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A novel nepovirus was identified and characterised from caraway, and tentatively named caraway yellows virus (CawYV). Tubular structures with isomeric virus particles typical for nepoviruses were observed in infected tissues by electron microscopy. The whole genome of CawYV was identified by high throughput sequencing (HTS). It consists of two segments with 8026 nt for RNA1 and 6405 nt for RNA2, excluding the poly(A) tails. CawYV-RNA1 shared closest nt identity to peach rosette mosaic virus (PRMV) with 63%, while RNA2 shared 41.5% with blueberry latent spherical virus (BLSV). The amino acid sequences of the CawYV protease-polymerase (Pro-Pol) and capsid protein (CP) regions share the highest identities with those of the subgroup C nepoviruses. The Pro-Pol region shared highest aa identity with PRMV (80.1%), while the CP region shared 39.6% to soybean latent spherical virus. Phylogenetic analysis of the CawYV-Pro-Pol and -CP aa sequences provided additional evidence of their association with nepoviruses subgroup C. Based on particle morphology, genomic organization and phylogenetic analyses, we propose CawYV as a novel species within the genus Nepovirus subgroup C.

A tenuivirus, referred to here as JKI 29327, was isolated from a black medic (Medicago lupulina) plant collected in Austria. The virus was mechanically transmitted to Nicotiana benthamiana, M. lupulina, M. sativa, Pisum sativum and Vicia faba. The complete genome was determined by high throughput sequencing. The genome of JKI 29327 consists of eight RNA segments closely related to those of melon chlorotic spot virus (MeCSV) isolate E11–018 from France. Since segments RNA 7 and 8 of JKI 29327 are shorter, its genome is slightly smaller (by 247 nts) than that of E11–018. Pairwise comparisons between the predicted virus proteins of JKI 29327 and their homologues in E11–018 showed aa identities ranging from 80.6 to 97.2%. Plants infected with E11–081 gave intermediate DAS-ELISA reactions with polyclonal antibodies to JKI 29327. Since JKI 29327 and E11–018 appear to be closely related both serologically and genetically, we propose to regard JKI 29327 as the black medic strain of MeCSV. To our knowledge, JKI 29327 represents the second tenuivirus identified from a dicotyledonous plant. Serological and molecular diagnostic methods were developed for future detection. [ABSTRACT FROM AUTHOR]