title: Phylogeny and variability of Colletotrichum truncatum associated with soybean anthracnose in Brazil.
abstract: OBJECTIVE
  Fungal diseases are among the main factors limiting high yields of soybean crop. Colletotrichum isolates from soybean plants with anthracnose symptoms were studied from different regions and time periods in Brazil using molecular, morphological and pathogenic analyses.
  
  
  RESULTS
  Bayesian phylogenetic inference of GAPDH, HIS3 and ITS-5.8S rDNA sequences, the morphologies of colony and conidia, and inoculation tests on seeds and seedlings were performed. All isolates clustered only with Colletotrichum truncatum species in three well-separated clusters. Intraspecific genetic diversity revealed 27 distinct haplotypes in 51 fungal isolates; some of which were identical to C. truncatum sequences from other regions around the world, while others were related to alternative hosts. Conidia were falcate, hyaline, unicellular and aseptate, formed in acervuli, with variable dimensions. Despite being pathogenic to seedlings by both inoculation methods, variation was observed in the aggressiveness of the tested isolates, which was not correlated with genetic variation.
  
  
  CONCLUSIONS
  The identification of C. truncatum in the sampled isolates was evidenced as being the only causal agent of soybean anthracnose in Brazil until 2007, with relevant genetic, morphological and pathogenic variability as well as a broad geographical origin. The wide distribution of the predominant C. truncatum haplotype indicated the existence of a highly efficient mechanism of pathogen dispersal over long distances, reinforcing the role of seeds as the primary source of disease inoculum.
  
  
  CONCLUSIONS
  The characterization and distribution of Colletotrichum species in soybean-producing regions in Brazil is fundamental for understanding the disease epidemiology and for ensuring effective control strategies against anthracnose.
authors.affiliation: Departamento de Fitopatologia e Nematologia (ESALQ/USP), Universidade de São Paulo, Piracicaba, São Paulo, Brazil.
authors.forename: F
authors.initials: F
authors.lastname: Rogério
authors.affiliation: Departamento de Fitopatologia e Nematologia (ESALQ/USP), Universidade de São Paulo, Piracicaba, São Paulo, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Ciampi-Guillardi
authors.affiliation: Departamento de Fitopatologia e Nematologia (ESALQ/USP), Universidade de São Paulo, Piracicaba, São Paulo, Brazil.
authors.forename: M C G
authors.initials: MC
authors.lastname: Barbieri
authors.affiliation: Universidade Federal do Recôncavo da Bahia (UFRB), Cruz das Almas, Bahia, Brazil.
authors.forename: C A D
authors.initials: CA
authors.lastname: Bragança
authors.affiliation: Embrapa Soja, Londrina, Paraná, Brazil.
authors.forename: C D S
authors.initials: CD
authors.lastname: Seixas
authors.affiliation: Embrapa Soja, Londrina, Paraná, Brazil.
authors.forename: A M R
authors.initials: AM
authors.lastname: Almeida
authors.affiliation: Departamento de Fitopatologia e Nematologia (ESALQ/USP), Universidade de São Paulo, Piracicaba, São Paulo, Brazil.
authors.forename: N S
authors.initials: NS
authors.lastname: Massola
mesh_terms: D001499:Bayes Theorem; D001938:Brazil; D020231:Colletotrichum / Q000145:classification / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification*; D004271:DNA, Fungal / Q000235:genetics; D004275:DNA, Ribosomal; D014644:Genetic Variation; D005843:Geography; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D013025:Glycine max / Q000235:genetics / Q000382:microbiology*; D013172:Spores, Fungal / Q000145:classification / Q000166:cytology / Q000302:isolation & purification
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal
keywords: fungi; genetic diversity; microbial phylogenetics; multilocus; plant disease