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菠萝粉蚧是为害菠萝的粉蚧的统称,是菠萝凋萎病的主要传播媒介,本文对我国菠萝粉蚧的种类和发生规律进行了研究.结果表明:在我国,为害菠萝的粉蚧主要是菠萝洁粉蚧,仅在海南乐东菠萝园发现有新菠萝灰粉蚧危害;菠萝洁粉蚧目前仅限在菠萝上为害;新菠萝灰粉蚧主要为害剑麻,也为害菠萝和粉蕉;我国暂未发现2种粉蚧混合发生的现象.秋季是雷州半岛地区菠萝洁粉蚧自然种群快速增长期,12月下旬菠萝洁粉蚧自然种群数量进入高峰期;气温和降雨量是影响菠萝洁粉蚧自然种群增长的重要因子,高温、低温均不利于菠萝洁粉蚧生长和繁殖,降雨量对菠萝洁粉蚧的自然种群数量具有明显的抑制作用. 相似文献
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大洋臀纹粉蚧Planococcus minor Maskell和南洋臀纹粉蚧Planococcus lilacius Cockerell是我国有重要检疫意义的有害生物。从这两种蚧虫的分布状况、受害栽培寄主、潜在危害性、传播扩散的可能性及危险性管理难度等5个方面对其在我国南方特别是福建省热区的风险性进行了定量分析,表明这两种蚧虫在福建省热区是高度危险的检疫性有害生物,并据此提出了初步风险管理对策。 相似文献
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永乐群岛岛礁植物虫害发生与危害状况迄今未见报道。为了有效监控永乐群岛外来有害生物的入侵、定殖扩散与爆发成灾,本研究对永乐群岛5个岛屿的害虫进行了系统性普查及安全性评估。结果表明,永乐群岛5个岛屿97种野生盐生植物、绿色固沙植物、耐盐蔬菜上共查获害虫（螨）83种,其中,晋卿岛38种植物上共发现26种害虫（螨）发生危害;甘泉岛30种植物上共发现20种害虫（螨）发生危害;银屿16种植物上共发现14种害虫（螨）发生危害;鸭公岛5种植物上共发现12种害虫（螨）发生危害;羚羊礁10种植物上共发现12种害虫发生危害。调查首次发现扶桑绵粉蚧（Phenacoccus solenopsis）、新菠萝灰粉蚧（Dysmicoccus neobrevipes）、美洲斑潜蝇（Liriomyza sativae）、拟三色星灯蛾（Utetheisa lotrix）、蔷薇三节叶蜂（Arge geei）、榕蓟马（Gynaikothrips ficorum）、朱砂叶螨（Tetranychus cinnabarinus）等危险性害虫在5个岛屿32种植物生严重发生和危害。针对国家检疫性毁灭性害虫扶桑绵粉蚧、新菠萝灰粉蚧安全性评估结果表明,这2种害虫的风险评估指数R值分别为2.21和2.23,在永乐群岛均属于高度危险有害生物,应严格管控。本研究对于可持续防控永乐群岛岛礁植物虫害的发生危害和保护生态环境、保障当地宜居环境和岛礁作物安全生产,均具有十分重要的理论与实际意义。 相似文献
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为了有效监控赵述岛岛礁害虫发生与危害，对赵述岛90种岛礁植物害虫进行系统性普查及外来危险性害虫风险评估。结果表明，8种野生盐生植物上共查获害虫17种、害螨2种，其中5种外来入侵害虫和7种世界危险性害虫严重发生与危害；29种园林绿化植物上共查获害虫22种、害螨2种，其中9种外来危险性害虫和6种世界危险性害虫严重发生与危害；31种耐盐果树和蔬菜上共查获害虫32种、害螨4种，其中7种外来入侵害虫和6种世界危险性害虫严重发生与危害；22种绿色固沙植物上共查获害虫14种、害螨2种，其中5种外来入侵害虫和2种世界危险性害虫严重发生与危害。风险评估结果表明，椰心叶甲（Brontispa longissima）、木瓜秀粉蚧（Paracoccus marginatus）、扶桑绵粉蚧（Phenacoccus solenopsis）和椰子织蛾（Opisina arenosella）的综合风险值（R）分别为2.12、2.12、2.09、2.02，在赵述岛均属于高度危险有害生物；新菠萝灰粉蚧（Dysmicoccuneobrevipes）、波氏白背盾蚧（Diaspisboisduvalii）、二斑叶螨（Tetra... 相似文献
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为了有效监控永兴岛危险性害虫发生与危害,本研究对永兴岛可调查的所有陆地区域野生盐生植物、园林绿化植物、耐盐果蔬和绿色固沙植物害虫进行系统性普查及风险评估。普查结果表明：8种野生盐生植物上害虫（螨）19种,其中5种外来入侵害虫和11种世界危险性害虫普遍严重发生与危害;57种园林绿化植物上害虫（螨）33种,其中9种外来入侵害虫和17种世界危险性害虫普遍严重发生与危害;31种耐盐果蔬害虫（螨）36种,其中7种外来入侵害虫和20种世界危险性害虫普遍严重发生与危害;22种绿色固沙植物害虫（螨）15种,其中5种外来入侵害虫和5种世界危险性害虫普遍严重发生与危害。风险评估结果表明,椰心叶甲（Brontispa longissima）、木瓜秀粉蚧（Paracoccus marginatus）、扶桑绵粉蚧（Phenacoccus solenopsis）的综合风险值（R）均为2.09,在永兴岛均属于高度危险有害生物,椰子织蛾（Opisina arenosella）、波氏白背盾蚧（Diaspis boisduvalii）、新菠萝灰粉蚧（Dysmicoccu neobrevipes）、烟粉虱（Bemisia tabaci）、棕榈蓟马（Thrips palmi）、二斑叶螨（Tetranychus urticae）、瓜实蝇（Bactrocera cucuribitae）和美洲斑潜蝇（Liriomyza sativae）的R值分别为1.99、1.97、1.93、1.87、1.87、1.87、1.82和1.79,在永兴岛均属于中度危险有害生物。上述结果为永兴岛岛礁植物害虫发生与危害情况首次报道,为有效监控永兴岛生物安全提供了重要的基础信息支撑。 相似文献
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1株广谱抗真菌芽孢杆菌TR21的鉴定 总被引：2，自引：0，他引：2
