陕西渭北地区烟草环斑病毒(TRSV)的研究——Ⅰ.病毒的鉴定及其理化特性

自然感染 TRSV 的烟草植株表现矮化,并具有典型的小叶症状。接种结果表明该病毒的寄主范围广泛,可侵染9个科的23种植物,受侵染的植物大多数呈现局部坏死和环斑,某些植物种类到后期还可恢复。病毒的致死温度为65～70℃,稀释限点为10~(-3)～10~(-4),体外保毒期为6～7天。对提纯病毒的研究结果表明:病毒粒子为等轴对称体,直径达26nm,其中有些粒子呈中空状态。病毒制备物经紫外线扫描后可获得典型的核蛋白紫外吸收光谱,其 Amax=260nm,Amin=240nm,A260/280=1.4。病毒降解后所得的核酸和蛋白的紫外吸收最高值分别为260nm 和278nm,而最低值分别为232nm 和250nm。经 PAGE 分析表明外壳蛋白只有一种亚基,其分子量为57000道尔顿;核酸具有2个组分,即 RNA_1和 RNA_2,它们的分子量分别为2.3×10~6和1.4×10~6,其中 RNA_1单独接种无侵染性,RNA_2的侵染性会由于 RNA_1的存在而得到增强。血清学测定表明病株汁液和提纯病毒只与 TRSV 标准抗血清起沉淀反应,而与 CMV、TMV、TNV、TEV 以及 TBRV 抗血清之间没有血清学关系。     

烟草蚀纹病毒(TEV)生物学及理化特性的研究

从自然感病的烟草上分离到烟草蚀纹病毒(TEV)。其寄主范围较宽,经汁液摩擦接种普通烟产生明脉和坏死性蚀纹,在蔓陀萝上为斑驳和畸形,不侵染苋科的千日红及豆科和葫芦科植物。致死温度为53℃,稀释限点为3×10~(-3),体外保毒期为4天。蚜虫传毒试验表明,可经桃蚜进行非持久性传毒。粗提纯的病毒制品在电镜下为稍弯曲的线状粒子,大小约728×12-13nm。病毒粒子经5-40％的蔗糖密度梯度离心后,显示出单一主峰,其紫外吸收值最大为258.5nm,最小为241.7nm,A280/260之比值为1.27。降解病毒所得核酸和蛋白的紫外吸收值分别为最大258nm及273.9nm,最小为233nm及250nm,经PAGE测定其分子量分别为3.16×10~6道尔顿及2.98×10~4道尔顿。用提纯病毒制备所得抗血清效价为1:512;经琼脂双扩散试验证明只与分离的病毒起沉淀反应,而与CMV、TMV、ToRSV、TNV、PVY则无反应。     

烟草花叶病毒卫星病毒(STMV)研究和用于生防的评价

本世纪40年代,Bawden 和 Price 首次在烟草坏死病毒(TNV)为害的烟草和菜豆中发现一种比 TNV(30nm)小的病毒粒体(17nm),当时认为这种小粒体是 TNV 的附属物。直到 Kassania(1962)研究发现这类伴随 TNV 的小粒体自身不能复制,必须依赖 TNV,但其编码自身外壳蛋白与 TNV 没有血清学关系和核酸同源性,才认为这是一种新病毒,称为卫星病毒(Sateuite Virus)。之后,在 TRSV 和 CMV 等十几种病毒中也发现一类小分子量的 RNA,它的复制也依赖于辅助病毒,但不编码自身外壳蛋白,RNA包裹于辅助病毒粒体内,与辅助病毒没有核     

烟草黄斑驳坏死病毒的提纯及抗血清制备

烟草黄斑驳坏死病毒(TYMNV)是近几年来从我国烟草上新分离到的一种病毒,引起烟草植株的黄斑驳坏死症状。本文在分离纯化病毒的基础上,用差速离心法部分提纯了该病毒,其提纯产量约为20mg/公斤病叶。该病毒的免疫原性较弱,采用从次肌肉注射乳化病毒免疫家兔,可制备抗血清。用 SDS—琼脂免疫双扩散法测定,其抗血清效价为1/16。该血清特异性较好,可用于 TYMNV 的田间检测和血清学关系的研究。     

四川晒烟上发现番茄斑萎病毒

在近年来的烟草病害调查中,发现四川什邡、绵竹两县的晒烟上的一种新病害,田间症状主要是叶面的坏死斑点和环纹,退绿黄化斑植株矮化、生长不良。电镜下发现大量近圆形的球状粒体,大小为60～80nm。病毒分离物91—36号能侵染心叶烟和克利夫兰烟,矮牵牛为局部枯斑寄主。分离物的稀释限点为10~(-3)～10~(-4),热钝化温度为45～50℃,体外保毒期为5～6小时。分离物与 TMV、CMV、PVY、PVX 四种抗血清均呈阴性反应,与 TSWV 抗血清呈阳性反应,上述结果表明,四川晒烟上的这种病害的病原为番茄斑萎病毒(TSWV)。这是番茄斑萎病毒在我国烟草上为害的首次报道。     

