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1.
In 1983 and 1987/88 two limited outbreaks of zucchini yellow mosaic virus in cucumber and zucchini squash occurred in the Westland glasshouse district in the Netherlands, mainly in glasshouses. The disease could be eradicated and has not recurred so far. In both cases a relatively mild but still highly pathogenic strain of the virus was involved. Diseased plants of zucchini yielded severely distorted or no fruits and it was difficult to obtain seeds from infected plants. Two out of 4196 seedlings grown in isolation from seed from inoculated zucchini plants showed symptoms and contained the virus, indicating that the virus can be transmitted via seed but at very low rate. This explains the erratic incidence and international distribution of the virus.  相似文献   

2.
为明确苹果茎沟病毒(apple stem grooving virus,ASGV)柑橘碎叶株系(citrus tatter leaf virus,CTLV)在中国柑橘产区的发生分布及其分子特性,于2017—2021年对我国12个柑橘主产区开展系统调查,并采用多重比对以及系统发育分析法对CTLV的全序列进行分析。结果表明,从12个柑橘主产区采集的2 012份疑似样品中检测出413份感CTLV阳性样品。除陕西省外,其余11个柑橘主产区样品中均检测出CTLV,并且柚类样品中CTLV的检出率最高,达到32.31%。对分离获得的22株CTLV毒株和已知的7株CTLV以及5株ASGV毒株进行全序列分析,发现所有34株毒株的核苷酸序列相似性为78.6%~99.8%,且CTLV序列的保守性较高。此外,与其他4株ASGV毒株相比,本研究中22株CTLV毒株与ASGV-MK毒株(GenBank登录号为MZ127820.1)具有更近的亲缘关系。推测CTLV中国毒株间的亲缘关系可能与其采样地和寄主品种有关。  相似文献   

3.
兰花斑点病毒是一种主要由加州短须螨传播的弹状或杆状的兰花病毒,会导致兰花产生褪绿斑或坏死斑症状。其分布包括亚洲、欧洲、大洋洲、美洲和非洲,能够侵染50种以上的兰花。它广泛的分布和寄主范围对世界兰花产业有巨大的危害性,而国内尚缺乏对兰花斑点病毒的系统研究。本文主要从传统生物学和分子生物学等方面对兰花斑点病毒进行简要评述,并探讨了它的检疫重要性。  相似文献   

4.
Actinidia chinensis and A. deliciosa plants from China, showing a range of symptoms, including vein clearing, interveinal mottling, mosaics and chlorotic ring spots, were found to contain ~300 nm rod-shaped virus particles. The virus was mechanically transmitted to several herbaceous indicators causing systemic infections in Nicotiana benthamiana, N. clevelandii, and N. occidentalis, and local lesions in Chenopodium quinoa. Systemically- infected leaves reacted with a Tobacco mosaic virus polyclonal antibody in indirect ELISA. PCR using generic and specific Tobamovirus primers produced a 1,526 bp sequence spanning the coat protein (CP), movement protein (MP), and partial RNA replicase genes which showed a maximum nucleotide identity (88%) with Turnip vein clearing virus and Penstemon ringspot virus. However, when the CP sequence alone was considered the highest CP sequence identity (96% nt and 98% aa) was to Ribgrass mosaic virus strain Kons 1105. The morphological, transmission, serological and molecular properties indicate that the virus is a member of subgroup 3 of the genus Tobamovirus.  相似文献   

5.
 本研究合成了苹果茎沟病毒(ASGV)、苹果褪绿叶斑病毒(ACLSV)和苹果茎痘病毒(ASPV)的生物素标记cDNA探针,对斑点杂交和免疫印迹杂交检测这3种病毒的效果进行了分析。以含ACLSV和ASGV克隆片段的大肠杆菌菌液为样品时,斑点杂交检测灵敏度分别为80 cfu/μL和50 cfu/μL。以离体培养砂梨植株为材料,采用斑点杂交法检测砂梨离体培养植株粗提液中的3种病毒,均产生强的杂交信号,且特异性好。比较斑点杂交和ELISA检测病毒含量相对较低的热处理再生植株中ASGV和ACLSV,结果表明斑点杂交具有较高的灵敏度。组织印迹杂交检测砂梨离体植株ASGV和ACLSV的结果显示,这2种病毒在离体植株的各部位均有分布,自基部至茎尖各部位印迹均产生很强的杂交信号。  相似文献   

