RESUMO
In recent years, the occurrence of cucumber mosaic virus (CMV) has been noted in zucchini crops in Poland. Beside characteristic isolates, which displayed mosaics and chlorosis on infected plants, new necrotic isolates have also been identified. Here, we analysed the molecular variability of 27 isolates of CMV collected from zucchini in various regions of the country. Sequence and phylogenetic analysis based on the genes encoding the coat (CP) and movement (MP) proteins revealed that the Polish isolates belong to two subgroups: IA and II, with the prevalence of subgroup II. New recombinant variants with an IA-MP/II-CP pattern for RNA3 were also detected.
Assuntos
Cucumovirus/genética , Cucumovirus/isolamento & purificação , Cucurbita/virologia , Variação Genética , Filogenia , Doenças das Plantas/virologia , Cucumovirus/classificação , Polônia , Recombinação Genética , Proteínas Virais/genéticaRESUMO
Tomato black ring virus (TBRV) infects a wide range of economically important plant species worldwide. In the present study we developed a locked nucleic acid (LNA) real-time RT-PCR assay for accurate detection of genetically diverse TBRV isolates collected from different hosts. The assay based on the LNA probe has a wide detection range, high sensitivity, stability and amplification efficiency. The assay amplified all tested TBRV isolates, but no signal was observed for the RNA from other nepoviruses and healthy plant species. Under optimum reaction conditions, the detection limit was estimated around 17 copies of the TBRV target region in total RNA. Real-time RT-PCR with the LNA probe described in this paper will serve as a valuable tool for robust, sensitive and reliable detection of TBRV isolates.
Assuntos
Nepovirus/classificação , Nepovirus/isolamento & purificação , Sondas de Oligonucleotídeos/genética , Solanum lycopersicum/virologia , Doenças das Plantas/virologia , RNA Viral/análise , Reação em Cadeia da Polimerase em Tempo Real/métodos , Sensibilidade e EspecificidadeRESUMO
The complete nucleotide sequence of a Polish isolate of Beet soil-borne virus was determined for the first time. The genome organization was identical with those previously established for isolates from Germany and China. A comparison of the Polish isolate with others deposited in GenBank revealed high level of nucleotide identity, about 98-100%, throughout the genome analyzed. The ratio between non-synonymous and synonymous substitutions was rather low suggesting a negative selective pressure. The non-synonymous mutations were particulary frequent in triple gene block.