丁香酚对烟草抗烟草花叶病毒的诱导作用初探

为探讨植物源化合物丁香酚对烟草抗烟草花叶病毒(TMV)的诱导作用,初步研究了丁香酚对接种TMV的烟草叶片中叶绿素和丙二醛(MDA)含量,防御酶苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)和超氧化物岐化酶(SOD)活性,以及病程相关蛋白基因 PR-1 、PR-3 、PR-5 表达的影响。结果表明:丁香酚处理可促进叶绿素的合成,减轻烟草体内MDA的积累,提高PAL、POD和SOD的活性,增强 PR-1 、PR-3 、PR-5 基因的表达。表明丁香酚可提高植物的诱导抗病性,进而减轻TMV对烟草的危害。     

Semipersistency of <Emphasis Type="Italic">Myzus persicae</Emphasis> Transmission of Cucumoviruses Systemically Infecting Leguminous Plants

Sequential transmission tests of Peanut stunt virus (PSV) and Cucumber mosaic virus (CMV) systemically infecting common bean, Phaseolus vulgaris, were conducted using Myzus persicae allowed to fast for 2 hr and then to acquisition feed on infected common bean plants or purified virus for 10 min. In the sequential transmission tests using either one or 10 aphids per assay plant, three isolates of PSV (J,S,Y5) and one of CMV (V) were transmitted from and to common bean up to a third or fourth inoculation access. Many aphids transmitted these viruses to two or three plants. Purified viruses of PSV-S and CMV-V were also transmitted up to a third or second inoculation access at low percentage. On tobacco, Nicotiana tabacum, aphids transmitted PSV-S and CMV-V only in the first inoculation access, although PSV-S was transmitted to only one plant in the fourth and fifth inoculation access. These viruses may be transmitted in two phases by aphids, depending on the plant species. Received 16 April 1999/ Accepted in revised form 1 September 1999     

Biological and molecular characterization of Tomato spotted wilt Virus in Israel

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.     

Potato, an experimental and natural host of the crinivirus Tomato chlorosis virus

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.     

Exogenous application of melatonin improves plant resistance to virus infection

In this study, melatonin (MEL)-mediated plant resistance to tobacco mosaic virus (TMV) was examined to study local infection in Nicotiana glutinosa and systemic infection in Solanum lycopersicum. Exogenous application of 100 µm MEL increased anti-virus infection activity to 37.4% in virus-infected N. glutinosa plants. The same treatment significantly reduced relative levels of virus RNA analysed by qRT-PCR and virus titres measured by dot-ELISA, and increased the relative expression levels of the PR1 and PR5 genes analysed by qRT-PCR, in virus-infected S. lycopersicum. MEL treatment induced considerable accumulations of salicylic acid (SA) and nitric oxide (NO) but did not significantly affect production of hydrogen peroxide (H₂O₂) in the virus-infected S. lycopersicum plants. Transgenic nahG N. tabacum was used to determine whether MEL-induced TMV resistance was dependent on the SA pathway. The results showed that the relative RNA level of the TMV analysed by qRT-PCR and virus titres analysed by dot-ELISA were not reduced by the MEL treatment in the nahG transgenic N. tabacum seedlings treated twice with 100 µm MEL. The increased relative expression levels of PR1 and PR5 were greatly reduced when cPTIO, an NO scavenger, was included in the MEL treatment. A working model of MEL-mediated plant resistance to TMV is proposed. MEL-mediated plant resistance to viruses provides a new avenue to control plant viral diseases.     

