• The Plant Pathology Journal
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• 제32권5호
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• pp.431-440
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• 2016

In 2004, bacterial spot-causing xanthomonads (BSX) were reclassified into 4 species-Xanthomonas euvesicatoria, X. vesicatoria, X. perforans, and X. gardneri. Bacterial spot disease on pepper plant in Korea is known to be caused by both X. axonopodis pv. vesicatoria and X. vesicatoria. Here, we reidentified the pathogen causing bacterial spots on pepper plant based on the new classification. Accordingly, 72 pathogenic isolates were obtained from the lesions on pepper plants at 42 different locations. All isolates were negative for pectolytic activity. Five isolates were positive for amylolytic activity. All of the Korean pepper isolates had a 32 kDa-protein unique to X. euvesicatoria and had the same band pattern of the rpoB gene as that of X. euvesicatoria and X. perforans as indicated by PCR-restriction fragment length polymorphism analysis. A phylogenetic tree of 16S rDNA sequences showed that all of the Korean pepper plant isolates fit into the same group as did all the reference strains of X. euvesicatoria and X. perforans. A phylogenetic tree of the nucleotide sequences of 3 housekeeping genes-gapA, gyrB, and lepA showed that all of the Korean pepper plant isolates fit into the same group as did all of the references strains of X. euvesicatoria. Based on the phenotypic and genotypic characteristics, we identified the pathogen as X. euvesicatoria. Neither X. vesicatoria, the known pathogen of pepper bacterial spot, nor X. perforans, the known pathogen of tomato plant, was isolated. Thus, we suggest that the pathogen causing bacterial spot disease of pepper plants in Korea is X. euvesicatoria.

• The Plant Pathology Journal
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• 제26권2호
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• pp.178-184
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• 2010

Four major diseases of chili pepper including two fungal diseases, anthracnose (Colletotrichum acutatum) and Phytophthora blight (Phytophthora capsici), and two bacterial diseases, bacterial wilt (Ralstonia solanacearum) and bacterial spot (Xanthomonas campestris pv. vesicatoria), were investigated under future climate-change condition treatments in growth chambers. Treatments with elevated $CO_2$ and temperature were maintained at $720ppm{\pm}20ppm$ $CO_2$ and $30^{\circ}C{\pm}0.5^{\circ}C$, whereas ambient conditions were maintained at $420ppm{\pm}20ppm$ $CO_2$ and $25^{\circ}C{\pm}0.5^{\circ}C$. Pepper seedlings or fruits were infected with each pathogen, and then the disease progress was evaluated in the growth chambers. According to paired t-test analyses, bacterial wilt and spot diseases significantly increased by 24% (p=0.008) and 25% (p=0.016), respectively, with elevated $CO_2$ and temperature conditions. On the other hand, neither Phytophthora blight (p=0.906) nor anthracnose (p=0.125) was statistically significant. The elevated $CO_2$ and temperature accelerated the progress of bacterial wilt by two days and bacterial spot by one day compared to the ambient treatment. Temperature regime studies of the diseases without changes in $CO_2$ confirmed that the accelerated bacterial disease progress was mainly due to the increased temperature rather than the elevated $CO_2$ conditions.

• The Plant Pathology Journal
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• 제17권5호
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• pp.249-256
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• 2001

Xanthomonas axonopodis pv. glycines 8ra produces a bacteriocin called glycinecinA, which specifically inhibits the growth of bacteria belonging to Xanthomonas species. GlycinecinA was produced by culturing Escherichia coli DH5 containing biosynthetic genes for glycinecinA, and was tested for its control effect against X. vesicatoria on red pepper and X. oryzae pv. oryzae on rice. The bacteriocin activity was much higher in the cell extract than in the supernatant. It reached a maximum level at the stationary phase, ws maintained up to 2 months at room temperature and approximately 10 months at $4^{\circ}$. The optimum concentration of glycinecinA for the control in the greenhouse and in the field was 12,800 AU/ml. In this study, the activity of glycinecinA on rice and red pepper leaves continued for 7-8 days, during which the pathogen populations remained at low levels. Bacterial leaf spot of red pepper and bacterial leaf blight of rice were significantly reduced by the bacteriocin treatments. The control efficacy was as high as, or even higher than, the chemical treatment of copper hydroxide. These results suggest that the bacteriocin is a potential control agent for bacterial diseases.

