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1.
Studies on lettuce mosaic virus resistance in commercial lettuce cultivars   总被引：5，自引：5，他引：0  
The response to infection with lettuce mosaic virus (LMV) of 16 lettuce cultivars, known to possess the Momo gene for resistance to LMV, was studied in field trials over a 2-year period. Some cultivars developed negligible mosaic symptoms following virus inoculation and had a low virus content as measured by ELISA, while others had more severe symptoms and a higher virus content. Resistant cultivars differed significantly in the effect of LMV upon yield and the correlation between cultivar rankings for yield depression and symptom severity was low.  相似文献   

2.
Ten commercial stocks of rhubarb cv. Timperley Early were found to be infected with turnip mosaic, arabis mosaic and to a lesser extent cherry leaf roll, strawberry latent ringspot and cucumber mosaic viruses. Significant yield differences were recorded between the stocks in forcing experiments, but these were not related to virus incidence. The performance of a mixture of these infected commercial stocks was compared with that of virus-tested stocks in canning, early green-pulled, and forcing experiments. A significant yield advantage was recorded in the first 2 years from the virus-tested stock harvested for canning, but not in the other two experiments. Of the five viruses isolated, turnip mosaic most frequently reinfected virus-tested stocks and there appeared to be a connection between reinfection of the healthy plants and subsequent reduction in their yield.  相似文献   

3.
Cauliflower (Brassica oleracea var. botrytis subvar. cauliflora) is susceptible to wilt caused by Verticillium dahliae but broccoli (B. oleracea var. italica subvar. cyamosa) is not. Infection of broccoli and cauliflower by a green fluorescent protein-expressing isolate of V. dahliae was examined using epifluorescence and confocal laser-scanning microscopy to follow infection and colonization in relation to plant phenology. Plant glucosinolate, phenolic, and lignin contents were also assayed at 0, 4, 14, and 28 days postinoculation. V. dahliae consistently infected and colonized the vascular tissues of all cauliflower plants regardless of age at inoculation, with the pathogen ultimately appearing in the developing seed; however, colonization decreased with plant age. In broccoli, V. dahliae infected and colonized root and stem xylem tissues of plants inoculated at 1, 2, or 3 weeks postemergence. However, V. dahliae colonized only the root xylem and the epidermal and cortical tissues of broccoli plants inoculated at 4, 5, and 6 weeks postemergence. The frequency of reisolation of V. dahliae from the stems (4 to 22%) and roots (10 to 40%) of mature broccoli plants was lower than for cauliflower stems (25 to 64%) and roots (31 to 71%). The mean level of aliphatic glucosinolates in broccoli roots was 6.18 times higher than in the shoots and did not vary with age, whereas it was 3.65 times higher in cauliflower shoots than in the roots and there was a proportional increase with age. Indole glucosinolate content was identical in both cauliflower and broccoli, and both indole and aromatic glucosinolates did not vary with plant age in either crop. Qualitative differences in characterized glucosinolates were observed between broccoli and cauliflower but no differences were observed between inoculated and noninoculated plants for either broccoli or cauliflower. However, the phenolic and lignin contents were significantly higher in broccoli following inoculation than in noninoculated broccoli or inoculated cauliflower plants. The increased resistance of broccoli to V. dahliae infection was related to the increase in phenolic and lignin contents. Significant differential accumulation of glucosinolates associated with plant phenology may also contribute to the resistant and susceptible reactions of broccoli and cauliflower, respectively, against V. dahliae.  相似文献   

4.
Associations among Hop latent virus (HpLV), Hop mosaic virus (HpMV), and Apple mosaic virus (ApMV) were assessed in five hop cultivars at four commercial hop-growing regions in Victoria and Tasmania, Australia. The presence or absence of each virus was confirmed by double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Spatial patterns of virus-infected plants were characterized using the Spatial Analysis by Distance IndicEs ( sadie ) system of pattern analysis. The association among viruses (occurrence and covariation) was assessed using the Jaccard similarity index, Spearman's rank correlation coefficient, and sadie . The spatial pattern of plants infected by HpLV and HpMV ranged from random to highly aggregated depending upon the cultivar infected and the mean disease incidence. The spatial pattern of plants infected by ApMV was aggregated in six of the seven plots where ApMV was present. A strong positive association between HpLV and HpMV was found in all cultivars at all locations. This association may be the result of the viruses sharing a common aphid vector species, the presence of one virus enhancing the ability of the aphid vector to acquire the other virus either through transencapsidation or influences on virus titre, or mixed infections within source plants. Significant associations, positive or negative, were found less frequently between HpLV and ApMV, and HpMV and ApMV.  相似文献   

