Rhizoctonia solani anastomosis group 3 (AG-3) causes several diseases of potato, including black scurf and stem canker, affecting potato production in the Skagit Valley, Washington, and around the world. Primers for a SYBR-Green II-based real-time polymerase chain reaction (qPCR) assay were designed from sequences of the nuclear internal transcribed spacer (ITS) regions of fungal isolates of potato and onion from the Pacific Northwest, USA. The primers preferentially amplified R. solani AG-3 DNA, compared to DNA from R. solani AG-4, AG-5 and AG-8. In silico analysis of primer-template duplex stability indicated that the assay also will detect R. solani AG-3 isolates from pea and onion in Washington State and from diverse crop species around the world, but not R. solani AG-9 and AG-2-1. The assay was used to quantify R. solani AG-3 populations in pathogen-infested field soils after temporary flooding rotation, a practice found to be effective for reducing Sclerotinia sclerotiorum and R. solani AG-3 in potatoes in growth chamber studies. Population densities of the pathogen were not significantly reduced in saturated (flooded) soils relative to fallow. However, the qPCR approach was more sensitive and quantitative than the toothpick baiting method for diagnosis of these soil samples. Accurate detection and quantification of R. solani AG-3 in soil will facilitate the development of integrated management plans for Rhizoctonia diseases of potato.

中文翻译：

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实时PCR定量土壤样品中的茄根丝菌AG-3。

solani吻合菌第3组（AG-3）引起马铃薯的几种疾病，包括黑皮屑和茎枯萎病，影响了斯卡吉特山谷，华盛顿以及世界各地的马铃薯生产。从美国西北太平洋地区的马铃薯和洋葱真菌分离株的核内转录间隔区（ITS）区域序列设计用于基于SYBR-Green II的实时聚合酶链反应（qPCR）分析的引物。与来自solani solani AG-4，AG-5和AG-8的DNA相比，引物优先扩增solani solani AG-3 DNA。对引物-模板双链体稳定性的计算机分析表明，该检测方法还将检测华盛顿州豌豆和洋葱以及世界各地不同农作物物种中的茄状R. solani AG-3分离株，但茄状R. solani AG-9和AG- 2-1。该测定法用于定量R。临时淹没轮作后，病原体侵染的田间土壤中的solani AG-3种群有效，在生长室研究中，这种做法可有效减少马铃薯中的核盘菌和R. solani AG-3。相对于休耕，在饱和（淹没）的土壤中病原体的种群密度并未显着降低。但是，qPCR方法比牙签引诱方法对这些土壤样品的诊断更为灵敏和定量。正确检测和定量土壤中的茄枯萎病菌AG-3将有助于制定马铃薯根瘤菌病综合管理计划。相对于休耕，在饱和（淹没）的土壤中病原体的种群密度并未显着降低。但是，qPCR方法比牙签引诱方法对这些土壤样品的诊断更为灵敏和定量。正确检测和定量土壤中的茄枯萎病菌AG-3将有助于制定马铃薯根瘤菌病综合管理计划。相对于休耕，在饱和（淹没）的土壤中病原体的种群密度并未显着降低。但是，qPCR方法比牙签引诱方法对这些土壤样品的诊断更为灵敏和定量。正确检测和定量土壤中的茄枯萎病菌AG-3将有助于制定马铃薯根瘤菌病综合管理计划。