence, host specialization, and possibly other functions (adaptive genome). Genes involved in virulence and host specialization are located on pathogenicity chromosomes within strains pathogenic to tomato ( Fusarium oxysporum f. sp. lycopersici) and pea ( Fusarium ' solani' f. sp. pisi). The experimental transfer of pathogenicity chromosomes from F. oxysporum f. sp. lycopersici into a nonpathogen transformed the latter into a tomato pathogen. Thus, horizontal transfer may explain the polyphyletic origins of host specificity within the genus. Additional genome-scale comparative and functional studies are needed to elucidate the evolution and diversity of pathogenicity mechanisms, which may help inform novel disease management strategies against fusarial pathogens. [ABSTRACT FROM AUTHOR]

In this letter, we advocate recognizing the genus Fusarium as the sole name for a group that includes virtually all Fusarium species of importance in plant pathology, mycotoxicology, medicine, and basic research. This phylogenetically guided circumscription will free scientists from any obligation to use other genus names, including teleomorphs, for species nested within this clade, and preserve the application of the name Fusarium in the way it has been used for almost a century. Due to recent changes in the International Code of Nomenclature for algae, fungi, and plants, this is an urgent matter that requires community attention. The alternative is to break the longstanding concept of Fusarium into nine or more genera, and remove important taxa such as those in the F. solani species complex from the genus, a move we believe is unnecessary. Here we present taxonomic and nomenclatural proposals that will preserve established research connections and facilitate communication within and between research communities, and at the same time support strong scientific principles and good taxonomic practice [ABSTRACT FROM AUTHOR]

Members of the Fusarium solani species complex (FSSC), which are morphologically similar but have more than 45 distinct lineages, were chosen as targets for the development of a macroarray detection system that would be broadly adaptable. Thirty-three oligonucleotides (17 to 27 mers) were designed from the internal transcribed spacer (ITS) of the ribosomal RNA genes of 17 FSSC isolates, which belong to 12 phylogenetically closely related species. Of the 33 oligonucleotides on the array, 21 were useful in discriminating all 12 species, some of which had only a single nucleotide difference among them. The high specificity of this method was achieved by optimizing the hybridization temperature and oligo probe length, which had a more substantial effect on the array performance than the melting temperature and the DNA G+C content (GIC%) of the probes. The array was validated by testing inoculated greenhouse samples and diseased field plant samples. [ABSTRACT FROM AUTHOR]

The class Eurotiomycetes (Ascomycota, Pezizomycotina) is a monophyletic group comprising two major clades of very different ascomycetous fungi: (i) the subclass Eurotiomycetidae, a clade that contains most of the fungi previously recognized as Plectomycetes because of their mostly enclosed ascomata and protomnicate asci; and (ii) the subclass Chaetothyriomycetidae, a group of fungi that produce ascomata with an opening reminiscent of those produced by Dothideomycetes or Sordariomycetes. In this paper we use phylogenetic analyses based on data available from the Assembling the Fungal Tree of Life project (AFTOL), in addition to sequences in GenBank, to outline this important group of fungi. The Eurotiomycetidae include producers of toxic and useful secondary metabolites, fermentation agents used to make food products and enzymes, xerophiles and psychrophiles, and the important genetics model Aspergillus nidulans. The Chaetothyriomycetidae include the common black yeast fungi, some of which are pathogens of humans and animals, as well as some primarily lichenized groups newly found to be phylogenetically associated with this group. The recently proposed order Mycocaliciales shows a sister relationship with Eurotiomycetes. The great majority of human pathogenic Pezizomycotina are Eurotiomycetes, particularly in Eurotiales, Onygenales and Chaetothyriales. Due to their broad importance in basic research, industry and public health, several genome projects have focused on species in Onygenales and Eurotiales. [ABSTRACT FROM AUTHOR]

Pythium irregulare is a plant-pathogenic oomycete that causes significant damage to a variety of crops, including ornamentals and vegetables. Morphological as well as molecular studies have reported high levels of genetic diversity within P. irregulare sensu lato which has raised the question as to whether it is a single species or is actually a complex of morphologically similar (cryptic) species. In this study, we used amplified fragment length polymorphism (AFLP) fingerprinting and DNA sequence analysis of the internal transcribed spacer (ITS) region of the ribosomal genes (ITS region) and a portion of the mitochondrial cytochrome oxidase II gene and the spacer region between coxI and coxII to characterize 68 isolates of P. irregulare from the United States. The ITS sequence of a P. irregulare neotype at the CBS collection as well as ITS and coxII sequences for P. irregulare, P. spinosum, and P. sylvaticum from previous studies were included in our analysis. Cluster analysis identified a 19-isolate group (IR-II) that separated itself from the rest of the sample (IR-I). Population structure and sequence analyses supported the distinction of IR-I and IR-II and identified IR-II as P. irregulare sensu stricto. IR-I was designated Pythium sp. clade IR-I. Two insertion/deletion mutations and nine nucleotide substitutions in the ITS region and three in the sequence of coxII and the adjacent spacer region separated the two species. Additionally, they differed significantly (P » 0.01) in the frequency of 182 (77%) AFLP alleles. Gene flow results suggested that P. irregulare sensu stricto and Pythium sp. clade IR-I are cryptic species capable of exchanging favorable alleles (Nm = 0.72). [ABSTRACT FROM AUTHOR]

Tracheomycosis or coffee wilt has emerged as a major disease of robusta coffee in Uganda in the past 10 years. Coffee wilt historically has been associated with Fusarium xylarioides Steyaert (teleomorph Gibberella xylarioides Heim and Sacc.), a species that has been classified as a member of Fusarium section Lateritium. We investigated the molecular phylogenetics of fusarial coffee wilt isolates by generating partial DNA sequences from two protein coding regions, translation elongation factor 1-α and beta-tubulin, in 36 isolates previously identified as F. xylarioides and related fusaria from coffee and other woody hosts, as well as from 12 isolates associated with a current coffee wilt outbreak in Uganda. These isolates fell into two morphologically and phylogenetically distinct groups. The first group was found to represent previously unidentified members of the Gibberella fujikuroi species complex (GFC), a clade that replaces the artificial Fusarium section Liseola. This group of isolates fit the original description of F. xylarioides, thus connecting it to the GFC. The second group, which was diverse in its morphology and DNA sequences, comprised four distinct lineages related to Fusarium lateritium. Our finding of unrelated species associated with coffee wilt disease has important implications regarding its epidemiology, etiology and control. [ABSTRACT FROM AUTHOR]

Accurate identification of Pythium species, the causal agents of Pythium root rot and damping-off of seedlings, and characterization of populations within the species would greatly assist in selecting and implementing control strategies for these pathogens. Several molecular techniques offer methods for accurate and rapid identification of species, but provide little information about their populations. In this study, amplified fragment length polymorphism (AFLP) finger-printing was used to characterize plant-pathogenic Pythium species and intraspecific populations. Species-diagnostic AFLP fingerprints for Pythium aphanidermatum, P. irregulare, and P. ultimum, and tentative fingerprints for six other species, were identified. Intraspecific distance analyses of P. aphanidermatum, P. ultimum, and P. irregulare revealed distinct patterns of intraspecific variation among the three species. P. aphanidermatum showed the smallest mean distance among isolates (15%), followed by P. ultimum (37%). P. irregulare had the largest mean distance among isolates (64%), which were divided into two populations with great genetic differentiation (FST = 0.2), suggesting the presence of a cryptic species boundary within this species. [ABSTRACT FROM AUTHOR]

Presents a study on cryptic speciation and recombination in the aflatoxin-producing fungus aspergillus flavus, a fungus with a uniform asexual morphology. Examination of the grains produced by A. flavus; Information on the test carried out on the assumptions of clonality and conspeciality; Definition of multilocus genotypes.

