• Korean Journal of Organic Agriculture
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• v.8 no.1
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• pp.111-129
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• 1999

In order to get some basic data to check the environmental sound function against soil and water pollution and the safe vegetable production by korean organic farming where an internationally recognized basic concepts of soil fertility management for organic farming is not practiced and only applying the organic fertilizer to maintain the soil fertility, the chemical characteristics of soils and $NO_{3}^{-}$ content of chinese cabbage and lettuce cultivated by the conventional farming, greenhouse cultivation and organic farming were investigated. The highest value of $NO_{3}^{-}$-N in 0~30cm subsoil among the three different farming systems was found in the subsoil of organic farming and it was 3.6 and 6.6 times higher than those of conventional farming in chinese cabbage and lettuce respectively. $P_2O_5$ accumulation in the rhizosphere by organic farming also showed the highest value. The accumulation of $NO_{3}^{-}$-N and $P_2O_5$ in organic farming soil were similar or even more higher to those of greenhouse cultivation. The $NO_{3}^{-}$ accumulation in the vegetable by organic farming reached 3224ppm for chinese cabbage and 2543ppm for lettuce, and it were 4.7 and 6.4 times higher than those by conventional farming. It was concluded that there is urgently necessary to introduce the main concepts of soil fertility management of the Basic Standard of IFOAM, EU regulation and FAO/WHO Codex Alimentarius on organic agriculture(draft) into korean organic agriculture for the operation of environmental sound system and the production of sate vegetable in terms of $NO_{3}^{-}$ content.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.137-143
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• 2012

Chinese cabbage plant was grown hydroponically for 4 weeks in order to examine the temporal relationship of calcium concentration of the nutrient solution with calcium content in the leaf tissue and susceptibility of the tissue to soft rot disease by $Pectobacterium$ $carotovorum$ ssp. $carotovorum$ (Pcc). Calcium concentration from 0.5 to 32.0 mM was maintained for 1 week using Hoagland & Arnon solution. The calcium content of the leaf was proportionally increased to the concentration of the nutrient in the solution (r = 0.912). In contrast, the severity of soft rot symptom in the young leaves was inversely related with the amount of calcium supplied to the nutrient solution (r = 0.899). Water-soluble chitosan, prepared by hollow fiber filtration (> 100 kDa) was applied into the nutrient solution from 0.0 to 5,000 ppm. The chitosan of 10 ppm was the most effective to promote calcium uptake of the leaf, showing 155% of the control. The same chitosan solution prohibited most soft rot development of the leaf by Pcc, exhibiting only 53% of the control. Among different molecular weight fractions, chitosan fraction obtained from 30-100 kDa molecular weight cut-off promoted calcium uptake the most up to 163% of the control, and reduced the development of soft rot disease recording merely 36% of the control of the leaf tissue. The results obtained in the present study suggest that large scale production of water-soluble chitosan with an optimum molecular weight and its commercial application to Chinese cabbage production will be important to improve yield and quality of the crop.

• Korean Journal of Environmental Agriculture
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• v.23 no.3
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• pp.158-169
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• 2004

For the improvement of gas chromatographic analysis of multiple pesticide residues in green pepper, lettuce and Chinese cabbage, multiresidue test mixtures (MRTMs) of 10 groups (ECD 5 groups and NPD 5 groups) and a recovery test mixture (RTM) of 18 compounds (11 compounds for ECD and 7 compounds for NPD) were established based on retention time and response to relevant detectors. A new extraction solvent (acetone: acetonitrile=1 : 9) and a clean up eluent (hexane: dichloromethane : acetonitile = 50 : 48.5 : 1.5) for solid-phase extraction (SPE) cartridge were selected to test two types of multiresidue methods (MRM I and MRM II). MRM II provided high recovery better than MRM I when RTM was tested Recovery experiment with MRTMs which was conducted using MRM II resulted in that more than seventy percents of compounds were recovered in the range of $50{\sim}140%$, while 9% of compounds were over 140% of recovery and only $7{\sim}8$ compounds failed to detect. MRM II, an improved method, could be employed for screening residues of 190 pesticides in those vegetables.

• Korean Journal of Plant Tissue Culture
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• v.28 no.3
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• pp.153-157
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• 2001

Protoplasts were isolated from hypocotyls, cotyledons, and young leaves of Chinese cabbage grown under in vitro environmental condition. An enzyme mixture of 1% Cellulysin and 0.5% Macerozyme in combination with 0.4 M mannitol was most effective condition for protoplast isolation. The highest yield of protoplasts, 7.6$\times$10$^{5}$ protoplast/g of fresh weight, was obtained from the treatment of leaves for 12~16 hours at 27~28$^{\circ}C$ with shaking at 30 rpm. The most suitable medium for an initial cell division was K8p basal medium supplemented with 5 mg/L 2,4-D and 2 mg/L kinetin. Within 7~10 days, protoplasts derived from hypocotyl and cotyledon tissues formed cell colonies. When the cells were grown at the size of 8~10 cells, they were embedded into semi-solid medium containing 0.2% agarose. Calli derived from protoplast culture were transferred to the 100 different types of plant regeneration media, but no completely regenerated plants from inbred lines of Chinese cabbage used for this study wore obtained, though frequent rooting took place in several media tested.