5.
 感染芜菁花叶型病毒和烟草花叶型病毒的油菜病株种子的种皮内带有病毒,种胚自未成熟到成熟始终不带病毒。
烟草花叶型病毒在种皮内的存活期限长于芜菁花叶型病毒。烟草花叶型毒株61-16号,在"胜利"油菜病株种子的种皮内可以存活26个月以上;芜菁花叶型病毒存活期最长的一个毒株不超过25个月,最短的不到4个月。  相似文献   

6.
Tamada T  Uchino H  Kusume T  Saito M 《Phytopathology》1999,89(11):1000-1006
ABSTRACT Two mutant strains of beet necrotic yellow vein virus (BNYVV) containing deletions in RNA 3 were obtained by single lesion transfers in Tetragonia expansa. The deleted regions encode either 94 or 121 amino acids toward the C-terminal part of the 25-kDa protein (P25). Wild-type and mutant virus strains were inoculated by Polymyxa betae to sugar beet seedlings of susceptible and partially resistant cultivars. No differences were found in virus content in rootlets between mutant and wild-type viruses or between susceptible and resistant cultivars after culture for 4 weeks in a growth cabinet. However, when virus-inoculated seedlings were grown in the field for 5 months, the wild-type virus caused typical rhizomania root symptoms (69 to 96% yield loss) in susceptible cultivars, but no symptoms (23% loss) developed in most plants of the resistant cultivar, and BNYVV concentrations in the roots were 10 to 20x lower in these plants than in susceptible plants. In contrast, the mutant strains caused no symptoms in susceptible or resistant cultivars, and the virus content of roots was much lower in both cultivars than in wild-type virus infections. Wild-type RNA 3 was not detectable in most of the taproots of a resistant cultivar without any symptoms, suggesting that replication of undeleted RNA 3 was inhibited. These results indicate that the P25 of BNYVV RNA 3 is essential for the development of rhizomania symptoms in susceptible cultivars and suggest that it may fail to facilitate virus translocation from rootlets to taproots in the partially resistant cultivar.  相似文献   

7.
侵染蚕豆的芜菁花叶病毒的鉴定与提纯   总被引：1，自引：0，他引：1  
 在江苏浙江等地的蚕豆苗上出现的红褐色环斑或白色斑驳症状.经鉴定是芜菁花叶病毒侵害的结果.在病组织中的病毒粒体为弯杆状.长度750-800nm。摩擦接种在苋色藜上,接种叶上出现大块黄色枯斑,直径约3毫米,顶叶系统感染,在克氏烟、芜菁、油菜上为系统花叶.在蚕豆苗上的症状,视品种和环境条件而异,在有限生长的品种上多为红褐色环斑.在启东蚕豆上多为白色斑驳,豆荚上也可出现变色斑。对病毒的提纯方法作了改进,用冻融的20%蔗糖溶液可代替常规的10-40%蔗糖梯度液,精提纯的效果相同。  相似文献   

8.
About 90 barley cultivars mostly of European or Japanese origin, were grown for 2–5 years at eight sites in China where barley yellow mosaic virus was known to occur. The sites were selected because they had previously been used to screen breeding lines and some differences between them in cultivar response had been suspected. ELISA tests showed that symptomless plants were not infected by the virus and the proportions of plants with symptoms were therefore recorded as a measure of susceptibility. European cultivars carrying the ym4 gene, which confers resistance to the common European strain, were usually resistant at two sites but susceptible at the others, but one (cv. Energy) was resistant at all sites. Eleven of the Japanese cultivars showed differential responses between sites but there was no correspondence with strains recognized in Japan. There are probably several distinct Chinese strains but further experiments would be needed to identify them. The Japanese cultivars Chosen, Hagane Mugi, Iwate Mensury 2 and Mokusekko 3 seem to be resistant to all known virus strains and are probably the most useful for plant breeders.  相似文献   

