黄瓜花叶病毒猖獗与气候变暖关系及其对策

黄瓜花叶病毒（ＣＭＶ）可经６０多种蚜虫传播,侵染１０００多种植物,近１５年来其危害日渐严重,目前已成为我国发生最普遍、危害最严重的植物病毒。从生物学角度分析了黄瓜花叶病毒的发生猖獗与气候变暖的关系,并提出了依靠农业措施和生物防治手段进行病害控制的对策。     

植物病毒复制酶基因介导的抗病性研究进展（综述）

用编码病毒复制酶的基因转化植物能赋予植物对病毒的高度抗病性。利用病毒的复制酶基因已经成功地获得对烟草花叶病毒（ＴＭＶ）、黄瓜花叶病毒（ＣＭＶ）、马铃薯Ｘ病毒（ＰＶＸ）、马铃薯Ｙ病毒（ＰＶＹ）等具有高度抗病性的转基因植物。复制酶基因在ＲＮＡ水平或者蛋白质水平上的表达，干扰了复制酶的正常功能，进而有效地抑制了病毒的复制，从而达到抗病的目的。     

TMV、PVM和CMV干扰载体构建及对人参果遗传转化

人参果是以营养器官繁殖为主的多年生草本植物,连年种植易造成多种病毒病积累。为了寻求一种能同时抵御多种病毒病的方法,本试验以危害人参果的3种主要病毒为研究对象,根据GenBank中烟草花叶病毒(TMV)P126基因、马铃薯M病毒(PVM)CP基因和黄瓜花叶病毒(CMV)2b蛋白基因序列,利用E-RNAi网站提供的分析软件,筛选出含有较多有效小干扰RNA[siRNA,19 nt]的长dsRNA(Long dsRNA)片段作为RNAi的靶序列。用重叠延伸PCR方法将三个靶标片段融合在一起,构建了一种具有内含子(intro)的反向重复结构和嵌合基因的植物RNAi表达载体pCEIHFR。将pCEIHFR通过冻融法导入农杆菌LBA4404并转化人参果,经过草甘膦筛选和PCR检测,确认其中的24株为转基因阳性植株。     

黄瓜花叶病毒赤豆分离物外壳蛋白基因序列分析及原核表达

根据已报道的黄瓜共上壳蛋白基因序列合成引物,经ＲＴ－ＰＣＲ扩增并克隆了我国黄瓜花叶病毒赤豆分离物的外壳蛋白基因,序列分析表明,外壳蛋白基因全长６５７个核苷酸,编码２１８个氨基酸,其核苷酸序列与黄瓜花叶病毒亚组１的分离物有极高的同源性。     

无公害黄瓜病虫害可持续综合治理措施

目前，黄瓜生产上的病虫害防治仍以化学防治为主，农药施用量大，用药次数、采收次数多，常有今天打药明天上市的现象。加之部分菜农滥用农药，造成瓜条中农药残留严重超标，农药在瓜条上不易完全分解，消费者食用中毒事件屡有发生，直接危害人身健康。因此，在黄瓜生产上应用无公害病虫综合防治技术，可有效地控制各种病虫害的传播蔓延，控制危害。     

侵染上海番茄的黄瓜花叶病毒及其卫星RNA的~(32)P分子标记杂交检测及分子鉴定

2004和2005年夏季,在上海郊区露天栽培的番茄地出现典型的病毒病危害,并造成严重的产量损失。分别以32P标记的CMV基因组RNA3部分序列和卫星RNA的cDNA探针对自然感病的番茄叶组织和提纯的病毒粒子中提取的总RNA进行杂交检测,确定以上植物组织和病毒粒子中均具有CMV及卫星RNA。dsRNA分析确定自然感病叶组织中具有典型黄瓜花叶病毒(CMV)基因及其卫星RNA条带。以常规引物对感病植物的总RNA进行RT-PCR扩增,获得CMV RNA3全长克隆,经测序显示该RNA3序列属于CMV亚组Ⅱ;通过在卫星dsRNA两端分别加上15nt的单链DNA接头,以接头互补序列为引物进行扩增获得一个383nt的卫星RNA的全长序列。同源性分析结果显示其与已报道的CMV卫星RNA同源性为72.6%~99.5%,但其3′末端存在多个碱基的突变。根据同位素杂交检测及分子鉴定,CMV及其卫星RNA变异类型在上海自然感病番茄上发生和普遍存在,可能对病害流行和新的症状出现产生影响。     

