• Korean journal of applied entomology
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• v.43 no.4 s.137
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• pp.329-332
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• 2004

This experiment was conducted to investigate pathogenicity of Spodoptera exigua nucleopolyhedrovirus (SeNPV) with different temperatures for mass production. In laboratory condition, $LC_{50}$ values of SeNPV were $9.797{\times}10^{3}PIBs/mL$ at $20^{\circ}C$ and $3.351{\times}10^{2}PIBs/mL$ at $32^{\circ}C$ in 2nd instar larvae. $LC_{50}$ of the other larval stage were similar to that of 2nd instar. $LT_{50}$ values of SeNPV was 9.0 days in $1.0{\times}10^{3}PIBs/mL$ but 6.9 to 3.5 days in $1.0{\times}10^{4-6}PIBs/mL$ against 3rd instar of Spodoptera exigua. $LT_{50}$ Values of $1.0{\times}10^{4}PIBs/mL$ were 5.7, 5.5 and 4.9 days in 24, 28 and $32^{\circ}C$, respectively. As a results, $LT_{50}$ was shortened with increase of temperatures up to $32^{\circ}C$ and also dependent on viral concentration and larval instars.

• Journal of Plant Biotechnology
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• v.6 no.4
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• pp.229-233
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• 2004

Partial desiccation of embryogenic calli cultures or somatic embryos leads to different physiological changes and maturation of somatic embryos, leading to improved plant regeneration. Embryogenic calli was induced from immature inflorescence segments and young leaf rolls of sugarcane (Saccharum officinarum hybrids CoC-671) on Murashige and Skoog's basal medium enriched with different concentrations of 2,4-D ($1-4\;\cal{mg/l}$), L-glutamine ($100\cal{mg/l}$), malt extract ($100\cal{mg/l}$), casein hydrolysate ($1000\;\cal{mg/l}$) and coconut milk ($5\%$) and solidified with $0.2\%$ gel rite. The embryogenic calli were subjected to desiccation for 1-8 h. Desiccation of the calli for 6-7 h resulted in enhancement of plant regeneration frequency ($83-96\%$) as compared to control ($12\%$). Plantlets exhibited vigorous growth to maturity in the greenhouse. Partial desiccation of embryogenic calli offers as a simple method for improving plant regeneration frequency in sugarcane.

• Journal of Plant Biotechnology
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• v.4 no.3
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• pp.117-122
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• 2002

Cotton Glutathione S-Transferase(GST: EC 2.5.1.18) was cloned and Gh-5 cDNA was overexpressed in tobacco (Nicotiana tabacum) plants. The transformation of cotton GST in tobacco plant was confirmed by northern blot analysis. Type I and Type II transcript patterns were identified in Gh-5 transgenic tobacco plants. Type I transcripts was only discussed in this paper. Glutathione and 1-chloro-2,4-dinitrobenzene (CDNB) were used as the substrates, and the activity of GST in the type I transgenic plants was about 2.5-fold higher than the non-expressers and wild type tobacco plants. The expression of cotton GST in tobacco plants proved that Gh-5 could be translated into functional protein. Type I transgenic plants produced functional GST in the cells. Type I showed higher GST specific activity than Type II in the transgenic plants. Control and transgenic seedlings were grown in the growth chamber and under the light at 15$^{\circ}C$, and the effects of cotton GST in the seedlings was evaluated. The growth rate of Gh-5 overexpressors was better than the control and non-transgenic tobacco plants. Salinity tolerance was also analyzed on the seeds of transgenic plants. Seeds of Gh-5 overexpressors and the wild type tobacco seedlings were germinated and grown at 0, 50, 100, 150, and 200 mM NaCl solution. Gh-5 transgenic seedlings showed higher growth rate over control seedlings at both 50 and 100 mM NaCl solution. But at 0, 150, and 200 mM NaCl concentration, the difference in growth rate was not detected.

