Reaction of cucurbits species to infection with Zucchini lethal chlorosis virus

Zucchini lethal chlorosis virus (ZLCV) is a tospovirus that infects species of cucurbits in Brazil and is transmitted by the thrips Frankliniella zucchini. The purpose of the present work was to evaluate the reaction of seven species of cucurbits to infection with ZLCV under field and greenhouse conditions in Piracicaba County, SP. In the field experiment, ZLCV infection occurred naturally. In the greenhouse, plants were mechanically inoculated with ZLCV at the cotyledonal stage. Evaluations were based on symptoms expression and detection of the virus by PTA-ELISA. The percentages of infected plants for field and greenhouse assays, respectively, are indicated in parenthesis for each species/cultivar: Cucurbita pepo var. Caserta (72.9 and 70.7); C. maxima var. Alice (16.0 and 10.4); C. maxima var. Exposição (0.0 and 0.0); C. moschata var. Menina Brasileira (29.2 and 18.2); C. maxima × C. moschata hybrid Takaiama (63.4 and 42.7); Citrullus lanatus var. Crimson Sweet (25.0 and 25.0); Cucumis sativus var. Safira (14.3 and 41.2); and C. anguria (21.4 and 22.7).     

番茄斑萎病毒属ssRNA-M序列比对分析

番茄斑萎病毒属(Tospovirus)是布尼亚病毒科唯一的植物病毒属,在热带、亚热带以及温带地区引起许多作物和花卉严重病害的发生.该研究利用DNAstar、DNAman等软件对其RNA-M编码G1G2蛋白和NSm非结构蛋白的核酸和蛋白质序列进行分析,发现Tospovirus属病毒的G1G2蛋白和NSm非结构蛋白序列的长度和GC含量在不同病毒种间变异不大,同时得出序列比对图和一致性(Identity)的值、同源性(Homolog tree)的值和系统进化树(Phylogenetic tree)的值,并发现根据NSm蛋白质序列划分的2个相似性组与前人划分的血清组非常接近.     

广东西瓜上检测到甜瓜黄斑病毒

在广东发现了可能被番茄斑萎病毒属(Tospovirus)病毒侵染的西瓜,采用ELISA和RT-PCR法对该西瓜病样进行了检测,西瓜病叶粗汁液不与番茄斑萎病毒(Tomato spotted wilt virus,TSWV)和西瓜银斑驳病毒(Watermelon silver mottle virus,WSMoV)的血清发生反应;利用引物J13/UHP通过RT-PCR可以扩增出约1400 bp的基因片段,该片段包括一个840 bp的核衣壳蛋白ORF,其推导的氨基酸序列与已报道的Melon yellow spot virus(MYSV)NP基因氨基酸序列的同源率都为99%,进化树分析表明侵染广东西瓜的病毒(命名为MYSV-GZ)属于Tospovirus的MYSV血清组。     

The S RNA segment determines symptom differences on Tetragonia expansa between two Watermelon silver mottle virus isolates

The WS-Y isolate of Watermelon silver mottle virus (WSMoV) causes severe necrosis in Tetragonia expansa. To determine the RNA segment that induces symptoms, genome reassorants between WS-Y and an isolate causing mild mottle, WS-O, were generated. The origin of each segment in the reassortants was identified by RT-PCR and subsequent restriction enzyme analysis of the amplified fragments. Thirty genome reassortants were isolated from co-infected T. expansa plants. The reassortants with the S RNA segment of WS-Y caused severe necrosis, while those with the S RNA segment of WS-O caused a mild mottle; hence, the S RNA determined symptom expression. The incidence of reassortants was disproportional among genotypes. The most frequent genome reassortant possesses the L RNA of WS-Y, the M RNA of WS-O and the S RNA of WS-Y. A similar ratio of genotypes was found in isolates of local lesions on Chenopodium quinoa. These results strongly suggested that competition occurred independently between the individual RNA segments in a co-infected T. expansa plant, not between isolates.     