温室黄瓜病虫害化学防治现状及其无公害防治对策

简析了温室黄瓜病虫害发生危害及化学防治现状与存在的问题,并提出提高黄瓜植株矿质营养水平、生态调控、黄瓜套袋、科学施用化学农药等病虫害综合防治措施。     

无公害黄瓜嫁接栽培技术

黄瓜嫁接栽培就是利用南瓜等抗土传病害的葫芦科植物作砧木，以黄瓜作接穗，利用嫁接苗进行栽培。目前我国应用最广且效果较好的主要有靠接法和顶插法两种，大多数农民采用靠接法。     

黄瓜嫁接栽培技术

保护地黄瓜栽培由于连作、施肥等原因。导致枯萎病日趋严重,难以控制。枯萎病是一种土传病害,病菌从根部侵染在导管中危害,一般化学药剂很难防治,已成为黄瓜栽培的主要障碍。但这种病害在南瓜上很少发生,应利用南瓜抗枯萎病这一特点,以南瓜作砧木,黄瓜作接穗进行苗期嫁接,不但可以控制枯萎病的危害,且能增强根系吸收力,促进植株生长旺盛,抗逆性增强,产量提高。     

三种主要黄瓜病毒抗性基因的定位

以黄瓜(Cucumis sativus L.)欧洲八号×秋棚为亲本构建的重组自交系(RIL)群体为材料,以病情指数为指标,对群体和亲本进行了小西葫芦(Cucurbitapepo L.)黄化花叶病毒(Zucchini yellow mosaic virus,ZYMV)、番木瓜环斑病毒西瓜株系(Papaya ringspot virus watermelon strain,PRSV-W)和西瓜花叶病毒(Watermelon mosaic virus,WMV)的抗病性鉴定.结果表明3种病毒的病情指数在黄瓜RIL群体呈双峰分布,表明对ZYMV、PRSV-W和WMV的抗性是受主基因控制的性状.利用Joinmap软件进行连锁分析,发现ZYMV和PRSV-W与WMV连锁,3个抗病基因的排列顺序和遗传距离是WMV-6cM-ZYMV-7cM-PRSV-W.根据AFLP、SSR和RAPD标记结果构建了一个黄瓜遗传图谱,3个抗病毒病基因被定位于第二连锁群.     

Resistance in Cucurbita pepo and Cucurbita maxima germplasms to cucumber mosaic virus

Summary A total of 384 Cucurbita pepo and Cucurbita maxima accessions were evaluated in growth chambers or glasshouse tests for resistance to cucumber mosaic virus (CMV). Seedlings were mechanically inoculated at the cotyledon stage, and scored for symptoms on cotyledons and true leaves 7 and 18 days after inoculation. Significant variation in resistance was found. A limited number of accessions were free of visual symptoms of infection. One C. pepo accession and thirteen C. maxima accessions showed a high level of resistance. Generally, C. maxima may be considered more resistant to CMV compared to C. pepo. There is no close relationship between origin, fruit morphotypes and CMV resistance in either species. Some accessions (e.g., C. pepo PI 438699; C. maxima PI 176530, PI 265555, PI 368564, PI 500483) could be useful for the future breeding programmes. The C. pepo cvs. Cinderella and Defender F1, previously described as resistant, showed maximum susceptibility to the yellow strain of CMV.Abbreviations CMV cucumber mosaic virus - WMV watermelon mosaic virus - ZYMV zucchini yellow mosaic virus - CYVV clover yellow vein virus - ZYFV zucchini yellow fleck virus     

我国南方甘蔗病毒种类初步鉴定

依据G enB ank中已报道的甘蔗主要病毒基因组序列设计PCR引物,以采自我国广东、广西、云南、海南等地的甘蔗叶组织总RNA或总DNA抽提物为模板,采用一步法RT-PCR及PCR扩增,对预期扩增产物克隆、测序,根据序列同一性判断测定样品是否含有预期病毒,结果表明,我国南方甘蔗已受到甘蔗花叶病毒(Sugarcane m osa ic v irus,SCM V)、高粱花叶病毒(Sorghum m osa ic v irus,S rM V)、甘蔗黄叶病毒(Sugarcane ye llow leaf v irus,SCYLV)及甘蔗杆状病毒(Sugarcane B ac illiform V irus,SCBV)的侵染,未发现甘蔗线条花叶病毒(Sugarcane streak m osa ic v irus,SCSM V)及甘蔗线条病毒(Sugarcane streak v irus,SSV)。     

