• 제목/요약/키워드: Environmental Disease

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Minamata Disease,Mercury Pollution in World

  • 원전정순
    • 한국환경보건학회:학술대회논문집
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    • 한국환경보건학회 2004년도 International Conference Global Environmental Problems and their Health Consequences
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    • pp.31-44
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    • 2004
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Outbreak of Phytophthora Rot on Pear Under Environmental Conditions Favorable to the Disease

  • Jee, Hyeong-Jin;Cho, Weon-Dae;Nam, Ki-Woong;Park, Young-Seob
    • The Plant Pathology Journal
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    • 제17권4호
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    • pp.231-235
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    • 2001
  • From April to May 1998, Phytophthora rot on pear, which has not been reported in Korea before, became an epidemic in the southeast part of the country under abnormally higher temperature and prolonged rainy days. Average temperature was about $3^{\circ}$ higher than in normal years, and 29 days were rainy during the 2 months in the areas surveyed. Over 1,000 orchards estimated at about 270 ha in 19 cultivation areas were infected by the disease, which occurred on all parts of the tree such as leaves, shoots, branches, stems, and flower clusters. Among 43 isolates collected from various locations and plant parts, 41 were identified as Phytophthora cactorum while 2 were identified as P. cambivora based on their mycological characteristics. The representative isolates revealed strong pathogenicity not only to pear but also to apple and peach. Among 23 pear cultivars tested, 7 were estimated as susceptible, 4 were moderate, and 11 were resistant to the pathogen. Results suggest that Phytophthora disease on pear is a potential threat to pear cultivation when environmental factors are favorable to disease development.

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Antifungal and Plant Growth Promotion Activities of Recombinant Defensin Proteins from the Seed of Korean Radish (Raphanus sativus L.)

  • Hwang, Cher-Won
    • 한국환경농학회지
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    • 제28권4호
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    • pp.435-441
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    • 2009
  • In the present study, we analyzed the defensin protein deduced from Korean radish (Raphanus sativus L.) seeds.To express the genes in E. coli, we constructed a recombinant expression vector with a defensin gene, named rKRs-AFP gene isolated from Korean radish seeds. Over expressed rKRs-AFP proteins was separated by SDS-PAGE to determine the purity, and protein concentration was determined by the Bradford method. Antifungal activity was assessed by disk assay method against the tested fungi. As a result, when 500 mL of cell culture were disrupted by sonicator, 32.5 mg total proteins were obtained. The purified protein showed a single band on SDS-PAGE with estimated molecular weight about 6 KDa, consistent with the molecular mass calculated from the deduced amino acid sequence. The purified rKRs-AFP protein showed remarkable antifungal activities against several fungi including Aspergillus niger, Botrytis cinerea causing the gray mold disease, and Candida albicans. In field tests using the purified rKRs-AFP protein, the protein showed the reducing activity of disease spot and the mitigating effect of spreading of disease like agrichemicals. The immuno-assay of rKRs-AFP protein showed that the purified protein entirely accumulated at B. cinerea cytoplasm through the hyphal septa shown by fluorescence imaging. There was no fluorescence inside the cell, when the hypha was incubated without the protein. These all results indicate that the recombinant rKRs-AFP proteins can be utilized as a potential antifungal drug to control harmful plant fungal pathogens.

Antagonistic Effect of Streptomyces sp. BS062 against Botrytis Diseases

  • Kim, Young-Sook;Lee, In-Kyoung;Yun, Bong-Sik
    • Mycobiology
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    • 제43권3호
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    • pp.339-342
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    • 2015
  • The use of microorganisms and their secreted molecules to prevent plant diseases is considered an attractive alternative and way to supplement synthetic fungicides for the management of plant diseases. Strain BS062 was selected based on its ability to inhibit the mycelial growth of Botrytis cinerea, a major causal fungus of postharvest root rot of ginseng and strawberry gray mold disease. Strain BS062 was found to be closely related to Streptomyces hygroscopicus (99% similarity) on the basis of 16S ribosomal DNA sequence analysis. Postharvest root rot of ginseng and strawberry gray mold disease caused by B. cinerea were controlled up to 73.9% and 58%, respectively, upon treatment with culture broth of Streptomyces sp. BS062. These results suggest that strain BS062 may be a potential agent for controlling ginseng postharvest root rot and strawberry gray mold disease.

Soil-Environmental Factors Involved in the Development of Root Rot/Vine on Cucurbits Caused by Monosporascus cannonballus

  • Kwon, Mi-Kyung;Hong, Jeong-Rae;Kim, Yong-Hwan;Kim, Ki-Chung
    • The Plant Pathology Journal
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    • 제17권1호
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    • pp.45-51
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    • 2001
  • A root rot/vine decline disease occurred naturally on bottle gourd-stocked watermelon, melon, oriental melon and squash grown in greenhouses, but not on these plants grown in fields. Self-rooted watermelon, cucumber, pumpkin and luffa were also proven to be hosts of the pathogen by artificial inoculation in this experiment. The pathogen was identified as Monosporascus cannonballus by comparing microscopic characteristics of fungal structures with those of previously identified fungal strains. Our field investigations showed that the temperature and electric conductivity of soil in infected greenhouses were higher and the soil moisture content was lower than in noninfected greenhouses. To investigate soil-environmental factors affecting disease development, greenhouse trials and inoculation experiments were conducted. The host plants inoculated and grown under conditions of high soil temperature and electrical conductivity ($35\pm2^{\circ}$, 3.2-3.5 mS) and with low soil moisture content (pF 3.0-4.5) were most severely damaged by the fungal disease. Since plants growing in greenhouses ae usually exposed to such environmental conditions, this may be the reason why the monosporascus root rot/vine decline disease has occurred only on cucurbits cultivated in greenhouses but not in field conditions.

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