Comment on Acquiring DNA sequence data from dried archival red algae (Florideophyceae) for the purpose of applying available names to contemporary genetic species: a critical assessment

Saunders and McDevit recently reported their efforts to extract and amplify DNA by PCR in successively older red algal (Rhodophyta) herbarium specimens. They found that recent collections (4-11 years old) readily amplified but that archival material (decades to a century old) yielded contamination problems, diminished success correlated with age, or failed to amplify. As a solution, they proposed that epitypes be designated based on contemporary sequenced specimens. In response, we extracted and amplified in independent laboratories three loci (COI, ITS2, and rbcL) from the same 1836 Sparlingia pertusa specimen that Saunders and McDevit were unable to amplify. The use of Q-solution enhanced amplification success and likely is partly responsible for our achievements with archival specimens. These findings, along with data from the last 13 years in which we have sequenced over 100 historical and type specimens, indicate that with proper controls, amplifying DNA from red algal herbarium specimens of any age is practical and reproducible. The designation of contemporary epitypes should be a last resort, not an alternative to sequencing type material, and must be done with an understanding of the historical record of the species.