传播植物病毒的介体简述

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     

植物病毒经介体昆虫唾液腺水平传播至寄主韧皮部机制的研究进展及展望

很多植物病毒经介体昆虫以持久循回型的方式水平传播至寄主韧皮部致病，而唾液腺是介体昆虫持久传毒的重要器官，也是植物病毒在介体昆虫内循回需要克服的最后一道防线。持久性植物病毒要完成水平传播，必须突破昆虫唾液腺屏障的阻碍，因此病毒和介体昆虫间形成了“攻”与“守”的较量与对决。揭示持久性植物病毒克服昆虫唾液腺屏障，实现水平传播的机制，对病害控制具有重要意义。该文着眼于介体昆虫唾液腺在持久传毒过程中的重要功能，回顾了虫传植物病毒突破介体昆虫唾液腺侵入屏障和释放屏障的分子机制，探讨了昆虫唾液蛋白通过调节植物或昆虫的适应性和行为促进或抑制病毒水平传播的功能，为制定阻断介体昆虫传播植物病毒途径的防控策略提供理论依据。     

用血清学特异电镜检测种传植物病毒

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     

书刊评介

本书揭示了传病介体获取并向寄主传播病毒等病原因子的机制。内容涉及昆虫学、植物病理学和病毒学,囊括了从蚊子到叶蝉直至线虫等传病介体以及从病毒到枝原体直至原生动物等病原体的相关知识。书中文章还提到了有关新兴的传病介体的生态学以及生命环境与非生命环境对病原物传播的影响;成为展现这一领域的现代思维的论坛,对从事研究和实际防治由传病介体所导致的动植物病害、人类疾病的学生、教师和科研、实际工作者均有重要意义。     

烟草病毒病的防治方法

烟草病毒病害是烟草的主要病害.发病普遍严重,在我国部分烟区造成严重的损失,威胁着烟叶生产的可持续发展,已经成为烟叶优质、高效生产的限制因素.烟草病毒病的种类很多,已报道的有20多种,病原的个体很小,其基本形态为粒体,大部分植物病毒的粒体为球状、杆状和线状,少数为弹状、杆菌状和双联体状等.烟草植物病毒没有主动侵染寄主的能力,自然状态下主要靠介体和非介体传播.病毒的介体生物主要有蚜虫、叶蝉和飞虱,土壤中的线虫和真菌以及杂草等.病毒的非介体传播途径主要是通过机械、有性和无性繁殖材料、嫁接等方式.     

我国植物病毒病介体昆虫研究的进展

自1939年我国开始报道蚜虫传播蚕豆病毒病以来,至今已知虫传植物病毒和类菌原体有68个,引起100多种病害,其中属禾本科作物的近30种;十字花科、葫芦科、豆科和茄科等果菜类作物的病害60多种;果树及木本植物等病害20种。经接种证实的介体昆虫有52种,其中蚜虫22种,飞虱、叶蝉20种,其它10种。 近年来有关植物病毒介体昆虫的文献报道数量显著增加,从全国省级以上农业及生物科技刊物上发表的,与植物病毒和介体昆虫两者均有关的论文,在四十年代以前仅4篇,五十年代为17篇,六十年代74篇,七十年代42篇,1980—1984年增到130多篇。有     

应用昆虫介体细胞单层快速检测水稻矮缩病毒的侵染

水稻病毒,诸如水稻矮缩病毒,(Rice-gall dwarf virus)水稻瘤矮病毒(Ric-egall dwarf virus)和水稻短暂性黄化病毒(Rice transitory virus),已知都由其叶蝉介体传播到奇主植物上,而不能用其它方法进行机械传播。这些病毒的侵染力只能通过人工注射少量病毒悬浮液到介体叶蝉腹腔内进行测定。用这种方法而获得     

蚜虫传播非持久性病毒的取食行为调控机制

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。     

植物寄生线虫体内病毒检测方法研究进展

线虫作为植物病毒重要的传播媒介之一,引起病毒病的传播和蔓延。本文综述了近年来线虫介体体内植物病毒的检测方法,有电子显微镜检测法、血清学检测法、PCR检测法等,以期为我国开展该方面工作提供参考。     

