大豆花叶病毒(SMV)感染大豆品种“Lee”叶片细胞超微结构的研究

 本文对大豆花叶病毒(SMV-H-16)感染大豆品种"Lee"叶片细胞的超微结构进行了连续观察。研究结果证实:用SMV-H-16感染美国大豆品种"Lee"表现症状极轻微,易恢复。其超微结构特征如下:(1)病毒粒体出现于圆柱状和风轮状内含体之后。(2)风轮状内含体从细胞质中逐渐向液泡区伸进。(3)首先在细胞质和液泡膜附近,发现病毒粒体.(4)靠近细胞核处出现一些类似环孔膜板状结构。(5)感染28天后叶片细胞里病毒粒体被束缚在束丝中,附着在液泡膜的内圆面和叶绿体上,此时,风轮状内含体消失。     

甜菜花叶病毒病研究之二——感病细胞超微结构观察

 对不同时期感染甜菜花叶病毒(BtMV)的叶片,进行病理变化系列观察。早期侵染(7天前)的细胞质、细胞器均无变化,随着症状发展,风轮状内含体、束状内含体、细胞核卫星体,细胞质泡囊化旁类似病毒的束状结构,20天达到了高峰,风轮状及束状内含体一直持续两个月还存在。田间样品也观察到了典型的风轮状及束状内含体。细胞核卫星体出现很少。侵染后期,细胞质减少,叶绿体比相应健株提前出现淀粉粒,噬锇颗粒等,基粒片层也提前消解,表现细胞提前衰老的特征。此外细胞内还有许多健株没有的泡状结构。一种为旁壁体,可能与细胞壁加厚有关;一种为多重泡体的叠加,可能是液泡的吞噬作用加强与外源物质(BtMV)侵入有关;另外还有一种可能是过氧化物酶体或线粒体在病毒诱导下泡囊化,其作用不清楚。     

甜菜花叶病毒病研究之二——感病细胞超微结构观察

对不同时期感染甜菜花叶病毒(BtMV)的叶片,进行病理变化系列观察。早期侵染(7天前)的细胞质、细胞器均无变化,随着症状发展,风轮状内含体、束状内含体、细胞核卫星体,细胞质泡囊化旁类似病毒的束状结构,20天达到了高峰,风轮状及束状内含体一直持续两个月还存在。田间样品也观察到了典型的风轮状及束状内含体。细胞核卫星体出现很少。侵染后期,细胞质减少,叶绿体比相应健株提前出现淀粉粒,噬锇颗粒等,基粒片层也提前消解,表现细胞提前衰老的特征。此外细胞内还有许多健株没有的泡状结构。一种为旁壁体,可能与细胞壁加厚有关;一种为多重泡体的叠加,可能是液泡的吞噬作用加强与外源物质(BtMV)侵入有关;另外还有一种可能是过氧化物酶体或线粒体在病毒诱导下泡囊化,其作用不清楚。     

日本和西欧大麦品种对我国大麦黄花叶病的抗感性反应

据39个日本大麦品种和48个西欧大麦品种对中国大麦黄花叶病毒(Ba YMV)分离物的抗病性反应得出,抗日本BaYMV的大麦品种,多数也抗中国的BaYMV,少数为感。感日本BaYMV的大麦品种,多数也感中国的BaYMV,仅少数为抗病,说明中、日两国BaYMV分离物的致病性差异较小。抗西欧BaYMV的大麦品种,对中国的BaYMV,多数品种为感,少数品种为抗。感西欧BaYMV的大麦品种,多数也感中国的BaYMV,少数品种抗。说明中国和西欧两地区BaYMV分离物的致病性差异较大。中国BaYMV分离物的致病力和日本的相似,都比西欧的BaYMV分离物要强。作者还讨论了造成BaYMV致病性差异的可能原因。     

应用A蛋白免疫电镜技术快速检测病株中大麦黄花叶病毒

 用A蛋白免疫电镜技术,检测大麦病汁液中的大麦黄花叶病毒(BaYMV),其捕获抗血清的适宜工作浓度范围很宽,320-20,480倍均能达到满意的结果;抗原孵育条件以室温(约25℃)下30分钟或冰箱(约4℃)中3小时,捕获到的病毒粒子数量较多。应用这项技术,在稀释3,125倍的病汁液中还能检测到BaYMV粒子,比普通免疫电镜方法的灵敏度至少高5倍。BaYMV在病株中的分布以症状明显的花叶中含量最高,黄化叶中较少,茎和根中找不到病毒。利用该技术可以快速而灵敏地进行大麦品种抗病性的鉴定与筛选。本文最后还讨论了BaYMV的稳定性。     

