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1.
小麦蓝矮病植原体16S rDNA基因片段的比较分析   总被引:21,自引:3,他引:18  
 小麦蓝矮病是陕西乃至西北冬麦麦区的一个重要病害,由介体条沙叶蝉专化性传播。对小麦蓝矮病株叶片和带毒条沙叶蝉进行超薄切片及电镜观察,在叶片韧皮部和叶蝉后肠中均观察到大量典型植原体。利用植原体16S rDNA基因保守序列通用引物对Rm16F2/Rm16R1,应用PCR技术从小麦蓝矮病株叶片中扩增到1.4 kb的特异片段。通过对16S rDNA基因片段序列同源性比较,结果表明小麦蓝矮病病原与三叶草绿变、翠菊黄化、绣球花绿变、草莓矮化和番茄巨芽植原体亲缘关系较近,其同源率为99.2%~99.9%。据此可以判定小麦蓝矮病植原体是属于植原体16SrⅠ组,确定了其分类地位。  相似文献   

2.
正小麦蓝矮病(Wheat blue dwarf,WBD)是我国西北麦区一种重要植原体病害,在我国西部地区危害严重。该病害由异沙叶蝉(Psammotettix alienus L.)专化性传播,介体传毒成为病害流行的重要中心环节[1]。本实验室前期通过免疫荧光标记研究发现WBD植原体免疫膜蛋白(immunodominant membrane protein, IMP)与介体异沙叶蝉肌动蛋白互作,说明IMP在植原体传播和致病过程中起关键作用。  相似文献   

3.
水稻南方黑条矮缩病发生规律及防控对策初探   总被引:21,自引:3,他引:18  
我国新发生水稻病毒病水稻南方黑条矮缩病由斐济病毒属建议新种南方水稻黑条矮缩病毒(Southern rice black-streaked dwarf virus,SRBSDV,Genus Fijivirus)引起。迁飞性害虫白背飞虱为其传播介体。依据近年田间调查和试验结果分析,白背飞虱不能经卵将病毒传给下一代,后代须在病株上取食才能获毒。若虫最短获毒饲育时间为5~10min,体内循徊期为3~5d。若虫获毒后可终生传毒,最短传毒取食时间为5~10min,且若虫传毒效率高于成虫。白背飞虱带毒率与虫源性质密切相关,采自病株的虫源明显高于采于健株的虫源。因此,对灯下白背飞虱的检测能够反映自然种群的带毒状况,对早期监测和预警具有重要意义。田间发病表现为轻病田病株呈零星分布,重病田病株呈集团分布。水稻各生育期均可感病,感病生育期越早,症状越严重。针对大田的应急防控,应着重做好秧田避害、治虫防病和本田初期病株清除及介体防治,加强病情监测和灯下介体带毒检测。该病害的长期治理,除培育抗性品种、提高预警能力外,降低介体昆虫的种群数量,是控制病毒病流行的根本措施。  相似文献   

4.
灰飞虱对水稻条纹叶枯病的传毒特性初步研究   总被引:5,自引:0,他引:5  
灰飞虱Laodelphax striatellus(Fallen)是水稻条纹叶枯病(Rice stripevirus)的传毒介体。水稻分蘖期前感染病毒后,心叶卷曲而后枯死;拔节期后感病,穗部大多畸形扭曲不实。70年代云南中部地区的富民、姚安、大姚、易门、禄丰、永胜、昆明等县市都曾发生,部分地区整片枯死甚而成灾。1982年从易门县秧田分别捕获越冬代成虫和第一代若虫带回本所室内进行传毒特性研究,结果表明:在平均气温19.6℃条件下,水稻条纹叶枯病毒在灰飞虱体内的循回期平均为12.7天,终身带毒,能连续传毒或间歇传毒。健稻喂饲带毒虫30分钟即能染病,以秧苗2—3叶期最易感染。雌虫自然带毒率和获毒率分别比雄虫高出33.3%及55.6%。  相似文献   

