十字花科蔬菜CMV类群与株系划分初步研究

陕西主要菜区十字花科蔬菜上的ＣＭＶ分为５个类群。其中的Ａ类群侵染十字花科植物为主，可区分为轻花叶、中度花叶和重花叶３个株系。当前田间发生以轻花叶株系为主，占６９．９％。     

Spread and control of Cucumber Mosaic Virus in gladiolus

Cucumber mosaic virus (CMV) and bean yellow mosaic virus are the most prevalent viruses in gladiolus fields in Israel. Factors affecting infection were studied, as a basis for the buildup of virus-tested propagation material. Marked differences in the susceptibility of gladiolus cultivars to aphid-borne infection were observed, both in field experiments and in test aphid inoculations. Cultivars ‘Euro-vision’ and ‘Trader Horn’ were resistant, while ‘Peter Pears’ and ‘Commando’ were highly susceptible. The aphid that landed most frequently on gladiolus wasMacrosiphum euphorbiae. In test inoculationsM. euphorbiae andAphis gossypii efficiently transmitted CMV from gladiolus to gladiolus, but did not transmit CMV from four other source plants. In field experiments, only those gladioli planted close to infected gladiolus sources became infected. Oil sprays in combination with coarse nets controlled CMV infection in the field efficiently.     

抑病毒菌素对黄瓜花叶病毒的作用效果初报

危害植物的病毒种类繁多,造成的损失惨重。在尚无良好的化学农药的情况下,国内外在抗病毒物质研究方面,取得了一定的进展［１～４］。据报道部分抗病毒菌素对植物病毒病的抑制和延缓病害发生具有一定作用［１］,但仍然无法应用于田间病害的防治上。为此,多年来作者致力于抗病毒微生物菌株的筛选和试验研究工作,发现Ｐｅｎｉｃｉｌｉｎｓｐ．的代谢产物对黄瓜花叶病毒（Ｃｕｃｕｍｂｅｒｍｏｓａｉｃｖｉｒｕｓ,ＣＭＶ）作用效果良好。试验结果如下。１　材料与方法１．１　试验材料　寄主为番茄和菜豆;ＣＭＶ为本试验室由感病黄瓜上…     

Cauliflower Mosaic Virus Isolate NY8153 Breaks Resistance in Arabidopsis Ecotype En-2

ABSTRACT Arabidopsis thaliana ecotype En-2 was previously shown to be resistant to cauliflower mosaic caulimovirus (CaMV) isolate CM4-184. In this study, En-2 plants were screened with eight other isolates of CaMV to identify viruses capable of overcoming resistance and to determine if the mechanism of resistance was the same for each virus. En-2 resistance to most CaMV isolates was mediated by the same mechanism, i.e., preventing virus long-distance movement. One CaMV isolate, NY8153, was found that produced a severe systemic infection on En-2 plants. In addition, the CM1841 isolate was able to spread systemically through En-2 plants, to a limited extent, without producing visible symptoms. These data indicate that the resistance shown by En-2 plants is not an all-or-none phenomenon. En-2 plants were susceptible to turnip mosaic potyvirus, suggesting that resistance is specific to CaMV.     

Further identification of Hippeastrum Mosaic Virus

Infectious virus was isolated fromHippeastrum plants by density gradient centrifugation and examined with the electron microscope. The average lengths of the flexuous particles were 643±24 nm.Samenvatting Infectieus virus kon worden geïsoleerd uitHippeastrum-planten die mozaïekverschijnselen vertoonden, door middel van centrifugeren in een dichtheidsgradiënt. Het materiaal werd bekeken in een elektronenmicroscoop en gefotografeerd. De gemiddelde lengte van de buigzame staafies van hetHippeastrum-mozaïekvirus, berekend uit 600 metingen, bedraagt 643±24 nm.     

嫁接西瓜的大棚地杂草黄瓜绿斑驳花叶病毒染病性研究初报

为了明确棚栽嫁接西瓜黄瓜绿斑驳花叶病毒发病地杂草染病情况,采集3个镇(街道)5个村的发病地杂草样本进行种类识别与酶联免疫双抗体夹心(DAS-ELISA)法检测。结果发现82份杂草有18科39种,其中37种杂草78个样本染病,染病率分别为94.8%和95.1%;且在染病的杂草中有12种杂草表现着不同程度的黄瓜绿斑驳花叶病毒疑似症状,以繁缕症状表现最早,也较严重。说明棚栽西瓜田内杂草种类繁多,且很多都能感染或携带黄瓜绿斑驳花叶病毒。     

RNA 2 of Cucumber Mosaic Virus Subgroup I Strain NT-CMV is Involved in the Induction of Severe Symptoms in Tomato