利用API50CH鉴定系统、16S rDNA、gyrA和gyrB基因序列分析法,对1株分离自石斛兰叶片的广谱抗真菌芽孢杆菌TR21进行生化和分子鉴定。通过API50CH系统测试,TR21菌株与枯草芽孢杆菌相似性为90.3%,被鉴定为枯草芽孢杆菌。利用16SrDNA序列分析发现TR21菌株与枯草芽孢杆菌(Bacillus subtilis)、B.subtilis subsp.subtilis、B.subtilis subsp.spizizenii和B.velezensis的相应核苷酸序列具有很高的同源性,其序列相似性皆为99%,而基于gyrA和gyrB基因序列构建的系统发育树显示,该菌株与枯草芽孢杆菌的相似性分别为96%和91%。结合16SrDNA、gyrA和gyrB基因序列分析,也确定该菌为枯草芽孢杆菌。比较API鉴定和基于不同基因的鉴定发现,分子鉴定更加快速、灵敏。 相似文献
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利用ITS1和ITS4通用引物扩增香蕉枯萎病菌核酸片段鉴定其生理小种 总被引：8，自引：2，他引：6
利用真菌核糖体rDNA区通用引物ITS1和ITS4,扩增采集自香蕉的13株镰刀菌包括18S rDNA部分序列、ITS1-5.8S-ITS2全部序列和28S rDNA部分序列的片段,通过BLAST序列比对分析,确定13株菌为尖孢镰刀菌[Fusarium oxysporum]。采用最大简约法,以层出镰刀菌[F.proliferatum(EU151490)]和茄病镰刀菌[F.solani(GQ376116)]为外群,将13株菌的序列与BLAST检索获得的尖镰孢古巴专化型(F.oxysporum f.sp.Cubense)相应序列构建了系统发育树。系统发育分析结果显示,13株菌与NCBI登录的4个尖镰孢古巴专化型菌株一起被分成3个亚群,亚群聚类结果与回接鉴定结果及文献报道的生理小种结果完全一致。 相似文献
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桑树青枯病是由青枯雷尔氏菌引起的细菌性病害,热带、亚热带地区发病严重,严重影响蚕桑产业的可持续发展。雷尔氏菌不同种间致病力和宿主各不相同,其防治策略也相应不同,准确地分离鉴定病原菌是青枯病有效防控的先决条件。本研究采集、分离了海南省琼中县桑青枯病发病桑园（‘桂桑优62’）桑树根部、茎部病原菌,并通过致病性、生理小种、生化变种测定,结合16S rDNA、特异性引物、复合PCR检测体系、序列变种等分子鉴定方法初步确定了病原菌的种类和分类地位。结果表明,引发海南省琼中县桑青枯病的病原菌属于青枯雷尔氏菌（Ralstonia solanacearum）、生理小种5（race 5）、生化变种Ⅴ（biovar Ⅴ）,病原菌遗传进化分析结果显示病原菌属演化型Ⅰ（phylotype Ⅰ）即亚洲分支菌株,序列变种12（sequevar 12）。这些结果将为海南桑青枯病的有效防控奠定基础。 相似文献
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基于ITS2条形码的南药巴戟天真伪鉴别 总被引：1，自引：0，他引：1
本研究旨在建立基于ITS2条形码的巴戟天及其混伪品的真伪鉴别方法。采用试剂盒提取巴戟天植物样品的总DNA,以一对通用引物对其ITS2条形码进行PCR扩增并测序;从Genbank数据库获取巴戟天及其混伪品ITS2序列。采用DNAMAN、ClustalX软件拼接比对序列,以及利用MEGA5.1软件构建NJ树。获得的22条ITS2序列的长度范围为224~244 bp,GC含量范围为59.8%~70.1%。巴戟天与8种混伪品的ITS2序列存在155处变异,种间K2P遗传距离远大于种内K2P遗传距离。基于ITS2条形码的NJ聚类树能直观地区分巴戟天及其混伪品。因此,ITS2条形码适用于南药巴戟天及其混伪品的鉴别,可为其基原研究提供重要的分子鉴定证据。 相似文献
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为明确广西贺州市栀子根结线虫病病原种类,采集根部有明显根结的栀子根系进行根结线虫分离鉴定,通过观察根结线虫2龄幼虫、雌成虫、会阴花纹特征对其进行形态学鉴定,并利用核糖体ITS区和28S rDNA D2D3区序列比对和系统发育树分析方法对其进行分子生物学鉴定。结果表明,该病原线虫2龄幼虫和雌成虫形态特征及形态测量值与象耳豆根结线虫（Meloidogyne enterolobii Yang & Eisenback, 1983）相似;该病原线虫核糖体ITS区与NCBI数据库中象耳豆根结线虫相应序列的相似度为100%,28S rDNA D2D3区与NCBI数据库中象耳豆根结线虫相应序列的相似度为99%以上;该病原线虫核糖体ITS序列以99%的支持率与象耳豆根结线虫聚为同一分支。综合形态学和分子生物学鉴定结果将广西贺州市栀子根结线虫病病原种类鉴定为象耳豆根结线虫,栀子（Gardenia jasminoides Eills）是该线虫的新寄主纪录。 相似文献
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An antagonist yeast strain, WY-1, was identified using 18S and internal transcribed spacer (ITS) 1-5.8S-ITS2 rDNA region sequences. The 18S and ITS1-5.8S-ITS2 rDNA sequences of this yeast strain were amplified and sequenced using the universal primer pairs NS1/NS8 and ITS4/ITS5. The ITS1-5.8S-ITS2 rDNA sequence and 18S neighbor-joining tree showed that WY-1 was a strain of Cryptococcus albidus. The