Determining threshold values for barcoding fungi: lessons from Cortinarius (Basidiomycota), a highly diverse and widespread ectomycorrhizal genus

Sigisfredo Garnica, Max Emil Schön, Kessy Abarenkov, Kai Riess, Kare Liimatainen, Tuula Niskanen, Bálint Dima, Karl Soop, Tobias Guldberg Frøslev, Thomas Stjernegaard Jeppesen, Ursula Peintner, Regina Kuhnert-Finkernagel, Tor Erik Brandrud, Günter Saar, Bernhard Oertel, Joseph F. Ammirati

    60 Citationer (Scopus)

    Abstract

    Different distance-based threshold selection approaches were used to assess and compare use of the internal transcribed spacer (ITS) region to distinguish among 901 Cortinarius species represented by > 3000 collections. Sources of error associated with genetic markers and selection approaches were explored and evaluated using MOTUs from genus and lineage based-alignments. Our study indicates that 1%-2% more species can be distinguished by using the full-length ITS barcode as compared to either the ITS1 or ITS2 regions alone. Optimal threshold values for different picking approaches and genetic marker lengths inferred from a subset of species containing major lineages ranged from 97.0% to 99.5% sequence similarity using clustering optimization and UNITE SH, and from 1% to 2% sequence dissimilarity with CROP. Errors for the optimal cutoff ranged from 0% to 70%, and these can be reduced to a maximum of 22% when excluding species lacking a barcode gap. A threshold value of 99% is suitable for distinguishing species in the majority of lineages in the genus using the entire ITS region but only 90% of the species could be identified using just the ITS1 or ITS2 region. Prior identification of species, lacking barcode gaps and their subsequent separate analyses, maximized the accuracy of threshold approaches.

    OriginalsprogEngelsk
    Artikelnummerfiw045
    TidsskriftFEMS Microbiology Ecology
    Vol/bind92
    Udgave nummer4
    Antal sider16
    ISSN0168-6496
    DOI
    StatusUdgivet - apr. 2016

    Fingeraftryk

    Dyk ned i forskningsemnerne om 'Determining threshold values for barcoding fungi: lessons from Cortinarius (Basidiomycota), a highly diverse and widespread ectomycorrhizal genus'. Sammen danner de et unikt fingeraftryk.

    Citationsformater