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2005年5月到2006年4月逐月采样,运用一步法RT-PCR检测Citrus psorosis virus(CPV)在Dweet橘橙苗木叶片和枝皮中的分布。保存在控温温室中的Dweet橘橙病株中老叶、老皮、嫩叶和嫩皮全年都可以检测出CPV;保存在网室中的Dweet橘橙病株中老叶、老皮全年均能检测到CPV,而夏梢的嫩叶、嫩皮不能稳定地检测出CPV,春、秋梢的嫩叶、嫩皮均可检测到CPV,表明一步法RT-PCR检测CPV最佳取样部位为老叶和老皮。 相似文献
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A. Bouani M. Al Rwahnih N. Abou Ghanem-Sabanadzovic I. Alami M. Zemzami A. Myrta V. Savino 《EPPO Bulletin》2004,34(3):399-402
Field surveys were carried out in the main stone-fruit growing areas of Morocco to evaluate the sanitary status of commercial orchards, varietal collections and nurseries. The presence of virus and virus-like diseases was checked by ELISA, sap transmission to herbaceous hosts, testing on woody indicators and molecular hybridization (dot-blot and tissue-printing). 1211 samples (382 almond, 339 peach, 291 plum, 150 apricot and 49 cherry) were tested by ELISA for the presence of Prunus necrotic ring spot virus (PNRSV), Prune dwarf virus (PDV), Apple chlorotic leaf spot virus (ACLSV), Apple mosaic virus (ApMV) and Plum pox virus (PPV). The overall average of virus infection rate was 16.4%, whereas that of single species was: 22.6% for almond, 17.8% for plum, 15% for peach, 10.2% for cherry, and 2.7% for apricot. The following viruses were detected: PNRSV, PDV, ACLSV and ApMV. 565 samples were tested by dot-blot and tissue-printing hybridization for the presence of Peach latent mosaic viroid (PLMVd) and Hop stunt viroid (HSVd). 48 samples were infected, 41 by PLMVd and 7 by HSVd. In addition, nested-PCR tests identified Plum bark necrosis and stem-pitting associated virus (PBNSPaV) in a few almond trees affected by stem pitting. 相似文献
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Tospoviruses infecting vegetable crops in Israel 总被引：1，自引：0，他引：1
Symptoms of vein clearing, stem necrosis, curling, necrotic spots and rings on the leaves associated with infection by tomato spotted wilt tospovirus (TSWV) were documented among vegetable crops growing in commercial glasshouses and open fields in Israel. Plants exhibiting symptoms were collected, from 1994-01 to 1998-12. Among cultivated vegetable crops analysed for TSWV by ELISA, the following plants were found to be infected: tomato, capsicum, aubergine, lettuce, cabbage and cucumber. These incidences of the virus were all correlated with the occurrence in high population of Frankliniella occidentalis. Transmission of the virus from infected Datura stramonium to Petunia leaf discs, by F. occidentalis , was up to 26%. TSWV antigens were readily detected by ELISA in seeds harvested from naturally infected vegetable crops. However, we failed to show virus transmission to the progeny plants. Iris yellow spot tospovirus (IYSV) was detected in onion. High incidence of the disease was associated with large populations of Thrips tabaci. 相似文献
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A simple procedure to evaluate relative resistance and tolerance of tomato cultivars to the begomoviruses causing tomato yellow leaf curl (TYLC) disease in Spain was developed. To estimate the resistance and tolerance levels of a cultivar, several formulae were developed based on the ratio of infected plants, virus titre (estimated by tissue–print hybridization) and symptom intensity. The formulae were applied to five commercial tomato cultivars (Amoretto, Birloque, Royesta, Tovigreen and Ulises) naturally infected by TYLC viruses. The analyses showed that Ulises, Birloque and Tovigreen exhibited a moderate resistance, and Ulises was also highly tolerant. There was a positive correlation between symptom intensity and virus titre in infected plants, suggesting that the hybridization technique could also be used as an early estimator of tolerance. Finally, molecular hybridization and nucleotide sequence analyses of the begomovirus intergenic region showed that the local TYLC virus population consisted of a single species, Tomato yellow leaf curl virus (TYLCV, formerly TYLCV-Israel), with low genetic variation (nucleotide identity between isolates higher than 97%). 相似文献
