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1.
香蕉炭疽菌rDNA ITS区的分子鉴定与检测   总被引:15,自引:0,他引:15  
 香蕉炭疽病菌(Colletordchum muscat)是一种引起香蕉采后病害的最重要病原,本研究用真菌18S~28S间的内转录间隔区(internal transcribed spacer,ITS)通用引物18SF和28SR扩增香蕉炭疽菌和其它外群真菌的基因组DNA,扩增出约510bp的片段;通过克隆测序香蕉炭疽菌的ITS全序列并与GenBank中炭疽菌属其它种的ITS序列比对,设计出香蕉炭疽菌的特异性引物ColM1和ColM2。用此特异引物可以从香蕉炭疽菌株中扩增出382bp的特异性片段,而其余20个参试菌株和香蕉组织的PCR反应结果为阴性,灵敏度实验证明可以检测到目标DNA的浓度为0.1Pg。该方法可用于快速、准确和灵敏地检测香蕉炭疽菌,为快速监测组织中有无香蕉炭疽病菌潜伏侵染与及早采取防治措施提供积极的指导意义。  相似文献   

2.
小麦纹枯病菌核糖体基因内转录区序列比较   总被引:12,自引:1,他引:12  
 对7个从江苏省小麦纹枯病样本分离到的丝核菌菌株,进行形态学鉴定、融合群分类和致病性测定,提取病菌的DNA,采用通用引物ITS1(TCC GTA GGT GAA CCT GCG G)和ITS4(TCC TCC GCT TAT TGA TAT GC),扩增病菌的rDNA内转录区(ITS),并对扩增产物进行了测序.用这些序列在NCBI中进行BLAST分析,得到与这些菌株亲缘关系最近的菌株序列,并明确了这些菌株的分类地位.对以上的菌株序列进行Alignment分析,结果表明,病菌的5.8S rDNA序列高度保守,而ITS区的可变性则相对较高,在双核和多核丝核菌、双核丝核菌CAG1融合群和非CAG1融合群菌株间存在差异,可用于反映菌株间的进化关系和双核丝核菌种下分类.  相似文献   

3.
ABSTRACT Most of the 3,000 named species in the genus Cercospora have no known sexual stage, although a Mycosphaerella teleomorph has been identified for a few. Mycosphaerella is an extremely large and important genus of plant pathogens, with more than 1,800 named species and at least 43 associated anamorph genera. The goal of this research was to perform a large-scale phylogenetic analysis to test hypotheses about the past evolutionary history of Cercospora and Mycosphaerella. Based on the phylogenetic analysis of internal transcribed spacer (ITS) sequence data (ITS1, 5.8S rRNA gene, ITS2), the genus Mycosphaerella is monophyletic. In contrast, many anamorph genera within Mycosphaerella were polyphyletic and were not useful for grouping species. One exception was Cercospora, which formed a highly supported monophyletic group. Most Cercospora species from cereal crops formed a subgroup within the main Cercospora cluster. Only species within the Cercospora cluster produced the toxin cercosporin, suggesting that the ability to produce this compound had a single evolutionary origin. Intraspecific variation for 25 taxa in the Mycosphaerella clade averaged 1.7 nucleotides (nts) in the ITS region. Thus, isolates with ITS sequences that differ by two or more nucleotides may be distinct species. ITS sequences of groups I and II of the gray leaf spot pathogen Cercospora zeae-maydis differed by 7 nts and clearly represent different species. There were 6.5 nt differences on average between the ITS sequences of the sorghum pathogen Cercospora sorghi and the maize pathogen Cercospora sorghi var. maydis, indicating that the latter is a separate species and not simply a variety of Cercospora sorghi. The large monophyletic Mycosphaerella cluster contained a number of anamorph genera with no known teleomorph associations. Therefore, the number of anamorph genera related to Mycosphaerella may be much larger than suspected previously.  相似文献   

