RESUMO
La punta morada es una enfermedad que afecta la producción de algunas especies de solanáceas como la papa y el tomate, causando enrollamiento en las puntas de las hojas con una marcada coloración morada, decaimiento temprano de la planta y en la papa se observa tuberización aérea. Como patógenos asociados a la enfermedad se consideran al fitoplasma BLTVA y la bacteria Candidatus Liberibacter solanacearum. Dada la similitud en la sin-tomatología foliar que generan ambos patógenos, es difícil precisar cuál de ellos está implicado en la enfermedad. En Guatemala, existen reportes de la sintomatología típica de punta morada en las principales zonas productoras de papa y tomate, desconociéndose el agente asociado. La investigación determinó cuál de los dos patógenos reportados está asociados a la enfermedad en 12 municipios productores de papa y/o tomate en el país. Se realizaron ampli-ficaciones de ADN con cebadores específicos para cada patógeno asociado a la enfermedad. Por la alta incidencia del fitoplasma BLTVA en las muestras de papa (73.9%), en comparación a C. Liberibacter solanacearum (26%), este es considerado como el patógeno asociado más importante en papa. En las muestras de tomate, la incidencia del fitoplasma BLTVA (29.8%) y C. Liberibacter solanacearum del (27.6%) fue similar. Además, sobresale el primer reporte de la detección del fitoplasma BLTVA afectando el cultivo de tomate en Guatemala. Se sugiere un monitoreo constante, mediante métodos moleculares, para un diagnóstico certero y establecer medidas de manejo de la enfermedad para evitar su diseminación hacia zonas aún no afectadas.
The potato purple top is a disease that affects the production of some solanaceous species such as potatoes and tomatoes, causing curl at the tips of the leaves with a marked purple coloration, early decay of the plant, and aerial tuberization is observed in the potato. BLTVA phytoplasma and Candidatus Liberibacter solanacearum are considered as pathogens associated with the disease. Given the similarity in foliar symptoms generated by both pathogens, it is difficult to determine which one is involved in the disease. There are reports of the typical potato purple top symptoms in the main potato and tomato producing areas in Guatemala, being unknown the associated agent. The research determined which of the two reported pathogens is associated with the disease in 12 potatoes and/or tomato producing areas in the country. We performed DNA amplification with specific primers for each disease-associated pathogen. Due to the high incidence of BLTVA phytoplasma in potato samples (73.9%), com-pared to C. liberibacter solanacearum (26%), this is considered the most important associated pathogen in potatoes. In tomato samples, the incidence of BLTVA phytoplasma (29.8%) and C. liberibacter solanacearum (27.6%) was similar. Besides, the first report of the detection of the BLTVA phytoplasma affecting tomato cultivation in Gua-temala stands out. Using molecular methods, constant monitoring is suggested for an accurate diagnosis and to establish management measures for the disease to prevent its spread to areas not yet affected.
Assuntos
Solanum tuberosum/virologia , Solanaceae/virologia , Doenças por Fitoplasmas/microbiologia , Vírus de Plantas/isolamento & purificação , Produção Agrícola , DNA de Plantas/análise , Liberibacter/patogenicidadeRESUMO
Tomato severe rugose virus (ToSRV) is the most important begomovirus species in Brazilian tomato production. Many weeds are associated with tomato, and some are hosts of begomoviruses. Only one species of weed, Nicandra physaloides, has been found to be infected with ToSRV. In this study, four weed species were investigated for their capacity to be infected by ToSRV and serve as a potential source of inoculum for tomato. Begomoviruses from naturally infected Crotalaria spp., Euphorbia heterophylla, N. physaloides, and Sida spp. were successfully transferred to tomato plants by biolistic inoculation. ToSRV was the major virus transferred to tomato. In contrast, other begomoviruses were transferred to weeds, such as Sida micrantha mosaic virus and Euphorbia yellow mosaic virus. Furthermore, a new strain of Sida micrantha mosaic virus is reported. We also confirmed that Crotalaria spp., E. heterophylla, and Sida spp. are infected with ToSRV but at low viral titers and in mixed infections with weed-infecting begomoviruses. Thus, it was demonstrated that weeds are potential sources of ToSRV for tomato in central Brazil.