Recent studies on multiple continents indicate members of the Fusarium tricinctum species complex (FTSC) are emerging as prevalent pathogens of small-grain cereals, pulses, and other economically important crops. These understudied fusaria produce structurally diverse mycotoxins, among which enniatins (ENNs) and moniliformin (MON) are the most frequent and of greatest concern to food and feed safety. Herein a large survey of fusaria in the Fusarium Research Center and Agricultural Research Service culture collections was undertaken to assess species diversity and mycotoxin potential within the FTSC. A 151-strain collection originating from diverse hosts and substrates from different agroclimatic regions throughout the world was selected from 460 FTSC strains to represent the breadth of FTSC phylogenetic diversity. Evolutionary relationships inferred from a five-locus dataset, using maximum likelihood and parsimony, resolved the 151 strains as 24 phylogenetically distinct species, including nine that are new to science. Of the five genes analyzed, nearly full-length phosphate permease sequences contained the most phylogenetically informative characters, establishing its suitability for species-level phylogenetics within the FTSC. Fifteen of the species produced ENNs, MON, the sphingosine analog 2-amino-14,16-dimethyloctadecan-3-ol (AOD), and the toxic pigment aurofusarin (AUR) on a cracked corn kernel substrate. Interestingly, the five earliest diverging species in the FTSC phylogeny (i.e., F. iranicum, F. flocciferum, F. torulosum, and Fusarium spp. FTSC 8 and 24) failed to produce AOD and MON, but synthesized ENNs and/or AUR. Moreover, our reassessment of nine published phylogenetic studies on the FTSC identified 11 additional novel taxa, suggesting this complex comprises at least 36 species. [ABSTRACT FROM AUTHOR]

The author discusses research on analogs of the antifungal drug amphotericin B that retain effectiveness with reduced host toxicities, referencing a study by S. A. Davis published in the journal in 2015. Topics covered include the drug's mode of action, as well as the effect of modified antifungal drug on ergosterol and human cholesterol.

Multilocus DNA sequence data were used to investigate species identity and diversity in two sister clades, the Fusarium concolor (FCOSC) and F. babinda species complexes. Of the 109 isolates analyzed, only 4 were received correctly identified to species and these included 1/46 F. concolor, 1/31 F. babinda, and 2/3 F. anguioides. The majority of the F. concolor and F. babinda isolates were received as F. polyphialidicum, which is a heterotypic synonym of the former species. Previously documented from South America, Africa, Europe, and Australia, our data show that F. concolor is also present in North America. The present study expands the known distribution of F. babinda in Australia to Asia, Europe, and North America. The molecular phylogenetic results support the recognition of a novel Fusarium species within the FCOSC, which is described and illustrated here as F. austroafricanum, sp. nov. It was isolated as an endophyte of kikuyu grass associated with a putative mycotoxicosis of cattle and from plant debris in soil in South Africa. Fusarium austroafricanum is most similar morphologically to F. concolor and F. babinda but differs from the latter two species in producing (i) much longer macroconidia in which the apical cell is blunt to slightly papillate and the basal cell is only slightly notched and (ii) macroconidia via microcycle conidiation on water agar. BLASTn searches of the whole genome sequence of F. austroafricanum NRRL 53441 were conducted to predict mycotoxin potential, using genes known to be essential for the synthesis of several mycotoxins and biologically active metabolites. Based on the presence of intact gene clusters that confer the ability to synthesize mycotoxins and pigments, we analyzed cracked corn kernel cultures of F. austroafricanum via liquid chromatography-mass spectrometry (LC-MS) but failed to detect these metabolites in vitro. [ABSTRACT FROM AUTHOR]

This study was conducted to elucidate evolutionary relationships and species diversity within the Fusarium buharicum species complex (FBSC). We also evaluate the potential of these species to produce mycotoxins and other bioactive secondary metabolites. Maximum likelihood and maximum parsimony analyses of sequences from portions of four marker loci (ITS rDNA, TEF1, RPB1, and RPB2) and the combined 4495 bp data set support recognition of seven genealogically exclusive species within the FBSC. Two of the three newly discovered species are formally described as F. abutilonis and F. guadeloupense based on concordance of gene genealogies and morphological data. Fusarium abutilonis induces leaf, stem, and root lesions on several weedy Malvaceae (Abution theophrasti, Anoda cristata, Sida spinosa) and a fabaceous host (Senna obtusifolia) in North America and also was recovered from soil in New Caledonia. Fusarium abutilonis, together with its unnamed sister, Fusarium sp. ex common marsh mallow (Hibiscus moscheutos) from Washington state, and F. buharicum pathogenic to cotton and kenaf in Russia and Iran, respectively, were strongly supported as a clade of malvaceous pathogens. The four other species of the FBSC are not known to be phytopathogenic; however, F. guadeloupense was isolated from human blood in Texas and soil in Guadeloupe. The former isolate is unique because it represents the only known case of a fusarial infection disseminated hematogenously by a species lacking microconidia and the only documented fusariosis caused by a member of the FBSC. Whole genome sequence data and extracts of cracked maize kernel cultures were analyzed to assess the potential of FBSC isolates to produce mycotoxins, pigments, and phytohormones. [ABSTRACT FROM AUTHOR]

Background Recent work has shown that Fusarium species and genotypes most commonly associated with human infections, particularly of the cornea (mycotic keratitis), are the same as those most commonly isolated from plumbing systems. The species most dominant in plumbing biofilms is Fusarium keratoplasticum, a cosmopolitan fungus known almost exclusively from animal infections and biofilms. To better understand its diversity and population dynamics, we developed and utilized a nine-locus sequence-based typing system to make inferences about clonality, recombination, population structure, species boundaries and hybridization. Results High levels of genetic diversity and evidence for recombination and clonality were detected among 75 clinical and 156 environmental isolates of Fusarium keratoplasticum. The multilocus sequence typing system (MLST) resolved 111 unique nine-locus sequence types (STs). The single locus bifactorial determinants of mating compatibility (mating types MAT1-1 and MAT1-2), were found in a ratio of 70:30. All but one of the 49 isolates of the most common ST (FSSC 2d-2) came from human infections, mostly of the cornea, and from biofilms associated with contact lenses and plumbing surfaces. Significant levels of phylogenetic incongruence were found among loci. Putative clonal relationships among genotypes were estimated, showing a mixture of large clonal complexes and unrelated singletons. Discordance between the nuclear ribosomal rRNA and other gene genealogies is consistent with introgression of ribosomal RNA alleles of phylogenetic species FSSC 9 into F. keratoplasticum. No significant population subdivision based on clinical versus non-clinical sources was found. Conclusions Incongruent phylogenetic trees and the presence of both mating types within otherwise identical STs were observed, providing evidence for sexuality in F. keratoplasticum. Cryptic speciation suggested in a published three-locus MLST system was not supported with the addition of new loci, but evidence of introgression of ribosomal RNA genes from another strongly supported phylogenetic species (FSSC 9), also known from plumbing systems and human infections, was detected in two isolates. Overall, F. keratoplasticum is a diverse and geographically unstructured species with a mixed clonal and recombinant life history. [ABSTRACT FROM AUTHOR]

