实时荧光RT-PCR一步法检测南方菜豆花叶病毒

南方菜豆花叶病毒（Southem bean mosaic virus，SBMV）是我国二类检疫性有害生物，以南方菜豆花叶病毒日本分离物（SBMV-J）总RNA为模板，采用RT-PCR方法扩增病毒外壳蛋白基因及其上游基因的cDNA片断并将其克隆到pMD18．T载体上。序列分析结果表明：SBMV-J cp基因由801个核苷酸组成，编码266个氨基酸，SBMV．J与其它分离物及株系印基因的核苷酸序列同源性为83％-97％，氨基酸序列同源性为86％-97％。由于SBMV各分离物及株系印基因的同源性较低，难于设计出较长的普通PCR引物。通过较短引物设计和TaqMan-MGB探针技术，建立了SBMV的实时荧光RT-PCR一步检测方法。该方法的检测低限是0．16pg，最佳检测总RNA的量是0．16ng。     

实时荧光RT-PCR-步法检测南方菜豆花叶病毒

南方菜豆花叶病毒(Southern bean mosaic virus,SBMV)是我国二类检疫性有害生物,以南方菜豆花叶病毒日本分离物(SBMV-J)总RNA为模板,采用RT-PCR方法扩增病毒外壳蛋白基因及其上游基因的cDNA片断并将其克隆到pMD18-T载体上。序列分析结果表明:SBMV-J cp基因由801个核苷酸组成,编码266个氨基酸,SBMV-J与其它分离物及株系cp基因的核苷酸序列同源性为83%～97%,氨基酸序列同源性为86%～97%。由于SBMV各分离物及株系cp基因的同源性较低,难于设计出较长的普通PCR引物。通过较短引物设计和TaqMan-MGB探针技术,建立了SBMV的实时荧光RT-PCR一步检测方法。该方法的检测低限是0．16 pg,最佳检测总RNA的量是0．16 ng。     

RT-PCR和实时荧光RT-PCR一步法检测大豆中菜豆荚斑驳病毒

针对进口大豆的菜豆荚斑驳病毒(Bean pod mottle virus,BPMV)检测,建立了一步法RT-PCR和一步法实时荧光RT-PCR检测方法.依据BPMV的外壳蛋白编码基因设计了特异引物和特异Taqman探针,特异引物的扩增片段约为500bp,阳性质粒的实时荧光PCR方法的检测下限为20fg/μL,是一步法RT-PCR方法的100倍,检测时间由约8 h缩短至4 h.种脐灰色斑驳的大豆种子BPMV检测呈阳性,种脐黑色斑驳的大豆种子BPMV检测呈阴性.     

应用实时荧光定量RT-PCR高效检测葡萄病毒B

 本研究建立了葡萄病毒B的 SYBR GreenⅠ实时荧光定量RT-PCR(RT-qPCR)检测技术。该技术标准曲线扩增效率102.4%,相关系数0.999,最低检测限达10^-4倍稀释cDNA,灵敏度为常规RT-PCR的100倍。重复性试验组内和组间变异系数分别为0.00%~0.65%和0.02%~2.00%,表明检测稳定性好。该技术对田间葡萄样品检测适用范围广,对枝条和老叶柄检测效果最好,冬季枝条和春夏秋季所有老叶柄样品检出率均为100%,与常规RT-PCR检测结果一致。对于其他季节或部位样品,RT-qPCR检出率(43% ~74%)则普遍高于常规RT-PCR(5% ~71%),特别是春季样品和春夏秋季所有嫩叶样品,检出率比常规RT-PCR分别高31% 和38%。对来自我国13个省21个品种的52份田间葡萄样品检测结果表明, RT-qPCR共检测到6个样品为阳性,检出率11.5%,为常规RT-PCR(检出率5.8%)的2倍。     