6.
7.
梅是一种原产于中国、具有重要经济价值、花果兼用型的树种。在其生长繁育过程中易受病毒等病原侵染,从而可能造成严重的经济损失。目前我国梅树上病毒的发生及分布尚不清楚。为此,对无锡、武汉、上海、杭州、南京的梅园进行了调查,采集了115份样品,其中发现了疑似病毒病害,主要症状表现为花叶、卷叶、叶片皱缩、褪绿、脉间失绿等。RT-PCR检测出了苹果茎沟病毒(ASGV)、樱桃病毒A(CVA)和亚洲李属病毒2(APV 2),检出率分别为30.4%、4.3%和3.5%。此外,克隆了这三种病毒的外壳蛋白基因序列,同GenBank已登录的相应序列相似性为86%~99%(核苷酸水平)和83%~99%(氨基酸水平)。序列比较发现APV2梅分离物与日本梅分离物亲缘关系较近。  相似文献   

8.
三种ELISA方法检测苹果褪绿叶斑病毒和苹果茎沟病毒的比较   总被引:19,自引:1,他引:18  
苹果褪绿叶斑病毒(ACLSV)和苹果茎沟病毒(ASGV)是感染苹果和其它一些果树的重要病毒。作者应用PAS-ELISA法成功地检测了苹果组培苗中的这两种病毒。为了简化操作步骤,试验了DAS-ELISA和改良DAS-ELISA法,并与PAS-ELISA的检测结果比较。试验结果表明,DAS-ELISA能检测出ASGV,却不能检测出ACLSV,与此同时,这两种病毒均可用改良DAS-ELISA检测。DAS  相似文献   

9.
A study was carried out to demonstrate that Rice yellow mottle virus (RYMV), a virus known to be transmitted by beetles, can spread between rice plants by direct leaf contact caused by wind. Almost all healthy plants surrounding an infected plant became infected when exposed to a fan blowing for 15 min at a distance of 50 cm. Spread of RYMV by plant contact, mediated by wind, was also demonstrated in field experiments, the extent of spread depending on plant density. Infection was almost 10 times higher in plots with a density of 33 plants m−2 than in plots with 16 plants m−2. Less spread was observed in plots protected by 1·5 m high windscreens. It is suggested that wind-mediated spread of RYMV may result from abrasive contact between leaves of plants.  相似文献   

10.
Potato virus Y (PVY) is responsible for major viral diseases in most potato seed areas. It is transmitted by aphids in a non-persistent manner, and it is spread in potato fields by the winged aphids flying from an infected source plant to a healthy one. Six different PVY strains groups affect potato crops: PVYC, PVYN, PVYO, PVYN:O, PVYNTN, and PVYN-Wi. Nowadays, PVYNTN and PVYN-Wi are the predominant strains in Europe and the USA. After the infection of the leaf and accumulation of the virus, the virus is translocated to the progeny tubers. It is known that PVYN is better translocated than PVYO, but little is known about the translocation of the other PVY strains. The translocation of PVY occurs faster in young plants than in old plants; this mature plant resistance is generally explained by a restriction of the cell-to-cell movement of the virus in the leaves. The mother tuber may play an important role in explaining mature plant resistance. PVY is able to pass from one stem to the other stems of the same plant through the vascular system of the mother tuber, but it is unknown whether this vascular link between stems is permanent during the whole life of the plant. Two greenhouse trials were set up to study the spread of PVY in the vascular system of the potato plant. The PVY-susceptible cultivar Charlotte was used for both trials. It was demonstrated that all stems growing from a PVY-infected tuber will become infected sooner or later, and that PVYN-Wi translocates more efficiently to progeny tubers than PVYNTN. It was also demonstrated that the progressive decay of the mother tuber in the soil reduces the possibility for virus particles to infect healthy stems through the vascular system of the mother tuber. This new element contributes to a better understanding of the mechanism of mature plant resistance.  相似文献   

