• 한국자원식물학회지
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• 제28권6호
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• pp.697-703
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• 2015

Twenty apple germplasm accessions from the Korean Genebank were successfully cryopreserved using two-step freezing to back up genetic resources maintained by field collections. This study examined the morphological and genetic stability of cryopreserved dormant apple buds that were stored in liquid nitrogen, and then rewarmed and regrown. Whole plants were regenerated directly from dormant buds through budding without an intermediary callus phase. The cryopreserved buds produced high levels of shoot formation (76.2-100%), similar to those of noncryopreserved buds (91.3-100%), with no observed differences between cryopreserved and noncryopreserved materials. Three of the twenty cryopreserved apple germplasm accessions were used to assess morphological and genetic stability. No differences in morphological characteristics including shoot length, leaf shape, leaf width/length ratio, and root length were observed between controls (fresh control and noncryopreserved) and cryopreserved plantlets. The genetic stability of regenerants (before and after cryopreservation) was investigated using inter simple sequence repeat (ISSR) markers. The ISSR markers produced 253 bands using four primers, ISSR 810, SSR 835, ISSR 864, and ISSR 899. These markers showed monomorphic banding patterns and revealed no polymorphism between the mother plant and regenerants before and after cryopreservation, suggesting that cryopreservation using two-step freezing does not affect the genetic stability of apple germplasm. These results show that two-step freezing cryopreservation is a practical method for long-term storage of apple germplasms.

• Parasites, Hosts and Diseases
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• 제57권3호
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• pp.257-264
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• 2019

We tried a series of morphological and molecular approaches to identify a new species of Stellantchasmus (Digenea: Heterophyidae) originating from the wrestling half-beaked fish, Dermogenys pusillus of Thailand. Adult worm samples of the new species were recovered from hamsters experimentally infected with the metacercariae from D. pusillus in Thailand. Two isolates (Thai and Korean) of Stellantchasmus falcatus were used as comparative control groups. Worm samples of 3 Stellantchasmus groups were morphologically observed and molecularly analyzed with the mitochondrial cytochrome c oxidase 1 gene. The morphological characteristics of S. dermogenysi n. sp. are similar to S. falcatus originating from brackish water fish, but minor difference was noted including the absence of the prepharynx, position of the ovary near the ceca end, smaller body size, and shorter esophageal length. A phylogenetic tree derived from neighbor-joining and maximum-likelihood methods suggests that S. dermogenysi n. sp. is separated from S. falcatus supported by high bootstrap values. The relative divergences persist between these host-specific trematodes, which we suggest should be recognized as 2 distinct species. Comparisons of S. dermogenysi n. sp. with S. falcatus isolated from mullets in Thailand and Korea indicate a genetic divergence of mitochondrial DNA of 19.4% and 21.7%, respectively. By the present study, a new species, Stellantchasmus dermogenysi n. sp. (Digenea: Heterophyidae), is proposed in Thailand based on molecular evidences, in addition to minor morphological differences between S. falcatus and the new species.

• 대한본초학회지
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• 제34권6호
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• pp.63-70
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• 2019

Objective : Arnebiae Radix, the roots of Arnebia euchroma (Royle) Johnst. or A. guttata Bunge, is a well-known traditional herbal medicine in East Asia. In the Korean Pharmacopoeia, three authentic species, including two Arnebia and Lithospermum erythrorhizon Sieb. et Zucc. have recognized as a Lithospermi Radix. But, the morphological and taxonomic information of two authentic Arnebia species lacks date since their distribution and difficulty of accessing the natural habitats. Methods : A full description of the external morphological characteristics of vegetative and reproductive organs in the original plants was carried out using digital calipers and stereoscope. For providing their taxonomic and nomenclatural synonyms, we reviewed various plant checklists and taxonomic literature. Results : This study provides taxonomic information of A. euchroma and A. guttata based on a morphological examination of authentic plant individuals and field observations. Detailed descriptions of the two Arnebia species, major quantitative and qualitative characteristics, nomenclatural reviews, distribution maps, and lists of voucher specimens examined are provided. The shape of leaves, root length, stem number, calyx length and pubescence as well as corolla color were useful characteristics for identification. Moreover, we confirmed that A. euchroma and A. guttata are clearly heterostylous species. Conclusion : Our research provides valuable basic information that could be used as quality control for distinguishing between Arnebiae Radix and its adulterants. These results will help in the understanding of authentic plants and also provide the verified materials and voucher information.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 춘계학술대회
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• pp.20-20
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• 2020

Eranthis stellata Maxim. is a perennial plant that grows around the valley. E. stellata is concerned about the decline in natural habitats due to climate change in KOREA, continues to be observed and protected as an endangered species (Least Concrned, LC). Nevertheless, studies on the characteristics of the seeds of E. stellata are insufficient. So, this study analyzed the morphological characteristics and dormancy types of seeds. Seeds of E. stellata was collected in April at Gyeongsangbuk-do Arboretum and kept at 5 ℃ until using. To investigate the morphology of seeds, an optical microscope and a scanning electron microscope (SEM) were used. GA3 treated or untreated seeds (4 replicates of 25 seeds each) were observed germination and embryo growth for 1 month at 5 ℃ and 25/15 ℃ (12h day/12h night). The seed surface of E. stellata, light brown, was observed as a common characteristic of Eranthis genus, reticulate. The short axis of seeds was 1.11~1.77mm (average 1.44mm), and the long axis was 1.27~1.91mm (average 1.63mm), which was investigated in a slightly round shape (subglose). While no germination was observed at all conditions, Embryo growth was observed at 5 ℃ both in the control group and with GA3treated groups. Thus, seeds of E. stellata are classified as morphological physiological dormancy (MDP), which requires embryonic development and dormant break at the same time. These results can be useful information for determining morphological physiological seed dormancy and germination, and will be an important basic data for seed propagation of E. stellata as a resource.

