Purification and Properties of the Geminivirus Euphorbia Mosaic Virus

Euphorbia mosaic virus was purified from infected plants of Nicotiana benthamiana. Highest concentrations of virus particles were found in infected plant tissue between 10–12 days after inoculation. The enzyme driselase assisted in purification of the virus particles from the infected tissue yielding about 600 μg/kg of plant material. Purified preparations showed a maximum absorption at 260–263 nm and the ratio of absorption at 260 and 280 nm was 1.4. The viral nucleic acid was digestedby DNase I and S₁ Nuclease but not RNase A. A single coat protein with a MW of 32,000 d and two DNA bands with a MW 0.96 × 10⁶ d (2870 nucleotides) and 0.90 × 10⁶ d (2700 nucleotides) were associated with the purified virus particles. Virus specific DNA was isolated from infected tissue between 7 and 15 days after inoculations.     

Biological and Serological Properties of Strains of Barley Mild Mosaic Virus

The biological and serological properties of two Japanese barley mild mosaic virus (BaMMV) strains (BaMMV-Kal and BaMMV-Nal) and a German BaMMV strain (BaMMV-M) were compared. Mechanical inoculation experiments showed that these three strains differed from one another in their ability to infect specific barley cultivars. BaMMV-Kal and BaMMV-M caused similar symptoms, but BaMMV-Nal clearly differed from them in its symptoms on some barley cultivars. The three BaMMV strains efficiently infected barley plants at 15°C, whereas at 20°C BaMMV-Kal and BaMMV-M also infected many plants but BaMMV-Nal infected only a few. BaMMV-Kal and BaMMV-M were indistinguishable by ELISA, while BaMMV-Nal was distinguished from both. The biological and serological variability reported shows that BaMMV occurs as two distinct strains in Japan.     

Nematode Interactions with Weeds and Sugarcane Mosaic Virus in Louisiana Sugarcane

Weeds did not appear to serve as reservoirs for phytophagous Louisiana sugarcane nematode populations except for Criconemella spp., Meloidogyne spp., Tylenchorhynchus annulatus, and total phytophagous nematode densities were lower on weed-stressed cane and were accompanied by reduced accumulations of free cysteine, proline, and 13 other free amino acids in sugarcane. A significant weed-virus interaction for sugarcane free cysteine accumulation was detected; T. annulatus populations were highly correlated (r = 0.59, P ≤ 0.001) with the weed-induced and virus-induced changes in free cysteine. Sugarcane nematodes interacted differently with the weed and virus stresses and changes in host plant stress-related free amino acid concentrations.     

小麦黄花叶病毒的分离提纯及其血清学等特性

应用梯度离心和超速离心浓缩获得部分提纯的病毒制剂,产量约为7.45g/kg病叶提纯的病毒制剂的紫外吸收曲线呈典型的核蛋白吸收曲线,OD260/OD242和OD260/OD280的比值分别为1.24和1.38。病毒粒子呈线状,宽13—14nm,长度主要分布于250—300nm和550—700nm之间,1000nm以上的粒子也有检到。病毒外壳蛋白仅由一个分子量约为30Kd的亚基组成。在免疫电镜试验中、病毒粒子与日本WYMV抗血清发生强烈的血清学反应。新鲜病叶的超薄切片中可看到大量风轮体和膜状体。     

Purification and Characterization of Indian Cassava Mosaic Virus

The Indian cassava mosaic virus (ICMV) was transmitted by the whitefly Bemisia tabaci and sap inoculation. ICMV was purified from cassava and from systemically infected Nicotiana benthamiana leaves. Geminate particles of 16–18 × 30 nm in size were observed by electron microscopy. The particles contained a single major protein of an estimated molecular weight of 34,000. Specific antiserum trapped geminate particles from the extracts of infected cassava and N. benthamiana plants in ISEM test. The virus was detected in crude extracts of infected cassava, ceara rubber, TV. benthamiana and N. tabacum cv. Jayasri plants by ELISA. ICMV appeared serologically related to the gemini viruses of Acalypha yellow mosaic, bhendi yellow vein mosaic, Croton yellow vein mosaic, Dolichos yellow mosaic, horsegram yellow mosaic, Malvastrum yellow vein mosaic and tobacco leaf curl.     

