• Korean Journal Plant Pathology
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• v.10 no.4
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• pp.325-332
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• 1994

In order to find out formulation and effect of soil amendment on Fusarium wilt of sesame caused by Fusarium oxysporum f. sp. vasinfectum, the study was conducted during the last two years of 1992 to 1993. Among 14 chemicals (1%, w/w) added to soil including CaO individually, Al2(SO4)3, Alum, and CaO suppressed mycelial growth and conidial germination of F.oxysporum f. sp. vasinfectum. CaCl2 suppressed mycelial growth only, while glycerine, KCl, K2 HPO4, and triple superphosphate suppressed conidial germination. Suppression rate was ranged from 21 to 100% on mycelial growth. The 8 chemicals were finally selected. Among the 4 organic compounds, composted pine bark showed definite suppression on mycelial growth and conidial germination of the fungus, whereas milled alfalfa leaves was only effective on conidial germination of Fusarium wilt pathogen. The antagonist Trichoderma harzianum grew well in the soil medium amended with the composted pine bark and chemicals mixture (CPM) amendment (1%, w/w) and suppressed mycelial growth of the fungus effectively. In pot test, Fusarium wilt of sesame was completely controlled by CPM amendment.

• FLOWER RESEARCH JOURNAL
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• v.19 no.4
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• pp.245-247
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• 2011

A new spray carnation cultivar 'Leo' was released by the National Institute of Horticultural and Herbal Science in 2003. A cross was made between spray cultivar 'Ballantyne' and 'West peachy' in 1999. After investigation of the characteristics four years (from 2001 to 2003), it was finally selected in 2003. 'Leo' is a spray cultivar with light yellow color for a cut flower. The main characteristics are multi branching, long vase life and early flowering habit than 'Diamond'(control). It has medium resistance to Fusarium wilt and 9 days vase life.

• The Korean Journal of Mycology
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• v.25 no.1 s.80
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• pp.10-19
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• 1997

Fusarium wilt of radish (Raphanus sativus L.) is caused by the Fusarium oxysporum f. sp. raphani (FOR) which mainly attacks Raphanus spp. The pathogen is a soil-borne and forms chlamydospores in infected plant residues in soil. Infected pathogen colonizes the vascular tissue, leading to necrosis of the vascular tissue. Growth promoting beneficial organisms such as Pseudomonas fluorescens WCS374 (strain WCS374), P. putida RE10 (strain RE10) and Pseudomonas sp. EN415 (strain EN415) were used for microorganisms-mediated induction of systemic resistance in radish against Fusarium wilt. In this bioassy, the pathogens and bacteria were treated into soil separately or concurrently, and mixed the bacteria with the different level of combination. Significant suppression of the disease by bacterial treatments was generally observed in pot bioassy. The disease incidence of the control recorded 46.5% in the internal observation and 21.1% in the external observation, respectively. The disease incidence of P. putida RE10 recorded 12.2% in the internal observation and 7.8% in the external observation, respectively. However, the disease incidence of P. fluorescens WCS374 which was proved to be highly suppressive to Fusarium wilt indicated 45.6% in the internal observation and 27.8% in the external observation, respectively. The disease incidence of P. putida RE10 mixed with P. fluorescens WCS374 or Pseudomonas sp. EN415 was in the range of 10.0-22.1%. On the other hand, the disease incidence of P. putida RE10 mixed with Pseudomonas sp. EN415 was in the range of 7.8-20.2%. The colonization by FOR was observed in the range of $2.4-5.1{\times}10^3/g$ on the root surface and $0.7-1.3{\times}10^3/g$ in the soil, but the numbers were not statistically different. As compared with $3.8{\times}10^3/g$ root of the control, the colonization of infested ROR indicated $2.9{\times}10^3/g$ root in separate treatments of P. putida RE10, and less than $3.8{\times}10^3/g$ root of the control. Also, the colonization of FOR recorded $5.1{\times}10^3/g$ root in mixed treatments of 3 bacterial strains such as P. putida RE10, P. fluorescens WCS374 and Pseudomonas sp. EN415. The colonization of FOR in soil was less than that of FOR in root part. Based on soil or root part, the colonization of ROR didn't indicate a significant difference. The colonization of introduced 3 fluorescent pseudomonads was observed in the range of $2.3-4.0{\times}10^7/g$ in the root surface and $0.9-1.8{\times}10^7/g$ in soil, but the bacterial densities were significantly different. When growth promoting organisms were introduced into the soil, the population of Pseudomonas sp. in the root part treated with P. putida RE10 was similar in number to the control and recorded the low numerical value as compared with any other treatments. The population density of Pseudomonas sp. in the treatment of P. putida RE10 indicated significant differences in the root part, but didn't show significant differences in soil. The population densities of infested FOR and introduced bacteria on the root were high in contrast to those of soil. P. putida RE10 and Pseudomonas sp. EN415 used in this experiment appeared to induce the resistance of the host against Fusarium wilt.