5.
灰飞虱传毒特性研究初报   总被引:2,自引:0,他引:2  
灰飞虱是水稻条纹叶枯病(RSV)的传毒介体,不论长翅型或短翅型成虫都能带毒,并能传毒发病,但以雌虫所占比例较高。各龄若虫也都能带毒,并传毒发病,龄期愈大,带毒率愈高。不同病区虫源自然带毒率差异较大,重病区的保山(邹里)带毒率最高达61.9%,传毒频次多,传毒发病率达17.8%;轻病区的巍山带毒率为10%,传毒发病率仅0.86%;宜良和姚安则介于两者之间。在平均温度21.6—22.3℃条件下,潜育期平均为19.4—20.3天;在平均温度24.9-25.6℃下,潜育期平均为13.5—14.4天。水稻返青期,分蘖初期、盛期、末期都能传毒发病,拔节、孕穗及灌浆期传毒后未见发病,在保山灰飞虱1年发生六至七代,全代历期除越冬代(第七代)长达131.4天外一至六代为34.3—68.4天;卵历期除第一代为21.6天外,二至七代为7.9—12.8天;若虫历期除越冬代(第七代)为71.6天外,一至六代为13.1—26.2天;成虫历期除越冬代达50天外,一至六代为6.4—25.8天。一般雌虫比雄虫寿命长。  相似文献   

6.
利用双重RT-PCR和DIBA快速检测法,对近年广西南方水稻黑条矮缩病传毒介体白背飞虱带毒率进行监测,结果表明:2010~2012年白背飞虱平均带毒率分别为8.18%、0.93%和4.41%,早春白背飞虱带毒率较低,随着外地虫源不断迁入及本地虫源积累、繁殖,后期白背飞虱带毒率明显上升。前期白背飞虱带毒率监测预警,对指导南方水稻黑条矮缩病科学防控意义重大。  相似文献   

7.
小麦蓝矮植原体寄主范围的鉴定及RFLP分析   总被引:6,自引:0,他引:6  
 小麦蓝矮是我国首次报道的小麦植原体病害。采用介体接种植物,症状观察和应用植原体16S rDNA基因通用引物对R16mF2/R16mR1进行PCR扩增,在接种小麦和传毒介体中均扩增出1.4kb的特异片段,鉴定出小麦蓝矮植原体新寄主7种。用巢式PCR方法对小麦蓝矮病田自然发病杂草进行分子检测,从表现症状的10种杂草中均扩增出1.2kb的特异片段。利用6种植原体特异性限制性内切酶对10种杂草的扩增片段进行RFLP(restriction fragment length polymor-phism)分析表明:扩增片段的RFLP图谱与目前已知的16Sr I组翠菊黄化植原体的RFLP图谱相近。鉴定出小麦蓝矮植原体田间自然新寄主10种。  相似文献   

8.
研究了一种人工培养液对各种常见的昆虫(主要是叶蝉)的亲和性和适用性.结果表明,该人工培养液适于本试验中大多数昆虫的人工饲养.用此方法,悬钩子广头叶蝉Macropsis.ftscula Zetterstedt和桤树广头叶蝉Oncopsis alniSchrank分别被再次确认为悬钩子矮化植原体和桤树黄化植原体的传播介体;田旋花麦蜡蝉Hyalesthes obsoletus Signoret再次被确认为葡萄黄化(stolbur)植原体的传播介体.此前,上述三种叶蝉已被传统的人工接种方法鉴定为相应植原体的传播介体.危害桤树的河谷树叶蝉Allygus modestus Scott尽管虫体DNA检测结果经常为阳性,但迄今其人工培养液的检测结果都是阴性,因此,我们认为河谷树叶蝉不是桤树黄化植原体的传播介体.Eppendorf管人工培养液饲养法不仅适用于潜在的植原体介体昆虫的筛选鉴定,而且可用于介体昆虫的生物防治研究.此外,本研究首次发现自然感染了葡萄上的一种被德国人称为"Vergi-lungskrankheit"植原体(AY组)的草地脊冠叶蝉Aprodes makarovi Zachvatkin.  相似文献   