Transmission of Tomato Yellow Leaf Curl Virus by two invasive biotypes and a Chinese indigenous biotype of the whitefly Bemisia tabaci

The global invasion of certain Bemisia tabaci biotypes provides opportunities to compare the competency of virus transmission between invasive and indigenous biotypes. Here we report on the acquisition, retention and transmission of Tomato Yellow Leaf Curl Virus (TYLCV) by the invasive B, Q and indigenous ZHJ2 biotypes of B. tabaci from Zhejiang, China. For all whitefly biotypes, TYLCV DNA was detected within a 30-min acquisition access period (AAP) to infected leaves. The percentage of adults with viral DNA increased with the length of AAP and reached 100% after 10–12 h. Following acquisition, viruliferous B, Q and ZHJ2 adults retained TYLCV DNA for the rest of their lives. Transmission was achieved with one B/Q adult per plant at the frequency of 50–55%, which rose to 100% with 10 insects per plant. In contrast, transmission of the virus was not observed with one ZHJ2 adult per plant in the experiments, and the transmission frequency rose to only 30–45% when whitefly adults increased to 5–10 per plant. These new data will help in the determination of the pest status of the whitefly biotypes as virus vectors in the regions of invasion, and so help in the development of management strategies.     

Management of the tomato borer,Tuta absoluta in Tunisia with novel insecticides and plant extracts

Tomato, Lycopersicon esculentum Mill is a vegetable crop of major importance in Tunisia. Since its detection in 2008, the tomato borer, Tuta absoluta (Meyrick), (Lepidoptera: Gelechiidae) became a serious insect pest attacking both outdoor and greenhouse tomatoes. Its control relies primarily on insecticides; hence the diversification of active substances including natural products is urgently required. The effectiveness of novel insecticides and plant extracts for the control of T. absoluta were investigated in Tunisia on tomatoes grown in greenhouses and in the laboratory in 2011. In tomato greenhouses, the following products were evaluated: Ampligo 150ZS (chlorantraniliprole + lambda‐cyhalothrin), VoliamTargo 063 SC (chlorantraniliprole + abamectin), Tracer240 SC (spinosad), Nimbecidine (azadirachtin 0.03%), Tutafort (plant extracts), Vydate (oxamyl) and Biocatch (Verticillium lecanii). In the laboratory, the products evaluated were: Ampligo 150ZS (chlorantraniliprole + lambda‐cyhalothrin), Movento OD (spirotetramat), Evisect SP (thiocyclam), Challenger SC (chlorfenapyr), Cyproma WP (cyromazine), Vydate (oxamyl), Armorex (plant extracts), Konflic (plant extracts) and Deffort (plant extracts). Greenhouse trials show good efficacy of the following products: Tracer, Nimbecidine, Biocatch, VoliamTargo, Tutafort and Vydate. However, laboratory trials demonstrate good performance of Challenger, Ampligo, Movento, Armorex, Deffort and Konflic. The integration of these products in an integrated pest management approach is discussed.     

Occurrence and Diagnosis of Tomato chlorosis virus in Portugal

Tomato chlorosis virus (ToCV), a new whitefly-transmitted and phloem-limited Crinivirus infecting tomatoes in Europe, is reported for the first time in Portugal. Tomato plants with symptoms of interveinal chlorosis, collected during autumn 1998 and summer and autumn 1999 in Algarve, southern Portugal, were positive in RT-PCR assays using ToCV-specific primers. The amplified 439bp fragment was sequenced and showed 99% homology with the ToCV sequence in the GenBank database. A digoxigenin–DNA probe was produced and tested in dot-blot with total RNAs extracted from tomato samples. Both the RT-PCR and dot-blot hybridisation procedures enabled rapid and reliable detection of ToCV from field samples.     

进境番茄种子中番茄花叶病毒的检测与鉴定

利用双抗夹心 酶联免疫吸附试验(DAS-ELISA)和反转录 聚合酶链式反应（RT-PCR）方法对来自韩国的番茄种子进行种传病毒检测。结果表明,在该批番茄种子中检测到番茄花叶病毒（ToMV）和烟草花叶病毒（TMV）。PCR产物测序结果表明,ToMV特异引物（ToA/ToB）与TMV特异引物（TA/TB）扩增的片段均为ToMV的外壳蛋白（CP）基因及3′非编码区（3′ UTR）,该片段与其他ToMV分离物的核苷酸序列相似性为98.2%~99.9%。本研究利用重新设计合成TMV和ToMV特异引物对该批种子进行RT PCR检测,仅ToMV特异性引物（ToMf1/ToMr1）扩增到670 bp的预期片段,TMV特异引物（TMf1/TMr1）则未出现特异性扩增,表明重新设计的引物可准确区分ToMV和TMV。以上结果证实该批番茄种子仅携带ToMV。     

