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1.
A varied population of cucumber mosaic virus from peppers   总被引:1,自引:0,他引:1  
A varied population of Cucumber Mosaic Virus (CMV) isolates is reported from peppers ( Capsicum annuum ) in Australia. Isolates representing both CMV subgroups (serogroups) I and II have been obtained from the same field at the same sampling time. The CMV isolates were typed into subgroup I (eight isolates) and subgroup II (two isolates) using both a nucleic acid hybridization assay and an immunological assay with monoclonal antibodies. The immunological assay described allows the typing of strains in crude sap extracts, obviating the need for purified virions. The spatial and temporal coincidence of both CMV subgroups presents a situation in which pseudorecombinants with reassorted genomic components might arise.  相似文献   

2.
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   

3.
Antibodies were prepared against two synthetic peptides, P19 and P11, derived from the coat protein N-terminal region of two pepper isolates of Potato virus Y from Tunisia (PVY-P21 and PVY-P2, respectively). The peptides were selected by comparing the predicted amino acid sequences of three pepper and four potato PVY isolates on the basis of their polymorphism and hydrophilicity. Sera with high titres were only obtained against P19. Three MAbs, raised in response to P19, reacted with the homologous virus (PVY-P21) in TAS-ELISA. When tested against a broad range of PVY isolates and related viruses, MAb 3C5 proved to be PVY species specific, whereas MAbs 8A4 and 1D6 reacted specifically with standard isolates of PVYO, PVYC and PVYN-W strains, but not with other PVY isolates. Consequently, epitope(s) recognized by 8A4 and 1D6 MAbs may be specific to a PVY group comprising all serologically PVYnon–N isolates. Surprisingly, and unlike isolate PVY-P21, many Tunisian field pepper isolates did not carry this epitope(s), thus revealing serological heterogeneity within the PVY pepper group. As PVY is one of the most economically important plant pathogens in a range of crops, including pepper, these MAbs will provide a useful tool for practical diagnosis and strain identification of PVY.  相似文献   

4.
 本文对枯萎病菌侵入黄瓜不同抗性品种的途径,以及黄瓜受侵染根部维管组织的变化进行了观察。分生孢子在幼根表皮上萌发产生菌丝,通过胞间层侵入表皮细胞,之后菌丝继续向内部生长,穿过皮层组织进入导管。受侵染的导管内相继出现壁覆盖物、侵填体及褐色物。抗病品种的壁覆盖物比感病品种的厚:侵填体由受侵染导管旁边的薄壁细胞产生,一个细胞可产生多个侵填体,并在侵填体中观察到细胞核的存在,感病品种中的侵填体发育不充分,抗病品种中的侵填体能完全堵塞导管;谒色物在感病、抗病品种中均能完全堵塞导管,对菌丝的侵入构成了较强的机械障碍。  相似文献   

5.
Characterization of cucumber mosaic cucumovirus isolates in Greece   总被引:3,自引:0,他引:3  
Since 1990, massive cucumber mosaic cucumovirus (CMV) outbreaks of various symptomatology, especially on tomato, have been observed all over Greece. To characterize local virus populations, 40 CMV isolates of different origin and symptomatology in the field and glasshouse were examined for subgroup identification and presence of satellite RNA (satRNA). The IC-PCR method was used to amplify part of the coat protein gene of the isolates; the products were submitted to RFLP analysis using Eco RI and Msp I restriction enzymes. Most isolates gave the characteristic pattern attributed to CMV subgroup I, confirming the results obtained by serotyping with monoclonal antibodies. Some Greek isolates, however, possessed additional Eco RI and Msp I sites unusual for subgroup I isolates, and the patterns obtained, especially for Msp I, could be confused with those of subgroup II. These data suggest that restriction enzyme analysis of amplified PCR products used for strain characterization needs to be treated with caution, especially for viruses such as CMV showing genomic heterogeneity. IC-PCR was also developed for satRNA amplification and the results agreed with those of molecular hybridization with a dig-DNA probe. A satRNA was carried by 77% of the isolates.  相似文献   

6.
Four mouse monoclonal antibodies (MAbs) against potato virus Y (PVY) were produced. MAb 4C1 reacted with four isolates of PVYNTN and only very weakly with one isolate of the necrotic strain of PVY (PVYN). It did not react with other isolates of the ordinary strain of PVY tested. MAb 2C9 reacted with all isolates tested and can be used to produce a specific diagnostic kit for routine PVY detection. Other MAbs had different specificities and reacted with isolates of various strains of PVY. MAbs did not react with seven other members of the Potyvirus group including potato virus A. A MAb-based ELISA, using MAb 4C1, was devised and shown to detect PVYNTN specifically.  相似文献   