9.
 从表现花叶症状的德国进口番红花上获得一线状病毒分离物SA,线状病毒粒子长度为700~800nm。其在人工接种的11科39种植物中能侵染6科14种植物,在克里芙兰烟上产生系统坏死,在小白菜、花椰菜等十字花科植物上产生系统花叶或为隐症,在昆诺藜等藜科植物上为局部侵染。在番红花病叶、球茎及克里芙兰烟病叶组织中观察到卷轴状和片层状聚集的风轮状内含体。免疫吸附和免疫修饰电镜观察结果显示,SA与芜菁花叶病毒((TuMV)具有紧密的血清学关系。根据这些特征将SA鉴定为TuMV的一个分离物。这是TuMV侵染番红花的首次报道。  相似文献   

10.
 西瓜花叶病毒(watermelon mosaic virus,WMV)是危害我国葫芦科作物生产的重要病原。培育和种植抗病品种是防治病毒病最经济有效的措施。本研究利用RT-PCR和血清学方法在表现环斑症状的西葫芦果实上检测到WMV,未检测到番木瓜环斑病毒(papaya ringspot virus,PRSV)。接种WMV侵染性克隆到西葫芦品种绿源冬宝,果实表面产生环斑症状,表明WMV是引起西葫芦果实表面环斑症状的重要病原。利用间接ELISA方法对山东泰安的西瓜、黄瓜、甜瓜、西葫芦和南瓜等46个样品检测发现33个样品表现WMV血清学阳性(检出率71.74%),薛庄采集的带有环斑症状的西葫芦均检测到WMV。对山东省81份葫芦科作物种质资源抗WMV鉴定发现西葫芦品种万盛丰宝、盛丰金珠表现中抗(MR);西瓜品种绿宝新秀和浪潮一号表现中抗(MR);甜瓜品种黄皮面瓜表现抗病(R);黄瓜品种星君贝贝表现中抗(MR);南瓜品种爱维80南瓜表现高抗(HR),蜜本南瓜、传统蜜本南瓜、七叶早南瓜、玲珑二号和绿贝贝迷你南瓜等5个品种表现抗病(R);瓠瓜品种均表现为感病(S)。研究结果对合理布局葫芦科作物品种防控WMV具有重要意义。  相似文献   

11.
Many pollen grains from Chenopodium quinoa plants infected with sowhane mosaic sobemovirus (SMV) were collapsed, grooved and had sunken opercula, whereas those from the first flowers of virus-free plants were smooth, rounded and with protuberant opercula. However, pollen grains from later flowers of virus-free plants were similar in appearance to those from the virus-infected plants. Similar but less obvious symptoms were found in pollen of Plantago lanccoiata infected with either ribgrass mosaic tobamovirus or broad bean wilt virus. No symptoms were found in pollen of Hordeum vulgare cv. clipper, H. sponiaitcum or Triticum acstivum infected with barley suripe mosaic hordeivirus, nor in pollen of a Cardaminc sp. naturally infected with a strain of turnip yellow mosaic tymovirus. The symptoms, even those shown by pollen from SMV-infected C quinoa, seemed not to be sufficiently characteristic for diagnosis of virus infection.  相似文献   

12.
As Pepino mosaic virus has become a pathogen of major importance in worldwide tomato production, information is needed on possible differences between the sensitivity of cultivars towards infection. Furthermore, it is important what hosts other than Solanaceae may be virus reservoirs and are, therefore, threats for tomato cultivation. Two PepMV isolates (PepMV-Sav, E397, a European tomato isolate and PV-0554, a Peruvian pepino isolate) differing in their origin and virulence were used for several experiments to investigate these issues. The response to mechanical inoculation with PepMV was studied using 25 tomato cultivars, seven indicator plant species, and nine other possible horticultural host plants. Symptom development after infection with PepMV was monitored and the virus was detected by DAS-ELISA and IC-RT-PCR. Garlic and broad bean were shown to be additional hosts of PepMV depending on the virus isolate. Nicotiana benthamiana seems to be the most sensitive indicator among all tested indicator plants developing symptoms. Both PepMV isolates infected all tested tomato cultivars. Development of disease symptoms depended on the cultivar and the virus isolate but symptoms were not visible in all cases. None of the cultivars showed tolerance against the two isolates but two responded with a lower susceptibility at an absorbance level of 0.2 (healthy control 0.09). It was observed that some cultivars grown hydroponically showed also lower losses in biomass and yield. Data indicated a correlation between absorbance level in DAS-ELISA and reduction in total tomato growth.  相似文献   

13.