小麦梭条斑花叶病毒(WSSMV)和小麦黄花叶病毒(WYMV)的细胞质内含体的电镜观察

小麦梭条斑花叶病毒(WSSMV)和小麦黄花叶病毒(WYMV)分别感染小麦(Triticum aestivum L.)后所诱发的细胞质内含体和细胞嚣病变几乎完全相同。感病的叶肉细胞、表皮细胞和木质部薄壁细胞的细胞质中都可看到大量风轮体、柱状体、板状集结体和膜状体,其中以叶肉细胞中更为普遍。风轮体成群出现、同一组内风轮体常平行排列,而相邻群间常垂直排列。膜状体的内部常夹杂着许多小囊泡,其四周与内质网呈辐射状相连。在发病初期的心叶叶肉细胞质的液泡附近可看到颗粒状病毒束,而分散的病毒状颗粒则多见于发病中后期坏死的细胞中。感病细胞的叶绿体、线粒体、核、质膜及胞间联丝中均未见病毒状颗粒。感染病毒的细胞中,细胞质丰富、内质网膨大,核糖体增加、小囊泡大量出现,随着病害的加重,叶绿体、线粒体逐渐肿大,基粒缩小、膜破裂、类囊物流入细胞中。     

禾谷多粘菌分离、培养、接种及用于大麦抗黄花叶病的鉴定

 通过禾谷多粘菌Polymyxa graminis L.休眠孢子分离接种感病大麦品种,并进行砂培养,获得13个纯化了的禾谷多粘菌分离物,且其中3个带有大麦黄花叶病毒(BaYMV)。用分别带有BaYMV和大麦温和花叶病毒(BMMV)的英国禾谷多粘菌分离物的游动孢子接种13个中国大麦品种,以及用BaMMV摩擦接种36个中外大麦品种,抗性鉴定结果游动孢子接种与摩擦接种一样,均与田间鉴定结果一致,且大麦对BaYMV的抗性与对BaMMV的抗性一致,从而这2种接种方法可用于大麦品种(系)和育种中间体对BaYMV抗性的快速鉴定和筛选。游动孢子或休眠孢子接种方法还可有效地鉴定大麦对禾谷多粘菌的抗性。     

小麦梭条斑花叶病毒(WSSMV)和小麦黄花叶病毒(WYMV)的细胞质内含体的电镜观察

 小麦梭条斑花叶病毒(WSSMV)和小麦黄花叶病毒(WYMV)分别感染小麦(Triticum aestivum L.)后所诱发的细胞质内含体和细胞嚣病变几乎完全相同。感病的叶肉细胞、表皮细胞和木质部薄壁细胞的细胞质中都可看到大量风轮体、柱状体、板状集结体和膜状体,其中以叶肉细胞中更为普遍。风轮体成群出现、同一组内风轮体常平行排列,而相邻群间常垂直排列。膜状体的内部常夹杂着许多小囊泡,其四周与内质网呈辐射状相连。在发病初期的心叶叶肉细胞质的液泡附近可看到颗粒状病毒束,而分散的病毒状颗粒则多见于发病中后期坏死的细胞中。感病细胞的叶绿体、线粒体、核、质膜及胞间联丝中均未见病毒状颗粒。感染病毒的细胞中,细胞质丰富、内质网膨大,核糖体增加、小囊泡大量出现,随着病害的加重,叶绿体、线粒体逐渐肿大,基粒缩小、膜破裂、类囊物流入细胞中。     

牛蒡矮化类病毒的研究——Ⅲ.病叶组织的超微结构

 对含有牛蒡矮化类病毒(BSV) RNA-1和RNA-2的病叶组织和健叶组织进行了固定、包埋、切片及电镜观察。在含BSV RNA-1及BSV RNA-2的病叶切片中均未观察到病毒颗粒。在有病细胞的旁壁体与健康的不同,病细胞中观察到畸变的旁壁体,有的似风轮状。而健康细胞中未观察到。健叶和病叶细胞的叶绿体和细胞核等细胞器未观察到明显的区别。     