11.
烟草环斑病毒(Tobacco ringspotvirus,TRSV)是我国公布的二类检疫危险性有害生物,对农业生产危害较大。受该病毒侵染的一些寄主植物出现隐症,并伴随病毒浓度降低,给检测工作造成困难。根据TRSV外壳蛋白基因序列设计合成了一对引物及一条MGB探针,优化了反应条件,建立了TRSV实时荧光RT-PCR检测方法。该方法与常规的DAS-ELISA方法和RT-PCR方法相比,灵敏度分别提高了200倍和4倍,并且对不同寄主上的TRSV均有较好的检测效果。  相似文献   

12.
A putative virus-induced disease of pear (Pyrus pyrifolia var. Hengshen) showing symptoms of reduced size of foliage and leaf distortion was observed in orchards in central Taiwan in 2004. The sap of symptomatic leaf samples reacted positively to an antiserum against Apple stem grooving virus (ASGV). Two virus cultures, designated as TS1 and TS2, were isolated from symptomatic pears. Flexuous filamentous virions of ∼ 12 × 600 nm were observed in symptomatic pear leaves and purified virus preparations. Results of back inoculation of pear seedlings with TS1 revealed that ASGV was the causal agent of the disease. Sequence analyses of the cloned coat protein (CP) genes of TS1 and TS2 shared 88–92.4% nucleotide and 90.7–97.1% amino acid identities with those of other ASGV isolates available in GenBank. The polyclonal antibody generated against ASGV TS1 has been routinely used for the detection of the ASGV-infection in the imported pear scions for quarantine purpose via enzyme-linked immunosorbent assays (ELISAs). One of 1,199 samples of pear scions imported from Japan during 2005–2007 was identified as ASGV-positive and the virus was designated as AGJP-22. The CP gene amplified from this AGJP-22 shared 97.9–98.3% amino acid identities to those of the domestic isolates and they were closely related phylogenetically. To date, these data present for the first time conclusive evidence revealing that ASGV is indeed the causal agent of the pear disease displaying symptoms of reduced size of foliage and leaf distortion in Taiwan.  相似文献   

13.
大麦黄矮病毒-GAV在燕麦植株体内运动规律的初步研究   总被引:2,自引:0,他引:2  
 利用RT-PCR方法研究了大麦黄矮病毒-GAV在燕麦植株内的移动规律。先将介体麦二叉蚜(Schizaphis graminum)在BYDV-GAV新鲜病叶上饲毒,再将获毒蚜虫放置到二叶期的健康燕麦植株接种48h,随后分期提取接种植株的第1~6片叶和根组织的总RNA,利用特异引物扩增BYDV-GAV的外壳蛋白(CP)基因以检测病毒在燕麦植株内的复制和移动。结果表明,在接种5d后,接种叶片(第2片叶)呈现阳性,接种7d后,植株新生的第4片叶被侵染,接种9d后,部分的第3片叶呈现阳性,至接种16d,几乎所有的叶片均呈现阳性。仅在接种的第5、7和9d收集的根组织呈现阳性,而所有的第1片叶均为阴性,可能是由于这些组织内病毒含量太低所致。本研究初步揭示了BYDV-GAV长距离运动的规律并且发现该病毒在燕麦根部从接种到系统发病都没有进行大量增殖,为今后进一步研究病毒运动机制选取适当的植物材料提供了基本信息。  相似文献   

14.
A virus having tubular particles (124, 142 and 167 nm) was manually transmitted from and to Anthoxanthum odoratum (sweet vernal grass). Other experimental hosts were Chenopodium quinoa, C. amaranticolor, Zea mays, Avena sativa and Hordeum vulgare (barley); winter cultivars of barley were more often infected than spring cultivars. In tests which simulated mechanical injury, the virus was transmitted from infected to healthy A. odoratum but not to healthy barley. The virus particles, which were seen as aggregates in the cytoplasm of A. odoratum leaf cells and in anther walls, reacted strongly in immunosorbent electron microscopy tests with antisera to strains of barley stripe mosaic hordeivirus. Nevertheless, the virus could be distinguished from the Type strain of barley stripe mosaic virus by reciprocal serological tests and by symptoms in infected barley cv. Black Hulless. Using an antiserum produced against the virus, a survey of A. odoratum in the field revealed one of 72 tested plants to be naturally infected. The virus is probably that described by Catherall & Chamberlain (1980) and named anthoxanthum latent blanching virus.  相似文献   

