• Korean Journal of Plant Tissue Culture
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• v.21 no.2
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• pp.99-103
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• 1994

The herbicide bialaphos is a potent inhibitor of glutamine synthetase in higher plants. A bialaphos resistance (bar) gene encoding for an acetyltransferase was isolated from genomic DNA of Pseudomonas syringae pv tabaci. The bar gene was ligated to the binary vector pBI121. Pistils of tobacco plane were heated with the bar gene containing plasmid DNA at various times after pollination. When the treatment was applied at 30 and 40 h after pollination, a number of transgenic plants were obtained. Premary transformation (T$_{0}$ generation) and their progenies (T$_1$T$_2$) were resistant to both bialaphos and kanamycin at a dosage lathal to untransformed control plants. Stable integration of bar gene into chromosomal DNA was proven by Southern blot analysis of genomic DNA isolated from T$_1$progenies. These results show that the bialaphos resistant plane could be obtained by treatment to pistils with the exgenous bar gene through the fertilization cycle of tobacco.o.

• Journal of fish pathology
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• v.26 no.1
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• pp.39-44
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• 2013

Saprolegnia isolate from wild brook lamprey was identified on the basis of its morphological and molecular characteristics. The isolates showed aseptic hyphae and clavate zoosporagium. Zoospores discharge was typically saprolegnoid. Neither oogomia nor antheridia was observed in this study. ITS sequence obtained from the isolate was compared with other Saprolegnia spp. to analyse their phylogenetic relationships. Results showed that the isolate belongs to clade I including Saprolegnia parasitica. Based on the asexual organs, zoospore discharge manner and ITS sequence analysis, the isolate was identified as S. parasitica.

• Journal of Korean Society of Forest Science
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• v.90 no.2
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• pp.169-175
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• 2001

Genomic DNAs were extracted from the leaves of 182 ginkgo trees (Ginkgo biloba L.) planted in 6 regions and subjected to the analysis of both I-SSR and RAPD markers. A total of 227 amplicon variants were generated by PCR using 15 I-SSR primers and 67 amplicons by PCR with 5 RAPD primers. Levels of genetic diversity within 6 populations were turned out to be similar (Shannon's Index, I-SSR : 0.35~0.40; mean of 0.38, RAPD : 0.31~0.38; mean of 0.35, combined : 0.35~0.40; mean of 0.37). Ranks of the level of genetic diversity estimated from I-SSR, RAPD, and combined data were not coincided each other. Majority of genetic diversity was allocated among individuals within populations (I-SSR : 94.31%, RAPD : 93.62%, combined : 93.57%), which resulted in pretty low level of population differentiation. Genetic differentiation between male and female groups was turned out to be quite low (I-SSR : 0.03, RAPD : 0.091, combined : 0.043), which slightly fluctuated when analysis was restricted to the data obtained from 3 regions where both male and female trees were sampled (I-SSR : 0.038, RAPD : 0.084, combined : 0.047). Genetic relationships among the populations, reconstructed by UPGMA, were not coincided with geographic affinity, which might be resulted from sharing of seed sources in some regions. Whereas independent cluster analyses with I-SSR data and RAPD data, respectively, reclassified by sexes revealed two sexual groups in which all the male and the female populations were clustered together, cluster analysis with combined data did not show clear sexual grouping.

• The Korean Journal of Mycology
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• v.24 no.3 s.78
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• pp.186-205
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• 1996

This study was carried out to obtain data concerning the genetic variability of Pleurotus ostreatus. Monospores of P. ostreatus were isolated and cultured to estimate differences in the rate of mycelial growth and genetic similarity among the isolates. Although the overall growth rates were slow compared to their parental dikaryon except 2-MI 4, significant differences in the rate of mycelial growth were observed among isolates. Random amplified polymorphic DNA (RAPD) analysis using twenty six random primers showed 345 polymorphic DNA bands from 35 monospore isolates and their parental dikaryon. DNA bands ranged from 0.1 to 4.0 Kb in size. Most various polymorphic DNA bands within monospore isolates were obtained when we used J (OPA-01) or W (OPB-04). The 36-MI 103 showed totally different band patterns from those of the others. RAPD analysis revealed that there is approximatly 75% genetic similarity between monospore isolates and their parental dikaryon except 36-MI 103, which showed only 49% genetic similarity. In addition, genetic similarity degrees were classified into four groups: I (parental dikaryon), II (fast growing type), III (moderate growing type), and IV (slow growing type). However, there is no correlation between mating type and mycelial growth rates.

• Development and Reproduction
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• v.7 no.2
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• pp.61-68
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• 2003

Zygote genome should entail a complex process of epigenetic reprogramming including a global DNA demethylation to reach a totipotency or pluripotency during early mammalian development. In this study, we have analyzed methylation patterns in cloned bovine embryos to monitor the epigenetic reprogramming process of donor genomic DNA. Aberrant DNA methylation patterns were observed in various genomic regions of cloned embryos except single-copy gene sequences. The overall genomic methylation status of cloned embryos was quite different from that of normal embryos produced in viかo or in vivo. Abnormal methylation profiles were also specifically represented in trophectoderm cells of cloned embryos, which probably result in widespread gene dysregulation in extraembryonic region or placental dysfunction familiar to cloned animals. Our findings suggest that developmental failures of cloned embryos are due to incomplete epigenetic reprogramming of donor genomic DNA. Understanding the epigenetic reprogramming processes of donor genome will clearly define the faulty development of cloned embryos.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.877-881
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• 2007

