title: Polyphasic analysis of intraspecific diversity in Epicoccum nigrum warrants reclassification into separate species.
abstract: BACKGROUND
  Epicoccum nigrum Link (syn. E. purpurascens Ehrenb. ex Schlecht) is a saprophytic ascomycete distributed worldwide which colonizes a myriad of substrates. This fungus has been known as a biological control agent for plant pathogens and produces a variety of secondary metabolites with important biological activities as well as biotechnological application. E. nigrum produces darkly pigmented muriform conidia on short conidiophores on sporodochia and is a genotypically and phenotypically highly variable species. Since different isolates identified as E. nigrum have been evaluated as biological control agents and used for biocompound production, it is highly desirable that this species name refers to only one lineage. However, according to morphological and genetic variation, E. nigrum present two genotypes that may comprise more than one species.
  
  
  RESULTS
  We report the application of combined molecular (ITS and β-tubulin gene sequence analysis, PCR-RFLP and AFLP techniques), morphometric, physiological, genetic compatibility and recombination analysis to study the taxonomic relationships within an endophytic population that has been identified as E. nigrum. This combined analysis established two genotypes showing morphological, physiological and genetic divergence as well as genetic incompatibility characterized by colony inhibition, strongly indicating that these genotypes correspond to different species. Genotype 1 corresponds to E. nigrum while genotype 2 represents a new species, referred to in this study as Epicoccum sp.
  
  
  CONCLUSIONS
  This research contributes to the knowledge of the Epicoccum genus and asserts that the classification of E. nigrum as a single variable species should be reassessed. In fact, based on the polyphasic approach we suggest the occurrence of cryptic species within E. nigrum and also that many of the sequences deposited as E. nigrum in GenBank and culture collection of microbial strains should be reclassified, including the reference strain CBS 161.73 sequenced in this work. In addition, this study provides valuable tools for differentiation of Epicoccum species.
authors.affiliation: Empraba Agroenergia, Brazilian Agricultural Research Corporation, Brasília, Distrito Federal, Brazil.
authors.forename: Léia Cecilia de Lima
authors.initials: LC
authors.lastname: Fávaro
authors.forename: Fernando Lucas
authors.initials: FL
authors.lastname: de Melo
authors.forename: Carlos Ivan
authors.initials: CI
authors.lastname: Aguilar-Vildoso
authors.forename: Welington Luiz
authors.initials: WL
authors.lastname: Araújo
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D001203:Ascomycota / Q000145:classification* / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D001483:Base Sequence; D001499:Bayes Theorem; D015169:Colony Count, Microbial; D016172:DNA Fingerprinting; D021901:DNA, Intergenic / Q000235:genetics; D005656:Fungal Proteins / Q000378:metabolism; D014644:Genetic Variation; D050505:Mutant Proteins / Q000302:isolation & purification / Q000378:metabolism; D025282:Mycelium / Q000378:metabolism; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011995:Recombination, Genetic / Q000235:genetics; D013045:Species Specificity; D013172:Spores, Fungal / Q000166:cytology; D014404:Tubulin / Q000235:genetics
chemical_list: D021901:DNA, Intergenic; D005656:Fungal Proteins; D050505:Mutant Proteins; D014404:Tubulin