Pepper (Capsicum annuum) Is a Dead-End Host for Tomato yellow leaf curl virus

ABSTRACT Tomato yellow leaf curl (TYLC) is one of the most devastating pathogens affecting tomato (Lycopersicon esculentum) worldwide. The disease is caused by a complex of begomovirus species, two of which, Tomato yellow leaf curl Sardinia virus (TYLCSV) and Tomato yellow leaf curl virus (TYLCV), are responsible for epidemics in Southern Spain. TYLCV also has been reported to cause severe damage to common bean (Phaseolus vulgaris) crops. Pepper (Capsicum annuum) plants collected from commercial crops were found to be infected by isolates of two TYLCV strains: TYLCV-Mld[ES01/99], an isolate of the mild strain similar to other TYLCVs isolated from tomato crops in Spain, and TYLCV-[Alm], an isolate of the more virulent TYLCV type strain, not previously reported in the Iberian Peninsula. In this work, pepper, Nicotiana benthamiana, common bean, and tomato were tested for susceptibility to TYLCV-Mld[ES01/99]and TYLCV-[Alm] by Agrobacterium tumefaciens infiltration, biolistic bombardment, or Bemisia tabaci inoculation. Results indicate that both strains are able to infect plants of these species, including pepper. This is the first time that infection of pepper plants with TYLCV clones has been shown. Implications of pepper infection for the epidemiology of TYLCV are discussed.     

Evidence of a new Tomato yellow leaf curl virus in Japan and its detection using PCR

A new isolate of Tomato yellow leaf curl virus (TYLCV) has been identified from tomato plants in Kochi Prefecture in Japan and designated TYLCV-[Tosa]. The complete nucleotide sequence of the isolate was determined and found to consist of 2781 nt. In phylogenetic analyses of entire nucleotide sequences, TYLCV-[Tosa] was delineated as a single branch and was more closely related to TYLCV-[Almeria] than TYLCV isolates Ng, Sz, or Ai reported in Japan, which had spread since 1996. Isolate TYLCV-[Tosa] is suggested to be a newly introduced, novel isolate of TYLCV that dispersed into Kochi Prefecture. In addition, a rapid method using the polymerase chain reaction to separate TYLCV isolates into four genetic groups was established. This method would be useful for reliable diagnosis based on genetic differences among isolates of TYLCV.The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession numbers AB192965 and AB192966     

Detection and molecular characterization of viruses associated with tomato yellow leaf curl disease in cucurbit crops in Jordan

In this study, Tomato yellow leaf curl Sardinia virus (TYLCSV) and the strains Israel and Mild of Tomato yellow leaf curl virus (TYLCV-IL, TYLCV-Mld) were detected for the first time in four cucurbit crops in Jordan by nested polymerase chain reaction (nPCR). These viruses cause the tomato yellow leaf curl disease (TYLCD) in tomato. Cucumber, squash, melon and watermelon plants inoculated with TYLCV-IL[JO:Cuc], TYLCV-Mld, TYLCSV-IT[IT:Sar:88] and the Jordanian isolate of TYLCV (TYLCV-JV) did not show disease symptoms. However, virus-specific fragments were detected in uppermost leaves of symptomless plants by nPCR. A whitefly transmission test showed that Bemisia tabaci could transmit TYLCV-Mld from cucumber into tomato and jimsonweed plants. However, all infected tomato plants remained symptomless. In addition, results of semi-quantitative PCR (sqPCR) analysis showed that the relative amount of TYLCV-Mld DNA acquired by B. tabaci from cucumber plants was less than that acquired from tomato plants.     

