首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 812 毫秒
1.
为明确江苏省牡丹上烟草脆裂病毒(Tobacco rattle virus,TRV)的发生情况,利用ELISA和RT-PCR方法对采集自扬州市的40份牡丹叶片样品进行了检测鉴定,测定了其中一个分离物Peony-11中TRV RNA1分子的部分蛋白编码区序列,并结合Gen Bank中已报道的相关序列对其进行了多样性和系统发生分析。结果显示,江苏省扬州市牡丹上TRV的检出率高达62.5%;序列分析表明本研究获得的TRV牡丹分离物Peony-11与Gen Bank中其它63个分离物的核苷酸序列一致率为90.5%~99.7%;系统发生和遗传距离分析表明TRV可以分成2个组10个亚组,组间、亚组间具有较为清晰的地理和寄主特异性,其中Peony-11分离物位于亚组I-1。  相似文献   

2.
香蕉束顶病毒株系生物学特性的研究   总被引:7,自引:1,他引:6  
 在广东香蕉束顶病株症状基本相同的情况下,在8个产区分别随机采集11~15个标样共111个分离物,接种在香蕉苗上,其后又从8个产区的分离物中各选取1个代表分离物用于进行各项研究。寄主范围试验结果,这8个代表分离物可分为能侵染粉蕉的NSP株系(以广州天河分离物为代表的7个分离物)和不能侵染粉蕉的NS株系(高州代表分离物)。用Eco RI对8个毒源地的111个分离物DNA组分1进行酶切分析,结果表明:所有高州分离物共15个和信宜分离物14个中的9个都可以被酶切,应属NS株系;而其余6个毒源地的所有分离物及信宜分离物中的另外5个都不能被酶切,应属NSP株系。在病害潜育期方面,2个株系在大蕉上的差异达到显著水平;在香蕉4个品种上,2株系也存在较明显的差异,但其中有些差异未达到显著水平。在病毒增殖、运转速度及病毒达到高浓度所需的时间上,2个株系也存在显著的差异。  相似文献   

3.
应用肽链图谱和酶联免疫吸附(ELISA)技术,比较了七个黄瓜花中病毒生物学上明确的分离物之外壳蛋白质。所有七个分离物可以归纳为两个亚群,并证实了以往有关这些组群存在的报导。分离物B、C-1、C-2和F属于一个亚群,而分离物L-2、L-3和WL属于另一亚群。同一亚群内的分离物,外壳蛋白表现一致。一维肽链图谱技术看来是种可靠、灵敏的技术,可作为现有病毒分类技术的补充。  相似文献   

4.
腐烂茎线虫种内不同群体形态及遗传分析   总被引:3,自引:0,他引:3  
 对来自国内的13个腐烂茎线虫群体和1个荷兰的鳞球茎茎线虫群体进行了ITS1区的扩增和5种限制性内切酶RsaⅠ、HaeⅢ、MspⅠ、HinfⅠ、AluⅠ的限制性片段长度多态性分析(RFLP),发现13个腐烂茎线虫群体存在2种不同的酶切图谱,2种图谱在RsaⅠ、HaeⅢ、HinfⅠ和AluⅠ4种酶的酶切位点上存在差异,而鳞球茎茎线虫群体的RFLP图谱与腐烂茎线虫的RFLP图谱相比则在全部的5种限制性内切酶的酶切位点上存在差异。根据RFLP酶切图谱的差异,可以将腐烂茎线虫的13个群体分为A、B2种基因型。A基因型包括DeSD1、DeSD2、DeSD3和DeJS14个群体,B基因型包括DeAH1、DeAH2、DeHB1、DeHB2、DeJS2、DeSX、DeSD4、DeTJ1和DeTJ29个群体。对ITS1区的序列进行比对,发现A基因型4个群体的差异在1%~4%之间,B基因型9个群体的差异在0~1%之间,鳞球茎茎线虫与腐烂茎线虫种间的差异在39%~48%之间。对4个腐烂茎线虫群体和1个鳞球茎茎线虫群体进行了形态学上的测量,发现腐烂茎线虫群体的2个基因型间除在4个形态测计值c值、尾长、V值和V'值存在显著差别外,在其它形态测计值上并无显著差异。ITS1区的RFLP图谱和序列比对以及形态测计数据都表明中国的腐烂茎线虫群体存在2种基因型。  相似文献   

