• The Korean Journal of Pesticide Science
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• v.5 no.3
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• pp.50-53
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• 2001

Severe crown gall disease was occurred in green house cultivating rose in Jinchen, Chungbuk recently. Although it causes problem on rose cultivation, the growers do not have many choices of control measures for the disease now. Agrobacterium radiobacter K84 has been known as a strong antagonist against A. tumefaciens, a pathogen causing crown gall disease, and used as a biopesticide for crown gall in many countries since it had been introduced in 1972. We tested control activity of A. radiobacter K84 for the crown gall disease on rose. Spray of A. radiobacter K84 suspension on above ground of rose either before or after pathogen spray reduced size and fresh weight of galls significantly. Size and fresh weight of galls on roses inoculated with pathogen either before A. radiobacter K84 spray (pathogen-K84 treatment) or after A. radiobacter K84 spray(K84-pathogen treatment) were 4 to 5% of those of galls on roses inoculated pathogen only. Disease incidence of plants inoculated pathogen only was 85% whereas disease incidence of pathogen-K84 or K84-pathogen treatments were 6.7% and 5.0% respectively. Dipping of roots of rose in suspension of A. radiobacter K84 was also reduced size of galls and diseased rate significantly. These results indicate that A. radiobacter K84 is effective in the prevention of gall formation by A. tumefaciens and it can be used to control of crown gall disease of rose.

• Applied Biological Chemistry
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• v.38 no.2
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• pp.123-128
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• 1995

Several factors affecting on transformation efficiency were studied to establish a Agrobacterium rhizogenes mediated system for the transformation of Populus species, and We could obtaine tansgenic plantlets expressing the introduced gene. Leaf sections were more sensitive than stem sections to kanamycin and thought to be better material for transformant screening. The bacterial density did not affect on the efficiency of transformation over the range of $4{\times}10^5{\sim}7{\times}10^9\;cfu$. The optimum period for co-cultivation was one day or shorter. Both of the optimum concentrations of cefotaxime and ampicillin in the medium were $250\;{\mu}g/ml$ for elimination of bacteria from the inoculated leaf sections. The addition of acetosyringone in the bacterial culture medium increased transformation rate, and the highest rate was obtained at $50\;{\mu}M$ of acetosyringone. The transformed galls could be selectively induced and gown on the growth regulator-free medium or on the medium containing $100\;{\mu}g/ml$ or higher contrition of kanamycin. The roots were induced from the galls incited by A. rhizogenes within 3 weeks on the growth regulator-free medium as well as on the medium containing growth regulators. The plantlets were regenerated from the galls cultured for 6 weeks on the medium containing 0.05 mg/ml of NAA and 0.5 mg/ml of BA. The expressions of the introduced opine gene in the transformed galls and plantlets were confirmed by the analysis of agropine and mannopine.

• Journal of Life Science
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• v.25 no.7
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• pp.748-756
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• 2015

The report explores the possibility that the single extract of natural substances and the mixture of single extracts of natural substances create a synergy effect to increase the antimicrobial activity. It also compares the previous researches to find out if the natural medicinal herbs’ extract has antimicrobial activity on dandruff causative organism, Malassezia furfur. For the experiment on the mixture of single extracts of natural substances, the results are like following: 1. Staphylococcus aures’s antibacterial activity is resistant to mixture of three natural substances. 2. Escherichia coil’s antibacterial activity is resistant to mixture with Coptidis rhizoma. 3. Candida albicans’ antifungal activity is resistant to mixture with Chinese galls, which means the different results may be expected when tested with each germ. 4. On the other hand, Malassezia furfur has no antifungal activity on the single extract of natural substances and shows weak antifungal activity, whose diameter is 3.20 mm when tested with the mixture of 50% of Coptidis rhizoma and 50% of Phytoncide. The result is totally different from the one on the same eumycetes, C. albicans. That is because M. furfur has more lipophilic chemicaled cell walls than C. albicans does and it also consists of lamella layer, inner plasma membrane and intermediate multiple layers.

• Proceedings of the Zoological Society Korea Conference
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• 1996.10a
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• pp.156.2-156
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• 1996

No Abstract, See Full Text

• 한국균학회소식:학술대회논문집
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• 2015.05a
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• pp.29-29
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• 2015

Clubroot disease is caused by the soil-born obligate plant pathogen Plasmodiophora brassicae. This pathogen can infect all cruciferous vegetables and oil crops, including Brassica rapa, B. oleracea, B. napus, and other Brassica species. Clubroot disease is now considered to be a major problem in Chinese cabbage production in China, Korea, and Japan. We collected several hundreds of P. brassicae infected galls from Korea, and isolated the single spore from the collection. For establishment of novel isolation, and mass-propagation methods for singe spore isolates of P. brassicae pathogen, we developed new filtration method using both cellulose nitrate filter and syringe filter. Accurate detection of P. brassicae pathogen in the field was done by using real-time PCR in the potential infested soil. When we tested the different pathogenicity on commercial Chinese cabbage varieties, P. brassicae from collected galls showed various morphological patterns about clubroot symptom on roots. To date, 8 CR loci have been identified in the B. rapa genome using the quantitative trait loci (QTL) mapping approach, with different resistant sources and isolates. We are trying to develop the molecular marker systems for detect all 8 CR resistant genes. Especially for the study on the interaction between pathogens and CR loci which are not well understood until now, genome wide association studies are doing using the sequenced inbred lines of Chinese cabbage to detect the novel CR genes.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.126-126
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• 2003

