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1.
传播植物病毒的介体简述 总被引：1，自引：0，他引：1
植物病毒主要靠接触、种子、和介体三种途径传播,其中介体传播最为重要。传毒介体除昆虫、螨类外,还有所谓“土传”中的线虫和低等真菌。菟丝子也可算是“植物介体”,但从它桥接过程看仍脱离不了接触传播范畴。这些介体中,昆虫是最主要的。 介体的传毒特性还常分为三种类型。1.非持久性传播。其特点是只需数秒钟的采食便可获得病毒,病毒只机械地沾附在口器表面,不进入介体体内,所以不存在在介体内潜育的问题,只需几秒钟便能完成传毒过程;若得不到传毒机会,病毒在数小时内就会自然死亡,脱皮也能失去病毒。饲毒前禁食 相似文献
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近年来植物病毒病频发,严重制约着农作物的产量与品质。绝大多数植物病毒依赖媒介昆虫进行传播,而传播的关键是病毒如何突破昆虫的肠屏障、唾液腺屏障和卵屏障等多个生物屏障。植物病毒一方面利用其外壳蛋白或非结构蛋白突破媒介昆虫的中肠屏障和唾液腺屏障;另一方面则与昆虫体内卵黄原蛋白、共生菌以及精子表面蛋白发生特异性互作,促进病毒跨越卵障碍,最终实现病毒在昆虫体内复制。此外,植物病毒还能通过侵染寄主植物影响其防御性状,间接改变媒介昆虫生理及其行为反应,促进病毒在植物间的传播。该研究对植物病毒突破昆虫生物屏障的分子机制,以及植物病毒-植物-媒介昆虫互作对于病毒传播的影响进行了综述,并对阻断病毒传播的方法进行展望。 相似文献
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蚜虫能够传播上百种植物病毒,是最重要的农业介体昆虫之一。蚜虫在刺探和取食植物过程中,唾液组分会连同附着在口针中的病毒粒子一同被分泌进入植物内,在调节植物诱导抗性、病毒侵染扩散、介体昆虫行为等过程中均有重要作用。本文围绕蚜虫传播病毒和获取病毒2个关键过程,总结分析了蚜虫独特的刺吸取食行为与传毒效率和获毒效率之间的联系;针对取食活动中关键的唾液蛋白在调控植物免疫抗性、帮助病毒侵染过程中的功能,阐述了蚜虫高效传播非持久病毒的分子基础;针对蚜虫的获毒过程,综述了病毒侵染植物间接调控蚜虫趋向和行为的作用方式。这些研究的开展将为解释蚜虫和病毒协同侵染的分子机制以及有效开展基于蚜虫取食行为调控的病虫害防控新技术提供思路。 相似文献
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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
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对于多数植物病毒而言,其在田间的自然扩散主要依赖昆虫等介体生物,而媒介昆虫的垂直传播是植物病毒长期存在并发生的重要原因。对媒介昆虫垂直传播病毒机制的研究不仅可以为未来开发高效低毒农药奠定基础,更可为植物病毒与昆虫的互作和病毒病的预测预报提供新的视野及角度。媒介昆虫在植物病毒传播过程中的具体作用在近几年被广泛研究。该文综述了近年来植物病毒在昆虫体内垂直传播的研究进展,包括昆虫传播植物病毒的方式、植物病毒在昆虫体内的垂直传播方式以及虫媒病毒垂直传播的可能机制等。在整个垂直传播的过程中,植物病毒的衣壳蛋白、磷蛋白和媒介昆虫唐氏综合症细胞黏附分子、硫酸乙酰肝素糖蛋白、热激蛋白以及卵黄原蛋白,甚至共生菌都有参与。最后,基于媒介昆虫和植物病毒的关系对未来植物病毒病的绿色防控和生物防控进行了展望。 相似文献
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众所周知许多植物病毒能通过感病植物种子传播,已知的种传植物病毒总数逐年增加。Fullton 列举大约有36种病毒通过63种植物传播;Eennett 和 Shepherd 扩大到列举有50种种传病毒;Phatak 列举85种病毒通过一种或多种寄主种子传播。种子传毒可能是病毒在一种作物上由一个生长季传到下一个生长季的最重要的途径,也是病毒接种介体最初的毒源。某种作物种子将病毒带到一个地区,在该地区如有有效的介体,则会进一步 相似文献
9.
高粱病毒病此前未见报道，症状易与高粱炭疽病、大斑病混淆。电子显微镜检测，高粱病毒病由
多种植物病毒复合侵染所致。影响此病的因素有栽培条件、生育期和传毒介体昆虫。提出"以栽培管理为
基础，消灭传毒媒介为重点.辅以药剂防治"的综合防治对策。 相似文献
10.
