密执安棒形杆菌的DNA条形码基因筛选与评价

密执安棒形杆菌是一种重要的植物病原细菌,其包含了能引起不同植物病害的5个亚种。近年来迅速发展起的DNA条形码技术给植物病原细菌快速准确的检测鉴定提供了新思路,本文对棒形杆菌属的4条候选DNA条形码基因进行PCR扩增测序,并从扩增及测序成功率、种内及种间遗传距离、barcoding gap及NJ树等几个方面进行比较,结果表明gyr B基因最适合进行该属内种及亚种的区分,cpn60基因可作为该属分类鉴定的有效补充。     

基于线粒体COⅠ基因的DNA条形码技术在昆虫分子鉴定中的应用

本文对基于线粒体COⅠ基因的DNA条形码技术在昆虫分子鉴定中的应用进行了综述,对DNA条形码的意义、DNA条形码的原理、线粒体COⅠ基因的特点、DNA条形码的操作、DNA条形码技术在昆虫分子鉴定中的应用研究进展、DNA条形码的发展趋势以及有关DNA条形码的争论进行了介绍.     

茶园茶黄蓟马及其近似种的DNA条形码鉴定

基于 mtDNA COI 基因的 DNA 条形码技术是一种新的物种鉴定手段,本文尝试应用该技术对6个不同地理种群的茶黄蓟马与茶园中的其他4种常见蓟马进行了鉴别。测定各种类 mtDNA COI 基因序列并在 BOLD 系统进行比对,采用 MEGA5构建系统进化树,结果表明基于 mtDNACOI 基因的DNA 条形码技术可实现对茶园中茶黄蓟马的快速鉴定。     

植物病原黄单胞菌毒性相关基因对内源 过氧化氢的上游调控作用研究

 以植物病原细菌黄单胞菌的avrXa7基因和ahpC基因的2个突变体及其野生型菌株为研究对象,探讨植物病原细菌内源过氧化氢水平与菌株毒性的联系。AR/HRP法分析病原菌的过氧化氢清除力,组织化学法对细胞内过氧化氢进行定量和定位分析。结果表明,avrXa7基因的突变诱导病原菌毒性的显著降低,并引起病原菌内源过氧化氢积累水平显著下降;ahpC基因的突变诱导病原菌内源过氧化氢水平显著降低,但未能引起病原菌毒性产生显著的变化。研究结果说明,在植物病原细菌黄单胞病菌的致病机制中,病原菌内源过氧化氢的积累水平并不能直接决定菌株的毒性,而是处在avrXa7基因的下游,受到avrXa7或者更多毒性相关基因的调控,参与病原菌的致病过程。     

matK序列作为DNA条形码在苍耳属中的应用

以matK序列作为DNA条形码,对从国外截获的7种苍耳属植物进行物种区分鉴定研究,采用DNeasyOPlantMiniKit试剂盒进行总DNA的提取,应用通用引物对其matK基因进行扩增,测序得到7种苍耳属植物的marK序列,利用MEGA5．1软件对这7种苍耳属植物的matK序列进行比对和分析并构建系统树,结果显示：matK序列能从基因位点层面对苍耳属植物进行区分鉴定。     

植物病原细菌DNA分子检测技术

在DNA检测技术建立之前,种子上的病菌及未显症的病害的快速检测和鉴定几乎是不可能的.随着DNA检测技术的发展,在隐症植物材料上的病害检测变得快速可靠.本文主要介绍DNA检测技术在植物病原细菌检测中的应用.     

