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B.A. Fraaije D.J. Lovell J.M. Coelho S. Baldwin D.W. Hollomon 《European journal of plant pathology / European Foundation for Plant Pathology》2001,107(9):905-917
A multiplex Polymerase Chain Reaction (PCR) assay was developed to detect and quantify four fungal foliar pathogens in wheat. For Septoria tritici (leaf blotch) and Stagonospora nodorum (leaf and glume blotch), the -tubulin gene was used as the target region. Diagnostic targets for Puccinia striiformis (stripe or yellow rust) and P. recondita (brown rust) were obtained from PCR products amplified with -tubulin primer sequences. Final primer sets were designed and selected after being tested against several fungi, and against DNA of infected and healthy wheat leaves. For detection of the four pathogens, PCR products of different sizes were amplified simultaneously, whereas no products were generated from wheat DNA or other non-target fungi tested. The presence of each of the diseases was wheat tissue- and cultivar specific. Using real-time PCR measurements with the fluorescent dye SYBR Green I, PCR-amplified products could be quantified individually, by reference to a standard curve generated by adding known amounts of target DNA. Infection levels for each of the diseases were measured in the flag leaf of 19 cultivars at Growth Stage (GS) 60–64 in both 1998 and 1999. The infection levels for the cultivars were ranked, and showed, with a few exceptions, a good correlation with the NIAB Recommended List for winter wheat, which is based on visual assessment of symptoms. With PCR, the presence of the different pathogens was accurately diagnosed and quantification of pre-symptomatic infection levels was possible. Although sampling and DNA detection methods need further optimisation, the results show that multiplex PCR and quantitative real-time PCR assays can be used in resistance screening to measure the interaction between different pathogens and their hosts at different growth stages, and in specific tissues. This should enable an earlier identification of specific resistance mechanisms in both early-stage breeding material and field trials. 相似文献
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为建立一种方便快捷的检测奶牛隐孢子虫的实时荧光定量PCR(Real-time PCR)方法,根据GenBank中已发表的隐孢子虫18s rRNA基因设计一对引物,并以从卵囊中提取的DNA为模版,初步建立了检测奶牛隐孢子虫的SYBR Green Real-time PCR方法,进而对采集的奶牛粪便进行了特异性、敏感性和重复性检测。结果显示,本研究建立的Real-time PCR方法敏感性高,最低检测阈为10个拷贝的质粒DNA和1g粪便中的10个卵囊,扩增产物的特异性良好,重复性试验的标准差为0.494,重复性良好。研究表明,建立的Real-time PCR快速、特异、敏感,可用于奶牛隐孢子虫病的流行病学调查。 相似文献
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根据GenBank发表的大蒜普通潜隐病毒(GCLV)的外壳蛋白基因的保守序列设计了一对引物,以全基因序列合成的方法获得质粒标准品,以此质粒标准品为模板建立SYBR GreenⅠ实时荧光定量PCR检测GCLV的方法.该方法在4.2×101~4.2×107拷贝之间呈现良好的线性关系,相关系数为0.999,扩增效率为106%,最低可检测42拷贝/PCR反应阳性标准品,比常规PCR敏感100倍;扩增产物的溶解曲线只出现1个单特异峰,无引物二聚体,溶解温度为(77.5±0.9)℃;重复性好,组内变异系数为0.2%~1.1%.用该方法对疑似带病的大蒜材料进行检测,结果表明GCLV-SYBR GreenⅠPCR特异性强,操作简便,敏感性高,可以用于GCLV感染的检测及定量分析. 相似文献
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根据小麦纹枯病菌Rhizoctonia cerealis AG-D融合群ITS区的DNA序列设计特异性引物对WKF-8/WKR-8,对引物的特异性和灵敏性进行检测,建立并优化基于SYBR GreenⅠ荧光染料法的real-time PCR反应体系,绘制标准曲线。检测范围在1.0×10-3~10 ng/μl之间有良好的线性关系,相关系数R2为0.995,扩增效率为99.7%,灵敏度比常规PCR方法高100倍。结果表明,该方法具有快速、特异性强、敏感度高等特点。 相似文献
