利用小RNA测序技术鉴定吉林省甘薯病毒

在吉林省7个主要甘薯种植区共采集85份甘薯叶片样品,利用小RNA深度测序技术对混合样品进行检测,经RT-PCR和测序验证,鉴定出样品中存在10种病毒,包括6种RNA病毒和4种DNA病毒。分别是马铃薯Y病毒科马铃薯Y病毒属的甘薯羽状斑驳病毒Sweet potato feathery mottle virus (SPFMV)、甘薯潜隐病毒Sweet potato latent virus (SPLV)、甘薯G病毒Sweet potato virus G (SPVG)、甘薯C病毒Sweet potato virus C (SPVC)、甘薯2号病毒Sweet potato virus 2 (SPV2);长线形病毒科毛形病毒属的甘薯褪绿矮化病毒Sweet potato chlorotic stunt virus (SPCSV);双生病毒科菜豆金色花叶病毒属的甘薯曲叶病毒Sweet potato leaf curl virus(SPLCV);玉米线条病毒属的甘薯无症状1号病毒Sweet potato symptomless virus 1 (SPSMV1);花椰菜花叶病毒科杆状DNA病毒属的甘薯杆状DNA病毒B Sweet potato badnavirus B (SPBV-B)和甘薯隐症病毒Sweet potato pakakuy virus (SPPV)。     

Seed transmission of Sweet potato leaf curl virus in sweet potato (Ipomoea batatas)

Sweet potato leaf curl virus (SPLCV) infects sweet potato and is a member of the family Geminiviridae (genus Begomovirus). SPLCV transmission occurs from plant to plant mostly via vegetative propagation as well as by the insect vector Bemisia tabaci. When sweet potato seeds were planted and cultivated in a whitefly‐free greenhouse, some sweet potato plants started to show SPLCV‐specific symptoms. SPLCV was detected by PCR from all leaves and floral tissues that showed leaf curl disease symptoms. More than 70% of the seeds harvested from SPLCV‐infected sweet potato plants tested positive for SPLCV. SPLCV was also identified from dissected endosperm and embryos. The transmission level of SPLCV from seeds to seedlings was up to 15%. Southern blot hybridization showed SPLCV‐specific single‐ and double‐stranded DNAs in seedlings germinated from SPLCV‐infected seeds. Taken altogether, the results show that SPLCV in plants of the tested sweet potato cultivars can be transmitted via seeds and SPLCV DNA can replicate in developing seedlings. This is the first seed transmission report of SPLCV in sweet potato plants and also, to the authors' knowledge, the first report of seed transmission for any geminivirus.     

甘薯脱毒技术及增产效果研究

作者于１９８８～１９９５年研究了甘薯病毒及甘薯脱毒技术,明确了侵染山东甘薯的主要病毒种类是甘薯羽状斑驳病毒和甘薯潜隐病毒,在国内首次分离侵染甘薯的烟草花叶病毒,探明了其生物学特性。筛选出适合山东甘薯茎尖培养基的最佳激素配比,浓度,ｐＨ值。探索了脱毒薯的增产机理和增产效果,提出了组织培养,茎尖苗检测,脱毒薯速率与推广应用的配套技术规程,培养出徐薯１８等１２个品种的脱毒苗,平均增产４２．９％出干率提高     

国家种质广州甘薯圃病毒种类鉴定及分析

为明确引起国家种质广州甘薯资源圃中病毒病的病毒种类及优势种,为甘薯种质安全保存提供支持,2017年从甘薯资源圃中未脱毒更新的盆栽苗和大田苗中采集155份具有不同病毒病症状的甘薯资源样品,利用PCR和RT-PCR检测技术对这些样品进行了17种病毒的分子检测.155份样品均有病毒检出,包括甘薯羽状斑驳病毒Sweet pot...     

