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Phylogenetic distribution of alpha-amanitin producing Galerina of British Columbia

University of British Columbia

Mushrooms of some Galerina species equal the most poisonous Amanita species in their concentrations of deadly amanitin toxins. Although individual Galerina mushrooms are small, eating about ten would risk delivering a lethal dose of amanitins to a child. Understanding which species of Galerina pose an acute poisoning risk requires a better understanding of species boundaries within the genus, as well broad sampling for the presence of amatoxins. I analyzed 61 Galerina and eight outgroup specimens for the presence of amatoxins using HPLC/LC-MS. I then used multi-locus DNA data (ITS, LSU and RPB2) from a broad sampling of Galerina and outgroup taxa to generate a constraint tree, to which 322 Galerina ITS sequences from herbarium specimens at UBC, from A.H. Smith’s type material (University of Michigan) and from Genbank were added. I mapped toxin analysis data onto the resulting phylogeny, which indicated that amatoxin-production in BC Galerina is restricted to two species, G. venenata and G. castaneipes. These two species, along with two other reportedly toxic species (G. aff. marginata and G. sulciceps) and seven other species whose toxin production status remains unknown form a broad clade referred to as the G. marginata complex. Phylogenetic and toxin data suggest that the sister clade to the G. marginata complex (G. badipes) does not produce toxins, implying that the origin of amatoxin production in Galerina is somewhere within the G. marginata complex. Additionally, phylogenetic data also supports past evidence that members of the genus Gymnopilus are nested within the ‘Mycenopsis’ lineage of Galerina. The results provide the first comprehensive look at toxin production in Galerina, as well as the first report of additional toxin-producing species in North America. Using the molecular data from this study to update specimen names in herbarium collections and online databases will reduce downstream confusion resulting from inaccurate identifications or misapplied names. Doing so will contribute to ongoing efforts to update of field guides and other resources that list poisonous and edible mushrooms, allowing amateur mycologists, foragers and healthcare professionals to gain a better understanding of which Galerina pose a poisoning risk.

Text

2019-05-09

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/70134

Botany

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/