一种侵染花生的新病毒鉴定初报

从广东省广州市郊花生上分离获得1个新的病毒分离物，病毒粒体为球状，直径约100nm。该病毒分离物在人工接种鉴定的4科13种植物中，能侵染3科11种植物；与花生芽枯病毒(PBNV)抗血清有弱阳性反应；病毒SRNA 3’端813个核苷酸序列与PBNV和西瓜银叶斑驳病毒(WSMoV)同源性为80％左右，与TospovirW属中其它病毒同源性为39％～65％。初步明确该病毒分离物为Tospovirus属的一种新病毒，暂定名为花生坏死斑点病毒(peanut necrotic spot virus，PNSV)。     

Thrips: Pests of Concern to China and the United States

Thrips are among the most important agricultural pests globally because of the damage inflicted by their oviposition, feeding, and ability to transmit plant viruses. Because of their invasiveness, a number of pest species are common to both China and the United States and present significant challenges to growers of a wide range of crops in both countries. Among the pest thfips common to both countries are four of the major global thrips pests, Frankliniella occidentalis (Pergande), Scirtothrips dorsalis Hood, Thrips palmi Karny, and Thrips tabaci Lindeman. This review addresses characteristics that enable thrips to be such damaging pests and how biological attributes of thrips create challenges for their management. Despite these challenges, a number of successful management tactics have been developed for various cropping systems. We discuss some of these tactics that have been developed, including the use of cultural controls, biological controls, and judicious use of insecticides that do not disrupt overall pest management programs. The exchange of this type of information will help to facilitate management of pest thrips, especially in regions where species have recently invaded. A prime example is F. occidentalis, the western flower thrips, which is native to the United States, but has recently invaded China. Therefore, management tactics developed in the United States can be adapted to China. Because further success in management of thrips requires a thorough understanding of thrips ecology, we discuss areas of future research and emphasize the importance of collaboration among different countries to enhance our overall understanding of the biology and ecology of thrips and to improve management programs for these widespread pests.     

侵染水鬼蕉和花朱顶红的番茄斑萎病毒属病毒的电镜和DAS-ELISA诊断

从昆明市郊区采集到呈同心圆褪绿环斑、褐色枯斑症状的水鬼蕉[Hymenocallis littoraris（Jacq.）Salisb.]和花朱顶红[Hippeastrum vittatum（L’Hér.）Herb.]植株,采用电子显微镜技术和DAS-ELISA进行检测,在水鬼蕉和花朱顶红病叶分离物SGJ-KM和ZDH-K...     

从云南蝴蝶兰上检测到番茄斑萎病毒属病毒

 应用电镜观察、DAS-ELISA以及RT-PCR检测,从症状表现黄化、环斑的云南蝴蝶兰(Phalaenopsis amabilis)病样中分离得到的一个病毒分离物Tospo-Pha。该分离物粒子近球形、具包膜、直径约90nm,与番茄斑萎病毒属(Tospovirus)的西瓜银色斑驳病毒(Watermelon silver mosaic virus,WSMoV)/花生芽坏死病毒(Groundnut bud necrosis virus,GBNV)复合抗血清呈强阳性反应,分子检测发现该分离物SRNA5'末端序列与CaCV大岩桐分离物(CaCV-Gloxinia)同源性最高(91.0%),在系统进化树中与CaCV聚于同一分支。上述结果表明,从云南蝴蝶兰中分离到的Tospo-Pha属于Tospovirus病毒。     

An effective system for detecting Iris yellow spot virus transmission by Thrips tabaci

A simple, effective and convenient laboratory leaf system was developed to detect transmission of Iris yellow spot virus (IYSV) by thrips. It was shown that IYSV was transmitted highly efficiently by adults and also by larvae of five thelytokous populations of Thripstabaci from distinct areas in Japan: over all these populations, transmission efficiency of adults ranged from 20·4% (19/93) to 41·1% (76/185) and that of larvae from 17·3% (14/81) to 44·1% (67/152). Finally, it was demonstrated that IYSV infection was not detrimental to the development and fecundity of thrips until early adulthood. Larval mortalities of virus‐exposed thrips were higher than in their unexposed counterparts in all three populations, but the differences were not significant. The results demonstrated that T. tabaci populations have considerable potential to cause outbreaks of IYSV and spread the disease because of their efficient transmission of the virus.     

西花蓟马传播病毒病的研究进展

西花蓟马［Frankliniella occidentalis (Pergande)］是一种世界性的重要农业害虫,目前在69个国家和地区已有报道。西花蓟马能以持久性的方式传播番茄斑萎病毒属(Tospovirus)的病毒,所传播病毒造成的经济损失远远大于其本身所造成的损失。因此,许多学者对西花蓟马及其传播的番茄斑萎病毒属病毒进行了大量研究。本文主要综述了近年来西花蓟马传播病毒的种类、番茄斑萎病毒属病毒的结构以及西花蓟马的传毒机制等方面的研究进展。