应用实时荧光定量RT-PCR高效检测葡萄病毒B

 本研究建立了葡萄病毒B的 SYBR GreenⅠ实时荧光定量RT-PCR(RT-qPCR)检测技术。该技术标准曲线扩增效率102.4%,相关系数0.999,最低检测限达10^-4倍稀释cDNA,灵敏度为常规RT-PCR的100倍。重复性试验组内和组间变异系数分别为0.00%~0.65%和0.02%~2.00%,表明检测稳定性好。该技术对田间葡萄样品检测适用范围广,对枝条和老叶柄检测效果最好,冬季枝条和春夏秋季所有老叶柄样品检出率均为100%,与常规RT-PCR检测结果一致。对于其他季节或部位样品,RT-qPCR检出率(43% ~74%)则普遍高于常规RT-PCR(5% ~71%),特别是春季样品和春夏秋季所有嫩叶样品,检出率比常规RT-PCR分别高31% 和38%。对来自我国13个省21个品种的52份田间葡萄样品检测结果表明, RT-qPCR共检测到6个样品为阳性,检出率11.5%,为常规RT-PCR(检出率5.8%)的2倍。     

玉米褪绿斑驳病毒实时荧光RT-PCR检测方法研究

玉米褪绿斑驳病毒(Maize chlorotic mottle virus,MCMV)是我国对外公布的检疫性有害生物。本研究根据该病毒外壳蛋白基因的保守序列,设计得到特异性引物及Taqman荧光探针,建立了MCMV的实时荧光RT-PCR方法,并对其灵敏度与特异性进行了研究。该方法针对2个不同来源的毒株均能得到典型扩增曲线,而没有从小麦线条花叶病毒、玉米粗缩病毒和玉米矮花叶病毒的RNA得到扩增曲线,表明引物与荧光探针具有良好的特异性。针对玉米褪绿斑驳病毒RNA不同稀释度样品,实时荧光RT-PCR检测低限达到10-5稀释度,检测灵敏度要比普通RT-PCR高出100倍。因此,本研究建立的MCMV实时荧光方法具有特异性强、灵敏度高和快速有效的优点。     

实时荧光RT-PCR一步法检测苹果茎沟病毒

 根据苹果茎沟病毒(ASGV)各分离物外壳蛋白(CP)基因的保守序列,设计并合成1对特异性引物和1条TaqMan-MGB探针,建屯了对ASGV的实时荧光RT-PCR检测方法。TaqMan-MGB探针3'端具有小沟结合分子(Minor groove binder,MGB),提高了探针的Tm值,缩短了探针长度,解决了病毒各分离物之间基因组变异较大、难以找到较长一致的序列来设计探针的困难。该方法的检测灵敏度比常规RT-PCR电泳检测高约10倍,对于ASGV等在果树体内含量较低的病毒尤为适用。此方法快速、灵敏,整个检测过程完全闭管,无需PCR后处理。     

甘蔗黄叶病毒运动蛋白的原核表达和抗血清制备

甘蔗黄叶病毒(Sugarcane yellow leaf virus,ScYLV)属于黄症病毒科(Luteoviridae)、马铃薯卷叶病毒属(Polerovirus),主要由蚜虫传播,能够侵染甘蔗、玉米等多种作物,引发严重的植物病害。本研究将编码ScYLV运动蛋白(Movement protein,MP)的基因连接到pDB-His-MBP原核表达载体上,转化到大肠杆菌菌株Rosetta中,经IPTG诱导,表达分子量大小约为70 kDa的融合蛋白,将纯化后的融合蛋白制备多克隆抗血清。利用western blot检测抗血清的效价为1∶128 000,灵敏度为1∶256,抗血清不与马铃薯卷叶病毒属(Polerovirus)的其它病毒以及黄症病毒属(Luteovirus)病毒发生交叉反应,具有很好的特异性。本文制备的ScYLV MP抗血清可以用于ScYLV的检测,并为深入研究ScYLV与寄主的相互作用等问题提供材料基础。     