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Faba bean necrotic yellows virus (FBNYV) was isolated from naturally infected faba bean plants in Jordan. The identification was based on host range, mode of transmission, symptomatology and serological properties. FBNYV occurred naturally in several leguminous crops including cultivated legumes and wild forage legumes, such as species of Medicago , Trifolium and Lathyrus . and infected other plant species belonging to the Malvaceae, such as Malva parviflora and Hibiscus esculentus . Such hosts may act as important natural reservoirs for both the virus and its aphid vectors. This is the first report of infection of M. parviflora and H. esculentus with FBNYV. The virus was not recovered from samples taken from some cultivated crops, including squash, cucumber, tomato, eggplant and pepper, growing near to faba bean fields. Also, it was not detected in commercial faba bean seeds collected from local companies or in seeds collected from infected faba bean plants. It was transmitted efficiently by Aphis craccivora . Serological testing of 1392 samples from faba beans showing virus-like symptoms and collected randomly from 16 locations (fields) in the Jordan Valley and Jarash areas showed that FBNYV occurred in 54.5% of the samples. These results indicate that FBNYV was an important pathogen of beans during the growing season of 1996 in Jordan. 相似文献
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新疆番茄病毒病检测及南方番茄病毒全基因组序列测定与传播特性分析 总被引：2，自引：0，他引：2
为了解新疆番茄上病毒病的发生情况,利用一步法RT-PCR技术检测了南北疆番茄上南方番茄病毒(Southern tomato virus,STV)、黄瓜花叶病毒(Cucumber mosaic virus,CMV)、番茄花叶病毒(Tomato mosaic virus,ToMV)以及马铃薯Y病毒(Potato virus Y,PVY)的感染情况,并利用分段克隆的方法进行全基因组测序,通过RT-PCR方法检测健康植株与携带病毒植株杂交育种的F1代植株带毒率以分析STV的种子传播特性。结果显示,新疆番茄上CMV、STV、ToMV和PVY在北疆的检出率分别为52%、37%、27%和14%;在南疆的检出率分别为79%、60%、69%和0;且以STV、CMV及ToMV的复合侵染为主。从我国加工番茄上首次获得了长3 437 nt的STV SHZ-1核苷酸序列,序列比对分析发现其与已报道STV只有1~9个核苷酸的变异,且序列变异与地域无相关性。分析杂交F1代加工番茄植株上STV的传播特性,发现其除可由种子传播外,也可通过花粉传播。表明STV是侵染新疆番茄的主要病毒之一,且该病毒可通过种子或杂交育种途径进行传播。 相似文献
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ABSTRACT Satellite RNAs (satRNAs) are associated with Cucumber mosaic virus (CMV) in tomato, most often causing severe epidemics of necrotic plants, and not associated with specific host symptoms. Laboratory studies on virus transmission by the aphid vector Aphis gossypii were performed to better understand the dynamics of field populations of CMV. The presence of satRNAs correlated with lower concentrations of virus in infected plants and with a decrease in the efficiency of transmission from satRNA-infected plants. Both the concentration of virus in CMV-infected tomato and the efficiency of transmission varied more extensively with nonnecrogenic satRNAs than with necrogenic satRNAs. A negative effect of satRNAs on virus accumulation can account, in part, for a decrease in the field transmission and recovery of CMV + satRNAs. Aphids behaved differently and probed less readily on plants infected with CMV + necrogenic satRNAs compared with plants containing non-necrogenic satRNAs. Aphid-mediated satRNA-free CMV infections were observed in test plants when aphids were fed on source plants containing CMV + nonnecrogenic satRNA; no comparable satRNA-free test plants occurred when aphids were fed on source plants containing necrogenic satRNAs. These results indicate that factors associated with transmission can be a determinant in the evolution of natural populations of CMV and its satRNA. 相似文献
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Y. Antignus M. Lapidot N. Ganaim J. Cohen O. Lachman M. Pearlsman B. Raccah A. Gera 《Phytoparasitica》1997,25(4):319-330
Received April 24, 1997; received in final form June 29, 1997. Symptoms resembling tomato spotted wilt virus (TSWV) infections
were documented among ornamental and vegetable crops in commercial greenhouses and open fields in Israel. Plants exhibiting
these symptoms were collected from January 1992 to December 1996. Among cultivated plants analyzed for TSWV by enzyme-linked
immunosorbent assay (ELISA), 19 species representing five families were found to be infected; natural infection was also recorded
in six plant species of weeds. Virus identity was characterized by host range, serology and electron microscopy. Serological
reaction with the isolates, found in Israel, using antisera from different sources as well as the sequence analysis of the
nucleocapsid gene, demonstrated that the Israeli isolates of TSWV are a member of tospovirus serogroup I, type I (BR-01 strain).
