The performance of DNA metabarcoding approaches for characterizing biodiversity can be influenced by multiple factors. Here, we used morphological assessment of taxa in zooplankton samples to develop a large barcode database and to assess the congruence of taxonomic identification with metabarcoding under different conditions. We analysed taxonomic assignment of metabarcoded samples using two genetic markers (COI, 18S V1–2), two types of clustering into molecular operational taxonomic units (OTUs, ZOTUs), and three methods for taxonomic assignment (RDP Classifier, BLASTn to GenBank, BLASTn to a local barcode database). The local database includes 1042 COI and 1108 18S (SSU) barcode sequences, and we added new high-quality sequences to GenBank for both markers, including 109 contributions at the species level. The number of phyla detected and the number of taxa identified to phylum varied between a genetic marker and among the three methods used for taxonomic assignments. Blasting the metabarcodes to the local database generated multiple unique contributions to identify OTUs and ZOTUs. We argue that a multi-marker approach combined with taxonomic expertise to develop a curated, vouchered, local barcode database increases taxon detection with metabarcoding, and its potential as a tool for zooplankton biodiversity surveys.

中文翻译：

---

分类学专业知识在解释元条形码研究中的作用

用于表征生物多样性的 DNA 元条形码方法的性能可能受到多种因素的影响。在这里，我们使用浮游动物样本中分类群的形态学评估来开发大型条形码数据库，并评估不同条件下分类识别与元条形码的一致性。我们使用两个遗传标记（COI，18S V1-2）、两种类型的聚类成分子操作分类单位（OTU、ZOTU）和三种分类分配方法（RDP 分类器、BLASTn 到 GenBank、BLASTn到本地条形码数据库）。本地数据库包括 1042 个 COI 和 1108 个 18S (SSU) 条形码序列，我们在 GenBank 中为这两个标记添加了新的高质量序列，包括物种水平的 109 个贡献。检测到的门的数量和鉴定到门的分类群的数量在遗传标记和用于分类学分配的三种方法之间有所不同。将元条形码爆破到本地数据库会产生多个独特的贡献来识别 OTU 和 ZOTU。我们认为，多标记方法与分类学专业知识相结合，开发一个经过策划的、有凭证的本地条形码数据库，通过元条形码增加了分类单元的检测，以及它作为浮游动物生物多样性调查工具的潜力。