实时荧光RT-PCR检测辣椒轻斑驳病毒的初步研究

本研究选取辣椒轻斑驳病毒PMMoV、烟草花叶病毒TMV、黄瓜花叶病毒CMV和马铃薯Y病毒PVY作为试验材料,根据PMMoV衣壳蛋白(CP)RNA的序列特异性位点,设计出Taqman荧光探针及其引物,采用实时荧光RT-PCR技术对PMMoV进行快速检测,同时与ELISA方法进行了灵敏度比较,结果表明：该方法具有较高的灵敏度及较强的特异性,PMMoV检测结果为阳性,TMV、CMV和PVY均无荧光信号,为阴性,灵敏度是传统的ELISA方法的100倍,而且大大缩短了检测时间。该方法快速、准确、灵敏、简便、安全,具有实际应用价值,适用于植物病毒病害的快速检测。     

应用实时荧光定量RT-PCR检测几种食用菌蛋白抗烟草花叶病毒的活性

根据烟草花叶病毒(Tobacco mosaic virus,TMV)外壳蛋白(CP)RNA的特异性序列设计TaqMan荧光探针及其引物,利用实时荧光定量RT-PCR检测食用菌蛋白抗TMV的活性。经食用菌蛋白处理后,TMV病毒汁液中TMV的RNA浓度下降了22.02%~87.93%,传统生物学测定的食用菌蛋白抗TMV的平均枯斑抑制率为10.88%～83.97%;相关性分析表明,实时荧光定量RT-PCR测定的病毒RNA浓度的下降与传统生物学方法测定的平均枯斑抑制率之间呈正相关(r=0.818 8),具有较好的一致性。利用实时荧光定量RT-PCR检测蛋白抗烟草花叶病毒活性的方法,具有特异性好、快速、简便、重复性高的特点,适合于蛋白抗烟草花叶病毒活性的痕量快速高效检测。     

甘蔗黄叶病毒复制酶基因的克隆及序列分析

 The gene of RNA-dependent RNA polymerase (RdRP) was cloned by RT-PCR from Sugarcane yellow leaf virus-Fuzhou isolate (CHN-FJ1) and then cloned into pMD18-T vector. The sequence showed that the fragment comprised 1 212 nucleotides including part gene of ORF1 and ORF2. The ORF2 was involved the RdRP gene consisted of 995 nucleotides and encoded putative protein of 331 amino acids. Compared the nucleo-tide sequence and encoded putative protein of CHN-FJ1 with the other isolates from different countries, they shared the homology above 92.0%. Phylogenetic tree suggested that the sixteen isolates were classified into four types according to the amino acid sequence of the RdRP. One of the groups contained CHN-FJ1 and the other isolates from China, American, Brazil, Australia and Colombia;however, there was the closest relation between CHN-FJ1 and BRA-YL1 isolate from Brazil.     

来源于猕猴桃的柑橘叶斑驳病毒的RT-PCR检测及外壳蛋白基因序列分析

柑橘叶斑驳病毒(Citrus leaf blotch virus,CLBV)为柑橘病毒属(Citrivirus)代表种。本研究采用RT-PCR技术从我国栽培猕猴桃上首次检测到CLBV,总检出率为13.3%。测定了5个CLBV分离物的外壳蛋白基因(coat protein gene,cp)序列,全长均为1 092核苷酸(nt),分离物间cp基因核苷酸和编码氨基酸序列相似性分别为83.2%~99.7%和91.9%~98.9%,这些分离物与新西兰报道的CLBV猕猴桃分离物M3-A核苷酸序列相似性仅为83%左右,与来源于柑橘及近缘种的CLBV分离物cp基因核苷酸序列相似性为84%~86%。在基于该病毒cp基因核苷酸序列的系统进化树中,本研究所测定的CLBV猕猴桃分离物与新西兰报道的除M3-A外的猕猴桃分离物聚在同一组群。研究结果为进一步明确CLBV在我国猕猴桃上的侵染和危害特点及建立该病毒的分子检测技术提供了重要信息。     

藜草花叶病毒外壳蛋白基因的克隆与RT-PCR检测

 The nucleotide sequence of coat protein (cp)gene of Sowbane mosaic virus (SoMV)was determined. The cp gene of SoMV consists of 726 nucleotides and encodes a putative protein of 241 amino acid re-sidues. Sequence comparison showed that SoMV was most closely related to Rubus chlorotic mottle virus compared to other sobemoviruses. A primer pair was designed for the detection of SoMV based upon the determined cp nucleotide sequence. An expected fragment with 510 bp could be obtained from SoMV, while no specific band was observed from the healthy control. The result showed that the RT-PCR assay with the primer pair was suitable for the specific detection of SoMV.     

