• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.1
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• pp.1-6
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• 1993

This experiment was conducted to select acid tolerant cells from red clover suspension culture and obtained following results. The most effective condition of plant growth regulators for suspension culture of red clover cells was 2 mg/l 2,4-D as auxin source plus 0.5 mg/l BAP as cytokinin source. Among serveral basal media, PC medium brought the best result. The most suitable EMS concentration for the mutated cells tolerant to acid was 1 % with fours treatment and average 27 colonies/plate were selected. The frequency of the occurence of mutants tolerant to acid in 1 % EMS with four hours treatment was 8.9 $\times$ 10$^{-5}$ which was 100 times larger than that of control. The total colonies selected initially were 176 but the survived colonies after two subcultures with 4 weeks interval in a selection medium were 44.

• Korean Journal of Plant Resources
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• v.17 no.2
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• pp.153-160
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• 2004

Glehnia littoralis is known as an edible and medicinal plant using green loaves and mature roots of plant. In the present paper, the influence of plant growth regulators on callus induction and plant regeneration was investigated. Callus induction and regeneration occurred from leaf and petiole explants in Glehnia littoralis. Optimal condition of plant growth regulators for callus induction from leaf and petiole explants was MS basal medium supplemented with 2mg/L 2,4-D and 2mg/L BA. The frequency of callus induction was higher in petiole explant than leaf. When the callus was cultured on MS basal medium supplemented with 0∼1 mg/L IAA, 0∼1mg/L NAA and 0∼2mg/L BA for about 65 days, the most effective plant growth regulators on plant regeneration from callus were 1mg/L NAA and 2mg/L BA. The plantlets acclimatized successfully and grown in vermiculite matrix.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.286-290
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• 2010

C-1 compounds are observed in anaerobic sediment of high salt environments. Thus, surface sediments and waters from these environments are therefore potential habitats for aerobic methylotrophic microorganisms. The soil samples collected from saltern and tidal flat as inoculums and methanol as carbon and energy source was supplied. After subculture depending on the salt concentration, methanol oxidizing bacteria growth condition investigated, the results of methanol oxidizing bacteria can grow in salt conditions, and the maximum concentration was 20%. Analysis based on denaturing gradient gel electrophoresis of 16S rRNA genes indicates that Methelyophaga-like bacteria were dominants of methylotrophs in the enrichment culture. Quantitative PCR showed that archaeal cells were about 1-10% of bacterial cells. Additionally archaea were assumed not to be involved in methanol oxidation since bacterial antibiotics completely blocked the methanol oxidation. Our results suggest that Methelyophaga-like bacteria could be involved in C-1 compounds oxidation in hypersaline environments although those activities are sensitive to salinity above 20%.

• Korean Journal of Veterinary Research
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• v.41 no.2
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• pp.167-172
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• 2001

The present study was conducted to examine morphological and biological characteristics of 57 strains of Microsporum canis isolated from 110 dogs with dermatophytosis in Taegu, 1999. Isolated strains of M canis were classified into 4 types(A: white-yellow type, B: fluffy type, C: flat type, D: radial groove type) according to their pigmentation and morphology of colonies with typical conidia and hyphae. Some strains of A and B type happened variation by subculture for 6~8 months. The variation strains were classified into 3 types(E, F, G), E type had aberrant macroconidia with typical macroconidia, F type had aberrant hyphae(like dumb-bell) and macroconidia, and G type had no conidia and racket hyphae. All strains showed positive urease test, rice medium growth test and hair perforation test.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.5
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• pp.288-292
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• 2007

Seafood, if eaten raw, carries the risk of food poisoning. Seafood poisoning is often caused by pathogenic microorganisms originating from fecal contamination, such as Salmonella sp. and norovirus. Fecal coliforms are an important indicator of fecal contamination. Therefore, data on fecal coliforms are very important for evaluating the safety of fisheries in coastal areas. In this study, 2,226 sea water samples were collected from the southeast coast of Korea, and total and fecal coliforms were compared and analyzed. Total coliforms were detected in 76.5% of the samples and 71.4% of the total coliforms were fecal coliforms. At sea water temperatures above $20.0^{\circ}C$, total coliforms were found in 78.8% of the samples and fecal coliforms constituted 72.0% of the total coliforms. In sea water below $19.9^{\circ}C$, the respective values were 74.6% and 70.9%. These results suggest that temperature does not have a significant effect on the detection of fecal coliforms. When the salinity exceeded 30.0%o, total coliforms were found in 72.1% of the samples and fecal coliforms constituted 66.0% of these. At salinities below 29.9%o, the respective values for total and fecal coliforms were 90.4% and 85.2%. These results strongly suggest that the detection of fecal coliforms is proportional to the amount of precipitation.

• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.430-434
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• 1997

Axillary bud explants from 3-year-old seedlings of Forsythia saxatilis N., rare and endangered species in Korea, were cultured on Murashige and Skoog's medium. The effect of various cytokinins(BAP, kinetin, and zeatin) at the different concentration(0.2, 0.5 and 1.0mg/L) was tested. Although an apparent shoot proliferation was not observed, zeatin showed slight promotional effect on normal shoot and leaf development. Both shoots and adventive roots could be induced simultaneously when the explants were cultured on the medium with kinetin, but adventive rooting was gradually reduced according as BAP and zeatin concentrations increased. Axillary shoot growth was promoted by the etiolation treatment. Shoot proliferation has been maintained more than three years with consecutive subculture. Rooted plantlets were successfully acclimatized in the artificial soil mixture and showed normal growth after transplantation into field.

• Transactions of the KSME C: Technology and Education
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• v.3 no.1
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• pp.29-36
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• 2015

Some major companies representing Korea's ship building actively take part in building Oil & Gas offshore which produces both oil and gas from the ocean. Merchant ships become enlarge and high-powered electric as well as increasing number of Oil & Gas offshore. Thus, maritime university cadets are pushed to participate in onboard training on 440V to 6,660V high voltage ships. Although they have difficulty and danger from onboard training course on high voltage ships, their curriculum is still focusing on the training on low voltage ships. Therefore, this study is to suggest the upcoming education measures based on the questionnaire survey and analysis from the Maritime cadets who had experienced in high voltage ships.

• Korean Journal of Plant Resources
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• v.11 no.1
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• pp.9-14
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• 1998

Two types of somatic embryos were directly induced from the immature zygotic embryos of the wild prunus yedoensis in Mt. Halla after 16 weeks of culture on MS medium supplemented with 0.1mg/L $GA_3$ and 0.1mg/L BAPor 0.5mg/L $GA_3$ and 0.1mg/L BAP. One was normal single embryo with a single basal part. Normal somatic embryos germinated successfully on 1/2 MS medium. However, abnormal nulticotyledonary somatic embryos, formed shoots only on hormone free MS medium and about 80% of shoots rooted on MS medium with 0.5mg/L IBA. The mximum frequency (62.5%) of normal somatic embryos was directly obtained from the zygotic embryo 30 days after full blooming but it was decreased with further maturation.

• Korean Journal of Plant Resources
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• v.21 no.4
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• pp.341-345
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• 2008

Two orchid species of Calanthe discolor Lindl. and C. discolor for. sieboldii (Decne.) Ohwi, which have different form flower color and size. They were crossed in mid April by artificial pollination, and the F1 hybrid seeds were collected mid October. Germination of seeds was investigated on pre-treatment of seeds and under the various environmental conditions. Germination was promoted by moisture absorption and ultrasonic treatment of seeds. Dark culture of F1 hybrid seeds enhanced germination and protocorm formation, and development into seedlings compared with light culture. Although, plant growth regulators such as NAA and BA had a slightly promotive effect on seed germination and protocorm growth, regenerated seeding were showed abnormal growth patterns. Regenerated F1 hybrid plantlets were successfully transferred to pot.

• Journal of Life Science
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• v.17 no.10
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• pp.1336-1340
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• 2007

The regeneration and growth of bulblets from the bulb scale segments of Hyacinthus orientalis L. cv. Pink Pearl were more efficient in IBA than IAA at the same concentrations (1.0 and 3.0 mg/l). The normal (base-down) orientation of explants was more effective for bulblet regeneration and root growth than the inverted (base-up) orientation. The growth of bulblets and roots was increased higher in the perlite than the agar medium. These results suggested that the alternate culture system, first cultured in the agar medium for bulblet regeneration, and then in the perlite medium for bulblet growth, may be more useful for efficient in vitro culture of hyacinth (H. orientalils) cv. Pink Pearl.