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利用特殊性引物,应用SYBR Green I实时PCR技术鉴定检测了商业化种植的转基因油菜RT73品系。结果表明,应用实时PCR技术,利用SYBR Green I染料能选择性结合双链DNA的特点,可检测到RT73品系特异性靶序列扩增所产生的荧光信号,且通过溶解曲线确定其熔点值为(80.2±0.5)℃,而对其他油菜品系则检测不到荧光信号。SYBR Green I实时PCR能通过溶解曲线有效地区分了特异性产物、非特异性产物以及引物二聚体,是基因鉴定检测的新方法。 相似文献
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根据GenBank中猪细小病毒VP2基因序列设计特异性的引物,PCR扩增获得猪细小病毒VP2基因片段,并克隆到pMD-18T载体上作为阳性标准品.通过对SYBR Green Ⅰ荧光定量PCR反应条件的优化,建立了猪细小病毒的SYBR Green Ⅰ荧光定量PCR诊断方法,以此为基础研制出试剂盒.试剂盒扩增产物的熔解曲线分析只出现1个单特异峰,无引物二聚体,对PRV、PCV-2、E.coli、CSFV、PRRSV均无阳性信号扩增,可重复性好,测灵敏度可达1.0×101拷贝/μL.结果表明,研制的猪细小病毒SYBR Green Ⅰ实时荧光定量PCR试剂盒具有特异、灵敏、快速、重复性好等优点,适合于猪细小病毒临床样品的检测. 相似文献
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用RT-PCR方法扩增猪流行性腹泻病毒(PEDV)的M基因片段,并克隆到PUC-T载体中,构建含有PEDV M基因片段的重组质粒。以系列稀释后的重组质粒为模板,基于SYBR GreenⅠ进行PEDV检测的实时荧光定量PCR扩增。结果显示,扩增效率为100.4%,相邻扩增曲线之间间距均匀,所有产物的熔解曲线具有单一整齐的峰,标准曲线具有优良的线性关系,最低可准确检测520拷贝/μL的核酸模板,重复性试验的变异系数小于3%。用所建立方法对3种常见猪源RNA病毒的检测结果均为阴性,对临床样品的检出率显著(P0.05)高于常规PCR方法。研究结果表明,建立了一种灵敏度高、特异性强、重复性好的检测PEDV的SYBR GreenⅠ实时荧光定量PCR方法,可用于PEDV的定量检测和猪流行性腹泻的早期快速诊断。 相似文献
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柑橘黑点病是一种严重危害柑橘生产的世界性真菌病害,快速及时地检测出柑橘黑点病病菌(Diaporthe citri)对柑橘黑点病早期诊断和科学防控具有重要的实践意义。本研究基于β-微管蛋白序列,设计柑橘黑点病病菌的特异引物对,基于常规PCR和SYBR Green I实时荧光定量PCR(qRT-PCR)建立了快速分子检测体系,对柑橘黑点病病菌的菌丝和典型带病叶片进行检测验证。结果发现,在常规PCR检测中,该引物可从柑橘黑点病病菌获得244 bp的特异性扩增片段,检测灵敏度达0.78 ng·μL-1;在实时qRT-PCR中,该引物也只有在柑橘黑点病病菌中获得唯一的产物吸收峰,检测灵敏度达0.35 ng·μL-1。利用PCR检测体系对发病黑点叶片进行检测,结果显示,常规PCR的阳性检出率为30%,qRT-PCR的阳性检出率为60%,表明qRT-PCR比常规PCR的灵敏度更高。因此,研究设计的柑橘黑点病病菌特异性引物,以及所建立的常规和实时qRT-PCR检测方法具有速度快、特异性强等特点,可以用于柑橘黑点病病菌的分子鉴定,对病害诊断具有参考价值。 相似文献
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Ramos CA Araújo FR Souza II Bacanelli G Luiz HL Russi LS Oliveira RH Soares CO Rosinha GM Alves LC 《Veterinary parasitology》2011,176(1):79-83
This paper reports a quantitative real-time polymerase chain reaction (q-PCR) based on the msa2c gene and standardized with Platinum SYBR Green/ROX for the detection of Babesia bovis in cattle. The msa2c q-PCR amplified a DNA fragment with average dissociation temperature of 77.41°C (± 0.25°C). No amplification was detected when DNA from B. bigemina, A. marginale or Bos taurus was used as the template. The detection limit of the msa2c q-PCR was 1000 copies per ml of blood sample, with a linear correlation between the number of msa2c copies and threshold cycle. The comparison between msa2c q-PCR and conventional PCR for cytochrome b revealed 88.8% agreement, with a Kappa index of 0.75. In the comparison between msa2c q-PCR and an enzyme-linked immunosorbent assay (ELISA) with semi-purified B. bovis antigen, agreement was 96.3% and the Kappa index was 0.91. The agreement between three tests was 85.8%. The msa2c q-PCR detected a higher number of positive cattle than conventional PCR in an enzootically stable area, but did not differ significantly from ELISA. No significant differences were detected between the three diagnostic tests with cattle from an enzootically unstable area. All animals raised on a tick-free facility were negative for B. bovis in the three tests. These results suggest that msa2c q-PCR is a useful test for the detection of B. bovis infection. 相似文献