DNA Barcording Projects of the Native Vascular Plants in Korea
LIM Chae Eun National Institute of Biological Resources, Incheon 22689, Korea
Building a DNA barcode database at the local scale is crucial for conservation biology and practical use of biological resources in many areas such as agriculture, pharmaceutical. Recently, misuses, mixed uses, forges, and falsifications of biological materials have been rapidly growing due to challenges of identification. Since 2008, National Institute of Biological Resources (NIBR) has established a DNA barcode database of Korean vascular plants for the following purposes: (1) to discover cryptic species; (2) to discriminate morphologically indistinguishable taxa for securing food safety and the authenticity of plant derived biomaterials and (3) to provide solid taxonomic information on ecological, evolutionary and environmental studies.
I. Genus-level reference library of Korean vascular plants
We examined the rbcL sequences of all plant genera in Korea (1,122 genera) and constructed the Genus-Level Reference Library for Korean vascular plants. Neighbor-joining analysis of 1,122 Korean vascular plants on the rbcL library revealed a high resolution of genus-level taxonomic relationship (>95%). Additionally, we built a barcode reference library containing with three more markers, matK, psbA-trnH, and ITS for 2,795 (62% of 4,518 species listed in the Database of vascular plants in Korea).
II. Discovery of cryptic species in Korea
Halenia coreana S.M. Han, H. Won & C.E. Lim, sp. nov. is supported by recent DNA barcoding analyses that utilized multiple accessions from several populations of the taxa examined (Han et al., 2019). Within the ITS tree, the seven accessions representing the new species formed a distinct clade with a high bootstrap value (99%).
III. Molecular diagnosis of problematic taxa for securing food safety
Formally, the conventional DNA barcodes ambiguously and/or falsely discriminated plant materials with low resolution e.g. Genus Artemisia. For those problematic taxa, we applied (1) DNA barcoding, (2) Chloroplast genome sequencing, and (3) Target-enrichment sequencing (Hyb-Seq) to develop molecular markers that can distinguish each species of Artemisia. A maximum-likelihood inference with the newly developed markers from Hyb-Seq analysis exhibited significantly high resolution (100%) at species level in Korean Artemisia.
Our results suggested that barcode reference library is more effective for taxonomic problems in a genus level. For the species level, we found that identification markers collected across multiple genes through Hyb-Seq technique improve the resolution significantly. The barcode markers we developed may well be practically applied to discriminate traditional medicinal herbs in Korea such as Artemisia species.
Han, S.-M., Won, H., & Lim C.E. 2019. Halenia coreana (Gentianaceae), a new species from Korea: Evidence from morphological and molecular data. Phytotaxa. 403: 86-98.