Molecular Characterization of a Novel Enamovirus Infecting Raspberry.

Raspberry plants, valued for their fruits, are vulnerable to a range of viruses that adversely affect their yield and quality. Utilizing high-throughput sequencing (HTS), we identified a novel virus, tentatively named raspberry enamovirus 1 (RaEV1), in three distinct raspberry plants. This study provides a comprehensive characterization of RaEV1, focusing on its genomic structure, phylogeny, and possible transmission routes. Analysis of nearly complete genomes from 14 RaEV1 isolates highlighted regions of variance, particularly marked by indel events. The evidence from phylogenetic and sequence analyses supports the classification of RaEV1 as a distinct species within the Enamovirus genus. Among the 289 plant and 168 invertebrate samples analyzed, RaEV1 was detected in 10.4% and 0.4%, respectively. Most detections occurred in plants that were also infected with other common raspberry viruses. The virus was present in both commercial and wild raspberries, indicating the potential of wild plants to act as viral reservoirs. Experiments involving aphids as potential vectors demonstrated their ability to acquire RaEV1 but not to successfully transmit it to plants.

Mixed Infection of Blackcurrant with a Novel Cytorhabdovirus and Black Currant-Associated Nucleorhabdovirus.

A virome screen was performed on a new breeding line, KB1, of blackcurrant. Rhabdovirus-like particles were observed by electron microscopy in ultrathin sections of flower stalks, and the complete genome sequence of a novel virus, provisionally named blackcurrant rhabdovirus 2 (BCRV2), was determined and verified using high-throughput sequencing. The genomic organization of BCRV2 was characteristic of cytorhabdoviruses (family Rhabdoviridae) and included seven genes: 3 ́- N-P´-P-P3-M-G-L -5 ́. BLASTP analysis revealed that the putative L protein had the highest amino acid sequence identity (75 %) with strawberry virus 2. BCRV2 was detected in Cryptomyzusgaleopsidis, but efficient transmission by this aphid was not confirmed. Of note, we observed coinfection of the KB1 line with blackcurrant-associated rhabdovirus (BCaRV) by RT-PCR. This is likely the first evidence of the presence of a cyto- and a nucleorhabdovirus in a single host.