The online community resource Phytophthora database (PD) was developed to support accurate and rapid identification of Phytophthora and to help characterize and catalog the diversity and evolutionary relationships within the genus. Since its release in 2008. the sequence database has grown to cover 1 to 12 loci for ≈ 2,600 isolates (representing 138 described and provisional species). Sequences of multiple mitochondrial loci were added to complement nuclear loci-based phylogenetic analyses and diagnostic tool development. Key characteristics of most newly described and provisional species have been summarized. Other additions to improve the PD functionality include: (i) geographic information system tools that enable users to visualize the geographic origins of chosen isolates on a global-scale map, (ii) a tool for comparing genetic similarity between isolates via microsatellite markers to support population genetic studies, (iii) a comprehensive review of molecular diagnostics tools and relevant references, (iv) sequence alignments used to develop polymerase chain reaction-based diagnostics tools to support their utilization and new diagnostic tool development, and (v) an online community forum for sharing and preserving experience and knowledge accumulated in the global Phytophthora community. Here we present how these improvements can support users and discuss the PD's future direction. [ABSTRACT FROM AUTHOR]

We constructed several multilocus DNA sequence datasets to assess the phylogenetic diversity of insecticolous fusaria, especially focusing on those housed at the Agricultural Research Service Collection of Entomopathogenic Fungi (ARSEF), and to aid molecular identifications of unknowns via the FUSARIUM-ID and Fusarium MLST online databases and analysis packages. Analyses of a 190-taxon, two-locus dataset, which included 159 isolates from insects, indicated that: (i) insect-associated fusaria were nested within 10 species complexes spanning the phylogenetic breadth of Fusarium, (ii) novel, putatively unnamed insecticolous species were nested within 8/10 species complexes and (iii) Latin binomials could be applied with confidence to only 18/58 phylogenetically distinct fusaria associated with pest insects. Phylogenetic analyses of an 82-taxon, three-locus dataset nearly fully resolved evolutionary relationships among the 10 clades containing insecticolons fusaria. Multilocus typing of isolates within four species complexes identified surprisingly high genetic diversity in that 63/65 of the fusaria typed represented newly discovered haplotypes. The DNA sequence data, together with corrected ABI sequence chromatograms and alignments, have been uploaded to the following websites dedicated to identifying fusaria: FUSARIUM-ID (http://isolate.fusariumdb. org) at Pennsylvania State University's Department of Plant Pathology and Fusarium MLST (http://www. cbs.knaw.nl/fusarium) at the Centraalbureau voor Schimmelcultures (CBS-KNAW) Fungal Biodiversity Center [ABSTRACT FROM AUTHOR]

Plant pathogen culture collections are essential resources in our fight against plant disease and for connecting discoveries of the present with established knowledge of the past. However, available infrastructure in support of culture collections is in serious need of improvement, and we continually face the risk of losing many of these collections. As novel and reemerging plant pathogens threaten agriculture, their timely identification and monitoring depends on rapid access to cultures representing the known diversity of plant pathogens along with genotypic, phenotypic, and epidemiological data associated with them. Archiving such data in a for- mat that can be easily accessed and searched is essential for rapid assessment of potential risk and can help track the change and movement of pathogens. The underexplored pathogen diversity in nature further under- scores the importance of cataloguing pathogen cultures. Realizing the potential of pathogen genomics as a foundation for developing effective disease control also hinges on how effectively we use the sequenced isolate as a reference to understand the genetic and phenotypic diversity within a pathogen species. In this letter, we propose a number of measures for improving pathogen culture collections. [ABSTRACT FROM AUTHOR]

Despite mycologists' interest in its unique spore-dispersal mechanism, systematic studies of the genus Sphaerobolus have received little attention. In our previous work multiple gene genealogies indicated the existence of three divergent lineages in the genus Sphaerobolus, each representing a phylogenetic species. Macro- and micromorphological analyses of colony and fruit-body characters presented here confirmed that these three phylogenetic species correspond to two known species, S. iowensis and S. stellatus, and a newly discovered species. In addition, an expanded gene genealogical analysis is presented for the three species. The new species, named Sphaerobolus ingoldii Geml, Davis et Geiser, is described based on both molecular and morphological data. In addition, while S. iowensis previously had been reported in only two localities, we found that it is as common as or more common than S. stellatus in North America. Despite the considerable amount of DNA polymorhism found in all species, nested clade analyses of S. iowensis and S. stellatus indicated little phylogeographic structure in either species, perhaps due to heavy movement mediated by human activities. [ABSTRACT FROM AUTHOR]

Abstract: Phylogenetic analyses of 27 artillery fungus (Sphaerobolus sp.) isolates were conducted to identify species boundaries in the genus Sphaerobolus. Multiple gene genealogies inferred from maximum likelihood, Bayesian, and maximum-parsimony analyses of sequence data from individual loci (mtSSU, ITS, EF 1-α, and LSU) and a combined dataset (mtSSU, ITS, and EF 1-α) concordantly indicate the existence of three deeply divergent lineages in the genus Sphaerobolus, each representing a phylogenetic species. These three phylogenetic species correspond to two known species: Sphaerobolus iowensis and Sphaerobolus stellatus, and a newly discovered species. Suprageneric phylogenetic analyses of the mtSSU and LSU datasets containing representatives of related genera of the gomphoid–phalloid clade of Homobasidiomycetes suggested that the undescribed taxon likely is more closely related to S. stellatus than to S. iowensis. [Copyright &y& Elsevier]

Species limits were investigated within the Fusarium graminearum clade (Fg clade) through phylogenetic analyses of DNA sequences from portions of 11 nuclear genes including the mating-type (MAT) locus. Nine phylogenetically distinct species were resolved within the Fg clade, and they all possess contiguous MAT1-1 and MAT1-2 idiomorphs consistent with a homothallic reproductive mode. In contrast, only one of the two MAT idiomorphs was found in five other species, four of which were putatively asexual, and the other was heterothallic. Molecular evolutionary analyses indicate the MAT genes are under strong purifying selection and that they are functionally constrained, even in species for which a sexual state is unknown. The phylogeny supports a monophyletic and apomorphic origin of homothallism within this clade. Morphological analyses demonstrate that a combination of conidial characters could be used to differentiate three species and three species pairs. Species rank is formally proposed for the eight unnamed species within the Fg clade using fixed nucleotide characters.Index Descriptors: Fusarium head blight; Mating-type; Histone H3; Homothallic; Heterothallic; Gene trees; Species trees; Species limits; Phylogeny; Reciprocal monophyly [Copyright &y& Elsevier]

