• Mycobiology
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• 제39권2호
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• pp.113-117
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• 2011

A laboratory experiment was conducted to study the induction of constricting rings and test predation of Dactylaria brochopaga isolates against second stage juveniles (J2s) of Meloidogyne graminicola. Among the five fungal isolates, isolate D showed the greatest number of predatory rings and, consequently, trapped the maximum number of M. graminicola J2s in dual cultures. Another pot experiment was conducted to study the effect of D. brochopaga (isolate D) on the management of wheat root-knot disease. Applying a mass culture (10 g/pot) and a spore suspension of the fungus with and without cow dung manure to soil infested with 2,000 M. graminicola juveniles significantly improved plant height, root length, weights of shoots, roots, panicles and grains per hill compared to those in the control. Moreover, the fungus significantly reduced the number of root-knots, the number of egg masses, juveniles, and females per hill compared to those in the control. Bio-efficacy of the fungus was heightened when the mass culture and a spore suspensions were used in combination with cow dung manure to improve the plant growth parameters and reduce the number of root-knot and reproductive factors. Further investigations should be conducted to identify the impact of this fungus in the field.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.104.1-104
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• 2003

To screen for potential biocontrol agents against postharvest disease of garlics caused by Penicillium hirsutum, a total of 933 isolates (432 fungi and 501 bacteria) were isolated from the rhizoshere or rhizoplane of garlics. Among them, Pantoea agglomerans isolate 59-4 (Pa 59-4) was selected for a potential biocontrol agent by in vivo wounded garlic bulb assay, When the spore suspension (10$\^$5/ spores/$m\ell$) of Penicillium hirsutum was co-inoculated with spore or cell suspension of each fungal or bacterial isolate on wounded garlics, the isolate highly suppressed disease development. Soaking garlic bulbs in the suspension of Pa 59-4 significantly reduced garlic decay from p. hirsutum. However, Pa 59-4 did not inhibit the mycelial growth of P. hirsutum in dual-culture with P. hirsutum on Tryptic soy agar. In order to elucidate mode of action of Pa 59-4 nutrient competition between Pa 59-4 and P. hirsutum was investigated using tissue culture plates with cylinder inserts containing defusing membrane reported by Janisiewicz et al. The results showed that Pa 59-4 effectively suppressed spore germination and mycelial growth of blue mold in the low concentration (0.5％) of garlic juice, but did not suppress those of blue mold in the higher concentration (5％) of garlic juice. This result suggests that the mechanism in biocontrol of garlic blue mold by Pa 59-4 may involve in nutrient competition with P. hirsutum on garlic bulbs.

• 한국응용곤충학회지
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• 제12권1호
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• pp.23-27
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• 1973

갈색엽고병(Fusarium niwate)의 효과적인 접종방법을 찾아내기 위해 본 시험을 수행하였던 바 다음과 같은 결과를 얻었다. 1) 본 균의 분생포자의 증류수 현탁액을 벼 유묘에 분무접종할 때, 접종 후 습실에 1일 보존했을 경우에는 거의 발병이 되지 않았으나 2일간 보존한 겅우에는 어느 정도 병반이 나타났다. 2) 벼 유묘에 바람이나 또는 나무막대기로 물리적인 상처를 입힌 다음 증류수 포자현탁액을 분무한 결과 상당한 병만이 형성되었다. 3) 포자현탁액에 벼 잎 추출액, glucose, polypeptone, yeast exract 등의 $1\%$ 용액을 첨가 분무접종했을 때 병반형성이 양호하였다. 4) 포자발아상태는 종류수중에서는 불량하였으나 영양분을 첨가한 용액중에서는 발아력도 좋았고 균사의 융합도 양호하게 일어났다. 5) 본 접종시험의 결과 통일품종은 재래 장려품종인 풍광에 비해 본 병에 대해 약했다.

• 식물병연구
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• 제15권3호
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• pp.217-221
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• 2009