人参果主要病毒检测方法研究

为了给人参果病毒检验及抗病性研究提供支持,对人参果采用ELISA和RT-PCR两种检测方法对8份田间材料中的马铃薯M病毒(PVM)、番茄花叶病毒(ToMV)和烟草花叶病毒(TMV)进行检测,对比筛选病毒检测方法。结果表明,ELISA法检测PVM的阳性检出率为87.5%;ToMV为37.5%,疑似率为12.5%;TMV为37.5%。通过RT-PCR检测体系,从人参果样品中分别扩增出与试验设计大小相符的特异条带,PVM阳性检出率为100%,ToMV为 50.0%,TMV为37.5%,检测灵敏性和准确性更高,检测结果符合率在87.5%以上。对扩增阳性产物进行凝胶回收测序,确定为目标条带。     

玉米矮花叶病研究进展

玉米矮花叶病（maize dwarf mosaic virus,MDMV）是世界上玉米产区普遍发生的病毒病害之一。白20世纪90年代以来,我国玉米矮花叶病发生严重,山西、甘肃、山东、河北以及北京等省市先后大流行,造成了巨大的农业经济损失。在我国玉米产区造成危害的主要是该病毒的B株系,主要借蚜虫传播和种子传播;在玉米矮花叶病的防治中,种植抗病品种,并辅以合理的栽培管理,可有效防止MDMV。本文主要综述玉米矮花叶病病毒的理化特性、玉米矮花叶病的发生危害、病原及其传播方式、发病条件、流行与防治、品种（自交系）抗性、抗性鉴定、抗性遗传及其抗病基因工程研究等方面的研究进展,以期为以后玉米矮花叶病的有效防治提供一定的参考。     

番茄不孕病毒BJ株系基因组测定与侵染性克隆

番茄不孕病毒(Tomato aspermy virus,TAV)可侵染包括藜科(Chenopodiaceae)、茄科(Solanaceae)等在内的24个双子叶家族和3个单子叶家族的100多种植物,是具有重要经济价值的植物病毒之一.为研究TAV BJ株系(Tomato aspermy virus,TAV-BJ)的基因组功能,本实验对TAV-BJ基因组克隆测序,并构建侵染性克隆.以TAV-BJ侵染心叶烟(ic otiana glutinosa)的总RNA为模板,RT-PCR获得其RNA2和RNA3;以TAV-BJ的dsRNA为模板,RT-PCR获得全长RNA1,目的片段PCR产物克隆测序获得TAV-BJ基因组全序列信息.RNA1全长3 409 nt,编码994个氨基酸的1a蛋白;RNA2全长3 023 nt,含2个开放阅读框(open reading frame,ORF),2a ORF编码829个氨基酸的2a蛋白,2b ORF编码78个氨基酸的2b蛋白;RNA3全长为2 216 nt,包含2个ORF,3a ORF编码247个氨基酸的3a蛋白,外壳蛋白(coat protein,CP)ORF 编码219个氨基酸的CP蛋白(TAV-BJ基因组RNA1、2和3 GenBank登录号分别为HQ424163,HQ424164和HQ424165).TAV-BJ基因组cDNA克隆体外转录成RNA并接种于心叶烟上,结果表明转录产物在寄主上的症状反应和TAV-BJ病毒粒子RNA的接种相一致,TAV-BJ基因组cDNA侵染性克隆具有活性.由TAV-BJ各个基因片段与缺失2b基因的黄瓜花叶病毒Fny株系(Cucumber mosaic virus,CMV-Fny△2b)构建的假重组病毒接种于心叶烟,结果显示TAV-BJ的RNA2和RNA3能恢复CMV-Fny△2b在寄主上症状反应.嵌合型RNA3F3aTcp和RNA3T3aFcp的症状反应结果表明,F1F2△2bRNA3 T3aFcp在寄主上产生花叶症状与F1 F2△2bT3相一致.本研究获得TAV-BJ的基因组序列,成功构建侵染性克隆,同时发现TAV-BJ的3a基因具有CMV-Fny的2b基因的某些功能.     

Synthesis and antiviral activity of novel chiral cyanoacrylate derivatives

2-Cyanoacrylate is an important kind of herbicide targeted in photosystem II. Starting from cyano ethyl acetate, the chiral title compounds were synthesized under microwave irradiation, which has the advantages of shorter reaction time, higher yield, and simpler procedure. A half-leaf method was used to determine the inhibition and curative efficacies of the eight chiral products against tobacco mosaic virus in vivo. It was found that chiral compound IIc-R possesses moderate inhibition and curative effect in vivo with rates of 89.1 and 43.1%, respectively. In the MTT test, these new chiral compounds were found to possess weak antiproliferation activities to PC3 and A431 cells.     

