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1.
In 2006 an outbreak of tomato yellow leaf curl disease occurred in tomato crops on Rhodes Island, Greece. Diseased plants were found to be infested with the B biotype of theBemisia tabaci (Gennadius) complex and greenhouse and open-field-grown tomato crops were infected withTomato yellow leaf curl virus (TYLCV) introduced from the Middle East. This is the first report of TYLCV and the B biotype ofB. tabaci on Rhodes Island in Greece. http://www.phytoparasitica.org posting Dec. 11, 2007.  相似文献   

2.
The recent upsurgence ofBemisia tabaci (Genn.) as an important insect pest and vector ofTomato yellow leaf curl virus (TYLCV) is directly linked to serious damage to tomato crops grown throughout Japan. The molecular genetic identification and phylogenetic relationships of 12B. tabaci populations collected from representative locations in Japan were determined based on the mitochondrial cytochrome oxidase I (mtCOI) sequence. Phylogenetic analysis of the whitefly mtCOI sequence indicated that both the invasive B and Q biotypes now occur in Japan. The Q biotype was found at four locations: Mihara in Hiroshima, Nishigoshi in Kumamoto, Miyanojo and Okuchi in Kagoshima prefectures; the remaining eight collections were identified as the B biotype. This is the first report of the introduction of Q biotype in Japan. http://www.phytoparasitica.org posting July 21, 2006.  相似文献   

3.
为了阐明丽蚜小蜂Encarsia formosa对Q型烟粉虱的寄生特性及寄主植物携带病毒对其寄生的影响,采用微虫笼饲养法研究了寄生Q型烟粉虱的丽蚜小蜂生物学特性。结果显示,丽蚜小蜂寄生Q型烟粉虱3龄若虫时,其生长发育显著优于寄生Q型烟粉虱2龄若虫。丽蚜小蜂在感染黄化曲叶病毒（TYLCV）番茄和健康番茄上寄生Q型烟粉虱（分别为VW和NVW）3龄若虫时,其生长发育特性发生了明显变化。丽蚜小蜂以VW若虫为寄主时的寿命为10.25 d,显著长于寄生NVW的丽蚜小蜂寿命（5.90 d）;对VW和NVW后代3龄若虫的寄生率分别为23.81%和17.62%,致死率分别为38.95%和26.52%,差异均显著;而丽蚜小蜂的羽化率和发育历期不存在显著差异。说明丽蚜小蜂寄生Q型烟粉虱3龄若虫时更适宜其生长发育,寄主植物番茄携带TYLCV显著提高丽蚜小蜂对烟粉虱的寄生效果。  相似文献   

4.
为有效控制日光温室番茄褪绿病毒病,于2014—2015年通过RT-PCR检测方法研究了济南市日光温室番茄褪绿病毒(Tomato chlorosis virus,ToCV)的发生规律、其与Q型烟粉虱Bemisia tabaci种群动态的关系及防虫网对该病毒病的防控效果。结果表明,春季日光温室番茄植株上Q型烟粉虱成虫数量呈增长趋势,5月下旬最高达到0.10头/叶,秋季日光温室番茄植株上Q型烟粉虱成虫数量9月上旬达最高7.42头/叶,后逐渐下降;日光温室Q型烟粉虱带毒率随着定植时间的延长而逐渐上升,之后维持相对稳定状态,即春季为20.00%~24.14%,秋季为30.00%~40.00%。日光温室ToCV发生与Q型烟粉虱成虫数量和带毒率密切相关,春季番茄最高发病率为12.00%;秋季番茄植株最高发病率为93.02%。番茄育苗和生长期用100目防虫网隔离可显著降低番茄植株带毒率。因此,秋季是日光温室ToCV防控关键期,覆盖防虫网阻隔烟粉虱可有效防治ToCV,推荐在日光温室使用。  相似文献   

