Symptomatic, widespread, and inconspicuous: new detection of tomato fruit blotch virus

Abstract

Tomato production is an important part of the Swiss vegetable production with most tomato crops grown in greenhouses. Tomato plants are vulnerable to diseases caused by viruses, which can have significant impacts on crop production. This study reports the first detection of tomato fruit botch virus (ToFBV, Blunervirus solani) in Switzerland, from a tomato production site at the southern part of the Ticino region. The symptoms observed indicated presence of a viral pathogen, but tests against the most common tomato viruses were negative. Immunocapture of double-stranded RNA and its subsequent sequencing on a Flongle flowcell (Oxford Nanopore Technologies) identified the presence of ToFBV and southern tomato virus. The genome of the Swiss ToFBV isolate was very similar to that available in GenBank. Datamining of the sequence read archives found the virus in two other countries, with a highly conserved genome. With this study, there are now 12 near-complete genomes of ToFBV available, and the virus is recorded from ten countries. This study underlines the importance of continuous monitoring and research on emerging viruses in tomato production.