DNA条形码在昆虫学中的应用

DNA条形码技术是通过对一段标准化基因DNA序列的分析来实现对生物物种准确、快速鉴定的技术。自2003年提出以来,DNA条形码技术便备受关注,不仅被广泛地应用于生物分类学研究,也为生态学等学科的发展带来了机遇。昆虫是动物界的最大类群,目前条形码数据库中超过65%的序列都来自昆虫纲,DNA条形码的发展无疑为昆虫学带来了勃勃生机。本文综述了DNA条形码的产生、发展、优势及局限,总结并展望了DNA条形码技术在昆虫学基础研究与实践方面的应用。     

植物DNA条形码技术在出入境检验检疫领域的应用

DNA条形码技术是一种通过标准的DNA片段鉴定物种的新技术,已成为近年来生物学研究热点之一。由于DNA条形码技术具有快速、准确、自动等优点,可以满足目前出入境检验检疫工作中提出的"检得出、检得快、检得准"的要求。本文对植物DNA条形码的研究进展进行了概述,分析了该技术在检验检疫应用领域中存在的不足,并针对如何更好地将该技术应用于检验检疫工作中提出了建议。     

运用DNA条形码技术鉴定茶园蜘蛛物种

运用DNA条形码技术,对广东潮州茶园蜘蛛物种进行了分子鉴定。本研究利用基因测序技术获取了凤凰山区域茶园50种蜘蛛的74条线粒体细胞色素C氧化酶亚基I (mitochondrial cytochrome C oxidase subunitⅠ, COⅠ)基因序列。使用邻接法(neighbor joining, NJ)构建系统发育树,运用ABGD(automatic barcode gap discovery)软件对蜘蛛样本进行聚类分析。结果表明:邻接法构建的系统发育树聚类结果与ABGD软件划分结果以及形态分类鉴定结果相一致,运用DNA条形码可以有效地对蜘蛛物种进行分子鉴定。这对茶园蜘蛛疑难物种和新物种的鉴定具有重要意义,在茶园蜘蛛物种多样性的研究中也具有重要价值。由此表明,基于COⅠ基因的DNA条形码对于本研究中所涉及的蜘蛛物种的划分具有较好的区分结果,可以作为一种有效的工具在茶园蜘蛛物种鉴定中进行应用。     

几种常用植物病原细菌分子检测方法

植物病原细菌(phytobacteria)是植物上一类重要的病原菌,这些细菌能引起多种农作物、经济作物、花卉、树木及牧草上的病害。它的快速检测是病害防治、预测预报及植物检疫必不可少的重要工作。其中,以PCR为基础的分子检测技术的进步使植物病原细菌的检测更快速、灵敏和可靠。本文对近年来植物病原细菌分子检测技术进行介绍,尤其是应用广泛的ITS-PCR(intergenictranscribedspace-PCR)、ARDRA(amplifiedribosomalDNArestric-tionanalysis-PCR)、rep-PCR(repetitiveDNA-PCR)和实时荧光定量PCR(real-timequantitativePCR)技术,旨在促进我国植物病原细菌研究的快速发展。     

Dermestid beetles in ‘evolution Canyon’, lower Nahal Oren, Mt. Carmel, including new records for Israel

Fifteen species of dermestid beetles were recorded at ‘Evolution Canyon’ (EC), Lower Nahal Oren, Mt. Carmel, Israel. They represent ~35% of known Israeli dermestid species. The following three species were recorded for the first time in Israel:Trogoderma svriaca Dalla Torre, 1911;Ctesias svriaca Ganglbauer, 1904; andAnthrenus (s.str.) jordaniens Pic, 1934. Adults of 13 species were collected on the more solar radiated, warmer and climatically more fluctuating south-facing slope (SFS); ten species were collected on the opposite, north-facing slope (NFS), which was cooler and climatically more stable. The abundance of adult dermestid beetles was 1.9 times higher on the SFS than on the NFS (86 and 47, respectively). Species richness and abundance distribution at EC (three collecting stations on each slope and one at the valley bottom) were significantly negatively correlated with the plant cover that consisted of trees and bushes (Spearmanr _s ,P=0.007 and 0.039, respectively) and perennials (Spearmanr _s ,P=0.039 and 0.077, respectively), indicating that non-woody plants were preferred by adult dermestid beetles.     