大麦黄条点花叶病毒传播方式和传播特性研究初报

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。     

我国草莓主栽区病毒种类的鉴定

 病毒种类鉴定结果表明我国草莓主要栽培区存在草莓斑驳病毒、草莓轻型黄边病毒、草莓镶脉病毒和草莓皱缩病毒。四种病毒的总侵染株率达80.2%,其中单种病毒侵染株率为41.6%,两种或两种以上病毒复合侵染株率为38.6%。前三种病毒均为球状病毒,粒体直径分别为25-30nm、23nm和50nm;皱缩病毒为杆状病毒,大小为380×70nm。传染性试验的结果证实,草莓病毒可通过嫁接、菟丝子传染,但不能通过机械传染。桃蚜可传染斑驳病毒和轻型黄边病毒,其传毒关系前者为非持久性后者为持久性。田间桃蚜蚜虫口密度高峰期与草莓病毒侵染盛期相吻合。     

The occurrence and distribution of nepoviruses and their associated vector Longidorus and Xiphinema nematodes in Europe and the Mediterranean basin1

Six nepoviruses are transmitted by five Longidorus and three Xiphinema species in Europe. The virus and vector associations are: L. apulus and L. fasciatus with artichoke Italian latent nepovirus, L. attenuatus and L. elongatus with tomato black ring nepovirus, L. elongatus and L. macrosoma with raspberry ringspot nepovirus, X. diversicaudatum with arabis mosaic and strawberry latent ringspot nepoviruses and X. index and X. italiae with grapevine fanleaf nepovirus. The distributions of the viruses and their vectors in Europe and the Mediterranean basin are described. The following points are commented: presence of non-indigenous nematode-transmitted nepoviruses in Europe; occurrence of vector nematodes in European countries in the absence of their associated nepoviruses; the possible vectors of serologically distinct strains of grapevine fanleaf nepovirus.     

Viruses and virus-like pathogens transmitted by zoosporic fungi1

The viruses and virus-like pathogens transmitted by zoosporic fungi are reviewed. The nine furoviruses (and possible members of the group), with labile rod-shaped particles, have nearly all been shown to be transmitted by plasmodiophoromycete vectors. As they have been reviewed extensively elsewhere, they are covered only briefly; important examples are beet necrotic yellow vein furovirus and potato mop-top furovirus. Five viruses with filamentous particles, tentatively recognized as poty viruses, are transmitted by Polymyxa graminis. Within this group, wheat yellow mosaic virus should be considered to include wheat spindle streak mosaic virus, while the M and NM forms of barley yellow mosaic virus, the best known members of the group, should probably be regarded as distinct viruses. Chytrids (especially Olpidium brassicae) transmit a variety of viruses in different groups (e.g. tobacco necrosis necrovirus, lettuce big-vein virus, melon necrotic spot carmovirus, red clover necrotic mosaic dianthovirus). Finally, several diseases caused by uncharacterized pathogens appear to be transmitted by O. brassicae: freesia leaf necrosis, lettuce ring necrosis, pepper yellow vein, watercress chlorotic leaf spot.     

我国草莓斑驳病毒研究鉴定

 作者采集6省13市病样73株。经鉴定带SMoV的67株,占样本的91.78%。采取指示植物小叶嫁接法及蚜虫分离和传播病毒试验,并辅以病毒提纯,人工摩擦接种草本植物,病毒粒子电镜及超薄切片观察等手段加以确证。在辽宁省田间获得一种草莓中瘤钉毛蚜(Chaetosiphon sp.)以及棉蚜和桃蚜均传播本病毒,传播率依次为70%,40%及33%(最高率),系半持久性传播。病毒提纯制荆最大吸收值在260nm处,最小吸收值在240nm处。A260/280=1.21。电镜观测病毒粒子为球形,直径28~30nm,病叶超薄切片观察,在细胞质里有晶状球形颗粒,直径约25nm,排列整齐。以分离物(M-3)提纯制剂为抗原所制备的抗血清与有关病样呈阳性反应。试验证实了国内SMoV的发生和分布。     

Virus transmission by host-specific strains ofOlpidium bornovanus andOlpidium brassicae

