Association between genetic variability and titre of Grapevine Pinot gris virus with disease symptoms

The present work was carried out in order to verify the possible association between a new grapevine disease, characterized by leaf mottling and deformation, and the genetic variability and concentration of Grapevine Pinot gris virus (GPGV), a recently identified virus tentatively associated with the pathology. After vineyard surveys and the establishment of real‐time qPCR assays, characterization of GPGV isolates and evaluation of GPGV titre were assessed in more than 100 samples of grapevine Glera, collected from plants regardless of whether or not they showed the symptomatology. Results showed that there was an important association between the GPGV variants and manifestation of the symptoms, and that grapevines with symptoms harboured significantly higher GPGV titre than symptomless vines. Moreover, an interesting relationship among the phylogenetic clustering of the isolates originating from plants with symptoms and some epidemiological characteristics of the disease was found. The current study confirmed the role of GPGV in the emergent disease characterized by grapevine leaf mottling and deformation.     

‘阳光玫瑰’葡萄病毒小RNA测序鉴定及RT-PCR检测

 ‘阳光玫瑰’是我国从日本引进的葡萄优良品种。为了明确我国‘阳光玫瑰’葡萄病毒病的病原,本研究采用小RNA测序技术对2株显症和无症状的‘阳光玫瑰’葡萄样品进行病毒鉴定结果显示:显症样品中测定到8种病毒,其中包含葡萄蚕豆萎蔫病毒(Grapevine fabavirus, GFabV)和灰比诺葡萄病毒(Grapevine Pinot gris virus, GPGV);无症状样品中测定到3种葡萄病毒。对46个‘阳光玫瑰’样品进行14种葡萄病毒的RT-PCR检测,结果表明:‘阳光玫瑰’葡萄带毒率较高,病毒复合侵染情况普遍;显症样品中,GFabV检出率为88.2%,GPGV和葡萄浆果内坏死病毒(Grapevine berry inner necrosis virus,GINV)检出率为64.7%和29.4%,均明显高于无症状样品(13.8%和10.3%)。本研究旨在探明‘阳光玫瑰’葡萄携带病毒的种类和侵染状况,为其病毒病防控及病毒脱除奠定基础。     

Identification of herbaceous hosts of the <Emphasis Type="Italic">Grapevine Pinot gris virus</Emphasis> (GPGV)

Grapevine Pinot gris Virus (GPGV) is a single stranded RNA of the genus Trichovirus infecting grapevine (Vitis vinifera) and associated with stunting, chlorotic mottling and leaf deformation symptoms. During a monitoring of GPGV infection in vineyards of the Trentino region in Italy, we have detected the virus in the herbaceous plants Silene latifolia subsp. Alba (Mill.) (bladder campion) and Chenopodium album L. (white goosefoot), which showed symptoms of viral infection. The full-length GPGV RNA genome, amplified from these infected hosts, was sequenced and a phylogenetic analysis revealed that its closest relative is the strain SK13, recently isolated in Slovakia. Our results indicate that herbaceous plants can be considered as a reservoir for the GPGV virus. This finding is important for studying the epidemiological aspects of GPGV disease and to formulate appropriate control measures.     

Incidence,distribution and limited genetic variability among Turkish isolates of Grapevine Pinot gris virus from different grapevine cultivars

Journal of Plant Diseases and Protection - Grapevine Pinot gris virus (GPGV) was firstly identified in northern Italy by deep sequencing from grapevine cv. Pinot gris, exhibiting mottling and...     

‘阳光玫瑰’葡萄病毒小RNA测序鉴定及RT-PCR检测

 ‘阳光玫瑰’是我国从日本引进的葡萄优良品种。为了明确我国‘阳光玫瑰’葡萄病毒病的病原,本研究采用小RNA测序技术对2株显症和无症状的‘阳光玫瑰’葡萄样品进行病毒鉴定结果显示:显症样品中测定到8种病毒,其中包含葡萄蚕豆萎蔫病毒(Grapevine fabavirus, GFabV)和灰比诺葡萄病毒(Grapevine Pinot gris virus, GPGV);无症状样品中测定到3种葡萄病毒。对46个‘阳光玫瑰’样品进行14种葡萄病毒的RT-PCR检测,结果表明:‘阳光玫瑰’葡萄带毒率较高,病毒复合侵染情况普遍;显症样品中,GFabV检出率为88.2%,GPGV和葡萄浆果内坏死病毒(Grapevine berry inner necrosis virus,GINV)检出率为64.7%和29.4%,均明显高于无症状样品(13.8%和10.3%)。本研究旨在探明‘阳光玫瑰’葡萄携带病毒的种类和侵染状况,为其病毒病防控及病毒脱除奠定基础。     

Occurrence of Grapevine Pinot gris virus in Poland and description of asymptomatic exhibitions in grapevines

Journal of Plant Diseases and Protection - Sixty five grapevines in productive areas from southern regions in Poland were tested for the presence of Grapevine Pinot gris virus (GPGV) by RT-PCR....     