Incidence of crown gall on lower stem of chrysanthemum, Chrysanthemum morifolium Ramat., was first observed at Hwasung, Gyeonggi, Korea in 2001, Tumors on the stem were 1.5-2 cm in size and semi-round with rough surface texture of dark brown color. Four strains of bacteria isolated from the tumor tissues were characterized. Their colonies were convex, glistening, circular with an entire edge, and white to tannish-cream in color on PDA plus CaCO$_3$. They were gram negative, oxidase positive, and growing on DIM agar. The bacterial isolates inducing gall formation in chrysanthemum were identified as Agrobacterium tumefaciens based on biochemical and physiological characteristics, fatty acid profile using Sherlock Microbial Identification System, and substrate utilization patterns using Biolog Identification System. Young chrysanthemum plants inoculated with the bacteria developed typical galls within two to three weeks. Seedlings of tomato and slices of carrot roots also produced typical galls two to three weeks after inoculation. This is the first report on crown gall of chrysanthemum in Korea.

• Herbal Formula Science
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• v.12 no.1
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• pp.159-175
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• 2004

The inhibitory effects of 207 oriental medicines and 19 oriental prescriptions on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical were examined. The most effective oriental medicines were the fruit of Terminalia chebula, followed in order by the seed of Areca catechu, the heart wood of Caesalpinia sappan, the pericarp of Castanea crenata, the seed of Nelumbo nucifera, Rhus galls, the root of Sanguisorba officinalis, and the bark of Betula platyphylla at the concentration of 10 ${\mu}g$／mL. Of the 19 oriental prescriptions, Buyeonsan and Samsinhwan showed the potent scavenging activities of 88% and 71% on DPPH radical at the concentration of 5 ${\mu}g$／mL, respectively.

• Mycobiology
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• v.37 no.1
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• pp.69-71
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• 2009

Clubroot symptoms occurred severely on roots of Pak-Choi (Brassica campestris ssp. chinensis) grown in greenhouses in Gwangju city, Gyeonggi province, Korea in September, 2008. The incidence of the disease symptoms reached as high as 90% in three greenhouses investigated. The root galls collected from the greenhouses were sectioned using a scalpel and observed by light microscope. Many resting spores were found in the cells of the root gall tissues. Suspension of resting spores was prepared from the root galls and inoculated to roots of healthy Pak-Choi plants. Each of five resting spore suspensions caused clubroot symptoms on the roots, which were similar to those observed during the greenhouse survey. Resting spores of the pathogen were observed in the cells of the affected roots. The clubroot pathogen was identified as Plasmodiophora brassicae based on its morphological and pathological characteristics. This is the first report that Plasmodiophora brassicae causes clubroot of Pak-Choi.

• Research in Plant Disease
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• v.6 no.1
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• pp.23-26
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• 2000

Effects of infection time of the clubroot pathogen, Plasmodiophora brassicae, on yield loss of Spring-sown Chinese cabbage plants were examined in field experiments. Yield loss of Chinese cabbage plants increased as the infection time becomes early. Plants infected at 20 days after transplanting or earlier were completely killed before harvest, and those infected at 30 days after transplanting were healthy in appearance but their head weights were reduced to 59% with poor commodity value. The plants infected 40 days after transplanting were not affected in yield. Development of root hairs in diseased plants was greatly reduced as the infection progressed, and root length was reduced to 1/2 to 1/3 of that of healthy plants. root galls were first developed 20 days after inoculation and rapidly enlarged to reach the peak in size 20 days from initial development, and decayed thereafter. Development and decay of root galls tended to be faster at later season as air temperature became high, regardless of the infection time. Diseased plants started to wilt approximately 10 days after root gall development. Root galls began to decay 10 days after initial plant wilting, and then were completely rotten within following 10 days. Based on the results, root gall development stages on spring-sown Chinese cabbage plants could be grouped into 20 days of root gall enlargement period, and 10 days of root gall decay period, followed by survival period in soil.

• Korean journal of applied entomology
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• v.10 no.1
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• pp.23-30
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• 1971

This work was carried out to study the chemical properties, the activity of several enzymes, chemical components and the respiratory intensity of mite galls on the leaves of Lycium chinense MILL. caused by Eriophyes kuke KISHIDA. The activities of catalase and peroxidase were higher in the gall tissue, when compared to the healthy tissue, and were increased as tile gall developed. The activity of phosphorylase of the healthy tissue seemed to be higher than that of the large gall l tissue, considering the competitive inhibition of phosphomonoeoterase and $\beta-amylase$, The activities of invertase and $\beta-amylase$ were about two times higher in the large sail tissue than those of the healthy tissue. The content of the crude protein was $20\%$ higher in the small gall tissue than that of the healthy leave tissue, and decreased as the gall matured. On the other hand, the reducing sugar level was less in the small gall tissue than that of the healthy leaves, but as the gall grew, the content of reducing sugar of the gall tissue was increased. The contents of phosphorus and tannin were increased gradually as the gall matured, and their content showed about two times higher than those of the healthy. The matured gall tissue showed higher $QO_2$ than the healthy tissue. On the other hand, the matured gall tissue presented lower $QCO_2$ than the healthy tissue, and the RQ of the healthy tissue was higher than that of the gall tissue.