• 식물병과 농업
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• 제5권2호
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• pp.105-110
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• 1999

Bacterial leaf spot by Xanthomonas campestris pv. vesicatoria has been known to cause serious problem in red pepper in Korea. However recent survey showed that most smptoms in the leaves were mixed with two different symptoms one was leaf spot and the other was canker. bacteria isolated from canker were identified as Clavibacter michiganensis subsp. michiganensis on the basis of biochemical and physiological characteristics. The causal bacteria were non-motile rod-shaped and Gram-positive. The lesions on pepper leaves appeared at first as small blisters or pimple-like white spots which enlarged in size at a later stage. The centers of some of the spots became necrotic and brown and were surrounded by a white halo. Pathogenicity tests were performed on pepper cv. Alchan seedling by spraying of bacterial suspension. During 1997 and 1998 total 17% of 527 fields surveyed were infected by C. michiganensis subsp. michiganensis. The canker of red pepper caused by C. michiganensis subsp. michiganensis was first identified in this study in Korea, and new name "gueyangbyung" was tentatively given to the disease.

• 식물병연구
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• 제24권1호
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• pp.59-65
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• 2018

Pyraclostrobin은 광범위한 스펙트럼의 항진균 활성이 있는 퀴논외부저해제(Quinone outside inhibitor, QoI)로 작용하는 살균제이다. 기존 보고에 의하면 pyraclostrobin이 일부 세균병과 바이러스병에 대해 병 저항성을 유도한다고 알려져 있다. 본 연구는 pyraclostrobin 항진균제를 활용하여 고추 세균점무늬병(Xanthomonas euvesicatoria)의 예방 가능성을 검토하였다. Pyraclostrobin은 in vitro 상에서 X. euvesicatoria에 대해 항균활성이 없었지만, 고추에 pyraclostrobin 단독(방제가 69%) 또는 streptomycin과 혼합 살포(방제가 90%) 하였을 때, 고추 세균점무늬병 예방 효과를 나타냈다. Pyraclostrobin의 고추 세균점무늬병 예방 효과는 병원균 접종 1-3일전이 효과적이었다. 이상의 결과로 pyraclostrobin 살진균제를 활용하여 고추 세균점무늬병을 효과적으로 예방할 수 있을 것을 사료된다.

• 식물병연구
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• 제21권2호
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• pp.89-93
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• 2015

고추 세균점무늬병이 수량에 미치는 영향을 조사하여 경제적 방제수준을 설정하고자 시험을 수행하였다. 노지고추 세균점무늬병 발생정도와 수량과의 회귀식은 Y=-0.724X+281.58, $R^2=0.78$, $r=-0.88^{**}$ 성립하였다. 노지고추 세균점무늬병 발생정도와 수량감소와의 회귀식은 Y=0.813X+15.95, $R^2=0.78$, $r=0.88^{**}$ 성립하였다. 성립된 회귀식을 이용하여 노지 고추 수량에 영향을 주지 않는 수준의 세균점무늬병 방제적기는 발생 발병엽률이 30.3% 이하이었다. 또한 고추 세균점무늬병 경제적 방제수준은 노지 고추 세균점무늬병 발생정도가 16.3% 이하로 결정되었다.