15.
A survey was conducted to evaluate the sanitary status of pome fruit trees in Syria during spring 2003 and 2004 in 6 governorates: Damascus, Al-Qunaitara and Al-Sweida (Southern region), Homs and Hama (Central region) and Latakia (Costal Western region), as the main production areas of pome fruits. Leaf samples from 1077 apples, 54 pears and 14 quince were collected and tested for the presence of Apple chlorotic leaf spot virus (ACLSV), Apple stem grooving virus (ASGV) and Apple mosaic virus (ApMV) in 70 commercial orchards and 3 varietal collections by ELISA. Results showed that the virus infection rates were 34 and 2% in apple and pear, respectively. Quince trees were found to be virus tested free. ACLSV was prevailing on apple with 34%, whereas ASGV and ApMV were found in 2 and 0.2% of tested trees, respectively. Pear trees were infected only with ACLSV (2%). 21 apples and 15 pears representative budwood samples were indexed by grafting on the following indicators: (i) Malus pumila cvs. Virginia Crab and Radiant for apple and (ii) M. pumila cv. V. Crab and Pyrus communis cv. Nouveau Poiteau for pear. The virus infection rates by woody indexing were much higher than ELISA, Apple stem pitting virus (ASPV) and ASGV were found in 86 and 82% of apple tested samples, whereas they were 80 and 60% of pear tested samples, respectively. Additional RT-PCR testing carried out for a limited number of samples confirmed the high incidence of ACLSV ASPV, ASGV and the presence of ApMV. This is the first report on pome fruit viruses in Syria, indicating an unsatisfactory sanitary status of the industry. As a consequence, a certification program is recommended for producing locally healthy propagating material.  相似文献   

16.
Tomato chlorosis virus (ToCV) and Tomato infectious chlorosis virus (TICV) are two criniviruses that are emerging worldwide, and induce similar yellowing diseases in tomato crops. While TICV is transmitted only by Trialeurodes vaporariorum , ToCV is transmitted by three whitefly species in two genera Trialeurodes vaporariorum , T. abutilonea and Bemisia tabaci . The efficiency of transmission by T. vaporariorum from plants infected by one virus or by both was compared, and the probability of virus transmission by a single whitefly was derived from group testing experiments. The estimated transmission probabilities ranged from 0·01 to 0·13, and were not significantly different between ToCV and TICV, or between single and mixed infections. Experiments using B. tabaci as a vector and source plants infected by TICV and ToCV did not reveal any functional trans-complementation for transmission of TICV by ToCV, suggesting that if this phenomenon occurs in nature, it is at a very low frequency. Possible reasons why TICV did not establish in southern France while ToCV is now endemic are discussed.  相似文献   

17.
18.
ABSTRACT Isolates of Sweetpotato feathery mottle virus (SPFMV, genus Potyvirus, family Potyviridae) were obtained in several districts of Uganda from sweetpotato plants infected with the sweetpotato virus disease (SPVD), the most important disease of this crop in Africa. A monoclonal antibody (MAb 7H8) raised against the coat proteins (CP) of a mixture of the SPFMV strain C (United States) and the isolate SPV-I (West Africa) distinguished Ugandan SPFMV isolates into those detectable and not detectable by the MAb. These two serotypes differed in prevalence in different districts of Uganda and in two common sweetpotato cultivars. Both serotypes could be transmitted simultaneously by single aphids. The serotypes differed in their ability to systemically coinfect sweetpotatoes that were infected with Sweetpotato chlorotic stunt virus (SPCSV, genus Crinivirus), the virus required to induce SPVD in SPFMV-infected plants. One sweetpotato breeding line, resistant to SPFMV from the New World, was infected by graft-inoculation with all SPFMV isolates from Uganda. Another SPFMV-resistant sweetpotato line became infected with SPFMV and developed SPVD only following coinoculation with SPCSV.  相似文献   

19.
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.  相似文献   

20.
The coat protein gene of the nematode non-transmissible, SP5 isolate of pea early-browning tobravius was replaced with that of the highly nematode transmissible, PPK20 isolate of tobacco rattle tobravirus. Plants were infected with the recombinant virus when mechanically inoculated and the virus invaded the plants systemically. However, although the PPK20 isolate of TRV was transmitted by nematodes from these plants, the recombinant virus was not transmitted. Therefore, the virus coat protein is not the exclusive determinant of nematode transmission.  相似文献   

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