Singh Jugpreet, Cobb-Smith Della, Higgins Elizabeth, Khan Awais
Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456 USA.
Eastern NY Commercial Horticulture Program, Cornell Cooperative Extension at Hudson Valley Research Lab, Highland, NY 12528 USA.
J Plant Pathol. 2021;103(Suppl 1):131-142. doi: 10.1007/s42161-020-00644-w. Epub 2020 Aug 31.
Fire blight remains a serious threat to commercial apple production in the USA and worldwide. Other diseases and spray damage can result in fire blight-like symptoms that can lead to misdiagnosis and affect disease management strategies. Accurate and timely detection of the fire blight pathogen, , is extremely important to deploy appropriate and timely measures to reduce fire blight epidemics in commercial apple orchards. We tested two commercial lateral flow immunoassays (AgriStrip®, and Pocket Diagnostics kit), Loop mediated isothermal amplification (LAMP), and quantitative PCR (qPCR) to diagnose infected samples in lab and field settings. The AgriStrip® and Pocket Diagnostics kits were able to detect actively growing bacteria up to ×10 cfu/ml bacterial concentration. Pocket Diagnostics kit had less specificity and showed positive tests for in addition to . The LAMP assay showed high specificity for and was able to detect up to ×10 cfu/ml bacterial concentrations. The qPCR assay was also able to detect bacterial cells up to ×10 cfu/ml bacterial concentration with highly specific detection. Grower surveys and comparative cost-benefit analysis indicated that immunoassay kits are less expensive, easier to use, and require less technical expertise for on-site fire blight diagnosis than LAMP and qPCR. However, the choice of a specific diagnostic assay depends on the time, sensitivity, and specificity required for the detection of fire blight and its management.
火疫病仍然是美国及全球商业苹果生产面临的严重威胁。其他病害和喷雾损伤可能导致类似火疫病的症状，进而导致误诊并影响病害管理策略。准确及时地检测火疫病病原体对在商业苹果园中采取适当及时的措施以减少火疫病流行极为重要。我们测试了两种商业侧向流动免疫测定法（AgriStrip®和口袋诊断试剂盒）、环介导等温扩增法（LAMP）和定量聚合酶链反应（qPCR），以在实验室和田间环境中诊断感染的样本。AgriStrip®和口袋诊断试剂盒能够检测细菌浓度高达×10 cfu/ml的活跃生长细菌。口袋诊断试剂盒特异性较低，除了还对呈阳性检测。LAMP测定法对显示出高特异性，并且能够检测细菌浓度高达×10 cfu/ml的细菌。qPCR测定法也能够检测细菌浓度高达×10 cfu/ml的细菌细胞，且具有高度特异性的检测。种植者调查和成本效益比较分析表明，与LAMP和qPCR相比，免疫测定试剂盒成本更低、使用更简便，且现场火疫病诊断所需的技术专业知识更少。然而，具体诊断测定法的选择取决于检测火疫病及其管理所需的时间、灵敏度和特异性。
