• Research in Plant Disease
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• v.17 no.1
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• pp.19-24
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• 2011

It was identified as a sharp eyespot (Rhizoctonia cerealis) that the isolates from abnormal symptoms in wheat that showed yellowing leaves, necrotic spot on stem base and dead tillers. These isolates have slower growth property and fewer mycelia than Rhizoctonia solani AG-1(1A) (KACC 40106). They showed binuclear cell, same media cultural and DNA characteristics to R. cerealis. They caused same symptoms on leaves and stem base appeared in artificial inoculation test, comparing to diseased wheat fields and also affect to maturing of kernels. They have optimal growth temperature and acidity on the artificial media as $20{\sim}25^{\circ}C$ and pH 5~7, respectively. In the investigation of varietal resistance of Korean winter cereal crops to sharp eyespot, there was no resistant in wheat cultivars that all materials infected over 20% diseased ratio. 12 cultivars including 'Anbaekmil', however, considered to moderate resistance with 20 to 30% infection ratio. The others crops using in feeding, whole crop barley, oat, rye and triticale were resistant below 15% diseased degree except the rye that showed over 50% infection rate. It was the first evaluation to sharp eyespot resistance for the Korean feeding crop cultivars. Most tested Korean barley cultivars for malting and food were moderate and susceptible to the sharp eyespot. Only 3 hulled barley, 'Tapgolbori', 'Albori' and 'Seodunchalbori', showed resistance with less than 10% diseased ratio. All tested naked barley cultivars showed susceptible response to the disease.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.390-399
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• 2014

The objective of this study was to establish a processing technology for preserved leaves based on the results from the examination of the optimal period and condition for dye-absorbing treatment for Eucalyptus cinerea F. Mull. ex Benth. (silver dollar eucalyptus) being used frequently as plant material for flower design. Cut foliages of E. cinerea with uniformly matured leaves were cut into 20 cm lengths and their lower stem parts were placed in dye solution in growth chambers with different temperatures (10, 20, 30, and $40^{\circ}C$), vapor pressure deficits (VPD; 0.23, 0.70, 1.17, and 1.61 kPa), and photoperiods (0, 6, 12, 24 hours) for 3, 6, 9, and 12 days, and then dried in a room of $20^{\circ}C$ for three days. Lower temperature during preserving dye treatment reduced the changes in leaf color compared with fresh leaves and decreased ${\Delta}E$ value. Especially, high temperature increased red degree (a) and decreased yellow degree (b) due to browning. Lower VPD reduced the change in leaf color compared with fresh leaves and decreased ${\Delta}E$ value. Shorter photoperiod reduced the change in leaf color compared with fresh leaves and decreased ${\Delta}E$ value. The ${\Delta}E$ value increased with increasing absorbing duration under three environmental conditions. The flexibility of stem and leaves after dipped into preserving dye solution and dried for 3 days increased with decreasing temperature, VPD and dipping duration. Therefore, the optimal environment condition for dye treatment was 0.23-0.70 kPa VPD at $10-20^{\circ}C$ in the darkness, and the optimal and economical duration was 3 days. These conditions reduced the speed of water loss by decreasing transpiration, so yellowing or browning by rapid water loss deteriorated the quality of preserved leaves out of these ranges.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.217-223
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• 2011

This study was conducted to examine the effect of several pretreatments and holding solutions on the vase life and quality of cut Polygonatum odoratum var. pluriflorum for. variegatum stems native to Korea. Postharvest foliar spray of 200 $mg{\cdot}L^{-1}$ $GA_3$ or 200 $mg{\cdot}L^{-1}$ BA + 200 $mg{\cdot}L^{-1}$ $GA_3$ markedly extended the vase life of cut stems of Polygonatum odoratum var. pluriflorum for. variegatum. These treatments maintained high chlorophyll contents as compared with the control (distilled water) during senescence of cut stems. Postharvest pretreatment (dipping) with 100 $mg{\cdot}L^{-1}$ $GA_3$ or 3% sucrose + 200 $mg{\cdot}L^{-1}$ 8-hydroxyquinoline sulfate (HQS) + 100 $mg{\cdot}L^{-1}$ $GA_3$ for 16 hours extended vase life of cut stems 2.5 times as long as nontreated control. Holding solution of 2% sucrose + 200 $mg{\cdot}L^{-1}$ HQS + 100 $mg{\cdot}L^{-1}$ $GA_3$ significantly extended vase life by 3.5 times and increased fresh weight as compared with control. $GA_3$ were very effective on preventing leaf yellowing of cut Polygonatum odoratum var. pluriflorum for. variegatum stems. Postharvest foliar spray of 200 $mg{\cdot}L^{-1}$ $GA_3$ or holding solution of 2% sucrose + 200 $mg{\cdot}L^{-1}$ HQS + 100 $mg{\cdot}L^{-1}$ $GA_3$ markedly extended vase life and improved quality of cut stems of Polygonatum odoratum var. pluriflorum for. variegatum.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.392-399
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• 2012