A selection of cucumber mosaic virus (CMV) subgroup I strains originating from Asia and Fny-CMV isolated in USA were studied for their interaction with tomato plants. All strains caused mosaic, fernleaf expression and stunting of tomato plants. Symptom expression was relatively mild after infection with Fny-CMV, T-CMV, Le-CMV and MB-CMV, whereas strains PRC-CMV, NT-CMV and K-CMV caused more severe symptoms. Biologically active clones of NT-CMV RNAs 2 and 3 were generated to construct pseudorecombinant viruses with Fny-CMV to map the symptom determining RNA. The pseudorecombinant FNF-CMV (RNAs 1 and 3 from Fny-CMV, RNA 2 from NT-CMV) showed a similar phenotype on tomatoes to those caused by NT-CMV, whereas FFN-CMV (RNAs 1 and 2 from Fny-CMV, RNA 3 from NT-CMV) induced symptoms comparable to Fny-CMV. The data indicate that CMV RNA 2 of NT-CMV is involved in the induction of severe symptoms in tomato plants.     

嘧肽霉素对烟草花叶病毒抑制作用研究

嘧肽霉素和烟草花叶病毒(TMV)等体积混合后接种,对心叶烟的枯斑抑制率为96.5%,对系统寄主NC89的防效为84.9%。在接种病毒前24 h喷施药剂,枯斑抑制率和对系统寄主的防效分别为75.4%和69.5%。接种病毒后24 h喷药试验表明,药剂能在一定程度上抑制进入植株体内病毒的增殖。药剂与病毒混合处理后电镜观察,病毒粒子有断裂现象,混合时间越长,破坏作用越强。嘧肽霉素对TMV具有较强的体外钝化作用,且是不可逆的。     

Comparison and differentiation of Wheat Yellow Mosaic Virus(WYMV), Wheat Spindle Streak Mosaic Virus (WSSMV) and Barley Yellow Mosaic Virus (BaYMV) isolates using WYMV monoclonal antibodies

Twelve monoclonal antibodies (MAbs) were obtained by immunizing mice with a French isolate (F1) of wheat yellow mosaic virus (WYMV). Three of these (3D12, 2C1, 6C3) belong to the IgM class and the nine others to the IgG class (3D8, 3H1, 2B8, 1F2, 3C10, 4F12, 3H9, 1G5, 54). In antigen-coated plate (ACP) ELISA and indirect double antibody sandwich (IDAS) ELISA, all MAbs recognize the WYMV (F1) both in the form of purified particles and in wheat leaf extract. The analysis of numerous French isolates of WYMV shows a variable reactivity with MAbs 3D8, 3H1, 2B8, 3C10, 3H9 and 1G5 in IDAS — and ACP-ELISA. The Japanese isolate of WYMV and United States isolates of wheat spindle streak mosaic virus (WSSMV) were detected in IDAS- and ACP-ELISA by ten of the MAbs tested showing that the wheat bymoviruses originating from the three locations share a high epitopic homology. French isolates of barley yellow mosaic virus (BaYMV; pathotypes 1 and 2) were only detected in ACP-ELISA with MAbs 6C3, 3D8, 3H1 and 2B8 whereas the two Japanese strains (I-1, II-1) of MaYMV were recognized with these and also with that of 3C10. In IDAS-ELISA, the two Japanese strains were clearly detected by MAbs, 6C3, 3D8, 3H1, 1F2, 3C10 and 1G5 and the British and Belgian (pathotype 2) isolates only by that of 6C3. Only the Japanese strain of BaYMV, 1-1 could be detected with MAb 3H9 in this ELISA system.     

Nucleotide Sequence of Citrus Tristeza Virus Seedling Yellows Isolate

The complete nucleotide sequence of a seedling-yellows-inducing isolate NUagA of Citrus tristeza virus (CTV) was determined. It consisted of 19302 nucleotides and contained 12 open reading frames (ORF) organized identically to those of previously sequenced isolates. This genome is the largest among the CTV genome sequenced so far ; it is 6 nucleotides (nt), 76 nt, 43 nt, and 53 nt longer than that of T36 (quick decline, Florida), VT (seedling yellows, Israel), T385 (mild, Spain), and SY568 (stem pitting, California), respectively. Sequence comparison of NUagA and the other isolates revealed approximately 90% identities throughout the 3′ half of the genome. The 5′ half of the genome was only about 70% identical to that of T36 but still high at about 90% to those of VT, SY568, and T385. Comparison of amino acid sequences on ORF1a encoding polyproteins, the most variable region, reflects the CTV isolate relationship ; NUagA is closely related to VT, SY568, and T385, but distantly related to T36. Received 29 May 2000/ Accepted in revised form 16 November 2000