• Research in Plant Disease
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• v.15 no.1
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• pp.30-35
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• 2009

This study was carried out to determine the causal agents of soil-borne fungal diseases that pose a threat to the muskmelon production in Cheong Yang, Korea and to investigate the potential effects of hot water drenching and three fumigant (metam sodium, dazomet and methyl bromide) on these diseases. As the agents of the diseases, Monosporascus cannonballus, Didymella sp., Fusarium sp., Phytophthora sp., were detected. Hot water and the fumigants were treated on two successive cropping seasons of melon. Soil temperature was measured at 0, 10, 20 and 30 cm soil depth. In 2005, soil sterilization by hot-water was more effective significantly to control of the diseases than by fumigant. yield was the highest in hot-water sterilized plot as $39\;ton{\cdot}ha^{-1}$. Dazomet ($50\;g/m^2$) treated plot was followed as $23\;ton{\cdot}ha^{-1}$. In 2006, hot water sterilized plot showed higher yields than non-treated plots ($14.8\;ton{\cdot}ha^{-1}$). But the other three fumigant contained Dazomet ($50\;g/m^2$) were no difference (P<0.05) in yield.

• Korean Journal of Environment and Ecology
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• v.23 no.4
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• pp.333-345
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• 2009

Carpinus laxiflora communities are known as the climax forest community of the temperate zone of Korea. There are three Carpinus laxiflora communities in Seoul. The purpose of this research is to analyze the characteristics of Carpinus laxiflora communities of Seoul and supply basic data for establishing of a management plan. The research sites are Sahmyook University, Mountain Dobong and Jinkwandong. This study considers investigation and the analysis of communities structure, soil characteristics and the growth increment of trees. As the result of study, we could know that the growth increment of the Carpinus laxiflora trees of Seoul is decreasing recently because of soil acidification and so on. Also the vegetation disturbance is increasing because of naturalized plant. Oak wilt disease has appeared in the oak forest around Sahmyook University that is the largest Carpinus laxiflora communities area in Seoul. For that reason the open gap was appeared in forest, and the spread of naturalized plants has been increasing in the gap. Furthermore, the Carpinus laxiflora trees are affected by the Platypus koryoensis which is a kind of oak wilt disease. And so, Unless there is a specific management plan, the survival of Carpinus laxiflora communities are uncertain in Seoul. Therefore the management plan of Carpinus laxiflora communities is necessary such as precise investigation, annual monitoring, etc. For the conservation of the Carpinus laxiflora communities, it is necessary to establish the management plan of the biodiversity for Seoul area.

• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.1-11
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• 2001

Climate in the year of 2000 was characterized as a long severe drought in tile spring, unusually high and low temperature in summer, two times of typoons, and floods by heavy rains in fall. Rice leaf and panicle blast and bacterial grain rot occurred severely comparing with 1999 and Bipolaris leaf spot spread over tile country. Phytophthora blight and anthracnose in red-pepper became epidemic especially in the late season causing severe yield losses. Tomato fusaruim wilt, CGMMV, powdery mildew, and sudden wilt syndrom of cucurbits and strawberry powdery mildew were also severe in 2000. In garlic, sclerotium rot occurred severely mainly due to the frequent rainfalls in planting time and much snowfalls in 1999's winter. Spring potato had severe infection of viruses due to a long spring drought, and fall potato had high incidence of bacterial soft rot and bacterial wilt due to fall floods by heavy rains. In sweet potato fusarium wilt was the most severe as in other year. Disease incidence of apple and pear trees was rotatively mild compared with previous years. In wheat and barley, Gibberella petch rarely occurred because of spring drought.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.94-100
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• 2006

To isolate a bacterium that produces plant growth promoting hormone, a total of 29 bacteria were obtained from the soil in Gyeongsan, Korea. Among these, 14 strains were selected by their positive reaction on Salkowski to produce auxin. All of these were then tested for their property to produce siderophore using CAS (chrome azurol S) blue agar, and one was chosen for its ability to produce both, auxin and siderophore. This strain, denoted, AHl8, showed 1.5 times higher adventitious root induction rates than controls, using mung-beans. The strain also showed efficient biocontrol properties towards Fusarium-wilt of tomatoes in artificial pot assays. The strain was identified as Bacillus subtilis by 16s rDNA comparison and Biolog analyses. Growth and media conditions for Bacillus subtilis AH1 8 to highly produce siderophore were also investigated.

• Microbiology and Biotechnology Letters
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• v.32 no.4
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• pp.312-316
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• 2004

In oder to select the powerful rhizophere-dorminatable biocontrol agent, we had isolated an indigenous antagonistic bacterium which produced antibiotic and siderophore from a disease suppressive local field soil of Gyungsan, Korea. And we could select the Pseudomosp. 4059 which can strongly antagonize against Fusarium oxysporum and Phytophthora capsici by two kinds of antifungal mechanism that can be caused by the antibiotic of Phenazin, a siderophore and a auxin like subThe selected strain was identified as Pseudomonas fluorescens (biotype A) 4059 by biochemical tests, API $\textregistered$ test, MicroLog TM system and 16S rDNA analysis. The selected antagonistic microorganism, Pseudomosp. 4059 had an antifungal mechanism of antifungal antibiotic and sidrophore. And we were confirmed the antagonistic activity of P fluorescens 4059 with in vitro antifungal test against Phytophthora capsici and in vivo by red-pepper.

• The Korean Journal of Mycology
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• v.24 no.1 s.76
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• pp.49-55
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• 1996

This study was conducted to find out antifungal activities of entomopathogenic fungus, Metarhizium anisopliae, against phytopathogenic fungi, Fusarium oxysporum, Botrytis cinerea and Alternaria solani. M. anisopliae was confirmed its antagonistic effect through mycelial inhibition zone of phytopathogenic fungi by culture filtrate of the antagonist. The filtrate (30%: v/v) inhibited the conidial germination of B. cinerea and F. oxysporum to 21.5% (control: 88.2%) and 53.0% (control: 78.6%), respectively and delayed the start of spore germination about 8hours. Microscopic observations proved that the addition of 10% culture filtrate of M. anisopliae restricted the growth of phytopathogenic fungus, F. oxysporum, to the formation of chlamydospore. From these results, we concluded that an addition effect of the filtrate from M. anisopliae on culturing F. oxysporum was fungistatic.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.351-353
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• 2017

Chryseobacterium sp. strain T16E-39, isolated from roots of a tomato plant, promotes plant growth and suppresses phytophthora blight and bacterial wilt diseases. The complete genome of strain T16E-39 consists of a circular chromosome with 4,872,888 base pairs with a G + C content of 35.22%. The genome includes 4,289 coding sequences, 15 rRNAs, and 71 tRNAs. We detected genes involved in phosphate solubilization, phytohormone regulation, antioxidant activity, chitin degradation, and the type IX secretion system (T9SS) that may be related to growth promotion and disease suppression in plants.