High-throughput sequencing (HTS) was employed for the first time to investigate plant viruses infecting solanaceous crops, including potato (Solanum tuberosum), tomato (Solanum lycopersicum), and pepper (Capsicum annuum), in Kosovo. Leaf samples showing virus-like symptoms were collected from various regions during the summer of 2023. Based on ribodepleted RNA sequencing and bioinformatics analysis, six viruses were identified: cucumber mosaic virus, broad bean wilt virus 2 (BBWV2), potato virus Y, pepper cryptic virus 2 (PCV2), bell pepper endornavirus (BPEV), and ranunculus white mottle virus. BBWV2, PCV2, and BPEV are reported for the first time in the Balkan region. Virus presence was validated using RT-PCR. Phylogenetic analyses revealed that the identified viral strains did not cluster according to their hosts and geographical origins. CMV and BBWV2 variants exhibited reassortment events, indicating possible local evolution or novel virus introductions. This research highlights the widespread occurrence of mixed infections in pepper plants and highlights the need for additional research into the virus transmission dynamics and potential reservoir hosts. These findings emphasize the need for continuous surveillance and integrated plant protection strategies to mitigate the impacts of viral infections on pepper and other economically important crops in Kosovo.

Weed control of solanaceous weeds growing with solanaceous crops is a constant challenge. Infected by viruses, they can also act as virus reservoirs, complicating this problem further. Viromes of annual Solanum nigrum, Datura stramonium, and Solanum dulcamara, a perennial climbing shrub, were investigated using RNA sequencing and validated using RT-PCR, revealing infection with nine viruses. Broad bean wilt virus 1 (BBWV1), cucumber mosaic virus (CMV), and potato virus M (PVM) were found to infect S. nigrum. Investigating only 46 plants revealed infection with Solanum dulcamara yellow fleck virus (SDYFV) not only in S. dulcamara but in a new host, D. stramonium, which also represents a new host of turnip yellows virus (TuYV). We described the first presence of a potato virus H (PVH)-like, and Oxybasis rubra mitovirus 1 (OxruMV1)-like virus in Europe, in S. dulcamara as a new host. Our results highlight the unexpected complexity of the viromes of solanaceous weeds, which should be considered during reliable and efficient plant protection strategies, in order to alleviate the virus reservoir role of the weeds.