• Korean Journal of Medicinal Crop Science
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• v.10 no.3
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• pp.155-161
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• 2002

Using semi-selective (SS-) and selective (Jee-) medium, we identified the pathogens isolated from the symptomatic plants and soils collected from different locations, such as Suwon, Andong, and Youngju, as P. drechsleri, which is Phytophthora root rot causal agent of A. macrocephala. At $25^{\circ}C$, these isolates were grown faster on 10% V8A (V8 juice agar) medium than on PDA (potato dextrose agar) with hyphal swelling, but no growing was observed at below $5^{\circ}C$ and over $40^{\circ}C$. In order to identify the pathogenicity of each isolate, seedlings of A. macrocephala were inoculated with mycelium -zoospore suspended inoculum, which was prepared by culturing on 10% V8A medium and homogenizing in distilled water. By this method, wide ranges of pathogenicity were observed as follows; $5.0%{\sim}26.4%$ of disease severities concerning the lesion areas of the top plants and $23.5%{\sim}72.2%$ of disease incidences. Therefore, this was considered as a efficient method to identify the pathogenicity of P. drechsleri in large scale screening. P-A200073, isolated from soils in Andong, and P-9755, from the root of symptomatic plant of A. macrocephala in Suwon, showed the highest degree of pathogenicity to the seedlings. By these isolates, lesion areas and disease incidences of the inoculated seedlings were occurred $26.4%{\sim}63.2%$ and $25.1%{\sim}72.2%$, respectively. However, no symptoms were observed in uninoculated control. Same pathogens were reisolated from roots and lower stems of the inoculated plants, but not from leaves.

• Korean Journal of Organic Agriculture
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• v.21 no.2
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• pp.283-294
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• 2013

Root-rot disease is a serious problem in ginger cultivation fields and it reduces the quality and productivity of ginger. This study was conducted to investigate the effects of different soil physical and chemical properties on the changes of ginger growth. As comparing the selected soil chemical properties after harvesting the ginger plants with those before planting them, the contents of total nitrogen and exchangeable $Mg^{2+}$ increased, whereas electrical conductivity (EC) and exchangeable $K^+$ content decreased. Potassium (K) concentrations in ginger plant were markedly higher in both its shoot and root parts ranging from 63.9 to $72.3g\;kg^{-1}$ and from 27.6 to $37.3g\;kg^{-1}$, respectively, which might be related to the decrease of exchangeable $K^+$ content in soils. Incidence rate of ginger root-rot disease in the plots ranges between 26.7% and 88.1%. It was higher in low elevation plots with clay loam soils than in high elevation plots. In addition, the incidence of the disease increased as affected by high temperature and humid condition during the growth and maturity stages of ginger. Therefore, soil texture, field slop, and drainage system as well as chemical properties should be considered to cultivate ginger plant.

• International Journal of Industrial Entomology and Biomaterials
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• v.39 no.2
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• pp.82-85
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• 2019

We investigated the anti-microbial activity of propolis against the pathogenic bacteria and fungi on ginseng. We selected six microbials that caused postharvest root rots in ginseng. Propolis extracts were prepared by using the ethanol extraction method. We seeded the bacteria and fungi related to ginseng disease on a specific culture medium, and treated it with propolis extracts by using the paper disc method. Propolis extracts indicate the anti-microbial activity against Paenibacillus polymyxa, Fusarium solani, Rhizoctonia solani AG-1 and Pythium ultimum. However, the anti-fungal activity of propolis is weak on Pseudomonas fluorescens subsp. Cellulosa and Colletotrichum gloeosporioides. As a result, the antimicrobial effects of propolis against microbial that prevent ginseng growth were confirmed. The antimicrobial effects are shown according to the concentration of propolis against root rot. The fungi also showed antibacterial effects in a dose-dependent manner.

• The Plant Pathology Journal
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• v.20 no.4
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• pp.277-282
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• 2004

Amendments of a recirculating nutrient solution with potassium silicate were evaluated as a means to control Phytophthora capsici infections on pepper plant(Capsicum annuum L.). Supplying the solutions with 100 or 200 ppm of silicate significantly reduced motility, root decay, and yield losses attributed to infection of P. capsici. Treating inoculated plants with potassium silicate increased root dry weights and number of fruit, especially high-grade fruit. Results were slightly superior to non-inoculated controls. The two varieties, PBC 137 and PBC 602, responded similarly to the treatments. No significant differences were observed between the 100- and 200 ppm silicate treatments. Results were better when greenhouse conditions favored the spread of P. capsici. Silicon alone did not increase pepper yield, suggesting that it acts as a disease suppression agent rather than as a fertilizer, The phenomena by which silicon confers protection against P. capsici infection and disease development are not fully understood, but our results indicate that mechanisms other than a mechanical barrier to fungal penetration are involved.

• Journal of Applied Biological Chemistry
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• v.49 no.4
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• pp.171-175
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• 2006

Chitin compost and broth were used to suppress club root. Individual cabbage seedlings were transplanted into pots(3500 ml) containing a mixture of 3% chitin compost and 50 ml of chitin broth (T1) or the same quantity control compost and control compost broth(T2). The media in each pot was then infected with Plasmodiophora brassicae. Samples were taken at 6, 7 and 8 weeks after transplanting. The population of chitinase producing bacteria in T1 was consistently larger than that observed in T2. Chitinase activity in the T1 rhizosphere was two-fold greater than that of T2 at each time point observed. Shoot dry weight, leaf number and leaf area in T1 were enhanced 20%, 10% and 12% relative to those seen in T2, respectively. The disease index and root mortality at 8 weeks after transplanting were reduced by 50% and 25% in T1 compared to T2, respectively. Results presented in this study are strongly indicative that chitin compost and broth suppress clubroot in Chinese cabbage.