• 대한의생명과학회지
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• 제13권2호
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• pp.99-104
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• 2007

To determine whether 17$\beta$-estradiol induces the morphological changes in adipose and liver tissues, we measured the effects of 17$\beta$-estradiol on adipose tissue mass, adipocyte histology and hepatic lipid accumulation in female ovariectomized (OVX) C57BL/6J mice. Compared to vehicle-treated control mice, 17$\beta$-estradiol-treated mice decreased adipose tissue mass and the size of adipocytes, and concomitantly increased the number of adipocytes in a dose-dependent manner. In addition, the administration of 17$\beta$-estradiol resulted in reduced hepatic lipid accumulation in a dose-dependent manner. These results suggest that estrogen may regulate adipocyte development and lipid metabolism in female OVX C57BL/6J mice.

• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.1146-1151
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• 2005

The yeast Candida albicans has a distinguishing feature, dimorphism, which is the ability to switch between two morphological forms: a budding yeast form and a multicellular invasive filamentous form. This ability has been postulated to contribute to the virulence of this organism. Previously, we reported that the yeast-to-hypha transition in this organism is suppressed by farnesoic acid, a morphogenic autoregulatory substance that accumulates in the medium as the cells proliferate. In this study, using a differential display reverse transcription polymerase chain reaction (DDRT-PCR) technique, we have identified several genes induced in C. albicans by farnesoic acid treatment. These observations indicate that farnesoic acid can alter the expressivity of multiple genes, including the DNA replication machinery and cell-cycle-control proteins.

• 한국환경과학회지
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• 제6권1호
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• pp.53-60
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• 1997

The toxicity of purified ricln from Ricinus communis to rats was examined by histological and histochemical methods. Sprague-Dawley rats were injected intraperitoneally with 75$\mu\textrm{g}$/kg body weight of ricin and were sacrified at itntervals of 6, 24, 48 and 120 hours after injectoon. The major morphological changes, such as cloudy swelling, hydropic degeneration, necrosis, fatty change, blood congestion, increase of Kupffer cells in number and extension of sinusoids, were obvious in the liver of experimental group. These morphological changes of hepatic cells were mainly observed in both the periportal and midlobular region of hepatic lobule. The extension of sinusoids was obvious in the controlobular region. And glycogen dlstrlbution of hepatic cells tended to decrease in the same region showing morphlogical changes as compared with the control group.

• Applied Microscopy
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• 제43권2호
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• pp.81-87
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• 2013

The influence of carbide formation on mechanical properties has been investigated in carburized steels. Through controlled diffusion and precipitation processes, the morphologies of carbides could be changed and then fine, networked, and spherical shapes at carburized layers were obtained. These morphological changes affected tensile and bending fatigue properties of the steel. The fine and the spherical carbides acted as resistance sites against crack propagation, which improved the mechanical properties. However, the networked carbides deteriorated the properties because the cracks propagated along the boundaries of them. These results indicate that the morphological control of carbides is one of important keys to improve the mechanical properties.

• 한국환경보건학회지
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• 제28권4호
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• pp.1-5
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• 2002

Drosophila Kc cells are ecdysone-responsive : hormone treatment leads rapidly to increased synthesis of several ecdysone-inducible polypeptides (EIPs) and to commitment to eventual proloferative arrest. Later the treated cells undergo morphological transformation, cease to proliferate and to grow. These responses have proven useful as models for studying ecdysone action and environmental endocrine disrupting actions. In this study, we used 20-HE to check out the Kc cells properties to the ecdysone and this properties will be applied to the environmental chemicals to find out the endocrine disrupting action in ecosystem. The cell counts of cultures harvested after 3 days' growth in the presence of 20-hydroxyecdysone. In Kc cell cultures, there were statistically significant different from control cells at 20HE 10/sup 7/-10/sup 5/. The morphological effects of all the hormones were similar, differing only in the dose level at which they were initiated.

• 한국환경과학회지
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• 제27권9호
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• pp.771-780
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• 2018

To develope a microbial weed control agent, HCN-producing bacteria were isolated, and their characteristics were investigated. A selected strain of WA15 was identified as Pseudomonas koreensis by morphological, cultural, biochemical and 16S rRNA gene analyses. The conditions for HCN production was investigated by a One-Variable-at-a-Time (OVT) method. The optimal HCN production conditions were tryptone 1%, glycine 0.06%, NaCl 1%, and an initial pH and temperature of 5.0 and $30^{\circ}C$, respectively. The major component for HCN production was glycine. Under optimal conditions, HCN production was about 3 times higher than that of the basal medium. The WA15 strain had physiological activities, such as indoleacetic acid that was associated with the elongation of plant roots and siderophore and ammonification inhibiting fungal growth, and produced hydrolytic enzymes, such as cellulase, pectinase and lipase. The strain was able to inhibit the growth of phytopathogenic fungi, such as Rhizoctonia solani, Botrytis cinerea and Fusarium oxysporum, by the synergistic action of volatile HCN and diffusible antimicrobial compounds. A microscopic observation of R. solani that was teated with the WA15 strain showed morphological abnormalities of fungal mycelia, which could explain the role of the antimicrobial metabolites that were produced by the WA15 strain. The volatile HCN produced by the WA15 strain was also found to have insecticidal activity against termites. Our results indicate that Pseudomonas koreensis WA15 can be applied as a microbial agent for weed control and also as a termite repellent. Furthermore, it could be applied as a microbial termiticidal agent to replace synthetic insecticides.