• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.3
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• pp.307-313
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• 2009

Mature dry seeds of Korean cultivars, Daepungkong, Muhankong, Myeongjunamulkong, Somyeongkong, Sowonkong, Jinpumkong, and Pungsannamulkong were used. The influence of antibiotics on elimination of Agrobacterium growth and shoot regeneration was estimated with cotyledonary node. Cefotaxime and timentin at the concentration of 250 and 500 mg/l suppressed Agrobacterium, especially cefotaxime was an efficient antibiotic to suppress Agrobacterium in all cultivars. While carbenicillin and timentin at the concentration of 50 and 100 mg/l were not sufficient to control the development of Agrobacterium, respectively. Cefotaxime and timentin represented high shoot formation rates compared with carbenicillin. Carbenicillin at low concentrations did not effectively suppress Agrobacterium and also had no effect on shoot development. Cefotaxime at the concentration of 250 mg/l showed maximum frequency of shoot regeneration in cvs. Somyeongkong and Sowonkong. Furthermore, on medium containing cefotaxime, shoot was more quickly formed than the other antibiotics. The use of cefotaxime was very useful for elimination of Agrobacterium growth with cotyledonary node of Korean soybean cultivars.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.2
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• pp.18-25
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• 2008

The current display systems including TVs are going digital and large-sized, and high visual quality of those systems becomes a very important selling point in the current display system market. Thus, various researches have been carried out for enhancing the visual quality of digital display systems. One of the important digital image(or video) enhancement techniques is sharpness enhancement, and it is generally based on a transient improvement technique that reduces the edge transition time. However, this technique often generates overshoot and undershoot, which cause undesirable pixel-level changes around the transient improved edge. In this paper, we propose a new nonlinear filter-based adaptive shoot elimination method for effectively suppressing the overshoot and undershoot that occur in the transient improvement, so that we can obtain visually sharper and clearer digital images(or videos). The proposed method uses two orthogonal directional min/max nonlinear filters with an adaptive shoot elimination scheme in order to effectively suppress the visually sensitive overshoot and undershoot. Experimental results show that the proposed method suppresses the overshoot and undershoot almost perfectly while maintaining the effect of the transient improvement. The applications of the proposed method include digital TVs, digital monitors, digital cameras/camcoders, portable media players(PMP), etc.

• Journal of Plant Biotechnology
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• v.43 no.3
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• pp.391-396
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• 2016

In this study, in vitro-cultured 'Mansoo' pear (Pyrus pyrifolia L.) plants infected with Apple stem grooving virus (ASGV) were used for testing the efficiency of the virus elimination methods. The shoot tips cut from infected plants were treated by thermotherapy ($37^{\circ}C$), cold therapy ($4^{\circ}C$), chemotherapy with ribavirin, and combination of these methods. Treatment periods were 2, 4, and 8 weeks, and concentrations of ribavirin were 20 and $40mg{\cdot}L^{-1}$. The efficiency of ASGV elimination was evaluated by reverse transcription polymerase chain reaction. The shoot survival rate was the highest at 100% after cold therapy, chemotherapy, and combination of two methods, while the rate was the lowest at 33.3% after thermotherapy for 2 weeks. The shoot survival rate after chemotherapy decreased gradually as the treatment period was prolonged. The ASGV elimination rate was the highest at 100% after ribavirin treatment at a concentration of $40mg{\cdot}L^{-1}$ and combination of ribavirin treatment and thermotherapy for 2 weeks, whereas the ASGV elimination rate after cold therapy was the lowest at 16.7%. However, the efficiency of ASGV elimination was enhanced up to 43.3% by the combination of cold therapy and ribavirin treatment. The efficiency of ASGV elimination for all treatments was increased as the treatment period was prolonged. Based on these results, we suggest that ribavirin treatment at a concentration of $20mg{\cdot}L^{-1}$ for 4 weeks or at a concentration of $40mg{\cdot}L^{-1}$ for 2 weeks combined with shoot tip culture was efficient for the elimination of ASGV from pear.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.155-160
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• 2003