Epidemiology of Toxigenic Fungi and their Associated Mycotoxins for Some Mediterranean Crops

Recent data on the epidemiology of the common mycotoxigenic species of Fusarium, Alternaria, Aspergillus and Penicillium in infected or colonized plants, and in stored or processed plant products from the Mediterranean area are reviewed. Emphasis is placed on the toxigenicity of the causal fungal species and the natural occurrence of well known mycotoxins (aflatoxins, ochratoxins, fumonisins, trichothecenes, zearalenone, patulin, Alternaria-toxins and moniliformin), as well as some more recently described compounds (fusaproliferin, beauvericin) whose toxigenic potential is not yet well understood. Several Fusarium species reported from throughout the Mediterranean area are responsible of the formation of mycotoxins in infected plants and in plant products, including: Fusarium graminearum, F. culmorum, F. cerealis, F. avenaceum, F. sporotrichioides and F. poae, which produce deoxynivalenol, nivalenol, fusarenone, zearalenone, moniliformin, and T-2 toxin derivatives in wheat and other small grains affected by head blight or scab, and in maize affected by red ear rot. Moreover, strains of F. verticillioides, F. proliferatum, and F. subglutinans, that form fumonisins, beauvericin, fusaproliferin, and moniliformin, are commonly associated with maize affected by ear rot. Fumonisins, were also associated with Fusarium crown and root rot of asparagus and Fusarium endosepsis of figs, caused primarily by F. proliferatum. Toxigenic A. alternata strains and associated tenuazonic acid and alternariols were commonly found in black mould of tomato, black rot of olive and citrus, black point of small cereals, and black mould of several vegetables. Toxigenic strains of A. carbonarius and ochratoxin A were often found associated with black rot of grapes, whereas toxigenic strains of A. flavus and/or P. verrucosum, forming aflatoxins and ochratoxin A, respectively, were found in moulded plant products from small cereals, peanuts, figs, pea, oilseed rape, sunflower seeds, sesame seeds, pistachios, and almonds. Finally, toxigenic strains of P. expansum and patulin were frequently found in apple, pear and other fresh fruits affected by blue mould rot, as well as in derived juices and jams.     

A survey of the genera of<Emphasis Type="Italic">Microgaster</Emphasis> latreille and<Emphasis Type="Italic">Hygroplitis</Emphasis> thomson (Hymenoptera: Braconidae: Microgastrinae) from China

The genera ofMicrogaster Latreille 1804 andHygroplitis Thomson 1895 from China are presented systematically in this paper. Thirty-two species ofMicrogaster and three species ofHygroplitis are known in China. Diagnosis, character variation, distribution and host of each species among the two genera are presented, including its host and distribution. Keys to the species ofMicrogaster andHygroplitis are given. http://www.phytoparasitica.org posting Dec. 19, 2006.     

Plant Viruses Transmitted by Whiteflies

One-hundred and fourteen virus species are transmitted by whiteflies (family Aleyrodidae). Bemisia tabaci transmits 111 of these species while Trialeurodes vaporariorum and T. abutilonia transmit three species each. B. tabaci and T. vaporariorum are present in the European–Mediterranean region, though the former is restricted in its distribution. Of the whitefly-transmitted virus species, 90% belong to the Begomovirus genus, 6% to the Crinivirus genus and the remaining 4% are in the Closterovirus, Ipomovirus or Carlavirus genera. Other named, whitefly-transmitted viruses that have not yet been ranked as species are also documented. The names, abbreviations and synonyms of the whitefly-transmitted viruses are presented in tabulated form together with details of their whitefly vectors, natural hosts and distribution. Entries are also annotated with references. Whitefly-transmitted viruses affecting plants in the European–Mediterranean region have been highlighted in the text.     

Broad bean mottle virus in Morocco; curculionid vectors,and natural occurrence in food legumes other than faba bean (Vicia faba)

