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1.
为进一步明确病毒与寄主间的相互作用关系,通过同源比对在烟草细胞中克隆到具有m型硫氧还蛋白(m-type thioredoxin)特征的基因,暂命名为Nt Trm。利用原生质体瞬时转化技术、病毒诱导的基因沉默技术(VIGS)、半定量-PCR以及Northern blot检测技术研究Nt Trm的表达以及Nt Trm表达与PVY积累的关系。结果表明,在PVY接种10 d后红花大金元叶片中Nt Trm表达明显上调;在本氏烟草叶片中Nt Trm下调显著促进了PVY在烟草叶片中的积累;而在烟草原生质体中Nt Trm过量表达则会明显抑制病毒RNA的积累。初步说明烟草细胞内编码m型硫氧还蛋白的基因受PVY侵染而被诱导表达,这类基因的上调表达可能影响PVY在烟草细胞中的侵染。   相似文献   

2.
1 东北地区烟草马铃薯Y病毒病发生规律及防治技术研究该项目鉴定了我国烟草上的PVY共有 4个株系 :PVYO(普通株系 )、PVYN(脉坏死株系 )、PVYNS(茎坏死株系 )和PVYC(点刻条斑株系 ) ,以PVYN 为优势株系。利用CORESTA PVY合作小组提供的国际鉴别寄主 ,室内外测定比较了我国的PVYN 与国际上已报道的PVY各株系的差异 ,认为我国PVYN 与欧洲 3号株系极相似 ,而与美国的两个株系MsNr和VAM B及欧洲的其它株系差异较大 ;开展了PVYN 分子生物学研究 ,克隆获得了PVYN 的复制酶基因 (PVYN NIb)和PVYN 的外壳蛋白基因 (PV…  相似文献   

3.
马铃薯Y 病毒(Potato virus Y,PVY)是危害烟草的重要病害, 种植抗病品种是经济有效的防治措施。分子标记辅助选择可提高抗病育种效率。来源于X-射线诱变的Virgin A Mutante(VAM) 的隐性抗PVY 基因位点(va)被广泛应用于烟草抗病育种。为了提高va 位点的育种利用效率, 根据烟草隐性抗PVY 基因(感病基因)eIF4E-1 基因序列, 设计特异扩增的引物CF2GR11,开发eIF4E-1 基因的分子标记, 并检测了该标记与抗性的遗传距离和在常见烟草资源中的适用性。CF2GR11 在云烟87、红花大金元和K326 等感PVY 品种可扩增出500 bp 产物, 在NC102、NC55 和K326PVY 等抗病品种无扩增条带。以抗、感PVY 亲本构建的101 个F2 单株为定位群体, 遗传连锁分析表明, CF2GR11 标记与烟草PVY 感病基因的遗传距离为0.99 cM。对46 份PVY 抗性明确的栽培烟草资源的检测表明, 供试资源的标记检测结果与抗性的吻合度为100%, 表明CF2GR11 标记适用性高。该目的基因标记可用于抗PVY 育种的辅助选择和抗PVY 资源的鉴定。   相似文献   

4.
  背景和目的  从作物种质资源中进行等位基因鉴定,特别是优异等位基因的发掘和应用,是使种质资源加速转变为基因资源的关键所在。  方法  采用苗期汁液摩擦接种的方法,对烟草种质资源的马铃薯Y病毒(Potato virus Y,PVY)抗病性进行鉴定;通过烟草隐性抗PVY基因eIF4E1(又称为感PVY基因eIF4E1)等位性测验、等位基因分子标记检测和RT-PCR扩增测序,对PVY抗病资源进行基因型分析。  结果  (1)从收集到的900多份来自国内外的烟草种质资源中筛选出19份高抗PVY资源。(2)根据等位性测验结果推断19份抗源所具有的PVY抗性均由eIF4E1基因所控制。(3)等位基因分子标记检测和RT-PCR扩增测序结果将19份抗源的eIF4E1基因区分为4种突变类型。  结论  本研究结果丰富了我国对抗PVY烟草种质资源的筛选和利用的内容,为后续烟草PVY抗性优异等位基因的发掘和育种利用提供了基础材料和信息支撑。   相似文献   

