共查询到20条相似文献,搜索用时 10 毫秒
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Fabiana Guzmán Fabián Giolitti Franco Fernández Claudia Nome Sergio Lenardon Luis Conci 《European journal of plant pathology / European Foundation for Plant Pathology》2014,138(4):679-683
Sunflower (Helianthus annuus L.) plants showing capitulum with virescence, phyllody and flower malformation, shortened internodes and abnormal branches were found in a field in Pedro Luro (Buenos Aires province, Argentina). Pleomorphic bodies resembling phytoplasmas were observed in sieve tube elements of symptomatic plants but not in healthy ones. DNA from all symptomatic sunflower plants analysed yielded, in direct PCR with phytoplasma universal primers P1/P7 and R16F2n/R2, fragments of expected size 1.8 kb and 1.2 kb, respectively. The phytoplasma associated with the disease, was named Sunflower Phyllody (SunPhy). Real and putative RFLP of the 16S rDNA showed the affiliation of SunPhy to 16SrIII (X-disease group), subgroup J. The 16S rDNA sequence from SunPhy showed the highest identity (99 %) with 16SrIII members and the phylogenetic tree confirmed a closer relationship to subgroup J of the 16SIII ribosomal group. This is the first report of a phytoplasma related to the 16SrIII group affecting sunflower. 相似文献
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M. S. Pallavi H. K. Ramappa K. S. Shankarappa K. T. Rangaswamy W. A. R. T. Wickramaarachchi M. N. Maruthi 《Phytoparasitica》2012,40(3):279-286
Chickpea (Cicer arietinum L.) plants showing typical symptoms of infection by a phytoplasma that causes phyllody disease have been commonly observed in recent years in parts of south India. The symptoms included pale green leaves, bushy appearance due to excessive stunting of shoots, reduced internodal length and excessive axillary proliferation. The causal agent of the phyllody disease was identified based on symptoms, amplification of 16S rDNA of the phytoplasma by polymerase chain reaction (PCR) from infected samples, as well as by sequencing and phylogenetic analysis. First round PCR and nested-PCR protocols were standardized for improved efficiency and reliability of the diagnostic protocols. Using the primers P1/P7 and R16F2n/R16R2, 1,800?bp and 1,200?bp size products were amplified in first round PCR and nested-PCR protocols, respectively. The PCR product was cloned and sequenced and compared with the reference phytoplasma sequences from the database (NCBI). The Indian chickpea phyllody phytoplasma 16S rDNA sequences shared the highest nucleotide identity (>98%) with the 16S rII group phytoplasma candidates, also infecting chickpea from Australia and Pakistan. This is the first report of a phytoplasma of the 16SrII-group infecting chickpea from India. The genetic similarities and the potential threat of this new disease to chickpea cultivation in India are discussed. 相似文献
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Since the 1980s a new disease has been affecting Australian lychee. Pepper spot appears as small, black superficial lesions on fruit, leaves, petioles and pedicels and is caused by Colletotrichum gloeosporioides, the same fungus that causes postharvest anthracnose of lychee fruit. The aim of this study was to determine if a new genotype of C. gloeosporioides is responsible for the pepper spot symptom. Morphological assessments, arbitrarily‐primed PCR (ap‐PCR) and DNA sequencing studies did not differentiate isolates of C. gloeosporioides from anthracnose and pepper spot lesions. The ap‐PCR identified 21 different genotypes of C. gloeosporioides, three of which were predominant. A specific genotype identified using ap‐PCR was associated with the production of the teleomorph in culture. Analysis of sequence data of ITS and β‐tubulin regions of representative isolates did not group the lychee isolates into a monophyletic clade; however, given the majority of the isolates were from one of three genotypes found using ap‐PCR, the possibility of a lychee specific group of C. gloeosporioides is discussed. 相似文献
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Panda Priyam Debnath Prasenjit Mall Smriti Nigam Amrita Rao Govind Pratap 《European journal of plant pathology / European Foundation for Plant Pathology》2021,161(2):313-330
European Journal of Plant Pathology - During the winters of 2018 to 2020, witches’ broom, phyllody, flat stem, little leaf, yellowing and stunting symptoms were recorded in Mexican... 相似文献