• Journal of Plant Biotechnology
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• v.39 no.4
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• pp.253-260
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• 2012

On the basis of the reported agriculturally valuable phenotypes resulted from ectopic overexpression of Arabidopsis vacuolar $H^+$-PPase (AVP1), we generated the Chinese cabbage lines expressing AVP1 which then subjected to salt stress to determine the AVP1 expression if it consistently confers the capability for increasing biomass and enhancing tolerance to salinity in other species. Collectively, here we demonstrate that the transgenic young plants show more vigorous growth and higher tolerance to salt stress than wild-type ones. Increased biomass phenotype by AVP1 expression was supported by comparing fresh and dry weights of transgenic and wild type plants grown under normal condition, while higher salt tolerance trait was confirmed by tracing the kinetics of photosystem II quantum yield and DAB-staining under gradually intensified salt stress induced by MS salt or NaCl, followed by normal condition.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.3
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• pp.163-169
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• 2015

The level of nitrous oxide ($N_2O$), a long-lived greenhouse gas, in atmosphere has increased mainly due to anthropogenic sources, especially application of nitrogen fertilizers. Quantifying $N_2O$ emission in the agricultural field is essential to develop national inventories of greenhouse gases (GHGs) emission. The objective of this study was to develop an emission factor to estimate the direct $N_2O$ emission from an agricultural field cultivated with the Chinese cabbage during autumn season in 2010-2012. Emission factor of $N_2O$ calculated over three years experiment using accumulated $N_2O$ emission, nitrogen fertilization rate, and background $N_2O$ emission was $0.0058{\pm}0.00254kg\;N_2O-N\;kg^{-1}\;N$. More extensive studies need to be conducted to develop $N_2O$ emission factors for other upland crops in the various regions of Korea because $N_2O$ emission is influenced by many factors including climate characteristics, soil properties, and agricultural practices as well as crop species.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.684-693
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• 2014

Abiotic stress conditions such as cold, drought, and salinity trigger physiological and morphological changes and yield loss in plants. Hence, plants adapt to adverse environments by developing tolerance through complex regulation of genes related to various metabolic processes. This study was conducted to construct a coexpression network for multidirectional analysis of salt-stress response genes in Brassica rapa (Chinese cabbage). To construct the coexpression network, we collected KBGP-24K microarray data from the B. rapa EST and microarray database (BrEMD) and performed time-based expression analyses of B. rapa plants. The constructed coexpression network model showed 1,853 nodes, 5,740 edges, and 142 connected components (correlation coefficient > 0.85). On the basis of the significantly expressed genes in the network, we concluded that the development of salt tolerance is closely related to the activation of $Na^+$ transport by reactive oxygen species signaling and the accumulation of proline in Chinese cabbage.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.221-227
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• 2014

This study was investigated the change of pesticide residues in young Chinese cabbages and young radishes sprayed with pesticides (young Chinese cabbage: diazinon EC, dimethomorph WP and imidacloprid WP, young radish: diazinon EC, imidacloprid WP and procymidone WP) during Kimchi preparation and storage in Kimchi fridge ($1.8^{\circ}C$) for 67 days. Pesticide residues in young Chinese cabbages were removed by up to 31~52% through brining and washing, 57~74% through seasoning with ingredients, 61~76% through 14 hours storage at room temperature, and 70~82% through storage in Kimchi fridge. Pesticide residues in young radishes were removed by up to 57~85% through seasoning with ingredients, 59~86% through 17 hours storage at room temperature, and 74~91% through storage in Kimchi fridge. It means that brining and washing process was more efficient than fermentation process.

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.230.1-230
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• 1997

No Abstract, See Full Text

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1715-1724
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• 2015

The combined effects of a sanitizer mixture solution and antimicrobial ice on the quality of salted Chinese cabbages were examined. Salted Chinese cabbages were treated with a sanitizer mixture (comprised 50 ppm aqueous $ClO_2$ and 0.5% citric acid), packed in 2% brine and antimicrobial ice, and stored for 12 days at 4 and $10^{\circ}C$. Microbiological data on the salted Chinese cabbages after washing with the sanitizer mixture indicated that the populations of total aerobic bacteria, and yeast and molds decreased by 2.20 and 1.28 log CFU/g after treatment with the sanitizer mixture. In addition, coliforms population of salted Chinese cabbage after 12 days storage at $4^{\circ}C$ in the combined mixture of the sanitizer and antimicrobial ice was 3.22 log CFU/g, which was a significantly different from that of control (5.46 log CFU/g). The combined treatment of sanitizer mixture, antimicrobial ice, and low temperature at $4^{\circ}C$ suppressed reduction of pH and elevation of titratable acidity, resulting in delaying the growth of lactic acid bacteria. Differences in salinity, hardness, and Hunter's $L^*$, $a^*$, and $b^*$ values among treatments were negligible during storage at $4^{\circ}C$. Therefore, this study suggests that a combination of sanitizer mixture, antimicrobial ice treatment, and low temperature storage could improve the microbial safety and quality of salted Chinese cabbages during storage.