5.
 采用黄瓜花叶病毒((CMV)亚组Ⅰ株系Fny-CMV及亚组Ⅱ株系Ls-CMV的RNA2的特定序列片段的cDNA克隆,体外转录,同时掺入32P标记制备负链RNA探针,再与纯化的甜椒上的CMV中国分离物的RNA进行杂交,检测其与探针之间的同源性。共检测样品分离物3份。试验结果表明:河南新乡和北京密云的CMV甜椒分离物与Fny-CMV的核苷酸有高度同源性,隶属于Fny-CMV为代表的亚组Ⅰ株系。来自福建的样品与亚组Ⅱ的Ls-CMV株系有高度同源性,隶属于CMV亚组Ⅱ株系。本试验同时利用源于我国CMV亚组Ⅰ的K株系的RNA2两个EcoR Ⅰ位点间1657-2125 nt的核苷酸序列为探针,同样与以上3份CMV中国分离物进行RNA杂交,进一步比较分析了这几个分离物与我国亚组Ⅰ的K-CMV株系的关系,证明了我国CMV存在亚组与株系分化。  相似文献   

6.
我国不同CMV分离物2b基因片段的RT-PCR扩增及其序列比较   总被引:6,自引:2,他引:6  
 本研究根据黄瓜花叶病毒2b基因的保守序列设计引物,利用一步RT-PCR技术对多个不同寄主和不同地理来源的黄瓜花叶病毒分离物的2b基因片段进行扩增,获得了含该基因全长约90%的cDNA片段(300bp)。序列测定与比较分析结果表明,国内不同CMV分离物2b基因片段核酸序列同源性达93%以上,推测的氨基酸序列同源性超过90%,且均属于亚组Ⅰ。  相似文献   

7.
新疆石河子、伊宁地区黄瓜花叶病毒株系分化   总被引:5,自引:2,他引:3  
为了研究新疆黄瓜花叶病毒(Cucumber mosaic virus,CMV)分子变异及株系分化,对从石河子和伊宁地区采集的205个加工番茄、23个辣椒、4个番茄、2个南瓜样品进行酶联免疫检测和RT-PCR检测.在4种寄主上均检出了亚组Ⅰ型CMV,其中加工番茄的感染率高达74.15%.进一步对来自辣椒的YN-6、LJ-4、L-10,加工番茄的S1-1、S1-14,番茄的YN-2,以及南瓜的YN-9等7个样品CP、RNA3、MP核苷酸序列进行相似性和进化树分析.7个样品与CMV亚组ⅠB株系分离物的相似性较高、亲缘关系最近,均可归为CMV亚组ⅠB.而来自辣椒的LJ-4、L-10与其余5个样品的序列相似性较低,亲缘关系较远,在进化树上形成独立分支.说明在新疆加工番茄及其它蔬菜上广泛流行的CMV存在分子变异.  相似文献   

8.
为明确我国黄瓜花叶病毒株系分化及系统进化基本情况,从湖南、新疆、青海和海南4省区采集1 367个样品对其进行酶联免疫和RT-PCR检测,并对分离获得的15个黄瓜花叶病毒(Cucumber mosaic virus,CMV)纯化分离物CP、MP、2b核苷酸序列进行相似性和进化树分析及生物学性状比较。结果表明,辣椒、龙葵和黄瓜的CMV阳性检出率较高,分别为54.13%、29.19%和18.46%。进化树分析显示CMV-Q5与CMV亚组II的亲缘性较高;CMV-N7为新发现的重组株系,其CP、2b基因属于CMV亚组IB,MP基因却属于CMV亚组II;其余13个分离物均属于CMV亚组IB。CMV-N7和CMV-Q5在系统寄主心叶烟和枯斑寄主苋色藜上引发的症状相似,但比对照株系CMV-P3613(IB)的发病时间要晚1~2 d,系统花叶较温和,枯斑较小。表明在以上4省区常见农作物上广泛流行的CMV存在分子变异。  相似文献   

