• Horticultural Science & Technology
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• v.29 no.3
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• pp.165-171
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• 2011

Plant growth retardants reduce the plant height by inhibiting stem elongation in Lilium davuricum. To investigate the plant hormones related to stem elongation, we sprayed 50 $mg{\cdot}L^{-1}$ diniconazole to young plants of L. davuricum and quantified the contents of endogenous gibberellic acids (GA) and abscisic acid (ABA). In GA biosynthesis, L. davuricum had not only the early C-13 hydroxylation ($GA_{19}{\rightarrow}GA_{20}{\rightarrow}GA_1$) pathway resulting in $GA_1$ as the active form but also the non C-13 hydroxylation (NCH, $GA_{12}{\rightarrow}GA_{24}{\rightarrow}GA_9{\rightarrow}GA_4$) with $GA_4$ as the active form. However, the main pathway was NCH because $GA_4$ concentration of 55 $ng{\cdot}g^{-1}$ dry wt was much higher than $GA_1$ content of 0.23 $ng{\cdot}g^{-1}$ dry wt in control plant. Diniconazole inhibited GA biosynthesis through NCH pathway from its early stage. $GA_{12}$ content decreased by diniconazole up to 6% level of that of control and this effect continued to $GA_4$. Diniconazole reduced $GA_{12}$ content by 12.7 $ng{\cdot}g^{-1}$ dry wt, whereas that of control plant was 213.8 $ng{\cdot}g^{-1}$ dry wt. ABA content decreased up to one third of control by diniconazole application. From the contents of endogenous $GA_4$, $GA_1$, and ABA in this study, we could conclude that diniconazole reduces the plant height by inhibiting $GA_4$ biosynthesis in L. davuricum.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.385-391
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• 2012

The growth of terminal shoots of persimmon (Diospyros kaki) was analyzed during the first two months from the time of bud sprout to understand the dynamics of their early growth. Field-grown, mature 'Fuyu' and 'Nishimurawase' trees were used in a three-year study at two locations in Gyeongnam province. The growth of terminal shoots was most active from late April, about 10 days after foliation, to early May, followed by a gradual decline by late May. The increase in leaf area continued unabated throughout May. The weight of a flower bud increased slowly until early May and rapidly after flowering. Although its extension growth had been ceased by late May, dry weight (DW) of a terminal shoot continued to increase almost linearly throughout May due to shoot thickening and continued growth of leaves and fruits. In late May, the leaves and the stem accounted for more than 60% and less than 20% of total DW of a shoot respectively; fruit proportion increased to 7 to 17% by then. Relative growth rate (RGR) of the terminal shoot was higher than 213 $mg{\cdot}g^{-1}{\cdot}d^{-1}$ in late April, but declined to less than 63 $mg{\cdot}g^{-1}{\cdot}d^{-1}$ in late May. Like the pattern of seasonal changes in RGR, net assimilation rate (NAR) of the shoots decreased from 1.9 to 2 $mg{\cdot}cm^{-2}{\cdot}d^{-1}$ to 0.5 to 0.8 $mg{\cdot}cm^{-2}{\cdot}d^{-1}$. An early-season 'Nishimurawase' did not differ from a late-season 'Fuyu' in RGR and NAR during the first two months of growth. The early growth of the shoots was affected mainly by the reserves redistributed from permanent organs, however, environmental conditions at the time was also involved.

• Korean Journal of Weed Science
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• v.17 no.3
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• pp.314-324
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• 1997

This study was conducted to investigate whether 1) photosynthetic pigments(chlorophylls and carotenoids) are formed in dodder plant(Cuscuta australis), 2) there are any characteristics in the pigment biosynthesis, compared to that of other normal plants, and 3) dodder responds to some herbicides having target site on chloroplast. 1. Chlorophyll content of dodder tendrill grown under a natural daylight was 9 times and 50 times lower than that of field bindweed stem and leaf, respectively. 2. The photosynthetic pigment contents varied in different tissues, being higher in a apical region than in a lower region of seedling or tendrill. Chlorophyll wasn't almost observed below the 4th internode from the upper. 3. Pigment contents were greatly dependent on light intensity so that there were 4 to 6 times difference among light conditions. When the shoot containning low pigment contents under natural light, was incubated in growth chamber with various light intensities, the pigment contents were increased by 3 times of initial contents at about 97${\mu}E$ $m^{-2}s^{-1}$PAR. While the change in pigment contents was not observed at above 450${\mu}E$ $m^{-2}s^{-1}$PAR 4. Exogenous supply of 5mM 5-aminolevulinic acid increased protochlorophyllide by 7 times and 1.4 times in the etiolated shoot from field bindweed rhizome and in dodder stem, respectively, showing that dodder relatively has a low response to 5-aminolevulinic acid. 5. Pigment loss was observed in the treatment of paraquat, norflurazon, oxyfluorfen and diuron, and protoporphyrin IX was accumulated by oxyfluorfen as in normal plants Based on above results, several chracteristics of pigment biosynthesis in dodder seem to be summerized as follows. Photosynthetic pigment biosynthesis in Cuscuta australis runs even in low level. The pigment contents is differentially distributed in different regions and their contents seem significantly to be controlled by light intensities. Especially, chloroplast rapidly tends to degenerate with the development of tissue. Some herbicides having target site on chloroplast induce damage to dodder stem but are unlikely to control it well in field, except paraquat, due to low chloroplast activity and parasitic mode of nutrition.