Canola (Brassica napus L.) oil yield and fatty acid composition are the function of genotype, climate conditions, morphology, and physiology as well as crop management. In this study, the reaction of different canola cultivars—in terms of seed oil content and fatty acids—to different planting dates and foliar zinc application during two experimental years (2016–2017) was investigated in the field in arid and semi-arid regions of Karaj, Iran. The experiment was performed as a factorial split plot in a randomized complete-block design with three replications. Three sowing dates (February 9, 19, 29) and two foliar zinc applications (non-application as control and zinc application; spraying in the stem elongation stage) were factorially randomized to main plots, and canola cultivars (Sarigol, Dalgan, Salsa, and Solar) were allocated to sub-plots. The results indicated that the effect of year, planting date, zinc application, cultivar, and the interaction effect of planting date and cultivar on quality traits (glucosinolate and fatty acids) and seed yield were significant (p?<?0.01). The delay in winter planting of spring canola cultivars caused a significant reduction in seed yield, oil yield, and the content of oleic, linoleic, and palmitic fatty acids and increased the content of linolenic, erucic, stearic, arachidic, and behenic fatty acids and glucosinolate. The highest seed yield (4732.2?kg/ha), oil yield (2066?kg/ha), and oleic acid content (66.52%) were observed in the Dalgan cultivar in the zinc application treatment with normal planting date (February 9). The Salsa cultivar had the highest content of erucic acid (0.46%) and glucosinolate (17.3?μmol/g meal) in the control treatment with the last planting date. Because the quality of edible canola oil depends on the increase in unsaturated fatty acids, particularly oleic and linoleic acids, and the reduction of erucic acid and glucosinolate, planting Dalgan cultivar with zinc application at the normal planting date is recommended for the study area and similar areas.

  相似文献   

14.
C. KERLAN  S. MEVEL 《EPPO Bulletin》1987,17(1):125-130
An antiserum was prepared against cauliflower mosaic virus strain S. The specificity of the reagents (IgG labelled with alkaline phosphatase) allowed the use of ELISA test (standard method) for virus detection, directly from cauliflower plants. Triton and urea had to be added to the homogenizing phosphate buffer. Labelled antibodies from strain S were also reactive - with high optical densities - against strain PV-45 and Cabb-BJI, but a distant relationship appeared with strain CM4-184. Two thousand samples picked in the field were analysed and some results showed that the virus could be latent in the plant. A good correlation was observed between ELISA and biological indexing results. However, the serological diagnosis was more precise when cauliflowers were doubly infected by cauliflower mosaic virus and turnip mosaic virus.  相似文献   

15.
The incidence and severity of three diseases of oilseed rape, caused by beet western yellows luteovirus (BWYV), cauliflower mosaic caulimovirus (CaMV) and turnip mosaic potyvirus (TuMV), were assessed in England and Wales in the springs of 1992 and 1993. In 1992, 62% of oilseed rape crops examined were found to contain BWYV, with an average of 28% plants infected; 14% of crops contained CaMV, with an average of 5% plants infected; and TuMV with 3% crops and < 1% plants infected. In 1993, BWYV was found in 42% of crops and 12% of plants infected; CaMV in 25% of crops and 7% of plants infected; and TuMV in 14% of crops and 5% plants infected. The yields of plants showing severe virus symptoms were reduced by an estimated 70 to 79%. The high incidence of CaMV and TuMV in oilseed rape crops could have important consequences for rapeseed production in the UK and also serve as a source of virus for vegetable brassicae.  相似文献   