5.
为明确烟粉虱Bemisia tabaci取食感染番茄黄化曲叶病毒(Tomato yellow leaf curl virus,TYLCV)的番茄植株后,其体内的芳香基硫酸酯酶B基因(arylsulfatase B,ARSB)是否能够做出应答反应,基于Q型烟粉虱基因组数据克隆得到ARSB基因cDNA全长,采用生物信息学方法分析其序列特征,并通过实时荧光定量PCR技术测定ARSB基因在Q型烟粉虱不同发育阶段、不同组织及携带TYLCV前后的表达量变化情况。结果显示:Q型烟粉虱ARSB基因的cDNA全长为1 731 bp,编码576个氨基酸,分子量为64.89 kD,具有ARSB的保守结构域。ARSB基因在Q型烟粉虱不同发育阶段均有表达,在卵期表达量最高,成虫期表达量最低;该基因在Q型烟粉虱头胸部的表达量显著高于腹部;Q型烟粉虱获取TYLCV 72 h后其体内ARSB基因表达量显著提高。表明ARSB基因在Q型烟粉虱不同龄期、不同组织内存在差异表达,并可能参与Q型烟粉虱对TYLCV的响应和传毒过程。  相似文献   

6.
BACKGROUND: Resistance to numerous insecticide classes in Bemisia tabaci Gennadius has impaired field control efficacy in south‐eastern China. The biotype and resistance status of B. tabaci collected from these areas was investigated. RESULTS: Two different biotypes of B. tabaci (B‐biotype and Q‐biotype) were detected in south‐eastern China, and the samples collected from geographical regions showed a prevalence of the Q‐biotype and the coexistence of B‐ and Q‐biotypes in some regions. Moderate to high levels of resistance to two neonicotinoids were established in both biotypes (28–1900‐fold to imidacloprid, 29–1200‐fold to thiamethoxam). Medium to high levels of resistance to alpha‐cypermethrin (22–610‐fold) were also detected in both biotypes. Four out of 12 populations had low to medium levels of resistance to fipronil (10–25‐fold). Four out of 12 populations showed low levels of resistance to spinosad (5.7–6.4‐fold). All populations tested were susceptible to abamectin. CONCLUSION: The Q‐biotype B. tabaci is supplanting the B‐biotype which used to be ubiquitous in China. Field populations of both B‐ and Q‐biotypes of B. tabaci have developed high levels of resistance to imidacloprid and thiamethoxam. Abamectin is the most effective insecticide against adult B. tabaci from all populations. Copyright © 2010 Society of Chemical Industry  相似文献   

7.
A new approach for the simultaneous identification of the viruses and vectors responsible for tomato yellow leaf curl disease (TYLCD) epidemics is presented. A panel of quantitative multiplexed real‐time PCR assays was developed for the sensitive and reliable detection of Tomato yellow leaf curl virus‐Israel (TYLCV‐IL), Tomato leaf curl virus (ToLCV), Bemisia tabaci Middle East Asia Minor 1 species (MEAM1, B biotype) and B. tabaci Mediterranean species (MED, Q biotype) from either plant or whitefly samples. For quality‐assurance purposes, two internal control assays were included in the assay panel for the co‐amplification of solanaceous plant DNA or B. tabaci DNA. All assays were shown to be specific and reproducible. The multiplexed assays were able to reliably detect as few as 10 plasmid copies of TYLCV‐IL, 100 plasmid copies of ToLCV, 500 fg B. tabaci MEAM1 and 300 fg B. tabaci MED DNA. Evaluated methods for routine testing of field‐collected whiteflies are presented, including protocols for processing B. tabaci captured on yellow sticky traps and for bulking of multiple B. tabaci individuals prior to DNA extraction. This work assembles all of the essential features of a validated and quality‐assured diagnostic method for the identification and discrimination of tomato‐infecting begomovirus and B. tabaci vector species in Australia. This flexible panel of assays will facilitate improved quarantine, biosecurity and disease‐management programmes both in Australia and worldwide.  相似文献   