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2008年在杨凌采集到具有典型植原体侵染症状的菲白竹,应用植原体16S rRNA基因的通用引物对R16mF2/R16mR1和R16F2n/R16R2对其进行检测,巢式PCR得到约1.2 kb的特异性片段。对扩增片段进行测序并进行系统进化树分析,结果表明,该病原属于翠菊黄化组(Candidatus Phytoplasma asteris),与该组成员同源性均在98%以上。随后用16Sr Ⅰ组和Ⅴ组特异引物对R16(Ⅰ)F1/R16(Ⅰ)R1和R16(Ⅴ)F1/R16(Ⅴ)R1也证明其属于翠菊黄化组,RFLP 分析表明该植原体属于16SrⅠ-B亚组。植原体侵染菲白竹在中国属首次报道。 相似文献
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Journal of Plant Diseases and Protection - The phytophagous mite, Aceria litchii (Keifer), is one of the major pests of litchi (Litchi chinensis Sonn.) in Asia and Australia. By sucking on the... 相似文献
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I.-M. Lee M. Pastore M. Vibio A. Danielli S. Attathom R.E. Davis A. Bertaccini 《European journal of plant pathology / European Foundation for Plant Pathology》1997,103(3):251-254
A phytoplasma was detected in annual blue grass (Poa annua L. Fienardo), exhibiting white leaf symptoms, that was grown in the fields near Caserta in southern Italy. Based on restriction fragment length polymorphism analysis of PCR-amplified 16S rDNA sequences, the phytoplasma associated with annual blue grass white leaf disease was identified as a new member of phytoplasma 16S rRNA group XI (16SrXI) (type strain, rice yellow dwarf phytoplasma). The annual blue grass white leaf phytoplasma is most closely related to Bermuda grass white leaf phytoplasma found in Asia. Annul blue grass white leaf and Bermuda grass white leaf phytoplasmas were designated as the third subgroup (16SrXI-C) of group XI. This is the first report that a plant pathogenic phytoplasma belonging to group 16SrXI is present on the European continent. 相似文献
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Govind Pratap Rao Madhupriya Ajay Kumar Tiwari Shailendra Kumar Virendra Kumar Baranwal 《Phytoparasitica》2014,42(3):349-354
During a survey of sugarcane fields at the Sugarcane Research Institute, Shahjahanpur, Uttar Pradesh, India, in August–September 2012, 6% to 28% incidence of sugarcane grassy shoot disease was observed in different fields of sugarcane variety CoS 7250. The association of phytoplasma with symptomatic sugarcane was confirmed by direct and nested PCR amplification of phytoplasma ribosomal gene. Four different delphacid leafhopper species, viz. Cofana unimaculata Signoret, Exitianus indicus (Distant), Sogatella kolophon Kirkaldy and Hishimonus phycitis (Dist.) were the prevalent feeding species of the Auchenorrhyncha fauna in the symptomatic sugarcane fields. Out of these four leafhopper species, only E. indicus tested positive for phytoplasma presence. Phylogenetic analysis suggested that the phytoplasmas from sugarcane and E. indicus in the present study were members of 16Sr XI. The confirmation of association of sugarcane grassy shoot phytoplasma in E. indicus population is important to understand the secondary spread of this phytoplasma in sugarcane plants. 相似文献
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小麦蓝矮病植原体16S rDNA序列分析研究 总被引:2,自引:3,他引:2
小麦蓝矮病是我国西北地区冬小麦上一种重要病害。本研究利用植原体16S rDNA通用引物对小麦蓝矮病患病植株全DNA进行nest-PCR扩增,获得1.2 kb的特异片段,并对扩增产物进行核苷酸序列测定,从分子水平证明了小麦蓝矮病的病原是植原体。利用最大简约法构建了16S rDNA系统演化树,系统演化关系分析表明:小麦蓝矮病植原体应该归属于翠菊植原体(Candidatus Phytoplasma asteris);小麦蓝矮病植原体与三叶草变叶病植原体(CPh)关系密切,被聚类为同一亚组(16Sr I-C),但是它们在寄主范围和传播介体等生物学性状方面差异很大。 相似文献
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Jujube witches' broom (JWB) is a destructive disease for Chinese jujube caused by phytoplasma. A suppression subtractive hybridization library of resistant cultivar ‘Xingguang’ was constructed under phytoplasma stress to identify genes related to JWB resistance. 77 of 200 unique expressed sequence tags had significant sequence homologies and were classified into 10 functional groups. The most abundant group was disease/defense (20.8%), which was consistent with the phytoplasma stress. These differentially expressed genes provide the groundwork for addressing the plant–phytoplasma interaction. Meanwhile, the expression of five selected genes (TLP, PR10, HSP70, ERF, kinase-related protein) was confirmed to upregulate at different infection periods. 相似文献
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Ernestina Galdeano Fabiana Aída Guzmán Franco Fernández Luis Rogelio Conci 《European journal of plant pathology / European Foundation for Plant Pathology》2013,137(4):753-764