Evidence of differential spreading events of grapevine pinot Gris virus in Italy using datamining as a tool

European Journal of Plant Pathology - Since its identification in 2003, grapevine Pinot gris virus (GPGV, Trichovirus) has now been detected in most grape-growing countries. So far, little is known...     

我国灰比诺葡萄病毒分离物检测及基因序列分析

 灰比诺葡萄病毒(Grapevine Pinot gris virus, GPGV)是国内新近报道的葡萄病毒,能引起葡萄叶片褪绿斑驳、皱缩及变形等症状,严重影响葡萄长势。为明确我国GPGV的发生及基因序列变异情况,本研究采用RT-PCR方法对采自我国15个省(市)自治区的195个葡萄样品进行检测,其中55个葡萄样品检测出GPGV。对49个GPGV阳性分离物的外壳蛋白(coat protein, cp)和运动蛋白(movement protein, mp)基因进行克隆、测序, 序列分析结果显示:来源于国内外的GPGV分离物cp基因和mp基因的核苷酸和氨基酸序列同源性分别为85.30%~100%和95.00%~100%、85.73%~99.87%和95.58%~100%。基于cp和mp基因序列构建的进化树,将GPGV分离物划分为3个明显的组群。其中,大部分GPGV分离物被划分在组群1内,其它中国GPGV分离物形成2个新的组群2和3。本研究是关于中国GPGV分离物基因序列变异的初次报道,可为进一步开展GPGV分子检测的技术研发及不同变种的致病性研究提供依据。     

Genetic analysis of Grapevine leafroll‐associated virus 3 population from Galicia,Spain

Grapevine leafroll‐associated virus 3 (GLRaV‐3; Ampelovirus, Closteroviridae) isolates from Galicia in northwestern Spain were selected to characterize their genetic diversity according to different factors (age, origin, location, variety, etc.). The vines belonged either to local white and red varieties autochthonous to Galicia or to varieties from other Spanish regions but widely used in Galicia. These GLRaV‐3 isolates came from different vineyards in Galicia located in coastal or inner areas. Multiplex RT‐PCR allowed the detection of isolates belonging to groups I, II, III–V and VI. Two genomic regions were studied in the isolates, the HSP70h and the capsid protein, using specific primers that allow the detection of variants from groups I to V. Some possible recombinants could be detected; however, multiple infections with different variants indicated that they were not genuine recombinants. No differences were found in the population structure considering variety or geographical factors. Isolates belonging to four groups were found in the distinct areas surveyed: groups I and II were the most common, followed by groups VI and III, as is the case in the rest of the world. In the same surveys, the presence of insect vectors for GLRaV‐3 was investigated and found lacking in inland areas but present in those with milder climate. Genetic analysis did not support isolation of the GLRaV‐3 isolates in Galicia, suggesting that the uncontrolled exchange of infected vines and/or rootstocks has been a major agent of virus spread.     

Soil application of neonicotinoid insecticides for control of insect pests in wine grape vineyards

BACKGROUND: Soil application of systemic neonicotinoid insecticides can provide opportunities for long‐term control of insect pests in vineyards, with minimal risk of pesticide drift or worker exposure. This study compared the effectiveness of neonicotinoid insecticides applied via irrigation injection on key early‐season and mid‐season insect pests of vineyards in the eastern United States. RESULTS: On vines trained to grow on drip irrigation, early‐season application of imidacloprid, clothianidin, thiamethoxam and dinotefuran provided high levels of control against the potato leafhopper, Empoasca fabae. Protection of vines against Japanese beetle, Popillia japonica, and grape berry moth, Paralobesia viteana, was also observed after mid‐season applications. Efficacy was poor in commercial vineyards when treatments were applied to the soil before irrigation or rain, indicating that vines must be grown with an irrigation system for efficient uptake of the insecticide. CONCLUSIONS: In drip‐irrigated vineyards, soil‐applied neonicotinoids can be used to provide long residual control of either early‐season or mid‐ to late‐season foliage pests of vineyards. This approach can reduce the dependence on foliar‐applied insecticides, with associated benefits for non‐target exposure to workers and natural enemies. Copyright © 2012 Society of Chemical Industry     

