• Research in Plant Disease
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• v.20 no.4
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• pp.270-274
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• 2014

Division of Forest Diseases & Insect Pests, Korea Forest Research Institute, Seoul 130-712, Korea The objective of this study was to evaluate the virulence of geographically different isolates of oak wilt pathogen, Raffaelea quercus-mongolicae and other Raffaelea species. In this study, mature trees of Quercus mongolica were inoculated with the various isolates of Raffaelea spp. and their virulence was evaluated by measuring the extent of sapwood discoloration resulting from the inoculation. The average length of discolored sapwood in a lateral direction was longest in the trees inoculated with the isolates from Korea (8.69 cm) followed by R. quercivora (7.51 cm) and the other Raffaelea spp. (3.35 cm). The lateral length of discolored sapwood caused by the inoculation with Korean strains varied from 4.71 to 14.90 cm indicating their differences in virulence. The area of discolored sapwood caused by the inoculation with Raffaelea spp. varied from 1.57 to $8.42cm^2$ indicating their differences in virulence. Based on the length and area of the discolored sapwoods, isolated YY and wj43 appeared to have the highest virulence among all the Raffaelea isolates tested. Each of the two isolates was obtained from Gangwon Province and Jeonbuk Province, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.910-914
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• 2005

This study was to determine the inhibitory effect of ethanol extract of leaf, bark and xylem of Quercus aliena Blume and, consecutively, of organic solvent subfractions against food borne pathogens. The ethanol extracts of leaf, bark and xylem of Quercus aliena Blume were shown to have antimicrobial effect against Gram-positive and Gram-negative bacteria. Listeria monocytogenes and Salmonella Typhimurium were more resistant to ethanol extracts of the Quercus aliena Blume tissues compared with Bacillus cereus and Escherichia coli O157:H7. The ethanol extract of Quercus aliena Blume leaf showed the strongest antimicrobial activity against food borne pathogens, followed by those of xylem and bark. The ethanol extract treatment $(500\~1,000\mu g/mL)$ of Quercus aliena Blume leaf completely reduced the growth of B. cereus and L. monocytogenes within 24 hour whereas $2,000\mu g/mL$ of ethanol extract was needed for complete growth inhibition of E. coli O157:H7 and S. Typhimurium. Among organic solvent subfractions obtained from the ethanol extract of leaf, bark and xylem of Quercus aliena Blume, the ethyl acetate fraction showed the strongest antimicrobial activity, but no antimicrobial activity was observed in chloroform, hexane and water fractions.

• Korean journal of applied entomology
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• v.61 no.3
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• pp.475-479
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• 2022

In this study, Periphyllus acerihabitans Zhang, 1982 is reported for the first time in Korea. Species distribution, measurement, host plants, description, key to Korean species of the genus Periphyllus, and illustrations of diagnostic characters for apterous viviparous females are provided.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1061-1063
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• 2010

본 연구는 2008년 1월 1일부터 12월 31일 까지 1년 동안 대전에 위치한 일개 대학병원 퇴원요약 정보를 활용하여 환자 개인요인 측면과 의료적 측면에서 전원 환자의 특성과 요인을 파악하여 전원환자 관리의 자료로 이용하고자 한다. 연구결과 퇴원환자 30,793명중 타 병원으로 전원 된 990명 전체가 대상이었으며, 성별로 보면 남자가 여자보다 높은 분포를 보였다. CART기법에 의한 의사결정나무는 치료결과, 입원경로 등이 타 의료 기관으로 전원되는 특성을 보여주고 있음을 알 수 있다. 결과적으로 의료적인 측면보다는 개인적인 측면으로 환자들이 전원을 하는 비율이 높았다. 이와 같이 전원환자 특성 및 요인 분석이 병원의 지속적인 환자 관리와 환자와의 신뢰를 형성하고 꾸준한 병원방문을 유도할 수 있을 것으로 생각된다.

• Research in Plant Disease
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• v.12 no.3
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• pp.189-196
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• 2006

Crown gall on lower stem of weeping fig(Ficus benjamina Roxb.) was first observed at Daejon in 2003. Tumors were about 15 cm in size and semi-round with rough surface texture of dark brown color. Two virulent isolates among ten bacteria isolated from the tumor tissues were characterized. Their colonies were convex, glistening, circular with an entire edge, and white or tannish cream in color on potato dextrose agar supplemented with 0.5% $CaCO_3$. They were rod shape with peritrichous flagellae, gram-negative, aerobic growth, oxidase-positive, and grew on D1M agar. The isolates were identified as Agrobacterium larrymoorei and A. tumefaciens based on biochemical and physiological characteristics, fatty acid profiles and substrate utilization patterns. Seedlings of some host plants excepting grapevine produced typical galls two to three weeks after inoculation with cell suspensions of the virulent strains. This is the first report on crown gall of weeping fig in Korea.