8.
山东寿光地区Q型烟粉虱对番茄褪绿病毒的传播   总被引：2，自引：2，他引：0  
为明确山东寿光地区Q型烟粉虱对番茄褪绿病毒(Tomato chlorosis virus,To CV)感病流行的影响及其传毒特性,于2014年调查了该地区设施番茄上烟粉虱种群动态与To CV发病情况,利用特异引物对烟粉虱体内To CV进行了RT-PCR检测;并在室内测定了带毒Q型烟粉虱取食时间和种群数量对To CV感病株率的影响。结果表明,在番茄发病植株上采集的烟粉虱种群体内可检测到To CV;春茬番茄To CV发病株率随烟粉虱种群数量增加而逐渐升高,4—6月是To CV发生高峰期,6月22日发病株率达100%;秋茬番茄烟粉虱种群数量从10月下旬明显下降,而To CV发病株率升高,11月12日发病株率达100%;室内试验表明,To CV感病株率随着带毒Q型烟粉虱数量与取食时间的增加而明显升高。研究表明,Q型烟粉虱能有效传播To CV,且其种群数量对To CV发病株率存在显著影响,可通过防控烟粉虱以控制To CV的危害。  相似文献   

9.
BACKGROUND: B and Q biotypes of the whitefly, Bemisia tabaci (Gennadius), are generally regarded as the most significant given their global distribution and strong resistance to insecticides. Since these biotypes can coexist and differ markedly in their insecticide resistance profiles, a rapid but reliable means of discriminating between them would be a valuable complement to resistance monitoring and management programmes. Recently, PCR‐based methods have been developed to determine the biotype status of B. tabaci populations. However, these require post‐amplification procedures, which increase time and labour. RESULTS: The authors have developed an allelic discrimination real‐time PCR assay using fluorescent dye‐labelled probes to distinguish the B and Q biotypes. The assay targets a single nucleotide polymorphism (SNP) in the mitochondrial cytochrome oxidase I (mtCOI) gene. To evaluate the assay, DNA was extracted from individual whiteflies of six known biotype strains, and all scored correctly as either a B or Q biotype. As further validation, 72 individuals from field samples collected in different parts of the world were also tested by the assay. No failed reactions were observed, with all 72 samples scoring clearly as either the B or Q biotype. CONCLUSION: The development of this rapid and high‐throughput assay has important potential for routine monitoring of B and Q biotypes on ornamental plants and for the screening of B. tabaci populations in countries where these biotypes are not yet established. Copyright © 2007 Society of Chemical Industry  相似文献   

10.
为明确烟粉虱传播的番茄褪绿病毒(Tomato chlorosis virus,ToCV)与番茄黄化曲叶病毒(Tomato yellow leaf curl virus,TYLCV)对不同番茄品种的复合侵染情况,于2015年11月在山东省寿光市温室内采集13个番茄品种共390份疑似发病植株叶片,对不同番茄品种的TYLCV抗性和2种病毒的复合侵染以及温室内发病番茄植株上烟粉虱成虫的带毒率进行检测。结果表明,采集的13个番茄品种经分子标记检测鉴定均为TYLCV杂合抗性;不同番茄品种ToCV与TYLCV的复合侵染率存在明显差异,大果番茄粉宴和贝瑞上复合侵染率最高可达73.3%,而樱桃番茄八喜上未检测到这2种病毒的复合侵染。此外,在发病番茄植株上采集的烟粉虱成虫体内可检测到2种病毒,其中烟粉虱ToCV带毒率为90.7%,TYLCV带毒率为80.0%,同时检测到ToCV与TYLCV的概率为71.3%。表明ToCV和TYLCV的复合侵染在山东省番茄生产中普遍发生,烟粉虱可同时携带这2种病毒并广泛传播。  相似文献   

11.
Acetylated glyceride (Bemidetach?EC)—a food additive—repels adult sweet potato whiteflies (Bemisia tabaci) and inhibits their mating behavior. We evaluated the effects of acetylated glyceride spraying of greenhouse-grown tomato plants on infestation with B. tabaci and the occurrence of Tomato yellow leaf curl virus (TYLCV) disease under commercial-like conditions. The abundance of adult B. tabaci was significantly reduced by three sprayings of acetylated glyceride, and the TYLCV incidence was significantly suppressed to less than 30% of that in the untreated control. These results suggest that acetylated glyceride sprays suppress the secondary spread of TYLCV in greenhouse-grown tomatoes by lessening B. tabaci adult density.  相似文献   