A yellows disease system with differing principal host plants for the obligatory pathogen and its vector

A stolbur‐type phytoplasma is the putative pathogen of grapevine yellows disease that causes economic damage to vineyards in most growing areas around the world. The pathogen is known to be transmitted to vines by two planthoppers, Hyalesthes obsoletus and Reptalus panzer; the latter is found in Europe but has not yet been observed in Israel. The establishment of a vector–pathogen–plant relationship requires that the pathogen and the vector meet on a shared host plant. This does not happen in the ecosystem examined here, where two different principal host plants for the obligate pathogen and its vector exist: the pathogen is established on vines, while its vector, H. obsoletus, develops on Vitex agnus‐castus. The present study verified that: (i) the vector cannot complete its life cycle on vines; (ii) V. agnus‐castus does not grow in the immediate vicinity of vines, and does not harbour the pathogen; and (iii) the pathogen is not vertically transmitted from mother to offspring. Moreover, in a thorough search of plants in vine growing areas, no other plants were found that host both the vector and the pathogen. However, it was found that the planthopper can acquire the phytoplasma from infected vines. Nonetheless, this does not prove the ability of the planthopper to further transmit the pathogen to vines and does not explain the presence of the vector on the non‐preferred vines. Thus, the enigma of the pathogen–vector–host triangle in this system remains unresolved.     

Survey of indigenous parasitoids affecting the invasive chestnut gall wasp Dryocosmus kuriphilus in the Friuli Venezia Giulia region (North‐East Italy)

The Asian chestnut gall wasp, Dryocosmus kuriphilus Yasumatsu (Hymenoptera, Cynipidae), is one of the most damaging insect pests on Castanea sativa Miller trees (Fagales, Fagaceae) worldwide. Dryocosmus kuriphilus galls were collected between late May and August 2014 from 11 sites in the Friuli Venezia Giulia region of North‐East Italy, differing in elevation and forest cover composition. The number of parasitoids that emerged was higher than the number of D. kuriphilus specimens that emerged for 5 out of 11 sites considered. The mean number of larval chambers per gall dissected was between 1.5 and 2.8 (for the 11 different sites). There were no fewer than 2–3 specimens of parasitoids emerging per 100 galls, in all sites. The parasitoids identified belonged to five different Chalcidoidea families (Torymidae, Eupelmidae, Eurytomidae, Pteromalidae and Eulophidae). Among them, Torymidae and Eupelmidae represented approximately 90% of the total hymenopteran parasitoids. The most represented species were Torymus flavipes (Walker), Megastigmus dorsalis (Fabricius) and Eupelmus urozonus Dalman, all indigenous parasitoids of species causing oak galls. All identified parasitoids were already known to be associated with D. kuriphilus in Italy. These data support the hypothesis of a high species richness of this parasitoid community.     

Status of insecticide resistance in Culex pipiens field populations from north-eastern areas of Italy before the withdrawal of OP compounds

BACKGROUND: Heavy and constant use of organophosphorus (OP) larvicides selected Culex pipiens L. resistant populations through two main mechanisms of genetic resistance, the increased activity of detoxifying esterase and the production of alterate acetylcholinesterase‐1 (AChE1) by G119S mutation. The aim of this study was the assessment of the distribution of Cx. pipiens populations resistant to temephos and chlorpyrifos in the north‐eastern regions of Italy and the occurrence of the insensitive AChE in these populations. Data describe the situation in the last years before European legislation prohibited the use of OP larvicides in mosquito control, up until 2007. RESULTS: For the first time a high level of OP resistance in the samples from Ravenna (182‐fold, 80% A4/B4 or A5/B5 esterases and 38.3% Ester⁵), Emilia Romagna region, was detected; therefore, new data from the Veneto and Friuli Venezia Giulia regions were obtained and reinforced existing knowledge about resistance previously studied along the Adriatic coast. Nearby, in the Villa Verucchio locality, the highest (87.5%) AChE1R was found. CONCLUSION: Cx. pipiens resistance esterases A5/B5 and A4/B4 spread southward along the Adriatic coastal plain while OPs were being used in mosquito control, as confirmed by the first molecular screening of the AChE1 gene in these populations. Copyright © 2010 Society of Chemical Industry     

