MOLECULAR PHYLOGENY AND TAXONOMIC REVISION OF FUNGI IN THE GENUS Thelonectria AND RELATED SPECIES WITH Cylindrocarpon-LIKE ANAMORPHS

The genus Thelonectria and related species with Cylindrocarpon-like anamorphs are a group of perithecial ascomycetes in the family Nectriaceae that occur as saprobes and in few cases as pathogens of hardwood trees, shrubs or other plant substrates. Despite of being a key component of forest ecosystems around the world, species relationships and distribution are largely unknown. The objectives of this study were to: 1) infer species level phylogenetic relationships of the genus Thelonectria and related species with Cylindrocarpon-like anamorphs with uncertain classification, testing monophyly of each one of the groups studied; 2) delimit taxa, establishing taxon circumscriptions and providing brief descriptions; 3) resolve nomenclatural issues by identifying redundantly used names and synonyms; 4) provide identification tools, specifically, diagnostic keys and molecular data that can be used further as molecular barcodes; 4) provide distribution data and to take the first steps into the identification of speciation patterns observed in these fungi. To achieve these goals, herbarium materials, as well as freshly collected material obtained from the field or from fungal repositories were compared using phylogenetic analyses of multiple loci, morphology and geographic distribution. This research resulted in the narrower circumscription of the genus Thelonectria, not to contain one of the most common species in the group, T. jungneri. According to the results of the phylogenetic analyses it was found T. jungneri is a segregating clade that needs to be recognized as a different genus. For the genus Thelonectria, a total of 31 new species were described, and three new genera, closely related to Thelonectria were created to accommodate the diversity of other species with Cylindrocarpon-like anamorphs: Cinnamonectria gen nov. with C. cinnamomea as type taxon, Macronectria gen. nov. with M. jungneri as type taxon, and Tumenectria gen. nov. with T. laetidisca as type taxon. Species in this group of fungi present extensive morphological conservationism, representing a challenge for species identification without the use of molecular techniques, however offering a great opportunity to explore mechanisms of speciation and evolutionary diversification

Not as Ubiquitous as We Thought: Taxonomic Crypsis, Hidden Diversity and Cryptic Speciation in the Cosmopolitan Fungus Thelonectria discophora (Nectriaceae, Hypocreales, Ascomycota)

Funding for Open Access provided by the UMD Libraries Open Access Publishing Fund.The distribution of microbial species, including fungi, has long been considered cosmopolitan. Recently, this perception has been challenged by molecular studies in historical biogeography, phylogeny and population genetics. Here we explore this issue using the fungal morphological species Thelonectria discophora, one of the most common species of fungi in the family Nectriaceae, encountered in almost all geographic regions and considered as a cosmopolitan taxon. In order to determine if T. discophora is a single cosmopolitan species or an assemblage of sibling species, we conducted various phylogenetic analyses, including standard gene concatenation, Bayesian concordance methods, and coalescent-based species tree reconstruction on isolates collected from a wide geographic range. Results show that diversity among isolates referred as T. discophora is greatly underestimated and that it represents a species complex. Within this complex, sixteen distinct highly supported lineages were recovered, each of which has a restricted geographic distribution and ecology. The taxonomic status of isolates regarded as T. discophora is reconsidered, and the assumed cosmopolitan distribution of this species is rejected. We discuss how assumptions about geographically widespread species have implications regarding their taxonomy, true diversity, biological diversity conservation, and ecological functions.This study was funded by a grant from United States National Science Foundation (PEET program, grant number DEB-0925696: “Monographic Studies in the Nectriaceae, Hypocreales: Nectria, Cosmospora, and Neonectria” http://www.nsf.gov/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Genome analysis of the ubiquitous boxwood pathogen Pseudonectria foliicola

Boxwood (Buxus spp.) are broad-leaved, evergreen landscape plants valued for their longevity and ornamental qualities. Volutella leaf and stem blight, caused by the ascomycete fungi Pseudonectria foliicola and P. buxi, is one of the major diseases affecting the health and ornamental qualities of boxwood. Although this disease is less severe than boxwood blight caused by Calonectria pseudonaviculata and C. henricotiae, its widespread occurrence and disfiguring symptoms have caused substantial economic losses to the ornamental industry. In this study, we sequenced the genome of P. foliicola isolate ATCC13545 using Illumina technology and compared it to other publicly available fungal pathogen genomes to better understand the biology of this organism. A de novo assembly estimated the genome size of P. foliicola at 28.7 Mb (425 contigs; N50 = 184,987 bp; avg. coverage 188×), with just 9,272 protein-coding genes. To our knowledge, P. foliicola has the smallest known genome within the Nectriaceae. Consistent with the small size of the genome, the secretome, CAzyme and secondary metabolite profiles of this fungus are reduced relative to two other surveyed Nectriaceae fungal genomes: Dactylonectria macrodidyma JAC15-245 and Fusarium graminearum Ph-1. Interestingly, a large cohort of genes associated with reduced virulence and loss of pathogenicity was identified from the P. foliicola dataset. These data are consistent with the latest observations by plant pathologists that P. buxi and most likely P. foliicola, are opportunistic, latent pathogens that prey upon weak and stressed boxwood plants