9.
 采自我国青海、陕西等省地11个寄生小麦的孢囊线虫群体经形态学鉴定为禾谷孢囊线虫(Heterodera avenae)。用PCR技术扩增获得的rDNA-ITS片段长度约为1 060 bp。用Hinf Ⅰ、Taq Ⅰ、Hpa Ⅱ、Hae Ⅲ、Pst Ⅰ、Alu Ⅰ 等6种限制性内切酶酶切ITS扩增产物;青海10群体YBT10A、HY65A、HY61B、ZHZ162B、HY5B、HHX8A、GH132A、HY92A、HY127B、DT142A 的6个酶的RFLP图谱完全一致;陕西YL4A群体的Hae Ⅲ、Hinf Ⅰ和Hpa Ⅱ酶切结果与青海群体的上述3种酶切结果相同,但Alu Ⅰ和 Pst Ⅰ的酶切结果比青海孢囊线虫群体都多1条1 060 bp片段,而YL4A群体Taq Ⅰ酶切结果较为复杂。对比已知Avenae组成员RFLP图谱,青海群体与北京房山H.avenae群体的RFLP图谱一致;而陕西YL4A的Alu Ⅰ图谱与H.avenae法国群体一致,Pst Ⅰ和Taq Ⅰ却与Avenae组成员已知酶切结果均不一致。河南3个禾谷孢囊线虫群体除Taq Ⅰ酶切结果比青海CCN群体多1条520 bp片段以外,其他5种酶的RFLP都一致,而与澳大利亚的禾谷孢囊线虫H.avenae群体的RFLP图谱一致。  相似文献   

10.
采用RT-PCR方法扩增并克隆了2013年湖南省水稻上发生的南方水稻黑条矮缩病毒(Southern rice blackstreaked dwarf virus,SRBSDV)S10片段的近全长序列,采用生物信息学软件Mega、RDP和DnaSP分析其编码的开放阅读框(open reading fragment,ORF)遗传多样性。结果表明:2013年湖南省15个SRBSDV分离物S10编码的ORF序列同源性在99.5%以上,不同分离物中存在3~30个突变位点,绝大部分的核酸突变为无义突变,没有发现可能的重组。在系统发育树上,15个分离物聚类为2个分支,其中湖南汉寿的10个分离物和永州的2个分离物(HuNyz12和HuNyz29)与我国浙江分离物聚为1个亚组、湖南永州的其他3个分离物与我国南部的云南、海南等及越南的分离物聚为1个亚组。系统发育结果表明,SRBSDV随传毒介体白背飞虱迁飞从我国南部向北部扩散。  相似文献   

11.
A RT-PCR was developed for the simultaneous detection and identification of three groups of Pepino mosaic virus (PepMV): European/Peruvian, Chilean 1/US1 and Chilean 2/US2 groups, followed by a restriction analysis that allowed the separation of the European, Peruvian, Chilean 2 and US2 isolates (patent pending). The multiplex RT-PCR reaction was performed by a mix of six primers that amplified a part of the RNA-dependent RNA polymerase gene of PepMV plus an internal control. Amplifications resulted in a 980 bp, 703 bp or 549 bp PCR product for European/Peruvian, Chilean 1/US1 or Chilean 2/US2 groups, respectively. For the identification of the isolates present within the European/Peruvian and Chilean 2/US2 groups, the amplified PCR fragments were directly digested with SacI enzyme. The multiplex RT-PCR method presented higher sensitivity to detect CH1/US1 isolates in field samples than the RFLP-PCR method described by Hanssen et al. (European Journal of Plant Pathology 121:131–146, 2008). The detection limit observed with the multiplex RT-PCR was equal to or 3,125 times higher when compared to single RT-PCR or ELISA-DAS and molecular hybridisation methods, respectively. The use of the multiplex RT-PCR method in routine analysis of field tomato samples allowed the detection of 36.2 and 33.4% more positives when compared to the serological and molecular hybridisation methods, respectively, and the identification of plants infected with one, two or three isolates of PepMV.  相似文献   

