A tufA metabarcoding approach for Ulva and related seaweeds

Ulva -like green algae are notoriously difficult to distinguish due their morphological variability and/or similarity. DNA barcoding approaches therefore currently essential for reliable identification. However, such often fail when rare or inconspicuous species be detected in large mixed populations of species, example, at early stages following the introduction into new habitats. We developed a detection method based on next-generation sequencing. The approach is suitable analysis traces preserved water samples particles enriched by filtration from samples. A pair primers was designed amplify 475 bp segment within tufA marker gene. were relatively group specific. 68.5% all reads obtained after quality filtering represented genus Ulva, 11.1% other Ulvophyceae, and only 20% Chlorophyta, despite higher abundance phytoplankton. short target amplicon still allows good differentiation Ulvales Ulothrichales level. Using database containing sequences 879 - 281 which Ulvophyceae 35 we able detect mostly that had been previously our study area northern Germany using Sanger number individual sites generally than previous studies, could drifting DNA: Analysis collected different distances shore suggests sample given site may influenced radius up about 1 km winter. In summer, this reduced less 100 m, possibly frequent occurrence strong wind events. Nonetheless, with approach: At one site, an undescribed Blidingia not known repeatedly detected. Based these findings, searched found, its identity confirmed traditional barcoding.