Using Barcode Similarity Groups to Organize Cortinarius Sequences

To improve fungal identification using a single DNA sequence, I introduce the Barcode Similarity Group (BSG) defined as a cluster of sequences that share greater than or equal to a threshold amount of genetic similarity with each other. As a test case, I created 393 BSGs from 2463 Cortinarius ITS sequences using a 94% similarity cut-off value in DOTUR. Some BSGs may contain multiple species. The BSG database was used to label environmental sequences, find misidentified or mislabeled sequences, and find potential cryptic species and novel species. Expert taxonomists will be needed to perform detailed morphological and phylogenetic studies to identify the individual species within each BSG. The main advantage of using BSGs is that it clusters together sequences using total genetic relatedness and does not rely on any taxonomy for identification. A website was created where the RDP Classifier is used to classify a query sequence into a BSG.MAS