• Korean Journal of Plant Tissue Culture
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• v.21 no.4
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• pp.215-220
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• 1994

Pollen-derived embryos cultured on the hormone-free medium showed a low germination frequency (12.5%) and poor growth response after germination. The greatest frequency of germination (81.3%) was obtained from the embryos cultured on medium with 0.3mg/L GA$_3$.The greatest frequency of generation (81.3) was obtained from embryos cultured on medium with 0.3mg/L GA$_3$. The embryos precultured for 20 days on medium with 0.3mg/L GA$_3$were transferred to the medium with various combination of hormones such as IAA, kinetin, zeatin, 6-benzylaminopurin (BA) and Gh$_3$. The germination frequency of cotyledonary stage embryos showed above 72% on media with all of the hormonal combinations, but the embryos germinated on medium with 2mg/L BA or 0.1mg/L kinetin and 0.3mg/L GA$_3$ developed more vigorously into plantlets than those of other hormonal combinations. Torpedo-stage embryos cultured on medium with 0.3 mg/L Gh$_3$ were pretreated for 8 weeks at 2-week intervals at 4$^{\circ}C$, The germination frequency of the cold-preheated embryos increased with the increment of pretreatment period from 2 to 8 weeks. The greatest frequency of germination (73.3%) was obtained from the embryos pretreated for 8 weeks at 4$^{\circ}C$. The chromosomes of the root-tip cells of W plane grown for 40 days after germination were observed. Most of the regenerated plants were haploid (55.8%) or diploid (315%), but triploid (1.3%), tetraploid (5.2%), or aneuploid (6.5%) were also detected among them.

• Journal of Bio-Environment Control
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• v.11 no.3
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• pp.139-143
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• 2002

Cotton Glutathione S-Transferase (GST: EC 2.5.1.18) was cloned and overexpressed in tobacco (Nicotiana tabacum) plants. Northern blot analysis confirmed the successful transformation of cotton gst gene in tobacco plant. Type I and Type ll transcript patterns were identified in transgenic tobacco plants and only Type I transcripts were discussed in this paper, The activity of GST in the type II transgenic plants was about 1.5-fold higher than those of the wild type and non-expresser by using 1-chloro-2,4-dinitrobenzene (CDNB) and reduced glutathione as the substrate. The expression of cotton GST in tobacco plants proved that Gh-5 could be translated into functional protein. Type II transgenic plants produced functional GST in the cells. The effects of cotton GST in the seedlings was evaluated by growing the control and transgenic seedlings at $15^{\circ}C$ in the growth chamber in the light. Overexpressors were grown well compared to the control plants (non-expressors). lo test far tolerance to salinity, seeds of Gh-5 overexpressors and the wild type Xanthi seedlings were grown at 0, 50, 100, 150, and 200 mM NaCl solution. Gh-5 transgenic seedlings showed higher growth rate over control seedlings on 50 and 100 mM NaCl solution. There was no difference in growth rate at 150 and 200mM NaCl concentration.

• Environmental Mutagens and Carcinogens
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• v.26 no.3
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• pp.63-68
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• 2006

There are $10{\sim}30%$ polyphenol and $2{\sim}4%$ caffeine in green tea. Caffeine is a kind of alkaloid containing nitrogen which cause stimulation, impatience, headache, insomnia, low birth weight infant. Because of these negative effect, decaffeined beverage came out and decaffeined coffee already have a big market since 1970s. Having proving the physiologic functions of green tea, high consumption of coffee is shifting to green tea. Because of the carcinogenic effect of the organic solvents, decaffeine processing with supercritical carbon dioxide has industrialized and have an advantage in environment-friendly and minimized flavor loss. Decaffeined green tea using supercritical carbon dioxide is considered to be safe but there are not enough study, We investigated the chromosome aberration test with mammalian cell line, CHL. When the cells were treated with 5000, 2000, 1000 ${\mu}g/ml$ and compared with the negative controls, there were no significant (P>0.05) increased chromosome aberration. Same results was observed when adding S9 mixture or not. As a result, water extract of decaffeined green tea using supercritical carbon dioxide does not induce chromosome aberration.

