番茄黄化曲叶病毒与番茄褪绿病毒复合侵染对番茄黄化曲叶病毒传播的影响

番茄黄化曲叶病毒(tomato yellow leaf curl virus, TYLCV)是一种由烟粉虱传播的单链环状DNA病毒, 在田间可与多种病毒发生复合侵染, 如番茄褪绿病毒(tomato chlorosis virus, ToCV)等?本文对比了TYLCV单独侵染和TYLCV与ToCV复合侵染对烟粉虱获取和传播TYLCV的影响?结果表明, 与取食TYLCV单独侵染的番茄相比, 取食复合侵染番茄的烟粉虱对TYLCV的传毒率显著提高, 且番茄植株和烟粉虱体内TYLCV的病毒积累量也显著提高?试验结果说明复合侵染会提高烟粉虱的传毒率, 促进TYLCV的发生与流行?     

陕西省早春茬番茄定植时间与番茄黄化曲叶病毒病发生的关系

为了明确早春茬番茄定植时间与番茄黄化曲叶病毒病发生的关系,采取小区对比试验对不同定植时间下番茄上烟粉虱种群消长动态、番茄黄化曲叶病毒病发病株率、发病程度及番茄产量和经济效益等进行了系统调查。结果表明:番茄田烟粉虱种群消长动态在年度间基本相同,4月上旬始见,5月中旬达到高峰,烟粉虱发生后15 d左右出现番茄黄化曲叶病毒病症状。4月上旬以前定植番茄黄化曲叶病毒病发生较轻,单位面积产量和经济效益较高,4月上旬以后定植发病较重,产量和经济效益较低。定植时间(X_1)与番茄黄化曲叶病毒发病株率(Y_1)及病情指数(Y_2)均呈显著正相关,其相关关系为Y_1=1.470 4X_1+7.947 2,Y_2=0.876 7X_1-6.441 7。生产实践中采取双膜或三膜覆盖栽培等措施适当提早定植,避免番茄感病期与烟粉虱发生高峰期相遇,在不使用任何防治措施下,可有效预防番茄黄化曲叶病毒病暴发成灾。     

Pcr-amplification of tomato yellow leaf curl virus (TYLCV) DNA from squashes of plants and whitefly vectors: Application to the study of TYLCV acquisition and transmission

DNA of tomato yellow leaf curl virus (TYLCV), a geminivirus transmitted by the whitefly Bemisia tabaci, was amplified from squashes of infected tomato plants and of viruliferous vectors using the polymerase chain reaction (PCR). Samples of infected tissues as small as 1 mm² were squashed onto a nylon membrane. A 1 × 2 mm strip containing the squash was introduced into a 25 µl PCR reaction mix. The reaction products were subjected to gel electrophoresis, blotted and hybridized with a radiolabeled virus-specific DNA probe. TYLCV DNA was amplified from squashes of leaves, roots, and stem of infected tomato and from individual viruliferous whiteflies. The same squash could be used several times to amplify different virus DNA fragments with various sets of primers. Thus plant and insect squashes can be used as templates for the amplification of geminiviral DNA with no need to prepare tissue extracts or purify nucleic acids. The squash-PCR procedure was applied to study whitefly transmission of TYLCV. Tomato plants were inoculated by placing a single viruliferous insect in the center of a young leaflet. In some plants TYLCV DNA was detected at the site of inoculation as early as 5 min after the beginning of the access feeding and in all plants after 30 min. The squash-PCR procedure also was applied to the study of TYLCV acquisition by the insect vector. TYLCV DNA was detected in the head of whiteflies as early as 5 min after the beginning of the access feeding on infected tomato plants. Viral DNA was detected in the thorax after 10 min and in the abdomen after 25 min.     