Ceratothripoides claratris, a New Vector of a Capsicum chlorosis virus Isolate Infecting Tomato in Thailand

ABSTRACT Ceratothripoides claratris, the predominant thrips species on tomato in Thailand, was tested for vector competence and efficiency to transmit Capsicum chlorosis virus (CaCV) (isolate AIT) to tomato. The efficiency of adult-stage transmission was influenced by the larval stage at which virus was acquired. Adult C. claratris showed 69% transmission efficiency after acquiring the virus as freshly emerged (<1 h) first-instar larvae. However, when just molted (<1 h) second-instar larvae acquired the virus, the percentage of adult transmitters significantly decreased (48%). Transmission efficiency of up to 47% was detected with second-instar larvae of C. claratris which had acquired the virus as freshly emerged first-instar larvae. Transmission efficiency did not significantly differ between adult males and females, irrespective of the larval stage at which the virus was acquired. Highest transmission efficiency for CaCV was recorded in adult C. claratris derived from second-instar larvae collected from infected tomato plants in a greenhouse. Lowest transmission efficiency was observed in adults directly collected from infected tomato plants in the greenhouse. The spread of CaCV on tomato plants in greenhouses showed a close association with thrips infestations.     

Infection of Pythium sylvaticum in vitro with tobacco mosaic virus

Samenvatting Cultures vanP. sylvaticum werdenin vitro geïnoculeerd met tabaksmozaïekvirus (TMV). Virushoudende mycelia werden verder gekweekt in virusvrije media gedurende meer dan twee maanden en regelmatig getoetst op aanwezigheid van virus. Ook nadat de mycelia gewassen waren met antiserum tegen TMV kon virus er in worden aangetoond.De virusconcentratie was laag. De groei van een virushoudendePythium-cultuur verschilde duidelijk met die van een even oude, gezonde cultuur (Fig. 1). EenPythium-cultuur, 21/2 jaar geleden geïnoculeerd met virus en verder gekweekt op een vaste voedingsbodem, bleek nog virus te bevatten. Of een virushoudend mycelium het virus op een plant kan overbrengen en zo als vector kan dienen kon nog niet worden aangetoond.     

The tomato leafminer Tuta absoluta (Meyrick) in Tunisia: current status and management strategies

The tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) was first identified in the region of Akkouda in October 2008 before it spread to all tomato‐producing areas in Tunisia. The introduction of this pest disturbed existing pest control programmes in greenhouses and open fields, forcing Tunisian growers to use more chemicals to reduce its impact on their crops. A national programme was adopted to control T. absoluta, including cultural practices, the use of pheromones, the installation of insect‐proof screens in greenhouses, and the use of organic insecticides including Bacillus thuringiensis Kurstaki (Bt) and plant extract‐based products. In addition, a few experiments in biological control, using the predatory Mirid Nesidiocoris tenuis Reuter (Heteroptera: Miridae) and the parasitoid wasp Trichogramma cacoeciae Marchal (Hymenoptera: Trichogrammatidae), were conducted in greenhouses and open‐field crops (producing tomatoes for fresh consumption as well as for processing). This paper describes the status of T. absoluta in Tunisia, including data collected from sex pheromone traps installed in six tomato‐producing areas (Takelssa, Korba, Teboulba, Bekalta, Sousse and Kairouan) between 2009 and 2011, and control strategies in greenhouses and open fields.     

