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1.
以克隆ASSVd的部分序列,通过RT-PCR成功合成了地高辛标记的cDNA探针,提取苹果和梨树枝条的总RNA,用斑点杂交技术对其进行了检测试验,结果表明,探针具有很高的灵敏度和特异性。地高辛标记的cDNA探针不与阴性对照枝条RNA以及感染PBCVd、AFCVd、ADFVd枝条总RNA发生杂交,仅与感染ASSVd样品的总RNA杂交。 相似文献
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Ying-Hong He Sayaka Isono Yoko Kawaguchi-Ito Akito Taneda Ken-ichi Kondo Akihiko Iijima Kazuaki Tanaka Teruo Sano 《Journal of General Plant Pathology》2010,76(5):324-330
A 303-nucleotide viroid was isolated from an apple tree (Malus × domestica, ‘Fuji’) cultivated in Japan. The viroid had 84.9% overall nucleotide sequence homology to Apple dimple fruit viroid (ADFVd), a member of Pospiviroidae, reported from Italy. This viroid differed from the Italian variant by 47 mutations (38 substitutions, six deletions and three insertions), and most of these mutations occurred on either side of the central conserved region. The leaves and branches of the infected trees did not have any disease symptoms, but the fruits were dimpled and yellow. The infected scions were top-grafted onto a healthy ‘Fuji’ apple tree, which tested positive for this viroid in a northern hybridization analysis, and yellow dimple fruits were produced in the second growing season. We propose that this viroid is a new variant of ADFVd and causes yellow dimple fruit formation in ‘Fuji’ apple trees. 相似文献
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Ana Peiró Vicente Pallás Jesús ángel Sánchez-Navarro 《European journal of plant pathology / European Foundation for Plant Pathology》2012,132(4):469-475
The use of riboprobes carrying partial sequences of different plant viruses or viroids fused in tandem, has permitted the
simultaneous detection of up to six different pathogens using a non-radioactive molecular hybridization procedure. In the
present report, we describe the development of a unique polyprobe (poly10) with the capacity to detect viruses and viroids
commonly found infecting fruit trees. The poly10 covers eight viruses: Apple mosaic virus (ApMV), Prunus necrotic ringspot virus (PNRSV), Prune dwarf virus (PDV), American plum line pattern (APLPV), Plum pox virus (PPV), Apple chlorotic leaf spot virus (ACLSV), Apricot latent virus (ApLV), Plum bark necrosis and stem pitting-associated virus (PBNSPaV) and two viroids: Hop stunt viroid (HSVd) and Peach latent mosaic viroid (PLMVd). Poly10 is comparable to the individual riboprobes in terms of end-point dilution limit and specificity, allowing
the detection of up to 2.5 picograms of viral or viroidal RNA. However, the polyprobe requires a hybridization temperature
of 60°C instead of the standard 68°C. The validation of the new simultaneous detection strategy was confirmed by the analysis
of 60 field samples, which came from seven different hosts. The use of the polyprobe as an alternative to other routinely
used detection methods is discussed. 相似文献
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Zhixiang Zhang Shan Peng Dongmei Jiang Song Pan Hongqing Wang Shifang Li 《European journal of plant pathology / European Foundation for Plant Pathology》2012,132(1):9-16
This study aimed to develop a polyprobe for the simultaneous detection of four viroids that infect grapevine: Hop stunt viroid (HSVd), Australian grapevine viroid (AGVd), Grapevine yellow speckle viroid-1 and 2 (GYSVd-1, 2), using a non-isotopic dot blot hybridization technique. A polyprobe was constructed by cloning tandem
full-length sequences of HSVd, AGVd and GYSVd-1 into a single vector. The cRNA polyprobe detected all four viroids with similar
sensitivity to that obtained using individual probes. In addition, samples of 78 varieties from Beijing and Xinjiang were
analyzed using the polyprobe to survey the incidence of grapevine viroids in China. The result demonstrated that grapevine
viroids were detected in 56 (71.8%) varieties. In this study, a rapid, reliable and cost-effective approach to the simultaneous
detection of four grapevine viroids has been developed which has the potential for routine use in quarantine and certification