This study was carried out to investigate the influence of molybden (Mo) concentrations in fertilizer solution on the growth of and nutrient uptake by domestically bred strawberries. Tissue analysis based on the dry weight was also conducted to determine the threshold levels in plants when Mo toxicity developed in strawberries. The leaf chlorophyll contents decreased lineally as Mo concentrations in the fertilizer solution were elevated. The differences among treatments in chlorophyll contents were statistically significant. The fresh and dry weights decreased significantly when the Mo concentrations in fertilizer solution were higher than 3.0 mM in 'Keumhyang' and 'Maehyang' strawberries and 1.0 mM in 'Seolhyang' strawberry. The elevation of Mo concentrations in fertilizer solution resulted in severe toxicity and crops developed the unique symptoms. The margin of older leaves became yellow and desiccated. Then, the margin of leaf blade rapidly became bronze colored and died as the symptoms spread up the plants. The interveinal area of the young leaves became yellowing. The elevation of Mo concentrations in fertilizer solution did not influence the tissue P, K, and Mg contents based on the dry weight. The tissue Ca contents were higher in 1.0 mM treatment than other treatments of 'Keumhyang' and 'Seolhyang' strawberries. The tissue Mo contents based on the dry weight of 'Keumhyang', 'Maehyang', and 'Seolyahng' strawberries were 76.5, 104.0, and 187.3 $mg{\cdot}kg^{-1}$, respectively, in the 0.25 mM treatments and 4,155, 5,367, and 2,190 $mg{\cdot}kg^{-1}$, respectively, in the 4.0 mM treatments. The contents increased lineally as Mo concentrations in fertilizer solution were elevated. When the concentration of Mo at which growth of crops were retarded by 10% is regarded as threshold level, the Mo contents based on dry weight of above ground plant tissue should be lower than 653.4, 686.2, and 589.7 $mg{\cdot}kg^{-1}$, in 'Keumhyang', 'Maehyang', and 'Seolyahng' strawberries, respectively.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.743-749
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• 2010

Objective of this research was to investigate the effect of various potassium concentrations in fertilizer solution on growth of and nutrient uptake by 'Chugyang' eggplant ($Solanum$ $melongena$ L.). Tissue analyses were conducted to determine the threshold levels of potassium in plants when disorders develop for potassium. The lower leaves of K deficient plants became spotted, yellowing in color, and finally necrosis occurred. The necrosis spread inward and upward. K toxic plants developed necrotic spot at the margin of old leaves and the surface of old leaves were twisted. The tissue K contents in the most recently fully expanded leaves and dry weight of full above ground plant tissue at 35 days after transplanting showed linear and quadratic response to elevated K concentrations with the equation of y=1.127+0.3147x ($R^2$=0.8916) and y=14.92+2.2743x-$0.1402x_2$ ($R^2$=0.8659). When 10% reduction in dry weight set to threshold levels, optimum tissue K contents are in the range from 2.1 to 5.1%. The yield through 150 days after transplanting and tissue K contents at 150 days after transplanting also showed quadratic and linear responses to elevated potassium concentrations in fertigation solution with the equation of y=153.24+345.5x-$18.46x^2$ ($R^2$=0.8620) and y=0.9921+0.3860x ($R^2$=0.9611), respectively. When the 10% reduction in yield is set to threshold levels, the tissue K contents for maximum yield should be around 3.4% to 5.9% in most recently fully expanded leaves.

