花生丛枝病原的电子显微镜研究

花生丛枝病普遍发生于海南岛花生种植区,在崖县、儋县大田中更为常见,俗称“花生公”。这种病害,国内过去认为是一种病毒病,     

花生丛枝病原的电子显微镜研究

花生丛枝病普遍发生于海南岛花生种植区,在崖县、儋县大田中更为常见,俗称“花生公”。这种病害,国内过去认为是一种病毒病,但无正式的研究与报道。在国外,对花生丛枝病也仅推测是由类菌原体(MLO)引起的病     

几种常见花生病毒血清学关系的研究

花生是世界上重要的经济作物,中国也是个花生消费大国,但是常有8种重要的花生病毒危害,包括花生斑驳病毒(PMV)、花生条纹病毒(PStV)、花生丛簇病毒(GRV)、花生丛矮病毒(PCV)、蕃茄斑萎病毒(TSWV)、花生芽枯病毒(BNN)、花生矮化病毒(PSV)和黄瓜花叶病毒(CMV).70年代以来在全国各地多次爆发花生病毒病,并引起大面积减产,经济损失巨大,因而花生病毒的检测和转基因花生抗毒株的选育变得尤为重要[1～3].本研究应用免疫双扩散和酶联免疫法(ELISA)对几种花生病毒的血清学关系进行了研究.     

几种常见花生病毒血清学关系的研究

花生是世界上重要的经济作物,中国也是个花生消费大国,但是常有8种重要的花生病毒危害,包括花生斑驳病毒（PMV）、花生条纹病毒（PStV）、花生丛簇病毒（GRV）、花生丛矮病毒（PCV）、著茄斑萎病毒（TSWV）、花生芽枯病毒（BNN）、花生矮化病毒（PSV）和黄瓜花叶病毒（CMV）。70年代以来在全国各地多次爆发花生病毒病,并引起大面积减产,经济损失巨大,因而花生病毒的检测和转基因花生抗毒株的选育变得尤为重要［‘－’］。本研究应用免疫双扩散和酶联免疫法（ELISA）Z4几种花生病毒的血清学关系进行了研究。三材料与方法…     

环斑猛猎蝽对草地贪夜蛾低龄幼虫的捕食功能分析

为探究环斑猛猎蝽Sphedanolestes impressicollis Stal对草地贪夜蛾Spodoptera frugiperda Smith的捕食潜能,在室内条件下研究了环斑猛猎蝽4龄若虫对草地贪夜蛾1~3龄幼虫的捕食功能、搜寻效应以及环斑猛猎蝽自身密度对捕食草地贪夜蛾的干扰作用。结果表明：环斑猛猎蝽4龄若虫对草地贪夜蛾低龄幼虫的捕食功能反应符合Holling II模型。环斑猛猎蝽4龄若虫对草地贪夜蛾1龄、2龄、3龄幼虫的瞬时攻击率分别为0.900、1.229和1.259,处理时间分别为0.018 d、0.050 d和0.205 d,日最大捕食量分别为55.897头、19.853头和4.871头。环斑猛猎蝽4龄若虫的搜寻效应与草地贪夜蛾密度呈负相关。环斑猛猎蝽4龄若虫对草地贪夜蛾低龄幼虫的捕食作用率随自身密度的增加而降低。在捕食草地贪夜蛾1龄幼虫时,环斑猛猎蝽4龄若虫自身密度对其捕食能力干扰最大。研究结果表明环斑猛猎蝽4龄若虫对草地贪夜蛾低龄幼虫有一定的捕食能力,为其田间应用释放技术提供了理论依据。     

广东省雷北农作区鼠类的分布

广东省雷州半岛北部栽培作物地区(包括遂溪县、湛江市郊及海康县的北部、廉江县的东南部等广大地区),土地平坦,起伏轻微,是粤西地区经济作物主要产区之一;盛产甘蔗、花生、蕃薯、芝麻及豆类,接近河沟两岸还种植水稻、席草。这些地区的农作物常受鼠害。为了查明这些地区农业害鼠情况,笔者于1964年6月至1965年7月间,选择有代表性地区,进行了重点调查。现将调查资料整理出来,希望对当地农田鼠害防除,提供一些资料。     