9.
大麦黄条点花叶病毒(Barley yellow striate mosaic virus,BYSMV)是我国小麦产区新发现的一种病毒,为了明确该病毒的发生流行规律并建立相应的防治方法,在温室条件下对该病毒的传播方式、介体传毒特性进行了研究。初步研究结果表明:BYSMV仅由介体昆虫灰飞虱(Laodelphax striatellus Fallén)传播,不能通过机械摩擦、土壤和病残体传播。该病毒在灰飞虱体内的循回期最短为6 d,接种后20 d达到传毒发病盛期。灰飞虱最短获毒和传毒时间均为1 min,病毒在小麦苗中的最短潜育期为5 d。由此可见,灰飞虱对BYSMV具有较强的获毒和传毒能力。本研究为下一步进行该病毒的寄主范围、病害的发生规律等方面的研究提供了技术手段,也为生产上预防和控治由该病毒引起的病害提供了理论依据。  相似文献   

10.
杜真真  刘艳  王锡锋 《植物保护》2020,46(3):175-179
异沙叶蝉可传播小麦矮缩病毒Wheat dwarf virus(WDV)和小麦黄条纹病毒Wheat yellow striate virus(WYSV)两种病毒。本文根据WDV和WYSV的基因序列分别设计两种病毒的特异性引物对,以含有上述两种病毒的异沙叶蝉样品总RNA为模板,以随机引物为3′端通用引物反转录获得cDNA,然后在同一个PCR反应体系加入两对引物,分别得到与预期相符的773 bp和322 bp扩增产物条带。通过对引物浓度、dNTP和rTaq用量以及退火温度等条件进行优化,建立了能在同一异沙叶蝉体内检测WDV与WYSV两种小麦病毒的双重RT-PCR方法。该双重PCR方法特异性强、敏感性高,可以快速准确地在一个体系里同步检测介体昆虫体内的两种病毒,有效地检测虫体内病毒带毒率,这些结果可为病毒预测预报和病害防治提供参考。  相似文献   

11.
Wang S  Gererich RC 《Phytopathology》1998,88(9):885-889
ABSTRACT An indirect immunofluorescent technique was developed to localize tobacco ringspot nepovirus (TRSV) in the vector nematode Xiphinema americanum sensu stricto. A population of this nematode that efficiently transmitted TRSV was given an acquisition access period of 10 days on TRSV-infected cucumber. Treatment of fragments of viruliferous nematodes with a polyclonal antiserum against TRSV followed by fluorescein isothiocyanate-conjugated goat anti-rabbit immunoglobulin G resulted in virus-specific bright fluorescence only in the lumen of the stylet extension and esophagus. Virus-specific fluorescent signals were observed in the virus-retention region of 44% of the nematode fragments examined. The percentage of nematodes labeled with virus-specific fluorescence increased as the acquisition access period increased from 0 to 22 days; the increase paralleled the increase in the transmission efficiency of the nematode population. Visualization of the entire virus-retention region of individual nematodes within a population of vector or nonvector nematodes provides a rapid and simple means of monitoring specific attachment of plant viruses.  相似文献   

12.
The study of the transmission biology of insect-borne plant viruses is important to develop disease control practices. We characterized the transmission of a nanovirus, Banana bunchy top virus (BBTV), by its aphid vector Pentalonia nigronervosa Coquerel (Hemiptera, Aphididae) with respect to temperature, vector life stage, and plant access time. Adult aphids transmitted BBTV more efficiently than third instar nymphs at all temperatures tested. Adult aphids transmitted the virus more efficiently at 25 and 30 degrees C than at 20 degrees C, but temperature had no impact on transmission efficiency by nymphs. By decoupling the relationship between temperature and aphid BBTV acquisition or inoculation, we determined that temperature affected inoculation events more strongly than acquisition. Longer plant access periods increased viral acquisition and inoculation efficiencies in a range of 60 min to 24 h. Both BBTV acquisition and inoculation efficiencies peaked after 18 h of plant access period. We also show that BBTV transmission by P. nigronervosa requires a latent period. Our results demonstrate that vector transmission of BBTV is affected by temperature, vector life stage, and plant access period.  相似文献   