programs. 相似文献
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J. Wang I. N. Boubourakas A. E. Voloudakis T. Agorastou G. Magripis T. L. Rucker P. E. Kyriakopoulou G. Vidalakis 《European journal of plant pathology / European Foundation for Plant Pathology》2013,137(1):17-27
Seventy four percent of the budwood tree sources samples from the Greek national citrus germplasm foundation collection were positive for one or more viroids. Citrus exocortis viroid (CEVd) and Hop stunt viroid (HSVd), the two potentially damaging viroids for the Greek citriculture, especially after transitioning to Citrus tristeza virus resistant/tolerant rootstocks and scions, were detected along with Citrus bark cracking viroid, Citrus bent leaf viroid (CBLVd), and Citrus dwarfing viroid (CDVd). All samples tested negative for Citrus viroid V (CVd-V), CVd-VI and CVd-I-LSS (CBLVd variant). An HSVd isolate related to the non-cachexia variant contained two critical cachexia-related nucleotide changes, while two more isolates were unique among the previously reported HSVds. Unusual CDVd isolates with altered RNA secondary structure were identified in trees additionally co-infected with CEVd and HSVd. Budwood sources that had previously undergone therapy tested negative for all targeted viroids, suggesting that budwood sources in Greece can be protected against graft-transmissible pathogens, even under severe inoculum pressure. Therapied and tested citrus propagative material requires a comprehensive program not available currently in Greece, involving regulators, scientists, and the private sector, for the establishment and successful operation of a national citrus germplasm collection. 相似文献
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A new viroid was detected in hops cultivated in Akita Prefecture, Japan where it is prevalent in many hops fields. In a survey of hop samples collected during the 1986–2002 growing seasons, the new viroid was present in the major Japanese hop-cultivating areas as early as the 1980s. A single-stranded circular RNA of 368–372 nucleotides that assume a highly basepaired, stable, rod-like secondary structure, shares 93%–98% sequence homology with Apple fruit crinkle viroid (AFCVd) isolated from apple and 85%–87% with Australian grapevine viroid (AGVd) isolated from grapevine. Taking into account the present concept of viroid species, we conclude that the viroid is AFCVd. Circumstantial evidence suggests that AFCVd from apples and hops were endemic in Japan only where cultivation of the two host plants overlapped, thereby strongly supporting the possibility that AFCVd (or an ancestral viroid) was transmitted across the species barrier from apples to hops or hops to apples somewhere in the region. Phylogenetic analysis of AFCVd from hops, AFCVd from apples, and AGVd together with the other members of the genus Apscaviroid revealed that the Akita isolates of AFCVd from hops (AFCVd-hop) formed a cluster that is distinct from AFCVd-apple and AGVd. Accumulation of host-specific sequence variation following their isolation in different host species may be leading to the formation of two viroid species from a common ancestor. 相似文献
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Yashika Walia Yogesh Kumar Tanuja Rana Pooja Bhardwaj Raja Ram Pritam Das Thakur Usha Sharma Vipin Hallan A. A. Zaidi 《Journal of General Plant Pathology》2009,75(4):307-311
Apple scar skin viroid (ASSVd) infection is a major limitation to apple fruit quality and causes huge economic losses. In surveys of apple orchards
in the northern Indian state of Himachal Pradesh, fruits with dappling symptoms were noticed. ASSVd was detected from these
fruits and molecularly characterized. Ten clones from three isolates were sequenced, of which seven were new sequence variants
of ASSVd. The clones had significant sequence variability (94–100%) with each other. Variability was more common in the pathogenic
domain of the viroid genome. Four of the clones were 330 nucleotides (nt) long, and the other six had an additional nucleotide.
