Aster Yellows
Mostrando 1-12 de 13 artigos, teses e dissertações.
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1. Sesame phyllody associated with a 16SrI-B phytoplasma, a ‘Candidatus Phytoplasma asteris’-related strain, in Paraguay
ABSTRACT: Sesame (Sesamum indicum L.) plants exhibiting symptoms of phyllody disease were observed in commercial fields in Paraguay. The symptoms were indicative of infection by phytoplasmas. Thus, the present study investigated the association between affected plants and phytoplasma, which was later analyzed using molecular and phylogenetic methods. Total D
Sci. agric. (Piracicaba, Braz.). Publicado em: 2019-02
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2. Identificação molecular de um fitoplasma do grupo 16Srl-B em plantas de soja / Molecular identification of a group 16SrI-B phytoplasma in soybean plants
Plantas apresentando folhas com deformações do tipo bolhas, menor quantidade de vagens de tamanho reduzido e contendo menor número de sementes, vagens que não completaram a maturação e coloração verde da parte aérea no final do ciclo foram observadas em campos de produção. As plantas foram analisadas visando à detecção de fitoplasmas e a sua id
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/01/2012
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3. Evidence on Possible Mycoplasma Etiology of Aster Yellows Disease I. Suppression of Symptom Development in Plants by Antibiotics
Antibiotics suppressed development of aster yellows (AY) disease symptoms in plants of china aster [Callistephus chinensis (L.) Nees.] and annual chrysanthemum (Chrysanthemum carinatum, Schousb.). When inoculated chrysanthemum plants were treated by any of several techniques with tetracycline antibiotics or chloramphenicol, symptoms failed to appear during t
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4. Genetic Interrelatedness among Clover Proliferation Mycoplasmalike Organisms (MLOs) and Other MLOs Investigated by Nucleic Acid Hybridization and Restriction Fragment Length Polymorphism Analyses
DNA was isolated from clover proliferation (CP) mycoplasmalike organism (MLO)-diseased periwinkle plants (Catharanthus roseus (L.) G. Don.) and cloned into pSP6 plasmid vectors. CP MLO-specific recombinant DNA clones were biotin labeled and used as probes in dot hybridization and restriction fragment length polymorphism analyses to study the genetic interrel
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5. Identification and characterization of plasmids from the western aster yellows mycoplasmalike organism.
Supercoiled double-stranded DNA molecules (plasmids) were isolated from plants infected with three laboratory strains of western aster yellows mycoplasma-like organism (AY-MLO) by using cesium chloride-ethidium bromide density gradients. Southern blot analysis, using plasmids from the severe strain of AY-MLO (SAY-MLO) as the probe, identified at least four p
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6. Evidence on Possible Mycoplasma Etiology of Aster Yellows Disease II. Suppression of Aster Yellows in Insect Vectors
Chlortetracycline or chloramphenicol (but not kanamycin, penicillin, or erythromycin), when administered in hydroponic solution to diseased aster, reduced the availability of the aster yellows (AY) agent to nymphs of Macrosteles fascifrons (Stål). Insects exposed to healthy plants whose roots were immersed in chlortetracycline were able to acquire AY agent
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7. Mycoplasma-like bodies in the salivary glands of insect vectors carrying the aster yellows agent.
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8. Nonradioactive Screening Method for Isolation of Disease-Specific Probes To Diagnose Plant Diseases Caused by Mycoplasmalike Organisms
DNA fragments of tomato big bud (BB) mycoplasmalike organism (MLO) in diseased periwinkle plants (Catharanthus roseus L.) were cloned to pSP6 plasmid vectors and amplified in Escherichia coli JM83. A nonradioactive method was developed and used to screen for MLO-specific recombinants. Cloned DNA probes were prepared by nick translation of the MLO recombinant
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9. Enzymatic activities in cell fractions of mycoplasmalike organisms purified from aster yellows-infected plants.
Mycoplasmalike organisms (MLOs), purified from aster yellows-infected plants were osmotically lysed, and the membranes were separated from the cytoplasmic fraction through differential centrifugation. Electron microscopic examinations of sections of the purified MLOs and the isolated membranes showed pleomorphic bodies and unit membranous empty vesicles, res
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10. Presence of Two Sets of Ribosomal Genes in Phytopathogenic Mollicutes
DNA from 28 strains of phytopathogenic mycoplasmalike organisms that represented five primary taxonomic clusters was digested with restriction endonucleases and hybridized with several ribosomal probes. The results indicate the presence of two sets of ribosomal genes in all strains examined. Restriction maps of the two ribosomal operons for a group of 12 ast
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11. Sequence heterogeneity in the two 16S rRNA genes of Phormium yellow leaf phytoplasma.
Phormium yellow leaf (PYL) phytoplasma causes a lethal disease of the monocotyledon, New Zealand flax (Phormium tenax). The 16S rRNA genes of PYL phytoplasma were amplified from infected flax by PCR and cloned, and the nucleotide sequences were determined. DNA sequencing and Southern hybridization analysis of genomic DNA indicated the presence of two copies
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12. Phylogeny of mycoplasmalike organisms (phytoplasmas): a basis for their classification.
A global phylogenetic analysis using parsimony of 16S rRNA gene sequences from 46 mollicutes, 19 mycoplasmalike organisms (MLOs) (new trivial name, phytoplasmas), and several related bacteria placed the MLOs definitively among the members of the class Mollicutes and revealed that MLOs form a large discrete monophyletic clade, paraphyletic to the Acholeplasma