biocontrol activity of C. albidus WY-1 on postharvest decay of radishes caused by Alternaria spp. and Fusarium spp. was investigated. In vitro, at 108 CFU ml−1 C. albidus WY-1 inhibited the mycelial weight increases of Alternaria spp. and Fusarium spp. by 45.3% and 59.6%, respectively. In vivo, infection incidence and lesion development of radish decay were suppressed by the application of C. albidus WY-1 at 108 CFU ml−1. After 6 days of incubation at 20 °C or 24 days at 4 °C, disease incidences were 2.8% and 1.4%, respectively; however, the disease incidences of control fruit were 98.6% and 87.5% under these incubation conditions, respectively. Application of C. albidus WY-1 and the chemical fungicide thiabendazole were statistically just as effective. Finally, C. albidus cell counts around inoculation sites remained high at 4 °C even 32 days after inoculation (6.7 × 105 CFU per cm2). 相似文献
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The nuclear rDNA regions of the two internal transcribed spacers (ITS1 and ITS2) and 5.8S rRNA gene from 52 field isolates ofSpongospora subterranea f.sp.subterranea obtained from the British Isles and North America were polymerase chain reaction-amplified, sequenced, and assessed for genetic variation. Two genetically distinct groups (I and II) were identified based on the ITS sequence diversity among the isolates, representing 34.6% and 65.4% of the isolates, respectively. British Isles isolates occurred in groups I and II, whereas North American isolates belonged only to group II. The British Isles groups ofS. subterranea were associated with particular potato cultivars. The full-length small-subunit rRNA gene ofS. subterranea was sequenced and analyzed by both neighbor-joining and parsimony methods to clarify the taxonomic position of this pathogen. The results of phylogenetic analysis showed thatS. subterranea grouped together with other species of plasmodiphorids, and this group clustered with the phylum Cercozoa, an assemblage of filose and reticulose amoebae and phylogenetically related zooflagellates. The recognition of the existence of different genetic groups withinS. subterranea will be important for the design of plant-breeding programs and in testing for plant resistance. 相似文献
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以玉米根系为例,建立植物根系丛枝菌根18SrRNA基因克隆文库构建的方法。CTAB法提取的丛枝菌根真菌总DNA能够满足后续PCR扩增的要求。运用真菌引物GeoA2/Geo11及AMF特异引物AM1、AM2、AM3/NS31进行巢式PCR扩增,获得的产物连接转化入大肠杆菌构建18SrRNA部分基因克隆文库。通过限制性内切酶Hinf I、TaqI对随机挑选的50个克隆子进行ARDRA(Amplified Ribosomal DNA Restriction Analysis)分析,共获得11个差异图谱。每个图谱选择1个代表测序,结果表明,3个序列为玉米自身未知基因,其余8个都为Clomus属序列。文库评价统计结果发现,AMF克隆文库的Coverage值为72.4%,Rarefaction曲线趋于平缓,所建立文库的容量较为充足,能较全面地代表玉米根系AMF的多样性。 相似文献