• Journal of Plant Biotechnology
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• v.39 no.2
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• pp.114-120
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• 2012

An efficient in vitro propagation was established by using axillary bud explants of roseroot (Rhodiola rosea L.), which has been known as a medicinal plant in East Asia. Among various media tested, MS medium supplemented with 1.0 mg/L BA and 1.0 mg/L $GA_3$ was found to be the best for multiple shoot formation (15 axillary shoots per axillary bud). In addition 1/2MS medium containing 50 g/L sucrose was best for shoot elongation (7.8 cm) and increasing total chlorophyll contents (8.64 mg/g) best. Maximum number of roots (17.7 roots per explant) was observed on the medium without plant growth regulators. Propagated plants were successfully acclimatized to ex vitro conditions, with a survival frequency of 97% after 12 weeks. Most rooted shoots grew well and produced viable seeds when grown in vitro culture conditions. Therefore, R. rosea can be effectively propagated in vitro by the system we developed in this study.

• Horticultural Science & Technology
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• v.31 no.3
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• pp.352-358
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• 2013

For the germination and differentiation of immature embryos obtained by artificial crossing between tetraploid grape 'Fujiminori' (Vitis vinifera ${\times}$ V. labruscana) and triploid 'Summer Black' (V. labruscana ${\times}$ V. vinifera), were incubated in vitro using MS medium supplemented with $GA_3$ or coconut water (CW) at various concentrations. The percentage of embryo formation of 'Fujiminori' ${\times}$ 'Summer Black' was 64.3%. Embryo germination percentage was higher than 95% in all the $GA_3$ treatments at the concentrations of 0.01, 0.05, 0.25, and $1.25mg{\cdot}L^{-1}$. However, only 15.8-31.6% of the germinated embryos successfully developed into normal plantlets. At higher concentration of $GA_3$, the plantlets developed infirm hypocotyls with over elongated and less enlarged structure. Among the treatments of CW at the concentrations of 5, 10, 15, and 20% (v/v), 10% and 15% were more effective and plantlet achievement percentage were 68.4 and 66.7%, respectively. The addition of 10% CW was most effective to obtain plantlets with optimal shoot length, node and root numbers. 15% CW was suitable to obtain plantlets with longer roots. Accordingly, the embryo culture using the MS medium supplemented with 10-15% CW was observed to be more efficient for germinating and growing the immature embryos produced from artificial crossing between tetraploid grape 'Fujiminori' and triploid 'Summer Black'.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.1
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• pp.63-67
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• 1987

A laboratory experiment was conducted to find out the concentration of phytotoxin in intensively cultivated hot-pepper, garlic and chinese cabbage, and effects of these phytotoxin to the germination and growth of young hot-pepper plant. Also this experiment presents describes of the bio-assay method and results of phytotoxin application to the toxicity of hot-pepper plant. The results obtained were summarized as follows; 1. A series of non-volatile (aromatic) phenolic compounds such as hydroquinone, benzoic-, p-hydroxybenzoic, and vanillic acid were quantitatively and qualitatively analysed using BSA(N, O-bis(trimethylsilyl)acetamide) by means of gas chromatography method. 2. Phytotoxin as hydroquinone, benzoic-, p-hydroxybenzoic- and vanillic acid were determined in intensively cultivated hot- pepper, garlic and chinese cabbage. Highest concentration of phytotoxin was obtained in hot-pepper cultivated soil. 3. Direct toxic action of the applied phytotoxin to the germination and young hot-pepper plant growth was observed at the levels of 200 ppm. Benzoic acid was obtained the highest toxicity to the young hot-pepper plant growth. 4. Mode of actions of phytotoxins to the young hot-pepper plant growth were observed as stunting of stem elongation, discoloration of leaf and oxygen depletion from consideration as causes of symptom.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.241-247
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• 2013

