• 식물병연구
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• 제16권1호
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• pp.41-47
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• 2010

고추 역병이 발생한 충주, 안면, 태안, 안동, 음성 그리고 괴산지역의 고추밭 토양에서 전체 10,753균주의 저영양 미생불을 분리하였다. 이들 중 Phytophthora capsid를 포함하여 식불체의 주요 병원성 곰팡이에 대해 길항작용을 보이는 균주들을 일차적으로 선발하였다. 최종적으로는 온실 고추유묘 검정을 통해 고추 역병에 대해 탁월한 방제가를 보이는 7F 균추가 선발되었다. 이 균주는 16SrDNA염기서열 분석과 API20 NE 키트를 통한 생리, 생화학적 분석을 통하여 Bacillus subtilis로 동정 되었다. 고추 역병균 포자를 처리한 고추 유묘 화분 검정에서, 처리25일 후 대조구는 고추 역병 이병 비율이 87%에 이르는 반면에 7F 균주를 처리한 처리구에서는 단지 6%의 이병율을 보였다.

• The Plant Pathology Journal
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• 제18권3호
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• pp.138-141
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• 2002

A promising biocontrol agent, A2l-4, against Phytophthora blight of pepper was selected from 351 bacterial isolates collected from rhizosphere soils and roots of onion (Allium fistulosum L.). The isolate A21-4 was identified as Serratia plymuthica based on its 16S rRNA sequence and key characteristics as compared with that of an authentic culture of S. plymuthica (ATCC No. 6109D01). The isolate readily colonized on roots of various crops including pepper when inoculated on seed and not. Strain A2l-4 showed narrow spectrum of antibiotic activity, as revealed in its strong inhibitory activity to the genera Pythium and Phytophthora, but not to Fuasrium and Rhizoctonia. In pot experiments, none of the pepper seedlings treated with A2l-4 were infected by Phytophthora capsici, while 86% of the control plants were killed by the pathogen.

• 원예과학기술지
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• 제28권5호
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• pp.802-809
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• 2010

역병은 세계적으로 고추에 발생하는 병 중 가장 문제시 되는 병해로 국내 83개 지역에서 채집한 재래종 고추 유전자원 중 300개를 선발하여 공시하였다. 파종 후 온실에서 70일간 육묘하였고 공시한 역병균의 유주자낭 농도를 $10^5/mL$으로 하여 주당 5mL 관주접종 후, 습실 처리하였고 1주 간격으로 4주간 이병주율을 조사하였다. 접종 7일 후 이병주율을 조사하였더니, 공시한 300개 고추 자원 중 67개 자원에서 이병주율이 60.1% 이상으로 높은 감수성을 보였으며, 37개 자원은 접종 후 7일까지 전혀 발병하지 않았다. 역병균 접종 28일 후, 공시한 300점의 고추자원 중 244개 자원은 60% 이상의 이병주율을 보여 역병에 대해 감수성을 나타내었으며, 11개 자원은 20% 미만의 이병주율을 보여 중도저항성을 보였고, 5개 자원은 전혀 발병하지 않아 저항성을 나타내었다. 5개 자원의 저항성 고추유전자원은 역병저항성 고추 품종 육종에 유용한 중간모본으로 사용될 것으로 생각된다. 본 실험의 정밀도를 높이기 위해 분자마커를 활용한 추가실험이 진행된다면 고추유전자원의 역병 저항성에 대한 중요한 정보를 제공할 수 있을 것으로 본다.

• The Plant Pathology Journal
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• 제29권2호
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• pp.154-167
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• 2013

We previously developed a sequential screening procedure to select antagonistic bacterial strains against Phytophthora capsici in pepper plants. In this study, we used a modified screening procedure to select effective biocontrol strains against P. capsici; we evaluated the effect of selected strains on Phytophthora blight and anthracnose occurrence and fruit yield in pepper plants under field and plastic house conditions from 2007 to 2009. We selected four potential biocontrol strains (Pseudomonas otitidis YJR27, P. putida YJR92, Tsukamurella tyrosinosolvens YJR102, and Novosphingobium capsulatum YJR107) among 239 bacterial strains. In the 3-year field tests, all the selected strains significantly (P < 0.05) reduced Phytophthora blight without influencing rhizosphere microbial populations; they showed similar or better levels of disease suppressions than in metalaxyl treatment in the 2007 and 2009 tests, but not in the 2008 test. In the 2-year plastic house tests, all the selected strains significantly (P < 0.05) reduced anthracnose incidence in at least one of the test years, but their biocontrol activities were variable. In addition, strains YJR27, YJR92, and YJR102, in certain harvests, increased pepper fruit numbers in field tests and red fruit weights in plastic house tests. Taken together, these results indicate that the screening procedure is rapid and reliable for the selection of potential biocontrol strains against P. capsici in pepper plants. In addition, these selected strains exhibited biocontrol activities against anthracnose, and some of the strains showed plant growth-promotion activities on pepper fruit.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.67.1-67
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• 2003

