葡萄的两种检疫性病毒的多重RT-PCR检测

 本研究利用多重RT-PCR技术,对葡萄的检疫性病毒中番茄环斑病毒(ToRSV)和烟草环斑病毒(TRSV)进行检测,并研究了反应体系中各个参数对多重RT-PCR的影响。结果表明:可以在同一反应体系中实现对ToRSV和TRSV的RT-PCR检测,但模板浓度、引物浓度、循环数等3个因素对检测结果的准确性有较大的影响,3个参数的增加都会导致非特异性扩增的增多,而dNTP以及Taq酶的浓度对实验结果并无较大影响。     

Detection of two viruses infecting Narcissus by enzyme-linked immunosorbent assay

The enzyme-linked immunosorbent assay (ELISA) proved sufficiently reliable to detect narcissus tip necrosis virus (NTNV) and arabis mosaic virus (AMV) in Narcissus leaf material provided it was of the right age. Similar trends in virus concentration in leaf samples were indicated by ELISA reactions for both viruses, with highest levels at the start of growth, a decrease during flowering, followed by an increase before levels fell as leaves died. Leaf tip samples consistently provided the highest ELISA reactions at all stages and testing was more reliable from outer, older leaves than inner, younger ones. Best samples for ELISA detection of both viruses were from the tips of older leaves early in the growing season.     

侵染肥城桃的病毒和类病毒的分子检测与鉴定

为明确山东肥城桃种植区桃树上主要存在的病毒和类病毒及其发生情况,采集具有花叶、斑驳和皱缩典型症状的肥城桃样品,提取叶片总RNA后,分别选用桃树上已报道的啤酒花矮化类病毒Hopstuntviroid(HSVd)、桃潜隐花叶类病毒Peach latent mosaic viroid(PLMVd)、苹果褪绿叶斑病毒Apple chlorotic leaf spot virus(ACLSV)、樱桃锉叶病毒Cherry rasp leaf virus(CRLV)、桃花叶病毒Peach mosaic virus(PMV)、李属坏死环斑病毒Prunus necrotic ringspot virus(PNRSV)、李痘病毒Plum pox virus(PPV)、李矮缩病毒Prunus dwarf virus(PDV)、樱桃绿环斑驳病毒Cherry green ring mottle virus(CGRMV)、杏假褪绿叶斑病毒Apricot pseudo-chlorotic leaf spot virus(APCLSV)、李树皮坏死茎纹孔伴随病毒Plum bark necrosis stem pitting-associated virus(PBNSPaV)和小樱桃病毒1号Little cherry virus 1(LchV1)的特异性引物进行RT-PCR检测。PCR结果显示仅HSVd、PLMVd、ACLSV、PNRSV和PBNSPaV的扩增产物中得到了预期大小的目的片段,将目的片段克隆测序后,经NCBI BLAST比对发现,山东肥城桃分离物HSVd、PLMVd、ACLSV、PNRSV和PBNSPaV与GenBank已报道分离物序列一致性均达90%以上。表明山东肥城桃已感染HSVd、PLMVd 2种类病毒和ACLSV、PNRSV、PBNSPaV 3种病毒。     

两种葫芦科病毒的分子检测和致病性研究

 小西葫芦黄化花叶病毒(ZYMV)和黄瓜花叶病毒(CMV)是浙江及其周边地区侵染葫芦科植物最主要的病毒种类。本文通过RT-PCR和基因克隆,获得了侵染南瓜的CMV杭州分离物(HZ01S10)的3'端序列,通过CP氨基酸序列同源性分析,确定其属于CMV亚组I;分别以³²P标记的ZYMV和CMV基因组cDNA作为探针,用RNA点杂交方法定点检测了浙江地区自然感病的葫芦科作物中以上2种病毒的发生情况。ZYMV和CMV在葫芦科作物上的发生表现出显著的季节性差异:夏季CMV发生普遍,只有部分南瓜和甜瓜感染ZYMV;ZYMV则主要发生在秋季,同一时期未检测到CMV。此外,幼苗期接种试验显示:以上2种病毒对西葫芦(早青一代)、丝瓜(中长)、黄瓜(津绿4号)的致病性存在明显差异,供试西葫芦对ZYMV比较敏感,供试丝瓜对CMV更敏感,而供试黄瓜品种对以上2种病毒均表现抗病。复合侵染在丝瓜和西葫芦上加重病害发生程度。     

Incidence of five viruses infecting sweetpotatoes in Uganda; the first evidence of Sweet potato caulimo-like virus in Africa