4.
To elucidate the demographic history within and among the genera Pseudopestalotiopsis, Neopestalotiopsis, and Pestalotiopsis and their genetic diversity, we studied internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA (nrDNA) with no saturation effects in 172 Pestalotiopsis-like fungal accessions isolated from Camellia sinensis planted in nine provinces in China (64 from Yunnan, 4 from Guangxi, 2 from Guizhou, 42 from Jiangxi, 3 from Sichuan, 3 from Zhejiang, 1 from Henan, 18 from Fujian, 12 from Chongqing, and 18 from other provinces) and in Japan (1), France (1), Turkey (1), and Thailand (2). Among these, 44 Pestalotiopsis-like isolates from Yunnan in this study formed a clade in phylogenetic trees with Pestalotiopsis accessions in GenBank, despite their cultural characteristics on potato dextrose agar displaying no genus specificity. Based on estimated sequence polymorphism parameters of average pairwise differences (K), haplotype diversity (Hd), nucleotide diversity (Pi), θ (per site) from η, and recombination event rate (Rm), we identified moderate genetic variation in these three genera. Molecular evolution analysis with neutrality tests and mismatch distribution demonstrated that Pseudopestalotiopsis and Pestalotiopsis ribosomal ITS sequences evolved under a neutral model. However, the recent demographic expansion of the three genera promoted geographical isolation but showed no clear geographical structure. Pairwise genetic divergences between haplotypes and a median-joining network revealed Yunnan or Jiangxi as a possible centre of origin, and that Pseudopestalotiopsis and Neopestalotiopsis may derive from Pestalotiopsis.  相似文献   

5.
麻文建  朱天辉  韩珊 《植物保护》2015,41(4):125-130
寄生隐丛赤壳菌是引起板栗疫病的致病菌。为建立该菌的分子检测技术,本研究首先采用通用引物ITS1/ITS4对分离自四川雅安、泸州及重庆的寄生隐丛赤壳菌及其他参试菌株的ITS区进行PCR扩增和测序比对。根据该片段与GenBank中隐丛赤壳属其他种的ITS序列差异,设计了寄生隐丛赤壳菌的特异性引物ITSP1/ITSP2,片段扩增大小为462bp。利用该引物对菌株基因组DNA进行扩增,可以将寄生隐丛赤壳菌与其他参试菌区分开,检测灵敏度达30pg。而以引物ITS1/ITS4和ITSP1/ITSP2进行的巢氏PCR,可检测到30fg基因组DNA,其灵敏度较常规PCR提高了1 000倍。利用巢氏PCR检测体系对发病程度不同的组织和携菌组织进行检测,均能快速稳定地检测出寄生隐丛赤壳菌。  相似文献   

6.
The origins of invasive weed populations can involve multiple species, introductions and genotypes. In California, USA, self-incompatible (SI) Lolium species are highly successful agricultural weeds. During the last decade, resistance to glyphosate has evolved in California populations of Lolium . However, the species identity of glyphosate-resistant populations is unclear. Occurrence of three SI species, L. multiflorum , L. rigidum and L. perenne , and the lack of reproductive barriers between them, suggests that any or all species may be contributing to resistant populations. To elucidate the identity and evolutionary history of resistant Lolium , we assessed genetic variation of known species and unknown California individuals using five simple sequence repeat loci, a nuclear DNA sequence and a chloroplast DNA sequence. Employing two analytical approaches, we identified three major genetic groups within the accessions of SI species that were similar, but not identical, to the taxonomic species identities. California glyphosate-resistant and susceptible plants were most closely related to the L. multiflorum group. However, a few glyphosate-resistant plants and a third of the glyphosate-susceptible plants also identified with L. rigidum and L. perenne . While L. rigidum and L. perenne contribute to invasive populations within California, the majority of glyphosate-resistant individuals tested were L. multiflorum .  相似文献   

7.
The genetic relationship between the vegetative compatibility groups (VCGs) and between physiological races of Fusarium oxysporum f. sp. lactucae (FOL), the causal pathogen of lettuce root rot, was determined by analyzing the intergenic spacer (IGS) region of its ribosomal DNA. A total of 29 isolates containing a type strain were tested: 24 Japanese isolates, 2 Californian isolates, and 3 Italian isolates. Three races (races 1, 2, and 3) were found in Japan, and race 1 was also distributed in California and Italy. Races 1, 2, and 3 each belonged to a distinct VCG: VCG-1, VCG-2, and VCG-3 (VCG-3-1, VCG-3-3), respectively. Phylogenetic (neighbor-joining) analysis of the IGS sequences revealed that races 1, 2, and 3 coincided with three phylogenetic groups (PG): PG-1, PG-2, and PG-3, respectively. These results indicate that the three races are genetically quite different and have a strong correlation with VCGs and phylogenetic groupings. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under the accession no. AB195218  相似文献   