Solanum nigrum: an indigenous weed reservoir for a tomato yellow leaf curl geminivirus in southern Spain

A tomato yellow leaf curl geminivirus (TYLCV-AL), was first identified in tomato plants in Almeria, southern Spain in 1992. This virus is transmitted by the tobacco whitefly, Bemisia tabaci (Gennadius), and is presently infecting tomato crops throughout the south eastern region of Spain. Solanum nigrum, collected from a field in south east Spain and exhibiting leaf curl symptoms, was squash blotted onto nylon membrane and gave a positive signal when hybridised to a TYLCV-Is DNA probe. Laboratory tests showed B. tabaci to transmit TYLCV-AL from infected tomato plants to S. nigrum seedlings. The virus could then be acquired by B. tabaci and transmitted back from infected S. nigrum plants to tomato, inducing typical TYLCV symptoms. These results indicate the importance of S. nigrum as a weed host/reservoir for a TYLCV and its possible role in the spread of this virus within Europe.     

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.     

番茄SlAGO1的表达分析及其抗番茄黄化曲叶病毒(TYLCV)功能研究

 本研究运用 MEGA 7.0 进行多序列比对并构建系统进化树,利用实时荧光定量 PCR(qRT-PCR)分析SlAGO1在番茄组织中的表达水平及接种TYLCV后的防御响应;通过沉默番茄八氢番茄红素脱氢酶基因SlPDS,建立‘矮番茄'沉默体系,采用 qRT-PCR 分析SlAGO1在沉默后对TYLCV表达的影响。系统进化树结果显示SlAGO1a/b(SlAGO1)氨基酸序列同源性极高,暗示其为同一个基因在染色体上的多个拷贝;qRT-PCR分析表明,SlAGO1在花、叶中显著表达,且受TYLCV的诱导表达;VIGS沉默SlAGO1后接种TYLCV侵染性克隆,植株表现出明显的病毒症状,qRT-PCR分析显示病毒含量显著高于对照,表明SlAGO1在番茄植株抗病毒中发挥重要作用。研究结果可为番茄抗病毒机制研究及番茄抗病毒育种奠定基础。     

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。     

浙南菜区番茄曲叶病毒病发生规律

通过两年调查,明确了浙南菜区越冬番茄曲叶病毒病的主要侵染期在9月下旬至10月上旬,即番茄苗龄20~30 d。温州近郊常年蔬菜生产基地,番茄曲叶病毒病的侵染循环主要通过携毒烟粉虱在越冬番茄和早春番茄间传播完成。苍南、瑞安等季节性番茄生产基地,该病的侵染循环主要通过携毒烟粉虱在越冬番茄、大田番茄苗和夏季南瓜等中间寄主传播完成。随着播种期推迟,番茄曲叶病毒病发生轻,目前浙南菜区生产上‘托马雷斯’、‘好韦斯特’、‘合作903’等主栽番茄品种均表现感病。田间调查还表明,通过50目防虫网覆盖育苗栽培可以有效控制番茄曲叶病毒病发生,防控效果达到90%以上。     

不同番茄品种对番茄黄化曲叶病毒的抗病性鉴定

为评估生产上常用番茄栽培品种对番茄黄化曲叶病毒(Tomato yellow leaf curl virus,TYLCV)的抗性水平,采用田间大棚自然传毒的方式,通过对各品种的发病时间、发病率及病情指数等参数的比较,结合PCR及ELISA对TYLCV的检测结果,综合分析了20个番茄品种对番茄黄化曲叶病毒的抗病性。不同品种对番茄黄化曲叶病毒的抗性差异较大,试验筛选出仙客6号和金棚1号2份感病材料,发病率和病情指数在90%和60.9以上;佳红8号、10-秋展47和红罗曼2号3份高抗材料,发病率和病情指数均为0;其它表现不同程度抗、耐病水平的材料15份,发病率和病情指数分别在10.0%～85.0%和1.0～40.6之间。     