脱毒甘薯与未脱毒甘薯的形态识别

甘薯病毒是一种常年发生的系统性病害。由于甘薯是无性繁殖作物,一旦感染了病毒,其体内的病毒会不断积累,使病情逐年加重,最终导致甘薯品种种性退化,产量和品质同步下降,大面积生产上,常年一般团甘薯病毒病减产叨叽以上。甘薯病毒种类复杂,已报道的有10多种,我国主要有羽状斑驳病毒和甘薯潜隐病毒。病株表现为花叶、皱缩、黄化,老叶出现紫红色羽状斑驳或环斑,块根表皮粗糙,皮色变浅,出现龟裂。由于甘薯病毒种类多,传播途径多种多样,且与细胞质共存于细胞中,不同于一般真菌或细菌引起的病害,目前尚无法采用杀菌剂抗生素等药…     

棉铃虫为害花生

1959年在山东烟台专区的莱阳、 海阳、蓬莱等县发现棉铃虫为害花生, 第一天检查受害率仅有10％左右,第二天发展到37％,第三天即达100％。有的地块平均有幼虫两头。田间很难找到完整的嫩叶,使花生的生长发育受到了严重的影响。 棉铃虫为害花生的特点是:初龄幼虫啃食叶肉,以后各龄则从叶缘取食或将嫩叶咬穿。幼虫特别喜欢吃花。为害盛期,每天开的花全被吃掉。 我们用5％DDT粉剂每亩3～5斤喷粉和25％的     

番茄曲叶病及其血清学和PCR测定

我国曾报道的番茄病毒病有多种,其中最常见的是黄瓜花叶病毒(CMV)和烟草花叶病毒(TMV)引起的花叶病。柯冲等(1964)在大陆首次报道烟粉虱(Bemisia tabaci)传播的番茄病毒病——番茄黄顶病,此病在50～60年代曾在广州市郊流行,造成大面积减产。Green等(1984)报道台湾发生番茄黄曲叶病,此病与日本的番茄黄矮病(Tomato yellow dwarf)相似,并且与烟草曲叶病毒(TLCV)有血清学关系。印度、委内瑞拉等国也曾报道发生由烟粉虱传播的番茄曲叶病和番茄黄曲叶病。1991和1992年秋,在广西南宁市郊发现一种症状表现为植株矮缩,叶片向上向内卷曲,叶背面产生耳状或杯状增生物,对光看有时可见叶脉呈墨绿色,不结果或少结果的番茄病害。1992年秋广西农业科学院的番茄试验地发病率高达6.8％,对当地秋番茄生产构成了威胁。作者对病害症状、传播、血清学反应及PCR分析等方面与烟草曲叶病毒进行了比较研究,证实了该病的病原与烟草曲叶病毒有很高的同源性。现将研究结果简报如下。     

高效杀线虫剂——二溴氯丙烷

二溴氯丙烷简称DBCP。唐山市轻化工研究所和我厂于1966年先后试制成功80％二溴氯丙烷乳剂。并由我厂正式投产。 几年来,我厂与山东省花生研究所合作,在栖霞、蓬莱等县几十个试验点,对花生根结线虫进行防治,效果显著。     

Apple mosaic virus isolated from hop plants in Japan

A strain of apple mosaic virus was isolated from hop plants in Japan. The virus was purified from young hop plants and back-inoculated to virus-free hop plants obtained by meristem tip culture. Inoculated plants developed chlorotic spots, ringspots and a band pattern accompanied by necrosis in the inoculated and systemically infected leaves. Shoot tips of infected plants sometimes became necrotic and these symptoms resembled those of a ring- and band-pattern mosaiclike disease prevalent in hop gardens in Japan. Since apple mosaic virus was recovered from infected plants, it is likely that the virus was the causal agent of this disease. Agar gel double diffusion tests and ELISA showed the hop virus to be serologically closely related to apple mosaic virus (ApMV), and distantly related to prunus necrotic ringspot virus (PNRSV). The virus had a narrow host range, and infected only cucumber of 18 species of Cucurbitaceae, Chenopodiaceae, Leguminosae or Solanaceae inoculated. It produced chlorotic spots on the inoculated cotyledons of cucumber, but no systemic infection. By contrast, ApMV from apple and PNRSV from peach had wide host ranges and infected cucumber plants systemically.     

