• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.311-319
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• 2011

Overusing chemical fertilizers involves potassium accumulation in the soil, which can become a toxicity problem in agriculture. This study was conducted to investigate the effect of potassium (K) treatment on growth, physiological characteristics, and morphological changes using Chinese cabbage (Brassica rapa L. ssp. campestris). With high (600 mM) K treatment, the plant growth traits of leaf length, leaf area, and fresh and dry weight of shoots and roots decreased, whereas chlorophyll content increased. As the concentration of K increasing, total N, P, and K increased in leaves, but concentrations of Ca, Mg, and Na decreased. However, Mn, Fe and Zn contents were highest in 100 mM K treatment. Chlorophyll a, b, and carotenoids increased with increasing K concentration. Maximum photochemical efficiency ($F_v/F_m$) was not significant in the all treatments, whereas $CO_2$ assimilation decreased with increasing K level due to stomatal degradation. Total free amino acids increased with the 10 and 100 mM K but decreased at 600 mM K treatments. Therefore, the growth and physiological characteristics of Chinese cabbage ascertained that tolerance up to 100 mM K when grown with nutrient solution in pot culture.

• Journal of Bio-Environment Control
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• v.18 no.2
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• pp.124-131
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• 2009

Surfactant polyvinyl alcohol (PVA-95) 1, 2, 4mg. $L^{-1}$ and calcium lignosulfonate (CLS) 5, 25, 50, 100mg. $L^{-1}$ were treated to the nutrient solution containing 1.0mg. $L^{-1}$ selenium (Se) to evaluate Se absorption effect using small DFT apparatus. The growth of leaf lettuce and pak-choi did not show unique significance by surfactant kinds and concentration in the tested range and physiological disorder. Vitamin C in leaves of two leafy vegetables was not significantly affected by surfactants also. Among major cations K content in pak-choi was highest in Se I+PVA-95 4mg. $L^{-1}$ treatment, and high in Se I+CLS 5 mg. $L^{-1}$ treatment. Ca content in two leafy vegetables showed increasing pattern by the two kinds of surfactants. Mg content was high in Se I+CLS 25mg. $L^{-1}$ treatment compared to control. Pak-choi absorbed Se about 10 times higher than leafy lettuce. Se content in leaves of two leafy vegetables increased by the treatment of two kinds of surfactants with the exception of CLS 100mg. $L^{-1}$ treatment.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.485-490
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• 2012

This study was carried out to investigate the plant growth of various foliage plants affected by the amount of nitrogen application. There was not an accurate criterion for fertilization to each foliage plant. Moreover, the foliage plants grow slowly during the early stage and this period must be shortened for commercial production. Ficus benjamina, Hedera helix, Philodendron tatei, Rhapis excelsa, and Spathiphyllum spp. were used in this experiment. Nutrient nitrogen concentrations were 120, 150, 180, and $210mg{\cdot}L^{-1}$ (N1, N2, N3, N4) and they were based on the Sonneveld solution. Plant height and width, leaf number, leaf area, fresh and dry weights of shoots were measured for 8 weeks to compare the responses to the different treatments. The nitrogen contents of various plant parts were also analyzed. The growth of Ficus and Hedera was improved at the N1 treatment and that of Philodendron, Rhapis and Spathiphyllum at N4 treatment. The required amounts for nitrogen nutrients were different among the various foliage plants. The nitrogen treatments had no effects on SPAD values and there were no correlations between nitrogen treatments and nitrogen contents of plant parts. Therefore, the various foliage plants should supply with each proper nitrogen treatments to grow faster with better quality. In this case, the plant growth played a more important role than nitrogen levels of plant parts in deciding the proper nitrogen levels for each foliage plant.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.566-571
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• 2005

A natural habitat bacterium, Enterobacter cloaceae K41 was isolated from fresh water plant root and identified. This strain was used to investigate heavy metal resistance. The optimal growth conditions of the bacterium were LB medium containing$1\%$ yeast extract, $1\%$ lactose, $1\%$ NaCl, pH 7.0, at $37^{\circ}C$, and for 24 hours on a shaker. The minimal inhibitory concentration (MIC) of heavy metals against E. cloaceae KCTC2519 and E. cloaceae K41 was compared. The MIC of E. cloaceae K41 was 150 ppm in Cu, 50 ppm in Cd whereas that of the standard strain was 50 ppm in Cu but no growth was observed either Cd or two mixed heavy metal solution. The presence of plasmid was cleared from the isolated strain whereas no possession from the standard strain. The plasmid from E. cloaceae K41 was transformed into E. coli $DH5{\alpha}$. The MIC of transformed strain increased resistance 7 times in Cu and 6 times in Cd by insertion of this plasmid. The metal adsorption of the transformant was increased 1.3 times in Cu and 1.5 times in Cd indicating the plasmid was responsible for heavy metal resistance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.189-195
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• 1997

To cope with increasing importance of water stress in food crop production, characteristics and cultivar differences in physiological responses of winter barley plants to water stress during seedling stage were studied employing three covered-barley, Milyang 12, Durubori, and Olbori, one naked-barley, Baekdong, and one two-row beer-barley, Hyangmaeg. Water stress was given to barley plants by withholding watering in soil-culture pots or by adding P.E.G. (polyethylene glycol, M. W. 4,000) to the nutrient culture solution. When water stress was imposed by withholding watering for 10 days to the seedlings grown in pot-soil for 10 days after emergence, leaf water potential of 5 cultivars was decreased almost to the same degree, from control -3.5 bar to the water stressed -26.6 bar. However, growth and some physiological responses were differently affected by cultivars: The plant height was decreased by 16-26％ : seedling dry weight by 25∼42％ ; chlorophyll content by 21∼39％ ; second leaf survival rate by 8∼18％ ; and free proline content per gram of leaf dry weight was increased from control 0.2∼0.5mg to the water stressed 5.8∼13.2mg. Drought resistances of 5 barley cultivars, based on the leaf survival rate and the decreased rate in seedling dry weight at the end of stress treatment, were high in the order of 3 covered-barley＞naked-barley＞two-row barley.

