Taxonomic reference libraries for environmental barcoding: a best practice example from diatom research

Area of Science:

• Environmental barcoding
• Molecular taxonomy
• Diatom research

Background:

• DNA barcoding relies on high-quality reference databases for accurate taxonomic identification.
• Environmental barcoding requires robust reference libraries for analyzing environmental samples.

Purpose of the Study:

• To create best practice guidelines for taxonomic reference libraries for environmental barcoding.
• To critically examine and combine multiple data types for improved reference library creation.

Main Methods:

• Established and cultured 70 unialgal diatom strains from Berlin waters.
• Sequenced 18S V4 rDNA and rbcL genes for molecular data.
• Performed microscopy (LM, SEM) for morphological identification and deposited physical vouchers.

Main Results:

• Identified 37 freshwater diatom taxa from 15 naviculoid genera.
• Described four new taxa from the genera Amphora, Mayamaea, Planothidium, and Stauroneis.
• Made molecular, morphological, and habitat data publicly available in the AlgaTerra Information System.

Conclusions:

• Linked all reference sequences to voucher specimens for a complete chain of evidence.
• Provided a model for creating high-quality, data-rich reference libraries for environmental barcoding.
• Emphasized the importance of integrating morphological and molecular data for taxonomic validation.