Differently from Mexico and Colombia, CL caused by dichorhaviruses in Brazil has been reported only in marginal citrus-growing areas. The disease can be caused by viruses of at least five species within the genera Dichorhavirus and Cilevirus, but commercial orchards in Brazil are almost exclusively affected by citrus leprosis virus C ( Cilevirus leprosis, genus Cilevirus, family Kitaviridae). ĬL is considered the main viral disease that affects citrus production in Brazil. and the dichorhaviruses they transmit is often very strict, likely as a consequence of coevolution between them, as is suggested by phylogenetic data. The relationship between Brevipalpus spp. s.), and citrus chlorotic spot virus (CiCSV, Dichorhavirus citri), associated with B. However, the dichorhaviruses citrus leprosis virus N (CiLV-N, Dichorhavirus leprosis), transmitted by B. In Brazil, OFV has been found infecting orchids but not citrus, which is likely due to the absence of B. californicus to orchids and citrus, and it causes citrus leprosis (CL) disease in Mexico, Colombia, South Africa, and Hawaii (USA). Orchid fleck virus (OFV, Dichorhavirus orchidaceae) is transmitted by B. azores as a viral vector and supports the assignment of CiBSV to the tentative new species Dichorhavirus australis.ĭichorhaviruses are plant-to-plant transmitted by some species of flat mites of the genus Brevipalpus (Acari: Tenuipalpidae), where they can also replicate. The study provides the first evidence of the role of B. azores were found, but the virus could only be transmitted to Arabidopsis plants by B. Phylogenetically, the three haplotypes of the new virus called citrus bright spot virus (CiBSV) are clustered with citrus leprosis virus N, which is a dichorhavirus transmitted by Brevipalpus phoenicis sensu stricto. These genomes shared 98–99% nt sequence identity among them but <73% with those of known dichorhavirids, a value below the threshold for new species demarcation within that genus. The genomes of bi-segmented ss(−)RNA viruses, with ORFs in a typical organization of members of the genus Dichorhavirus, were recovered. RNA extracts from three plants, which proved negative by RT-PCR for known CL-causing viruses, were analyzed by high throughput sequencing and Sanger sequencing after RT-PCR. Rod-like particles of 40 × 100 nm and electron lucent viroplasm were observed in the nucleus of infected cells in symptomatic tissues. Osbeck) trees affected by CL were identified in small orchards in Southern Brazil. Citrus leprosis (CL) is the main viral disease affecting the Brazilian citriculture.
0 Comments
Leave a Reply. |