Phytophthora blight is a devastating disease of pepper and occurs almost anywhere peppers are grown. Phytophthora blight is caused by Phytophthora capsici and this pathogen can infect every part of the plant by moving inoculum in the soil, by infecting water on surface, by aerial dispersal to sporulating lesions. Management of Phytophthora blight currently relies on cultural practices, crop rotation, and use of selective fungicides. Since these treatments are a short-term management, a classical breeding for development of resistant pepper against the Phytophthora is an alternative. So far some of the resistant cultivars have been on the market, but those are limited regionally and commercially. Therefore, ultimately an elite line resistant against this disease should be developed, if possible, by biotechnology. We have set out a series of work recently in order to develop Phytophthora resistant pepper cultivar. For the first time, the cDNA microarray analysis was peformed using an EST chip that holds around 5000 pepper EST clones to identify genes responsive to Phytophthora infection. Total RNA samples were obtained from Capsicum annuum PI201234 after inoculating P. capsici to roots and soil and exposed to the chip. .Around 900 EST clones were up-regulated and down-regulated depending on the two RNA sample tissues, leaf and root. From those, we have found 55 transcription factors that may be involved in gene regulation of the disease defense mechanism. Further and in detail information will be provided in the poster.

• The Plant Pathology Journal
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• 제23권2호
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• pp.109-112
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• 2007

This study was to examine the efficacy of a root-dipping application of antagonistic bacterial strains for the control of Phytophthora blight of pepper caused by P. capcisi, and to evaluate their plant growth-promoting effects in the field in 2005 and 2006. The candidate antagonistic rhizobacterial strains CCR04, CCR80, GSE09, ISE13, and ISE14 were treated by dipping plant roots with bacterial suspensions prior to transplanting. The candidate rhizobacterial strains CCR04, CCR80, GSE09, and ISE14 significantly (P=0.05) reduced the disease incidence and the area under the disease progress curves when compared to buffer-treated controls in at least a year test. The metalaxy l(fungicide-treated control) resulted in one of the lowest disease incidences among the treatments in both years. Moreover, the strains CCR04, CCR80, GSE09, and ISE13 significantly (P=0.05) increased the fruit weights and/or numbers of peppers in at least a year test compared to the buffer-treated controls. These results suggest that the antagonistic rhizobacterial strains CCR04, CCR80, and GSE09 could be efficient biocontrol agents by controlling Phytophthora blight of pepper and promoting the plant growth when treated with root-dipping at transplanting.

• 식물병연구
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• 제17권1호
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• pp.1-12
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• 2011

충북의 고추 주산지인 청원, 보은, 음성, 괴산의 포장에서 고추 역병 발생에 따른 이병주율과 수량과의 관계를 조사하였다. 괴산을 제외한 3개의 시험포장에서 고추 역병의 증가는 수량감소를 가져왔다. 고추 역병 이병주율과 수량 사이의 높은 상관을 나타내는 수확시기는 청원에서는 3차, 보은에서는 2차 수확기로 나타나 지역별로 다소 차이를 보였다. 이와는 달리 저항성 대목을 이용하여 접목재배를 한 괴산 시험포장에서는 고추 역병 발생량과 수량 사이에 매우 낮은 상관을 나타냈다. 청원 시험 포장에서 이병주율 100%에 도달하는 데 소요되는 시기는 2006년에 비해 2007년에 40일 이상 늦어졌다. 고추 역병 발생이 적었던 포장(이병주율 5% 이하)에서 수량감소 5%를 가져오는 고추 역병 요방제 수준은 0.8%로 설정되었다.

