• 한국균학회지
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• 제51권3호
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• pp.179-190
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• 2023

Grapevine downy mildew, caused by Plasmopara viticola, significantly damages vineyards and is one of the most devastating diseases affecting cultivated grapes worldwide. In this study, we characterized the phenotypic and molecular traits of 11 P. viticola isolates from four grape-growing regions in South Korea. Additionally, we investigated the diversity of pathogenicity among these isolates and conducted an assay to evaluate the response of grape cultivars to P. viticola infection. Lemon-shaped sporangia were identified in the collected isolates, which released zoospores into the suspension at room temperature. Within a few hours of inoculation, the zoospores developed germ tubes. We tested 11 P. viticola isolates for pathogenicity in 845 grape cultivars to screen for grape host resistance to downy mildew infection. Among the tested isolates, JN-9 showed the highest virulence. Grape cultivars displayed varying phenotypic reactions to P. viticola infection: approximately 7% were highly susceptible, 41% were susceptible, 20% were moderately susceptible, 8% were resistant, and 24% exhibited extreme resistance. Phylogenetic analysis based on four genomic regions (internal transcribed spacer 1 [ITS1], actin, beta-tubulin, and cytochrome c oxidase II) revealed a close evolutionary relationship among all the Korean isolates, forming a single monophyletic lineage. Notably, these isolates showed greater similarity to European isolates than to American isolates. This comprehensive study contributes to a deeper understanding of the identity and behavior of P. viticola, which is crucial for developing effective resistance strategies against this pathogen in grape cultivars cultivated in South Korea.

• The Plant Pathology Journal
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• 제21권2호
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• pp.111-118
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• 2005

Weather data for disease forecasts are usually derived from automated weather stations (AWS) that may be dispersed across a region in an irregular pattern. We have developed an alternative method to simulate local scale, high-resolution weather and plant disease in a grid pattern. The system incorporates a simplified mesoscale boundary layer model, LAWSS, for estimating local conditions such as air temperature and relative humidity. It also integrates special models for estimating of surface wetness duration and disease forecasts, such as the grapevine downy mildew forecast model, DMCast. The system can recreate weather forecasts utilizing the NCEP/NCAR reanalysis database, which contains over 57 years of archived and corrected global upper air conditions. The highest horizontal resolution of 0.150 km was achieved by running 5-step nested child grids inside coarse mother grids. Over the Finger Lakes and Chautauqua Lake regions of New York State, the system simulated three growing seasons for estimating the risk of grape downy mildew with 1 km resolution. Outputs were represented as regional maps or as site-specific graphs. The highest resolutions were achieved over North America, but the system is functional for any global location. The system is expected to be a powerful tool for site selection and reanalysis of historical plant disease epidemics.

• The Plant Pathology Journal
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• 제22권1호
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• pp.28-35
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• 2006

Virulence and genetic diversity were studied using 21 isolates of Sclerospora graminicola, the pearl millet downy mildew pathogen collected from major pearl millet growing areas of India. Variability for virulence was determined by inoculating a set of 10 differential hosts with the S. graminicola isolates in a greenhouse. The isolates varied for latent period (6.4 to 11 days), disease incidence (0 to $98\%$), virulence index (0 to 18.7) and oospore-production potential (1 to 4). Among the 21 isolates, Sg 139 (Rajasthan) was the most virulent and Sg 110 (Tamil Nadu) the least virulent. Based on virulence index (disease incidence$\time$slatent $period^{-1}$), the 21 isolates were classified into eight virulence groups. Genetic diversity among isolates was studied using AFLP markers. Based on similarity index of banding pattern, the 21 isolates were clustered into eight genotypic groups. The AFLP groupings, however, did not match with that of the virulence groupings, and these two were found independent. The isolate Sg 139 that remained distinct in both pathogenic and genetic groupings indicated its highly virulent nature. Implications of these results in downy mildew resistance breeding are discussed.

• The Plant Pathology Journal
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• 제15권1호
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• pp.48-52
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• 1999

Ethaboxam is the first proprietary fungicide developed in Korea, registered in 1998 and commercialized in 1999 by LG Chemical Ltd., Korea. It is a derivative of aminothiazole carboxamide and formulated into 25% wettable powder for practical application in fields. Ethaboxam effectively controlled cucumber downy mildew caused by Pseudoperonospora cubensis, potato late blight caused by Phytophthora infestans, and pepper Phytophthora blight caused by P. capsici, and was superior or comparable to the commercial standards, when foliarly sprayed 3∼5 times until dripping off at approximately 7-day intervals during the growing season. Ethaboxam was required at least 125 mg/liter and 250 mg/liter for effective control of cucumber downy mildew, and potato late blight and pepper Phytophthora blight, respectively. There was not phytotoxicity observed o leaves, stems or fruits of cucumber, potato and pepper from any trial.

• 한국유기농업학회지
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• 제19권4호
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• pp.529-541
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• 2011

Bordeaux mixture made with each grade of lime and copper sulfate was tested general property and disease control value. Bordeaux mixture was made by composition of each grade of lime (95%, 80%) with each grade of copper sulfate(98.5%, 95%). Phytotoxicity was evaluated to Bordeaux mixture made with each grade of lime and copper sulfate, and then low grade copper sulfate (95%) was more severely in the grapevine leaf. Bordeaux mixture, made with each grade lime and copper sulfate, were tried to evaluate control effects of downy mildew in field. As a result, Bordeaux mixture (95% of lime and 98.5% of copper sulfate, 6-6) applied 5 times at late in June was showed more effective disease control value than any other trials of Bordeaux mixture. There was no difference in nutrient status of petiole each treatment. But fruit characteristics were shown more slightly improved quality.

