DNA barcoding of Boletales collections hosted in the Biodiversity Centre Fungarium

par Stefani, F.O.P., Megarbané, L., Lebeuf, R., Lamoureux, Y. et Archambault, R.


The Biodiversity Centre Fungarium hosts 406 collections of Boletales from Quebec, representing 30 genera and 131 species, identified by morphological characters. Thanks to financial support from the Cercle des mycologues de Montréal, DNA barcoding of these collections was undertaken. Total genomic DNA was isolated from the 406 collections and ITS 1 and 2 were amplified. Positive amplifications were obtained for 338 collections (83%) while clean ITS sequences were obtained for 251 collections (62%). Using a similarity threshold of 98%, the 251 ITS sequences clustered into 116 OTUs. About half of the collections were correctly identified, i.e. the collection names from the morphological identification were congruent with the names recovered from querying the GenBank public database with the ITS sequences. A quarter of the collections were misidentified and another quarter of the taxa had no representatives in GenBank. The taxonomic identification based on the ITS sequence analysis showed that the Boletales collections are mostly dominated by the genera Boletus (34%), Suillus (14%) and Leccinum (9%). The analysis of the rarefaction curve showed that Boletales diversity was not saturated. Results from this DNA barcoding project show the importance of systematic DNA sequencing from fungarium collections for curating misidentified collections, for building better reference databases, and for discovering yet undescribed fongal species.