Grapevine leafroll-associated virus 3(GLRaV-3) is one of the most severe pathogens for viral diseases found in Korea. This study was conducted to establish the virus-free stock production system for the virus disease control. The effects of thermotherapy, merestem culture and chemotheratpy to eliminate the GLRaV-3 in gratevines were tested. Thermotherapy at 37$\pm$2$^{\circ}C$ for 6∼8 weeks combined with 0.5∼1.0mm size of meristem culture method was the most effective for virus elimination. Thermotherapy alone was not effective. In chemotheratpy, DHT and Amantadine (20, 40mg/L) treatment in medium was more effective than Ribavirin to eliminate the GLRaV-3 in grapevine. However, Ribavirin spraying to potted was not available for virus elimination. Therefore, virus-free stock production system using the thermotherapy combined with shoot apical meristem culture was the most effective in grapevine.

• Plant Resources
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• v.7 no.3
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• pp.200-205
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• 2004

Sweet potato infected with a viral disease (SPFMV) showed irregular chlorotic patterns, so called feathering associated with faint or distinct ring spots that have purple-pigmented borders. SPFMV was eliminated from sweet potato plants using meristem tip culture. MS medium supplemented with BAP (2mg/L) and NAA (0.05 mg/L) was used for shoot proliferation and 1/2 MS medium for rooting of the plants. Highest percentage of regenerated plants (60%) was obtained from the optimum size (0.3-0.5mm) meristem tips. Of these, 60% plants were found negative for SPFMV by RT-PCR. Virus detection by RT-PCR was found to be a reliable method. Meristem-tip culture to produce SPFMV-free quality sweet potato and virus detection by RT-PCR is an efficient, time saving and reliable method for production of SPFMV-free tissue culture raised plants.

• Journal of Plant Biotechnology
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• v.49 no.3
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• pp.222-229
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• 2022

Apples are the most grown fruit crops in the fruit industry of Korea. However, virus or viroid infection such as apple mosaic virus (ApMV), apple stem grooving capillovirus (ASGV), apple stem pitting virus (ASPV), apple chlorotic leaf spot virus (ACLSV), apple scar skin viroid (ASSVd) causes fruit yield reduction and poor fruit quality. Therefore, in this study, we examined to established an efficient virus-free system to eliminate the most infected ASGV virus in domestic apple orchard. We investigated that the shoot growth rate and the virus removal rate in ASGV infected potted apples that were treated with heat treatment in a growth chamber (constant temperature/humidity device) maintained at 36℃, 38℃ and 40℃ for 4 weeks. Here we found that the shoot growth rate was the highest in the heat treatment group (36℃) and the virus was removed in the middle and top of the shoot but not in the bottom. The virus was did not removed in the 38℃ and 40℃ heat treatment group in all section of shoots, and the heat treatment group (40℃) died after 4 weeks of heat treatment without growth of shoots. We performed in vivo shoot-tip grafting using the shoot-tip of potted apple heat-treated at 36 ℃, and we also investigated the viability and virus removal rate, which showed 94% viability and 20% virus removal rate. Collectively, our results suggest that it would be possible to produce the virus-free apple plants through heat treatment and shoot-tip grafting.

• Journal of Plant Biotechnology
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• v.5 no.4
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• pp.239-244
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• 2003

A protocol has been developed for rapid large scale clonal propagation of an aromatic endangered medicinal plant, Hemidesmus indicus R. Br. with the elimination of the problems such as premature leaf fall and callus formation during caulogenesis and rhizogenesis. Multiple shoots were induced from shoot tip and nodal explants on Murashige and Skoog (MS) medium supplemented with 1 mg/L Benzylaminopurine (BAP) and 0.5 mg/L Napthaleneaceticacid (NAA). Addition of 15 mg/L adenine sulphate to the above medium checked leaf abscission completely, reduced the time required for caulogenesis and restored morphogenetic potential after several subcultures. The in vitro grown propagules were rooted in 1/2 MS medium supplemented with 2 mg/L Indolebutyric acid (IBA) +1 mg/L NAA and sucrose 0.7% (w/v). Addition of charcoal at 100 mg/L to the rooting medium quickened root initiation with a complete check on callus formation. The effect of sucrose concentration on both caulogenesis and rhizogenesis was also studied. The resultant plantlets were acclimatized and grown in fields where ninety eight percent of the rooted shoots survived and grew normally. The estimation of the secondary metabolite content in the shoots of the regenerated plant and the mother plant indicated that the concentration of the three secondary metabolites lupeol, vanillin and rutin was similar.