水稻黑条矮缩病毒在灰飞虱消化系统的侵染和扩散过程 总被引：2，自引：0，他引：2
水稻黑条矮缩病毒 (Rice black streaked dwarf virus, RBSDV) 由介体灰飞虱(Laodelphax striatellus Fallén)以持久增殖型方式传播, 其编码的P9 1蛋白是形成病毒复制和子代病毒粒体装配的场所—病毒原质(viroplasm)的组分之一。为了明确RBSDV在介体昆虫体内的侵染循回过程, 本研究通过原核表达的P9 1蛋白免疫注射兔子制备P9 1抗体, 应用免疫荧光标记技术研究P9 1在饲毒后不同时期的介体灰飞虱体内的定位。共聚焦显微镜观察到饲毒后3 d, P9 1出现在介体中肠的少数上皮细胞内;饲毒后6 d, 在中肠外表的肌肉细胞分布有P9 1;饲毒后10 d, P9 1分布于中肠和后肠表面的肌肉, 同时在唾液腺也能观察到P9 1的存在。结果表明RBSDV在介体灰飞虱体内首先侵染中肠上皮细胞并复制, 随后扩散到中肠表面的肌肉细胞, 并通过环肌和纵肌扩散到中肠和后肠, 最后扩散到唾液腺。本研究首次直观地阐述了RBSDV在灰飞虱消化系统的侵染和扩散过程, 为有效阻断灰飞虱携带并传播病毒奠定基础。 相似文献
11.
ABSTRACT Sexual forms of two genotypes of the aphid Schizaphis graminum, one a vector, the other a nonvector of two viruses that cause barley yellow dwarf disease (Barley yellow dwarf virus [BYDV]-SGV, luteovirus and Cereal yellow dwarf virus-RPV, polerovirus), were mated to generate F1 and F2 populations. Segregation of the transmission phenotype for both viruses in the F1 and F2 populations indicated that the transmission phenotype is under genetic control and that the parents are heterozygous for genes involved in transmission. The ability to transmit both viruses was correlated within the F1 and F2 populations, suggesting that a major gene or linked genes regulate the transmission. However, individual hybrid genotypes differed significantly in their ability to transmit each virus, indicating that in addition to a major gene, minor genes can affect the transmission of each virus independently. Gut and salivary gland associated transmission barriers were identified in the nonvector parent and some progeny, while other progeny possessed only a gut barrier or a salivary gland barrier. Hemolymph factors do not appear to be involved in determining the transmission phenotype. These results provide direct evidence that aphid transmission of luteoviruses is genetically regulated in the insect and that the tissue-specific barriers to virus transmission are not genetically linked. 相似文献
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本试验在福建省福州市及广东省侥平县两地进行。1978年以来,在福州市以蕉柑、福桔和新会甜橙病树为毒源树,以柑桔实生健苗为指示植物,进行木虱传试验。结果在329株指示苗中,发病40株,发病率12.2%,潜育期短的半年,长的5年。对照指示苗72株均未见发病。1982~1984年,在饶平县以蕉柑病树为毒源树,以椪柑实生健苗为指示植物,共试验70株,发病33株,发病率47.1%,潜育期短的2个月,长的8个月。对照指示苗9株未见发病。木虱传染病苗的病状与毒源树的病状相同,均表现黄梢和叶片斑驳。获"毒"木虱的唾液腺和脂肪体的超薄切片样本在电镜下均观察到原核细胞微生物(称为类立次克体或类细菌)。唾液腺内的病原体分布在外皮层细胞,内皮层细胞和腺腔内。其菌体的形状大小和膜壁结构等特征均与毒源树及木虱传染病苗的筛管细胞内的相同,木虱获得和传递柑桔黄龙病病原的方式与蚜虫传播病毒中的持久性类型十分相似。 相似文献
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ABSTRACT A continuous-time and deterministic model was used to characterize plant virus disease epidemics in relation to virus transmission mechanism and population dynamics of the insect vectors. The model can be written as a set of linked differential equations for healthy (virus-free), latently infected, infectious, and removed (postinfectious) plant categories, and virus-free, latent, and infective insects, with parameters based on the transmission classes, vector population dynamics, immigration/emigration rates, and virus-plant interactions. The rate of change in diseased plants is a function of the density of infective insects, the number of plants visited per time, and the probability of transmitting the virus per plant visit. The rate of change in infective insects is a function of the density of infectious plants, the number of plants visited per time by an insect, and the probability of acquiring the virus per plant visit. Numerical solutions of the differential equations were used to determine transitional and steady-state levels of disease incidence (d*); d* was also determined directly from the model parameters. Clear differences were found in disease development among the four transmission classes: nonpersistently transmitted (stylet-borne [NP]); semipersistently transmitted (foregut-borne [SP]); circulative, persistently transmitted (CP); and propagative, persistently transmitted (PP), with the highest disease incidence (d) for the SP and CP classes relative to the others, especially at low insect density when there was no insect migration or when the vector status of emigrating insects was the same as that of immigrating ones. The PP and CP viruses were most affected by changes in vector longevity, rates of acquisition, and inoculation of the virus by vectors, whereas the PP viruses were least affected by changes