• Journal of Korean Society of Forest Science
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• v.62 no.1
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• pp.76-81
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• 1983

Pedicularis spp. are the alternate hosts of the white pine blister rust fungi in the forests of Korea, and Ribes spp. were found as other alternate hosts by artificial inoculation test. New biotypes (races) with different host selectivity and pathogenicity of the causal fungi were speculated at various places in Korea. The aeciospores of the fungi were collected from two isolated places, Pyeongchang and Namwoen, and artificially inoculated on Pedicularis resupinata and six species of the genus Ribes. Among the tested alternate host species, P. resupinata and R. montigenum were only susceptible to both the Pyeongchang population and the Namwoen population, showing similar pathogencity between the two fungai populations. Three white pine species were planted in fungus-infested stands to study the susceptibility of each tree species. Four years later, 17.7% of Pinus koraiensis and 26.3% of the P. strobus were infected, but P. parviflora was free from attack. From the above results, it was concluded that the white pine blister rust fungus populations in Korea are of the same biotype, with P. koraiensis and P. strobus as aecial hosts, and Pedicularis spp. and Ribes spp. as telial hosts.

• Research in Plant Disease
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• v.15 no.3
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• pp.259-261
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• 2009

Sclerotinia shoot rot of Grapevine(Vitis labruscana) occurred at Gapyeong and Yeongwol area from 2003 to 2005. Infected plants showed shoot blight at the one-year-old fruit bearing branches. The first visible symptom noticed was wilting and blighting of the branches. The obvious and typical initial symptom is the presence of a cottony, white, dense mat of mycelial growth on the surface of the diseased lesions. The base or stem of the infected young shoots develop a pale brown rotted area, which girdled and killed shoots. In advanced stages of the disease, stems and branches became bleached and eventually died. The isolates collected from diseased grapevine stem were identified as Sclerotinia sclerotiorum based on the morphological and cultural characteristics. The pathogenicity test revealed that Vitis vinifera(cultivar: Kyoho) was stronger than V. labruscana(cultivar: Campbell early) to the pathogen. This is the first report on sclerotinia shoot rot of grapevine in Korea.

• Korean journal of applied entomology
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• v.30 no.4
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• pp.227-232
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• 1991

The pathogenicity of entomopathogenic nematodes Sfeinernema earpocapsae and Heferorhabditis baeferiophora was evaluated against forest insect pests, alder leaf beetle Agelastiea eoerulea, pellucid zygaenid Pryeria siniea, and box-tree pyralid Glyphodes perspeetalis. Alder leaf beetle larvae were exposed to S. earpocapsae at concentration of 0, 25, 50, and 100 nematodes and to H. baeferiophora at concentration of 0, 10, 20, and 40 nematodes per larva on alder leaves. Mortalities of 1st instar lavae were 85.4 $\pm$ 4.1-100%, 2nd instar larvae 80.0 $\pm$ 5.8-100%, and 3rd instar larvae 65.0 $\pm$ 10.8-100% in S. earpocapsae and those of 1st instar larvae were 82.5 $\pm$ 6.9-100%, 2nd instar larvae 77.5 $\pm$ 4.7-100%, and 3rd instar larvae 55.0 $\pm$ 13.5-100% in H. baeferiophora treatment. When pellucid zygaenid larvae were exposed to S. earpocapsae at concentration of 0, 5, 10, 20, 40, and 80 nematodes and to H. baeteriophora at concentration of 0, 2, 5, 10,20, and 40 nematodes per larva, mortalities were 98.9 $\pm$ 1.1-100% in S. earpocapsae and 26.7 $\pm$ 5.1-74.5 $\pm$ 6.2% in H. baeferiophora. The mortalities of box-tree pyralid larvae were 97.8 $\pm$ 1.5-100% in S. earpocapsae treated with concentration of 0,20,40, and 80 nematodes per larva and those were 92.0 $\pm$ 6.2-98.9 $\pm$ 1.1 % in H. baeferiophora treated with con'||'&'||'not;centration of 0, 10, 20, and 40 nematodes per larva.

• Journal of Life Science
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• v.32 no.1
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• pp.56-62
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• 2022

This study was investigated to evaluate the potential of Stewartia koreana Nakai as an oral healthcare material. The inhibitory effects of extracts on the biofilm formation and fimbriae genes expression of Porphyromonas gingivalis were determined by minimal inhibitory concentrations (MIC), biofilm biomass staining, SEM, and qRT-PCR analysis. The S. koreana Nakai branch was extracted into 70% ethanol, and bacteriostatic MIC of extracts against P. gingivalis were 0.6 mg/ml. In P. gingivalis cultures treated with 0.2-2.0 mg/ml of extract, biofilm production rate was significantly decreased in a concentration-dependent manner. The morphology of treated and untreated samples was observed by SEM, and cell aggregation and biofilm were only observed in those treated with extract. Subsequently, qRT-PCR analysis showed that the mRNA expression on fimbriae genes fimA and fimB was suppressed in a concentration-dependent manner. Based on these results, it can be suggested that S. koreana branch extract has the potential to be used as naturally derived oral healthcare material because of its bacteriostatic action and inhibition of P. gingivalis biofilm formation.

• Korean Chemical Engineering Research
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• v.54 no.6
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• pp.762-766
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• 2016

In this study, natural extract including Phellodendro namurense, Eucommia ulmides Oliv and Prunus padus were tested for antimicrobial activity and safety. Antimicrobial activity was measured by using opportunistic microbes such as Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. As safety test, cell viability test, single dose oral toxicity test, single dose inhalation toxicity test, repeat dose inhalation toxicity test and eye irritation test were done. From antimicrobial test, natural extract showed execellent antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Escherichia coli. From 5 kinds of safety tests, toxicity was not observed. From experimental results, natural extract including Phellodendro namurense, Eucommia ulmides Oliv and Prunus padus showed superb safety and antimicrobial effect.