7.
Chu FH  Chao CH  Peng YC  Lin SS  Chen CC  Yeh SD 《Phytopathology》2001,91(9):856-863
ABSTRACT To clarify the serological relationship of Peanut chlorotic fan-spot virus (PCFV) with other tospoviruses, antisera were produced against the nucleocapsid (N) proteins of this virus and tospoviruses from four serogroups including Tomato spotted wilt virus (TSWV), Impatiens necrotic spot virus (INSV), Groundnut ringspot virus (GRSV), and Watermelon silver mottle virus (WSMoV). In immunodiffusion tests, the antisera only reacted with their homologous antigens. Similar results were noticed in indirect enzyme-linked immunosorbent assay and immunoblot tests, with the exception that strong cross-reactions were observed in heterologous combinations between TSWV and GRSV. The results indicated that the N protein of PCFV is not serologically related to those of the tospoviruses from the four serogroups. To further characterize the virus, viral S double-stranded RNA was extracted from PCFV-infected Chenopodium quinoa and used for cDNA cloning and sequencing. The full-length viral strand of the S RNA was determined to be 2,833 nucleotides, with an inverted repeat at the 5' and 3' ends and two open reading frames in an ambisense arrangement. The 3'-terminal sequence (5'-AUUGCUCU-3') of the viral S RNA is identical to those of other tospoviruses, indicating that PCFV belongs to the genus Tospovirus. The N and the NSs proteins of PCFV share low amino acid identities (22.3 to 67.5% and 19.3 to 54.2%) with those of reported tospoviruses, respectively. The phylogenetic dendrogram of the N gene of PCFV compared with those of other tospoviruses indicates that PCFV is distinct from other tospoviruses. In hybridization analyses, an N gene cDNA probe of PCFV did not react with viral RNAs of TSWV, GRSV, INSV, and WSMoV, and vice versa. Thus, based on these results, we conclude that PCFV is a new tospovirus species.  相似文献   

8.
Sixteen Plum pox virus (PPV) isolates from several stone fruit cultivars, host species, orchards and geographical areas of Bosnia and Herzegovina were selected for typing, using serotype-specific monoclonal antibodies (MAbs) and PCR–RFLP, targeting the 3' terminal region of the coat protein (CP) and P3-6K1 with restriction enzymes Rsa I and Dde I. Four PPV isolates were identified as PPV-M by serology and PCR; eight isolates were identified as PPV-D based on PCR–RFLP on both genomic regions, but were not recognized by the D-specific MAb4DG5. Four isolates from plum were identified as natural D/M recombinants (PPV-Rec), based on conflicting results of CP and P3-6K1 typing. To investigate the genetic diversity of Bosnian PPV isolates in more detail, five isolates (three PPV-Rec, one PPV-M and one PPV-D) were partially sequenced in the region spanning the 3' terminal part of the NIb gene and the 5'-terminal part of the CP gene, corresponding to nucleotides 8056–8884. Nucleotide sequence alignment of recombinant isolates showed that they were closely related at the molecular level to previously characterized recombinants from other European countries, and shared the same recombination break point in the 3' terminal part of the NIb gene. This is the first report of naturally infected Prunus trees with PPV-M, PPV-D and PPV-Rec in Bosnia and Herzegovina. The high variability of the Bosnian PPV isolates fits with the presence of this virus in the country over a long period.  相似文献   

9.
1988~1995年对福建西番莲病毒病的发生为害进行调查,发现在西番莲栽培区病毒病普遍发生,发病率通常在30%~40%,严重的达90%以上。田间症状主要表现为叶片环斑、皱缩、花叶、环斑花叶,死顶和果实木质化等。从田间病株采集40份样本,经电镜观察和采用A蛋白夹心ELISA(PAS-ELISA),用西番莲木质化病毒(PWV)、西番莲黄花叶病毒(PFYMV)、紫果西番莲花叶病毒(GMV)、烟草花叶病毒(TMV)及黄瓜花叶病毒(CMV)的抗血清进行测定,其中36个样本检测出CMV,表明福建西番莲病毒病的主要病原为CMV。与此同时,对西番莲上CMV进行亚组鉴定,采用鉴别寄主和单、多克隆抗体双夹心ELISA(DAS-ELISA)对36个CMV阳性样本进行测定,结果35个属CMV亚组Ⅰ,1个属CMV亚组Ⅱ,表明田间以CMV亚组Ⅰ分离物占绝对优势。  相似文献   