Fludioxonil은 미국 EPA에 의해 저독성(reduced-risk) 살균제로 분류되었으며, 이 살균제는 Pseudomonas pyrrocinia가 생산하는 항균 물질인 pyrrolnitrin을 선도 물질로 하여 합성하였다. 본 연구에서는 상추 품종, 기주 식물의 생육 시기, Botrytis cinerea 포자농도, 접종원의 영양분 농도 등의 발병 조건에 따른 fludioxonil의 상추 잿빛곰팡이병에 대한 방제효과를 온실에서 실험하였다. 상추의 생육시기에 따른 fludioxonil 방제효과를 실험한 결과, 2 ${\mu}g$/ml 처리구는 어린 유묘에서 잿빛곰팡이병 방제효과가 더 높았으나, 10 ${\mu}g$/ml 이상 농도에서는 생육 시기에 따른 방제효과의 차이는 거의 없었다. 또한 fludioxonil 10 ${\mu}g$/ml 이상 농도 처리구는 B. cinerea의 포자 농도(2.5$\times$10개/ml 부터 $2{\times}10^6$ 개/ml까지)에 관계없이 모두 우수한 방제효과를 나타냈다. 반면에 fludioxonil 2 ${\mu}g$/ml은 접종원의 포자농도가 높을수록 낮은 방제효과를 보였다. 그리고 영양분농도에 따른 fludioxonil의 잿빛곰팡이병 방제효과를 실험한 결과, potato dextrose broth의 농도가 낮을수록 fludioxonil은 상추 잿빛곰팡이병에 대한 높은 방제효과를 나타냈다. 이상의 결과로부터 살균제 fludioxonil은 상추 잿빛곰팡이병에 대한 효과적인 살균제임을 알 수 있었으며, 다만 낮은 농도에서는 발병 조건에 따라 다소 낮은 방제효과를 나타낼 수 있을 것이다.

• 한국환경농학회지
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• 제30권4호
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• pp.453-458
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• 2011

BACKGROUND: Coleosporium plectranthi, an obligate parasite, which is responsible for the rust disease of Perilla frutescens, a plant in Korea, commonly known as Perilla. All rusts are obligate parasites, meaning that they require a living host to complete their life cycle. They generally do not kill the host plant but can severely reduce growth and yield. Food and feed spoilage fungi cause great economic losses worldwide. It is estimated that between 5 and 10% of the world food production is wasted due to fungal deterioration. Rust disease of Perilla is highly frequent and is widely spread in Korea. The present study was designed to investigate a novel media for the urediniospore germination in vitro and anti-rust activity as well as GC-MS analysis of oak pyroligneous liquor. METHOD AND RESULTS: Urediniospores were collected from the infected leaf of Perilla. Spore suspension was made and the suspension was inoculated in the 2% water agar media with proper humidity, then they were incubated at $26^{\circ}C$ for 56 hrs. The GC-MS analysis of the oak pyroligneous liquor was also done to check the chemical composition. GC-MS analysis of the wood vinegar was found 15 compounds, among them o-mthoxyphenol (25.93%), 2,6-dimethoxyphenol (16.06%), 4-methylenecyclohexanone (10.69%), 2,3-dihydroxytoluene (7.84%), levoglucosane (6.14%) and propanoic acid (5.32%) were the major components. Different concentration of the oak pyroligneous liquor was used, and spore inhibition was recorded on the basis of spore counting. The best results were noted at the concentration of 50% solution where 31.8% spores were inhibited. CONCLUSION: On the basis of the chemical composition of the oak pyroligneous liquor and the activity recorded we can use it as an anti-rust agent.

• 한국군사과학기술학회지
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• 제11권2호
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• pp.101-108
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• 2008

This study attempted to develop the technology by gaseous ozone for decontaminating building affected by a model of biological weapon agent(Bacillus subtilis spores) instead of Bacillus anthracis spore. The use of ozone is attractive method from a practical point of view of decontamination procedure since it has strong oxidation power but no residue after application. We examined the disinfection efficiency of gaseous ozone to Bacillus subtilis spores which suspension was sprayed on different material surfaces and dried. Three different types of gaseous ozone was applied : dry ozone, dry ozone with humidified air, and water bubbled wet ozone. Dry ozone(1500ppm) failed to achieve any significant inactivation for 2hrs. However, six log reduction of B. subtilis spore was achieved within 30min by 1500ppm of water bubbled wet ozone. This result shows the noticeable inactivation efficiency by gaseous ozone compared with previous studies. Good performance by wet ozone was also found for military material surface.(i.e. : gas mask hood, protective garments, army peinted metal surface).

• 한국미생물·생명공학회지
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• 제23권2호
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• pp.236-242
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• 1995

Biological control of soilborne plant pathogens by the addition of antagonistic microorganisms to the soil may offer a practical supplement or alternative to existing disease management strategies that depend heavily on chemical pesticides. Soil amendment with antagonistic microbes was non-effective because of high cost, low efficacy, and inconvenient usage on the treatment course. Therefore, seed coating formulation for the application of biological seed treatments has been being to apply successful disease suppression for many important crops. The objectives of this study were to investigate the optimal condition for the spore production of biocontrol agent Bacillus subtilis YBL-7 and the liquid coating formulation that contained a suspension of a proper aqueous binder, as well as a ground fine solid particulate material. The maximum yield has been obtained from 60 hrs-old culture at 30$\circ$C in spore forming (SF) medium containing 0.8% nutrient broth, 0.05% yeast extract, 10$^{-1}$ M MgCl$^{2}$, 10$^{-4}$ M MnCl$^{2}$, 10$^{-5}$ M dipicolinic acid, and pH 6.5. The optimal condition of dried spore preparation was achieved when cells of B. subtilis YBL-7 was heat-dried with 50$\circ$C for 2 hrs.