In a survey of most sweetpotato-growing areas of Uganda, virus-like diseases were observed in all districts surveyed. Out of 338 fields sampled in 35 of the then 42 districts, 219 (65%) had some plants with symptoms. The most common symptoms included vein clearing, mottling, leaf distortion, yellowing, stunting and leaf strapping. Particularly high virus-like disease incidences (means of 34–86%) were encountered in districts around Lake Victoria and in the Rift Valley in southern and western parts of Uganda; particularly low incidences were encountered in the east and north of Uganda. Using four formats of enzyme-linked immunosorbent assay in combination with immunoelectron microscopy and polymerase chain reaction assays, five viruses were identified. Sweet potato feathery mottle virus (SPFMV) and Sweet potato chlorotic stunt virus (SPCSV) were most commonly detected, being found in about 90% of samples. Sweet potato mild mottle virus at 10%, Sweet potato chlorotic fleck virus (SPCFV) at 8% and Sweet potato caulimo-like virus (SPCaLV) at 0·07% were more rarely detected. Most infections were multiple, SPCSV + SPFMV constituting > 90% of all double infections. Triple infections, involving mainly SPFMV, SPCSV and either SPMMV or SPCFV, and quadruple infections of SPFMV + SPCSV + SPMMV + SPCFV were observed in < 10% of the diseased samples. The identification of SPCaLV is the first evidence of its occurrence in Africa.     

Identification of the principal viruses infecting tomato crops in Tunisia

Serological tests have been used to detect viruses associated with tomato in 257 samples collected in different regions in Tunisia, Cap-Bon, Sahel and South during successive seasons. The viruses detected were cucumber mosaic cucumovirus (CMV) and tomato aspermy cucumovirus (TAV), potato Y potyvirus (PVY), tobacco etch potyvirus (TEV) and pepper veinal mottle potyvirus (PVMV), tomato mosaic tobamovirus (ToMV) and tobacco mosaic tobamovirus (TMV), tobacco rattle tobravirus (TRV), alfalfa mosaic alfamovirus (AMV), tomato spotted wilt tospovirus (TSWV), tomato ringspot nepovirus (TomRSV) and potato X potexvirus (PVX). Some were detected in all three regions surveyed, at variable frequencies: TMV, CMV, TEV, PVY, ToMV, AMV, TAV, TSWV and TRV. Others were only detected in two regions (PVMV in Cap-Bon and Sahel and PVX in Sahel and in the south) or one region (TomRSV in Cap-Bon). Movement of individual viruses from one region to another may be due to movement of specific vectors, as in the case of the thrips-transmitted TSWV moving from the south to the north. Some of these viruses were found for the first time in Tunisia.     

侵染冬瓜的病毒病原种类鉴定

本研究在我国主要冬瓜产区采集具有典型病毒病症状的病叶材料105份,根据葫芦科作物上常见的5种病毒病原的CP基因设计特异性引物,对105份待检冬瓜材料进行RT-PCR检测。检测结果表明:5对特异引物可分别在105份待检材料的95份中检测到小西葫芦黄花叶病毒(Zucchini yellow mosaic virus,ZYMV)、西瓜花叶病毒(Watermelon mosaic virus,WMV)、黄瓜花叶病毒(Cucumber mosaic virus,CMV)、番木瓜环斑病毒(Papaya ringspot virus,PRSV)4种病毒,未检测到南瓜花叶病毒(Squash mosaic virus,SqMV);并且发现不同的冬瓜主产区致病的病毒种类有较大差异;同时还发现,在这些待检样品中4种病毒复合侵染现象较普遍,其中以PRSV与WMV组合最常见,占复合侵染现象的31.25%;未发现有4种病毒复合侵染。     

Analysis of the association among three viruses infecting hop in Australia

Associations among Hop latent virus (HpLV), Hop mosaic virus (HpMV), and Apple mosaic virus (ApMV) were assessed in five hop cultivars at four commercial hop-growing regions in Victoria and Tasmania, Australia. The presence or absence of each virus was confirmed by double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Spatial patterns of virus-infected plants were characterized using the Spatial Analysis by Distance IndicEs ( sadie ) system of pattern analysis. The association among viruses (occurrence and covariation) was assessed using the Jaccard similarity index, Spearman's rank correlation coefficient, and sadie . The spatial pattern of plants infected by HpLV and HpMV ranged from random to highly aggregated depending upon the cultivar infected and the mean disease incidence. The spatial pattern of plants infected by ApMV was aggregated in six of the seven plots where ApMV was present. A strong positive association between HpLV and HpMV was found in all cultivars at all locations. This association may be the result of the viruses sharing a common aphid vector species, the presence of one virus enhancing the ability of the aphid vector to acquire the other virus either through transencapsidation or influences on virus titre, or mixed infections within source plants. Significant associations, positive or negative, were found less frequently between HpLV and ApMV, and HpMV and ApMV.     