• Mycobiology
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• v.40 no.4
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• pp.244-251
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• 2012

In vitro and greenhouse screening of seven rhizobacterial isolates, AB05, AB10, AB11, AB12, AB14, AB15 and AB17, was conducted to investigate the plant growth promoting activities and inhibition against anthracnose caused by Colletotrichum acutatum in pepper. According to identification based on 16S rDNA sequencing, the majority of the isolates are members of Bacillus and a single isolate belongs to the genus Paenibacillus. All seven bacterial isolates were capable of inhibiting C. acutatum to various degrees. The results primarily showed that antibiotic substances produced by the selected bacteria were effective and resulted in strong antifungal activity against the fungi. However, isolate AB15 was the most effective bacterial strain, with the potential to suppress more than 50% mycelial growth of C. acutatum in vitro. Moreover, antibiotics from Paenibacillus polymyxa (AB15) and volatile compounds from Bacillus subtilis (AB14) exerted efficient antagonistic activity against the pathogens in a dual culture assay. In vivo suppression activity of selected bacteria was also analyzed in a greenhouse with the reference to their prominent in vitro antagonism efficacy. Induced systemic resistance in pepper against C. acutatum was also observed under greenhouse conditions. Where, isolate AB15 was found to be the most effective bacterial strain at suppressing pepper anthracnose under greenhouse conditions. Moreover, four isolates, AB10, AB12, AB15, and AB17, were identified as the most effective growth promoting bacteria under greenhouse conditions, with AB17 inducing the greatest enhancement of pepper growth.

• Korean Journal of Plant Taxonomy
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• v.38 no.4
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• pp.539-545
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• 2008

Distribution of Carex miyabei Franch., formerly considered as an endemic species of Japan, in Korea is verified and reported here. It is distinguished from the morphologically similar species in the same section, such as C. lasiocarpa Ehrh. var. occultans (Franch.) $K{\ddot{u}}k.$, C. drymopila Turcz. ex Steud. var. abbreviata ($K{\ddot{u}}k.$) Ohwi, and C. glabrescens (Kük.) Ohwi, in having long-beaked and acutely 2-toothed perigynia which are densely covered with stout short hairs.

• Korean Journal Plant Pathology
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• v.3 no.4
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• pp.261-269
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• 1987

A virus which induced yellowing, vein banding and ruffling on pepper in the field was investigated. The virus reacted strongly with PVY - antiserum in ELISA, but not with antisera of cucumber mosaic virus, tobacco mosaic virus, tomato black ring virus, alfalfa mosaic virus, tomato spotted wilt virus, tobacco etch virus, pepper mottle virus, and tobacco ringspot virus. Electron micrographs revealed that the virus was a flexuous rod of 750-760nm in length. The virus was transmitted mechanically and by Myzus persicae in a nonpersistent manner. The host range was similar to that of PVY, except that Chenopodium amaranticolor and C. quinoa were infected systemiclly.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.4
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• pp.365-372
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• 2006

A dynamic compartment model is presented to predict the contamination level of agricultural plant by $^{137}C_s$ as a result of a soil deposition. The model considered the processes of a percolation, soil mixing by a plowing before transplanting, plant uptake, leaching to a deep soil, and fixation to a clay mineral. The effects of the soil properties (pH, clay mineral, organic matter content, and exchangeable K), which are spatially varied, on a plant uptake and the leaching rates of $^{137}C_s$ in a root zone soil were modeled by the Absalom model. To test the validity of the model, the $^{137}C_s$ aggregated transfer factors(TFa) for rice plants were compared with those observed from some simulated $^{137}C_s$ soil deposition experiments, which were carried out with respect to rice plants cultivated in seventeen paddy soils of different properties for two consecutive years. Observed $^{137}C_s$ TFa values of the rice plants did not show an evident trend for the pH and clay content of the soil properties, while they increased with an increasing organic matter content or a decreasing exchangeable K concentration. Predicted $^{137}C_s$ TFa values of the rice plants were found to be comparable with those observed.