天津市烟粉虱隐种鉴定及其携带TYLCV、内共生菌情况和抗药性监测

为明确天津市烟粉虱Bemisia tabaci隐种的类别及其寄主适应性、传毒能力、携带内共生菌情况和抗药性,采用mt COI酶切法对从武清、西青、蓟州和宁河4个区的番茄、黄瓜及辣椒3种寄主上采集的12个烟粉虱种群进行隐种鉴定,采用PCR检测其携带番茄黄化曲叶病毒（tomato yellow leaf curl virus,TYLCV）和内共生菌情况,并采用浸叶法测定其对4种常用药剂的抗性。结果表明,采集的烟粉虱种群以MED隐种为主,占所有检测个体的93.33%,有3个种群为MED和MEAM1隐种混合发生。所有检测个体中有36.25%的个体携带TYLCV,在6个种群中检测到TYLCV,其中5个种群有超过50%的个体携带TYLCV。在12个种群中共检测到Hamiltonella、立克次氏体Rickettsia、Cardinium和杀雄菌属Arsenophnus共4种内共生菌,携带个体比例分别为90.63%、48.96%、43.75%和8.33%,进一步对内共生菌协同感染情况进行分析,发现有HARC、HRC、HAC、HR、HC和AC共6个协同感染型,感染率分别为4.17%、28.13%、3....     

番茄褪绿病毒病在山东设施西葫芦上的发生及潜在危害

番茄褪绿病毒tomato chlorosis virus (ToCV)是我国蔬菜生产的重要新发病毒,其寄主范围逐年扩大。2019年10月项目组在山东寿光西葫芦温室调查时发现部分叶片呈现黄化、脉间褪绿,类似于ToCV侵染症状,并伴有烟粉虱发生。利用特异性引物检测发现,扩增的目的片段与GenBank中登录的侵染番茄的ToCV基因序列(登录号：KC887998.1)同源性高达99.58%,充分说明西葫芦植株已被ToCV侵染。通过对病毒病发生规律和烟粉虱虫口数量调查发现,西葫芦定植后1个月表现侵染症状的植株为2.0%,定植后2个月达到4.2%,定植后4个月后高达68.2%,病毒发生呈指数增长,而烟粉虱虫口数量却维持较低密度。从济南和德州采集的西葫芦疑似病叶和烟粉虱中也检出ToCV病毒,说明该病毒可能已经在山东省设施西葫芦主要种植区普遍发生,并经烟粉虱广泛传播,需引起高度重视。     

番茄褪绿病毒与番茄黄化曲叶病毒复合侵染对番茄褪绿病毒传播的影响

番茄褪绿病毒Tomato chlorosis virus(ToCV)是一种由烟粉虱Bemisia tabaci传播的正义单链RNA病毒,在田间常与番茄黄化曲叶病毒Tomato yellow leaf curl virus(TYLCV)复合侵染而造成番茄生产上重大的经济损失。为了明确ToCV与TYLCV的复合侵染对烟粉虱传播ToCV所造成的影响,本文采用RT-PCR以及qRT-PCR检测了复合侵染的番茄对烟粉虱获取和传播ToCV的影响。研究表明,烟粉虱取食复合侵染的番茄后对ToCV的传播效率显著提高,仅25头烟粉虱的传毒率即可达到100%,ToCV在烟粉虱以及番茄体内的累积量均显著提高。说明这种复合侵染促进了烟粉虱对ToCV的传播,在田间应当及时防控烟粉虱,警惕病毒与烟粉虱的蔓延。     

木尔坦棉花曲叶病毒在新疆的发生分布及烟粉虱带毒检测

为了明确木尔坦棉花曲叶病毒cotton leaf curl Multan virus (CLCuMuV)在新疆的发生分布,对采自新疆13个地(州)的1 166份蜀葵、苘麻、棉花疑似病株进行CLCuMuV分子鉴定和带毒检测,并对3种寄主上同期采集的1 588头烟粉虱进行隐种鉴定和带毒检测。结果显示,CLCuMuV DNA-A组分及其伴随的DNAβ卫星分子均可侵染蜀葵、苘麻、棉花;基于DNA-A及DNAβ组分的进化分析表明,新疆3种寄主上发生的CLCuMuV与国内已报道的CLCuMuV进化关系一致;蜀葵、苘麻、棉花上CLCuMuV带毒率存在差异,分别为27.87%、33.33%和14.95%;MEAM1和MED隐种为新疆烟粉虱主要种群,分别占26.70%和66.44%,带毒率分别为21.46%和17.63%,说明MED隐种为新疆烟粉虱优势种群,2个隐种均可携带CLCuMuV且带毒率相近;MEAM1隐种在蜀葵、苘麻、棉花上带毒率分别为21.39%、0和28.21%,MED隐种分别为19.61%,8.47%和11.18%,表明2个隐种在不同寄主上的带毒率存在差异。本研究明确了新疆地区侵染蜀葵、...     