Twelve Argentinean 16SrIII (X-disease)-group phytoplasma strains were analyzed. Ten of them, detected in daisy (Bellis perennis), garlic (Allium sativum), ‘lagaña de perro’ (Caesalpinia gilliesii), periwinkle (Catharanthus roseus), ‘rama negra’ (Conyza bonariensis), ‘romerillo’ (Heterothalamus alienus), summer squash (Cucurbita maxima var. zapallito) and tomato (Solanum lycopersicum), are new phytoplasma strains while two strains, detected in garlic and China tree (Melia azedarach), have been previously described. The plants showed typical symptoms of phytoplasma diseases, such as leaf size reduction, proliferation, stunting and virescence. The identification and genetic diversity analysis of the phytoplasmas were performed based on 16S rDNA and ribosomal protein gene sequences. The classification into 16Sr groups and subgroups was established by actual and virtual RFLP analysis of the PCR products (R16F2/R16R2) compared with reference strains. According to the classification scheme, strains HetLL and ConWB-A and B represent two new subgroups 16SrIII-W and X, respectively. On the other hand, strains CatLL, TomLL and CaesLL are related to subgroup 16SrIII-B, and strains BellVir, TomRed, CucVir and GDIII-207 are related to subgroup 16SrIII-J. Ribosomal protein genes were amplified using primers rpF1/rpR1 and rpIIIF1/rpIIIR1. RFLP analysis performed with AluI, DraI and Tru1I (MseI isoschizomer) distinguished three new rp profiles within subgroup 16SrIII-B, one for subgroup 16SrIII-J, and one shared with strains of the new subgroups 16SrIII-W and X. The phylogenetic analysis based on 16S rDNA and ribosomal protein gene sequences confirmed the separation of HetLL and ConWB strains in two new subgroups and the close relatedness among subgroup J phytoplasmas, which have been detected only in South America. 相似文献
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M. C. C. Rappussi B. Eckstein D. Fl?res I. C. R. Haas L. Amorim I. P. Bedendo 《European journal of plant pathology / European Foundation for Plant Pathology》2012,133(4):829-840
Since 2000, a disease has occurred with high levels of incidence in crops of cauliflower grown in the green belt area of the city of S?o Paulo, Brazil. The symptoms are characterized by stunting, malformation of the inflorescence, reddening leaves, and vascular necrosis, suggesting infection by phytoplasma. These symptoms are similar to those described in Brassicas species affected by the aster yellows (16SrI) group of phytoplasma. In the present study, a phytoplasma from the 16SrIII-J subgroup was identified in cauliflower plants based on actual and virtual RFLP patterns and phylogenetic analysis, and was distinct from the phytoplasmas frequently associated with aster yellows disease in Brassicas. Pathogenicity assays using dodder confirmed that the identified phytoplasma is the agent of the observed disease, which is here designated as cauliflower stunt. Consequently, this species of Brassica may be recognized as a new host for subgroup 16SrIII-J, which has frequently been found in diverse species cultivated in Brazil. The spatial pattern of diseased plants was determined in ten cauliflower plots of 300 to 728 plants each. All plants in these plots were evaluated by visual assessments, assigned as diseased or healthy and mapped. The dispersion index and Taylor’s power law were determined for various quadrat sizes and the results showed that the diseased plants were distributed in a random pattern in fields with a low disease incidence and in an aggregated pattern in fields with a disease incidence greater than 25?%. According to an isopath area analysis, diseased plants were predominantly present in the field borders, suggesting that the pathogen is possibly introduced by vector(s) from the external area. 相似文献
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海南长春花黄化病植原体的16S rDNA序列分析研究 总被引:3,自引:0,他引:3
Periwinkle(Catharanthus roseus) yellows is a common disease in Hainan. Periwinkle's leaf tissue with symptoms was assayed for phytoplasma infection by using PCR assay employing phytoplasma universal 16S rRNA gene primers (Rl6mF2/Rl6mR1). A PCR product (about 1.4 kb) was amplified from periwinkle showed yellows. Nucleotide sequencing and phylogenetic tree analysis showed that the amplified 16S rDNA contained 1 432 nucleotides, the most homology was 98.1% with the members of elm yellows group (16S r Ⅴ) and clustered in the same clade, while it was under 96.1% with other phytoplasma groups. Our results suggested that the phytoplasma sample belonged to 16S rⅤgroup and was tentatively named as Hainan periwinkle yellows phytoplasma (PY-Hn). This is the first report of existence of 16S r Ⅴ group phytoplasma in naturally infected periwinkle. 相似文献