5.
  背景  病毒诱导的基因沉默(virus-induced gene silencing,VIGS)是植物抗病毒侵染的一种自然机制。  方法  以马铃薯Y病毒(Potato virus Y,PVY)脉坏死株系(PVYN)的外壳蛋白(coat protein, CP)基因为靶向序列,构建烟草脆裂病毒(Tobacco rattle virus,TRV)介导的基因沉默表达载体pTRV2-CP,转化农杆菌GV3101后,与pTRV1-GV3101混合成TRV: : CP(OD600 0.4~0.6)喷施处理剪叶后的烟苗,测定其侵染效率。人工接种PVY于对照及TRV: : CP处理的烟苗,RT-qPCR检测、表型观察和小区试验评价TRV介导的VIGS体系对PVY侵染的沉默效果。  结果  ① 与TRV: : 00相比,接种PVY 35 d时,TRV: : CP处理的烟株中PVY累积量减少了72.8%;②VIGS表达载体45 d内能有效表达;③温室盆栽和田间小区试验TRV: : CP处理对PVY防治效果分别达到85.12%和73.08%。  结论  研究建立的VIGS体系能够沉默PVY CP基因的表达,有效防治烟草马铃薯Y病毒病,为PVY的防治提供了新的方法。   相似文献   

6.
用血清学方法对烟草病毒进行检测,同时进行生物学测定和电镜观察,研究结果表明:现山东烟区烟草病毒病的流行种类与以前的报道有较大改变。其流行趋势是马铃薯 Y 病毒病(PVY)由次要病害上升为主要病害,黄瓜花叶病(CMV)依然严重,且病毒的复合感染加重。烟草黄斑坏死病(PVY—T)和烟草脉带花叶病(TVBMV)在山东省首次发现。  相似文献   

7.
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。  相似文献   

8.
为明确Rubisco酶小亚基(Rubisco small subunit,RbcS)在烟草抵抗主要病毒侵染胁迫中的作用,以本氏烟为研究材料,利用qRT-PCR、Western blot和瞬时表达体系对烟草RbcS基因在TMV、CMV和PVY侵染中的调控作用进行系统分析。结果表明,3种病毒侵染本氏烟均引起NbRbcS在mRNA水平和蛋白水平上下调,瞬时过表达NbRbcS,病毒拷贝数均显著降低。而沉默NbRbcS,TMV、CMV和PVY拷贝数分别达到阴性对照的11.12、9.57和17.76倍。对PVY引起的斑驳叶片中深绿色和浅绿色区域分别进行qRT-PCR分析发现,在浅叶区NbRbcS mRNA的表达量只有深叶区的49.10%,但PVY的拷贝数却达到了深叶区的5.18倍。以上研究表明,RbcS大量表达可增强烟草对病毒的防御能力,烟草RbcS基因可作为潜在的抗病毒基因利用。  相似文献   

9.
烟草PVY Real-Time PCR定量检测体系的建立及应用   总被引:2,自引:0,他引:2  
马铃薯Y病毒是近年来危害烟草生产的重要病毒之一,严重影响烟草的产量与品质。本研究利用DNAMAN软件对GenBank数据库中已登录的马铃薯Y病毒(Potato virus Y,PVY)全基因组序列进行序列比对,设计引物,以烟草肌动蛋白基因为内参,建立了烟草PVY的实时定量检测体系。获得的real-time PCR扩增基线平整,指数扩增明显,斜率大;稳定性和重现性好,变异系数小;循环阈值与PCR起始模板量对数之间存在良好的线性关系。与DAS-ELISA相比,该方法具有高效、灵敏、特异性强等优点,为从分子生物学水平上检测烟草中PVY提供了新的技术手段。  相似文献   