Broad bean mottle virus (BBMV) was transmitted from infected to healthy faba-bean plants by the curculionid weevilsApion radiolus Kirby,Hypera variabilis Herbst,Pachytychius strumarius Gyll,Smicronyx cyaneus Gyll, andSitona lineatus L. The latter appeared to be an efficient vector: acquisition and inoculation occurred at the first bite, the rate of transmission was c. 41%, and virus retention lasted for at least seven days.S. lineatus transmitted the virus from faba bean to lentil and pea, but not to the three genotypes of chickpea tested. This is the first report on the generaHypera, Pachytychius, andSmicronyx as virus vectors, and onA. radiolus, H. variabilis, P. strumarius, andS. cyaneus as vectors of BBMV.Out of 351 samples of food legumes with symptoms suggestive of virus infection, 16, 11, 19, and 17% of the samples of chickpea, lentil, pea, and common bean, respectively, were found infected when tested for BBMV in DAS-ELISA. This is the first report on the natural occurrence of BBMV in chickpea, lentil, pea, and common bean. The virus should be regarded as a food-legume virus rather than a faba-bean virus solely, and is considered an actual threat to food legume improvement programmes.     

Characterization of potato potyvirus Y (PVY) isolates from seed potato batches. Situation of the NTN, Wilga and Z isolates

A collection of 38 PVY isolates from seed potato batches, originating from several Western European countries, was characterized by using current biological, serological and molecular tools differentiating PVY strains and groups. The correlation between the three kinds of tests was good but not absolute. No single serological or PCR method was able to discriminate among the five isolate groups found. Twenty-nine isolates belonged to the PVY^N strain and six to the PVY^O strain. No PVY^C was found. Two other isolates reacted serologically like PVY^O, but were unable to elicit a hypersensitive response from the Ny_tbr gene and probably represent the PVY^Z group. At the molecular level, these two isolates showed a combination of both PVY^O and PVY^N and could be recombinants of these strains. Another isolate reacted serologically like PVY^O, but induced vein necrosis in tobacco, like PVY^N-Wilga. Some PVY^N isolates caused tuber ring necrosis in glasshouse conditions. These might belong to the PVY^NTN group. The PVY^NTN, PVY^N-Wilga and PVY^Z groups probably represent pathotypes within strains PVY^N and PVY^O, respectively. The present study also confirms previous reports showing a high genetic variation at the 5 end within the PVYN strain.     

The autumn leafroller: Phenology,damage and parasitoids in a Dutch apple orchard

The phenology of the autumn leafroller,Syndemis musculana, a local pest of apple, was studied in order to forecast larval emergence. From 1983–1986, peak flight as determined with sexpheromone traps was always between 13–18 May. The duration of embryonic development was determined at various constant temperatures and used to estimate the periods of egg hatch in these four years. Each year, most eggs should have hatched in the second decade of June.Differences in attack rates between apple cultivars seem to be explained largely by the variation in picking time. Larvae are only half grown at the beginning of harvest (cv. James Grieve), and have gone into hibernation when the latest variety (cv. Golden Delicious) is picked. Moreover, the varieties Cox's Orange Pippin and Belle de Boskoop, picked about half time, are liable to receive additional damage by caterpillars brought with the picked fruits into storage.Various hymenopterous parasites were reared from caterpillars. As the only leafroller in the orchard which hibernates as mature larva,S. musculana may promote winter survival of some parasitoids, like the eulophidColpyclypeus florus.Samenvatting De fenologie van de herfstbladroller (Syndemis musculana Hübner), een incidentele plaag op appel, werd nader bepaald met het doel het uitkomen van de eieren te kunnen voorspellen. In 1983–1986 viel de piekvlucht, bepaald met behulp van feromoonvallen, steeds tussen 13 en 18 mei.De ontwikkelingsduur van de eieren bij verschillende constante temperaturen werd gebruikt om de periode van uitkomen te schatten. De meeste eieren zullen ieder jaar in de eerste helft van juni uitkomen.Geconstateerde verschillen in schade tussen appelrassen blijken goeddeels terug te voeren op verschillen in pluktijdstip. De rupsen van de herfstbladroller zijn pas half-was als de eerste appels eind augustus geplukt worden, terwijl tegen het einde van de oogst begin oktober de meeste al in winterslaap zijn. Met name tussentijdse rassen, als Cox's Orange Pippin and Schone van Boskoop, lopen extra schade op doordat grotere rupsen met de geplukte vruchten in de kist terecht komen.Uit de rupsen werden negen, al van andere boomgaardbladrollers bekende, sluipwespen gekweekt, Omdat deze bladrollersoort, als enige in de boomgaard, als volgroeide rups overwintert, lijkt zij bij uitstek geschikt als winterwaard.This study was carried out at the Experimental Orchard De Schuilenburg, Schuilenburg 3, 4041 BK Kesteren, the Netherlands, to which address correspondence should be addressed.     