16.
Isolate DX of potato virus X (PVX) caused the typical reactions of a group three strain, systemic top necrosis in presence of potato hypersensitivity gene Nx and mosaic with gene Nb. When tubers harvested from DX-infected plants of the Nx: Nb cultivars Maris Piper and Pentland Dell were, grown on, most progeny plants were healthy, but some had systemic top necrosis caused by DX while others had mosaic symptoms in upper leaves and severe necrosis in lower ones. Infective sap from the plants with mosaic and necrosis always caused similar symptoms when inoculated to Pentland Dell. Only group four PVX strains can cause systemic infection without top necrosis in Nx:Nb cultivars, so the affected plants all contained a group four strain. That the severe necrosis of their lower leaves resulted from a shock reaction rather than from isolate DX also being present was indicated because the plants partially recovered, inoculations from near to the dilution end-point failed to demonstrate any separation of strains and behaviour on back-testing to Pentland Dell was unchanged after passage twice through tubers of this cultivar. Also, although DX caused severe necrotic symptoms in tubers of both Nx: Nb cultivars, these symptoms did not develop in tubers of plants with mosaic and necrosis. When cultured serially in Nicotiana glutinosa , the group four strain eventually reverted to group three.  相似文献   

17.
Differentiation of pathotypes of lettuce mosaic virus   总被引：2，自引：0，他引：2  
Differential interactions between six crisphead cultivars of lettuce and five isolates of lettuce mosaic virus (LMV) have identified a novel resistance factor in the cultivar Ithaca. The LMV isolates could be grouped into three pathotypes, two of which have not been identified previously. One of these, pathotype III represented by an isolate from Spain, was virulent on all of the cultivars. There were differences in aggressiveness between isolates of the same pathotype.  相似文献   

18.
W. HUTH 《EPPO Bulletin》1989,19(3):547-553
During the last ten years yellow mosaic of barley has been spreading more and more in European countries and in some infested areas yield loss can only be prevented by growing resistant cultivars. Breeding of such cultivars is one of the most important goals of small-grain breeders. To select resistant cultivars, several methods are available such as mechanical inoculation, growing of plants in infested soil in the field or in growth chambers as well as using root powder of infected plants. The situation has recently been complicated by the discovery that yellow mosaic is caused by at least two distinct but closely related viruses (barley yellow mosaic virus and barley mild mosaic virus). Inoculation methods are not equally effective for these two viruses. Although it appeared initially that resistance to the two viruses was linked, there are now indications that some barley cultivars respond differently, and there may even be a third virus involved. Programmes for selection of resistant cultivars now have to take account of this.  相似文献   

19.
The multiplication of Soil-borne wheat mosaic virus (SBWMV) was studied in mixtures of two winter wheat (Triticum aestivum) cultivars, one susceptible (Soissons) and the other resistant (Trémie). Two seed mixtures of susceptible and resistant varieties in ratios of 1 : 1 and 1 : 3 and their component pure stands, i.e. each variety grown separately, were grown in a field infected with SBWMV. The presence of the virus was detected using DAS-ELISA from January to May. The resistant cultivar Trémie showed no foliar symptoms nor could the virus be detected in the leaves or roots. In May, about 88% of plants of susceptible cultivar Soissons grown in pure stands were infected. At this time, the disease reduction relative to pure stands was 32.2% in the 1 : 1 mixture and 39.8% in the 1 : 3 mixture. Optical density (OD) values from ELISA of the infected plants in the two mixtures were consistently lower than that of the infected plants in cultivar Soissons in pure stands. The ELISA index (EI) calculated using three scales of OD values was 65.5% in the susceptible cultivar in pure stands. The value for this index was 19.1% in the 1 : 1 mixture and 7.9% in the 1 : 3 mixture. The plants of the resistant cultivar Trémie infected in the same field and transferred in January to a growth cabinet at 15 °C multiplied the virus and produced viruliferous zoospores. These results show that the resistant cultivar Trémie plays a role in disease reduction in the cultivar mixtures in field conditions. Possible reasons for this are discussed.  相似文献   

20.
The hypothesis that enhancing the level of glucosinolates in leaves of oilseed rape would increase resistance to two fungal pathogens was tested. Thirty-three Brassica napus lines with variable leaf glucosinolate contents were assessed for susceptibility to infection by Leptosphaeria maculans and Alternaria spp. under field conditions. The data clearly showed that there was not a simple positive relation between glucosinolate content and resistance, and that the hypothesis can be refuted. The level of Alternaria infection of both leaves and pods was positively correlated with glucosinolate content, while for L. maculans there was no significant relationship between the two variables. It is suggested that these pathogens have become specialists on glucosinolate-containing taxa in an analogous way to insect herbivores.  相似文献   

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