Fusarium and allied fusarioid taxa (FUSA). 1

Seven Fusarium species complexes are treated, namely F. aywerte species complex (FASC) (two species), F. buharicum species complex (FBSC) (five species), F. burgessii species complex (FBURSC) (three species), F. camptoceras species complex (FCAMSC) (three species), F. chlamydosporum species complex (FCSC) (eight species), F. citricola species complex (FCCSC) (five species) and the F. concolor species complex (FCOSC) (four species). New species include Fusicolla elongata from soil (Zimbabwe), and Neocosmospora geoasparagicola from soil associated with Asparagus officinalis (Netherlands). New combinations include Neocosmospora akasia, N. awan, N. drepaniformis, N. duplosperma, N. geoasparagicola, N. mekan, N. papillata, N. variasi and N. warna. Newly validated taxa include Longinectria gen. nov., L. lagenoides, L. verticilliforme, Fusicolla gigas and Fusicolla guangxiensis. Furthermore, Fusarium rosicola is reduced to synonymy under N. brevis. Finally, the genome assemblies of Fusarium secorum (CBS 175.32), Microcera coccophila (CBS 310.34), Rectifusarium robinianum (CBS 430.91), Rugonectria rugulosa (CBS 126565), and Thelonectria blattea (CBS 952.68) are also announced her

Fusarium: more than a node or a foot-shaped basal cell

Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family Nectriaceae. Thus, an alternate hypothesis, namely a very broad concept of the genus Fusarium was proposed. In doing so, however, a significant body of data that supports distinct genera in Nectriaceae based on morphology, biology, and phylogeny is disregarded. A DNA phylogeny based on 19 orthologous protein-coding genes was presented to support a very broad concept of Fusarium at the F1 node in Nectriaceae. Here, we demonstrate that re-analyses of this dataset show that all 19 genes support the F3 node that represents Fusarium sensu stricto as defined by F. sambucinum (sexual morph synonym Gibberella pulicaris). The backbone of the phylogeny is resolved by the concatenated alignment, but only six of the 19 genes fully support the F1 node, representing the broad circumscription of Fusarium. Furthermore, a re-analysis of the concatenated dataset revealed alternate topologies in different phylogenetic algorithms, highlighting the deep divergence and unresolved placement of various Nectriaceae lineages proposed as members of Fusarium. Species of Fusarium s. str. are characterised by Gibberella sexual morphs, asexual morphs with thin- or thick-walled macroconidia that have variously shaped apical and basal cells, and trichothecene mycotoxin production, which separates them from other fusarioid genera. Here we show that the Wollenweber concept of Fusarium presently accounts for 20 segregate genera with clear-cut synapomorphic traits, and that fusarioid macroconidia represent a character that has been gained or lost multiple times throughout Nectriaceae. Thus, the very broad circumscription of Fusarium is blurry and without apparent synapomorphies, and does not include all genera with fusarium-like macroconidia, which are spread throughout Nectriaceae (e.g., Cosmosporella, Macroconia, Microcera). In this study four new genera are introduced, along with 18 new species and 16 new combinations. These names convey information about relationships, morphology, and ecological preference that would otherwise be lost in a broader definition of Fusarium. To assist users to correctly identify fusarioid genera and species, we introduce a new online identification database, Fusarioid-ID, accessible at www.fusarium.org. The database comprises partial sequences from multiple genes commonly used to identify fusarioid taxa (act1, CaM, his3, rpb1, rpb2, tef1, tub2, ITS, and LSU). In this paper, we also present a nomenclator of names that have been introduced in Fusarium up to January 2021 as well as their current status, types, and diagnostic DNA barcode data. In this study, researchers from 46 countries, representing taxonomists, plant pathologists, medical mycologists, quarantine officials, regulatory agencies, and students, strongly support the application and use of a more precisely delimited Fusarium (= Gibberella) concept to accommodate taxa from the robust monophyletic node F3 on the basis of a well-defined and unique combination of morphological and biochemical features. This F3 node includes, among others, species of the F. fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes, but not species of Bisifusarium [F. dimerum species complex (SC)], Cyanonectria (F. buxicola SC), Geejayessia (F. staphyleae SC), Neocosmospora (F. solani SC) or Rectifusarium (F. ventricosum SC). The present study represents the first step to generating a new online monograph of Fusarium and allied fusarioid genera (www.fusarium.org)