12.
Isolates of Rhizoctonia solani AG2-2 obtained from turf with symptoms of large-patch disease of warm-season turfgrasses were compared with known AG2-2 isolates belonging to cultural types IIIB and IV. Some isolates that were previously identified as type IV have been separated here and named LP isolates. Comparisons among isolates were based on cultural morphology, hyphal growth rate, pathogenicity and restriction fragment length polymorphism (RFLP) analysis in the nuclear encoded ribosomal DNA (rDNA) genes. The cultural characteristics of LP isolates varied from those of types IIIB and IV. LP isolates did not show distinct sclerotial formation and zonation, and the colour of their mycelia and pigment deposition was dark brown. LP isolates had slower hyphal growth rates than types IIIB and IV, with an optimum temperature of 25°C compared with 28°C for types IIIB and IV. LP isolates were less virulent on radish but highly virulent on zoysia grass when compared with isolates of types IIIB and IV. Genomic DNA was digested separately with Eco RI, Ban III, Xba I and Sal I, and probed with cloned rDNA from Alternaria alternata in Southern hybridizations. LP isolates had one RFLP pattern, while both IIIB and IV possessed four different patterns each. Cluster analysis of RFLPs showed that R. solani AG2-2 is divided into three genetic subgroups, consisting of the IIIB, IV and LP isolates, respectively. The polymerase chain reaction (PCR) amplified rDNA internally transcribed spacer (ITS) regions of the IIIB, IV and LP isolates had the same length but produced different restriction patterns when digested with Msp I and Taq I. These results indicate that there are three cultural types in R. solani AG2-2, namely IIIB, IV and LP.  相似文献   

13.
Genetic Diversity Within Colletotrichum acutatum sensu Simmonds   总被引:1,自引:0,他引:1  
ABSTRACT Isolates of Colletotrichum acutatum from several hosts were characterized by various molecular methods in comparison with morphological identification. Species-specific primer analysis was reliable for grouping C. acutatum isolates to their designated species. Arbitrarily primed polymerase chain reaction and A+T-rich DNA analyses identified four subgroups within C. acutatum. Subgroup I contained U.S. isolates from almond, apple, peach, and pecan, subgroup II contained isolates from anemone, olive, and strawberry, subgroup III contained isolates from almond (Israel) and strawberry (Spain), and subgroup IV contained a single isolate from anemone (the Netherlands). Likewise, sequence analysis of the internal transcribed spacer (ITS) 2 region alone or the complete ITS (ITS 1-5.8S-ITS 2) region grouped the isolates into the same four subgroups. Percent similarity of the complete ITS region within each cluster ranged from 99.6 to 100.0, 99.8 to 100.0, and 98.6% among subgroups I, II, and III, respectively. DNA sequence analysis of the ITS 2 region alone or the entire ITS 1-2 region was more informative than that of the ITS 1 region, which could only group the isolates into two main clusters. The molecular methods employed for studying genetic variation in populations of C. acutatum determined that this species is diverse, indicating that isolates within populations of each subgroup are not host specific.  相似文献   

14.
ABSTRACT Using a mixture of isolates of Cucumber mosaic virus (CMV) from subgroups I and II as immunogens, 20 mouse hybridoma cell lines secreting monoclonal antibodies were produced. A reliable method for efficient detection and accurate subgrouping of CMV isolates has been developed. Tests with 12 well-characterized strains of CMV and other cucumoviruses demonstrated the presence of epitopes that were virus and subgroup specific. Analyses of 109 accessions of CMV isolates collected from various parts of the world revealed 70% were subgroup I, with 20% identified as subgroup II. Seven isolates (6%) did not react with group-specific antibodies but did react with antibodies that recognized all CMV isolates. Differential reactions among isolates suggested a total of 10 epi-topes were recognized. The antigenic diversity among subgroup II CMVs was greater than for the subgroup I isolates, even though fewer subgroup II isolates were tested.  相似文献   

15.
百合斑驳病毒云南分离物 全基因组序列分析及CP结构预测   总被引:1,自引:0,他引:1  
 对云南嵩明百合上发生的百合斑驳病毒(Lily mottle virus, LMoV)进行全基因组序列测定及分析,并对LMoV嵩明分离物(LMoV-SMi1、LMoV-SMi2)和玉溪分离物(LMoV-YXi1、LMoV-YXi2)外壳蛋白(coat protein,CP)基因进行序列比较,发现云南的LMoV分为2个类群,玉溪分离物属于种群I,嵩明分离物属于种群II。2个类群间的核苷酸和氨基酸同源性分别为86.7%~89.5%、90.1%~92.7%,玉溪分离物和嵩明分离物相比,cp基因发生了3个核苷酸的缺失。对国内外LMoV所有分离物的cp基因氨基酸序列进行系统进化分析,结果表明所有LMoV分离物可划分为2个种群,种群I分离物较种群II分离物几乎均存在1个苏氨酸缺失的差异。此外,对LMoV-SMi2的CP相关特性和空间结构进行了初步预测,认为该蛋白为球状,具有较强的表面可能性,不存在跨膜区域,大多数区域能够形成主要的抗原决定簇,主要集中在aa12-22、aa31-42、aa83-99、aa179-191、aa215-223、aa249-259区段,可作为制备抗血清选择抗原的参考。LMoV-SMi2和LMoV-YXi1在二级结构和三级结构上存在一定的差异,但总体空间结构差异不大。  相似文献   