12.
For the UK, Bemisia tabaci poses a threat primarily to protected vegetable crops due to the transmission of several plant-pathogenic viruses. There are at least 24 different biotypes of B. tabaci that cannot be differentiated through morphological traits. The B (Middle East-Asia Minor 1 species) and Q (Mediterranean species) biotypes are widely considered to be the most important and, as such, the ability to rapidly and precisely biotype B. tabaci interceptions is vital when developing effective control strategies. Intercepted adult/pupal B. tabaci received from the UK Plant Health and Seeds Inspectorate (PHSI) during 2002–2003 (n?=?60) and 2010–2011 (n?=?42) were both biotyped and tested for the presence of Tomato yellow leaf curl virus (TYLCV) and Tomato yellow leaf curl Sardinia virus (TYLCSV) using a real-time PCR assay based on TaqMan? chemistry. The positive results indicated that during 2002–2003 the Q biotype comprised 68.3?% of the interceptions whilst in 2010–2011 it comprised 66.7?% of the B. tabaci samples intercepted. Only three of the B biotypes collected during 2002–2003 were positive for TYLCSV, two originating from Israel and the other of unknown origin. The implications in regards to pest management of the insect are discussed.  相似文献   

13.
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.  相似文献   

14.
ABSTRACT The effect that Tomato yellow leaf curl virus (TYLCV)-infected resistant tomato plants may have on virus epidemiology was studied. Four tomato genotypes that exhibit different levels of viral resistance, ranging from fully susceptible to highly resistant, served as TYLCV-infected source plants. Viral acquisition and transmission rates by white-flies following feeding on the different source plants were evaluated. TYLCV transmission rate by whiteflies that had fed on infected source plants 21 days postinoculation (DPI), shortly after the appearance of TYLCV symptoms, was negatively correlated with the level of resistance displayed by the source plant. Therefore, the higher the resistance, the lower the transmission rate. In addition, TYLCV DNA accumulation was shown to be lower in the resistant source plants compared with the susceptible plants. Whitefly survival rate, following feeding on source plants 21 DPI, was similar for all the cultivars tested. Significant differences in whitefly survival were found, however, following feeding on the infected source plants at 35 DPI; here, whitefly survival rate increased with higher levels of resistance displayed by the source plant. At 35 DPI, the susceptible plants had developed severe TYLCV disease symptoms, and transmission rates from these plants were the lowest, presumably due to the poor condition of these plants. Transmission rates from source plants displaying a medium level of resistance level were highest, with rates declining following feeding on source plants displaying higher levels of TYLCV resistance. TYLCV DNA accumulation in whiteflies following feeding on infected source plants at both 21 and 35 DPI was directly correlated with viral DNA accumulation in source plants. Results show that, in essence, the higher the resistance expressed, the less suitable the plant was as a viral source. Consequently, following acquisition from a highly resistant plant, TYLCV transmission by whiteflies will be less efficient.  相似文献   

15.
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.  相似文献   

16.
Virus transmission studies were conducted under glasshouse conditions using the vector Bemisia tabaci biotype B to determine how effectively isolates of the begomoviruses Tomato yellow leaf curl virus (TYLCV) and Tomato leaf curl Bangalore virus (ToLCBV) could be transmitted to phaseolus bean, capsicum and tomato test plants, the latter host used as a positive control for transmission. Diagnostic detection of viruses in these host crops and vector was also evaluated. Polymerase chain reaction (PCR) detection of TYLCV in bean cv. Wade and capsicum cv. Bellboy was achieved 4 weeks after fumigation in asymptomatic plants. Detection of TYLCV in tomato controls was achieved 2 weeks after fumigation with improved frequency of detection at 4 weeks. PCR was found to be a more sensitive method than triple‐antibody sandwich enzyme‐linked immunosorbent assay (TAS‐ELISA) for the detection of TYLCV isolates in all hosts. ToLCBV was detected by PCR and TAS‐ELISA in bean. TYLCV was also detected by PCR in the vector, with a novel internal positive control. This work was carried out to facilitate the development of a diagnostic protocol for the begomoviruses causing tomato yellow leaf curl under the EU SMT programme project –‘Diagnostic protocols for organisms harmful to plants’ (DIAGPRO).  相似文献   