Hongos endofitos en rosa hybrida - aislamiento, identificación y evaluación in vitro de la capacidad antagonica contra hongos fitopatógenos

Magíster en Ciencias BiológicasMaestrí

Data from: Not as ubiquitous as we thought: taxonomic crypsis, hidden diversity and cryptic speciation in the cosmopolitan fungus Thelonectria discophora (Nectriaceae, Hypocreales, Ascomycota)

The distribution of microbial species, including fungi, has long been considered cosmopolitan. Recently, this perception has been challenged by molecular studies in historical biogeography, phylogeny and population genetics. Here we explore this issue using the fungal morphological species Thelonectria discophora, one of the most common species of fungi in the family Nectriaceae, encountered in almost all geographic regions and considered as a cosmopolitan taxon. In order to determine if T. discophora is a single cosmopolitan species or an assemblage of sibling species, we conducted various phylogenetic analyses, including standard gene concatenation, Bayesian concordance methods, and coalescent-based species tree reconstruction on isolates collected from a wide geographic range. Results show that diversity among isolates referred as T. discophora is greatly underestimated and that it represents a species complex. Within this complex, sixteen distinct highly supported lineages were recovered, each of which has a restricted geographic distribution and ecology. The taxonomic status of isolates regarded as T. discophora is reconsidered, and the assumed cosmopolitan distribution of this species is rejected. We discuss how assumptions about geographically widespread species have implications regarding their taxonomy, true diversity, biological diversity conservation, and ecological functions

The human fungal pathogen Paracoccidioides brasiliensis (Onygenales: Ajellomycetaceae) is a complex of two species: Phylogenetic evidence from five mitochondrial markers

Paracoccidioides brasiliensis is the aetiological agent of paracoccidioidomycosis, the most important systemic mycosis in Latin America. In order to study the diversity of P. brasiliensis mitochondrial genes, to evaluate previous taxonomic proposals, and to explore the hypothesis that the previously described "divergent isolate" B30 (also called Pb01) could represent a new P. brasiliensis species, we undertook a molecular phylogenetic analysis based on five mitochondrial markers. Mitochondrial sequences of 59 P. brasiliensis isolates obtained from clinical and environmental samples, and the orthologous genes from outgroup species, are reported and analysed using parsimony and Bayesian methods. The combined data set comprised 2364 characters, of which 426 were informative. One of the studied strains presented a 376-nt insertion at the apocytochrome b (cob) gene. The corresponding sequence had a high similarity (79%) with an intron found in the Neurospora crassa cob gene. Interestingly, this intron is absent in the previously published sequence of the P. brasiliensis mitochondrial genome. Our trees were moderately congruent with the previous P. brasiliensis taxonomic proposals. Furthermore, we identified a new monophyletic group of strains within P. brasiliensis. Nevertheless, the phylogenetic species recognition (PSR) analyses described here suggested that these groups of strains could represent geographical variants rather than different Paracoccidioides cryptic species. In addition, and as previously proposed by other authors, these analyses supported the existence of a new specie of Paracoccidioides, which includes the previously described, divergent isolate B30/Pb01. This is the first report providing evidence, independent of nuclear markers, for the split of this important human pathogen into two species. We support the formal description of the B30/Pb01 as new specie.Fil: Salgado Salazar, Catalina. Universidad de Antioquia; Colombia. Corporación Para Investigaciones Biológicas; ColombiaFil: Jones, Leandro Roberto. Fundación Playa Unión. Estación de Fotobiología Playa Unión; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Restrepo, Ángela. Corporación Para Investigaciones Biológicas; ColombiaFil: McEwen, Juan G.. Universidad de Antioquia; Colombia. Corporación Para Investigaciones Biológicas; Colombi

Nucleotide divergence (Dxy^*) for all pairwise comparisons of putative species identified within <i>T. discophora</i> species-complex.

*<p><i>p</i><0.001.</p><p>All positions containing gaps were eliminated for a total of 3708 positions. Numbers across the top row correspond to putative species numbers in the first column.</p

Polymorphism statistic for putative species within the <i>T. discophora</i> species-complex.

<p>N, number of sequences/individuals, Npoly, number of polymorphic sites, h, number of unique haplotypes, π, nucleotide diversity.</p