Viruses and virus diseases of grapevine in Palestine

Surveys were carried out in vineyards in the main grapevine-growing areas of Palestine (Hebron, Bethlehem, Gaza, Jerusalem, Ramallah, Jenin, Jericho and Nablus) to assess the presence and incidence of virus and virus-like diseases. Leafroll symptoms were observed in Bethlehem, Ramallah and Jerusalem in native and imported cultivars, with higher rates in the red-fruited Shami, Beitoni and Smari. Rugose-wood symptoms were also observed in local and foreign cultivars, especially on grafted vines with a high incidence in Bethlehem. Fanleaf symptoms were rarely observed, while phytoplasma-induced symptoms were observed in Jenin, Jericho and Bethlehem on cvs Biadi, Superior Seedless and Beitoni. ELISA tests showed that 463 out of 566 (82%) tested vines were infected by at least one virus. GVA was the prevailing virus (66.1%), followed by GLRaV-1 (45.6%), GLRaV-3 (21.7%), GFkV (15.7%) and GLRaV-2 (8.3%). GVB and GFLV were also detected to a lesser extent, their incidence ranging between 3.7 and 1.2%, whereas GLRaV-7 was detected in a single vine of cv. Sultanina of foreign origin. Vineyards in the Bethlehem area were particularly badly damaged (97.5%), and some local cultivars were totally (Jandali, Marrawi and Shoyoukhi) or heavily infected (Zaini, Biadi and Shami). ELISA testing of 69 young rootstock mother plants showed a relatively high incidence of virus infection (20.3%). Vein necrosis and vein mosaic diseases were also ascertained on graft-inoculated 110R and Vitis riparia indicator plants, whereas no viruses other than GFLV were mechanically transmitted from about 200 vines onto inoculated herbaceous hosts.     

Viruses and virus diseases of grapevine in Tunisia

Mature canes were collected from vines in the main grapevine-growing areas in Tunisia (Cape Bon, Bizerte, Ben Arous), from commercial vineyards and mother-plant plots, to assess the presence of virus and virus-like diseases. Biological (mechanical transmission onto herbaceous hosts and grafting onto indicator woody plants) and serological detection (ELISA) methods were applied. ELISA showed that 96.4% of 669 vines tested were infected, most of them (88.1%) by at least two viruses. Grapevine leafroll-associated 3 closterovirus (GLRaV-3) was the most widespread virus (87.9%), followed by grapevine A vitiviras (GVA, 69.4%), grapevine fleck virus (GFkV, 51.9%), grapevine leafroll-associated 1 closterovirus (GLRaV-1, 36.8%), grapevine leafroll-associated 2 closterovirus (GLRaV-2, 19.1%), grapevine fan leaf nepovirus (GFLV, 18.2%) and grapevine B vitiviras (GVB, 14.8%). ELISA tests yielded negative results for grapevine leafroll-associated 7 closterovirus (GLRaV-7) and potato X potexvirus (PVX). The highest infections were found in Bizerte and Cape Bon regions (100 and 99.2%), and in vineyards aged over 20 years (98.5%) as compared with the younger ones (81.1%). Rootstocks in mother-plant plots were practically free from all the viruses tested (1 plant infected out of 81), whereas severe infections were found in Vitis vinifera mother plants (67.4% of 341 samples), in particular table grapes (92.6%) compared with wine grapes (47.9%). In these mother-plant plots, the prevailing viruses were GLRaV-3 (41.3%), followed by GFkV (36.7%), GVA (27.9%), GLRaV-1 (17%) and GLRaV-2 (15.2%). GFLV and GVB were far more limited (1.5 and 0.6%, respectively). The presence of vein necrosis and vein mosaic was ascertained by transmission onto 110R and Vitis riparia indicators, whereas only GFLV was mechanically transmitted onto herbaceous hosts (from about 20% of the samples).     

Viruses of grapevine in Albania

Grapevines were surveyed for the presence of virus and virus-like diseases in the Albanian viticultural districts of Shkoder, Lesh, Kruje, Durres, Tirana, Elbasan, Lushnje and Vlora. Symptoms of grapevine degeneration, leafroll and rugose wood were observed in all areas surveyed, whereas fleck was found in volunteer plants of Vitis rupestris at Elbasan, and enation disease in a few vines near Durres. Viruses identified were grapevine fanleaf nepovirus, grapevine fleck virus, grapevine virus A, and grapevine leafroll-associated closteroviruses I and III. ELISA tests showed that 83.5% of 530 Vitis vinifera vines and 46% of 24 American rootstocks individually checked were infected by one or more viruses. The presence of Xiphinema index , the major vector of grapevine fanleaf nepovirus, was recorded from vineyards affected by yellow mosaic.