10.
[背景和目的]在栽培烟草中,真核生物翻译起始因子(Eukaryotic translation initiation factor 4E1,eIF4E1-S)的缺失或突变能够抗马铃薯Y病毒(Potato virusy,PVY)侵染.为了解烟草野生种eIF4E1-S同源基因的多样性和PVY抗性状况,预测野生种含有抗PVY...  相似文献   

11.
Microencapsulation is a relatively new technology that is used for protection, stabilization, and slow release of food ingredients. The encapsulating or wall materials used generally consist of starch, starch derivatives, proteins, gums, lipids, or any combination of them. Methods of encapsulation of food ingredients include spraydrying, freeze‐drying, fluidized bed‐coating, extrusion, cocrystallization, molecular inclusion, and coacervation. This paper reviews techniques for preparation of microencapsulated food ingredients and choices of coating material. Characterization of microcapsules, mechanisms of controlled release, and efficiency of protection/ stabilization of encapsulated food ingredients are also presented.  相似文献   

12.
The monograph deals with a critical review of the recent research work and development on ramie, a long vegetable bast fibre. The review is divided into two parts. Part I discusses the progress of recent work on ramie, chemical components like fibre degumming, its effects on fibre composition, chemical constituents, i.e. hemicellulose, cellulose, non-cellulosic and mineral matters. Besides various chemical properties of native and modified fibres such as accessibility, infrared, cellulose I–V, DP, grafting, cross linking and resin finishing and dyeing etc. are dealt with.  相似文献   

13.
Epicuticle, isolated from wool via the Allwörden reaction, was examined by electron microscopy and analysed chemically. It is proteinaceous; lipids and carbohydrates could not be detected. The component amino acids are: cystine, glycine, glutamic acid, serine, valine, alanine, lysine, α-amino-adipic acid, and threonine. A tentative model for the epicuticle is proposed.  相似文献   

14.
Mycotoxins in botanicals and dried fruits: A review   总被引:1,自引:0,他引:1  
Botanicals are used in many countries for medicinal and general health-promoting purposes. Numerous natural occurrences of mycotoxins in botanicals and dried fruits have been reported. Aflatoxins or ochratoxin A (OTA) have been found in botanicals such as ginseng, ginger, liquorice, turmeric, and kava-kava in the USA, Spain, Argentina, India, and some other countries, while fumonisins have been found in medicinal wild plants in South Africa and in herbal tea and medicinal plants in Turkey. Zearalenone was identified in ginseng root. Dried fruits can be contaminated with aflatoxins, OTA, kojic acid, and, occasionally, with patulin or zearalenone. One main area of concern is aflatoxins in dried figs; bright greenish yellow fluorescence under ultraviolet light is associated with aflatoxin contamination. OTA in dried vine fruits (raisins, sultanas, and currants) is another concern. There are also reports of aflatoxins in raisins and OTA in dried figs, apricots, dried plums (prunes), dates, and quince. Maximum permitted levels in the European Union include 4 µg kg-1 for total aflatoxins in dried fruit intended for direct consumption and 10 µg kg-1 for OTA in dried vine fruit. This review discusses the occurrence of mycotoxins in botanicals and dried fruits and analytical issues such as sampling, sample preparation, and methods for analysis. Fungal contamination of these products, the influence of sorting, storage, and processing, and prevention are also considered.  相似文献   