中国甘薯病毒种类的血清学和分子检测

 2009～2010年,从我国18个省（市）采集了176份表现病毒病症状的甘薯样品。利用血清学、PCR和核苷酸序列测定的方法,对上述样品中的病毒种类进行了鉴定。血清学检测结果表明,供试样品中甘薯羽状斑驳病毒（SPFMV）的阳性率最高,达56.3%,其次为甘薯G病毒（SPVG）和甘薯类花椰菜花叶病毒(SPCaLV),阳性率分别为34.1%和33.5%。PCR和核苷酸序列测定结果表明,我国甘薯上至少存在SPFMV、SPVG、甘薯潜隐病毒（SPLV）、甘薯褪绿斑病毒（SPCFV）、甘薯褪绿矮化病毒（SPCSV）、黄瓜花叶病毒（CMV）、甘薯脉花叶病毒（SPVMV）和甘薯卷叶病毒（SPLCV）8种病毒。此外,供试样品中没有检测出甘薯轻斑驳病毒（SPMMV）,是否存在甘薯轻斑点病毒(SPMSV)、SPCaLV和C 6病毒尚不能确定。     

山东甘薯主要病毒的鉴定及多样性分析

为明确山东省甘薯病毒病发生现状,在重病区调查采样,通过鉴别寄主、电镜和分子检测技术明确主要病毒种类;并克隆病毒外壳蛋白基因序列,利用Mega 5.0构建系统进化树进行遗传分析。结果显示,巴西牵牛嫁接甘薯染病枝条后叶片黄化、褪绿及皱缩;病样组织中存在大量600~900 nm的线状病毒粒子和柱状内含体。24份病样中检测到甘薯羽状斑驳病毒、甘薯潜隐病毒、甘薯G病毒、甘薯曲叶病毒和甘薯褪绿矮化病毒5种病毒,其中23份为复合侵染,存在11种侵染类型。遗传分析显示山东省甘薯羽状花叶病毒主要为EA、O和C株系,甘薯潜隐病毒与周边省份分离物相近,甘薯G病毒与中国海南和美国分离物相近,甘薯曲叶病毒分属3个株系。表明山东地区甘薯病毒种类繁多,侵染模式复杂,病毒遗传结构具有多样性。     

Symptoms, aetiology and serological analysis of sweet potato virus disease in Uganda

Sweet potato virus disease (SPVD) is the name used to describe a range of severe symptoms in different cultivars of sweet potato, comprising overall plant stunting combined with leaf narrowing and distortion, and chlorosis, mosaic or vein-clearing. Affected plants of various cultivars were collected from several regions of Uganda. All samples contained the aphid-borne sweet potato feathery mottle potyvirus (SPFMV) and almost all contained the whitefly-borne sweet potato chlorotic stunt closterovirus (SPCSV). SPCSV was detected by a mix of monoclonal antibodies (MAb) previously shown to react only to a Kenyan isolate of SPCSV, but not by a mixture of MAb that detected SPCSV isolates from Nigeria and other countries. Sweet potato chlorotic fleck virus (SPCFV) and sweet potato mild mottle ipomovirus (SPMMV) were seldom detected in SPVD-affected plants, while sweet potato latent virus (SPLV) was never detected. Isolates of SPFMV and SPCSV obtained by insect transmissions together induced typical symptoms of SPVD when graft-inoculated to virus-free sweet potato. SPCSV alone caused stunting and either purpling or yellowing of middle and lower leaves when graft-inoculated to virus-free plants of two cultivars. Similarly diseased naturally inoculated field plants were shown consistently to contain SPCSV. Both this disease and SPVD spread rapidly in a sweet potato crop.     

Effects of sweet potato feathery mottle virus and sweet potato sunken vein virus on sweet potato yields and rates of reinfection of virus-Free planting material in Israel

Yield reductions ofca 50% or more were observed in field plots infected with both sweet potato feathery mottle virus (SPFMV) and sweet potato sunken vein virus (SPSVV) (‘complex’), compared with plots planted with virus-free propagation stocks. No yield reductions were observed in a plot planted with SPFMV-infected cuttings. In plots infected with SPSVV alone, no significant effect on tuber yields was observed in one year, whereas in the second year there was aca 30% reduction in yield compared with virus-free control plants. Reinfection in the field, in the absence of introduced infection sources, was observed only with SPSVV. However, natural spread resulted when SPFMV-infected source plants were introduced. This implies that aphid vectors were present during the growing season, but that SPFMV infection sources were absent from the area.     