13.
Basic studies carried out in India showed that the incubation period of TLCV in plants varied from 8 days in August to 90 days in winter. The acquisition threshold for the whitefly,Bemisia tabaci Gen., was 31 min; it resulted in 3% transmission. An acquisition access of 24 h for a female whitefly on a TLCV source resulted in 30% transmission. A minimum feeding period of 32 min was required by a viruliferous whitefly to cause infection on tomato test plants; this gave 4% transmission. With inoculation access of 24 h on tomato test plants, the transmission rose to 24%. Starving the vector for 1 h pre-acquisition or 1 h pre-inoculation resulted in higher levels of transmission of TLCV: 36 and 40%, respectively, compared with 20% for non-starved whiteflies. Extending the fasting period beyond 1 h resulted in a reduced transmission level. The whiteflies could acquire the virus from the cotyledonary leaves of an infected tomato plant, with a resultant 28% transmission; but infection did not occur when the whiteflies had an inoculation access to such leaves. Higher transmission rates were obtained when the younger leaves on tomato plants were used for acquisition and inoculation. Transmission was 8 and 38% when five whiteflies per plant were allowed 24 h of acquisition access to 11- and 2-month-old virus sources, respectively. After an acquisition access of 24 h to a TLCV source, male and female whiteflies retained their infectivity for 5 and 53 days, respectively. Nymphs can acquire and transmit the virus. When ten whiteflies of each sex were given 24 h of acquisition and of inoculation access, the subsequent transmission rate of males and females was 56 and 86%, respectively. This virus is not transovarially transmitted. Whitefly colonies raised on brinjal were more efficient (70 and 84% transmission in two experiments) than those raised on chilli, cotton, cowpea, tobacco or tomato.  相似文献   

14.
B型烟粉虱近20年来入侵许多国家和地区,已成为重要的世界性作物害虫,其主要危害方式之一是传播双生病毒,造成作物病毒病大发生.应用PCR技术,研究了入侵我国的B型烟粉虱个体获取、存留及传播烟草曲茎病毒(Tobacco curly shoot virus,TbCSV)的能力.B型烟粉虱在感染TbCSV的普通烟毒株上饲毒30 min时,就可在40%的个体内检测到TbCSV DNA,个体带毒率随饲毒时间延长而增加,饲毒12 h后,带毒率达100%;TbCSV DNA在B型烟粉虱体内可存留10天左右,但不能终身存留;传毒处理植株的发病症状及PCR检测结果表明,B型烟粉虱是TbCSV的传播媒介.  相似文献   

15.
The vector competence of Frankliniella occidentalis for Chrysanthemum stem necrosis virus (CSNV) was evaluated. Three vector strains with distinct competences for Tomato spotted wilt virus (TSWV) transmission were investigated, including an artificially selected strain (TsH) that has a particularly high competence (>90 %). Newly hatched larvae of F. occidentalis were given an acquisition access period of 5 days on CSNV-infected D. stramonium leaves, and reared to maturity. Their transmission efficiencies were examined using a leaf disk assay using Petunia x hybrida leaves. Following the leaf disk assay, the virus accumulation in the vectors was examined via a double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) of their bodies. The results showed that the CSNV acquisition and transmission efficiency of the TsH strain did not differ from those of the others, indicating that the competence of F. occidentalis as a vector for CSNV is not related to that for TSWV. The CSNV transmission and acquisition efficiencies of two F. intonsa strains (Hiroshima and Fukuoka) were also evaluated. In Hiroshima strain, 35 % of adults were viruliferous, but only two transmitters (3 %) were observed. In Fukuoka strain, 6 % were viruliferous, and no transmitters were observed. These results indicate that F. intonsa cannot be a major vector for CSNV. The accumulation of CSNV in the adults of F. occidentalis and F. intonsa evaluated using DAS-ELISA showed a significant difference in ELISA values among transmitter, viruliferous non-transmitter, and non-viruliferous individuals. These results clearly demonstrated that only transmitters that accumulated a threshold quantity of virus can transmit CSNV to plants.  相似文献   

16.
为明确南方水稻黑条矮缩病毒(Southern rice black-streaked dwarf virus,SRBSDV)编码的非结构蛋白P5-1参于SRBSDV在介体白背飞虱体内侵染过程中的作用机制,通过原核表达蛋白制备SRBSDV编码的非结构蛋白P5-1的多克隆抗体,并应用Western blot和免疫荧光标记法检测抗体的特异性,以注射法将来源于P5-1基因的dsRNA(ds P5-1)注入获毒1 d的白背飞虱体内,5 d后通过免疫荧光标记法检测ds P5-1对SRBSDV在白背飞虱体内增殖的影响,同时以注射来源于GFP基因的dsRNA(ds GFP)为对照。结果显示,Western blot和免疫荧光标记分别检测到SRBSDV侵染水稻和白背飞虱表达的P5-1蛋白,表明所制备的P5-1抗体具有特异性。ds GFP处理的对照组白背飞虱带毒率高达81%,而ds P5-1处理的白背飞虱带毒率仅为21%,且P5-1蛋白的表达和SRBSDV在昆虫体内的增殖均受到抑制。表明P5-1蛋白是病毒在昆虫体内增殖的关键因子,可作为阻断病毒在昆虫体内增殖的理想靶标。  相似文献   

