• Animal cells and systems
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• v.4 no.4
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• pp.319-324
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• 2000

Species boundaries among the Alcyonacean soft coral, the genus Dendronephthya, are often obscured by inter- and intraspecific morphological variations. In the present study, we attempted to infer the genetic relationships of eight dendronephthians based on their molecular characters, the internal transcribed spacer (ITS) regions of ribosomal DNA, and then compared this result together with the random amplified polymorphic DNA (RAPD) data from our previous investigation. Dendronephthya. putteri and D. suensoni formed a divaricate form - VI grade specific clade, whereas D. castanea, D. gigantea, D. aurea and D. spinifera, formed a umbellate and glomerate form - IV and III grade specific clade. Therefore, we confirmed that the main characters the growth form and the anthocodial grade and formula, are important in identification of the species in dendronephthians despite some problems. Also, the relationships of the growth form are clarified as the glomerate form is much closer to the umbellate form than to the divaricate form based on two sets of independent molecular data. However, we cannot determine the molecular markers which limit the species boundaries among this genus with ITS sequences.

• Journal of Plant Biology
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• v.39 no.1
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• pp.1-8
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• 1996

Sequences from the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA were determined to assess their potential as a phylogenetic tool for Korean Acer species, including A. okamotoannum and A. takesimense which are endemic on Ullung Island of volcanic origin. Although the genus Acer has been studied by various authors, different infrageneric dispositions have been suggested, and the phylogeny of the genus has been in dispute. The variation of ITS sequences from seven species of Acer was very low among species within the same section, but comparative analysesof the molecular data obtained suggest that ITS sequences may provide enough phylogenetic resolution for sectional relationships in the genus.

• Korean Journal of Plant Taxonomy
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• v.53 no.1
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• pp.32-37
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• 2023

Spiraea prunifolia f. simpliciflora Nakai is a perennial shrub widely used for horticultural and medicinal purposes. We simultaneously obtained the complete plastid genome (plastome) and nuclear ribosomal gene transcription units, 45S nuclear ribosomal DNA (nrDNA) and 5S nrDNA of S. prunifolia f. simpliciflora, using Illumina short-read data. The plastome is 155,984 bp in length with a canonical quadripartite structure consisting of 84,417 bp of a large single-copy region, 18,887 bp of a short single-copy region, and 26,340 bp of two inverted repeat regions. Overall, a total of 113 genes (79 protein-coding genes, 30 tRNAs, and four rRNAs) were annotated in the plastome. The 45S nrDNA transcription unit is 5,848 bp in length: 1,809 bp, 161 bp, and 3,397 bp for 18S, 5.8S, and 26S, respectively, and 261 bp and 220 bp for internal transcribed spacer (ITS) 1 and ITS 2 regions, respectively. The 5S nrDNA unit is 512 bp, including 121 bp of 5S rRNA and 391 bp of intergenic spacer regions. Phylogenetic analyses showed that the genus Spiraea was monophyletic and sister to the clade of Sibiraea angustata, Petrophytum caespitosum and Kelseya uniflora. Within the genus Spiraea, the sections Calospira and Spiraea were monophyletic, but the sect. Glomerati was nested within the sect. Chamaedryon. In the sect. Glomerati, S. prunifolia f. simpliciflora formed a subclade with S. media, and the subclade was sister to S. thunbergii and S. mongolica. The close relationship between S. prunifolia f. simpliciflora and S. media was also supported by the nrDNA phylogeny, indicating that the plastome and nrDNA sequences assembled in this study belong to the genus Spiraea. The newly reported complete plastome and nrDNA transcription unit sequences of S. prunifolia f. simpliciflora provide useful information for further phylogenetic and evolutionary studies of the genus Spiraea, as well as the family Rosaceae.