The Ambrosia Fusarium Clade (AFC) is a monophyletic lineage within clade 3 of the Fusarium solani species complex (FSSC) that currently comprises 19 genealogically exclusive species. These fungi are known or predicted to be farmed by adult female Euwallacea ambrosia beetles as a nutritional mutualism (Coleoptera: Scolytinae; Xyleborini). To date, only eight of the 19 AFC species have been described formally with Latin binomials. We describe three AFC species, previously known as AF-8, AF-10, and AF-11, based on molecular phylogenetic analysis of multilocus DNA sequence data and comparative morphological/phenotypic studies. Fusarium duplospermum (AF-8) farmed by E. perbrevis on avocado in Florida, USA, is distinguished by forming two morphologically different types of multiseptate conidia and brownish orange colonies on potato dextrose agar (PDA). Fusarium drepaniforme (AF-10), isolated from an unknown woody host in Singapore and deposited as Herb IMI 351954 in the Royal Botanic Gardens, Kew, UK, under the name F. bugnicourtii, is diagnosed by frequent production of multiseptate sickle-shaped conidia. Fusarium papillatum (AF-11), isolated from mycangia of E. perbrevis infesting tea in Kandy, Sri Lanka, forms multiseptate clavate conidia that possess a papillate apical cell protruding toward the ventral side. Lastly, we prepared an augmented description of F. kuroshium (AF-12), previously isolated from the heads or galleries of E. kuroshio in a California sycamore tree, El Cajon, California, USA, and recently validated nomenclaturally as Fusarium. Conidia formed by F. kuroshium vary widely in size and shape, suggesting a close morphological relationship with F. floridanum, compared with all other AFC species. Maximum likelihood and maximum parsimony analyses of a multilocus data set resolve these three novel AFC species, and F. kuroshium, as phylogenetically distinct based on genealogical concordance. Given the promiscuous nature of several Euwallacea species, and the overlapping geographic range of several AFC species and Euwallacea ambrosia beetles, the potential for symbiont switching among sympatric species is discussed. [ABSTRACT FROM AUTHOR]

Support values above internodes are Bayesian posterior probabilities (BPP)/maximum likelihood bootstrap (ML-BS) values. Support values above internodes are Bayesian posterior probabilities (BPP)/maximum likelihood bootstrap (ML-BS) values. Support values above internodes are Bayesian posterior probabilities (BPP)/maximum likelihood bootstrap (ML-BS) values. [Extracted from the article]

The Fusarium sambucinum species complex (FSAMSC) is one of the most taxonomically challenging groups of fusaria, comprising prominent mycotoxigenic plant pathogens and other species with various lifestyles. Among toxins produced by members of the FSAMSC, trichothecenes pose the most significant threat to public health. Herein a global collection of 171 strains, originating from diverse hosts or substrates, were selected to represent FSAMSC diversity. This strain collection was used to assess their species diversity, evaluate their potential to produce trichothecenes, and cause disease on wheat. Maximum likelihood and Bayesian analyses of a combined 3-gene dataset used to infer evolutionary relationships revealed that the 171 strains originally received as 48 species represent 74 genealogically exclusive phylogenetically distinct species distributed among six strongly supported clades: Brachygibbosum, Graminearum, Longipes, Novel, Sambucinum, and Sporotrichioides. Most of the strains produced trichothecenes in vitro but varied in type, indicating that the six clades correspond to type A, type B, or both types of trichothecene-producing lineages. Furthermore, five strains representing two putative novel species within the Sambucinum Clade produced two newly discovered type A trichothecenes, 15-keto NX-2 and 15-keto NX-3. Strains of the two putatively novel species together with members of the Graminearum Clade were aggressive toward wheat when tested for pathogenicity on heads of the susceptible cultivar Apogee. In planta, the Graminearum Clade strains produced nivalenol or deoxynivalenol and the aggressive Sambucinum Clade strains synthesized NX-3 and 15-keto NX-3. Other strains within the Brachygibbosum, Longipes, Novel, Sambucinum, and Sporotrichioides Clades were nonpathogenic or could infect the inoculated floret without spreading within the head. Moreover, most of these strains did not produce any toxin in the inoculated spikelets. These data highlight aggressiveness toward wheat appears to be influenced by the type of toxin produced and that it is not limited to members of the Graminearum Clade. [ABSTRACT FROM AUTHOR]

True fungi (Fungi) and fungus-like organisms (e.g. Mycetozoa, Oomycota) constitute the second largest group of organisms based on global richness estimates, with around 3 million predicted species. Compared to plants and animals, fungi have simple body plans with often morphologically and ecologically obscure structures. This poses challenges for accurate and precise identifications. Here we provide a conceptual framework for the identification of fungi, encouraging the approach of integrative (polyphasic) taxonomy for species delimitation, i.e. the combination of genealogy (phylogeny), phenotype (including autecology), and reproductive biology (when feasible). This allows objective evaluation of diagnostic characters, either phenotypic or molecular or both. Verification of identifications is crucial but often neglected. Because of clade-specific evolutionary histories, there is currently no single tool for the identification of fungi, although DNA barcoding using the internal transcribed spacer (ITS) remains a first diagnosis, particularly in metabarcoding studies. Secondary DNA barcodes are increasingly implemented for groups where ITS does not provide sufficient precision. Issues of pairwise sequence similarity-based identifications and OTU clustering are discussed, and multiple sequence alignment-based phylogenetic approaches with subsequent verification are recommended as more accurate alternatives. In metabarcoding approaches, the trade-off between speed and accuracy and precision of molecular identifications must be carefully considered. Intragenomic variation of the ITS and other barcoding markers should be properly documented, as phylotype diversity is not necessarily a proxy of species richness. Important strategies to improve molecular identification of fungi are: (1) broadly document intraspecific and intragenomic variation of barcoding markers; (2) substantially expand sequence repositories, focusing on undersampled clades and missing taxa; (3) improve curation of sequence labels in primary repositories and substantially increase the number of sequences based on verified material; (4) link sequence data to digital information of voucher specimens including imagery. In parallel, technological improvements to genome sequencing offer promising alternatives to DNA barcoding in the future. Despite the prevalence of DNA-based fungal taxonomy, phenotype-based approaches remain an important strategy to catalog the global diversity of fungi and establish initial species hypotheses. [ABSTRACT FROM AUTHOR]

The Ambrosia Fusarium Clade (AFC) comprises at least 16 genealogically exclusive species-level lineages within clade 3 of the Fusarium solani species complex (FSSC). These fungi are either known or predicted to be farmed by Asian Euwallacea ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) in the tribe Xyleborini as a source of nutrition. To date, only 4 of the 16 AFC lineages have been described formally. In the absence of Latin binomials, an ad hoc nomenclature was developed to distinguish the 16 species lineages as AF-1 to AF-16. Herein, Fusarium species AF-3, AF-5, and AF-7 were formally described as F. floridanum, F. tuaranense, and F. obliquiseptatum, respectively. Fusarium floridanum farmed by E. interjectus on box elder (Acer negundo) in Gainesville, Florida, was distinguished morphologically by the production of sporodochial conidia that were highly variable in size and shape together with greenish-pigmented chlamydospores. Fusarium tuaranense was isolated from a beetle-damaged Paŕa rubber tree (Hevea brasiliense) in North Borneo, Malaysia, and was diagnosed by production of the smallest sporodochial conidia of any species within the AFC. Lastly, F. obliquiseptatum was farmed by an unnamed ambrosia beetle designated Euwallacea sp. 3 (E. fornicatus species complex) on avocado (Persea americana) in Queensland, Australia. It uniquely produces some clavate sporodochial conidia with oblique septa. Maximum likelihood analysis of a multilocus data set resolved these three novel AFC taxa as phylogenetically distinct species based on genealogical concordance. Particularly where introduced into exotic environments, these exotic mutualists pose a serious threat to the avocado industry, native forests, and urban landscapes in diverse regions throughout the world. [ABSTRACT FROM AUTHOR]

