Eisfeld Carina, Schijven Jack F, Kastelein Pieter, van Breukelen Boris M, Medema Gertjan, Velstra Jouke, Teunis Peter F M, van der Wolf Jan M
Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, Netherlands.
Department of Statistics, Informatics and Modelling, National Institute of Public Health and the Environment, Bilthoven, Netherlands.
Front Plant Sci. 2022 Dec 20;13:1074192. doi: 10.3389/fpls.2022.1074192. eCollection 2022.
is the causative agent of bacterial wilt of potato and other vegetable crops. Contaminated irrigation water contributes to the dissemination of this pathogen but the exact concentration or biological threshold to cause an infection is unknown. In two greenhouse experiments, potted potato plants () were exposed to a single irrigation with 50 mL water (non-invasive soil-soak inoculation) containing no or 10 - 10 CFU/mL . The disease response of two cultivars, Kondor and HB, were compared. Disease development was monitored over a three-month period after which stems, roots and tubers of asymptomatic plants were analyzed for latent infections. First wilting symptoms were observed 15 days post inoculation in a plant inoculated with 5x10 CFU and a mean disease index was used to monitor disease development over time. An inoculum of 5x10 CFU per pot (1.3x10 CFU/g soil) was the minimum dose required to cause wilting symptoms, while one latent infection was detected at the lowest dose of 5x10 CFU per pot (0.13 CFU/g). In a second set of experiments, stem-inoculated potato plants grown were used to investigate the dose-response relationship under optimal conditions for pathogen growth and disease development. Plants were inoculated with doses between 0.5 and 5x10 CFU/plant which resulted in visible symptoms at all doses. The results led to a dose-response model describing the relationship between exposure and probability of infection or illness of potato plants. Cultivar Kondor was more susceptible to brown-rot infections than HB in greenhouse experiments while there was no significant difference between the dose-response models of both cultivars in experiments. The ED for infection of cv Kondor was 1.1x10 CFU. Results can be used in management strategies aimed to reduce or eliminate the risk of bacterial wilt infection when using treated water in irrigation.
是马铃薯和其他蔬菜作物青枯病的病原体。受污染的灌溉水会促使这种病原体传播，但导致感染的确切浓度或生物学阈值尚不清楚。在两项温室试验中，用50毫升不含或含有10⁵ - 10⁹CFU/毫升的水对盆栽马铃薯植株（品种为Kondor和HB）进行单次灌溉（非侵入性土壤浸泡接种）。比较了两个品种Kondor和HB的病害反应。在三个月的时间里监测病害发展情况，之后对无症状植株的茎、根和块茎进行潜伏感染分析。接种5×10⁸CFU的植株在接种后15天首次出现萎蔫症状，并使用平均病害指数来监测随时间的病害发展情况。每盆接种5×10⁸CFU（1.3×10⁷CFU/克土壤）是引起萎蔫症状所需的最小剂量，而在每盆最低剂量5×10⁵CFU（0.13CFU/克）时检测到一例潜伏感染。在第二组试验中，使用在温室中种植的茎接种马铃薯植株来研究在病原体生长和病害发展的最佳条件下的剂量反应关系。给植株接种0.5至5×10⁸CFU/株的剂量，所有剂量均导致出现可见症状。结果得出了一个剂量反应模型，描述了暴露与马铃薯植株感染或发病概率之间的关系。在温室试验中，品种Kondor比HB更易感染褐腐病，而在试验中两个品种的剂量反应模型之间没有显著差异。品种Kondor感染的半数有效剂量（ED）为1.1×10⁸CFU。这些结果可用于管理策略，旨在减少或消除灌溉中使用处理水时青枯病感染的风险。