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.     

Farmers' perceptions and practices for managing tomato leaf curl virus disease in southern India

A survey of 174 tomato farmers in five districts of Karnataka State, South India, was conducted between March and July 1998 with the objectives of assessing farmers' knowledge and perceptions of tomato leaf curl virus disease (ToLCVD) and examining their current control practices. The findings showed that farmers were familiar with ToLCVD and regarded it as a serious constraint upon production, particularly in the hot season. However, only 2% of farmers were aware that tomato leaf curl virus (ToLCV) was transmitted by a whitefly vector, Bemisia tabaci . A similarly small number of farmers knew that ToLCVD was caused by a virus, whilst 86% of farmers believed that it was caused by high temperatures. Approximately 90% of farmers relied primarily on pesticides for control of ToLCVD. Few ToLCV-resistant varieties were available but one such variety, Avinash II, was grown by 13% of farmers in the hot season when incidence of the disease is highest. Farmers visiting experimental trials at a farmer field day, showed a strong interest in new advanced breeding tomato lines with resistance to ToLCV. Factors affecting the adoption of ToLCV-resistant varieties by tomato farmers are discussed.     

番茄地烟粉虱空间格局参数特征及其应用

2006年通过对春季番茄烟粉虱不同发生密度地块调查,取得了11组样本资料,应用聚集度指标法I、wao法和Taylor法等对其空间分布型进行测定检验,结果表明烟粉虱成虫在番茄上呈聚集分布,其聚集度是随着种群密度升高而增加。其聚集原因经Blackith种群聚集均数测定,当m<2.9638时,其聚集是由于某些环境如气候、栽培条件、植株生育状况等所引起的;当m≥2.9638时,其聚集是由害虫本身的聚集行为与环境条件综合影响所致。比较几种抽样方式以五点式为最佳,并提出了最佳理论抽样数和最佳序贯抽样模型:N=1.962/D2[1.007 9/m+0.0633],Tn=1.0079/[D20-0.0633/n]。     

侵染新疆加工番茄的中国番茄黄化曲叶病毒 DNA-A的基因组特征

 从新疆加工番茄上分离到病毒分离物XJ26-4,对其基因组DNA-A 全序列测定表明,XJ26-4 DNA-A 全长2 737 个核苷酸(GenBank 登录号:FN985163),具有典型的双生病毒基因组特征。进一步序列比较发现,XJ26-4 DNA-A 与中国番茄黄化曲叶病毒(Tomato yellow leaf curl China virus, TYLCCNV)各分离物的同源性最高,达到91. 2% ~ 99. 5% ,而与其他双生病毒的序列相似性均在79. 5% 以下,表明XJ26-4 是TYLCCNV 的一个分离物。这是首次明确新疆加工番茄受到粉虱传双生病毒的侵染。     

侵染假酸浆的泰国番茄黄化曲叶病毒全基因组结构特征

为明确假酸浆Nicandra physalodes叶片黄化、皱缩症状是否由菜豆金色花叶病毒属病毒侵染引起,本研究利用分子检测方法和生物信息学技术鉴定了假酸浆样品中的病毒种类。从采集的病样中克隆并获得了2条菜豆金色花叶病毒属病毒DNA-A全序列和1条beta卫星全序列,经全序列分析发现,该双生病毒的两条DNA-A全序列与泰国番茄黄化曲叶病毒(tomato yellow leaf curl Thailand virus, TYLCTHV)云南分离物TYLCTHV-YN1732一致性最高,达99.3%,亲缘关系较近;beta卫星的全序列与云南番茄曲叶beta卫星(tomato leaf curl Yunnan betasatellite, TLCYnB)的分离物YN5230一致性最高,达99.3%,亲缘关系较近。重组分析显示,假酸浆上分离的TYLCTHV-YN5735-12是一个重组病毒,有两个重组事件,一个主要发生在AV1的编码区,由中国番茄黄化曲叶病毒(tomato yellow leaf curl China virus, TYLCCNV)和广西大戟曲叶病毒(euphorbia lea...