Diagnostics,genetic diversity and pathogenic variation of ascochyta blight of cool season food and feed legumes

Molecular diagnostic techniques have been developed to differentiate the Ascochyta pathogens that infect cool season food and feed legumes, as well as to improve the sensitivity of detecting latent infection in plant tissues. A seed sampling technique was developed to detect a 1% level of infection by Ascochyta rabiei in commercial chickpea seed. The Ascochyta pathogens were shown to be genetically diverse in countries where the pathogen and host have coexisted for a long time. However, where the pathogen was recently introduced, such as A. rabiei to Australia, the level of diversity remained relatively low, even as the pathogen spread to all chickpea-growing areas. Pathogenic variability of A. rabiei and Ascochyta pinodes pathogens in chickpea and field pea respectively, appears to be quantitative, where measures of disease severity were based on aggressiveness (quantitative level of infection) rather than on true qualitative virulence. In contrast, qualitative differences in pathogenicity in lentil and faba bean genotypes indicated the existence of pathotypes of Ascochyta lentis and Ascochyta fabae. Therefore, reports of pathotype discrimination based on quantitative differences in pathogenicity in a set of specific genotypes is questionable for several of the ascochyta-legume pathosystems such as A. rabiei and A. pinodes. This is not surprising since host resistance to these pathogens has been reported to be mainly quantitative, making it difficult for the pathogen to overcome specific resistance genes and form pathotypes. For robust pathogenicity assessment, there needs to be consistency in selection of differential host genotypes, screening conditions and disease evaluation techniques for each of the Ascochyta sp. in legume-growing countries throughout the world. Nevertheless, knowledge of pathotype diversity and aggressiveness within populations is important in the selection of resistant genotypes.     

Characterization of Sclerotinia minor populations in Texas peanut fields

In the summer of 2004 an epidemic of sclerotinia blight of peanut, a disease caused by Sclerotinia minor, occurred in Texas in fields where the disease was never previously detected. The disease was observed on many plants within one of the fields (>3000 disease foci), although most foci were <1 m. It is hypothesized that these observations were inconsistent with the recent introduction of a monocyclic pathogen, even if disease developed under conducive environmental conditions. The pattern of disease is most suggestive of the presence of foliar (ascospore) infections, although air temperature was above the known limits for apothecia development if the pathogen had arrived in the field in 2004 peanut seed. To further examine this epidemic, 232 isolates were collected, across a variety of spatial scales spanning this field and other Texas peanut fields, and evaluated for aggressiveness, fungicide sensitivity and genotypic diversity. There was wide variation among isolates for the phenotypic characteristics measured, but there was no evidence that a genotypically unique, highly aggressive, and fungicide resistant isolate had been introduced or evolved. The predominant genotype, TX1, which contained 154 isolates, was found in every county and field population.     

Eyespot of Cereals Revisited: ITS phylogeny Reveals New Species Relationships

Four species so far classified in Pseudocercosporella or Ramulispora (hyphomycetes) are associated with eyespot disease symptoms of cereals. Two of these have been linked to teleomorphs that were described in Tapesia. Sequence data derived from the Internal Transcribed Spacer region (ITS1, 5.8S and ITS2) of the rDNA operon showed, however, that the eyespot fungi associated with Tapesia are not congeneric with Ramulispora sorghi, the type of Ramulispora. The genus name Tapesia is now rejected in favour of the conserved name Mollisia, which appears to comprise heterogeneous fungi. Tapesia yallundae is not closely related to the type of Mollisia, M. cinerea, but clusters separately, being more closely allied to species with Cadophora anamorphs. A new holomorph genus, Oculimacula, is therefore proposed for teleomorphs of the eyespot fungi, while the anamorphs are accommodated in Helgardia gen. nov.