油菜花叶病毒15号和菸花叶病毒间干扰作用的研究

 TMV与YMV₁₅在系统感染寄主——菸(Nicotiana tabacum)上的相互干扰作用是很微弱的。同时接种二病毒时,在感染的早期(接种后2-3天) YMV₁₅占优势,在此时间以后TMV的浓度就超过YMV₁₅。二病毒以相同的侵染力同时接种心叶菸(Nicotiana glutinosa)时,则大部分的局部斑点是由YMV₁₅形成的。上述结果表明,YMV₁₅竞争侵染点的能力较TMV为大。试验并证明完整的YMV₁₅及其蛋白都能干扰TMV侵染菜豆(Phaseoluss vulgaris),因而这种干扰似决定于病毒蛋白质部分对于侵染点附着的特异性。     

Biomolecular relationships among isolates of<Emphasis Type="Italic">Tomato Yellow Leaf Curl Tanzania Virus</Emphasis>

An investigation of the biological properties of the virus causing tomato yellow leaf curl disease in Tanzania was initiated to compare it with other known tomato yellow leaf curl viruses. Properties relating to acquisition and inoculation feeding time, persistence, mechanical inoculation, seed transmission and host range were studied. Results obtained indicate that the virus was transmitted persistently byBemisia tabaci Genn., but it was not mechanically, sap- or seed-transmissible. Minimum acquisition and inoculation feeding time was 30 min.Capsicum annuum, Datura stramonium, Nicotiana glutinosa, N. tabacum andLycopersicon esculentum were found to be hosts of the virus among the plant species tested, whereasPhaseolus vulgaris was not. It is concluded that the properties of the agent causing yellow leaf curl symptoms in tomato plants from different regions in Tanzania are similar to those ofTomato yellow leaf curl Sardinia virus species studied elsewhere. http://www.phytoparasitica.org posting Feb. 20, 2003.     

毒株、苗龄及温度对烟草苗期接种TMV试验的影响

病毒株系、苗龄、接种后培养条件是影响烟草病毒病发生发展的关键因素,为确保烟草接种TMV抗性鉴定和药效生测试验的准确性,在NV基因烟草和普通烟草上接种TMV,采用病毒生物学、qRT-PCR和Western blot技术,研究病毒的分离纯化、株系、稀释限点、传导路径、病害症状,以及N基因抗TMV的温敏性.结果显示,TMV为...     

Tomato leafminer – Tuta absoluta Meyrick (Lepidoptera,Gelechiidae) – current status in Montenegro

Tomato leafminer Tuta absoluta was detected for the first time in Montenegro using pheromone traps in the middle of July 2010, in greenhouses in one location at the Montenegrin sea coast. In the period from the end of July to the first week of August, moths were captured in pheromone traps from other locations along the sea coast and surroundings of the city of Podgorica. According to the survey carried out by the authors from July to September 2010, T. absoluta was present in greenhouses in all tomato‐producing areas, while outdoors it was found only in the coastal area. Monitoring of T. absoluta continued in 2011. Pheromone traps were set up in five locations in the main tomato‐producing areas, both in greenhouses and outdoors, between 4 and 15 May. The first captured moths were detected after 7–15 days in all inspected locations, and captures continued until the end of September. According to the number of captured moths and the damage observed, it can be concluded that the population level in 2011 was lower in comparison with 2010, when up to 100% losses were detected in tomato crops in several locations. In 2011, tomato producers were already being informed about the pest and means of control, so most of them applied cultural and chemical control measures.     

Interference between potyviruses during aphid transmission

Single aphids ( Myzus persicae ) were allowed sequential access to two leaves which were either free from infection or infected with potato virus Y° (PVY°). PVY^N. beet mosaic virus (BMV), or tobacco mosaic virus (TMV). Aphids given prior or subsequent access to PVY^N-infected leaves transmitted PVY° and BMV less frequently than aphids given prior or subsequent access to virus-free leaves; those given prior or subsequent access to BMV also transmitted PVY° less frequently. However, prior or subsequent access to PVY° did not decrease transmission of either BMV or PVY^N, and access to BMV did not decrease transmission of PVY^N. Access to the non-aphid-transmissible TMV did not affect transmission of either PVY° or PVY^N. PVY^N had the greatest electrophoretic mobility. BMV was least mobile and PVY° was intermediate, so ability to decrease transmission was not directly related to the total anionic charge on the virus particles.     