Phylogenetic analysis showed close affinity of the present isolates with some Chinese and Korean isolates. The study reports
seven new variants of ASSVd and also provides the first molecular evidence of viroid infection (ASSVd) in apple in India. 相似文献
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Liming Lin Ruhui Li Margarita Bateman Raymond Mock Gary Kinard 《European journal of plant pathology / European Foundation for Plant Pathology》2013,137(4):797-804
Asian prunus viruses (APV 1, APV 2 and APV 3), Plum bark necrosis stem pitting associated virus (PBNSPaV) and Peach latent mosaic viroid (PLMVd) are pathogens that infect Prunus species. A single-tube multiplex, TaqMan real-time RT-PCR assay was developed for the simultaneous detection and identification of these pathogens. The protocol includes amplification and detection of a fluorogenic cytochrome oxidase gene (COX) as an internal control. The results of the multiplex TaqMan RT-PCR assay correlated with those from conventional RT-PCR, with a 10-fold increase in sensitivity in the multiplex real-time format. The efficiency and accuracy of the assay was evaluated by testing stone fruit trees from positive control collections and several orchard locations. Several mixed infections of target pathogens were detected in peach orchard samples. This assay is simple, rapid and cost-effective and can be used by quarantine and certification programs where numerous stone fruit trees need to be tested for these pathogens. 相似文献
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F. Ismaeil K. Al-Jabor A. Myrta M. J. Mando E. Al-Saadoun M. Hassan S. Al-Chaabi 《EPPO Bulletin》2006,36(1):65-68
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
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Noémi Van Bogaert Guy Smagghe Martine Maes Mathias De Backer Kris De Jonghe 《European journal of plant pathology / European Foundation for Plant Pathology》2017,149(1):25-33
In Belgium pospiviroids are routinely detected in various hosts. The most frequently found pospiviroids are: Citrus exocortis viroid (CEVd), Chrysanthemum stunt viroid (CSVd), Potato spindle tuber viroid (PSTVd), Tomato apical stunt viroid (TASVd) and Tomato chlorotic dwarf viroid (TCDVd). Apart from the high incidence of pospiviroids in latently-infected ornamentals, viroids have also been found in plants where they cause disease: PSTVd and TCDVd in tomatoes and CSVd in chrysanthemum. In order to gain more epidemiological data on these infections, this study has conducted phylogenetic analyses of Belgian isolates for each of these five pospiviroid species. PSTVd and CEVd-isolates show a clustering depending on host plant identity. This was not observed for TCDVd and TASVd. A very high degree of sequence similarity was noticeable for CSVd-isolates from various hosts. During the past decade, PSTVd and CSVd-infected mother plants have been systematically eradicated in Belgium after positive detection results, also when found in symptomless plants, leading to a decreased trend of these quarantine pests in the past few years. However, other non-quarantine pospiviroid species are still ubiquitously present in many ornamentals. Since these pospiviroids can be equally harmful to crops as the two quarantine pests PSTVd and CSVd, there is still a risk that transmission occurs from symptomless-infected ornamental plants to economically important crops in Belgium such as tomato, pepper and chrysanthemum. 相似文献
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烟台市富士苹果上苹果锈果类病毒分子变异分析 总被引：1，自引：1，他引：0
为明确苹果锈果类病毒(Apple scar skin viroid,ASSVd)在烟台市富士苹果上的变异情况,通过特异性引物对携带苹果锈果类病毒的富士嫩叶进行ASSVd全长扩增,利用生物学软件DNAMAN对所得变异序列进行分析并构建系统进化树。结果表明,从130个样品中筛选到36个阳性样品,36个阳性样品中共克隆获得52条329~333 nt的ASSVd变异序列,其中30个阳性样品含2条或2条以上的ASSVd序列。对所得变异序列进行序列比对发现,同一样品不同克隆间核苷酸序列相似性为94.0%~100.0%,所有变异序列核苷酸序列相似性为94.0%~99.7%,与Gen Bank中来自不同国家或地区的10条ASSVd分离物核苷酸序列相似性为88.3%~99.7%。将序列相似性低于97.0%的12条变异序列进行系统进化分析,结果显示除了333 nt变异序列ZS2-6与伊朗苹果分离物在同一分支外,其余11条变异序列位于同一分支。52条变异序列多序列比对发现,变异位点主要集中在TL区、P区和C区。研究表明烟台市富士苹果上ASSVd存在一定的分子变异。 相似文献
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G. Gambino B. Navarro E. M. Torchetti P. La Notte A. Schneider F. Mannini F. Di Serio 《European journal of plant pathology / European Foundation for Plant Pathology》2014,140(2):199-205