8.
提取青藏高原环湖地区扁穗冰草35个样品的DNA,采用PCR产物直接测序的方法,对扁穗冰草rDNA的ITS区(包括ITS-4和ITS-5)进行序列测定.结果表明:扁穗冰草ITS序列总长度为649bp,其中有17个变异位点,扁穗冰草物种水平的Hd、Pi分别为0.916和0.00320,表明扁穗冰草物种水平上的遗传多样性相对较高.AMOVA分析表明,扁穗冰草大部分的遗传变异发生在居群内(77.62%),在系统发育树中,虽然4个地区样品聚为3支,但是每一支中不同地区的个体混杂在一起.  相似文献   

9.
Serious outbreaks of grapevine crown gall disease were observed in major Serbian viticultural regions during the last five years. Tumorigenic Agrobacterium vitis was identified as a causal agent by using conventional bacteriological and molecular tests. The 36 studied strains of A. vitis showed homogeneous biochemical and physiological characteristics, but were heterogeneous in their pathogenic properties, especially on tomato and sunflower. Furthermore, genetic differences related to chromosomal and plasmid DNA were observed. The Ti plasmid of 35 strains was classified as the octopine/cucumopine (O/C) type, whereas one was classified as the vitopine (V) type. The O/C strains were further divided into O/C-1 and O/C-2 groups based on PCR analysis. Moreover, the sequence analysis of the 16S-23S rRNA ITS region provided robust and precise delineation of studied strains. Although a high level of genetic diversity in A. vitis strains from Serbia was revealed by using this approach, their genotypic relatedness with the strains from other countries suggested their common origin. Also, association between the chromosomal and plasmid DNA was determined for some phylogenetic groups and clusters.  相似文献   

10.
The nrDNA internal transcribed spacer (ITS) and cpDNA trnL-F internal spacer (IGS) sequence data of Caragana eight species and one outgroup Halimodendron halodendron, was employed to reconstruct a phylogenetic tree, then the area relationship was analyzed by means of component analysis (CA), Brooks parsimony analysis (BPA), and dispersal-vicariance analysis (DIVA), six areas were selected from two divided distributions of East Asia and Tethys in Caragana. The phylogenetic tree indicated that there were three distinctive groups, which were attributed to some morphological characters, first with pinnate foliage and deciduous rachis, second with palmate foliage and persistent sclerotic stick rachis, and third with pinnate foliage and persistent sclerotic stick rachis. The results of CA and BPA illustrated general area relationships. An explicit area relationship should be Altai-Sayan, Far East-NE China and North China (Hengduan Mountains). DIVA recognized several explanatory vicariance and dispersal events. As the scenario of Caragana distribution pattern, it looks like the vicariance versus dispersal plays more important role. In vicaraince, there are not only the isolated far-distance vicariance, but also the adjacent vicariance especially a vicariance between Hengduan Mountains and North China.  相似文献   

11.
The rDNA-ITS sequence of Rhizoctonia solani AG 1-ID was determined and compared to those of R. solani AG 1-IA, AG 1-IB, and AG 1-IC. The similarity of the isolates from each AG 1 subgroup was almost identical (99%–100%), whereas it was lower between subgroups (91%–95%) than within subgroups. Phylogenetic analysis indicated that isolates of AG 1-ID and other subgroups were separately clustered. Isolates of R. solani AG 1 were clearly separated from R. solani AG 2-1, AG 4, and binucleate Rhizoctonia AG-Bb and AG-K. These results showed that analysis of the rDNA-ITS sequence is an optimal criterion for differentiating R. solani AG 1-ID from other subgroups of R. solani AG 1.  相似文献   