• Journal of Preventive Medicine and Public Health
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• v.31 no.4 s.63
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• pp.616-627
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• 1998

In order to evaluate the cytogenetic hazard among hospital workers potentially exposed to low dose of radiation, the analysis of chromosome aberrations(CA) and sister chromatid exchanges(SCE) in lymphocytes were performed in 79 hospital workers and 79 non-exposed workers. The mean frequency of chromosomal exchange and deletion(respectively, $0.20\times10^{-2}/cell\;and\;0.39\times10^{-2}/cell$) in the exposed group were significantly higher than those$(0.07\times10^{-2}/cell\;and\;0.23\times10^{-2}/cell)$ in control group. The frequency of sister chromatid exchanges was 5.04/cell in the control vs. 6.57/cell in the exposed group. There were also significant differences in the mean frequencies of CA and SCE adjusted for age, sex, smoking, drinking between two groups. There were no evidence of significant increase of CA and SCE according to the department or duration of employment. But the frequency of cells having chromosome aberration was significantly higher in the exposed group than in the control group related to duration of employment. There was no dose-effect relationship between the cumulative doses and the frequency of CA and SCE. But in the case of last 1 yr cumulative dose, there were evidence of significant dose-dependant increase of chromosome type CA and percentage of cells with aberration. The result suggest that there is cytogenetic hazard in risk group like hospital workers handling low dose radiation. And the analysis CA and SCE are useful biological indicators for the exposure of low dose level of radiation.

• Horticultural Science & Technology
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• v.19 no.3
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• pp.315-319
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• 2001

The study was carried out to develop a simple and efficient system to regenerate plants from cotyledon and hypocotyl tissues of Chinese cabbage (Brassica campestris L. ssp. pekinensis cv Seoul). Among the various combinations of naphthalene acetic acid (NAA) and 6-benzyladenine (BA) tested, the best shoot induction medium for cotyledon, with 2.67 shoots per explants, contained $2.0mg{\cdot}L^{-1}$ NAA, $1.0mg{\cdot}L^{-1}$ BA and $16.7mg{\cdot}L^{-1}$ $AgNO_3$. The shoot induction medium with $1.0mg{\cdot}L^{-1}$ NAA, $5.0mg{\cdot}L^{-1}$ BA and $16.7mg{\cdot}L^{-1}$ $AgNO_3$, was best for shoot induction from hypocotyl explants, with 1.87 shoots per explants. After shoot induction, regenerated shoots were excised and rooted on rooting medium. Rooted plantlets were then hardened in the high humidity growth chamber and transplanted to pots, and then grown in the greenhouse. Regenerated plants appeared phenotypically normal and there were no changes in chromosome number.

• Journal of Radiation Protection and Research
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• v.22 no.3
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• pp.195-205
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• 1997

This paper is to assess the effect of Adaptagen as a radioprotector in which main component is alkaloid fraction of ginseng. Evaluation was made in vitro and in vivo study with NIGP(S) mouse by the measurement of regeneration of jejunal crypt cell and micronucleus assay to analyze radioprotective effect of ginseng alkaloid fraction in comparison with that of water fraction after whole body irradiation. The results were as follows, 1. The degree of radiation damage of mouse jejunal crypt cell was diminished in both of alkaloid and water fraction groups compared to control group but more in alkaloid fraction group than water fraction group. Regeneration of mouse jejunal crypt cell was higher both in alkaloid and water fraction groups than control group. 3. In vitro study, frequency of micronucleus was diminished in tendency for the treated groups than control group but statistically insignificant. 4. In vitro study, frequency of micronucleus was diminished in both alkaloid and water fraction groups compared to control group but more in alkaloid fraction group than water fraction group.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.762-768
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• 2004