Identification and detection of Bougainvillea spectabilis chlorotic vein‐banding virus in different bougainvillea cultivars in Taiwan

A new virus disease of bougainvillea occurred in Taiwan and proved to be caused by a Badnavirus, which is similar to the pathogen tentatively named ‘Bougainvillea spectabilis chlorotic vein‐banding virus (BsCVBV)’ in Brazil according to pathological and molecular results. In electron microscopic observations, typical bacilliform virions measuring 130–158 × 27–42 nm were observed in infected bougainvillea tissues. The transmission tests demonstrated that the virus could be easily transmitted among different bougainvillea cultivars by bud grafting but not by mechanical inoculation. BsCVBV showed different pathogenicity to various bougainvillea cultivars in our inoculation tests. The Taipei‐Red and Thimma cultivars showed the apparent foliar symptoms of chlorosis, chlorotic spots, wrinkling and leaf‐distortion; the original species of Bougainvillea glabra produced chlorotic spots and vein clearing on leaves without wrinkling or leaf distortion; both ‘Mrs. Eva Mauve Variegata’ and Hati Gadis showed mild mottling and faint spots of leaves; Helen Johnson was tolerant to BsCVBV. Our devised PCR‐based assays demonstrated that BsCVBV could replicate and persistently survived in all tested bougainvillea cultivars used in this study although it induced different symptoms in them. The BsCVBV‐1 primer pair devised from our cloned BsCVBV‐specific DNA fragments proved to be efficient in the PCR assays for the rapid and specific detection of BsCVBV in Taiwan, and this PCR‐based method is helpful in the quarantine, inspection and ecological studies for BsCVBV in Taiwan.     

A damaging outbreak of arabis mosaic nepovirus in blackcurrant, the occurrence of other nepoviruses in Ribes species, and the demonstration that alfalfa mosaic virus is the cause of interveinal white mosaic in blackcurrant

In a crop of blackcurrant (Ribes nigrum), cv. Baldwin in Eire, chlorotic mottling and ringspot symptoms in leaves on plants and severe crop loss was associated with infection with arabis mosaic nepovirus (ArMV) and the presence in the soil of its nematode vector, Xiphinema diversicaudatum. This is only the second report of ArMV damaging a crop of blackcurrant. Tomato black ring (TBRV) and raspberry ringspot nepoviruses were detected in single plants of redcurrant (R. rubrum) in England and flowering currant (R. sanguineum) in Scotland respectively; each of these infected plants showed foliar chlorotic line-pattern symptoms. This is the first record of TBRV in redcurrant. A single blackcurrant plant in New Zealand showing symptoms typical of those described for interveinal white mosaic disease, contained alfalfa mosaic virus (AMV). When AMV particles were purified and concentrated from herbaceous test plants and mechanically inoculated to young blackcurrant plants, several became infected with AMV and most infected plants developed systemic symptoms typical of the original disease. This provides the strongest evidence to date that AMV is the causal agent of interveinal white mosaic disease.     

First report of occurrence of two viruses on pea field in Iran

An intensive survey was conducted to identify virus diseases affecting pea crops in Tehran province of Iran. A total of 270 pea samples were collected randomly from pea fields. samples were tested by Double Antibody Sandwich Enzyme Linked Immunosorbent Assay (DAS-ELISA) using polyclonal antisera prepared against PSBMV (AS-0129, DSMZ, Braunschweig, Germany) and TSWV (AS-0580, DSMZ, Braunschweig, Germany). Virus disease incidence in pea samples was followed by PSBMV (33%) TSWV (24.4%) and PSBMV+TSWV (17.77). The positive samples with PSBMV were extracted in 0.05M phosphate buffer pH 6.5-7 containing 2% pvp and inoculated on Pisum sativum, Vicia faba, Chenopodium quinoa, Chenopodium amaranticolor. That produced in Pisum sativum; leaflets roll downwards, shoots curl, internodes shorten and plants are rosetted. Early infections reduce flower and fruit formation or eliminate their development. Broad bean has symptoms accompanied by a certain margin rolling and leaflet distortion. In Chenopodium amaranticolor necrotic local lesions and Chenopodium quinoa chlorotic local lesions had produced. The positive samples with TSWV were extracted in 0.01 M phosphate buffer containing 1% Na2 SO3 and inoculated on Petunia hybrida, Pisum sativum. TSWV causes several symptoms in infected peas, including brown leaf petiole and stem coloration, leaflet spotting, vein necrosis. In petunia hybrida after approximately 5 days showed local necrotic lesion. Biological purification in TSWV with chlorotic local lesions in Petunia hybrida and in PSBMV; chlorotic local lesions in Chenopodium quinoa were done. In PSBMV, back inoculated on Pisum sativum and Vicia faba also tested with DAS-ELISA. RT-PCR confirmed the results. This is the first report of PSBMV and TSWV naturally infecting pea in Iran.     