• Preventive Nutrition and Food Science
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• 제12권4호
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• pp.251-258
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• 2007

Thermal resistance and heat activation characteristics of Clostridium botulinum ATCC 25763 spores were evaluated. The effects of nisin and pH on the activation and subsequent germination were also investigated. Spores of C. botulinum were not inactivated by heat treatments up to $92^{\circ}C$ for 2 hr. Heat treatment at $85^{\circ}C$ for 90 min was selected as the optimal activation condition based on monitoring subsequent germination. L-alanine alone or in combination with L-cysteine was not sufficient to germinate the spores of this strain. Tryptone-Peptone- Glucose-Yeast extract (TPGY) broth supplemented with L-alanine was used as a suitable germination medium. Decreasing pH of activation suspension increased the degree of phase darkening, i.e., germination. In addition, the presence of nisin during activation increased the degree of phase darkening. The majority of spore populations were dormant at a pH of less than 2.8, and these populations required heat activation to increase the culturability on TPGY agar medium. However, extended heating in the presence of nisin at pH 2.8 decreased the spore count; however, heat activation was less necessary at pH 3.4, compared at pH 2.8.

• 식물병연구
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• 제11권1호
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• pp.43-47
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• 2005

Flisulfamide 입제의 포장에서 방제효과 변화를 조사하기 위하여 강릉신의 배추 뿌리혹병에 오염된 고랭지 포장에서 본 시험을 진행하였다. Flisulfamide 입제는 84.6% 의 방제가로 무처리구와 기타 대조약제에 비교하여 통계적으로 유의성이 있는 것으로 나타났다. 휴면포자의 감소율을 조사하기 위하여 시험포장의 모든 처리구의 각 반복당 임의의 5개 지점에서 약제 처리 전 토양과 약제 처리 후 토양을 채집하여, 토양내의 휴면포자의 밀도를 조사하였다. 처리 전 시험 포자으이 휴면포자 밀도는 균일하지 않았으므로 포장 시험시 처리전 휴면포자 밀도의 조사가 필요하다고 생각된다. 휴면포자의 감소율을 조사한 결과, flisulfamide 분제와 입제를 처리한 후 휴면포자 밀도는 처리전에 비하여 63.7% 와 64.2% 의 감소율을 나타냈다. 방제효과와 휴면포자의 감소율간에는 유효적인 상관관계가 있게 나타났다. 그리고 약제 처리에 의한 수확량 변화를 조사하기 위하여, 약제 처리 45일 후, 각 처리구에서 20주의 배추를 수확하여 지상부 무게를 측정하였다. Flisulfamide 분제, fluazinam 분재와 flisulfamide 입제의 처리구에서 수확량은 무처리구에 비하여 14.3%, 13.8%와 13.0% 의 수확량 증가율을 나타냈고, trifloxystrobin 액상수화제의 처리구에서 수확량은 무처리구에 비하여 3.8%의 증가율을 나타냈다. 대조구를 포함한 각 처리평균간에는 통계적 유의성(P=0.05)은 없는 것으로 나타났다. 이상의 결과로부터 flisulfamide 입제가 배추 뿌리혹병의 방제에 있어서 우수한 방제효과를 가지고 있으며, 또한 휴면포자의 밀도를 감소하는데 효과적임을 알 수 있다.

• 한국식물병리학회지
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• 제14권4호
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• pp.325-330
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• 1998

On the basis of the fact that the pycnidiospore of Botryosphaeria dothidea, the causal fungus of apple white rot is a typical water borne spore, a method for quantitative analysis of pycnidiospore dispersal from the warts produced on the diseased apple tree stem was developed. The warts on which cracks developed either on or around them were cut off at the base, and shaked in the water for 4hours at 2$0^{\circ}C$, in which condition the maximum number of spores were released. The volume of shaking solution was calculated as 1 ml per one wart. At the end of shaking, Trio, a household detergent was added to the shaking solution to the concentration of 0.1%, and shaked for additional 10 minutes at 35$^{\circ}C$ to take off the spores attached on the glass ware. One milliliter of the spore suspension thus prepared were passed through transparent membrane filter (pore size : 3.0 ${\mu}{\textrm}{m}$), and the spores attached on the filter were counted under a microscope ($\times$200) after staining them with lactophenol supplemented with aniline blue. The results thus obtained were statistically consistent when at least 30 warts were used simultaneously in single shaking. This method can be applicable in the elucidation of ecology of sporulation and spore dispersal, and also in the screening of the sporulation inhibitor which can be used in the control of the disease by reducing the inoculum density.