Properties of land mosaics: Implications for nature conservation in agricultural environments

Agricultural landscapes are mosaics of different land uses. Their vast extent throughout the world means that they have a key role in the conservation of biodiversity. To provide a sound basis for management, it is important to recognise the emergent properties of land mosaics and understand how they influence components of biodiversity. In most studies in agricultural landscapes, inference is restricted to single sites or patches because this is the unit used for sampling and analysis. For mosaic-level inference, sampling must encompass multiple land uses and elements within a mosaic, be aggregated to represent the ‘whole’ mosaic, and be replicated across multiple mosaics. This paper reviews studies in which land mosaics are the unit of replication, to identify the influence on biota of three categories of emergent properties of mosaic structure: the extent of habitat, composition of the mosaic and spatial configuration of elements. The extent of habitat is usually a dominant influence on the occurrence of single species or the richness of assemblages defined by habitat type (e.g., forest birds). The composition of the mosaic, based on the proportions of elements present, strongly influences the species composition of faunal assemblages. Heterogeneity or diversity of elements is often positively correlated with the richness of taxonomic assemblages. In studies that separate the independent effects of emergent properties, spatial configuration generally exerts less influence on biota than extent or composition. A fourth property, the geographic position or environmental variation among land mosaics, also significantly affects the status of the fauna in many studies. Temporal persistence of species and turnover in assemblages in agricultural landscapes are also influenced by the structure of the land mosaic, but there are few long-term data sets that allow comparison of temporal changes with mosaic properties. There is great scope for further investigation of the properties of mosaics and the mechanisms by which they affect the conservation of biodiversity. This includes studies of responses from a wider range of biota (in addition to birds), investigation of spatial scale effects on faunal responses, temporal responses of the fauna to change in mosaic structure (and potential time-lags in response), and the effects of variation in mosaic structure on population demography and ecological processes.     

TMV和PVY外壳蛋白双基因融合干涉及烟草转化

为了降低烟草花叶病毒（tobacco mosaic virus,TMV）和马铃薯Y病毒（potato irus Y,PVY）复合侵染对烟草带来的危害,本实验找到TMV—CP和PVY—CP基因部分保守序列,将保守序列进行双基因融合,此双基因即为RNAi的靶序列,用限制性内切酶将双基因从pMD18-T载体上切下,正反向连接到pUCCRNAi载体后,经酶切鉴定后定向连接到含超强启动子的pC2300—35S—OCS表达载体上,利用冻融法将此表达载体导入只含辅助质粒的根癌农杆菌中,构建含靶序列反向重复结构的RNAi双元载体系统,提取转化质粒,经酶切验证鉴定表明TMV和PVY外壳蛋白基因植物表达双元载体构建成功。并转化烟草,获得了3株对TMV和PVY抗性显著提高的转基因烟草。     

Epidemiology of fungally-transmitted viruses

Abstract. The recent spread of sugar-beet rhizomania and barley yellow mosaic virus in Europe has stimulated fresh interest in plant viruses with soil-borne fungal vectors. Although there are at least 20 such viruses, most of which cause diseases of important field crops, there are many gaps in our knowledge of their epidemiology because much research has concentrated exclusively on the viruses. The vectors are lower fungi that are obligate parasites of plant roots and are therefore difficult to study experimentally. Resting spores containing virus can survive indefinitely in soils but effects of rotation have not been greatly studied. There is no quantitative information relating inoculum levels of fungus and virus to disease development. Only limited information is available about inoculum distribution in soil and factors affecting its potency. The diseases are mostly dispersed by soil movement during agricultural operations but some features of disease distribution in infested fields await adequate explanation. Little is known about interactions with other micro-organisms.     

Effect of adjacent agricultural habitat on the distribution of passerines in natural grasslands

Habitat heterogeneity has often been acknowledged as a key factor determining which species occur in a landscape, but we still know little on the nature and relative importance of the processes controlling species distribution and abundance within complex landscape mosaics. We used a framework defined by the compensation, supplementation and complementation models to study the distribution of four species of passerines typical of steppe habitats and identify the degree to which landscape context accounts for their distribution in the steppe-agriculture mosaic of the Crau, southern France. Steppe habitat was the best predictor of species distribution in all cases and that densities were highest in steppe. One of these species, the Calandra lark, is strictly tied to the natural steppe habitats independently of its context. For another species, the Tawny pipit, we document a significant positive effect of the presence, near steppe habitat, of extensive pastoral habitats, such as fallows and grazed crops. Finally, the abundance of the two remaining species, Skylark and Short-toed lark, was negatively affected by the presence of non-herbaceous habitats in the vicinity of steppe habitat. This suggests that the quality of the steppe habitat, as perceived by these species is conditional to the nature of adjacent habitats. Our results suggest that the management of the context in which steppe habitat is imbedded will significantly affect the distribution and abundance of this group of passerines and determine both habitat quality and conservation value at a landscape scale.