Characterization of stem rust resistant derivatives of wheat cultivar Amigo

Summary Originally developed for resistance to greenbug derived from Insave rye, Amigo wheat carries two genes for resistance to stem rust. One of these genes is associated with a rye chromosome 1RS segment carrying the Sec-1 protein marker and presumably greenbug resistance. The second gene which is genetically linked to leaf rust resistance is associated with an Agropyron-derived segment. Rust tests in Canada confirmed that these genes were Sr24 and Lr24. In contrast to Agent and certain 3D/Ag derivatives from Dr. E.R. Sears, the Amigo source of Sr24/Lr24 freely recombined with white seed colour during backcrossing.     

Rapid identification of eels <Emphasis Type="Italic">Anguilla japonica</Emphasis> and <Emphasis Type="Italic">Anguilla anguilla</Emphasis> by polymerase chain reaction with single nucleotide polymorphism-based specific probes

ABSTRACT:   Standard molecular techniques, such as sequencing and restriction fragment length polymorphism analysis after polymerase chain reaction (PCR) amplification are relatively complicated, and species identification can take a long time when using such techniques. We established a quick method, using PCR with species-specific TaqMan Minor Groove Binder (MGB) probes based on single nucleotide polymorphism (SNP) to distinguish the two eel species Anguilla japonica and Anguilla anguilla . This method can be used in processed products. Partial sequences of the mitochondrial 16S rRNA gene were compared between A. japonica and A. anguilla to design a primer pair common to both A. japonica and A. anguilla and probes specific to A. japonica and A. anguilla . Different fluorescence intensities were produced in two PCR microtubes each containing A. japonica - and A. anguilla -specific probes for one target sample. We observed the fluorescence intensity of PCR products in microtubes under ultraviolet transillumination, with similar results to those obtained by real-time PCR. Therefore, SNP-based PCR is a powerful tool for identifying materials of processed foods from either A. japonica or A. anguilla .     

Detection of koi herpesvirus DNA in tissues of infected fish

A newly recognized herpesvirus, koi herpesvirus or KHV, causes a lethal disease in common carp, Cyprinus carpio , and its colourful strain known as koi or fancy carp. In this study, we report new outbreaks of the disease, present initial characterization of the KHV genome, and describe assays for detection of KHV DNA in infected cells and tissues of infected fish. Restriction endonuclease (RE) profiles of viral DNA derived from two epidemiologically distinct KHV isolates were identical to each other. Cloned KHV BamHI and SphI DNA probes specifically hybridized to KHV DNA, but not to DNAs derived from a variety of other fish herpesviruses. The KHV DNA probes detected KHV DNA in tissues of experimentally infected koi fish by DNA hybridization. The KHV specific polymerase chain assays (PCR) were developed for rapid detection and confirmation of KHV DNA in tissues of infected fish.     

.基于TaqMan探针的牛布氏杆菌实时荧光定量PCR的特异性鉴定

根据牛布氏杆菌BM28保守序列设计引物和探针,建立了一种快速鉴定牛布氏杆菌的TaqMan实时荧光定量PCR方法。以梯度稀释的含有目的扩增片段的重组质粒作为标准品,进行定量PCR反应。结果显示:5.0×105~5.0×101拷贝范围内定量PCR均有"S"型扩增曲线,检测灵敏度为50拷贝每微升。本研究建立的实时荧光定量PCR方法具有灵敏度高、特异性和重复性好、方便经济的特性,在牛布氏杆菌的检测与鉴定中具有良好的应用前景。     

应用DNA指纹图谱法对湘白猪群体遗传结构的研究

本文采用Ｊｅｆｆｒｅｙｓ小卫星探针３３．６和３３．１５检测了４个湘白猪品系（Ⅰ，Ⅱ，Ⅲ，Ⅳ）和５个亲本品种（大约克、长白、杜洛克、大围子、沙子岭）的ＤＮＡ指纹图谱。根据指纹带型计算了每个群体的相似系数、平均等位基因频率和最低杂合率。４个湘白猪品系的分析结果表明：湘白猪各品系内的相似系数为０．４５－０．４９，接近于欧美引进品种长白猪（０．４８－０．５０），具有较好的遗传纯合性。根据９个品种（系）的群     