Fusarium oxysporum f. sp. cubense Tropical Race 4 (Foc TR4) is threatening banana production worldwide. Despite quarantine efforts, the pathogen continues to spread; thus, early diagnosis plays an essential role for the proper execution of contingency plans. Here, we assess the accuracy of four PCR-based molecular methods described in the literature for the identification and detection of race 4 strains, including Subtropical (Foc STR4) and Tropical Race 4 causing Fusarium wilt of banana. We screened a total of 302 isolates using these four markers, and performed phylogenetic analyses, Vegetative Compatibility Group (VCG) testing, sequence comparison, and pathogenicity tests for selected isolates. Our results show that three out of the four markers tested are not reliable for identification of Foc STR4 and TR4, as DNA from isolates from Ecuador, pathogenic and nonpathogenic to banana, obtained from different banana cultivars, displayed cross-reaction with these methods; that is, false positives can occur during the diagnostic process for race 4. Phylogenetic analyses, VCG testing, sequence comparison, and pathogenicity tests suggest the presence of non-target F. oxysporum isolates that share genomic regions with pathogenic strains but lack true pathogenicity to banana. The findings of this work are of foremost importance for international regulatory agencies performing surveillance tests in pathogen-free areas using the current diagnostic methods. We suggest the use of a genetic locus possibly related to virulence, previously identified by T-DNA, and amplified with primers W2987F/ W2987R, for diagnosis of Foc TR4 as the most reliable alternative. We urge the adoption of a more holistic view in the study of F. oxysporum as a plant pathogen that considers the biology and diversity of the species for the development of better diagnostic tools. [ABSTRACT FROM AUTHOR]

Draft genomes of the fungal species Fusarium xylarioides, Teratosphaeria gauchensis and T. zuluensis are presented. In addition an annotation of the genome of Ceratocystis fimbriata is presented. Overall these genomes provide a valuable resource for understanding the molecular processes underlying pathogenicity and potential management strategies of these economically important fungi. [ABSTRACT FROM AUTHOR]

The article offers information on the ecology and epidemiology of an emerging fungal disease in the wildlife. Topics discussed include information on the consequences for biodiversity and ecosystem health; discussions on the impacts of white-nose syndrome on the bats population in North America; discussions on the effective management strategies for the control pf the pathogens causing fungal diseases.

This study was conducted to determine the species identity and mycotoxin potential of 158 Fusarium strains originally archived in the South African Medical Research Council's Mycotoxigenic Fungal Collection (MRC) that were reported to comprise 17 morphologically distinct species in the classic 1984 compilation by Marasas et al., Toxigenic Fusarium Species: Identity and Mycotoxicology. Maximum likelihood and maximum parsimony molecular phylogenetic analyses of single and multilocus DNA sequence data indicated that the strains represented 46 genealogically exclusive phylogenetically distinct species distributed among eight species complexes. Moreover, the phylogenetic data revealed that 80/158 strains were received under a name that is not accepted today (ex F. moniliforme) or classified under a different species name. In addition, gas chromatography-mass spectrometry (GC-MS) and/or high-performance liquid chromatography-mass spectrometry (HPLC-MS)-based mycotoxin analyses were conducted to determine which toxins the strains could produce in liquid and/or solid cultures. All of the trichothecene toxin-producing fusaria were nested within the F. sambucinum (FSAMSC) or F. incarnatum-equiseti (FIESC) species complexes. Consistent with this finding, GC-MS analyses detected trichothecenes in agmatine-containing broth or rice culture extracts of all 13 FSAMSC and 10/12 FIESC species tested. Species in six and seven of the eight species complexes were able to produce moniliformin and beauvericin, respectively, whereas B-type fumonisins were only detected in extracts of cracked maize kernel cultures of three species in the F. fujikuroi (FFSC) species complex. [ABSTRACT FROM AUTHOR]

Surveys for crown rot (FCR) and head blight (FHB) of Algerian wheat conducted during 2014 and 2015 revealed that Fusarium culmorum strains producing 3-acetyl-deoxynivalenol (3ADON) or nivalenol (NIV) were the causal agents of these important diseases. Morphological identification of the isolates ( n FCR = 110, n FHB = 30) was confirmed by sequencing a portion of TEF1 . To assess mating type idiomorph, trichothecene chemotype potential and global population structure, the Algerian strains were compared with preliminary sample of F. culmorum from Italy ( n = 27), Australia ( n = 30) and the United States ( n = 28). A PCR assay for MAT idiomorph revealed that MAT1-1 and MAT1-2 strains were segregating in nearly equal proportions, except within Algeria where two-thirds of the strains were MAT1-2 . An allele-specific PCR assay indicated that the 3ADON trichothecene genotype was predominant globally (83.8% 3ADON) and in each of the four countries sampled. In vitro toxin analyses confirmed trichothecene genotype PCR data and demonstrated that most of the strains tested (77%) produced culmorin. Global population genetic structure of 191 strains was assessed using nine microsatellite markers (SSRs). AMOVA of the clone corrected data indicated that 89% of the variation was within populations. Bayesian analysis of the SSR data identified two globally distributed, sympatric populations within which both trichothecene chemotypes and mating types were represented. [ABSTRACT FROM AUTHOR]

Fusisporium solani was described as the causal agent of a dry rot of potato in Germany in the mid 19th century. As Fusarium solani, the species became known as a plurivorous plant pathogen, endophyte, decomposer, and opportunistic pathogen of humans and nutritional symbiont of insects. In parallel, it became evident that the morphologically defined species F. solani represents a phylogenetically and biologically complex group of often morphologically cryptic species that has come to be known in part as the F. solani species complex (FSSC), accommodating several formae speciales and mating populations/biological species. The FSSC currently includes more than 60 phylogenetic species. Several of these have been named, but the majority remains unnamed and the identity of F. solani sensu stricto is unclear. To promote further taxonomic developments in the FSSC, lectoand epitypification is proposed for Fusisporium solani. Although no type material for F. solani is known to exist, the species was abundantly illustrated in the protologue. Thus, a relevant illustration provided by von Martius is selected as the lectotype. The epitype selected here originates from a rotting potato collected in a field in Slovenia. This strain causes a dry rot of artificially inoculated potatoes. It groups in the heretofore unnamed phylogenetic species 5, which is nested within clade 3 of the FSSC (FSSC 5). Members of this phylogenetic species have a wide geographic distribution and include soil saprotrophs and plant and opportunistic human pathogens. This typification is consistent with the original description of Fusisporium solani and the concept of F. solani as a widely distributed soil inhabitant and pathogen. [ABSTRACT FROM AUTHOR]

