DNA barcoding for identification of species in mushrooms: A component of product certification

One challenge in the botanical industry is the confirmation of species identification, and this can be compounded by the processing of the materials before reaching the vendor, such as milling or drying. This can be particularly difficult for samples that contain fungal mycelia, where morphological characteristics do not present sufficient variation to differentiate species. However, monitoring the safety and quality of such products is a requirement for the protection of consumer health. DNA barcoding, a genetic-based species identification system, has become popular in the past decade, and it shows great promise for species level identification of fungi. By using DNA barcoding of nuclear ribosomal internal transcribed spacer (ITS) of the rRNA gene with fungal specific ITS primers, we generated ITS barcodes for two representative mushroom fungi, which are being used by consumers for food and dietary supplement purposes. After generating ITS barcodes utilizing standard procedures accepted by the Consortium for the Barcode of Life, we tested the utility of the ITS by performing a BLAST search against both curated and non-curated public databases. Results demonstrated that the ITS region was able to identify both mushrooms used in the present study to species-level. The BLAST search provided 99% similarity of the query sequence to those available in the public database. We anticipate that this presentation will motivate a discussion on DNA barcoding based species identification, particularly as it applies to the verification/certification of mushrooms containing products.