Identification of the Plant Family Caryophyllaceae in Korea Using DNA Barcoding

Caryophyllaceae is a large angiosperm family, with many species being utilized as ornamental or medicinal plants in Korea, in addition to several endangered species that are managed by the government. In this study, we used DNA barcoding for the accurate identification of Korean Caryophyllaceae. A total of 78 taxa (n = 215) were sequenced based on three chloroplast regions (rbcL, matK, and psbA–trnH) and nuclear ribosomal internal transcribed spacers (ITS). In the neighbor-joining tree, a higher accuracy of identification was generally observed when using ITS (>73%) rather than chloroplast regions (<62%). The highest resolution was found for rbcL + ITS (77.6%), although resolution varied according to the genus. Among the genera that included two and more species, five genera (Eremogone, Minuartia, Pseudostellaria, Sagina, and Stellaria) were successfully identified. However, the species of five other genera (Cerastium, Gypsophila, Dianthus, Silene, and Spergularia) showed relatively low resolutions (0–61.1%). In the cases of Cerastium, Dianthus, and Silene, ambiguous taxonomic relationships among unidentified species may have been a factor contributing to such low resolutions. However, in contrast to these results, Gypsophila and Spergularia have been identified well in previous studies. Our findings indicate the need of taxonomic reconsideration in Korea.