17.
为明确L-阿拉伯糖对B型和Q型烟粉虱毒性及其取食行为的影响,调查了饲喂含有L-阿拉伯糖人工饲料后烟粉虱的死亡率,利用刺吸电位技术(EPG)记录其取食行为,并观察了饲喂后其在人工饲料膜上的刺孔数量及直径。结果表明,B型和Q型烟粉虱的校正死亡率均随L-阿拉伯糖浓度及饲喂时间的增加而升高;在3种浓度下,B型烟粉虱校正死亡率均显著高于Q型烟粉虱;在5%、10%浓度下,Q型烟粉虱校正死亡率分别在第5天和第3天达100%,B型烟粉虱分别在第3天和第2天达到100%;5%L-阿拉伯糖对B型烟粉虱取食行为影响比Q型大;在5%浓度下,B型和Q型烟粉虱在膜上的刺孔数量总体少于对照组。研究表明,L-阿拉伯糖对烟粉虱具有杀虫活性,且对B型和Q型烟粉虱的毒性效果不同。  相似文献   

18.
Protected tomato is the most important horticultural crop in the Algarve (south of Portugal). However, the growing area has decreased by almost 48% since 1995, mainly as a result of the pests Bemisia tabaci and Trialeurodes vaporariorum and the epidemics of Tomato yellow leaf curl virus (TYLCV), a Begomovirus transmitted by B. tabaci. Both whiteflies are vectors of economically important viruses. Recently, Tomato chlorosis virus (ToCV), a member of the genus Crinivirus, transmitted by both B. tabaci and T. vaporariorum, was reported infecting tomato crops in Algarve. A study was carried out to evaluate the dynamics of whitefly populations on tomato crops in Algarve. Population counts of B. tabaci were high in the first months of autumn, then decreased until January, when numbers of T. vaporariorum became higher. Counts of B. tabaci then increased again.  相似文献   

19.
Bemisia tabaci (Gennadius) adults were collected from poinsettia plants (Euphorbia pulcherrima) in retail nurseries in Cd. Obregon and Navojoa, Sonora, Mexico. A single field sample was collected from broccoli plants in Obregon, Sonora. Both adult whitefly and immature instars were observed on infested leaves. Whiteflies were identified asB. tabaci using morphological characters of the pupae to distinguish them from the greenhouse whitefly; and to specific biotype, by molecular analysis using the mitochondrial cytochrome oxidase I (mtCOI) sequence. Phylogenetic analysis of mtCOI sequences indicated that poinsettias were colonized both by the Q and the B biotype. The Q biotype was found only on poinsettia plants, and one poinsettia sample was infested with both the Q and the B biotype. The B biotype alone was associated with the field-collected broccoli sample analyzed in the study. A more extensive survey is required to determine the extent of the distribution of the Q biotype in Mexico, particularly where ornamental plants are transported from central to northern Mexico. Such plants could serve as the source of the Q biotype, which has been reported to be highly resistant to insecticides including the neo-nicotinoids that are widely used to control the B biotype in much of Mexico. This is the first report of the Q biotype in Mexico. http://www.phytoparasitica.org posting May 2, 2007.  相似文献   

20.
A. Lopes 《EPPO Bulletin》2002,32(1):7-10
In Portugal during the 1960/1980s, there was intensive development of vegetable crop production, in particular protected crops, of which tomato was the most important. The main producing regions now are Ribatejo e Oeste, Alentejo and Algarve. Tomato presents extensive phytosanitary problems, being host to a wide range of pests, including the whiteflies Trialeurodes vaporariorum, in protected crops, and Bemisia tabaci, in protected and field crops. Portugal has applied for the status of an EU ‘protected zone’ for this latter pest. As B. tabaci is an important vector of a large number of viruses, including tomato yellow leaf curl viruses (TYLCV), a monitoring programme of the tomato crop was implemented in Portugal. Preliminary data are presented concerning B. tabaci in the three main tomato‐growing regions of the country.  相似文献   

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