The mutualism between xyleborine beetles in the genus Euwallacea (Coleoptera: Curculionidae: Scolytinae) and members of the Ambrosia Fusarium Clade (AFC) represents one of 11 known evolutionary origins of fungiculture by ambrosia beetles. Female Euwallacea beetles transport fusarial symbionts in paired mandibular mycangia from their natal gallery to woody hosts where they are cultivated in galleries as a source of food. Native to Asia, several exotic Euwallacea species were introduced into the United States and Israel within the past two decades and they now threaten urban landscapes, forests and avocado production. To assess species limits and to date the evolutionary diversification of the mutualists, we reconstructed the evolutionary histories of key representatives of the Fusarium and Euwallacea clades using maximum parsimony and maximum likelihood methods. Twelve species-level lineages, termed AF 1–12, were identified within the monophyletic AFC and seven among the Fusarium -farming Euwallacea . Bayesian diversification-time estimates placed the origin of the Euwallacea – Fusarium mutualism near the Oligocene–Miocene boundary ∼19–24 Mya. Most Euwallacea spp. appear to be associated with one species of Fusarium , but two species farmed two closely related fusaria. Euwallacea sp. #2 in Miami-Dade County, Florida cultivated Fusarium spp. AF-6 and AF-8 on avocado, and Euwallacea sp. #4 farmed Fusarium ambrosium AF-1 and Fusarium sp. AF-11 on Chinese tea in Sri Lanka. Cophylogenetic analyses indicated that the Euwallacea and Fusarium phylogenies were largely incongruent, apparently due to the beetles switching fusarial symbionts (i.e., host shifts) at least five times during the evolution of this mutualism. Three cospeciation events between Euwallacea and their AFC symbionts were detected, but randomization tests failed to reject the null hypothesis that the putative parallel cladogenesis is a stochastic pattern. Lastly, two collections of Euwallacea sp. #2 from Miami-Dade County, Florida shared an identical cytochrome oxidase subunit 1 (CO1) allele with Euwallacea validus , suggesting introgressive hybridization between these species and/or pseudogenous nature of this marker. Results of the present study highlight the importance of understanding the potential for and frequency of host-switching between Euwallacea and members of the AFC, and that these shifts may bring together more aggressive and virulent combinations of these invasive mutualists. [ABSTRACT FROM AUTHOR]

Fungi that have the enzymes cyanase and carbonic anhydrase show a limited capacity to detoxify cyanate, a fungicide employed by both plants and humans. Here, we describe a novel two-gene cluster that comprises duplicated cyanase and carbonic anhydrase copies,which we name the CCA gene cluster, trace its evolution across Ascomycetes, and examine the evolutionary dynamics of its spread among lineages of the Fusarium oxysporum species complex (hereafter referred to as the FOSC), a cosmopolitan clade of purportedly clonal vascular wilt plant pathogens. Phylogeneticanalysis of fungal cyanase and carbonic an hydrase genes reveals that the CCA gene cluster arose independently at least twice and is now present in three lineages, namely Cochliobolus lunatus, Oidiodendron maius, and the FOSC. Genome-wide surveys within the FOSC indicate that the CCA gene cluster varies in copy number a cross isolates, is always located on accessory chromosomes, and is absent in FOSC's closest relatives. Phylogenetic reconstruction of the CCA gene cluster in163 FOSC strains from a wide variety of hosts suggests are cent history of rampant transfers between isolates. We hypothesize that the independent formation of the CCA gene cluster in different fungal lineages and its spread across FOSC strains may be associated with resistance to plant-produced cyanates or to use of cyanate fungicides in agriculture. [ABSTRACT FROM AUTHOR]

The B trichothecene toxin-producing clade (B clade) of Fusarium includes the etiological agents of Fusarium head blight, crown rot of wheat and barley and stem and ear rot of maize. B clade isolates also have been recovered from several wild and cultivated grasses, including Dactylis glomerata (orchard grass or cock's foot), one of the world's most important forage grasses. Two isolates from the latter host are formally described here as F. dactylidis. Phenotypically F. dactylidis most closely resembles F. ussurianum from the Russian Far East. Both species produce symmetrical sporodochial conidia that are similar in size and curved toward both ends.However, conidia of F. ussurianum typically end in a narrow apical beak while the apical cell of F. dactylidis is acute. Fusarium dactylidis produced nivalenol mycotoxin in planta as well as low but detectable amounts of the estrogenic mycotoxin zearalenone in vitro. Results of a pathogenicity test revealed that F. dactylidis induced mild head blight on wheat. [ABSTRACT FROM AUTHOR]

With the recent changes concerning pleomorphic fungi in the new International Code of Nomenclature for algae, fungi, and plants (ICN), it is necessary to propose the acceptance or protection of sexual morph-typified or asexual morph-typified generic names that do not have priority, or to propose the rejection or suppression1 of competing names. In addition, sexual morph-typified generic names, where widely used, must be proposed for rejection or suppression in favour of asexual morph-typified names that have priority, or the latter must be proposed for conservation or protection. Some pragmatic criteria used for deciding the acceptance or rejection of generic names include: the number of name changes required when one generic name is used over another, the clarity of the generic concept, their relative frequencies of use in the scientific literature, and a vote of interested mycologists. Here, twelve widely used generic names in three families of Hypocreales are proposed for acceptance, either by conservation or protection, despite their lack of priority of publication, or because they are widely used asexual morph-typified names. Each pair of generic names is evaluated, with a recommendation as to the generic name to be used, and safeguarded, either through conservation or protection. Four generic names typified by a species with a sexual morph as type that are younger than competing generic names typified by a species with an asexual morph type, are proposed for use. Eight older generic names typified by species with an asexual morph as type are proposed for use over younger competing generic names typified by a species with a sexual morph as type. Within Bionectriaceae, Clonostachys is recommended over Bionectria; in Hypocreaceae, Hypomyces is recommended over Cladobotryum, Sphaerostilbella over Gliocladium, and Trichoderma over Hypocrea; and in Nectriaceae, Actinostilbe is recommended over Lanatonectria, Cylindrocladiella over Nectricladiella, Fusarium over Gibberella, Gliocephalotrichum over Leuconectria, Gliocladiopsis over Glionectria, Nalanthamala over Rubrinectria, Nectria over Tubercularia, and Neonectria over Cylindrocarpon. [ABSTRACT FROM AUTHOR]

Abstract: Fusarium species are frequently associated with mycotic keratitis and, to a lesser extent, cases of localized and disseminated infections. The Fusarium solani species complex (FSSC) is the most common group of fusaria associated with human infectious diseases. Several studies to date have revealed dozens of strongly supported phylogenetic species within this important evolutionary clade, though little work has been done to improve the taxonomy and understanding of the reproductive mode and phenotypes of the predominant clinically relevant species. Here we described Fusarium keratoplasticum sp. nov., and Fusarium petroliphilum stat. nov., two phylogenetic species that are among the most frequently isolated fusaria in plumbing drain biofilms and outbreaks of contact lens-associated mycotic keratitis. F. keratoplasticum isolates were highly variable and showed a range of morphological characteristics typical for most classical concepts of ‘F. solani.’ Many isolates failed to produce sporodochia and macroconidia. Although most attempts to sexually cross F. keratoplasticum isolates failed, a heterothallic sexual stage typical for the FSSC was discovered by pairing isolates of opposite mating type on V-8 agar, the ascospores of which showed molecular evidence of recombination. Secondary metabolite profiles of FSSC species defined through molecular data were compared for the first time and revealed the production of bioactive compounds including cyclosporines and several novel compounds of unknown function. We speculate that the inferred phenotypic variability in these species is the result of the almost entirely anthropogenic sources from which they are derived, including biofilms on plumbing systems. [Copyright &y& Elsevier]

During a survey for pathogens of Florida torreya (Torreya taxifolia) in 2009, a novel Fusarium species was isolated from cankers affecting this critically endangered conifer whose current range is restricted to northern Florida and southwestern Georgia. Published multilocus molecular phylogenetic analyses indicated that this pathogen represented a genealogically exclusive, phylogenetically distinct species representing one of the earliest divergences within the Gibberella clade of Fusarium. Furthermore, completion of Koch's postulates established that this novel species was the causal agent of Florida torreya canker disease. Here we formally describe this pathogen as a new species, Fusarium torreyae. Pure cultures of this species produced long and slender multiseptate sporodochial conidia that showed morphological convergence with two distantly related fusaria, reflecting the homoplasious nature of Fusarium conidial morphology. [ABSTRACT FROM AUTHOR]