• Korean Journal of Pharmacognosy
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• v.42 no.1
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• pp.98-101
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• 2011

Acne, one of the most common skin disease, is a chronic inflammatory disease and is caused by uncertain and multiple factors. Propionibacterium acnes belongs to the human cutaneous normal flora and is a major etiologic agent of acne vulgaris. In this study, we evaluated the antibacterial effect of 19 medicinal plants. Antibacterial activity of extracts prepared from the 19 medicinal plants was investigated against bacteria related to acnes, Propionibacterium acnes. Among them, some medicinal plants inhibited the growth of the P. acnes. Minimum inhibitory concentration (MIC) of Polygonum aviculare (Herb) was 0.2 mg/ml against P. acnes. MIC of Dianthus chinensis (Aerial Part), Forsythia viridissima (Fruit), Lygodium japonicum (Spore) and Sophora flavescens (Root) were 0.4 mg/ml. Based on these results, Polygonum aviculare (Herb), Dianthus chinensis (Aerial Part), Forsythia viridissima (Fruit), Lygodium japonicum (Spore) and Sophora flavescens (Root) may be considered as a candidate for a good medicine for acne.

• The Plant Pathology Journal
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• v.16 no.3
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• pp.156-161
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• 2000

A wilt disease occurred on greenhouse-grown eggplants at Yeojoo, Korea in 1997. The wilted eggplants had leaves with gradual yellowing, interveinal necrosis, and marginal crinkling. Vascular tissues of diseased stems were discolored, turned black, and microsclerotia developed at the base of stems. The disease progressed from lower parts of the plants upward. Fungal isolates from discolored vascular tissues were initially whitish to cream color on potato-dextrose agar (PDA) plate, which later turned black due to the formation of microsclerotia. Conidiophores were erect, hyaline, verticillately branched, and had 3 or 4 phialides arising at each node. Phialides were hyaline, arranged in whorls, and measured as 17.5-32.5 x 2-3$\mu\textrm{m}$. Conidia were hyaline, ellipsoidal to sub-cylindrical, mainly one-celled, and measured as 5-8.8 x 2-4$\mu\textrm{m}$. Conidia were borne in small clusters at the tips of phialides. Microsclerotia formed on PDA plates, and consisted of globular cells that formed irregular masses of various shapes. Chlamydospores were absent. Based on these cultural and morphological characteristics, the fungus was identified as Verticillium dahliae Klebahn. Pathogenicity tests by root cutting, root dipping or soil drenching resulted in similar symptoms observed in the naturally infected eggplants. This is the first report on occurrence of Verticillium wilt of eggplant in Korea.

• Korean Journal of Digital Imaging in Medicine
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• v.13 no.2
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• pp.91-97
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• 2011

This study was conducted to know usefulness of panoramic radiography by comparing clinical evaluation and dental panoramic radiography in case of oral examination. Following results were concluded by analyzing difference between the result of Clinical evaluation and dental panoramic radiography. According to comparison the result of clinical evaluation and panoramic radiography, In Shin's research, dental caries was higher by 23.1%, periodontal disease was 31.9%, in An's research, dental caries was 24.2%. From new point of view from panoramic radiography, impacted tooth was 33.6%, Sinus abnormalities was 11.6%, periapical lesion was 5.4% in Shin's research and periapical lesion was 17.4%, 3rd molar impaction was 15.3% and retained root was 5.3% in An's research. Any kind of caries were not found in oral examination in the 66.7% of patients among patients with dental root caries in An's research. There were misdiagnose in oral examination(even side(59.5%),proximal side(59.5%), seconds caries(44.0%).

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.763-770
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• 2012

Pseudomonas fluorescens 2112, isolated in Korea as an indigenous antagonistic bacteria, can produce 2,4-diacetylphloroglucinol (2,4-DAPG) and the siderophore pyoveridin2112 for the control of phytophthora blight of red-pepper. P. fluorescens 2112 was classified into a new genotype C among the 17 genotypes of 2,4-DAPG producers, by phlD restriction fragment length polymorphism (RFLP). The colonizing ability of P. fluorescens 2112 in pea rhizosphere was equal to the well-known pea colonizers, P. fluorescens Q8r1 (genotype D) and MVP1-4 (genotype P), after 6 cycling cultivations for 18 weeks. Four tested 2,4-DAPG-producing Pseudomonas spp. could colonize with about a 96% dominance ratio against total bacteria in pea rhizosphere. The strain P. fluorescens 2112 was as good a colonizer as other Pseudomonas spp. genotypes in pea plant growth-promoting rhizobacteria.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.3
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• pp.179-183
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• 2006

Alzheimer's disease (AD) is characterised neuropathologically by the accumulation of neuritic plaques and neurofibrillary tangles as well as by cerebrovascular amyloid deposition and neuronal cell loss. Current advances have shown the apolipoproteinE-epsilon 4 (ApoE4) allele to be highly associated with late-onset familial and sporadic Alzheimer's disease (AD) in Western populations. The association of ApoE allele frequencies and dementia remains unknown in populations from many countries. We recently initiated a project to examine ApoE frequencies in non-demented healthy Koreans. Genomic DNA in hair root from a thousand persons was collected and ApoE gene type was investigated with the methods of polymerase chain reaction (PCR) and restriction fragment length polymorphism. A group of a thousand non-demented Koreans over the age of 40 years were found to be positive in 15.7% of the cases for ApoE4. AD and ApoE4 were closely related. ApoE epsilon 4 was a dangerous factor of AD and ApoE 4 allele made a contribution to the heterogenicity of AD.