22 research outputs found
Candidatus Phytoplasma brasiliense associado ao superbrotamento do hibisco (Hibiscus rosa-sinensis L.) no Estado de São Paulo
Grupo genético e heterose na produção de leite de vacas de corte submetidas a diferentes sistemas de alimentação
Erigeron (Conyza) bonariensis, a host of \u2018Candidatus Phytoplasma fraxini\u2019-related strain in Brazil
Erigeron bonariensis, the flax-leaved fleabane is found in several regions of Brazil. In the State of Rio de Janeiro, plants of E. bonariensis exhibiting shortened internodes, reduced leaf size, witches\u2019 broom and yellowing were tested for phytoplasma presence. Amplicons were obtained from nested PCR with primers designed for 16S rRNA and tuf genes. RFLP analyses of the ribosomal DNA revealed similarity to phytoplasmas of the ash yellows group and sequence analyses demonstrated 100% identity with phytoplasma strains belonging to subgroup 16SrVII-B from Argentina and Brazil. The sequence from tuf gene showed a maximum of 94% identity with \u2018Candidatus Phytoplasma fraxini\u2019 strain ASY3, and 92% identity with other strains of the ash yellows group. To our knowledge, this is the first report of the species Erigeron bonariensis harboring a \u2018Ca. P. fraxini\u2019-related strain in Brazil
Molecular characterisation of phytoplasmas infecting Dimorphandra spp. in Brazil
Dimorphandra sp., known as “fava d’anta” and “faveiro”, is an endemic species in several South American countries.
Symptomatic trees, with witches’ broom growths and other symptoms characteristic of diseases associated with
phytoplasma presence, were found harbouring phytoplasmas showing differences from those reported so far in Brazil.
Ribosomal gene sequencing of one of these strains indicated that it shared 99% of its identity with phytoplasmas enclosed in 16SrXIII group, detected in Mexico, Argentina and Bolivia. RFLP analyses on the ribosomal gene, and further characterisation of the rp gene, also showed the similarity of these with phytoplasmas detected in Turnera sp. in Brazil
Lagenaria siceraria yellows associated with phytoplasma presence in Brazil
Lagenaria siceraria, the bottle gourd or calabash gourd, is distributed in Brazil and locally known as “porongo”. It is used as a green vegetable and some cultivars are marketed as handicraft. In the State of Rio de Janeiro, naturally diseased plants were observed with reduced leaf size, leaf malformation and yellowing. Molecular analysis revealed the presence of a phytoplasma related to ‘Candidatus Phytoplasma pruni’ that was classified as a new subgroup -Y into the 16SrIII ribosomal group. This is the first report of the genus Lagenaria harbouring a phytoplasma worldwide
Hibiscus witches\u2019 broom disease associated with different phytoplasma taxa in Brazil
Stolbur group phytoplasmas were detected in symptomatic hibiscus plants from Brazil showing witches\u2019 broom symptoms while in other symptomatic samples of the same locations \u2018Candidatus Phytoplasma brasiliense\u2019 was identified. This finding confirms that diverse phytoplasmas can be associated with this disease in hibiscus. This is the first report of identification of a 16SrXII phytoplasma in this genus worldwide
Multigene characterization of phytoplasmas infecting Turnera ulmifolia in Brazil
Turnera ulmifolia, the yellow alder, is a widely distributed species in Brazil where, besides ornamental, it is used for its medicinal properties. Plants of T. ulmifolia exhibiting witches\u2019 broom growths and yellowing, that are symptoms typically associated with phytoplasma presence, have been observed in the location of Penedo, state of Rio de Janeiro. Symptomatic samples from T. ulmifolia were collected and after total nucleic acid extraction, universal primer pairs were used to prime amplification of phytoplasma 16S rDNA sequences, spacer region and beginning of the 23S rDNA. Expected length amplicons of 1.5 kb (F1/B6 primers) and 1.2 kb (R16F2/R2 primers) were obtained from all symptomatic samples tested after nested PCR on P1/P7 amplicons. RFLP analyses were carried out with Tru1I on F1/B6 and R16F2/R2 amplicons; and with TaqI, and AluI on R16F2/R2 amplicons. RFLP patterns were compared with those of phytoplasma reference strains on same size amplicons and allow to identify the detected phytoplasmas as belonging to ribosomal group 16SrXIII. Additional amplifications for molecular characterization of T. ulmifolia phytoplasmas, with primers rp(I)F1/rp(I)R1A amplifying rplV (rpl22) and rpsC (rps3) genes were then performed. The amplification of this gene resulted in the expected 1.2 kb amplicons and the RFLP profile obtained after Tru1I digestion was clearly different from any of those available in the literature for the same gene, indicating that this phytoplasma may represent a new strain in 16SrXIII group
Identidade molecular dos fitoplasmas associados aos enfezamentos do tomateiro e da berinjela com base na análise do gene 16S rDNA
Postprandial status and cardiovascular disease risk. Statement of position [Estado posprandial y riesgo de enfermedad cardiovascular. Declaratoria de posición]
[No abstract available