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Characterization of Streptomyces spp. Isolated from the Sea Surface Microlayer in the Trondheim Fjord, Norway 
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下载免费PDF全文 Sigrid Hakvg Espen Fjrvik Kjell D. Josefsen Elena Ian Trond E. Ellingsen Sergey B. Zotchev 《Marine drugs》2008,6(4):620-635
The water surface microlayer is still poorly explored, although it has been shown to contain a high density of metabolically active bacteria, often called bacterioneuston. Actinomycetes from the surface microlayer in the Trondheim fjord, Norway, have been isolated and characterized. A total of 217 isolates from two separate samples morphologically resembling the genus Streptomyces have been further investigated in this study. Antimicrobial assays showed that about 80% of the isolates exhibited antagonistic activity against non-filamentous fungus, Gram-negative, and Gram-positive bacteria. Based on the macroscopic analyses and inhibition patterns from the antimicrobial assays, the sub-grouping of isolates was performed. Partial 16S rDNAs from the candidates from each subgroup were sequenced and phylogenetic analysis performed. 7 isolates with identical 16S rDNA sequences were further studied for the presence of PKS type I genes. Sequencing and phylogenetic analysis of the PKS gene fragments revealed that horizontal gene transfer between closely related species might have taken place. Identification of unique PKS genes in these isolates implies that de-replication can not be performed based solely on the 16S rDNA sequences. The results obtained in this study suggest that streptomycetes from the neuston population may be an interesting source for discovery of new antimicrobial agents. 相似文献
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Species of Penicillium section Citrina have a worldwide distribution and occur commonly in soils. The section is here delimited using a combination of phenotypic characters and sequences of the nuclear ribosomal RNA gene operon, including the internal transcribed spacer regions ITS1 and ITS2, the 5.8S nrDNA (ITS) and partial RPB2 sequences. Species assigned to section Citrina share the production of symmetrically biverticillate conidiophores, flask shaped phialides (7.0-9.0 μm long) and relatively small conidia (2.0-3.0 μm diam). Some species can produce greyish-brown coloured cleistothecia containing flanged ascospores. In the present study, more than 250 isolates presumably belonging to section Citrina were examined using a combined analysis of phenotypic and physiological characters, extrolite profiles and ITS, β-tubulin and/or