No virus transmission was found in seeds collected from virus-infected vegetable and ornamental crops. A non-radioactive molecular
probe derived from the cloned nucleocapsid isolate enables specific detection of the virus in crude sap from infected plants.
The detection of TSWV in Israel constitutes a severe potential threat to the ornamental and vegetable industry. 相似文献
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Occurrence of melon necrotic spot carmovirus in Italy 总被引：2，自引：0，他引：2
Since 1995, a severe necrosis disease has been observed in winter melon ( Cucumis melo var. inodorus ) grown in the open in Sardegna region. At the stage of fruit ripening, infected plants show decline and premature death, a syndrome known as'collapse'. Fungal pathogens have never been detected. In 1998, melon necrotic spot carmovirus (MNSV) was isolated from diseased plants showing necrotic symptoms on leaves and branches. The virus was identified by biological and serological assays. MNSV may represent a limiting factor to winter melon production in Sardegna where the'inodorus'group is widely cultivated and appreciated for local consumption. This is the first occurrence of MNSV in Italy. 相似文献
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Luis Galipienso M Carmen Vives Luis Navarro Pedro Moreno José Guerri 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(2):175-181
Citrus leaf blotch virus (CLBV) was detected by dot-blot hybridization (DBH), and tissue print hybridization (TPH) and by one-step RT–PCR in citrus plants growing both in the greenhouse and in the field. DBH with digoxigenin-labeled cDNA probes allowed CLBV detection in dsRNA-rich and total RNA preparations equivalent to 5 and 0.1mg of infected tissue, respectively. DBH gave intense signals with RNA extracts from young bark, tender shoots and young leaves, whereas the best hybridization signals with TPH were obtained using tender shoots and young leaf petioles. One-step RT–PCR was 10-fold more sensitive than DBH and amplification was obtained with all infected tissues. CLBV was readily detected in young leaves of infected Eureka lemon, Marsh grapefruit, Nules clementine, Navelina orange and Nagami kumquat in the greenhouse, using either hybridization or RT–PCR, but not in leaves of Pineapple sweet orange. Detection in field trees was less consistent and was only achieved by RT–PCR and DBH. CLBV was detected by DBH and RT–PCR in different citrus varieties from several geographic areas showing bud union crease on trifoliate rootstocks, but not in neighbor trees with the same symptoms or in other varieties showing bud union crease on those rootstocks. Failure to detect CLBV in trees with bud union crease could be due to low virus titer or uneven distribution within the plant. Alternatively, a different agent could be involved in causing bud union crease. 相似文献
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A leaf curl and mottle disease was observed naturally affecting plants of Trigonella corniculata. A geminivirus was detected in infected plants by PCR using degenerate geminivirus primers and by Southern hybridization with a probe specific to tomato leaf curl begomovirus. This is the first report of a member of the Geminiviridae naturally occurring in T. corniculata. 相似文献
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Isabel M. Fortes Jesús Navas-Castillo 《European journal of plant pathology / European Foundation for Plant Pathology》2012,134(1):81-86
Tomato chlorosis virus (ToCV, genus Crinivirus, family Closteroviridae) causes yellowing of tomatoes in many countries worldwide. Symptoms of ToCV infections in tomatoes include inter-veinal yellow chlorotic areas that develop first on lower leaves and then advance towards the upper part of the plant. ToCV is transmitted in nature by the whiteflies Bemisia tabaci, Trialeurodes vaporariorum, and Trialeurodes abutilonea in a semi-persistent manner. In the summer of 2006, a few potato (Solanum tuberosum) volunteer plants heavily infested with the whitefly B. tabaci were found growing within a pepper crop in the province of Málaga, southern Spain. Leaf samples from volunteer plants were tested for the presence of ToCV by molecular hybridization and RT-PCR, and were shown to be infected. Furthermore, potato plants were readily infected by ToCV after experimental transmission using B. tabaci biotype Q as vector. ToCV was also detected in the tubers from infected plants that subsequently produced infected plants. Potato also served as virus source for tomato infection via B. tabaci transmission. 相似文献