我国甘薯脱毒种薯种苗繁育存在的问题及建议

病毒病是甘薯的重要病害, 种植脱毒健康种苗是防治病毒病?提高甘薯产量最有效的方法?近年来, 我国甘薯病毒及其传播介体的发生呈现出新的特点, 传统的脱毒种薯种苗繁育体系不能满足当前甘薯生产的需要?本文综述了当前我国甘薯病毒的种类及危害现状, 分析了我国甘薯脱毒种薯种苗繁育中存在的问题, 对规范和完善我国甘薯脱毒种薯种苗繁育体系提出了建议?     

我国发现由甘薯褪绿矮化病毒和甘薯羽状斑驳病毒协生共侵染引起的甘薯病毒病害

甘薯病毒病害(Sweet potato virus disease,SPVD)是由毛形病毒属(Crinivirus)的甘薯褪绿矮化病毒(Sweet potato chlorotic stunt virus,SPCSV)和马铃薯Y病毒属(Potyvirus)的甘薯羽状斑驳病毒(Sweet potato feathery mottle virus,SPFMV)协生共侵染甘薯引起的病毒病害[1].     

Uneven distribution of two potyviruses (feathery mottle virus and sweet potato latent virus) in sweet potato plants and its implication on virus indexing of meristem derived plants

Abstract

The distribution of two sweet potato potyviruses, FMV and SPLV, was assessed in three plants infected with both viruses and in one plant infected with FMV only. All leaves, the top and basal sections of the main stem, and branch sections were tested by ELISA. Both symptomless leaves and leaves showing symptoms including purple rings, chlorotic spots, mottle or discoloration were found to contain the viruses. However, neither could be detected in every leaf or stem piece. SPLV was found in a lower proportion of leaf and stem samples than FMV. This indicates that the two viruses are either very unevenly distributed within sweet potato plants or that the virus concentration in some parts is below the detectable level. Testing of each leaf is recommended for reliable virus indexing of small, meristem‐derived sweet potato plantlets, if the ELISA method is used. Additional indexing of all ELISA‐negative materials by grafting to susceptible indicator plants is nevertheless still necessary.     

稻曲病菌薄壁分生孢子制备的影响因素分析

本文研究了培养基、温度、振荡速度等因素对稻曲病菌Ustilaginoidea virens薄壁分生孢子产孢量的影响。结果表明,稻曲病菌薄壁分生孢子在培养第7天基本达到最大孢子量;该菌最适宜产孢的培养基为马铃薯煮汁,在煮汁中添加蔗糖可大幅提高产孢量;适宜的产孢温度为26~28℃;静止培养不利于产孢,振荡培养有利于产孢,并表现为转速越高产孢量越多;光照条件对产孢量没有影响。     

中国甘薯病毒的血清学检测

 作者用4种甘薯病毒抗体(IgG),3种血清学方法(DAS-ELISA、Dot-blot-ELISA和ISEM)对北京,江苏、四川、山东四省(市)的253份甘薯病毒病样品进行了检测。结果表明:上述地区甘薯中普遍存在甘薯羽状斑驳病毒(SPFMV)和甘薯潜隐病毒(SPLV),尚难确定是否存在甘薯轻斑驳病毒(SPMMV)和甘薯花叶菜花叶状病毒(Sweet Potato Caulimo-like Virus,SPCLV)。21%的显症样品同上述4种病毒的抗血清不产生反应,显示我国甘薯上尚存在其它病毒。用Dot blot-ELISA和ISEM检测甘薯病毒比用DAS-ELISA灵敏准确。     