• 식물병연구
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• 제20권3호
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• pp.211-215
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• 2014

본 연구는 파인 오일과 수산화동의 혼용에 의한 고추의 세균성 점무늬병과 탄저병에 대한 방제 효과를 구명하고자 수행하였다. 세균성 점무늬병에 대한 방제 효과는 파인 오일만 단독 처리한 경우 발병엽률 59.6%와 방제 효과 28.9%로 나타났지만 파인 오일과 수산화동을 4:1로 혼용 처리하였을 때 발병엽률 20.0%와 방제효과 76.1%로 가장 효과적이었다. 탄저병에 대한 방제 효과는 파인 오일만 단독 처리한 경우 발병률 79.1%와 방제 효과 7.4%로 나타났지만 파인 오일과 수산화동을 4:1로 혼용 처리하였을 때 발병률 49.9%와 방제 효과 41.7%로 가장 효과적이었다. 이상의 결과는 고추의 세균성 점무늬병과 탄저병의 발병을 파인 오일과 수산화동을 4:1로 혼용 처리함으로서 친환경적으로 방제할 수 있음을 나타낸다.

• The Plant Pathology Journal
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• 제30권2호
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• pp.125-135
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• 2014

A population model of bacterial spot caused by Xanthomonas campestris pv. vesicatoria on hot pepper was developed to predict the primary disease infection date. The model estimated the pathogen population on the surface and within the leaf of the host based on the wetness period and temperature. For successful infection, at least 5,000 cells/ml of the bacterial population were required. Also, wind and rain were necessary according to regression analyses of the monitored data. Bacterial spot on the model is initiated when the pathogen population exceeds $10^{15}cells/g$ within the leaf. The developed model was validated using 94 assessed samples from 2000 to 2007 obtained from monitored fields. Based on the validation study, the predicted initial infection dates varied based on the year rather than the location. Differences in initial infection dates between the model predictions and the monitored data in the field were minimal. For example, predicted infection dates for 7 locations were within the same month as the actual infection dates, 11 locations were within 1 month of the actual infection, and only 3 locations were more than 2 months apart from the actual infection. The predicted infection dates were mapped from 2009 to 2012; 2011 was the most severe year. Although the model was not sensitive enough to predict disease severity of less than 0.1% in the field, our model predicted bacterial spot severity of 1% or more. Therefore, this model can be applied in the field to determine when bacterial spot control is required.

• 식물병연구
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• 제25권2호
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• pp.62-70
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• 2019

The global warming by increased $CO_2$ will effect of plant pathogenic microorganisms and resistance of host plants, and it is expected to affect host-pathogen interactions. This study used Capsicum annuum L. and Xanthomonas euvesicatoria, a pathogenic bacteria of pepper, to investigate interactions between hosts and pathogens in a complex environment with increasedcultivation temperature and drought stress. As a result, the bacterial spot disease of C. annuum L. caused by X. euvesicatoria was $35^{\circ}C$ higher than $25^{\circ}C$. In addition, the effect on water potential on bacterial spot disease was much greater water potential -150 kPa than -30 kPa. The disease progress and severity higher than water potential -30 kPa. This result will useful for understanding interaction with red pepper and X. euvesicatoria under the complex environment with increased cultivation temperature and in water potential -150 kPa drought stress in the future.

• Current Research on Agriculture and Life Sciences
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• 제23권
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• pp.43-51
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• 2005

멕시코와 네팔에서 수집한 고추 유전자원 50점과 이병성 및 저항성 대조품종에 Stemphylium solani와 S. lycopersici 의 혼합접종으로 흰별무늬병(gray leaf spot)에 대한 저항성을 검정하고, 살균제를 살포하여 회복시킨 다음 다시 Xanthomonas campestris pv. vesicatoria를 접종하여 더뎅이병에 대한 저항성을 검정하였다 더뎅이병에는 KC866, KC872, KC902, KC905이 이미 알려진 KC43, KC47, KC220, KC319, KC320, KC380 등과 함께 저항성으로 나타났다. 더뎅이병, bacterial spot)에는 KC897이 이미 저항성으로 보고된 KC177(PI163192)보다 발병이 적어 가장 우수한 것으로 나타났으며 이어서 네팔에서 도입된 KC889, KC896, KC898이 저항성으로 나타났다.