Five viroid species have been reported from grapevine. Hop stunt viroid (HSVd) and Grapevine yellow speckle viroid 1 (GYSVd-1) are distributed worldwide, whereas Grapevine yellow speckle viroid 2 (GYSVd-2), Australian grapevine viroid (AGVd) and Citrus exocortis viroid (CEVd) are found only sporadically. However, the presence of AGVd and GYSVd-2 in several countries, including China, Turkey and Tunisia, suggests a wider dissemination, possibly also in Europe, where AGVd has never been found and GYSVd-2 has been occasionally identified in Italy. Taking advantage of a multiplex RT-PCR assay recently developed for detecting simultaneously these five viroids, vines growing in Italy in commercial vineyards and germplasm collections were surveyed. Besides confirming the widespread presence of HSVd and GYSVd-1 in the field, GYSVd-2 and/or AGVd were identified in two grapevine table cultivars (Sultanina Bianca and Red Globe) from germplasm collections. Tests extended to vines cultivated in southern Italy confirmed the presence of both viroids, which were further characterized. No major sequence divergences between the AGVd and GYSVd-2 variants from Italy and those previously described from other countries were observed. Phylogenetic analysis supported the close relationships among AGVd variants from Italy, Tunisia and Australia. To our knowledge this is the first report of AGVd in Europe and the first molecular characterization of GYSVd-2 isolates from a European country. 相似文献
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J. R. Saucedo-Carabez D. Téliz-Ortiz S. Ochoa-Ascencio D. Ochoa-Martínez M. R. Vallejo-Pérez H. Beltrán-Peña 《European journal of plant pathology / European Foundation for Plant Pathology》2014,138(4):799-805
The total yield of cv. Hass and Mendez avocado trees was evaluated in Grove 1 in Uruapan county: four trees were sunblotch-infected, four asymptomatic (molecularly positive), and four healthy. A further four healthy and four symptomatic trees were evaluated in Grove 2 in Tingambato county. There was a significant 75 % reduction in the total Hass fruit weight from symptomatic trees in Grove 1 (213 kg vs 751 kg in healthy trees) and a 52 % reduction (124 kg vs 255 kg) in Grove 2 (Tukey, p?=?0.05). This reduction was more severe in Mendez: 83 % in Grove 1 (183 kg vs 1,053 kg) and 76 % in Grove 2 (82 kg vs 340 kg). Yield of asymptomatic trees was reduced to 58 % in Mendez and 30 % in Hass. The average weight of 100 fruits was reduced by 13–28 % in Hass and 20–27 % in Mendez in Groves 2 and 1 respectively. The equatorial diameter of 100 symptomatic fruits was 8 % lower in Hass in both groves, and 20–28 % lower in Mendez. The polar diameter decreased by 8–10 % in Hass and 10–11 % in Mendez. The incidence of symptomatic fruits was 46–62 % in Hass and 20–28 % in Mendez. Yield of ASBVd symptomatic Hass and Mendez trees was significantly reduced and fruit morphology negatively affected. 相似文献
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Nemanja Kuzmanović Milan Ivanović Anđelka Prokić Katarina Gašić Nevena Blagojević Joanna Puławska Aleksa Obradović 《European journal of plant pathology / European Foundation for Plant Pathology》2013,137(1):11-16
Crown gall, caused by tumorigenic strains of Agrobacterium spp., is considered one of the most important diseases in stone fruit nurseries throughout the world. Since the crown gall disease has not been studied extensively in Serbia for more than 30 years, the objective of this study was to isolate, identify and characterize the bacterium associated with crown gall symptoms on one-year-old apricot trees. Samples were collected from a nursery in central Serbia and subjected to laboratory analysis. Bacteria were isolated from tumour tissue on yeast mannitol agar (YMA) and six gram-negative isolates were selected for further study. PCR assay using primers specific for virD2, virC, ipt and tms2 pathogenicity-associated plasmid genes revealed that isolates harbour Ti plasmids. All studied strains carrying Ti plasmids were classified as nopaline-type based on further molecular analysis. Using a multiplex PCR assay, targeting 23S rRNA gene sequences, and physiological and biochemical tests, five strains were assigned as A. rhizogenes/biovar 2 and the remaining one as A. tumefaciens/biovar 1. Identity of the strains was confirmed by sequence analysis of the 16S rRNA gene. In pathogenicity assay, all six strains caused tumour formation on inoculated carrot root discs, young tomato and sunflower plants. 相似文献