calmodulin sequences. Section Citrina includes 39 species, and 17 of those are described here as new. The most important phenotypic characters for distinguishing species are growth rates and colony reverse colours on the agar media CYA, MEA and YES; shape, size and ornamentation of conidia and the production of sclerotia or cleistothecia. Temperature-growth profiles were made for all examined species and are a valuable character characters for species identification. Species centered around P. citrinum generally have a higher maximum growth temperature (33-36 °C) than species related to P. westlingii (27-33 °C). Extrolite patterns and partial calmodulin and β-tubulin sequences can be used for sequence based identification and resolved all species. In contrast, ITS sequences were less variable and only 55 % of the species could be unambiguously identified with this locus. TAXONOMIC NOVELTIES: Penicillium argentinense Houbraken, Frisvad & Samson, P. atrofulvum Houbraken, Frisvad & Samson, P. aurantiacobrunneum Houbraken, Frisvad & Samson, P. cairnsense Houbraken, Frisvad & Samson, P. christenseniae Houbraken, Frisvad & Samson, P. copticola Houbraken, Frisvad & Samson, P. cosmopolitanum Houbraken, Frisvad & Samson, P. neomiczynskii Cole, Houbraken, Frisvad & Samson, P. nothofagi Houbraken, Frisvad & Samson, P. pancosmium Houbraken, Frisvad & Samson, P. pasqualense Houbraken, Frisvad & Samson, P. quebecense Seifert, Houbraken, Frisvad & Samson, P. raphiae Houbraken, Frisvad & Samson, P. terrigenum Seifert, Houbraken, Frisvad & Samson, P. ubiquetum Houbraken, Frisvad & Samson, P. vancouverense Houbraken, Frisvad & Samson, P. wellingtonense Cole, Houbraken, Frisvad & Samson. 相似文献
18.
华山新麦草是我国华山地区特有小麦近缘物种，具有抗逆、早熟、优质等特点，对小麦的白粉病、条锈病、赤霉病也具有良好的抗性，是小麦重要的三级基因库。为进一步更好地发挥华山新麦草基因资源的作用，本研究利用细胞学方法、原位杂交技术、分子标记技术、农艺性状评估和抗病性鉴定对普通小麦-华山新麦草衍生后代材料进行鉴定，并获得了 20H11、17H21、18H28 三个小麦-华山新麦草衍生系。结果表明，20H11、17H21 和 18H28 的染色体数都是 44 条，均携带2 条属于华山新麦草的 Ns 染色体和 42 条普通小麦染色体。利用华山新麦草的特异分子标记进行检测，证明 20H11、17H21 和 18H28分别为 3Ns、4Ns和 2Ns二体附加系。通过农艺性状调查，3个试验异染色体系与亲本7182相比，株高和小穗粒数的差异不显著；分蘖数目与亲本7182有显著差异；20H11的穗长显著短于亲本7182；17H21的分蘖数显著少于亲本7182。经条锈病抗性鉴定，18H28 高抗条锈病小种 CYR32 和 CYR34。因此，这三个华山新麦草衍生系可作为中间材料用于小麦遗传育种研究。 相似文献
19.
叶绿体基因组在物种鉴定、系统进化分析及亲缘关系研究等领域应用前景广阔。本文应用Illumina高通量测序技术对龙井43（Camellia sinensis cv. Longjing 43）的叶绿体全基因组进行测序;利用叶绿体trnL-trnF序列研究茶树及其近缘植物的亲缘关系。结果表明,龙井43叶绿体基因组全长为157 096 bp,反向互补重复区（Inverted repeat, IR）为26 080 bp,小单拷贝区（Small single copy region, SSC）、大单拷贝区（Large single copy region, LSC）分别为18 283 bp、86 653 bp。共注释叶绿体基因133个,其中蛋白编码基因86个,rRNA基因8个,tRNA基因39个。对所选植物的trnL-trnF序列进行比对,序列长度变异范围为481~501 bp,序列最长为岔河大茶,最短为金花茶,基于此序列构建亲缘关系树,山茶属茶组植物聚成一个组。研究结果对茶树优良品种培育及山茶属植物亲缘关系的研究具有重要价值。 相似文献