• Korean Journal of Environment and Ecology
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• v.24 no.1
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• pp.62-68
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• 2010

This study was conducted to find out how the germination, phenology and leaf morphology of Phytolacca insularis(endemic species of Korea) and P. americana(alien species) react to the global warming situation. Seed and seedlings of two species were sampled and placed under two separate conditions for the experiment. One of the seed and seedlings was treated in the glass house with control(ambient $CO_2$+ambient temperature, (AC-AT), and the other with control(elevated $CO_2$+ elevated temperature, EC-ET), over the period of one year, 2008-2009. The germination rate of two species was fast, and the time of their germination started early, when they were treated at EC-ET than at AC-AT. Furthermore, the germination rate of Phytolacca insularis(endemic species of Korea) was found to be comparatively lower than that of P. americana(alien species). The former showed only vegetative growth whereas the latter showed both vegetative growth and reproductive growth in one year period. The more $CO_2$ degree and temperature increased, phenological responses of two species, including leaf growth, the formation of flower stems, flowering, and fruit maturing, became much faster, and the time of their leaf-yellowing was delayed. The lamina length of P. insularis was not significantly affected by elevated $CO_2$ and temperature. The lamina length of P. americana, on the other hand, became longer at EC-ET than at AC-AT, but the leaf width of both species increased at EC-ET. As for the number of leaves, both species showed no difference. Finally, the ratio of the leaf area of P. insularis was high at AC-AT, but P. americana was high at EC-ET. These results indicate that P. americana, aliens species, reacts more sensitively to global warming than P. insularis, endemic species, does.

• Korean Journal of Plant Resources
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• v.25 no.1
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• pp.156-168
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• 2012

Chrysanthemum is a cut flower species that normally lasts for 1 to 2 weeks, in some cases 3-4 weeks. This has been attributed to low ethylene production during senescence. Reduction in cut flower quality has been attributed to the formation of air embolisms that partially or completely blocks the water transport from the vase solution to the rest of the cut flower stem, increasing hydraulic resistance which may cause severe water stress, yellowing, wilting of leaf, and chlorophyll degradation. Standard type chrysanthemum can be harvested when buds were still tightly closed and then fully opened with the simple bud-opening solution. Standard type chrysanthemum can also be harvested when the minimum size of the inflorescence is about 5-6 cm bud which opened into the first flower full-sized flower. While spray varieties can be harvested when 2-4 most mature flowers have opened (40% opening). Cut flowers are sorted by stem length, weight, condition, and so on. Standard chrysanthemum is 80 cm length for standard type and 70cm for spray type. Pre-treatment with a STS, plant regulator such as GA, BA, 1-MCP, chrysal, germicide, and sucrose, significantly improved the vase life and quality of cut flowers. It is well established that vase solutions containing sugar can improve the vase life of cut chrysanthemum. Chrysanthemum is normally packed in standard horizontal fiberboard boxes. Chrysanthemum should normally be stored at $5{\sim}7^{\circ}C$. Precooling resulted in reduction in respiration, decomposition, and transpiration activities as well as decoloration retardation. There was significant difference between "wet" storage in 3 weeks and "dry" storage in 2 weeks. In separate pulsing solution trials, various germicides were tested, as well as PGRs to maintain the green color of leaves and turgidity. Prolonging vase life was attained with the application of optimal solution such as HQS, $AgNO_3$, GA, BA and sucrose. This also retarded senescence in leaves of cut flower stems. Fresh cut chrysanthemum can be transported using a refrigerated van with $5{\sim}7^{\circ}C$. Increasing consumption and usage of cut chrysanthemum of various cultivars would require efficient transport system, and effective information exchange among producer, wholesaler, and consumer.

• Journal of Conservation Science
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• v.31 no.1
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• pp.21-27
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• 2015

The Phoenix-shaped Glass Ewer, which is No. 193 National Treasure, was seriously damaged by a unique form of green glass pieces when excavated among a number of burial accessories of Hwangnamdaechong known to have been formed in the 5th century. While it has long been exhibited at the National Museum of Korea since its treatment for conservation treatment at conservation science laboratory in 1984, the existing adhesive materials seriously deteriorated for the 30 years, and the condition was quite unstable. The epoxy resin used as a restorative materials turned yellowing due to the light and heat so much that it was no longer able to exhibit it in a stable and effective manner. As a result, a re-treatment for conservation was conducted lately. This study focuses on the three pieces of Gold wires used to carefully wrap up the handle of the Phoenix-shaped Glass Ewer broken into three pieces, which has not been studied so far. As for the analysis method for Gold wires, SEM-EDS and Stereo Microscope were used for nondestructive analysis. First of all, the result of the SEM-EDS analysis shows that the composition was Au 91.9 wt.%-Au 92.8 w.t% and Ag 5.9 wt.%-Ag 6.5 wt.%, which indicates that it was an alloy made of Au and Ag. The production technique of Gold wires was also observed by means of optical microscopes. In general, Gold wires were manufactured by a drawing process in which a lump of gold was beaten or pulled out of a hole or by a process of twisting a gold plate. However, Gold wires separated from the handle of the Phoenix-shaped Glass Ewer did not involve any trace of twisting on the surface. Rather, fine vertical stripes were observed with the sections filled up. Hence, it is thought that this Ewer went through a drawing process and then was mended. As a result, no certain relation with the golden mending material used for the Phoenix-shaped Glass Ewer was verified. The findings above indicate that most of the existing researches on Gold wires recognized them, not as separate remains, but merely as a component of other golden remains. Thus, there has been little systematic study on the manufacturing techniques of Gold wires. The future study on Gold wires may verify the correlation between the Gold wires used to fix the handle of the Phoenix-shaped Glass Ewer, which is examined in this study, with that of golden remains in the Silla era.