• Molecules and Cells
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• v.23 no.2
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• pp.220-227
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• 2007

The development of suitable genetic markers would be useful for defining species and delineating the species boundaries of morphologically indistinguishable sponges. In this study, genetic variation in the sequences of nuclear rDNA and the mitochondrial cytochrome c oxidase subunit 1 and 3 (CO1 and CO3) regions were compared in morphologically indistinguishable Korean Halichondriidae sponges in order to determine the most suitable species-specific molecular marker region. The maximal congeneric nucleotide divergences of Halichondriidae sponges in CO1 and CO3 are similar to those found among anthozoan cnidarians, but they are 2- to 8-fold lower than those found among genera of other triploblastic metazoans. Ribosomal internal transcribed spacer regions (ITS: ITS1 + ITS2) showed higher congeneric variation (17.28% in ITS1 and 10.29% in ITS2) than those of CO1 and CO3. Use of the guidelines for species thresholds suggested in the recent literature indicates that the mtDNA regions are not appropriate for use as species-specific DNA markers for the Halichondriidae sponges, whereas the rDNA ITS regions are suitable because ITS exhibits a low level of intraspecific variation and a relatively high level of interspecific variation. In addition, to test the reliability of the ITS regions for identifying Halichondriidae sponges by PCR, a species-specific multiplex PCR primer set was developed.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.519-525
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• 1998

Intraspecific genetic diversity of Korean isolates of Phytophthora drechsleri was investigated based on PCR-RFLP of rDNA along with closely related species in the genus; P. cryptogea, P. melonis, P. erythroseptica, P. cinnamomi, P. cambivora and P. cactorum. Gene regions of nuclear small subunit and internal transcribed spacer (ITS) in rDNA were amplified with polymerase chain reaction and digested with 9 restriction enzymes. Phytophthora species was readily differentiated from each other based on the digestion patterns, however, P. cryptogea was not separable from some isolates of P. drechsleri. Twenty one isolates of P. drechsleri originated from 15 host plants were divided into three distinct groups designated as PdG1, PdG2 and PdG3, respectively. Four isolates in PdG1 were originated from green vegetables and tomato and nine isolates in PdG2 were mainly isolated from medicinal plants. The two groups showed 95.3% homology and four isolates of P. cyptogea came under the groups. However, Eight isolates in PdG3 collected from cucurbits were clearly differentiated from those of PdG1 and PdG2 by 66.5% homology, but completely matched with a Taiwan isolate of P. melonis. Results indicated that three distinct groups exist in Korean isolates of P. drechleri and each group has host preference. In addition, reclassification of the cucurbits isolates are reserved because of their distinct genetic characters from other intraspecific groups in P. drechsleri.

• The Korea Journal of Herbology
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• v.24 no.4
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• pp.1-8
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• 2009

Objectives : This study was carried out to discriminate origin and molecular marker of oriental medicine "Cnidii Rhizoma" be circulated between Korea and China, which is difficult to discriminate from morphological distinction because of a fragmental materials of roots. Methods : Materials were collected randomly from a medicinal herb markets in Korea and China and be analyzed with ITS (internal transcribed spacer) regions of nuclear ribosomal DNA (nrDNA). Results : As a results, ITS regions of nrDNA was shown to be identify as three molecular markers. "Cnidii Rhizoma" was made up syster group of the genus Ligusticum L. and divided into three groups with "Tou-chun-gung", "IL-chun-gung" and "China-chun-gung". Conclusions : From the analysis of ITS regions of nrDNA, we presumed that it is the same origin of "Cnidii Rhizoma" from Korea and China because of phylogenetic tree consisted of sister groups with the genus Ligusticum than the genus Cnidium.