17.
 小麦丛矮病毒对传毒介体灰飞虱的有害影响,表现在:使带毒若虫历期延长5.3天,羽化前死亡率比无毒虫高一倍以上,并有3.3%的不羽化个体;使雌虫产卵前期延长1.4和3.5天,产卵天数少8.2和11天,寿命缩短6.5和15.4天,日平均产卵量少1.9粒,每头雌虫平均产卵量少95.4和107.7粒。病毒对子代无影响。
获得丛矮病毒的介体表现抗御低温能力差,如在田间、不加温的温室越冬,长期在0~-4℃及-16~19℃、-21~-24℃各3小时的低温处理,带毒虫死亡率比无毒虫高25~35%。对湿度敏感,在RH 50% 24小时后带毒虫死亡率比无毒虫高10%。耐饥五天,春天带毒若虫死亡率比无毒虫高20%,夏天带毒成虫死亡率比无毒虫高25%,而雄虫耐饥力又比雌虫要差。  相似文献   

18.
DNA of tomato yellow leaf curl virus (TYLCV), a geminivirus transmitted by the whitefly Bemisia tabaci, was amplified from squashes of infected tomato plants and of viruliferous vectors using the polymerase chain reaction (PCR). Samples of infected tissues as small as 1 mm2 were squashed onto a nylon membrane. A 1 × 2 mm strip containing the squash was introduced into a 25 µl PCR reaction mix. The reaction products were subjected to gel electrophoresis, blotted and hybridized with a radiolabeled virus-specific DNA probe. TYLCV DNA was amplified from squashes of leaves, roots, and stem of infected tomato and from individual viruliferous whiteflies. The same squash could be used several times to amplify different virus DNA fragments with various sets of primers. Thus plant and insect squashes can be used as templates for the amplification of geminiviral DNA with no need to prepare tissue extracts or purify nucleic acids. The squash-PCR procedure was applied to study whitefly transmission of TYLCV. Tomato plants were inoculated by placing a single viruliferous insect in the center of a young leaflet. In some plants TYLCV DNA was detected at the site of inoculation as early as 5 min after the beginning of the access feeding and in all plants after 30 min. The squash-PCR procedure also was applied to the study of TYLCV acquisition by the insect vector. TYLCV DNA was detected in the head of whiteflies as early as 5 min after the beginning of the access feeding on infected tomato plants. Viral DNA was detected in the thorax after 10 min and in the abdomen after 25 min.  相似文献   

19.
Rashed A  Nash TD  Paetzold L  Workneh F  Rush CM 《Phytopathology》2012,102(11):1079-1085
ABSTRACT With diseases caused by vector-borne plant pathogens, acquisition and inoculation are two primary stages of the transmission, which can determine vector efficiency in spreading the pathogen. The present study was initiated to quantify acquisition and inoculation successes of 'Candidatus Liberibacter solanacearum', the etiological agent of zebra chip disease of potato, by its psyllid vector, Bactericera cockerelli (Hemiptera: Triozidae). Acquisition success was evaluated in relation to feeding site on the host plant as well as the acquisition access period. Inoculation success was evaluated in relation to vector number (1 and 4) on the plants. Acquisition success was influenced by the feeding site on the plant. The highest acquisition success occurred when insects had access to the whole plant. The results of the inoculation study indicated that the rate of successfully inoculated plants increased with the vector number. Plants inoculated with multiple psyllids had higher bacterial titer at the point of inoculation. Although disease incubation period was significantly shorter in plants inoculated with multiple psyllids, this effect was heterogeneous across experimental blocks, and was independent of pathogen quantity detected in the leaflets 3 days postinoculation. Disease progress was not affected by bacterial quantity injected or psyllid numbers.  相似文献   

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