Assuntos
Begomovirus/isolamento & purificação , Crotalaria/virologia , Euphorbia/virologia , Malvaceae/virologia , Plantas Daninhas/virologia , Solanum lycopersicum/virologia , Sequência de Bases , Begomovirus/genética , Begomovirus/fisiologia , Brasil , Clonagem Molecular , Coinfecção , Primers do DNA/genética , DNA Viral/genética , Genoma Viral/genética , Dados de Sequência Molecular , Doenças das Plantas/virologia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNA , Solanaceae/virologia , Especificidade da EspécieRESUMO
Two virus isolates, T1 and T2, causing necrotic spots on leaves and stems of pepper and tomato, respectively, were isolated in the La Joya valley, Arequipa, Peru, in 2010. These two isolates were inoculated to differential hosts for tospoviruses and showed differential fitness: T1 induced necrotic local lesions in Vigna unguiculata, whereas T2 produced only chlorotic spots. The complete nucleotide sequence of the small (S) RNA from T2 and 1863 bp of the S RNA from T1 were determined. The deduced N protein sequence showed high amino acid identity (97%) between the isolates, indicating that the T1 and T2 are isolates of the same virus. Sequence comparisons indicated that the amino acid sequence of the N protein shared 53.49-87.98% identity with known American tospoviruses. Phylogenetic analysis of both the NSs and N proteins revealed that this new tospovirus belongs to the American group. We conclude that this tospovirus should be considered a member of a new species. The name Pepper necrotic spot virus (PNSV) is proposed.
Assuntos
Doenças das Plantas/virologia , Solanaceae/virologia , Tospovirus/classificação , Tospovirus/isolamento & purificação , Análise por Conglomerados , Genoma Viral , Especificidade de Hospedeiro , Dados de Sequência Molecular , Peru , Filogenia , RNA Viral/genética , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Tospovirus/genética , Tospovirus/patogenicidade , Proteínas Virais/genéticaRESUMO
Brugmansia suaveolens mottle virus (BsMoV) was the first potyvirus isolated from "angel trumpet" (Brugmansia suaveolens), described in Brazil. In this study, the complete nucleotide (nt) genome sequence of BsMoV was determined, and the deduced amino acid (aa) sequence was analyzed. The BsMoV RNA genome consists of 9870 nt without a poly-A tail, encoding a putative typical potyviral polyprotein of 3090 aa. Pairwise comparisons of the complete BsMoV genome with those of the most closely related potyviruses revealed a maximum nucleotide identity of 63.7% with pepper mottle virus. These results and phylogenetic analyses based on the complete genome sequence of the most closely related potyviruses confirmed that BsMoV should be considered a member of a distinct species of the genus Potyvirus.
Assuntos
Genoma Viral , Doenças das Plantas/virologia , Potyvirus/genética , RNA Viral/genética , Solanaceae/virologia , Brasil , Análise por Conglomerados , Dados de Sequência Molecular , Filogenia , Potyvirus/isolamento & purificação , Análise de Sequência de DNA , Homologia de Sequência do Ácido NucleicoRESUMO
A potyvirus was isolated from Brugmansia suaveolens showing leaf mottling and tentatively named Brugmansia suaveolens mottle virus (BsMoV). The virus (isolate Bs-Campinas) could infect some solanaceous plants and two Chenopodium species, and was transmitted by aphids. Symptomatic leaves contained flexuous particles and cylindrical inclusions. RT-PCR amplification using potyvirus universal primers produced a DNA fragment of 1851 nt (3' terminal genomic region), which shared 71% nucleotide identity with Pepper mottle virus, the best-matched potyvirus sequence. Since this identity value is below the threshold currently used to discriminate Potyvirus species, Brugmansia suaveolens mottle virus most likely represents a new Potyvirus species.
