DNA barcoding evaluation of geophytes: Comparative efficiency of three barcode loci for Anemone (Ranunculaceae) and Gladiolus (Iridaceae)

Anemone and Gladiolus are economically important geophyte genera due to their usage as ornamental plants. However, species identification is still under debate. Recently, DNA barcoding has become an efficient alternative tool for species identification. Here, candidate DNA barcode regions, rbcL, rpoB, and trnH-psbA were analyzed as potential DNA barcodes in 248 accessions of these geophyte genera using pair-wise distance-based, sequence similarity (best match and best close match) and tree-based (neighbor joining, maximum likelihood, and Bayesian tree) methods. Among all barcoding single or combination loci, trnH-psbA had the highest interspecific genetic variation in Anemone, and the region was the most promising candidate for barcoding gap analysis. However, none of the barcode regions showed a clear barcode gap for identification. The internal spacer, trnH-psbA, also showed the highest correct identification rate in Anemone, while rbcL showed the best performance in Gladiolus using the sequence similarity method. In the single barcode approach, rpoB had the best discrimination rate for both genera when using tree-based methods. Therefore, we recommend a tree-based method because it was clear that all tested loci had specific performance degrees depending on the methods. This is the first application of rpoB in terms of DNA barcoding criteria in geophyte taxa. Supplemental data for this article is available online at .