• Journal of Korean Society of Forest Science
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• v.47 no.1
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• pp.1-15
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• 1980

The occurrence of witches' broom of Rhus javanica was first noticed in Korea by the author in 1979. Subsequently, studies were made on the symptomatology, etiology, and transmission of the disease, as well as the effect of some antibiotics on the disease development. The results of these studies are summarized as follows: 1. Symptoms of the infected plant were characterized by dwarfing of the tree accompanied by yellowing and brooming of the foliage. 2. Electron microscopy of witches' broom diseased Rhus javanica plant revealed the occurrence of numerous mycoplasma-like organisms (MLO's) in the phloem tissue cells (sieve tube elements and phloem parenchyma cells) of the rachis and midribs of infected leaves. 3. The MLO's were bounded by a single unit membrane and contained ribosome-like granules and strands presumed to be DNA. It also appears that the MLO multiply possibly by budding as well as binary and plurinary fission. 4. In the midrib of healthy leaves, vascular bundles were collaterally discontinuous. In the diseased leaves, however, xylems were connected to each other and phloem cells showed an atrophy. Granules, which were prominent in the normal abaxial epidermis, were not observed in the peidermis of diseased leaves. 5. Electron microscopy revealed crystals or osmopholic granules in the phloem parenchyma cells, and that normal stacks of grana were not developed in the chloroplasts of infected levels. 6. The disease was experimentally transmitted by grafting. Budding was more effective than crown grafting for transmitting the disease. The disease has been transmitted by grafting even when complete union of stocks and scions has not taken place. The disease agent was not transmitted by sap inoculation. Insect transmission has not been confirmed. 7. Dipping the roots of infected plants into the 500 ppm and 1,000 solutions of either tetracycline HCI or oxytetracycline, HCI was more effective on temporary remision of the symptoms than spraying the 100 ppm and 200 ppm solutions of the same antibiotics. A greater effect was achieved through dipping into 1,000 ppm than into 500 ppm.

• Journal of Korean Society of Forest Science
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• v.78 no.2
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• pp.103-118
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• 1989

The occurrence of witches' broom in Ligustrum ovalifolium was first noticed in Korea by author in 1984. The present study was carried out with particular emphasis on the symptomatology, etiology, transmission of the disease and antibiotic treatments. The infected tissue was observed by the fluorescence and electron microscopy and its biochemical characteristics were compared with healthy one by electrophoresis. The results are summarized as follows : 1. symptoms of the infected trees were characterized by the dwarfing of the organs, yellowing and brooming of the foliage. 2. The observation by the trans electron microscopy on the witches' broom of L. ovalifolium revealed the occurrence of numerous mycoplasma-like organisms(MLOs) in the phloem tissue cells of the midribs of infected leaves. 3. The MLOs were surrounded by a single unit membrane, and they appeared to be multiplied by binary fission. 4. The presence of crystals unidentified in the phloem parenchyma cells was noticed by electron rnicroscopy, 5. The disease was able to be transmitted by budding, crown, and greenwood graftings to L. ovalifolium, L. obtusifolium, L, japonicum and also transmitted, even when the stocks and scions were not completely grafted. 6. Insect transmission on L. ovalifolium and L, obtzrsifolium was carried by Hishimonus sellatus. 7. The infected roots dipped in the 1,000 ppm of teracyclin solution was only temporarily effective in controlling the disease. 8. Infected plant with MLOs showed specific fluorescent reactions in phloems with DAPI stain. 9. The protein and peroxidase separated by electrophoresis showed strikingly distinctive difference between the healthy and diseased leaves.