10.
 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   

11.
12.
Polyclonal antibodies were produced against sonicated and heat-killed cells of Pseudomonas syringae pv. pisi strain UQM551 and Pseudomonas syringae pv. syringae strain L, and their specificities were compared. Evidence is presented that the serological specificity between these two pathovars lies in surface antigens. Of the surface antigens purified and tested, only flagella and lipopolysaccharide from the cell wall showed no cross-reactivity with heterologous antisera. Antisera to glutaraldehyde-fixed flagella of the two strains showed a high level of specificity. At a species or genus level, antisera prepared from heat-killed cells of P. syringae distinguished this species from all other bacterial species and genera tested, including strains of Pseudomonas fluorescens, Escherichia coli, Agrobacterium and Rhizobium.  相似文献   

13.
14.
黄瓜花叶病毒2个分离物的亚组鉴定及株系分化研究   总被引:9,自引:0,他引:9  
 基于黄瓜花叶病毒甜菜分离物CMV-XJ1和CMV-XJ2独特的生物学特性,利用RT-PCR对接种寄主植物进行了检测。RT-PCR产物的RFLP结果显示,2个病毒分离物的MspⅠ酶切图谱与CMV亚组Ⅰ病毒的酶切图谱很相似,但经EcoRⅠ酶切后出现显著差异;进一步对2个分离物的外壳蛋白基因进行了克隆,序列分析表明,CMV-XJ1和CMV-XJ2归属CMVIB亚组,二者存在着株系分化的趋势。  相似文献   

15.
A mechanically transmissible virus was isolated from a naturally infected alfalfa plant ( Medicago sativa ) in Karaj, Iran. It induced fern-leaf symptoms in Lycopersicon esculentum , general chlorosis and stunting in Arachis hypogoea , local lesions and systemic infection in Chenopodium quinoa , Phaseolus vulgaris and Vigna unguiculata but only local lesions in C. amaranticolor . In gel-immunodiffusion tests, it reacted strongly with an antiserum to peanut stunt cucumovirus (PSV), moderately with two of six antisera to cucumber mosaic cucumovirus (CMV) and with two of five antisera to tomato aspermy cucumovirus. Its spherical virions (28 nm in diameter) contained a coat protein of approximately 29 kDa and encapsidated four species of RNAs with similar electrophoretic mobilities to RNAs 1–4 of CMV strains Fny and LS and those of PSV strains J and W. Its encapsidated RNAs hybridized in slot-blot hybridization assay with the complementary DNA probe of PSV-W RNAs but not with those of CMV strains. Therefore, on the basis of biological, serological and physico-biochemical properties, the virus was identified as PSV. No satellite RNA was associated with the virus. This is the first report of PSV in Iran.  相似文献   

16.
 采用抗原直接包被和双抗体夹心酶联免疫吸附测定法(ELISA)对采自云南、福建、湖南烟区烟草花叶病样品进行了病毒种类检测,利用三抗体夹心ELISA对黄瓜花叶病毒(Cucumber mosaic virus,CMV)的亚组类型进行了鉴定。在云南采集的520个花叶病样品中,烟草花叶病毒(Tobacco mosaic virus,TMV)、CMV和马铃薯Y病毒(Potato virus Y,PVY)总检出率分别为71.74%、55.01%和6.35%;在福建采集的150个花叶病样品中,TMV、CMV和PVY的总检出率分别为94%、24.66%和8.00%;在湖南采集的74个花叶病样品中,TMV、CMV和PVY的总检出率分别为58.11%、51.35%和2.70%。部分样品为2种以上病毒复合侵染。云南、福建和湖南采集的64个CMV阳性样品中,属亚组Ⅰ的样品为57个,占89.1%;属亚组Ⅱ的样品为10个,占15.6%;其中3个样品为亚组Ⅰ和亚组Ⅱ的复合侵染。  相似文献   