Abstract: Fusarium (Hypocreales, Nectriaceae) is one of the most economically important and systematically challenging groups of mycotoxigenic phytopathogens and emergent human pathogens. We conducted maximum likelihood (ML), maximum parsimony (MP) and Bayesian (B) analyses on partial DNA-directed RNA polymerase II largest (RPB1) and second largest subunit (RPB2) nucleotide sequences of 93 fusaria to infer the first comprehensive and well-supported phylogenetic hypothesis of evolutionary relationships within the genus and 20 of its near relatives. Our analyses revealed that Cylindrocarpon formed a basal monophyletic sister to a ‘terminal Fusarium clade’ (TFC) comprising 20 strongly supported species complexes and nine monotypic lineages, which we provisionally recognize as Fusarium (hypothesis F1). The basal-most divergences within the TFC were only significantly supported by Bayesian posterior probabilities (B-PP 0.99–1). An internode of the remaining TFC, however, was strongly supported by MP and ML bootstrapping and B-PP (hypothesis F2). Analysis of seven Fusarium genome sequences and Southern analysis of fusaria elucidated the distribution of genes required for synthesis of 26 families of secondary metabolites within the phylogenetic framework. Diversification time estimates date the origin of the TFC to the middle Cretaceous 91.3million years ago. We also dated the origin of several agriculturally important secondary metabolites as well as the lineage responsible for Fusarium head blight of cereals. Dating of several plant-associated species complexes suggests their evolution may have been driven by angiosperm diversification during the Miocene. Our results support two competing hypotheses for the circumscription of Fusarium and provide a framework for future comparative phylogenetic and genomic analyses of this agronomically and medically important genus. [Copyright &y& Elsevier]

A large collection of strains belonging to the Fusarium solani species complex (FSSC) was isolated from soil and perithecia in primap/ forests in Sri Lanka (from fallen tree bark) and tropical Australia (Queensland, from fallen tree fruits and nuts). Portions of the translation elongation factor 1-alpha (tef1) gene, the nuclear large subunit (NLSU) and internal transcribed spacer regions (ITS) of the nuclear ribosomal RNA genes were sequenced in 52 isolates from soil and perithecia. The FSSC was divided previously into three clades with some biogeographic structure, termed Clades 1, 2 and 3. MI Sri Lankan and Australian soil isolates were found to be members of Clade 3, most grouping with the cosmopolitan soil-associated species F. falciforme. All but two Sri Lankan perithecial isolates were associated with a set of five divergent phylogenetic lineages that were associated with Clade 2. Australian perithecial isolates resided in a subclade of Clade 3 where most of the previously defined mating populations of the FSSC reside. Isolates from perithecia and those cultured from soil were always members of different species lineages, even when derived from proximal locations. The previous biogeographic assignment of Clade 2 to South America is now expanded to the worldwide tropics. Sri Lanka appears to be an important center of diversity for the FSSC. Nectria haematococca is epitypified with a collection from the type locality in Sri Lanka; its anamorph is described as a new species, Fusarium haematococcum. Neocosmospora E.F. Smith is adopted as the correct genus for Nectria haematococca. These new species are described: F. kurunegalense/Neo, kurunegalensis, F. rectiphorus/ Neo. rectiphora/, F. mahasenii/Neo. mahasenii/, F. kelerajum/Neo, keleraja. [ABSTRACT FROM AUTHOR]

Background. Filamentous fungi of the genera Aspergillus and Fusarium are major causes of corneal ulcers in the United States and in the developing world and result in significant visual impairment and blindness. Methods. RNA was extracted from 110 patients with corneal ulcers in southern India within 1 week of infection with either Fusarium solani or Aspergillus flavus, and gene expression was determined by quantitative polymerase chain reaction. Posttransplant corneas from later stage disease (>2 weeks after infection) were also examined. Results. Expression of Dectin-1, Toll-like receptor 2 (TLR2), TLR4, TLR9, and NOD-like receptor protein (NLRP)3 messenger RNA was elevated >1000-fold compared with uninfected donor corneas, whereas Dectin-2 was constitutively expressed in uninfected corneas. Furthermore, interleukin 1β (IL-1β) expression was elevated >1000-fold, whereas IL-1α expression was not increased. Expression of IL-8, IL-17, and tumor necrosis factor α was also elevated. CD3+and CD4+ T cells were detected in infected posttransplant corneas. Expression of IL-17 and interferon γ was elevated but not that of IL-4. There were no significant differences in the host response between Aspergillus- and Fusarium-infected corneas at any time point. Conclusions. There is a common innate and adaptive immune response to these filamentous fungi, which includes the generation of T-helper 1 and T-helper 17 cells. [ABSTRACT FROM AUTHOR]

Sequences of selected marker loci have been widely used for the identification of specific pathogens and the development of sequence-based diagnostic methods. Although such approaches offer several advantages over traditional culture-based methods for pathogen diagnosis and identification, they have their own pitfalls. These include erroneous and incomplete data in reference databases, poor or oversimplified interpretation of search results, and problems associated with defining species boundaries. In this letter, we outline the potential benefits and drawbacks of using sequence data for identification and taxonomic deductions of plant-pathogenic fungi and oomycetes, using Phytophthora as a primary example. We also discuss potential remedies for these pitfalls and address why coordinated community efforts are essential to make such remedies more efficient and robust. [ABSTRACT FROM AUTHOR]

The Mediterranean island of Sardinia is well known for high levels of vascular plant diversity and endemism, but little is known about its microbial diversity. Under the hypothesis that Fusarium species would show similarly high diversity, we estimated variability in Fusarium species composition among 10 sites around the island. Markers previously adopted for multilocus sequence typing (MLST) were used to determine multilocus DNA sequence haplotypes for 263 Fusarium isolates. In addition portions of the translation elongation factor 1-alpha and second largest RNA polymerase subunit genes were sequenced for all isolates. The intergenic spacer (IGS) region of the nuclear ribosomal RNA gene repeat was sequenced for members of the F. oxysporum species complex (FOSC), and a portion of the nuclear ribosomal RNA gene repeat comprising the internal transcribed spacer (ITS) and part of the large nuclear ribosomal RNA subunit was sequenced for members of the F. solani species complex (FSSC). Seventy-three multilocus haplotypes were identified among the 263 isolates typed, of which 48 represented FOSC and FSSC. Thirty-seven of 48 FOSC two-locus and FSSC three-locus haplotypes had not been observed previously. The 38 non-FOSC/FSSC fusaria comprised 25 haplotypes distributed among 10 species, five of which appear to represent novel, phylogenetically distinct species. In general newly discovered haplotypes were restricted to one or a few sites. All FSSC isolates represented new haplotypes in phylogenetic species FSSC 5 and 9, which differ from the phylogenetic species dominant in soils worldwide. No obvious correlations were found between haplo-type diversity and geospatial or habitat distribution. Overall these results indicate a high degree of Fusarium genetic diversity on multiple geographic scales within Sardinia. These results contrast with recent work showing that common, cosmopolitan species dominate Sardinia's Trichoderma biodiversity. All data are available for access and viewing from the FUSARIUM-ID database. [ABSTRACT FROM AUTHOR]