侵染广西番茄的番茄黄化曲叶病毒的分子鉴定

番茄黄化曲叶病毒病是番茄生产上的毁灭性病害,严重影响番茄产量及品质。2019年从广西百色市采集疑似番茄黄化曲叶病叶片样品,采用滚环扩增(RCA)及基因克隆等方法,获得了4个烟粉虱传双生病毒的全基因序列,4个分离物的全长序列分别为2 776、2 781、2 752、2 781 bp,均编码6个开放阅读框;核苷酸相似性比较发现,4个分离物彼此间的相似性均在90%以上,与已报道的番茄黄化曲叶病毒Tomato yellow leaf curl virus (TYLCV)各分离物间的相似性也在91%以上;系统进化分析表明,TYLCV广西分离物BS-2和BS-4与TYLCV-Hunan、BS-1和BS-3与TYLCV-YN6553等分离物处于独立的小分支,说明TYLCV广西分离物与TYLCV-Hunan、TYLCV-YN6553具有较近的亲缘关系。本研究首次报道TYLCV在广西发生。     

广东省番茄黄化曲叶病毒的分子鉴定及序列分析

番茄黄化曲叶病毒病是世界番茄生产上一种毁灭性病害,番茄黄化曲叶病毒Tomato yellow leaf curl virus(TYLCV)是引起该病害的主要病原病毒之一。本文采用滚环扩增及基因克隆方法,获得了侵染广东佛山和肇庆番茄的TYLCV 4个分离物全基因组;它们均为2 781 nt,编码6个ORF,其中病毒链上编码AV1和AV2,互补链上编码AC1、AC2、AC3和AC4。同源性比较结果表明,4个广东分离物基因组序列两两间同源性为99%以上;与已报道的TYLCV各分离物同源性在90%以上,而与来自中国不同地区的TYLCV分离物的同源率均在98%以上。系统进化分析显示,广东分离物与来自中国不同地区的TYLCV分离物亲缘关系较近,并聚类在一个分支。因此,侵染引起广东佛山和肇庆番茄黄化曲叶病的病毒应来自国内其他地区。本研究是对TYLCV广东分离物分子特征的首次报道。     

吉林番茄黄化曲叶病毒分离物的检测及其DNA-A全基因组序列分析

从吉林省松原市田间表现黄化曲叶症状的番茄上分离到病毒分离物JLSY,基因组全序列测定结果表明,基因组全长2781 bp,共编码6个ORF。序列比对表明,JLSY基因组与番茄黄化曲叶病毒（TYLCV）安徽分离物（FN650807）相似性最高,为99.5%,而与其他双生病毒的序列相似性低于89%。经系统进化分析,该病毒分离物属于TYLCV以色列株系（TYLCV-IL）。这是首次在我国吉林省检测到番茄黄化曲叶病毒。     

截形叶螨抗哒螨灵种群抗性遗传方式的研究

通过对室内选育出的截形叶螨敏感品系和抗哒螨灵品系的杂交和回交试验表明:所测得的截形叶螨正交F1SR(SS♀×RR♂)和反交F1RS(RR♀×SS♂)代的显性度DSR和DRS分别为0.40和0.60,表明抗性由不完全显性基因控制;两个D值(DRS和DSR)95%置信限有重叠,并且经t检验,两个D值不存在显著差异(P0.05),证明截形叶螨对哒螨灵的抗性遗传为常染色体控制;回交F2代(BC1RS和BC1SR)的实际死亡率和期望值经χ2检验,无显著性差异(χ2=9.72,df=9,P0.05),表明抗性遗传由单基因控制。     

北京地区番茄黄化曲叶病毒病的鉴定及防治对策

番茄黄化曲叶病毒病是一种由烟粉虱传播的病毒病,给番茄生产造成严重威胁。2009年在北京郊区调查时发现部分保护地种植的番茄植株表现典型黄化曲叶症状。通过提取典型症状样品总DNA利用粉虱传双生病毒检测简并引物PA/PB,进行PCR扩增到541bp的特异条带。通过测序和核苷酸序列比对表明该序列与番茄黄化曲叶病毒序列相似性最高为99%。分子检测结果表明北京郊区部分保护地种植的番茄已被烟粉虱传播的番茄黄化曲叶病毒侵染危害。     