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Indian peanut clump virus (IPCV) infection on wheat and barley: symptoms, yield loss and transmission through seed 总被引：1，自引：0，他引：1
Wheat and barley crops were shown to be susceptible to Indian peanut clump virus (IPCV) under field conditions. In wheat, the Hyderabad isolate of IPCV (IPCV-H) induced symptoms resembling the rosette caused by soil-borne wheat mosaic virus, and these were apparent only three weeks after emergence. Early-infected plants were severely stunted and dark green, with chlorotic streaks on the youngest leaves, which turned necrotic as the plants aged; most of these plants died. Late-infected plants were also stunted and were conspicuous in the field because of their dark green appearance as a result of delayed maturity. The virus was detected by ELISA and nucleic acid hybridization in all plants with symptoms. These plants usually produced fewer tillers than healthy ones. Spikes were malformed, often did not emerge from the flag leaf, and they contained few, shrivelled seeds. Grain yield was decreased, on average, by 58%. In barley, IPCV-H caused severe stunting and general leaf chlorosis. As the plants aged, the leaves became necrotic and the few infected plants that reached maturity produced small spikes. IPCV-H antigens were detected by ELISA in every wheat seed from infected plants and the virus was transmitted through wheat seed at a frequency of 0.5–1.3%. Storage at 4°C for more than a year did not affect seed transmission frequency. The virus was detected in leaves and roots of seed-transmitted plants. Seed transmission was not detected in barley. The Durgapura isolate (IPCV-D) was detected in wheat crops (cv. RR-21) at 3 different locations in Rajasthan State, India. Infected plants showed reduced growth without any overt symptoms. 相似文献
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Luis Galipienso María del Carmen Herranz Carmelo López Vicente Pallás José Aramburu 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(2):125-135
The genomic regions encoding the putative movement protein (MP), coat protein (CP) and intergenic region (IGR) of seven Spanish
isolates of the Parietaria mottle virus which infects tomato plants (PMoV-T) were sequenced. Values for the genetic diversity of the PMoV-T isolates were 0.056,
0.047 and 0.013 for the CP, MP genes and IGR, respectively. Nucleotide and amino acid sequence comparison of the seven PMoV-T
isolates with those of PMoV revealed significant differences. All of them had a cytosine deletion at position 1366, also confirmed
in an Italian tomato isolate, which involves a start codon for the CP gene different from that for the PMoV sequence, resulting
in a CP 16 amino acids shorter than the PMoV CP. The certainty of a cytosine deletion only associated to the tomato isolates
or the possibility of a mistake in the PMoV published sequence are the two hypotheses that could explain this difference.
Structural motifs highly conserved in Ilarviruses were identified in PMoV-T MP and CP. A stable hairpin structure is proposed
for IGR, by the initiation site for subgenomic RNA 4 synthesis. Phylogenetic analysis of CP and MP amino acid sequences showed
that Spanish PMoV-T isolates form a separate group from PMoV and other members of the Ilarvirus genus. Comparative analysis with different PMoV isolates including tomato isolates from other regions and isolates from different
hosts are necessary to confirm this differentiation. 相似文献