17.
ABSTRACT Mixed infections of cucurbits by Cucumber mosaic virus (CMV) and potyviruses exhibit a synergistic interaction. Zucchini squash and melon plants coinfected by the potyvirus Zucchini yellow mosaic virus (ZYMV) and either Fny-CMV (subgroup IA) or LS-CMV (subgroup II) displayed strong synergistic pathological responses, eventually progressing to vascular wilt and plant death. Accumulation of Fny- or LS-CMV RNAs in a mixed infection with ZYMV in zucchini squash was slightly higher than infection with CMV strains alone. There was an increase in CMV (+) strand RNA levels, but no increase in CMV (-) RNA3 levels during mixed infection with ZYMV. Moreover, only the level of capsid protein from LS-CMV increased in mixed infection. ZYMV accumulated to similar levels in singly and mixed infected zucchini squash and melon plants. Coinfection of squash with the potyvirus Watermelon mosaic virus (WMV) and CMV strains increased both the Fny-CMV RNA levels and the LS-CMV RNA levels. However, CMV (-) strand RNA3 levels were increased little or not at all for CMV on coinfection with WMV. Infection of CMV strains (LS and Fny) containing satellite RNAs (WL47-sat RNA and B5*-sat RNA) reduced the accumulation of the helper virus RNA, except when B5*-sat RNA was mixed with LS- CMV. However, mixed infection containing ZYMV and the CMV strains with satellites reversed the suppression effect of satellite RNAs on helper virus accumulation and increased satellite RNA accumulation. The synergistic interaction between CMV and potyviruses in cucurbits exhibited different features from that documented in tobacco, indicating there are differences in the mechanisms of potyvirus synergistic phenomena.  相似文献   

18.
 在生物学检测的基础上,利用酶联免疫检测、非序列依赖性PCR(sequence-independent amp-lification, SIA)对感病番茄进行分子鉴定,表现卷叶和花叶症状的番茄均被黄瓜花叶病毒(Cucumber mosaic virus,CMV)侵染,分离物分别命名为SXFQ(GenBank登录号为JX993914)和FQ(GenBank登录号为JX993912)。为明确其分类地位,对二者外壳蛋白(coat protein, CP)进行克隆和测序分析。应用DNAMAN软件对本课题组前期检测的7个CMV山西分离物、SXFQ、FQ以及其他3个CMV典型分离物CP序列进行比较分析,发现核苷酸和氨基酸序列最大相似性分别为77.1%~100%和81.6%~100%。氨基酸序列系统进化分析表明,9个CMV山西分离物属于CMV亚组I B的2个分支,其中在指示植物上表现较强症状的SXFQ与其他5个分离物为一分支,在指示植物上表现较弱症状的FQ与其他2个分离物为另一分支。对9个山西分离物CP进行亚组分类分析,结果表明其理化性质、稳定性、疏水性与预测结果相近,2个分支的分离物分别出现相近的氨基酸变异和蛋白结构,存在一定规律性。  相似文献   

19.
A range of selected PVY isolates that induce superficial necrosis on potato tubers, originating from several countries, were compared with standard strains of PVA, PVV and PVY. Biological properties (e.g., host range, aphid transmissibility and relationships based on cross-protection between virus isolates) were studied. PVYNN isolates differ from the normal PVYC, PVYN and PVO strains by their ability to infect Capsicum annuum but not Chenopodium amaranticolor and C. quinoa. All PVYNN isolates are transmissible by Myzus persicae , without any significant differences from one standard strain. These additional data confirm that these tuber-necrosing isolates belong to PVY. However, they could be ranged in a homogeneous and distinct group inside the PVYN group, based on the differences revealed in the host range, in addition to the specific ability naturally to induce necrosis on tubers.  相似文献   

20.
S. Marco 《Phytoparasitica》1985,13(3-4):201-207
The detection of potato leafroll virus (PLRV) and beet western yellows virus (BWYV) and their serological relatedness were investigated by the double sandwich ELISA (DS). In both pure preparations and crude plant extracts, an unequivocal detection of each of these viruses was obtained by DS, provided the homologous antisera were used. No detection was achieved when the heterologous antisera were used, although purified virus could be detected when using the heterologous antisera for coating, providing the homologous antisera were used as conjugates. Therefore, for routine screening of BWYV or PLRV infection in plants, the DS method with homologous antisera can be used. However, it does not seem that BWYV infection in potato could be detected by the routine DS aimed for PLRV screening. In immunosorbent electron microscopy, PLRV and BWYV could be easily detected by coating grids with either homologous or heterologous antiserum. This and the possibility of trapping each virus in ELISA plates with the heterologous antiserum indicate serological cross-reactivity between PLRV and BWYV.  相似文献   

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