Epidemiology of tomato yellow leaf curl begomovirus in the Fayium area, Egypt

Tomato yellow leaf curl begomovirus (TYLCV) severely invaded tomato plantations in Egypt (Lower and Middle Egypt) in 1989. This study aimed to discover the relationship between TYLCV and other epidemic-associated factors in the Fayium area. The rate of TYLCV infection was inspected visually for three successive years (1994/1996) in the Fayium area. During the same period, whiteflies were collected for virus detection using bait-plant and DNA hybridization techniques. DAS-ELISA was used to detect mixed virus infections in tomato plants. TYLCV infection was prevalent (60–68%) and severe (2.1–3.0) in the Fayium fields. Cucumber mosaic cucumovirus (CMV) was found in some fields (5–28%) with moderate severity (1.0–20). Potato Y potyvirus (PVY) and potato leaf roll polerovirus (PLRV) were found in few fields (5–19% and 5% respectively) at very low severity. There was a negative correlation between TYLCV occurrence and distance from the source of infection, and a positive correlation (98%) between TYLCV intensity and percentage of viruliferous whiteflies in 1994 and 1995. There was no positive correlation between TYLCV and the total population of whiteflies caught during the same period. Five percent of viruliferous whiteflies, as proved by cDNA hybridization, led to 46% TYLCV infection. The same percentage of whiteflies, as shown by bioassay, led to 68% TYLCV infection. Monitoring of viruliferous whiteflies could be used for early prediction of TYLCV infection.     

Detection of Tomato yellow leaf curl Sardinia virus in Tunisia

Surveys were undertaken for tomato yellow leaf curl viruses in the main Tunisian tomato-growing areas in fields and plastic houses. Symptoms included yellowing, leaf curling and stunting. Collected samples were submitted to molecular analysis using two approaches: (1) hybridization tests with two DNA probes corresponding to an intergenic region derived from a cloned dimer of an Egyptian full-length TYLCV and to the coat region of a Tunisian TYLCV isolate; (2) PCR amplification coupled to RFLP allowing both identification and clustering of Tunisian isolates. Only Tomato yellow leaf curl Sardinia virus was detected in Tunisia.     

Current situation of Tomato yellow leaf curl virus in Portugal

The name Tomato yellow leaf curl virus (TYLCV) has been applied to a group of virus species of the genus Begomovirus in the family Geminiviridae that cause a similar tomato disease worldwide. In 1995, TYLCV was first reported in Algarve (southern Portugal) as responsible for an epidemic outbreak of a severe tomato disease. Molecular data have shown that this Portuguese TYLCV isolate was distinct from those previously reported in Europe, as it belonged to the TYLCV-Israel species ¹ . Since then, TYLCV epidemics have occurred annually, being a limiting factor mainly for autumn/winter glasshouse tomato crops. In 1998, TYLCV was also found associated with the emergence of a novel disease of Phaseolus vulgaris in Algarve. The affected bean plants were severely stunted and gave no marketable yield. However, the disease occurs only sporadically, even in conditions of high TYLCV infection pressure. Recently, Tomato chlorosis virus (ToCV), a whitefly-transmitted bipartite closterovirus (genus Crinivirus , family Closteroviridae ), was found associated with an unusual tomato yellow leaf syndrome, in single or mixed infection with TYLCV. The impact of this new pathosystem on tomato production has yet to be determined. Surveys are in progress in mixed cropping systems infested with whiteflies. So far, TYLCV and ToCV diseases are limited to the Algarve region.     

Identification of whitefly transmitted tomato yellow leaf curl geminivirus from Iran and a survey of its distribution with molecular probes

A virus causing a disease of tomato, prevalent in the southern provinces of Iran, with symptoms of leaf-curling, stunting, reduction of leaf size, leaf corrugation, shortening of internodes and severe reduction in fruit yield, was shown to be transmissible to healthy tomato plants by grafting and by whiteflies ( Bemisia tabaci ), but not by sap inoculation. Geminivirus DNA was detected in extracts of diseased tomato plants by dot-blot hybridization assays using as probes full-length cloned DNA of Australian, Italian (Sardinian) or Jordanian strains of tomato yellow leaf curl virus (TYLCV). Geminivirus coat protein was detected in whitefly inoculated plants by dot immunobinding assay using polyclonal antibody raised against Jordanian TYLCV. A limited survey using the dot-blot hybridization assay for virus detection indicated the presence of the virus in tomato-growing provinces of southern but not northern Iran. Whitefly transmission experiments to tomato under controlled greenhouse conditions showed that some isolates of TYLCV-like geminiviruses from different parts of Iran differ in symptomatology.     