两种甜瓜病毒寿光分离物的分子检测与鉴定

甜瓜坏死斑点病毒(Melon necrotic spot virus,MNSV)及瓜类褪绿黄化病毒(Cucurbit chlorotic yellows virus,CCYV)近年来在瓜类种植区均大面积发生,危害较为严重,已成为制约甜瓜生产的重要因素。本研究广泛收集疑似感染MNSV及CCYV的甜瓜病叶,从中提取植物总RNA进行RT-PCR扩增,将产物分别连接到pEASYT1Simple克隆载体上,对含有目的片段的重组子进行测序及比对分析。结果显示得到了与预期结果一致的DNA序列,其扩增产物大小分别为673bp(MNSV)和877bp(CCYV)。同源性分析结果表明,MNSV和CCYV寿光分离物的核苷酸序列与中国其他地区或一些国家已报道的分离物同源性达99%~100%。     

上海崇明水仙病毒病病原种类鉴定

 2005~2007年对上海崇明水仙病毒病的种类进行了调查和鉴定。崇明水仙病毒病田间主要表现为花叶、斑驳、黄条和白条等多种症状,以花叶和斑驳为主。采用ELISA和RT-PCR方法,从36个水仙样本上检测到水仙普通潜隐病毒(NCLV)(GenBank登录号:EU200454)、水仙退化病毒(NDV)(GenBank登录号:EU200456);此外,有两类分离物被初步鉴定为新病毒,暂命名为水仙斑驳相关病毒(NMaV)(GenBank登录号:EU182651)和水仙白条相关病毒(NWSaV)(GenBank登录号:EU182652)。4类病毒的总检出率分别为11.1%、13.9%、100%和2.8%,其中NMaV为危害水仙的优势病毒。约20%的样本检测出有2种以上病毒的复合侵染,但是未检测出Potexvirus属的病毒。     

Fungally-transmitted viruses of cereals in the UK1

The distribution of two UK strains of barley yellow mosaic virus has been studied and both have been transmitted experimentally by Polymyxa graminis. cDNA hybridization studies support the suggestion that the strains should be considered distinct viruses. Oat mosaic and oat golden stripe (OGSV) viruses also occur in the UK. OGSV is a furovirus related to wheat soil-borne mosaic furovirus: it has particles of two lengths and a bipartite genome.     

Detection and elimination of viruses infecting sweet potatoes in Hungary

Sweet potato has been grown in Hungary for the last three decades, and its popularity is increasing among farmers and consumers. Its production is hampered by pests and diseases due to poor agricultural practices, such as the use of virus-infected propagation materials. We tested the presence of 15 viruses by PCR and quantitative PCR in 110 sweet potato plants collected from seven regions in Hungary. Seven viruses in single or multiple infections associated with a wide range of foliar symptoms were detected: sweet potato chlorotic stunt virus (SPCSV), sweet potato virus G (SPVG), sweet potato virus C (SPVC), sweet potato feathery mottle virus (SPFMV), sweet potato virus 2 (SPV2), sweet potato leaf curl virus (SPLCV), and sweet potato pakakuy virus (SPPV). This is the first report on the occurrence of the begomovirus SPLCV in sweet potatoes in Hungary. The infectivity and identity of these viruses were confirmed through bioassays (grafting to Ipomoea setosa) and sequencing of the PCR-amplified sections of their genomes, respectively. Due to the necessity for virus-free sweet potato propagation material in Hungary, virus elimination was carried out successfully in five out of six genotypes important for Hungarian farmers using heat treatment and meristem tip culture. All five viruses detected in the plants before heat treatment were removed except SPPV, which persists after heat treatment. Production and strict regulation of virus-free sweet potato propagation materials are recommended to avoid exacerbating the virus situation and protect Hungarian farmers from further losses.     

侵染百合的病毒种类及其检疫重要性

在侵染百合的18种病毒中,有6种病毒为我国禁止进境的检疫性有害生物,在进境的百合中曾检出4种检疫性病毒,因而在进境百合中具有十分重要的检疫重要性。本文介绍了国内外报道的百合病毒种类和最新分类进展以及从进境百合中截获的病毒种类。     

几种重要花生病毒研究新进展

 花生病毒病是影响花生生产的重要病害。近10年来,花生矮化病毒(PSV)、花生条纹病毒(PStV)和番茄斑萎病毒属(Tospovirus)病毒分子生物学研究进展,极大地丰富了对上述病毒基因组结构、遗传变异、进化的认识,以及病毒种、亚组和株系的科学划分。对PSV来说,提出了2个亚组的划分,而我国PSV株系血清学和RNA3全序列的分析,明确它们独自构成第3个新的亚组。对我国和东南亚国家PStV株系CP基因序列同源性的分析,说明在这些国家和地区PStV是单独进化的,形成不同症状类型的株系。Tospovirus属病毒分子生物学研究的深入使得该属病毒从番茄斑萎病毒(TSWV)1种增加到13种,其中侵染花生的病毒达5种,分布于不同的国家和地区。