Zoospores of 12 isolatesO. bornovanus from geographically diverse sites and representing the three host specific cucurbit strains were tested as vectors for seven viruses using watermelon bait plants and the in vitro acquisition method. All isolates of the cucumber, melon, and squash strains transmitted melon necrotic spot carmovirus (MNSV) and cucumber necrosis tombusvirus (CNV) but none transmitted petunia asteroid mosaic tombusvirus (PAMV) or tobacco necrosis necrovirus (TNV). The isolates varied as vectors of three other carmoviruses: cucumber leaf spot virus (CLSV); cucumber soil borne virus (CSBV); and squash necrosis virus (SqNV). All cucumber isolates transmitted CLSV and SqNV but not CSBV. Some of the melon isolates transmitted CLSV and SqNV but none transmitted CSBV. Two squash isolates transmitted CSBV and SqNV but not CLSV. Two isolates ofO. brassicae transmitted only TNV and a third did not transmit any of the viruses. The species of bait plant sometimes affected transmission. The most efficient vector strains ofO. bornovanus, as determined by reducing zoospores and virus in the inoculum, were the cucumber strain for CLSV; the cucumber strain for CNV if cucumber was the bait plant or melon strain if watermelon was the bait plant; and the squash strain for SqNV. The plurivorous strain ofO. brassicae was the most efficient vector of TNV.Olpidium bornovanus is the first vector reported for CSBV and is confirmed as a vector of SqNV. It is proposed that all carmoviruses may have fungal vectors.Ligniera sp. did not transmit any of the viruses in one attempt.Abbreviations CLSV cucumber leaf spot virus - CNV cucumber necrosis virus - CSBV cucumber soil borne virus - MNSV melon necrotic spot virus - PAMV petunia asteroid mosaic virus - SqNV squash necrosis virus - TNV tobacco necrosis virus - TBSV tomato bushy stunt virus     

Identification and transmission of Piper yellow mottle virus and Cucumber mosaic virus infecting black pepper (Piper nigrum) in Sri Lanka

Sri Lankan black pepper with symptoms of yellow mottle disease contained a mixture of viruses: Piper yellow mottle virus (PYMV) particles (30 × 130 nm), Cucumber mosaic virus (CMV, 30 nm diameter isometric particles), and unidentified, isometric virus-like particles (30 nm diameter). An effective purification procedure is described for PYMV. Immunosorbent and conventional electron microscopy successfully detected badnavirus particles only when at least partially purified extracts were used. PYMV was confirmed as the cause of the disease, with the other two viruses apparently playing no part in producing symptoms. PYMV was transmitted by grafting, by the insect vectors citrus mealy bug ( Planococcus citri ) and black pepper lace bug ( Diconocoris distanti ), but not by mechanical inoculation or through seeds. The CMV isolate was transmitted to indicator plants by mechanical inoculation and by the vector Aphis gossypii , but not by Myzus persicae ; but neither mechanical nor insect transmission of CMV to black pepper was successful. A sensitive polymerase chain reaction assay was developed to detect PYMV in black pepper.     

Virus Transmission Phenotype Is Correlated with Host Adaptation Among Genetically Diverse Populations of the Aphid Schizaphis graminum

ABSTRACT Schizaphis graminum is an important insect pest of several grain crops and an efficient vector of cereal-infecting luteoviruses and poleroviruses. We examined the virus transmission characteristics of several distinct populations and various developmental stages of the aphid. Seven well-characterized S. graminum biotypes maintained at the USDA-ARS laboratory in Stillwater, OK, and two biotypes maintained in New York (one collected in Wisconsin and the other collected in South Carolina) were tested for their ability to transmit five viruses that cause barley yellow dwarf disease (BYD). Four of the Oklahoma biotypes, which do not commonly colonize agronomic crops, and the Wisconsin biotype, were efficient vectors of several viruses. The three other Oklahoma biotypes, which do colonize agronomic crops, and the South Carolina biotype, were poor vectors of all five viruses. Thus, the vector specificity long associated with viruses causing BYD is not limited to the level of aphid species; it clearly extends to populations within a single species. S. graminum nymphs are reported to be more efficient vectors of Barley yellow dwarf virus (BYDV-SGV) than are adults. This was confirmed only for the Wisconsin biotype, but not for the other eight S. graminum biotypes. Thus, there does not appear to be a generalized developmentally regulated barrier to the transmission of BYDV-SGV in S. graminum. Furthermore, the developmentally regulated vector competency observed in the Wisconsin biotype did not extend to other viruses. BYDV-PAV and Cereal yellow dwarf virus-RPV were transmitted with similar efficiency by all S. graminum biotypes when acquired by nymphs or adults.     

Strawberry virus diseases1

To prevent damage to strawberry from virus diseases one must plant only virus-free stock and grow it under insect-proof conditions. Indexing for virus infection to monitor the introduction and spread of viruses should be carried out at every stage of development of nursery stock. Most strawberry viruses are aphid-transmitted, and some nematode-transmitted. Mottle, crinkle and mild yellow edge are the most economically important diseases, especially in combination. Virus infection causes loss of plant vigour, growth, reduced yield, fruit quality, off-colour of leaves, and reduced leaf size. Virus spread is more rapid during spring and autumn, varying greatly by year and place according to aphid populations and weather.     

A theoretical assessment of the effects of vector-virus transmission mechanism on plant virus disease epidemics

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.