Dipsacus fullonum: an Alternative Host of Sunflower chlorotic mottle virus in Argentina

Dipsacus fullonum L. is a biennial weed that is widely spread in the Pampean region of Argentina. Plants of this species showing leaf mosaic symptoms were collected near sunflower ( Helianthus annuus L.) crops infected with Sunflower chlorotic mottle virus (SuCMoV). Symptomatic plants were tested by biological, serological and molecular assays. Sunflower and Nicotiana occidentalis L. plants mechanically inoculated with extracts from symptomatic D. fullonum leaves developed typical SuCMoV symptoms. Samples were DAS-ELISA positive when probed with a SuCMoV antiserum. RT-PCR was used to amplify the whole coat protein gene of the infecting virus. An 807 bp fragment was amplified, cloned and sequenced. The deduced amino acid sequence (EU606023) shared 96% amino acid identity with the SuCMoV sequence (AF255677). These results indicate that D. fullonum mosaic is caused by an isolate of SuCMoV. Thus, this finding has epidemiological relevance as the weed may act as a natural virus reservoir.     

Влнянне характера эаселення ноля капустноii совкоii(Barathra brassicae L.) эффективноеть трихограммы (Trichogramma evanescens Westw.) (Lepidoptera,Noctuidae; Hymenoptera,Trichogrammatidae)

TSWV belongs to the genus Tospovirus which was established in the family Bunyaviridae, a family of animal viruses. Besides TSWV, Impatiens necrotic spot virus (INSV) and ground nut bud necrosis virus (GBNV) were established as different Tospovirus species. Tospoviruses have quasispherical particles of 85 nm diametre which are surrounded by a membrane and contain 3 RNA species and 4 structural proteins. In Tospovirus infected plant cells virions were detected in cavaties of the endoplasmatic reticulum and additionally amorphous electron dense material accumulates in infected cells. Defective forms of TSWV lack the ability to form complete virus particles. TSWV is the only plant pathogenic virus that is transmitted by thrips which transmit the virus with different efficiency. The virus has an extensive plant host range of more than 360 different species. The developing symptoms depend on the Tospovirus species, the virulence of the virus strains and the environmental conditions.

Based on the reaction of TSWV isolates with N‐specific polyclonal antisera, 3 serogroups were established. The most frequently used technique for serologically based diagnosis of Tospoviruses is DAS ELISA with N‐specific or preadsorbed antisera against complete virus. For TSWV epidemiology distinct weeds and cultural host plants play an important role for the survival of virus and vector. Breeding for resistance is the most important preventive measure of control.     

福建蔗区甘蔗斐济病毒的鉴定

甘蔗斐济病毒(Sugarcane Fiji disease Virus,FDV)最早于1910年由Lyon等在斐济岛和新几内亚等地发现。其后,澳大利亚、马达加斯加、所罗门群岛、印度尼西亚、海布里地群岛、马来西亚、菲律宾以及泰国等的蔗区均有发生。我国各蔗区以前未见报道。但自1981年以来,福建多个蔗区还曾多次反映有疑似甘蔗斐济病病株出现,1982～1984年     

Comparison of some apple latent viruses

Apple latent viruses were eliminated from, the tips of apple shoots by exposure to a temperature of 36 °C for various periods. The length of treatment needed to eliminate a particular virus differed from plant to plant, but viruses were always inactivated in the same order: first chlorotic leaf spot, followed by stem pitting and finally Spy decline. Quince plants developed sooty ring-spot and bark necrosis when inoculated with buds from some heat-treated apple clones infected with Spy decline virus. Only chlorotic leaf spot virus was transmitted to herbaceous hosts by sap extracts from apple leaves, petals and fruits, and returned from herbaceous plants to apple. This virus, isolated from either apple or cherry, caused a dark green mottle on peach leaves.