Chromium has been known to be involved in the glucose metabolism, and hence the utilization of cellular glucose is impaired in the chromium deficiency. Chromium has been recognized as an essential nutrient since the finding of low-molecular-weight Cr-binding substance (LMWCr) as a biological modifier of insulin action. Clinical chromium deficiency associated with glucose intolerance that respond to the administration of chromium. The major impediment to the use of orally administered chromium is poor absorption of trivalent chromium in its inorganic form. Trivalent chromium is more available in yeast md, more recently, as chromium picolinate for oral absorption. The widespread use of these supplements has resulted in controversy regarding chromium's role as a nutrient, its use for treatment of insulin resistance, and its potential toxicity. Most recent evidence strongly supports tile conclusion that there is little fear of toxic reactions from chromium consumption. This report reviews the evidence for the potential toxicity of chromium supplements in contrast with its usefulness as a nutrient or therapeutic agent in the treatment or prevention of insulin resistance.

• Journal of Aquaculture
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• v.13 no.4
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• pp.331-338
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• 2000

To establish an alternate technology for all male seed production of Nile tilapia, Oreochromis niloticus at hatchery scale, the performance of progenies produced by crossing superfemale with sex reversed male was evaluated. Free crossings between 21 superfemales and 7 sex reversed males stocked in an aquarium for 60 days resulted in the production of 93.5 % male progenies, compared to 53.2 % males produced by an equal number of normal females and normal males. Spawning frequency was lower (19 times) in the experimental cross including superfemales than that (24 times) in the control including normal females. Seed production in the experimental aquarium was (3,085) significantly lower than that (3,797) of the control. Both in terms of seeds per female per day or seeds per g female per day, seed productivity did not significantly differ between these groups. The alternate technology involving crossing between superfemale and sex reversed male has proven to be an efficient alternate technology for mass production of all male seeds at the hatchery scale.

• Journal of Aquaculture
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• v.13 no.4
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• pp.325-330
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• 2000

For development of all male seed production at hatchery scale, a comparative study was made on the seed production traits of supermale (IT - t) and superfemale (IT - L1 ~) Nile tilapia, Oreochromis niloticus. Supermales were crossed with normal females (XX- f) and the superfemales with normal males (XY - t ) or sex reversed males (XX- L1 t); progeny survival of these crossings and sex ratio were evaluated. Hatching success of the eggs, fertilized by the supermale was significantly lower than that by the normal male. Over 95-99 % progenies sired by crossing supermales with normal females were males, while 52-55 % progenies alone were males with the cross of normal males and normal females. Hatching success and survival of alevins were significantly higher for the progenies of the crosses between superfemales and sex reversed males than those resulting from the crosses between superfemales and normal males. However, there was no significant difference in the sex ratio among the progenies of these crosses. Therefore, crossings of superfemales with sex reversed males provide the highest percentage of survival and male progenies.

• Journal of Plant Biotechnology
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• v.45 no.3
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• pp.242-249
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• 2018

This study was conducted to develop an SNP set that can be useful for marker-assisted breeding (MAB) in watermelon (Citrullus. lanatus L) using Genotyping-by-sequencing (GBS) analysis of 20 commercial elite watermelon inbreds. The result of GBS showed that 77% of approximately 1.1 billion raw reads were mapped on the watermelon genome with an average mapping region of about 4,000 Kb, which indicated genome coverage of 2.3%. After the filtering process, a total of 2,670 SNPs with an average depth of 31.57 and the PIC (Polymorphic Information Content) value of 0.1~0.38 for 20 elite inbreds were obtained. Among those SNPs, 55 SNPs (5 SNPs per chromosome that are equally distributed on each chromosome) were selected. For the understanding genetic relationship of 20 elite inbreds, PCA (Principal Component Analysis) was carried out with 55 SNPs, which resulted in the classification of inbreds into 4 groups based on PC1 (52%) and PC2 (11%), thus causing differentiation between the inbreds. A similar classification pattern for PCA was observed from hierarchical clustering analysis. The SNP set developed in this study has the potential for application to cultivar identification, F1 seed purity test, and marker-assisted backcross (MABC) not only for 20 elite inbreds but also for diverse resources for watermelon breeding.