• The Korean Journal of Ecology
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• v.27 no.1
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• pp.43-47
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• 2004

This research was investigated to prepare basic data in a study on the copper tolerance of herbaceous plants through the growth rate and the elimination rate dependent on Cu concentration of 6 species; Commelina communis, Medicago sativa, Echinochloa frumentancea, Zea mays, Helianthus annuus and Abutilon avicennae, We examined the germination rate, root and shoot growth of seedling and fresh biomass of 6 species (Commelina communis, Medicago sativa, Echinochloa frumentancea, Zea mays, Helianthus annuus and Abutilon avicennae) painted to Cu contaminated soil (50, 100, 200, 300-CuCl₂/㎏) and control for 14 days. The germination rate of H. annuus, E. frumentancea and C. communis were not affected by Cu concentration. However, root and shoot growth of H. annuus was about 7% of control and the biomass was 35% of control at 300 ㎎-CuCl₂/㎏. E. frumentancea and C. communis that showed good growth rate at higher Cu contaminated soil (>200 -CuCl₂/㎏), were the most tolerant plant to Cu concentration. Especially, E. frumentancea eliminated over 30% of Cu in soil and the amount of Cu uptake increased with increasing Cu concentration; 1,020㎎ Cu per 1 ㎏ of soil at 300 ㎎-CuCl₂/㎏. From these results, we concluded that E. frumentancea would be used for phytoremediation.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.388-393
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• 2017

We report an Agrobacterium-mediated transformation procedure optimized for 'Kyoho' that is a major table grapevine cultivar in Korea, and its transgenic plants with antifreeze protein gene of carrot (DcAFP). The full length of DcAFP coding region in accordance with the previous report was isolated from young leaves of carrot and recombined into a plant transformation vector. Ethylene inhibitors such as silver nitrate and aminoethoxyvinylglycin (AVG) supplemented in a co-cultivation medium distinctly increased frequency of shoot regeneration when explants were sub-cultured in a selection medium: particularly ten-fold higher in treatment with 0.1 mg/L AVG than one without ethylene inhibitor. Among various antibiotics and their concentrations, the combination of 150 mg/L cefotaxime plus 150 mg/L $Clavamox^{TM}$ was selected for elimination of Agrobacterium cells in addition to minimization of adverse effect on shoot regeneration, while 50 mg/L kanamycin monosulfate effectively suppressed regeneration of non-transgenic shoots. Applying the elucidated culture condition, we finally obtained a total of 5 transgenic 'Kyoho' plantlets with DcAFP, of which integration with the grapevine genome and transcription was confirmed by nucleic acid analyses.

• Journal of Plant Biotechnology
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• v.40 no.1
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• pp.37-42
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• 2013

Rice is one of the most important cereal crops as a model plant for functional genomics of monocotyledons and usually transformed using Agrobacterium tumefaciens. However, the transformation's process using previous method is still time consuming and uneconomical, low efficiency. In this study, we established a new method by modifying the general Agrobacterium protocol especially in the infection and co-cultivation, Agrobacterium elimination, infected calli's selection steps using liquid media. We directly inoculated Agrobacterium containing a ZjLsL gene under the control of constitutive promoter into the 1- to 3-week-old rice calli derived from mature seeds. After 3 days of co-cultivation, the infected calli were transferred onto liquid media of Agrobacterium elimination and calli's selection for 3 days. The calli were transferred to calli's growth solid media for 14 days and then the calli transferred to shoot induction and root induction media. Putative transformants were initially selected on the medium containing phosphinothricin, and the PAT protein verified by PAT strip test. This method in this study would lead to reduction of substantial labor and time to generate transgenic plants.