Avoiding Secondary Leaf Fall Disease of Rubber by Chemical Defoliation

Abstract

An intensive survey of cultivated plants throughout the island of Montserrat resulted in the identification of a number of viruses. Squash mosaic virus was found in cantaloupe, pumpkin and squash. There were cases of multiple infection of pumpkin and squash by cucumber and squash mosaic viruses. Potato virus Y was recovered from pepper and tomato. Bean yellow mosaic and cowpea mosaic viruses were found in red kidney bean and string bean while cowpea mosaic virus was found in cowpea and broad bean (Jamaica bean). Other viruses that were previously identified on the basis of field symptomatology were confirmed by host range and serology. Viruses were not recovered from sea island cotton or from sweet potato, although field symptoms on the sweet potato are similar to those caused by sweet potato mosaic virus. The leaf tissues of crop plants were inoculated to a wide range of indicator plants. Some of those that reacted systemically were examined by electron microscopy for virus particles and the sap extracted from them was used in serodiagnostic assays for virus identification. This is the first attempt to identify positively the viruses of crop plants on the island.     

First identification of a sweet potato begomovirus (sweepovirus) in Uganda: characterization,detection and distribution

Sweet potato begomoviruses diverge basally from all other begomoviruses and have been named sweepoviruses. In 2009, a sweepovirus was detected for the first time in sweet potato crops in Uganda by using the indicator plant Ipomoea setosa and generic primers in a polymerase chain reaction (PCR). An isolate was cloned and sequenced, the first fully sequenced genome of a sweepovirus from mainland Africa. At the nucleotide level, this isolate differed from other sweepoviruses by at least 13%, discriminating the Ugandan isolate as a new species which has been tentatively named Sweet potato leaf curl Uganda virus (SPLCUV). In infected sweet potato plants, SPLCUV showed an uneven distribution; it was detected more often in samples from the midrib and lamina of middle and lower leaves, and reversion to healthy tissue occurred, especially in shoots of cv. New Kawogo. This appears to be the first report of resistance to a sweepovirus in sweet potato. While it was only detected at relatively low efficiency by PCR, use of I. setosa plants as an indicator of sweepovirus infection in sweet potato plants was as efficient as using real‐time quantitative PCR (qPCR). Storage of dry leaves for 84 days and dried DNA extracts for 21 days did not affect the ability of PCR and qPCR to detect it. Sweepovirus(es) was detected frequently using generic primers in cultivars Ejumula, New Kawogo and 318L in eastern and central Uganda.     

A more sensitive and rapid multiplex RT-PCR assay combining with magnetic nanobeads for simultaneous detection of viruses in sweet potato

An improved multiplex RT-PCR assay combined with magnetic nanobeads (MNB-RT-PCR) was developed for simultaneous detection of four sweet potato viruses, Sweet potato virus G (SPVG), Sweet potato feathery mottle virus (SPFMV), Sweet potato virus C (SPVC) and Sweet potato chlorotic fleck virus (SPCFV). Four primer pairs specific for each virus were designed and the corresponding PCR products were 169, 357, 516 and 900 bp in length for SPVG, SPFMV, SPVC and SPCFV, respectively. The specificity of the method was tested using different combinations of virus templates, and the identities of the amplification products were confirmed by sequencing. The limits of detection for all four viruses by single and multiplex MNB-RT-PCR assays were comparable. The assay was further evaluated using laboratory and field samples compared with a conventional CTAB-RT-PCR assay, and the comparative results showed that the MNB-RT-PCR assay was more rapid and sensitive. These results suggest that the multiplex MNB-RT-PCR assay is an effective and preferable method for virus detection in sweet potato.     

烟粉虱中甘薯双生病毒(sweepoviruses)半巢式PCR快速检测技术的建立与应用

甘薯双生病毒(sweepoviruses)是侵染甘薯的一类重要病毒,通过烟粉虱以持久方式传播,我国甘薯上至少存在8种甘薯双生病毒.本研究根据我国已报道的8种甘薯双生病毒基因组保守区设计了一组引物,建立了单头烟粉虱中甘薯双生病毒的半巢式PCR快速检测方法.特异性和灵敏性分析结果表明,半巢式PCR具有较高的特异性和灵敏性,...