15.
The aim of the present review article is to summarize the available information related to the availability, production, chemical composition, pharmacological activity, and traditional uses of Avena sativa to highlight its potential to contribute to human health. Oats are now cultivated worldwide and form an important dietary staple for the people in number of countries. Several varieties of oats are available. It is a rich source of protein, contains a number of important minerals, lipids, β-glucan, a mixed-linkage polysaccharide, which forms an important part of oat dietary fiber, and also contains various other phytoconstituents like avenanthramides, an indole alkaloid-gramine, flavonoids, flavonolignans, triterpenoid saponins, sterols, and tocols. Traditionally oats have been in use since long and are considered as stimulant, antispasmodic, antitumor, diuretic, and neurotonic. Oat possesses different pharmacological activities like antioxidant, anti-inflammatory, wound healing, immunomodulatory, antidiabetic, anticholesterolaemic, etc. A wide spectrum of biological activities indicates that oat is a potential therapeutic agent.  相似文献   

16.
Phytoestrogens are polyphenols similar to human estrogens found in plants or derived from plant precursors. Phytoestrogens are found in high concentration in soya, flaxseed and other seeds, fruits, vegetables, cereals, tea, chocolate, etc. They comprise several classes of chemical compounds (stilbenes, coumestans, isoflavones, ellagitannins, and lignans) which are structurally similar to endogenous estrogens but which can have both estrogenic and antiestrogenic effects. Although epidemiological and experimental evidence indicates that intake of phytoestrogens in foods may be protective against certain chronic diseases, discrepancies have been observed between in vivo and in vitro experiments. The microbial transformations have not been reported so far in stilbenes and coumestans. However, isoflavones, ellagitanins, and lignans are metabolized by intestinal bacteria to produce equol, urolithins, and enterolignans, respectively. Equol, urolithin, and enterolignans are more bioavailable, and have more estrogenic/antiestrogenic and antioxidant activity than their precursors. Moreover, equol, urolithins and enterolignans have anti-inflammatory effects and induce antiproliferative and apoptosis-inducing activities. The transformation of isoflavones, ellagitanins, and lignans by intestinal microbiota is essential to be protective against certain chronic diseases, as cancer, cardiovascular disease, osteoporosis, and menopausal symptoms. Bioavailability, bioactivity, and health effects of dietary phytoestrogens are strongly determined by the intestinal bacteria of each individual.  相似文献   

17.
为解决苎麻在乙二醇有机溶剂脱胶中纤维易被氧化而导致性能下降的问题,在乙二醇溶剂中添加助剂蒽醌对苎麻进行脱胶,并对蒽醌不同添加量下制得的纤维进行结构和性能表征。结果表明:纤维中半纤维素含量随蒽醌添加量的增加而升高,纤维的聚合度、结晶度、物理力学性能先升高后降低,纤维的残胶率和线密度先降低后升高;当蒽醌质量分数为0.3% 时,这些性能均达到最佳值,此时纤维的聚合度、结晶度、制成率、断裂强度、断裂伸长率、断裂功比不加蒽醌时分别提高了7.32%、20.53%、1.46%、9.55%、6.89%、33.33%,纤维的残胶率、线密度比不加蒽醌时分别降低了17.91%、7.24%。  相似文献   