甘蔗花叶病毒福建分离物外壳蛋白基因的克隆及序列分析

 A fujian isolate of Sugarcane mosaic virus named SCMV-FJ was isolated from infected sugarcane. Cloning and sequence analysis of the coat protein gene of this isolate was carried out. A pair of primers was designed and synthesized based on the nucleotide sequences of coat protein genes of sugarcane mosaic viruses reported. The coat protein gene of SCMV-FJ was amplified from the extracted total RNA of the infected sugarcane by using RT-PCR, and cloned into the pMD18-T vector. The sequencing result indicated that the cloned segment included a 1137 bp open reading frame(ORF) and a 228 bp 3' untranslated region, in which the ORF comprised the whole coat protein and part of the nuclear inclusion b. The nucleotide and the deduced amino acid sequences of the coat protein gene were compared with those of the other isolates or strains of SCMV subgroup reported in GenBank. The result showed that it shares 56.8%-97.1% and 55.3%-99.4% homology in nucleotide and the putative amino acid sequences, respectively, with the highest amino acid homology of 99.4% with SCMV-D. Thus it was identified as a SCMV-D. This experiment provided a rapid, sensitive and relatively inexpensive method for RT-PCR detection of SCMV. At the same time, the cloning of SCMV-FJ coat protein gene provided the foundation for plant gene engineering against SCMV.     

韭葱黄条病毒厦门分离物外壳蛋白基因序列分析及其分组

 本文在测定了侵染厦门古宅大蒜的病毒分离物（LYSV XM）CP基因序列的基础上,进一步从GenBank登录的58个分离物中选取具有代表性的29个分离物建立CP基因核苷酸序列系统进化树。利用该系统进化树明确了LYSV XM与其他分离物间的进化关系,并在前人研究基础上提出一种基于CP基因核苷酸序列的类群分组方法。     

利用实时荧光RT-PCR方法检测番茄环斑病毒和烟草环斑病毒

根据番茄环斑病毒和烟草环斑病毒各分离物CP基因的保守序列分别设计并合成1对引物和1条TaqMan荧光探针,分别建立了ToRSV和TRSV的实时荧光RT-PCR检测方法。该方法具有更加灵敏、特异、快速和简便的特点,在口岸病害检疫中具有广泛的应用前景。     

Elimination of Sugarcane yellow leaf virus from infected sugarcane plants by meristem tip culture visualized by tissue blot immunoassay

Sugarcane yellow leaf virus (SCYLV), a member of the Luteoviridae , is implicated in the sugarcane disease known as yellow leaf syndrome (YLS), which is characterized by yellowing of the leaf midrib followed by leaf necrosis and possible growth suppression. YLS is distributed worldwide and susceptible cultivars are commonly infected with SCYLV. However, not all cultivars infected with SCYLV show symptoms of YLS and some cultivars that show symptoms do so sporadically. Since it is difficult to obtain virus-free plants of susceptible cultivars, it has not been possible to study the factors involved in SCYLV infection nor the effects of infection on plant growth and yield. A tissue blot immunoassay was used to visualize in vivo presence of the virus so that virus-infected and virus-free plants could be distinguished. Meristem tip cultures were used to produce virus-free plantings of six SCYLV-susceptible sugarcane cultivars. Nearly all of the regenerated sugarcane lines remained virus-free over a period of up to 4 years, whether grown in isolated fields or in the glasshouse. Experimental re-infection of the virus-free plants by viruliferous aphids demonstrated that meristem tip culture did not affect susceptibility of sugarcane to SCYLV. Improved diagnosis and production of virus-free plants of SCYLV-susceptible cultivars will facilitate research to quantify the effect of the virus on yield and to analyse the processes involved in disease development.