• 농약과학회지
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• 제17권4호
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• pp.428-434
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• 2013

오이 노균병의 생물적 방제를 위하여 Bacillus amyloliquefaciens subsp. plantarum CC110균주를 선발하였다. CC110 균주는 $7.5{\sim}55.0^{\circ}C$에서 생육 가능하며 최적 온도가 $36.6^{\circ}C$이고, pH 4.5~9.5범위에서 생육 가능하고 최적 pH는 7.0이었다. CC110 균주가 가장 잘 이용한 탄소원과 질소원은 fructose와 yeast extract이었다. I 플레이트를 이용한 생물검정에서 CC110 균주가 생성한 휘발성 물질에 의하여 오이 노균병이 발생하지 않았고, 무처리에서 13.2% 발생하였다. CC110 균주를 TSB배지에서 배양한 배양액과 배양세포(cell)를 처리하여 실체현미경, 광학현미경과 주사전자현미경으로 관찰한 결과, 전혀 오이 노균병이 발생하지 않았으며 오이 노균병균의 포자낭 형태가 변형되었다.

• 식물병연구
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• 제19권3호
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• pp.188-195
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• 2013

본 연구는 국내 수집 및 아시아채소개발센터 보유 품종인 오이 22종을 이용하여 노균병에 대한 품종별 저항성 정도를 구명하고 우수 품종을 선발하고자 대만 타이난소재 아시아 채소연구 개발 센터에서 수행하였다. 수집 품종에 대한 노균병 병원균 접종은 모든 수집 품종의 생장 단계 중 유엽이 5-6엽 전개되는 유묘 초기에 병원균을 접종하여 검정하였다. 이때 노균병 발병에 최적 발병조건 유지를 위해 온도 조절이 가능한 항온기 내에서 처리 후 일정기간 유지하였다. 노균병균의 접종농도는 $1{\times}10^5$ spores/ml의 포자 현탁액을 오이 잎에 1회 분무 접종 후 잎에 발생한 병반수를 6, 9, 12, 15일 총 4회에 걸쳐 조사하였다. 그 결과 $15^{\circ}C$와 $25^{\circ}C$ 챔버에서는 병반 형성이 매우 낮았으나 $20^{\circ}C$ 처리에서는 처리 품종당 평균 병반수 20-30개(5엽 기준)를 나타내어 병반 형성이 비교적 높았다. 처리 품종별 병반수는 'C-19' 품종에서 0.90(10-20% 미만)로 다른 품종에 비하여 비교적 병반수가 낮아 노균병에 대한 가장 높은 저항성을 나타내었다. 기타 품종에서는 병반수가 다량 형성되어 노균병에 대한 저항성이 낮았으며 처리 후 경과일수가 길어질수록 더욱 증가되어 유의적인 차이는 나타나지 않았다.

• 농업생명과학연구
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• 제46권2호
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• pp.27-33
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• 2012

본 연구는 친환경적으로 시금치 노균병을 방제하기 위하여 식물정유, 길항미생물 및 난황유의 병발생 억제효과를 검정하여 화학농약 대신에 이용할 수 있는 친환경제제로서의 가능성을 검토하였다. 5종의 식물정유 가운데 노균병 방제효과는 1회 처리구와 1주 간격 2회 처리구 모두 Eucalyptus approximans 오일의 병원균 억제효과가 60% 정도로 가장 높은 것으로 나타났다. 반면에 토양에서 선발된 길항균 세 종류의 시금치 노균병 방제효과는 모두 20% 이하로 식물정유 처리보다 낮게 나타났다. 난황유 0.3%와 0.5%농도에서 1주일간격 2회 처리구에서 병원균 억제율이 각각 84.5%와 91.5%로 억제되어 가장 효과가 우수한 것으로 나타났다.

• 한국응용곤충학회지
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• 제26권4호
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• pp.269-272
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• 1987

다이센 수화제와 다이센 M-45, 비침투성 살균제를 공시하여 양귀비 노균병에 대한 약제 방제효과를 포장에서 조사하였다. 상기 다이센계통의 두약제는 타약제에 비하여 노균병의 방제에 효과적이었으며 라텍스 수량을 현저히 증가시켰다.

• The Plant Pathology Journal
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• 제27권2호
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• pp.110-115
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• 2011

Aggressiveness was studied in seven Plasmopara halstedii (sunflower downy mildew) pathotypes: 100, 300, 304, 314, 704, 710 and 714. Aggressiveness criteria including percentage infection, latent period, sporulation density and reduction of hypocotyl length (dwarfing) were analysed in one sunflower inbred line showing a high level of quantitative resistance. Genetic relationships were detected between the seven pathotypes using 12 EST-derived markers. Pathotypes 100, 300, 304 and 314 were characterized with shorter latent period and higher sporulation density than pathotypes 710, 704 and 714. All pathotypes showed high percentage infection values and caused a large reduction in seedling size except for pathotype 314 involved in dwarfing. Pathotypes 714, 704 and 314 had an intermediary genetic position between the pathotypes 100 and 710. No correlation was detected between aggressiveness traits and EST genotypes.