Habitat and host indicate lineage identity in Colletotrichum gloeosporioides s.l. from wild and agricultural landscapes in North America

PLoS One. 2013 May 6;8(5):e62394. doi: 10.1371/journal.pone.0062394. Print 2013.

Abstract

Understanding the factors that drive the evolution of pathogenic fungi is central to revealing the mechanisms of virulence and host preference, as well as developing effective disease control measures. Prerequisite to these pursuits is the accurate delimitation of species boundaries. Colletotrichum gloeosporioides s.l. is a species complex of plant pathogens and endophytic fungi for which reliable species recognition has only recently become possible through a multi-locus phylogenetic approach. By adopting an intensive regional sampling strategy encompassing multiple hosts within and beyond agricultural zones associated with cranberry (Vaccinium macrocarpon Aiton), we have integrated North America strains of Colletotrichum gloeosporioides s.l. from these habitats into a broader phylogenetic framework. We delimit species on the basis of genealogical concordance phylogenetic species recognition (GCPSR) and quantitatively assess the monophyly of delimited species at each of four nuclear loci and in the combined data set with the genealogical sorting index (gsi). Our analysis resolved two principal lineages within the species complex. Strains isolated from cranberry and sympatric host plants are distributed across both of these lineages and belong to seven distinct species or terminal clades. Strains isolated from V. macrocarpon in commercial cranberry beds belong to four species, three of which are described here as new. Another species, C. rhexiae Ellis & Everh., is epitypified. Intensive regional sampling has revealed a combination of factors, including the host species from which a strain has been isolated, the host organ of origin, and the habitat of the host species, as useful indicators of species identity in the sampled regions. We have identified three broadly distributed temperate species, C. fructivorum, C. rhexiae, and C. nupharicola, that could be useful for understanding the microevolutionary forces that may lead to species divergence in this important complex of endophytes and plant pathogens.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Agriculture
  • Bayes Theorem
  • Colletotrichum / classification*
  • Colletotrichum / genetics*
  • Colletotrichum / growth & development
  • Ecosystem
  • Genes, Fungal
  • Likelihood Functions
  • Multilocus Sequence Typing
  • Mycological Typing Techniques
  • Phylogeny
  • Plant Diseases / microbiology
  • Plant Stems / microbiology
  • United States
  • Vaccinium macrocarpon / microbiology

Grants and funding

Financial support from the National Science Foundation [www.nsf.gov] (DBI 0749751 and DEB 1011120 - Doctoral Dissertation Improvement Grant), the Torrey Botanical Society Graduate Research Fellowship [www.torreybotanical.org], and The New York Botanical Garden [www.nybg.org] helped to fund this research. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.