in insect mobility. When vector migration was explicitly considered, results depended on the fraction of infective insects in the immigration pool and the fraction of dying and emigrating vectors replaced by immigrants. The PP and CP viruses were most sensitive to changes in these factors. Based on model parameters, the basic reproductive number (R(0))-number of new infected plants resulting, from an infected plant introduced into a susceptible plant population-was derived for some circumstances and used to determine the steady-state level of disease incidence and an approximate exponential rate of disease increase early in the epidemic. Results can be used to evaluate disease management strategies. 相似文献
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ABSTRACT Spiroplasma citri, a helical, wall-less prokaryote in the class Molli-cutes, is transmitted by the beet leafhopper, Circulifer tenellus. Invasion of leafhopper tissues and cytopathological effects by S. citri were investigated by transmission electron microscopy. All eight cell types of the principle salivary glands, as well as the adjacent muscle cells and the cells of the accessory salivary glands, were colonized by the spiroplas-mas. In both midgut epithelia and salivary gland cells, spiroplasmas usually occurred in membrane-bound cytoplasmic vesicles that often were located near the cell periphery. In several salivary gland cells, spiroplas-mas were also observed within membranous pockets apparently formed by invagination of the plasmalemma beneath intact basal lamina. These observations are consistent with spiroplasma entry into the insect cells by receptor-mediated endocytosis. Cytopathological effects of spiroplasma infection in salivary cells included loss of membrane and basal lamina integrity, presence in some cells of irregular inclusion-like structures containing dense matrices of filamentous material that labeled with anti S. citri antibodies, and apparent disorganization of the endoplasmic reticulum. Compared to the tightly aligned fiber bundles in healthy muscle cells, bundles in spiroplasma-containing muscle cells appeared fragmented and loosely arranged. Such symptoms could contribute to the reduction in longevity and fecundity that has been previously reported for S. citri-infected C. tenellus. 相似文献
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Michael Jeger Ziyang Chen Eleanor Cunningham George Martin Glen Powell 《European journal of plant pathology / European Foundation for Plant Pathology》2012,133(1):3-23
Natural enemies have long been used in biological control programs to mitigate the damage caused by herbivory. Many herbivorous
insect species also act as plant virus vectors, enabling virus transmission from plant to plant and hence disease development
in a plant population. Whilst an intuitive assumption would be to expect a decrease in vector numbers to lead to subsequent
reductions in virus transmission, recent evidence suggests that introduction of natural enemies (parasitoids and predators)
may in some cases increase plant virus transmission while at the same time reducing vector numbers. In this paper we review
the evidence for plant-virus-vector-natural enemy interactions, the signalling mechanisms involved and their implications
for virus transmission, and show how a modelling approach can assist in identifying the key parameters and relationships involved
in determining the disease outcome. A mathematical model linking the population dynamics of a vector-parasitoid system with
virus transmission was used to investigate the effects of virus inoculation and acquisition rates, parasitoid attack rate
and vector aggregation on disease dynamics across a wide range of parameter value combinations. Virus spread was found to
increase with enhanced inoculation, acquisition and parasitoid attack rate but decrease with high levels of vector aggregation. 相似文献
16.
目前,我国正遭受多种外来有害生物的入侵,给我国的农业生产以及生态环境造成了严重影响。其中检疫性植物病毒危害大、隐蔽性强,是重要的外来生物。掌握病毒致病的相关机制是有效防控入侵病毒病害的基础。微小RNA(microRNA,miRNA)以及病毒小干扰RNA(small interfering RNA,siRNA)是植物体内重要的非编码小RNA,在病毒致病过程中扮演着重要角色。病毒在侵染过程中,可以利用植物抗病毒免疫反应产生的siRNA进行致病,同时可以直接或间接干扰miRNA的代谢途径,导致相关症状的产生。本文根据植物小RNA的近期研究进展,对miRNA和病毒siRNA的产生途径、生物学特性以及作用分子机制进行了综述,并对其在病毒侵染过程中的作用进行了探讨,初步从小RNA的角度阐述了植物病毒的致病机制,以期为检疫性病毒病害的防控提供理论基础。 相似文献