杭州地区发生的玉米花叶病由甘蔗花叶病毒引起

从杭州地区呈现玉米矮花叶典型症状的玉米病组织中提纯得到大量线状病毒粒子,大多数长度为750?nm。病组织中含有大量风轮状内含体和板状集结体。病毒外壳蛋白为33.6 kD。病毒RNA13’端序列(1.8 kb)与甘蔗花叶病毒(SCMV)同源性最高,达71.5%～99.1%,与高梁花叶病毒(SrMV)同源性次之,为67.8%～68.5%,与玉米矮花叶病毒(MDMV)同源性最低,仅为38.4%～48.4%,从而初步认为此病害由SCMV引起。根据已发表的SCMV外壳蛋白氨基酸序列作亲缘性分析,表明SCMV可分为美国、南非、澳大利亚;德国和中国三大类。     

侵染香蕉的黄瓜花叶病毒株系的血清学特征

香蕉花叶病三类不同症状,即断续条纹类（BS）、连续条纹类（CS）和斑驳类（MM）在田间广泛存在,经过血清学、生物学、核酸斑点杂交和反转录聚合酶链反应,已确定它们都由黄瓜花叶病毒（Cucumberm。。i。virus,CMV）所弓愧f’］。这三类症状分离物在鉴别寄主、粒子形态、粒子电泳相对迁移率以及在西葫芦（CI;curbitafor）和烟草（Nicotianatabacumcv．HV38）上增殖和运转动力学的特征也表现不同［’］。这些不同可能揭示了香蕉三类分离物分属不同的株系。血清学是鉴定和研究CMV株系间亲缘关系的重要依据。大量文献【’,‘1报道…     

玉米矮花叶病毒提纯及特性的研究

改进病毒纯化方法,获得了较高纯度、较强侵染活性的提纯病毒制品。提纯病毒的产量为0.7—1.2mg/100g病叶,病毒粒体大小为720—750×14nm,SDS-聚丙烯酰胺凝胶电泳测得的外壳蛋白分子量为36000道尔顿,用提纯病毒免疫家兔得到较高特异性的抗血清,微量沉淀反应的效价为1/2048,间接ELISA法测出的感病叶汁液的最高稀释倍数为3200—6400倍。     

Properties of Johnsongrass Chlorotic Stripe Mosaic Virus

Physicochemical, biological, and cytopathological properties of Johnsongrass chlorotic stripe mosaic virus (JCSMV) found in Iran were investigated. Virus particles were polyhedral, showed a knobbed surface structure, were c. 30 nm in diameter and had a buoyant density of 1. 359 g/ml in cesium chloride. Virions contained one major protein with a molecular weight of 41 kd and a single species of ssRNA with a molecular weight of 1. 43 × 10⁶ d. Acid hydrolysis of the virus followed by thin-layer electrophoresis gave the following molar percentages of the bases: A: 23. 5, G: 27. 5, C: 26 and U: 23. Separation of nucleotides of the viral RNA using alkaline hydrolysis was not successful. Mechanical inoculation of freshly purified virus or isolated RNA failed to infect Johnsongrass or maize plants. The virus was readily detected by ELISA in seeds from infected plants and young seedlings raised from such seeds, but not in later stages of growth. Ultrathin sections of infected cells showed high concentrations of virus particles in the cytoplasm and vacuoles. Virus-like particles also occurred in the stroma of chloroplasts and mitochondria. Cisternae of endoplasmic reticulum (ER) were often extremely inflated and filled by a fine fibrillar material. Small membrane-associated vesicles were frequently found in ER elements and occurred also in the permuclear space. Based on particle structure, properties of the nucleic acid, molecular weight of the coat protein and cytopathology, the virus resembles carmoviruses. However, lack of mechanical transmissibility is not known for any virus classified with this group. No serological reaction was detected with a total of 30 antisera to carmoviruses and other isometric viruses.     