16.
我国植物青枯菌菌株的遗传多样性和组群划分   总被引:14,自引:0,他引:14  
 采用15条随机引物对我国11个省(市、区)6种不同寄主植物的43个青枯菌代表性菌株和4个国外青枯菌菌株,进行了PCR扩增.引物OPB11、OPA15、OPE1和OPZ10对上述所有菌株扩增获得了相似的产物电泳图谱,分别具1~5条谱带不等;引物OPB7、OPA10和OPF1对马铃薯菌株获得了相同的产物图谱,但对其它寄主菌株的产物间有明显差别;引物OPA14、OPC,6、OPG14、OPF5、OPK14、OPK20和OPK17对于不同菌株的扩增产物多态性很强.供试菌株被聚类为2个组群,即组群A和组群B.组群A中又可分为7个亚组(A1、A2、A3、A4、A5、A6、A7),其中A1含有2个类型(A1-1、A1-2);组群B中也可分为2个亚组(B1、B2),其中B1含有3个类型(B1-1、B1-2、B1-3),B2也含有3个类型(B2-1、B2-2、B2-3).RAPD组群A中包含了27个来自我国不同地区的马铃薯菌株,主要是3号小种、生化变种2;组群B中含有20个来自不同地区、不同寄主的菌株,分属于其它不同的小种和生化变种.研究结果表明,我国青枯菌菌株RAPD组群的划分与菌株的地理来源关系不大,而与寄主来源有明显相关性.此外,通过对我国青枯菌菌株组群进行同源性PCR分析表明,来源自马铃薯的3号小种菌株属于美洲分支"Americanmm",而来自其它寄主的青枯菌1号、5号小种菌株属于亚洲分支"Asiaticum",与本研究RAPD组群A和组群B的划分是一致的.  相似文献   

17.
弯孢类炭疽菌rDNA ITS区的RFLP分析及分类研究   总被引:9,自引:0,他引:9  
 应用核糖体DNA ITS区的RFLP分析对3 8个不同寄主来源的弯孢类炭疽菌菌株的遗传多样性和系统发育进行研究。结果表明:弯孢类炭疽菌的ITS扩增区(ITS4~ITS5)约为650 bp,无长度变异。5种内切酶(Alu I、Bsu RI、Hin 6 I、Hpa Ⅱ和Taq I)的酶切图谱在种内是相似或一致的,而种间差异较大。ITS-RFLP共迁带UPGMA聚类分析的结果表明:3 8个弯孢类炭疽菌菌株被聚为6个类群,群与群之间分界明显,表明种的分界相当明显。ITS-RFLP分析的结果还揭示了一些近似种的分类关系,如,按传统方法分别鉴定为Colletotrichum truncatumC.circinans和C.capsici的许多菌株有相似或完全一致的内切酶酶切图谱,这些分子特征支持它们为同一个种。  相似文献   

18.
 16个芜菁花叶病毒(Turnip mosaic virus,TuMV)欧亚分离物分别来自奥地利、丹麦、德国、匈牙利、尼泊尔和英国6国。利用免疫捕获反转录PCR(Immunocapture RT-PCR,IC-RT-PCR)对16个分离物的HC-Pro(Helper component pro-teinase)基因进行PCR扩增,扩增产物克隆后进行序列测定,HC-Pro基因序列长度均为1374个核苷酸,编码458个氨基酸。16个分离物的HC-Pro基因核苷酸序列同源性为79.5%~99.8%,所编码的氨基酸同源性为94.1%~99.8%。对16个分离物及GenBank上已报道的其它14个TuMV的HC-Pro基因核苷酸的系统进化树分析表明:在16个TuMV欧亚分离物中,除了来自亚洲的分离物N23属Asian-BR组,其余15个来自欧洲的分离物都属于world-B组,其中分离物H1归属world-wide亚组,另外14个分离物则归属New World亚组。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号