Abstract: We constructed a two-locus database, comprising partial translation elongation factor (EF-1α) gene sequences and nearly full-length sequences of the nuclear ribosomal intergenic spacer region (IGS rDNA) for 850 isolates spanning the phylogenetic breadth of the Fusarium oxysporum species complex (FOSC). Of the 850 isolates typed, 101 EF-1α, 203 IGS rDNA, and 256 two-locus sequence types (STs) were differentiated. Analysis of the combined dataset suggests that two-thirds of the STs might be associated with a single host plant. This analysis also revealed that the 26 STs associated with human mycoses were genetically diverse, including several which appear to be nosocomial in origin. A congruence analysis, comparing partial EF-1α and IGS rDNA bootstrap consensus, identified a significant number of conflicting relationships dispersed throughout the bipartitions, suggesting that some of the IGS rDNA sequences may be non-orthologous. We also evaluated enniatin, fumonisin and moniliformin mycotoxin production in vitro within a phylogenetic framework. [Copyright &y& Elsevier]

The morphospecies Fusarium dimerum, known only from its anamorph, comprises at least 12 phylogenetically distinct species. Analyses of the large subunit ribosomal DNA (LSU rDNA) show they are taxa of the Nectriaceae (Hypocreales), related to F. domesticum and form a phylogenetically distinct clade within Fusarium. Fusarium dimerum, for which no herbarium material could be located, is characterized by macroconidia with a single, median septum, according to the original description and illustration. Fusarium lunatum (= F. dimerum vat. violaceum) forms similar but longer macroconidia and purple, catenate or clustered chlamydospores. Fusarium delphinoides SP- nov., F. biseptatum sp. nov., F. penzigii sp. nov., F. nectrioides comb. nov. (= F. dimerum var. nectrioides) and two unnamed Fusarium spp. produce macroconidia with mostly two or rarely three septa. The name F. dimerum, which originally was applied to a fungus from a citron, is used for a taxon including isolates causing infections in immunocompetent and immunocompromised patients. Fusarium nectrioides, F. delphinoides, F. penzigii and F. biseptatum are known from soil and dead plant substrata or rarely as agents of trauma-related eye infections of humans. Fusarium lunatum is an inhabitant of the cladodes of species within the cactus genera Opuntia and Gymnocalycium. Its unnamed closest sister taxon, which also forms 1-septate macroconidia and purple, clustered chlamydospores, was isolated from a human sinus. Fusarium delphinoides is a pathogen of the cactus-like African species Hoodia gordonii (Apocynaceae). Phylogenetic analyses based on combined sequences of the internal transcribed spacer region, LSU rDNA and partial sequences of the elongation factor 1-alpha and beta-tubulin genes identified a clade of several species producing predominately 2-septate macroconidia as the reciprocally monophyletic sister of F. dimerum. The basal sister group of the two aforementioned clades includes Fusarium lunatum and two undescribed species, all of which form 1-septate macroconidia. [ABSTRACT FROM AUTHOR]

Phytophthora spp. represent a serious threat to agricultural and ecological systems. Many novel Phytophthora spp. have been reported in recent years, which is indicative of our limited understanding of the ecology and diversity of Phytophthora spp. in nature. Systematic cataloging of genotypic and phenotypic information on isolates of previously described species serves as a baseline for identification, classification, and risk assessment of new Phytophthora isolates. The Phytophthora Database (PD) was established to catalog such data in a web-accessible and searchable format. To support the identification of new Phytophthora isolates via comparison of their sequences at one or more loci with the corresponding sequences derived from the isolates archived in the PD, we generated and deposited sequence data from more than 1,500 isolates representing the known diversity in the genus. Data search and analysis tools in the PD include BLAST, Phyloviewer (a program for building phylogenetic trees using sequences of selected isolates), and Virtual Gel (a program for generating expected restriction patterns for given sequences). The PD also provides a customized means of storing and sharing data via the web. The PD serves as a model that easily can be adopted to develop databases for other important pathogen groups. [ABSTRACT FROM AUTHOR]

Abstract: Analysis of Fusarium head blight (FHB) pathogen diversity revealed that 3ADON producing Fusarium graminearum are prevalent in North America and identified significant population structure associated with trichothecene chemotype differences (F ST >0.285; P <0.001). In addition, we identified a trichothecene chemotype cline in Canada and documented a recent and significant shift in FHB pathogen composition by demonstrating that the 3ADON chemotype frequency in western Canada increased more than 14-fold between 1998 and 2004. On average, isolates from 3ADON populations produced significantly (P <0.05) more trichothecene and had significantly (P <0.005) higher fecundity and growth rates than isolates from the 15ADON population. These results indicate that selection is driving the rapid spread of an introduced pathogen population that is more toxigenic and potentially more vigorous. The discovery of this previously unrecognized pathogen diversity has significant implications for food safety and cereal production in North America. [Copyright &y& Elsevier]

Abstract: Phytophthora species are devastating plant pathogens in both agricultural and natural environments. Due to their significant economic and environmental impact, there has been increasing interest in Phytophthora genetics and genomics, culminating in the recent release of three complete genome sequences (P. ramorum, P. sojae, and P. infestans). In this study, genome and other large sequence databases were used to identify over 225 potential genetic markers for phylogenetic analyses. Here, we present a genus-wide phylogeny for 82 Phytophthora species using seven of the most informative loci (approximately 8700 nucleotide sites). Our results support the division of the genus into 10 well-supported clades. The relationships among these clades were rigorously evaluated using a number of phylogenetic methods. This is the most comprehensive study of Phytophthora relationships to date, and many newly discovered species have been included. A more resolved phylogeny of Phytophthora species will allow for better interpretations of the overall evolutionary history of the genus. [Copyright &y& Elsevier]

Abstract: To expand our knowledge of Fusarium head blight (FHB) pathogen and trichothecene toxin diversity, a global collection of 2100 isolates was screened for novel genetic variation, resulting in the identification of 16 phylogenetically divergent FHB isolates. The affinities and taxonomic status of these novel isolates were evaluated via phylogenetic analyses of multilocus DNA sequence data (13 genes; 16.3kb/strain) together with analyses of their morphology, pathogenicity to wheat, and trichothecene toxin potential. Based on the results of these analyses, we formally describe two novel species (Fusarium vorosii and Fusarium gerlachii) within the Fusarium graminearum species complex (Fg complex), and provide the first published report of Fg complex isolates with either a nivalenol or 3-acetyldeoxynivalenol chemotype within the U.S. In addition, we describe a highly divergent population of F. graminearum from the Gulf Coast of the U.S., and divergent isolates of F. acaciae-mearnsii from Australia and South Africa. [Copyright &y& Elsevier]

In colony collapse disorder (CCD), honey bee colonies inexplicably lose their workers. CCD has resulted in a loss of 50 to 90% of colonies in beekeeping operations across the United States. The observation that irradiated combs from affected colonies can be repopulated with naive bees suggests that infection may contribute to (CD. We used an unbiased metagenomic approach to survey microflora in (CD hives, normal hives, and imported royal jelly. Candidate pathogens were screened for significance of association with CCD by the examination of samples collected from several sites over a period of 3 years. One organism, Israeli acute paralysis virus of bees, was strongly correlated with CCD. [ABSTRACT FROM AUTHOR]