• Journal of Korean Society of Water and Wastewater
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• v.8 no.3
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• pp.9-18
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• 1994

Activated sludge pilot plant testing was conducted to determine the ability of a well-designed activated sludge treatment system to remove chromic toxicity from the bleached kraft pulp mill effluent. Removals of conventional(BOD and SS) and nonconventional(resin and fatty acids, color, AOX) pollutants were estimated. The pilot plant was operated at steady state for about 10 weeks at an F/M of 0.28 and a sludge age of 8.4 days. The average MLSS concentration was 4,309mg/l, of which volatile fraction was 57%. During the operation period, the BOD removal reaction rate(k) was determined to be 8.2/day at $30^{\circ}C$. The BOD removal was 84 percent, which was 3 to 6 percent lower than expected for full-scale treatment. The chronic toxicity of the activated sludge effluent was tested by employing both Dinnel and the BML protocols. It was found that the pilot plant could achieve in excess of 90 percent reduction in chronic echinoderm toxicity. The data show slight reduction of color and AOX across the activated sludge system. The pilot system, however, demonstrated on excellent removal of resin and fatty acids.

• Mycobiology
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• v.40 no.1
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• pp.59-65
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• 2012

Antagonistic microorganisms against $Rhizoctonia$ $solani$ were isolated and their antifungal activities were investigated. Two hundred sixteen bacterial isolates were isolated from various soil samples and 19 isolates were found to antagonize the selected plant pathogenic fungi with varying degrees. Among them, isolate C9 was selected as an antagonistic microorganism with potential for use in further studies. Treatment with the selected isolate C9 resulted in significantly reduced incidence of stem-segment colonization by $R.$ $solani$ AG2-2(IV) in Zoysia grass and enhanced growth of grass. Through its biochemical, physiological, and 16S rDNA characteristics, the selected bacterium was identified as $Bacillus$ $subtilis$ subsp. $subtilis$. Mannitol (1%) and soytone (1%) were found to be the best carbon and nitrogen sources, respectively, for use in antibiotic production. An antibiotic compound, designated as DG4, was separated and purified from ethyl acetate extract of the culture broth of isolate C9. On the basis of spectral data, including proton nuclear magneric resonance ($^1H$ NMR), carbon nuclear magneric resonance ($^{13}C$ NMR), and mass analyses, its chemical structure was established as a stereoisomer of acetylbutanediol. Application of the ethyl acetate extract of isolate C9 to several plant pathogens resulted in dose-dependent inhibition. Treatment with the purified compound (an isomer of acetylbuanediol) resulted in significantly inhibited growth of tested pathogens. The cell free culture supernatant of isolate C9 showed a chitinase effect on chitin medium. Results from the present study demonstrated the significant potential of the purified compound from isolate C9 for use as a biocontrol agent as well as a plant growth promoter with the ability to trigger induced systemic resistance of plants.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.540-544
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• 2010

The nursery plant quality and flower bud induction of new strawberry cultivars, 'Maehyang' and 'Seolhyang' in forcing culture were evaluated in the highland and lowland region. In order to produce daughter plants, the new cultivars were grown in the open field located at both highland (Daekwallyung, above 800 m sea level) and lowland (Gangneung, above 20 m sea level) region, respectively. The average air temperature at highland during nursery plant propagation period was $5.3^{\circ}C$ lower than those at lowland. The number of daughter plants produced at lowland was 2 times as high as those of highland, presumably due to the higher air temperature. Anthracnose incidence rates of runner plants produced at lowland were 4 to 7% as high as those in highland. Mean temperature in the highland ($23.5^{\circ}C$) during flower bud differentiation treatment was $5.1^{\circ}C$ lower than that in the lowland ($28.6^{\circ}C$). Seedlings produced in highland showed higher C/N ratio and lower T/R ratio compared to those produced in lowland. The average flower bud formation date of the daughter plants grown in highland were advanced by 30 days compared to the date in lowland. Accordingly, highland was supposed to be appropriate region for raising seedlings in forcing culture of the new strawberry cultivars of 'Maehyang' and 'Seolhyang'.