侵染甜椒的番茄黄化曲叶病毒的分子鉴定和全序列分析

<正>番茄黄化曲叶病毒(Tomato yellow leaf curl virus,TYLCV)在世界范围内可危害多种作物,造成植株矮化、叶片皱缩变形、局部黄化等症状。该病毒自1964年首次报道以来已蔓延至世界多地。在我国2006年上海首次报道该病毒[1],随后江苏、山东、安徽、北京、河北、天津等地相继报道,危害严重。TYLCV为双生病毒科(Geminiviridae)菜豆金色花叶病毒属(Begomovirus)成员,基因组为单组     

陕西省番茄黄化曲叶病毒基因间隔区缺失突变体的鉴定与不同分离物间群体进化研究

为明确番茄黄化曲叶病毒(tomato yellow leaf curl virus, TYLCV)基因组的变异情况, 分别从陕西省杨凌区?泾阳县?大荔县和阎良区采集了表现为番茄黄化曲叶病症状的抗病品种番茄样品20份以及感病品种番茄样品4份?经TYLCV特异性引物检测, 24个样品均为阳性?通过全长扩增测序获得了15个TYLCV分离物的基因组序列?序列分析显示, 其中7个分离物基因组大小为正常的2 781 bp, 而有8个TYLCV分离物基因组大小为2 768 bp?与正常基因组相比, 这8个分离物在基因间隔区(intergenic region, IR)的TATA-box与保守9核苷酸序列之间发生了13个核苷酸的缺失?对我国不同地区TYLCV分离物全基因组序列进行变异分析, 发现IR区域是发生核苷酸变异最大的区域?系统进化分析表明, 本研究分离到的15个TYLCV分离物均属于TYLCV-Israel进化分支下的中国亚群, 其中8个TYLCV IR缺失突变体与国内已报道的IR缺失突变体BJ04和BJ06亲缘关系较远, 而与本研究中分离得到的正常TYLCV分离物亲缘关系最近, 疑似为陕西地区出现的一类新TYLCV IR缺失突变体?本研究首次对我国不同地区多个TYLCV分离物出现IR区缺失现象进行了报道?     

Comparison of the reaction of tomato lines to infection by tomato yellow leaf curl begomovirus in Lebanon

Tomato yellow leaf curl begomovirus (TYLCV), transmitted by the whitefly Bemisia tabaci , is epidemic in Africa, the Middle East and South-East Asia. It is also reported in some European countries and the American continent. In Lebanon, it is the major limiting factor for summer and autumn production of tomato. Comparison of the nucleotide sequence in the intergenic region with other reported leaf curl viruses showed the Lebanese TYLCV isolate to be closely related to Egyptian, Israeli and Jamaican isolates (94–96% identity). However, it is not closely related to isolates from Sardinia, Spain and Thailand, or to tomato leaf curl isolates from India, Taiwan and Australia. In field and greenhouse screening tests conducted for 5 years on 67 tomato lines, several were identified as promising. TY-Carla, PSR and RS lines were among the most promising with determinate growth, while S&G 143 and the DR lines were the most promising with semi-determinate and indeterminate growth, respectively. Virus concentrations in most, but not all, tolerant tomato lines were significantly lower than in the susceptible lines. None of the lines tested was immune to the virus. A survey of TYLCV alternative hosts on at least 58 plant species, using nucleic acid hybridization, showed that Amaranthus sp., Malva sp., Sonchus oleraceus , Plantago sp., Solanum melongena , Phaseolus vulgaris and Mercurialis annua may play an important role in the epidemiology of TYLCV in Lebanon. Mercurialis annua is a newly reported host for TYLCV.     