The genetic diversity and population structure of Potentilla freyniana in Korea were determined using genetic variations at 19 allozyme loci. Thirteen of the 19 loci (68.4%) showed detectable polymorphism. Genetic diversity at the population level was high ($H_{EP}$ = 0.270). Total genetic diversity values ($H_T$) varied between 0.190 and 0.584, giving an average overall polymorphic loci of 0.371. The interlocus variation of genetic diversity within populations ($H_S$) was high (0.354). On a per locus basis, the proportion of total genetic variation due to differences among populations ($G_{ST}$) ranged from 0.008 for Fe-2 to 0.310 for Gpi with a mean of 0.065, indicating that about 6.5% of the total allozyme variation was among populations. Wide geographic ranges, perennial herbaceous nature and the persistence of multiple generations are associated with the high level of genetic variation in P. freyniana. The estimate of gene flow based on $G_{ST}$, was high among Korean populations of P. freyniana (Nm =3.57). Although P. freyniana usually propagated by asexually-produced ramets, I could not rule out the possibility that sexual reproduction occurred at a low rate because each ramet may produce terminal flowers.

• Korean Journal of Medicinal Crop Science
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• v.10 no.1
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• pp.5-11
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• 2002

The study of genetic diversity was carried out in Atractylodes japonica $K_{OIDZ}$. Although this species has been regarded as medically important one, there is no report on population structure in Korea. Starch gel electrophoresis was used to investigate the allozyme variation and genetic structure of eight Korean populations of this species. Of the 15 genetic loci surveyed, nine (60.0%) was polymorphic in at least one population. Genetic diversity was high at the species level $(H_{es}=0.144)$, whereas, that of the population level was relatively low $(H_{ep}=0.128)$. Nearly 87% of the total genetic diversity in A. japonica was apportioned within populations. The sexual reproduction, high fecundity, and perennials are proposed as possible factors contributing to high genetic diversity. The indirect estimated of gene flow based on Gst was 1.69.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.6
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• pp.261-267
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• 2023

Crystal structure, microstructure, and dielectric properties of the (Ca, Sr)(Zr, Ti)O₃ (CSZT) system has been studied as a function of sintering temperature and MgO addition for microwave applications. A single-phase CSZT powder with the orthorhombic crystal structure was obtained by the solid-state reaction method. The powder compacts were sintered at 1200℃, 1300℃, and 1400℃ respectively. All the sintered samples had a single-phase orthorhombic crystal structure and grain size increased with sintering temperature. In the case of 1 mol% MgO addition, the orthorhombic crystal structure was the main phase; however, a secondary phase appeared during sintering at 1400℃, as determined by EDS analysis. At 1400℃, the undoped and MgO-doped CSZT had almost similar grain size distribution and densification but the grain size distribution became slightly narrow. The MgO-doped CSZT showed excellent low-loss dielectric properties: ε_r = 34.14, tanδ = 0.00047, τ_ε = -3.58 ppm/℃ at 1 MHz.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.423-432
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• 2019

In order to select potential plant resources as functional materials and natural antioxidants, we evaluated antioxidant activity and serotonin derivatives of safflower germplasm collected from five countries. N-(p-Coumaroyl) serotonin (CS) and N-feruloylserotonin (FS) were analyzed by using Ultra Performance Liquid Chromatography (UPLC). Total polyphenol content (TPC) was determined by Folin-Ciocalteu method and antioxidant activities were estimated by 2,2-diphenyl-1-picryl-hydrazil (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), Ferric reducing antioxidant power (FRAP) and Reducing power (RP) assays. The TPC showed a range of 28.25 to $90.53{\mu}g$ gallic acid equivalent (GAE)/mg dried extract (DE). DPPH, ABTS, FRAP and RP assay were in the range of 18.76 to 93.98, 48.91 to 163.73, 3.80 to 132.29 and 26.32 to $80.08{\mu}g$ ascorbic acid equivalent (ASCE)/mg DE, respectively. Among the five countries, safflower seed collected from Iran had the highest levels of serotonin derivatives and antioxidant activities than other countries (p<0.05). CS showed high correlation with TPC, ABTS and DPPH (r=0.673,0.727,0.820), and FS showed high correlation with DPPH (r=0.740). Accessions IT321214 and IT321215 could be useful for development of new functional materials and could be used as a source of valuable natural antioxidant materials.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.459-466
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• 2012

In order to improved treatment performance of dielectric barrier discharge (DBD) plasma, plasm + UV process and gas-liquid mixing method has been investigated. This study investigated the degradation of N, N-Dimethyl-4-nitrosoaniline (RNO, indicator of the generation of OH radical). The basic DBD plasma reactor of this study consisted of a plasma reactor (consist of quartz dielectric tube, titanium discharge (inner) and ground (outer) electrode), air and power supply system. Improvement of plasma reactor was done by the combined basic plasma reactor with the UV process, adapt of gas-liquid mixer. The effect of UV power of plasma + UV process (0~10 W), gas-liquid mixing existence and type of mixer, air flow rate (1~6 L/min), range of diffuser pore size (16~$160{\mu}m$), water circulation rate (2.8~9.4 L/min) and UV power of improved plasma + UV process (0~10 W) were evaluated. The experimental results showed that RNO degradation of optimum plasma + UV process was 7.36% higher than that of the basic plasma reactor. It was observed that the RNO decomposition of gas-liquid mixing method was higher than that of the plasma + UV process. Performance for RNO degradation with gas-liquid mixing method lie in: gas-liquid mixing type > pump type > basic reactor. RNO degradation of improved reactor which is adapted gas-liquid mixer of diffuser type showed increase of 17.42% removal efficiency. The optimum air flow rate, range of diffuser pore size and water circulation rate for the RNO degradation at improved reactor system were 4 L/min, 40~$100{\mu}m$ and 6.9 L/min, respectively. Synergistic effect of gas-liquid mixing plasma + UV process was found to be insignificant.