应用单克隆抗体检测大麦黄花叶病毒

作者应用已建立的大麦黄花叶病毒(BaYMV)的4F_(10)单克隆抗体杂交瘤细胞株,经小白鼠腹水生产单克隆抗体,用过碘酸钠法制备了辣根过氧化物酶标记的酶标单克隆抗体。并由此建立了检测大麦黄花叶病毒的标准的双抗体夹心酶联免疫吸附法(DAS-ELISA)。其检测提纯病毒的灵敏度为3.0μg/ml左右,感病大麦叶片汁液的最大稀释度为1:2560,病茎稀释度为1:160。对采自我国7个主要BaYMV发病区感病的样品进行了检测,绝大多数均显示强阳性,只有宝山样品例外。本项试验为BaYMV诊断的标准试剂盒的建立进行了有益的尝试。     

水稻条纹叶枯病细胞病理变化的观察

 利用透射电子显微镜和免疫胶体金标记技术,观察水稻条纹叶枯病病叶细胞病理变化,病毒粒体、病毒外壳蛋白和病害特异蛋白在寄主细胞中的分布。结果表明,病叶叶肉细胞中线粒体增多,细胞核变大,几乎每个细胞中都有蛋白体,叶绿体基粒片层变稀疏和变粗,或被挤压和变细,或叶绿体解体,基粒片层残留于细胞质中。在叶肉细胞和维管束筛管细胞中发现一些内含体和电子密度较高的物体,在高放大倍数下,可以清楚的看出为点状和丝状结构,其直径约为8nm。免疫胶体金标记显示,病毒外壳蛋白和病害特异蛋白存在于叶绿体、细胞质和细胞核以及细胞壁上,但线粒体中没有发现。     

水稻抗病品种单209矮叶片感染白叶枯病的超微结构变化

 水稻单209矮品种的叶片感染白叶枯病菌后,感病细胞超微结构有显著变化。叶绿体膜。系统降解,线粒体肿胀、脊和基质异常,并在感病细孢中常可观察到内陷的质膜和膜系网络结构,此外,在胞质中大量出现颗粒状和纤维状物质。这些物质可能具有抗病功能或者是抗病反应的产物。     

大麦黄花叶病毒(BaYMV)的提纯

 本文提出了一个改进了的大麦黄花叶病毒提纯方法。病大麦叶片在高浓度(0.5M)磷酸钾缓冲液pH7.0(内含0.1% ME,0.01M EDTA)中匀浆,经1/4体积四氯化碳澄清后,病汁液用6% PEG,3% NaCl和1% TritonX-100混合物沉淀,高浓度(0.5M)同种缓冲液(含0.5M尿素,0.1% ME和0.01M EDTA)悬浮,接着进行20%蔗糖垫(含0.3% Triton X-100)超迷离心去除寄主细胞成分,10-40%蔗糖密度梯度离心进一步纯化。所获得的BaYMv提纯制剂A260/A280,A260/A240比值分别为1.20和1.04,纯病毒产量约为5.5-8.0mg/kg病叶。提纯病毒制剂在电镜下看不到有寄主杂质存在。     

Characterisation of BaYMV and BaMMV Pathotypes in France

The reaction of thirty-four barley cultivars from European and Asiatic origin was analysed in six soils infected with barley yellow mosaic virus complex (BaYMV, BaMMV). These soils were selected from 16 sites for their differences in cultivar response. Amongst the six cultivars carrying the ym4 gene (Esterel, Express, Labéa, Majestic, Réjane, Vanoise), only cv Majestic was infected at one site with BaYMV and BaMMV. Concerning BaYMV, three cultivars were infected on all the soils and 19 on none of them. Twelve cultivars were differentially infected depending on the soil. In the case of BaMMV, four cultivars were infected on all the soils and 19 on none of them. Eleven cultivars were differentially infected depending on the soil. ELISA tests revealed the presence, in these soils, of variants of BaYMV and BaMMV that were able to overcome at least seven of the 12 known resistance genes (ym3, ym4, ym6, ym8, ym9, ym10, ym11) and the resistance of three varieties (Tosan Kawa 73, OU1 and Taihoku A) in which the genetic basis is unknown. Amplification by RT-PCR of the N-terminal region for three of BaYMV variants was performed. Nucleotide and amino acid sequences were determined and compared with the corresponding sequence of a common strain of BaYMV-G. A few nucleotide differences were detected between all the French isolates, but there were no strain specific amino acid differences.     

The effects of infection by barley yellow mosaic virus on the yield and components of yield of barley

Infection by barley yellow mosaic virus (BaYMV) was greater in a crop sown in October than in November and in cv. Maris Otter than in cv. Sonja. However, a greater proportion of plants of Sonja than of Maris Otter were infected, and more severely, with the soil-borne fungus vector of BaYMV. Polymyxagraminis. Indifferent years the yield of individual plants of Maris Otter was decreased by 15% and of Sonja by 40%. The spring barley cultivars Athos. Porthos. Georgie and Ark Royal were all infected with BaYMV when sown in autumn in infected soil. Infected winter barley cv. Igri lost up to 50% of yield when this was measured across a naturally infected patch of crop.     