四川晒烟上发现番茄斑萎病毒(TSWV)

在近年来的烟草病害调查中,发现四川什邡、绵竹两县的晒烟上一种新病害。田间症状主要是叶面的坏死斑点和环纹及退绿黄化斑,植株矮化,生长不良。电镜下发现大量近圆形的球状粒体,大小为60～80毫微米。病毒分离物在心叶烟和克利夫兰烟上产生退绿环斑,矮牵牛为局部枯斑寄主。分离物的稀释限点为10~(-3)～10~(-4),热钝化温度为45～50℃,体外保毒期为5～6小时。分离物与 TMV、CMV、PVY、PVX 四种抗血清均呈阴性反应。与TSWV 抗血清呈阳性反应。上述结果表明,四川晒烟上的这种病害的病原为番茄斑萎病毒(TSWV)。这是番茄斑萎病毒在我国烟草上的首次报道。     

接种PVY^N后烟草叶片SOD活性和MDA含量变化研究

对接种马铃薯Ｙ病毒脉坏死株系后烟草叶片内超氧化物岐化酶活性及其同工酶谱带和丙二醛含量进行了分析。结果表明,接种ＰＶＹＮ后烟草叶片内超氧化物岐化酶活性发生明显变化,接种后１４ｄ内其活性值均较对照增高,其中接种后第８ｄ达高峰值,约比对照增加７２．３％,１４ｄ后超氧化物岐化酶活性开始下降,至接种后１６ｄ约低于对照２８．０％。接种后ＳＯＤ同工酶谱带与对照相比差别不大,仅在接种后第８ｄ出现了一条新带。接种后烟草叶片内丙二醛含量逐渐增加。     

烟草抗性(过敏反应)的遗传和分子表现

烟草对病毒的过敏反应(HR)导致产生新的可溶性蛋白—b 蛋白。我们已经能够证实,这种现象并不是烟草对病毒侵染所特有的,而是烟草对引起过敏反应侵染的一种常见的反应。事实上,当烟草对一种非共存的植物病原菌细菌(Pseudomonas syringae)或真菌(Thiel-aviopsls basicola)有一种过敏反应时,烟叶中就会产生这种新的 b 蛋白。此外,一种导致坏死病斑(Aphelenchoides ritzemabosi)的腐生细菌(P.fluorescens)和线虫也会引起 b 蛋白的合成。烟草对病毒有过敏反应时产生新的蛋白并不是 N.tabacum 特有的现象。除了已研究过     

烟草4种病毒的多重RT-PCR检测方法构建

为有效鉴定烟草的主要病毒,包括烟草普通花叶病毒(Tobacco mosaic virus,TMV)、黄瓜花叶病毒(Cucumber mosaic virus,CMV)、马铃薯Y病毒(Potato virus Y,PVY)和烟草脉带花叶病毒(Tobacco vein banding mosaic virus,TVBMV),建立了一种同时检测这4种病毒的多重RT-PCR检测方法。通过人工接种4种病毒试验,发现TVBMV在混合侵染中受TMV、CMV和PVY的拮抗作用。为提高4种病毒复合侵染下TVBMV的检测灵敏度,筛选出TVBMV中表达水平最高的PIPO基因,利用该基因结合TMV、CMV和PVY的CP基因,基于保守区域设计引物,并优化引物及模板的浓度,在一个PCR反应体系中稳定扩增获得大小分别为700、452、275和235 bp的产物。该方法实现了对多种病毒的同时检测,适用于目前大部分烟区田间病毒复合侵染的监控。     

部分烟区烟草病毒病病原检测及复合侵染分析

为明确主要烟区烟草病毒病的主要病毒种类,采用抗原直接包被ELISA法对重庆、四川、云南、贵州、河南、陕西和甘肃等省市部分烟区采集的266个烟草病毒病样品进行了检测.结果表明,样品中共检测到马铃薯Y病毒(Potato virus Y,PVY)、烟草花叶病毒(Tobacco mosaic virus,TMV)、黄瓜花叶病毒(Cucumber mosaic virus,CMV)、番茄花叶病毒(Tomato mosaic virus,ToMV)及芜菁花叶病毒(Turnip mosaic virus,TuMV)等5种病毒.其中PVY的侵染最普遍,总检出率达75.56%;TMV、CMV、ToMV和TuMV的总检出率分别为65.41%、57.14%、36.84%和34.59%,其中,ToMV和TuMV仅在云南、四川、贵州和重庆样品中检测到.在257个阳性样品中有97个样品受CMV、TMV或PVY单独侵染,其检出率分剔为7.39%、13.23%和17.12%;其余样品均受2种以上病毒复合侵染,其中55.63%的样品中检测到5种病毒复合侵染.田间烟草样品表现出复杂的病毒病症状类型.这些结果说明田间烟草病毒复合侵染现象严重,PVY已成为当前我国烟区的优势毒原.     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press