• The Plant Pathology Journal
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• 제23권3호
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• pp.180-186
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• 2007

The biocontrol agent, Serratia plymuthica A21-4, has been developed for controlling pepper Phytophthora blight. Serratia plymuthica A21-4 strongly inhibits the mycelial growth, zoospore formation, and cyst germination of Phytophthora capsici in vitro. The application of a cell suspension of strain A21-4 to pepper plants in pot experiments and in greenhouse successfully controlled the disease. The bacteria produced a potent antifungal substance which was a key factor in the suppression of Phytophthora capsici. The most active chemical com-pound was isolated and purified by antifungal activity-guided fractionation. The chemical structure was identified as a chlorinated macrolide $(C_{23}H_{31}O_8Cl)$ by spectroscopic (UV, IR, MS, and NMR) data, and was named macrocyclic lactone A21-4. The active compound significantly inhibited the formation of zoosporangia and zoospore and germination of cyst of P. capsici at concentrations lower than $0.0625{\mu}g/ml$. The effective concentrations of the macrocyclic lactone A21-4 for $ED_{50}$ of mycelial growth inhibition were $0.25{\mu}g/ml,\;0.25{\mu}g/ml,\;0.30{\mu}g/ml \;and\;0.75{\mu}g/ml$ against P. capsici, Pythium ultimum, Sclerotinia sclerotiorum and Botrytis cinerea, respectively.

• The Plant Pathology Journal
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• 제29권4호
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• pp.418-426
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• 2013

Pseudomonas isolates from different crop plants were screened for in vitro growth inhibition of Phytophthora capsici and production of biosurfactant. Two in vivo experiments were performed to determine the efficacy of selected Pseudomonas strains against Phytophthora blight of pepper by comparing two fungicide treatments [acibenzolar-S-methyl (ASM) and ASM + mefenoxam]. Bacterial isolates were applied by soil drenching ($1{\times}10^9$ cells/ml), ASM ($0.1{\mu}g$ a.i./ml) and ASM + mefenoxam (0.2 mg product/ml) were applied by foliar spraying, and P. capsici inoculum was incorporated into the pot soil three days after treatments. In the first experiment, four Pseudomonas strains resulted in significant reduction from 48.4 to 61.3% in Phytophthora blight severity. In the second experiment, bacterial treatments combining with olive oil (5 mL per plant) significantly enhanced biological control activity, resulting in a reduction of disease level ranging from 56.8 to 81.1%. ASM + mefenoxam was the most effective treatment while ASM alone was less effective in both bioassays. These results indicate that our Pseudomonas fluorescens strains (6L10, 6ba6 and 3ss9) that have biosurfactant-producing abilities are effective against P. capsici on pepper, and enhanced disease suppression could be achieved when they were used in combination with olive oil.

• 식물병연구
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• 제28권3호
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• pp.143-151
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• 2022

국내의 고추 포장에서 나타나는 시듦 증상의 원인을 규명하기 위하여 2010년부터 2014년까지 5년 동안 충북 괴산의 고추 재배 포장에서 시듦 증상을 보이는 고추의 발병도를 조사하였다. 조사한 연도에 따라서 시듦 증상에 대한 발병에는 차이가 있었지만, 조사하는 시기가 6월과 7월을 지나 8월이 되면서 발병도가 높게 상승하였다. 이 시기 동안 시듦 증상을 보이는 고추에서 Ralstonia solanacearum이 Phytophthora capsici보다 4배 높은 비율로 분리되었다. 충북 괴산과 경북 안동의 포장에서 2013년과 2014년의 2년 동안 채집한 시든 고추에서 병원균을 분리하여 보아도, 조사한 전체 포장 중의 20.3%에서 R. solanacearum이 분리되었으며, 역병균인 P. capsici는 3.8%의 포장에서만 분리되었다. 시듦 증상이 높은 비율로 나타났던 해에는 평균기온이 높았으며, 고추 풋마름병 예찰 모델로 추정된 풋마름병의 초발생일도 빨라짐을 알 수 있었다. 역병 발생 위험 일수와 실제 시듦 증상 발생 빈도의 결과가 부합하지 않는 것은 재배 현장에서 역병 저항성 품종의 사용이 일반화되어 있기 때문이라고 생각한다. 이런 결과를 통해서 역병 저항성 고추 품종이 재배 현장에 도입된 이후, 포장에서 관찰할 수 있는 시듦 증상의 원인은 P. capsici에 의한 역병보다는 R. solanacearum에 의한 풋마름병이었다.