侵染香蕉的黄瓜花叶病毒株系的形态和生物学特征

对香蕉花叶病广东三个代表分离物的形态和生物学特征进行了较为全面的研究。在六种鉴别寄主上,斑驳类（ＭＭ）和断续条纹类（ＢＳ）分离物侵染较多的寄主种类诱导较为严重的症状,连续条纹类（ＣＳ）分离物侵染能力较弱。电镜观察表明：ＢＳ、ＣＳ和ＭＭ三个代表分离物的粒子呈球状、其粒子直径分别为２２．５、２４．３和２７ｎｍ,纯化的病毒粒子电泳相对迁移率分别为０．７２、０．５６和０．５１,在西葫芦上的增殖速度：不管在子叶或真叶,都是ＭＭ最快、ＢＳ次之、ＣＳ最慢。从西葫芦接种叶运转出接种叶的速度：ＭＭ和ＢＳ相似、ＣＳ明显较慢。在烟草上,三个分离物的运转速度和增殖速度以ＭＭ最快、ＢＳ次之、ＣＳ最慢;而且在烟草上随着接种后时间的延长,三个分离物除ＭＭ维持高浓度的时间较长外,ＢＳ和ＣＳ的都很短。在西葫芦和烟草上提纯产量,ＭＭ类最多、ＢＳ类次之、ＣＳ类最低。     

Molecular Variability and Distribution of Sugarcane Mosaic Virus in Shanxi,China

Background

Sugarcane mosaic virus (SCMV) is responsible for large-scale economic losses in the global production of sugarcane, maize, sorghum, and some other graminaceous species. To understand the evolutionary mechanism of SCMV populations, this virus was studied in Shanxi, China. A total of 86 maize leaf samples (41 samples in 2012 and 45 samples in 2013) were collected from 4 regions of Shanxi.

Results

Double-antibody sandwich (DAS)-ELISA and RT-PCR showed 59 samples (30 samples in 2012 and 29 samples in 2013) to be positive for SCMV, from which 10 new isolates of SCMV were isolated and sequenced. The complete genomes of these isolates are 9610 nt long, including the 5′ and 3′ non-coding regions, and encode a 3063-amino acid polyprotein. Phylogenetic analyses revealed that 24 SCMV isolates could be divided on the basis of the whole genome into 2 divergent evolutionary groups, which were associated with the host species. Among the populations, 15 potential recombination events were identified. The selection pressure on the genes of these SCMV isolates was also calculated. The results confirmed that all the genes were under negative selection.

Conclusions

Negative selection and recombination appear to be important evolutionary factors shaping the genetic structure of these SCMV isolates. SCMV is distributed widely in China and exists as numerous strains with distinct genetic diversity. Our findings will provide a foundation for evaluating the epidemiological characteristics of SCMV in China and will be useful in designing long-term, sustainable management strategies for SCMV.     

玉米抗甘蔗花叶病毒分子标记开发

由甘蔗花叶病毒引起的玉米矮花叶病是我国黄淮海地区玉米生产的重要病害,开发抗矮花叶病基因分子标记是开展抗病分子标记辅助育种的基础。本文基于玉米6．00-6．01区域的“一致性抗甘蔗花叶病毒QTL区间”寻找抗病基因的功能保守域,依据序列多态性开发出抗病分子标记InDel-130和InDel-110,在已知抗性的102份玉米自交系中进行验证。通过分析标记抗病带型和感病带型中的抗病和感病自交系数目,卡平方测验表明标记InDel-130在供试自交系中与抗病性的表现独立无关．而标记InDel-110与甘蔗花叶病毒抗性高度相关,为共显性标记,可用于玉米抗甘蔗花叶病毒种质筛选和分子标记辅助育种。     

Barley Yellow Mosaic Virus: Purification, Electron Microscopy, Serology, and other Properties of two Types of the Virus

From naturally infected barley plants two types of barley yellow mosaic viruses have been isolated in Federal Republic of Germany. Both are identical in morphology, showing a bimodal length distribution (270–289 nm and 568–600 nm), and in symptomatology. Both induce conspicuous cytoplasmic inclusions of the pinwheel type and laminated aggregates, as well as threedimensional crystal-like arrays of membrane material. The types differ, however, in buoyant density, serology, and transmissibility. One is transmissible by soil as well as mechanically (BaYMV-M), and does not react with a Japanese antiserum to the Japanese virus (BaYMV-J). The other type (BaYMV-NM) is only transmissible by soil and reacts with BaYMV-J-antiserum. From mechanically infected plants BaYMV-M was purified, and an antiserum was produced, from soil-infected plants only mixtured BaYMV-NM and -M could be obtained. BaYMV-NM prevailed during winter, but with rising temperatures in spring BaYMV-M was predominant. BaYMV-M and the -M-NM mixture had each two species of nucleic acids (2.7–2.8 × 10⁶ and 1.4–1.5 × 10⁶ d) and two major protein subunit bands were found in SDS-PAGE (35–36 × 10³ and c. 29 × 10³ d).