Evidence of <Emphasis Type="Italic">olive mild mosaic virus</Emphasis> transmission by <Emphasis Type="Italic">Olpidium brassicae</Emphasis>

Transmission of three strains of OMMV by an Olpidium sp. was evaluated and compared. The three strains were 1) an OMMV wild type (WT) recovered from olive trees, 2) an OMMV variant (L11) obtained after 15 serial passages of single local lesions induced in Chenopodium murale plants, and 3) a construct OMMV/OMMVL11 in which the coat protein (CP) gene replaced that of the wild type. A single-sporangial culture derived from Chinese cabbage (Brassica pekinensis) used as a bait plant grown in soil of an olive orchard, was identified as Olpidium brassicae based on the size and sequence of the generated amplicon in PCR specific tests. Each of the three virus strains was soil transmitted to cabbage roots in the absence of the fungus at similar rates of 30 to 40%. Separate plant inoculation by O. brassicae zoospores incubated with each viral strain resulted in enhanced transmission of OMMV, reaching 86% of infection whereas that of the other two strains remained practically unaffected at ca. 34%. Binding assays showed that the amount of virus bound to zoospores, estimated spectrophotometrically, was 7% in the case of OMMV, and practically nil in the case of the other two viral strains. Substitution of the coat protein (CP) gene of OMMV by that of the OMMV L11 strain, drastically reduced viral transmissibility in the presence of zoospores to the level of that observed in their absence. Our data shows that OMMV soil transmission is greatly enhanced by O. brassicae zoospores and that the viral CP plays a significant role in this process, most likely by facilitating virus binding and later entrance into the host plant roots.     

<Emphasis Type="Italic">Bemisia tabaci</Emphasis> Biotype Q is present in Costa Rica

Whiteflies are an insect group that comprises multiple species and biotypes, capable of affecting crops by phloem feeding, virus transmission and promotion of fungal colonization. The distribution of these pests is worldwide. In Costa Rica, a country located in the tropics, the most problematic whiteflies are Bemisia tabaci biotype B and Trialeurodes vaporariorum. In September 2009, two greenhouses in the Alfaro Ruiz region, northwest of the country’s capital, San Jose, were surveyed as part of a larger effort to determine the occurrence of species and races of whiteflies in this agronomically important region. In addition, the insect samples were analyzed to determine the presence of Tomato chlorosis virus (ToCV), a yield-affecting crinivirus transmitted by whiteflies. The results revealed the presence of the Q biotype of B. tabaci, and important invasive species, as well as the expected T. vaporariorum. Viral detection assays identified potentially viruliferous individuals for Tomato chlorosis virus. These results identified a new pest capable of harbouring plant viruses has been identified, as well as a viral agent (ToCV) in a region where it was not reported, and which might cause significant yield losses.     

Tomato infectious chlorosis virus — a new clostero-like virus transmitted byTrialeurodes vaporariorum

A previously undescribed virus disease of tomato, other crops and weed hosts was found in California. Affected tomato plants exhibited interveinal yellowing, necrosis and severe yield losses. Leaf dips and purified preparations contained closterovirus-like long flexuous, filamentous particles approximately 12×850–900 nm. The virus, designated as tomato infectious chlorosis virus (TICV), is transmitted in a semipersistent manner by the greenhouse whitefly,Trialeurodes vaporariorum. The host range of the virus is moderate (26 species in 8 plant families) but includes some important crops and ornamental species including tomato, (Lycopersicon esculentum), tomatillo (Physalis ixocarpa), potato (Solanum tuberosum), artichoke (Cynara scolymus), lettuce (Lactuca sativa) and petunia (Petunia hybrida). The virus has been found in a number of different locations in California and has a number of potential vehicles of movement including greenhouse grown ornamentals, tomato transplants, artichoke cuttings and potato seed. The virus has the potential to spread to other growing regions with resident populations of the greenhouse whitefly. The host range, particle size, insect transmission, and serology clearly distinguish TICV from previously described viruses.