16SrRNA寡核苷酸探针原位杂交法在粪便微生物研究中的应用

16SrRNA寡核苷酸探针（以下简称16SrRNA探针）原位杂交法，可简单、快速和准确地对粪便微生物进行定性和定量测定，本文对该方法及其应用作一综述。     

Establishment of TaqMan Real-time PCR Method for Detection of Duck Poxvirus

To establishment a TaqMan Real-time PCR method for detection of duck poxvirus (DPV),we cloned the P4b gene of DPV.The specific primers and probe were designed according to the nucleotide sequence of avipoxvirus available in GenBank.Recombinant plasmid pMD-DPV-P4b was employed as positive standard template for Real-time PCR.By optimization of reaction conditions,a TaqMan Real-time PCR method for detection of DPV was established.The results of specificity test proved this method had no cross-react with other waterfowl vial agents and poxviruses including avian influenza virus,duck flavivirus,duck hepatitis virus,Newcastle disease virus,duck entertitis virus,goose parvovirus,goatpox virus and fowlpox virus.The detection limit of the assay was 1.29×10² copies/μL of viral DNA,which was 100 times higher than that of the routine PCR.Reproducibility test showed that the CVs of intra assay and inter assay were both less than 2%.Above results supported that the assay was suitable for the detection of DPV very well.     

Biotinylated DNA probes for detecting virus Y and aucuba mosaic virus in leaves and dormant tubers of potato

Summary Detection of potato virus Y (PVY) in dormant potato tubers using the enzyme-linked immunosorbent assay (ELISA) has been reported not to be accurate and reliable and it requires breaking of the dormancy of tubers prior to testing. We describe a simple, practical and highly sensitive hybridization method based on the use of biotinylated DNA probes for detecting PVY and potato aucuba mosaic virus (PAMV) in dilutions made of crude extracts of infected potato leaves and dormant tubers. As little as 50 fg of RNA can be detected by this method, and the probes are highly specific for their targets, even in crude plant extracts. The presence of one virus did not interfere with the detection of the other.     

喜树丛枝植原体的分子鉴定及TaqMan探针实时荧光定量PCR检测方法的建立

 为确定在云南文山地区喜树上发生的疑似丛枝病的病原种类及快速检测喜树丛枝病,本研究利用植原体16S rDNA基因通用引物P1/P7和R16F2n/R16R2对感病喜树总DNA进行常规PCR和巢式PCR扩增、克隆和测序,通过系统进化分析,明确了喜树丛枝植原体属于16SrXXXII组。然后根据喜树丛枝病植原体16S rDNA基因保守区域设计并合成特异性引物和TaqMan探针,制备了喜树丛枝病植原体标准质粒,确定了最优引物浓度和最佳探针浓度,制作的标准曲线有极好的线性关系,决定系数(R²)达到0.999,建立的实时荧光定量PCR检测方法能够特异性地检测喜树丛枝植原体。本研究首次明确了喜树丛枝植原体的分类地位,优化和建立了喜树丛枝植原体TaqMan探针qPCR检测方法,为快速检测喜树丛枝病植原体提供参考。     

Csu-miR260转基因水稻插入序列的表达检测

本文以具有抗二化螟性状的Csu-miR260转基因水稻为试验材料, 采用TaqMan探针实时荧光定量PCR (TaqMan RT-qPCR)和茎环实时荧光定量PCR(stem-loop RT-qPCR)分别对Csu-miR260转基因抗虫水稻中Csu-miR260插入序列和剪切形成的amiR260s的表达情况进行了定量检测。发现Csu-miR260插入序列和剪切形成的20 nt和21 nt两种长度amiR260s在转基因抗虫水稻苗期的根、茎、叶中表达, 且无组织表达特异性。该试验解决了人工miRNA作物中amiRNA及前体检测引物的特异性问题, 为人工miRNA植物干扰序列的表达分析提供技术参考, 并为miRNA转基因作物遗传表达相关安全评价提供了数据参考。