First report of citrus bark cracking viroid and hop latent viroid in Brazil
In Brazil, cultivation of hop (Humulus lupulus) has been increasing during the past decades due to a large demand for craft beers. Studies on viroids were carried out in commercial hop gardens. From May 2020 to October 2021, samples were collected from several varieties of hop plants (cvs. Cascade, Comet, Saaz, Triple, Zeus) showing symptoms of dwarfism and yellowing in three Brazilian states (Minas Gerais, São Paulo and Paraná). Molecular tests (RT-PCR, sequencing, hybridization) confirmed the presence of viroids in some samples. 80% of the tested plants (all regions and varieties) were infected by hop latent viroid (HLVd – Cocadviroid). In samples of H. lupulus cv. Cascade and Comet from São Paulo, a co-infection by HLVd and citrus bark cracking viroid (CBCVd, Cocadviroid - EPPO A2 List) was detected. The Brazilian isolate of CBCVd shared 98% sequence identity with an isolate from China. The authors noted that this is the first time that both CBCVd and HLVd are detected in commercial hop gardens in Brazil, and that further studies are needed to better understand their incidence and impact.
The situation of citrus bark cracking viroid in Brazil can be described as follows: Present, not widely distributed.
Sources
Eiras M, de Oliveira AM, de Fátima Ramos A, Harakava R, Daròs JA (2023) First report of citrus bark cracking viroid and hop latent viroid infecting hop in commercial yards in Brazil. Journal of Plant Pathology 105, 603. https://doi.org/10.1007/s42161-023-01313-4