12.
Several published polymerase chain reaction (PCR) primers to identify Pseudomonas syringae pv. actinidiae, the causal organism of bacterial canker of kiwifruit, were found not to be specific. Two new sets of PCR primers, PsaF1/R2 and PsaF3/R4, were designed to be complementary to a portion of the 16S–23S rDNA intertranscribed spacer (ITS) regions. These primers amplified a DNA fragment from strains of P. syringae pv. actinidiae, but not from 56 strains of bacteria from six genera and 17 species, except for a strain of the tea pathogen, P. syringae pv. theae. When tested against DNA extracted from a further 20 strains from Japan, Korea, Italy and the USA deposited in culture collections as P. syringae pv. actinidiae, all except six cultures produced the expected product of 280 bp with PsaF1/R2 and 175 bp with PsaF3/R4. Results of multilocus sequence analysis using five housekeeping genes (gyrB, acnB, rpoD, pgi and cts) showed that none of these six strains was phylogenetically similar to P. syringae pv. actinidiae. In contrast to the P. syringae pv. actinidiae type strain, these strains were positive in the determinative tests for ice nucleation and syringomycin production. It is suggested that these six strains were incorrectly identified as P. syringae pv. actinidiae. It was not possible to distinguish P. syringae pv. actinidiae from the phylogenetically similar P. syringae pv. theae using the ITS, gyrB, acnB, rpoD, pgi or cts gene regions to design PCR primers. Because P. syringae pv. theae is unlikely to be found on kiwifruit, primers PsaF1/R2 and PsaF3/R4 are recommended for screening bacteria isolated from kiwifruit tissue.  相似文献   

13.
Tomato bacterial canker and wilt disease caused by Clavibacter michiganensis subsp. michiganensis (Cmm) is among one of the major bacterial diseases associated with tomato (Solanum lycopersicum L.) in the western Mediterranean region of Turkey. A total of 118 Cmm isolates were obtained from the petiole and the main vein of leaves of different cultivars of diseased tomato plants, and these isolates were cultured in semiselective medium (mSCM). The identity of Cmm isolates was confirmed through gas chromatography-fatty acid methyl-esters (GC-FAME) analysis and polymerase chain reaction (PCR) using the primers, CMM5 and CMM6. The fatty acid analysis of all the Turkish isolates yielded major components that included anteisoheptadeconic acid (a15:0), palmitic acid (i16:0) and anteisoheptadeconic acid (a17:0); the analysis detected and categorized all the isolates into 10 different FAME groups. Among repetitive element sequence PCR (rep-PCR) analysis, Box primer yielded the most reproducible genomic profiles with band sizes that ranged from ~200 bp to 2 kb. The isolates were also separated into 12 groups by pulsed-field gel electrophoresis (PFGE) after digesting the total genomic DNA with SpeI, a rare cutting enzyme. The genome sizes of the different strains of Cmm were also determined after running unrestricted total genomic DNA, which yielded average values between 3.0 and 3.5 MB. All the Cmm isolates had pCM1 and pCM2 plasmids. This is the first report on the detailed characterization of the Cmm population in Turkey.  相似文献   

14.
Chrysoporthe cubensis is one of the most serious canker pathogens on commercially grown Eucalyptus species in the tropics and subtropics. During recent surveys for native hosts of C. cubensis in Colombia, fungi with fruiting structures similar to those of C. cubensis were found on native Miconia theaezans and Miconia rubiginosa , both members of the Melastomataceae. These fungi were identified based on morphology and DNA sequences of the ITS1/ITS2 region of the rDNA operon and the β-tubulin genes. The majority of isolates from M. theaezans and M. rubiginosa grouped together with South American C. cubensis isolates from Eucalyptus species and Syzygium aromaticum (clove). However, some of the isolates from M. theaezans grouped with isolates of Chrysoporthella hodgesiana , another anamorph species linked to Chrysoporthe , from Tibouchina spp. in Colombia. Pathogenicity of these fungi was assessed on various Melastomataceae. Miconia rubiginosa was more susceptible to infection by C. cubensis than two Eucalyptus clones . Isolates of C. cubensis and Chrysop. hodgesiana were mildly pathogenic on the various hosts included in the pathogenicity trials, and most pathogenic on Tibouchina urvilleana and Tibouchina lepidota .  相似文献   

15.
为了解不同寄主植物对亚洲玉米螟Ostrinia furnacalis(Guenée)寄主专化性及遗传多样性的影响,以东北地区取食4种寄主植物的亚洲玉米螟种群为研究对象,选取其线粒体COⅠ和COⅡ基因作为分子标记,通过序列比对分析,研究了亚洲玉米螟种群间的遗传多样性、基因流水平及分子变异。结果显示,亚洲玉米螟线粒体基因具有较丰富的遗传多态性;COⅠ和COⅡ基因总寄主植物种群Fu’s Fs检验结果分别为-1.82和-2.04,种群历史呈扩张趋势,基因流Nm分别为6.38和3.24,说明各种群间基因交流水平较高;遗传变异主要来自于种群内部;亚洲玉米螟的单倍型在BI树和NJ树上的分布拓扑结构与寄主植物间无对应关系。研究表明,取食不同寄主植物的亚洲玉米螟种群间的遗传多态性较高,基因交流频繁,且尚未发生遗传分化。  相似文献   