南疆温室番茄黄化曲叶病病毒种类的分子鉴定

为明确南疆温室番茄黄化曲叶病的病毒种类,利用双生病毒的兼并引物通过PCR扩增,对采集的20个番茄病株进行了分子检测.从20个病株中均扩增到约500 bp的目标片段,对其中4株进行克隆和测序,其相互间序列同源性为97.1％ ～99.3％,与番茄黄化曲叶病毒(Tomato yellow leaf curl virus,TYLCV)的同源性较高,为98.6％ ～ 99.5％.随机选取莎车分离物KS2-5进行全基因组的克隆和测序,KS2-5 DNA全长为2781 nt(序列号:JQ807735),具有典型的双生病毒基因组特征,与TYLCV其它分离物同源性达到98.9％～99.5％,而与其它粉虱传双生病毒的序列同源性较低,为68.3％ ～75.5％,表明危害南疆温室番茄的病毒种类为番茄黄化曲叶病毒TYLCV.     

番茄黄化曲叶病毒在湖北首次报道

2014年春季,在湖北省武汉市发现种植的番茄表现植株矮缩,叶片上卷,叶缘黄化等症状。PCR检测结果显示,所有采集的病样中均存在菜豆金色花叶病毒属病毒。进一步通过滚环扩增方法获得了该病毒的湖北分离物HB01的全基因组。基因克隆及序列分析结果表明,该病毒基因组全长为2 781nt,与已报道的番茄黄化曲叶病毒(TYLCV)各分离物同源性在89.0%以上,而与来自中国不同地区的TYLCV分离物的同源率均在97.0%以上。因此,HB01属于TYLCV的一个分离物。     

Use of Tomato yellow leaf curl virus (TYLCV) Rep Gene Sequences to Engineer TYLCV Resistance in Tomato

ABSTRACT Tomato yellow leaf curl virus (TYLCV), a member of the genus Begomovirus (family Geminiviridae), causes severe losses in tomato production in the tropics and subtropics. In order to generate engineered resistance, eight different constructs of the TYLCV replication-associated protein (Rep) and C4 gene sequences were tested in transformed tomato inbred lines. Transgenic plants were screened for resistance to TYLCV using viruliferous whiteflies. No symptoms were observed and no TYLCV genomic DNA was detected by both hybridization and polymerase chain reaction in progenies of plants transformed with three constructs. This resistance was observed in plants that contained one of the following transgenes: 2/5Rep (81 nucleotides [nt] of the intergenic region [IR] plus 426 nt of the 5' end of the TYLCV Rep gene), Delta2/5Rep (85 nt of the IR plus 595 nt of the 5' end of the TYLCV Rep gene in the antisense orientation), and RepDelta2/5Rep (81 nt of the IR, the entire Rep gene, and 41 nt 3' to the end of the Rep gene fused to Delta2/5Rep). Our study differs from other transgenic Geminivirus resistance reports involving the Rep gene in that viruliferous whiteflies were used for challenge inoculation instead of agroinoculation or biolistic inoculation, and TYLCV resistance was evaluated under field conditions.     

Panel of real‐time PCRs for the multiplexed detection of two tomato‐infecting begomoviruses and their cognate whitefly vector species

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.     

湖南省番茄和牵牛花上双生病毒的分子鉴定

双生病毒是一类在全世界范围内广泛发生的单链环状DNA病毒。本文对从湖南采集到的6例(洋姜、番茄、萝卜、赛葵、甘薯、牵牛花)疑似双生病毒侵染的植物叶片进行了分子鉴定。利用滚环扩增技术(RCA)对样品DNA进行扩增,分别对其RCA产物进行酶切,并将酶切得到的片段测序后进行BLAST比对,结果显示番茄样品中的病毒分离物与番茄黄化曲叶病毒相似性最高(99%),牵牛花样品中的病毒分离物与甘薯卷叶病毒相似性最高(99%),证明这两个分离物是单组分DNA-A双生病毒。这是在湖南省首次发现并报道双生病毒的全核酸序列。