• Animal cells and systems
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• v.16 no.2
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• pp.145-153
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• 2012

The pear psylla, $Cacopsylla$ $pyricola$ (Hemiptera: Psyllidae), is a serious insect pest of commercial pear crops. The species, which resides on pear trees throughout its life cycle, is rapidly spreading in some regions of the world. The population genetic structure of the species collected from several pear orchards in Korea was studied to understand the nature of dispersal and field ecology of the species. The 658-bp region of mitochondrial COI gene and the 716-bp long complete internal transcribed spacer 2 (ITS2) of the nuclear ribosomal DNA were sequenced. Unlike other previously studied insect pests, the COI-based genetic diversity of the pear psylla was extremely low (maximum sequence divergence of 0.15%). This finding allowed us to conclude that the species may have been introduced in Korea relatively recently. ITS2 sequence-based analyses of phylogeny, population differentiation, gene flow, and hierarchical population structure all concordantly suggested that the pear psylla populations in Korea are neither genetically isolated nor hampered for gene flow. These genetic data are concordant with the dispersal of an overwintering winterform morph outside the non-pear habitat in the fall.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.471-472
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• 2001

Recently many studies show that genetic characters can be used to provide unambiguous taxonomic discrimination when morphological characters are not practical for routine identification to species level (Bucklin et al., 1996, 1998; Lindeque et al., 1999). The internal transcribed spacer (ITS) regions of the nuclear ribosomal DNA are also one of appropriate markers for species-level studies because it contains sufficient diversity to address intra- and interspecific phylogenetic relationships in invertebrates (Odorico and Miller,1997; Schizas et al., 1999). (omitted)

• Journal of Species Research
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• v.1 no.2
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• pp.232-239
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• 2012

Taxonomy of umbelliferous taxa Heracleum moellendorffii complex has been unclear in their species delimitation in the far-eastern Asian regions. In both Korea and China Heracleum moellendorffii was adopted for their description while H. sphondylium was chosen to describe Japanese Heracleum. From Genbank accessions, taxa collected from Kamtchatka and Promorskiy, Russia were defined as H. maximum, endemic taxon to North America. In this study, we reviewed the taxonomy of Heracleum moellendorffii complex in Korea and neighboring countries on the basis of molecular phylogenies derived from sequences of nuclear ribosomal DNA internal transcribed spacer (ITS) regions. From three Korean accessions of Heracleum investigated in this study, two types of ITS sequences were obtained; two accessions were related to Chinese H. moellendorffii var. moellendorffii and North American H. maximum without forming a clade while the other one was identical to accession from H. maximum from Primorskiy, Russia. In the other hand, Japanese H. moellendorffii (=H. sphondylium ssp. sphondylium var. nipponicum in the flora of Japan) was closely related to H. maximum accessions from Korea and Russia, not nested within the clade comprising several subspecies of H. sphondylium. In order to delimit species boundaries among putatively closely related Heracleum species in fareastern Asian countries, more samples and much more rapidly evolved DNA regions must be investigated with interpretation of morphological and anatomical features.

• Korean Journal of Plant Resources
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• v.27 no.6
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• pp.671-679
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• 2014

Molecular phylogenetic analyses of Korean Elaeagnus L. were conducted using seven species, one variety, one forma and four outgroups to evaluate their relationships and phylogeny. The sequences of internal transcribed spacer regions in nuclear ribosomal DNA were employed to construct phylogenetic relationships using maximum parsimony (MP) and Bayesian analysis. Molecular phylogenetic analysis revealed that Korean Elaeagnus was a polyphyly. E. umbellata var. coreana formed a subclade with E. umbellata. Additionally, the genetic difference between E. submacrophylla and E. macrophylla was very low. Moreover, E. submacrophylla formed a branch from E. macrophylla, indicating that E. submacrophylla can be regarded as a variety. However, several populations of this species were not clustered as a single clade; therefore, further study should be conducted using other molecular markers. Although E. glabra f. oxyphylla was distinct in morphological characters of leaf shape with E. glabra. But E. glabra f. oxyphylla was formed one clade by molecular phylogenetic with E. glabra. Additionally, this study clearly demonstrated that E. pungens occurs in Korea, although it was previously reported near South Korea in Japan and China. According to the results of ITS regions analyses, it showed a resolution and to verify the relationship between interspecies of Korean Elaeagnus.