For in vitro minimal-growth conservation of S. sarmentosum, the in vitro shoots with 10 mm length were cultured on Murashige and Skoog's media (MS) containing different levels of agar (0.8, 1.2, 1.6, 2%), Gelrite (0.4, 0.6, 0.8, 1%), ABA (0, 5, 10, $20mg{\cdot}L^{-1}$), and sucrose (2, 3, 6, and 9%) without subculture at $4^{\circ}C$ and $25^{\circ}C$. All media were supplemented with $0.2mg{\cdot}L^{-1}$ BA, agar and Gelrite media, with 5% sucrose, sucrose media, with 1.2% agar, and ABA media, with 5% sucrose and 1.2% agar, respectively. In vitro minimal-growth conservation in room-temperature ($25^{\circ}C$) was effective in the media containing with $10mg{\cdot}L^{-1}$ ABA or 1.6% agar, and the healthy plantlets could be preserved for 10 months without subculture. After 12 months at $4^{\circ}C$, survival rate was 100% in all media. The in vitro minimal-growth conservation in low temperature ($4^{\circ}C$) was effective in the media containing with $10mg{\cdot}L^{-1}$ ABA or 6% sucrose, and the healthy plantlets could be preserved over 18 months without subculture. Especially, long-term conservation using minimal growth of S. sarmentosum was much more efficient in the medium containing high level sucrose at $4^{\circ}C$ compared to others.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.34-39
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• 2005

There are various crop diseases in green houses that are caused by the cultural environments, especially high temperature and moisture. To solve the forementioned problems, farmers are overusing agricultural chemicals, causing other damages by the chemical residue. In this study, antagonistic bacteria as biological control agents were isolated to produce the environmentally-friendly crops for use in green houses. Eighteen species of antagonistic bacteria were totally isolated from the soil and plants in the Perilla fields, and AK-17 showed the highest activity among the isolates. According to the results of anti-fungal spectrum against several pathogens by AK-17, the antagonism effect of the isolates was remarkable against grey mold rot by Botrytis cinerea, sclerotinia rot by Sclerotnia sclerotiorum, and stem rot by Rhizoctonia solini. To evaluate the biological control effects of the isolates against the major diseases of Perilla, studies were carried out to evaluate the preventive and the curative effects of the diseases throughout the pot experiments. According to the forementioned experiments, the preventive and the curative effects by the isolates against sclerotinia rot were respectively showed as 55% and 92%. For the grey mold rot, those were 40% and 78%, respectively. As to the evaluation of the growth-promoting effect by AK-17, the length and the biomass of the tested plants were increased to 120% and to 164%, respectively. For the leaf numbers and area were respectively increased to 120% and 220%. Furthermore, AK-17 was identified as Burkhoderia sp. according to the results of physiological properties and genetic methods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1815-1819
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• 2009

Based on the soft and rigid extents, tissues are mainly divided into two groups in mammals, soft tissues including heart, lung, kidney and brain, and hard tissues including tendon, cartilage, teeth and bone. Among various tissues, bone, a dynamic rigid organ, is continuously remodeled by the opposing functional activity between bone formation by osteoblasts and bone destruction by osteoclasts. Bone protects the soft tissues and provides mineral reservoirs, which can supply the mineral needs of other soft tissues to normally maintain cellular function. While calcification in bone is an important action to fundamentally support the body and protect the soft tissues, calcification in soft tissues, including the heart, aorta, kidney, lung and spleen, results in severe organ damages, eventually causing sudden death. A growing body of evidence indicates that the osteoporotic patient who are aging, post-menopausal, diabetes and chronic kidney disease simultaneously represent a high clinical incidence of soft tissue calcification, illustrating a link between soft tissue calcification and bone decalcification (osteoporosis). This study will review what is currently known about the connection between bone decalcification and soft tissue calcification.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.211-215
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• 2002

This study was carried out to find out the optimum harvesting time on the basis of physiological characteristics, yield and commercial value in four years old ginseng. For this purpose, the changes of agronomic growth characteristics of the aerial and underground parts with different growing stages were examined with fourth year ginseng. The leaf growth was dramatically increased from the mid-April (shooting stage) to the mid-May (flowering stage), and the growth was nearly completed by the mid-May, but the stem growth continued by the mid-August. The weight of fresh root decreased from the April (20.7g) to the June (18.2g), but increased from the June to the October(45. 1g). The yield of fresh root per "Kan" was 1.5 kg, 1.2kg and 1.3kg at the April, the May and the June, respectively, thereafter continually increased to 2.9 kg of the October, which showing the maximum yield. In conclusion, the ginseng root was generally harvested from the September to the October at farm-house, but it had better be harvested after the mid-October rather than from September to October considering the weight of dry root and the yield of fresh ginseng.h ginseng.