Assuntos
Doenças das Plantas/virologia , Potyvirus/classificação , Solanaceae/virologia , Animais , Afídeos/virologia , Brasil , Vetores de Doenças , Dados de Sequência Molecular , Folhas de Planta/virologia , Potyvirus/genética , Potyvirus/isolamento & purificação , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Homologia de Sequência do Ácido NucleicoRESUMO
Colombian datura virus (CDV) has been found to infect angel trumpets (Brugmansia spp.) frequently and cape gooseberry (Physalis peruviana) and pepino (Solanum muricatum) sporadically in Hungary. A CDV BRG/H isolate was characterized. It had flexuous thread-like virions of about 750 x 12 nm in size. Host range and symptomathological studies revealed its great similarity to authentic CDV isolates. Nicotiana tabacum cultivars and lines resistant to Potato virus Y (PVYN) either genically or transgenically proved highly susceptible to the BRG/H isolate. Tomato (L. esculentum cvs.) was systemically susceptible to this isolate, but some lines of Lycopersicon hirsutum and L. peruvianum turned out to be resistant. Browallia demissa, Ipomoea purpurea, N. megalosiphon and S. scabrum were demonstrated as new experimental hosts of CDV. The BRG/ H isolate proved to be transmissible by the aphid Myzus persicae Sulz. in a non-persistent manner. Potyvirus-specific coat protein (CP) gene sequences of about 1700 bp from angel trumpet, cape gooseberry and pepino plants were amplified by RT-PCR. The cloned BRG/H CP gene showed a 99.12-99.31% identity with other CDV isolates. CDV has been found for the first time to infect naturally cape gooseberry and pepino. Since the botanical genus name of original hosts of CDV has changed from Datura to Brugmansia, we propose to change the virus name from CDV to Angel trumpet mosaic virus (ATMV).
Assuntos
Potyvirus/isolamento & purificação , Solanaceae/virologia , Animais , Afídeos/virologia , Sequência de Bases , Proteínas do Capsídeo/genética , Genes Virais , Hungria , Hibridização Genética , Solanum lycopersicum/virologia , Dados de Sequência Molecular , Doenças das Plantas/virologia , Potyvirus/classificação , Potyvirus/genética , Potyvirus/ultraestrutura , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Terminologia como Assunto , Nicotiana/virologia , Vírion/ultraestruturaAssuntos
Países em Desenvolvimento , Doenças das Plantas/virologia , Vírus de Plantas , África/epidemiologia , Animais , Ásia/epidemiologia , Humanos , Incidência , Manihot/virologia , Oryza/virologia , Solanaceae/virologia , América do Sul/epidemiologia , Triticum/virologia , Zea mays/virologia , Zingiberales/virologiaRESUMO
A cDNA library was constructed from viral genomic RNA purified from sweet potato plants affected by "Sweet Potato Chlorotic Dwarf disease" in an attempt to clarify the etiology of this viral complex in Argentina. By sequence analysis, some of the obtained clones were found to belong to sweet potato feathery mottle potyvirus (SPFMV), to a closterovirus and to a new potyvirus. A cDNA clone of 1,103 bp representing the coat protein cistron and 3' non-coding region of the newly identified potyvirus was further characterized. The sequence contained an ORF of 855 nucleotides with a coding capacity of 285 amino acids, followed by a 3' untranslated tail of 248 nucleotides. The core and C-terminal regions have sequences well conserved among potyviruses. Furthermore, amino acid sequence comparisons of the capsid protein with those of other described potyviruses showed 63% homology with SPFMV, 68 to 70% with two different isolates of sweet potato latent potyvirus (SPLV), 57% with sweet potato G potyvirus (SPGV) and 73% with potato virus Y (PVY). These data allowed us to propose the inclusion of this virus as a new member of the family Potyviridae, genus Potyvirus with the designation sweet potato mild speckling potyvirus (SPMSV).