• Korean Journal of Plant Taxonomy
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• v.49 no.3
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• pp.224-239
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• 2019

Species identification for the Korean tribe Desmodieae was conducted using the DNA barcoding genes rbcL, matK (from chloroplast DNA) and ITS (from nuclear ribosomal DNA). A total of 25 taxa (n = 75) in five genera were sequenced, and neighbor-joining trees were constructed using different combinations of DNA barcodes. When comparing these phylogenetic trees, a tree with all loci combined (rbcL + matK + ITS) showed the highest rate of identification success (72%). On this tree, two subtribes and five genera within the tribe were supported as monophyletic. In the Desmodiinae clade, Desmodium and Hylodesmum were more closely related to each other than to Ohwia. In the Hylodesmum clade, H. oldhamii was found to be a sister to H. podocarpum complex, and all taxa within the complex were identified successfully. Subsp. fallax, regarded as a variety of subsp. oxyphyllum, is closely clustered with subsp. podocarpum. Although var. mandshuricum has been regarded as a synonym of var. oxyphyllum, this taxon is supported as a distinct variety. For the Lespedezinae clade, all species of Kummerowia were monophyletic, while nine of 16 Lespedeza taxa were identified successfully. In particular, the resolution of Macrolespedeza (28.5%) was lower than that of Junceae (77.8%). Among the Lespedeza taxa, L. cuneata was distinguishable from L. lichiyuniae, despite morphological similarities. It has been suggested that both L. maritima and L. inschanica are hybrids. The former is thought to be an independent species. While it is difficult to determine whether the latter originated via hybridization, this study showed that it is closely related to L. juncea.

• Korean Journal of Ecology and Environment
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• v.56 no.1
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• pp.36-44
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• 2023

Environmental DNA (eDNA) can exist in both intracellular and extracellular forms in natural ecosystems. When targeting harmful cyanobacteria, extracellular eDNA indicates the presence of traces of cyanobacteria, while intracellular eDNA indicates the potential for cyanobacteria to occur. However, identifying the "actual" potential for harmful cyanobacteria to occur is difficult using the existing sediment eDNA analysis method, which uses silica beads and cannot distinguish between these two forms of eDNA. This study analyzes the applicability of a density gradient centrifugation method (Ludox method) that can selectively analyze intracellular eDNA in sediment to overcome the limitations of conventional sediment eDNA analysis. PCR was used to amplify the extracted eDNA based on the two different methods, and the relative amount of gene amplification was compared using electrophoresis and Image J application. While the conventional bead beating method uses sediment as it is to extract eDNA, it is unknown whether the mic gene amplified from eDNA exists in the cyanobacterial cell or only outside of the cell. However, since the Ludox method concentrates the intracellular eDNA of the sediment through filtration and density gradient, only the mic gene present in the cyanobacteria cells could be amplified. Furthermore, the bead beating method can analyze up to 1 g of sediment at a time, whereas the Ludox method can analyze 5 g to 30 g at a time. This gram of sediments makes it possible to search for even a small amount of mic gene that cannot be searched by conventional bead beating method. In this study, the Ludox method secured sufficient intracellular gene concentration and clearly distinguished intracellular and extracellular eDNA, enabling more accurate and detailed potential analysis. By using the Ludox method for environmental RNA expression and next-generation sequencing (NGS) of harmful cyanobacteria in the sediment, it will be possible to analyze the potential more realistically.

• Korean Journal of Ichthyology
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• v.34 no.3
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• pp.186-200
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• 2022

In order to understand the species composition and distribution characteristics of larval assemblages in the East Sea, Korea, larvae were collected at 13 stations every other month from February to December 2018. Fish larvae were identified through DNA barcoding along with morphological methods, and as the result, a total of 104 taxonomic groups appeared during the survey. Among these, Engraulis japonicus, which accounted for 76.2% of the total population, was the most dominant species, followed by Maurolicus japonicus, which accounted for 15.0%. In addition, Ammodytes personatus, Champsodon snyderi, Scomber japonicus and Echelus uropterus appeared more frequently than other taxa. The above six species accounted for 93.2% of the total catch. The number of taxa and the amount of larvae collected in the survey area were higher during the high water temperature periods (June to October) than during the low water temperature periods (February, April and December). Analysis of similarity (ANOSIM) showed a statistically significant difference in monthly larval assemblages. The results of the canonical correspondence analysis (CCA) show that the distributions of larval community were mainly affected by sea surface temperature during low water temperature periods, and various environmental factors such as salinity, dry weight of zooplankton, and the concentrations of nutrients during high water temperature periods.