• Applied Biological Chemistry
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• v.11
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• pp.49-53
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• 1969

Some properties of glucose isomerizing enzyme which produced by the strain K-17 in xylose containing nutrient broth medium were investigated. The optimal pH for enzyme reaction was indicated about 7.2 and optimal temperature was about $75^{\circ}C$. The same optimal temprature was indicated by both cell free extract and acetone dried cells using as enzyme. The glucose isomerizing enzyme from strain K-17 was not inhibited by the high concentration of substrate even in a suturated glucose solution, but most enzyme was inactivated by the heat treatment at $80^{\circ}C$. The maximum fructose forming ratio from glucose was about 50 percents.

• Journal of Life Science
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• v.17 no.12
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• pp.1729-1733
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• 2007

Brassinolide insensitive associated receptor kinase 1(BAK1) is a critical component that play an important roles in signaling of brassinosteroid biosynthesis. Brassinosteroid-deficient and -insensitive mutants showed the characteristic of dwarf symptom. The nutrient deficient tomato showing stunt phenomenon was selected from soiless cultivation system using modified Sonneveld hydroponic solution. Twenty eight protein spots showing different expression levels compared to the control were isolated from extracts of stunted tomato leaves by 2D PAGE analyses. Significantly down-regulated 6 protein spots out of 28 protein spots were analyzed and sequenced by MALDI-TOF mass spectrometry. The protein spot having pI=4.5 and MW=24 kDa was identified as a signal protein, BAK1, which is directly related to brassinosteroid biosynthesis. In addition, five other protein spots were identified as BCK1, cystein proteinase, sulfutase, peroxidase and zinc finger factor respectively, and they were also signal proteins related to brassinosteroid biosynthesis. Furthermore, amplification of 500bp of BAK1 mRNA by RT-PCR using a primer set of peptide matched regions was inhibited conpared to that of the wild type. The results sugested that the BAK1 might be regulated at the transcription level in response to nutrition applications.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.409-414
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• 2010

The first drainage time in a day was controlled for precise irrigation management with low consumption of nutrient solution in tomato perlite bag culture system by measuring water level of drained water in drainage catchment part. This method automatically adjusted the irrigation time under any condition of light, temperature and humidity, resulting in stable water content in substrates. However, it was difficult to keep the time consistent as they were set. It drained with the deviation of 20 min in the treatment in which the first drainage time was set at 10:00 and 50 min in the treatment set at 10:30. The first drainage time was not constant, but the drain occurred stably before noon in the treatment of which irrigation frequency was longer than 30 min. The drainage ratio was better balanced in all the treatments using drainage level sensors than the treatment using time clock for irrigation control. High water and fertilizer efficiencies were obtained. Although the growth, total yield and sugar content were not significantly different between the treatments, fruit weight was higher in the treatments using drainage level sensors than that using timer.

• Journal of Bio-Environment Control
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• v.12 no.1
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• pp.7-11
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• 2003

Cellular glass foam (CGF), the reprocessed glass, has a possibility to be used as a medium component in plug culture of horticultural crops due to the its excellent air and water permeability as comparable to perlite. An experiment was conducted to investigate growth of plug seedlings of Lycopersicum esculentum 'Segye' as influenced by irrigation frequency in various medium combinations of CGF (2.0-4.0 mm particle size) and peatmoss. Seeds were sown in 200-cell plug trays, filled with mixtures of CGF and peatmoss either at 33：67 or 25：75 (％. v/v) and were germinated on a fogged propagation bed. The irrigation frequencies used were one, two or three times per every two days. A commercial plug medium (Tosilee medium) was used as the control, and the irrigation frequency in the control was one time per day. Growth of seedlings, and medium pH and EC were measured at 33 days after sowing. The medium composition had little influence on overall growth of seedlings. Irrigation frequency very significant affected number of leaves, leaf area, chlorophyll concentration, fresh and dry weights of shoots and roots, and dry matter. Growth of seedlings was the greatest with the highest irrigation frequency in the 25% CGF＋75% peatmoss mixture.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.414-423
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• 2016

Growers in plug seedling production think that root media in which rockwool is a component has given rise to several environmental problems. Therefore, the demand for new materials as a substitute for rockwool has been increased. This study examined the possibility of cultivation of tomato plug seedlings using a newly developed growing medium with phenolic foam. Plug seeds of tomato cultivar 'Madison' were sown in four pellet-type growing media: Grodan rockwool (GRW), UR rockwool (URW), phenolic foam LC (LC) or phenolic foam LC-lite (LC-lite). Then, the seedlings were transplanted to the four cube-type growing media 19 days after sowing. Seeds were germinated in a growth chamber ($25{\pm}2^{\circ}C$, 80% relative humidity, and dark) for 4 days and then the seedlings were grown with a nutrient solution supplied by an overhead irrigation system in a greenhouse. Plant height, number of leaves, leaf area, and fresh or dry weight of tomato seedlings were the greatest for the seedlings transplanted to URW cube media after being grown on LC-lite pellets. Root grade was the greatest for the seedlings transplanted on LC or LC-lite cube media after being grown on LC pellets. Chemical properties of all media tested for tomato growth were maintained within a stable range, while physical properties of URW showed high values in container capacity, air space, and total porosity. These results demonstrated that the phenolic foam media were effective for seedling growth and can substitute for rockwool as a root medium.