Electron microscopy of plant tissues infected with potato viruses A and S

Electron microscopy of ultrathin sections of plant tissues infected with potato virus A, revealed pinwheel inclusions and electrondense bundles. In tissues infected with potato virus S bundles of particles or accumulations of closely packed black dots were observed.     

A potyvirus isolated from solanaceous hosts

A potyvirus was isolated from Datura stramonium, Lycopersicon esculentum (tomato) and Solanum nigrum in the Yemen. It was transmitted mechanically and by Myzus persicae in a non-persistent manner. Its flexuous rod-shaped particles had a mean length of 719 nm and some of its pinwheel inclusion bodies in infected Nicotiana clevelandii leaves were unusual in that they were dichotomously branched. The virus infected various solanaceous species, but the symptoms it induced were distinct from those of pepper veinal mottle (PVMV) and potato Y viruses. Its particles were purified from N. glutinosa and their coat protein had an atypically high molecular mass a potyvirus of 41·5 kDa. They showed a distant serological relationship to those of PVMV and potato virus V in ISEM decoration tests, but did not react with antisera to particles of any other potyvirus tested. The virus has been tentatively named tomato mild mottle virus.     

宿根矮化病菌对甘蔗品质及茎、叶超微结构的影响

 甘蔗宿根矮化病(Ratoon Stunting Disease, RSD)是由Leifsonia xyli subsp.xyli (Lxx)引起的,是目前世界所有植蔗地区危害性极大的病害之一。本实验以甘蔗品种新台糖22号(ROC22)健康植株为对照,感染RSD植株为处理,观察和测定RSD侵染甘蔗引起的蔗株农艺性状、蔗糖分以及茎、叶超微结构的变化。结果表明:(1)感染RSD种茎的出苗率比对照减少2.94个百分点;株高比对照下降28.85 cm;茎径比对照减少0.28 cm;节间长度比对照减短3.50 cm;单茎重比对照低0.36 kg。(2)感染RSD植株的蔗糖分低于对照0.9个百分点(绝对值)。(3)利用透射电镜技术对感染RSD植株茎、叶细胞超微结构进行观察表明,叶片叶肉细胞、维管束鞘细胞及茎细胞内的细胞器及细胞核都发生了明显的病理变化。与健康叶片相比,叶绿体变形,叶绿体基质片层大部分消解,基粒结构消失,叶绿体外膜和内膜剥离。线粒体形态异常,有的肿大、内嵴模糊,严重者内嵴消失并空泡化,仅剩未被消解的残骸;细胞核形态变为不规则,核膜破裂,染色质分布不均匀,呈降解状态。在感染RSD甘蔗茎维管束导管细胞内积累有大量的电子致密物质,细胞壁有不同程度的溶解和断裂,这可能和RSD病原细菌侵染有关。以上结果表明:RSD侵染甘蔗后,可能导致光合效率下降,对水分和营养物质的运输能力降低,从而导致甘蔗品质和产量的降低。     

Occurrence of potyvirus and potexvirus infections in black bryony (Tamus communis) in Devon, UK

Leaf samples of black bryony (Tamus communis L.) from Devon, UK, showing various virus-like symptoms contained potyvirus-like particles (normal length c. 790 nm) and cytoplasmic cylindrical (pinwheel) inclusions. In immunoelectron microscopy, particles of most samples reacted with antiserum to dioscorea greenbanding mosaic virus, a potyvirus isolate from Dioscorea rotundata in Togo which is related to yam mosaic virus from the Ivory Coast. Potyvirus particles were not transmitted by sap or aphids (Myzuspersicae) from infected black bryony to black bryony seedlings or Nicotiana benthamiana. One sample from a symptomless plant of black bryony contained a potexvirus which formed massed virion aggregates in the cytoplasm of cells of black bryony, Nicotiana benthamiana and N. megalosiphon. Virions of the potexvirus (normal length 553 nm) contained a coat protein with an apparent molecular weight of 27.7 kd. The potexvirus differed from an Italian potexvirus isolate from black bryony by a serological differentiation index of 4 and gave only weak or no reactions with 23 other antisera to potexviruses, including dioscorea latent virus. The potexvirus caused systemic symptoms in only a few host plants and could be transmitted back to black bryony in which it caused no symptoms. It is provisionally named tamus latent virus.