16.
荻草谷网蚜Sitobion miscanthi (Takahashi)(在中国长时间学名误用为麦长管蚜Sitobion avenae Fabricius)是我国小麦的主要害虫,为小麦蚜虫优势种。该蚜虫因繁殖速度快、发育历期短、适应能力强且能随着气流远距离迁飞等特性,对小麦安全生产构成严重威胁。目前关于蚜虫种群遗传结构的研究主要基于线粒体基因开展。然而,初级共生菌布赫纳氏菌Buchnera aphidicola几乎存在于所有蚜虫中,其在研究蚜虫种群遗传结构多样性方面的潜在作用报道很少。本研究基于前期收集的荻草谷网蚜6个不同地理种群(苏州、武汉、昆明、廊坊、泰安、银川),对其线粒体COⅠ基因与初级共生菌B.aphidicola的两个单拷贝基因gnd与trpA进行PCR扩增、测序和群体遗传结构分析。根据对3个遗传标记基因聚类分析,荻草谷网蚜6个不同地理种群分为3组,分别为银川种群、苏州种群和其他种群(COⅠ: FCT= 0.364 2,P <0.05;gnd:FCT= 0.403 3,P <0.05;trpA:FCT= 0.222 9,P <0.05),3组间存在显著的遗传差异。银川种群和泰安种群间有相同的稀有单倍型H8(trpA),苏州种群和武汉种群也有相同的稀有单倍型H2与H23 (COⅠ),3组之间仍存在基因交流。因此我们推测在4、5月份东南季风盛行的情况下,银川种群迁入了外来虫源。蚜虫线粒体基因和初级共生菌基因的遗传结构分析结果基本一致,表明共生菌基因在研究蚜虫种群遗传结构和多样性具有潜在应用意义。综上所述,基于线粒体和共生菌基因序列的荻草谷网蚜不同地理种群的遗传结构解析可为蚜虫的迁飞提供分子证据。  相似文献   

17.
18.
为明确本地油茶病虫害防治对象,于2012-2013年实地调查了南昌市郊梅岭山区油茶林(树龄15年)病虫害的种类、发生情况及危害特点,分析了害虫的组成结构。结果表明,在梅岭山区油茶上可见6种病害发生,主要种类包括茶藻斑病,其病原为寄生性红锈藻(Cephaleuros virescens Kunze);油茶煤污病,其病原为田中新煤炱菌[Neocapnodium tanakae(Shirai et Hara)Yamam];油茶白绢病,其病原为齐整小核菌(Sclerotium rolfsii Sacc.)和油茶炭疽病,其病原为胶孢炭疽菌[Colletotrichum gloeosporioides(Penz.)Sacc.],尤以前两种危害严重。采集到害虫60种,其中以八点广翅蜡蝉[Ricania speculum(Walker)]、红背安缘蝽[Anoplocnemis phasiana(Fabricius)]、茶白毒蛾[Arctornis alba(Bremer)]、山茶象(Curculio chinensis Chevrolat)和歧沟臀肖叶甲(Colaspoides diffinis Lefèvre)为优势种群。这些害虫隶属于4目33科,以鞘翅目(12科)为多,占害虫总科数的36.4%。  相似文献   

19.
20.
In 2002, a powdery mildew with catenate conidia lacking fibrosin bodies was found on cucumber in a greenhouse in Kanagawa Prefecture, Japan. Morphological observation revealed that the fungus belongs to Oidium subgenus Reticuloidium, anamorph of the genus Golovinomyces. Molecular phylogenetic analyses of the nucleotide sequences of the rDNA ITS regions and D1/D2 domains of the 28S rDNA indicated that the fungus belongs to the clade of G. orontii with other Golovinomyces fungi from a wide range of host plants, suggesting that the fungus was newly transported from abroad. Because there has been no prior report of cucumber powdery mildew caused by Reticuloidium, further research on the physiology, epidemiology, control and resistant cucumber varieties is required.  相似文献   

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