The UNITE database for molecular identification of fungi - recent updates and future perspectives

Ectomycorrhizal (ECM) fungi are typically examined for taxonomic affiliation through sequence similarity searches involving the internal transcribed spacer (ITS) region of the nuclear ribosomal repeat unit and the International Nucleotide Sequence Databases (INSD) (Peay et al., 2008; Taylor, 2008; Benson et al., 2009; Tedersoo et al., 2010). However, the usefulness of these searches is constrained by the technical quality and the taxonomic reliability of the reference sequences in the databases (Nilsson et al., 2006; Bidartondo, 2008). The meagre data on voucher specimen, country of collection and host, which are associated with many of the entries, place a further restriction on the usefulness of the entries in an ecological or taxonomic context (Ryberg et al., 2009). The UNITE project (Kõljalg et al., 2005) was initiated in 2001 to address these problems through a free online database for high-quality reference records of ITS sequences from North European ECM fungi. Taxonomic reliability was the founding principle of the initiative; all records were determined to species level (or as far as possible) by researchers well versed in the taxonomic group in question, and all sequences were obtained from, or in association with, richly annotated fruiting bodies (voucher specimens) deposited in public herbaria.