18.
We investigated the population growth of the khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae) on seven groups of commercially available non-grain commodities. Six powdered spices were used in the first group of experiments: black pepper, clove, nutmeg, allspice, cinnamon and turmeric. The second group of the tested commodities included seven animal products: powdered cow milk, powdered pork zelatin, sheeps’ wool, goat’s skin, ducks’ feathers, dry dog food and dry cat food. The third group of commodities was consisted of six herbs: oregano, spearmint, basil, coriander, laurel and marjoram. The fourth group of commodities contained ten pulses: chickpeas, lentil, split peas, black-eyed peas, beans, soybean flour and whole kernels, lima beans, mung bean, and broad beans. The fifth group comprised six dried fruits: Corinthian currants, sultanas, banana chips, melons, apricots and figs. The sixth group was consisted of five non-grain commodities: cottonseed cake, tobacco, black tea, Turk kahvesi and potato flour. The seventh group included seven nuts: sunflower seeds, pumpkin seeds, pistachios, roasted chickpeas (yellow), almonds, hazelnuts and walnuts. Finally, six cracked containment categories (0% cracked kernels, 5% cracked kernels and 95% intact kernels, 10% cracked kernels and 90% intact kernels, 25% cracked kernels and 75% intact kernels, 50% cracked kernels and 50% intact kernels and 100% cracked kernels) from five pulses were tested: chickpeas, black-eyed peas, mung bean, soybean and split peas. The highest progeny production (3.01 individuals per vial) was recorded on powdered cow milk. On pistachios, split peas, sunflower seeds, soybean flour, pumpkin seeds, walnuts, almonds and coriander, T. granarium built high population densities rapidly, while on roasted chickpeas, cottonseed cake, hazelnuts, chickpeas, dog food and lentils, its population growth was much less. Broad beans, melons, figs, lima beans, beans, Corinthian currants, pork zelatin and potato flour were less suitable diets for the development of this species. On black pepper, clove, nutmeg, allspice, cinnamon, turmeric, sheeps’ wool, goat’s skin, ducks’ feathers, cat food, sultanas, banana chips, apricots, tobacco, black tea, Turk kahvesi, oregano, spearmint, basil, laurel and marjoram, no progeny production was recorded. The proportion of 100% cracked black-eyed peas or mung beans was more suitable for the population growth of T. granarium. Also, the percentages of 50% cracked chickpeas or 10% cracked soybeans enhanced the development of the species, in comparison with the whole kernels of each pulse. Our study indicated that several non-grain commodities are beneficial for the population growth of T. granarium, a fact that should be seriously taken into account in international trade, as this pest may utilize them as “vehicles” of expansion.  相似文献   

19.
Nanotechnology is developing rapidly and, in the future, it is expected that increasingly more products will contain some sort of nanomaterial. However, to date, little is known about the occurrence, fate and toxicity of nanoparticles. The limitations in our knowledge are partly due to the lack of methodology for the detection and characterisation of engineered nanoparticles in complex matrices, i.e. water, soil or food. This review provides an overview of the characteristics of nanoparticles that could affect their behaviour and toxicity, as well as techniques available for their determination. Important properties include size, shape, surface properties, aggregation state, solubility, structure and chemical composition. Methods have been developed for natural or engineered nanomaterials in simple matrices, which could be optimized to provide the necessary information, including microscopy, chromatography, spectroscopy, centrifugation, as well as filtration and related techniques. A combination of these is often required. A number of challenges will arise when analysing environmental and food materials, including extraction challenges, the presence of analytical artifacts caused by sample preparation, problems of distinction between natural and engineered nanoparticles and lack of reference materials. Future work should focus on addressing these challenges.  相似文献   

20.
中美主要烟草品种亲源分析与烟草育种   总被引:30,自引:7,他引:23  
本文分析了中美300多个烤烟,80多个晒晾烟主要育成品种的亲源关系,从中可以看出,品质与抗病育种是烟草育种的主体,由Orinoco衍生的Hicks、Virginiabrightleaf和400及后来育成的NC95、Coker139和Coker319等是烤烟品质育种和抗病育种的主体亲本;由WhiteBurley衍生的Kentucky16、Burley21和由MDRobinson育成的Maryland64、Maryland609分别是白肋烟与马里兰烟品质、抗病育种的主体亲本;烟草抗黑胫病、青枯病、根结线虫病、根黑腐病、烟草普通花叶病和野火病的抗源分别来自Florida301、TI448A、TI706、N. debnexyiN. glutinosaN. longiflora等原始栽培品种或野生种。美国烟草育种经历了从品质到多抗,再到综合优良性状改良的阶梯式发展过程。而我国优质、多抗育种起步较晚,仍存在品质与抗性、品质与易烤性关系研究较少,外源优良基因利用较少,遗传基础狭窄等问题,本文就近期烟草育种的目标和途径进行了初步探讨。   相似文献   

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