A new rhabdovirus found in Jasminum sambac and survey for possible insect vectors in Italy

In Spring 2023, a plant of Jasminum sambac showing virus-like symptoms consisting of bright yellow mosaic and deformation of the leaves was noticed in a nursery located in the Latium region. Similar symptoms were noticed again in Spring 2024 on another plant of J. sambac in the same nursery. Leaf samples collected from the plant identified in 2023 were subjected to high-throughput sequencing (HTS) of ribodepleted total RNAs. The results indicate that this plant was infected by two viruses: jasminum virus H and a new tentative rhabdovirus. Near complete genomes were assembled de novo for both viruses. The new rhabdovirus was also detected by RT-PCR, using specific primers designed on the sequence obtained by HTS, in the plant sampled in Spring 2024. Sanger sequencing confirmed amplicons specificity. Following the ICTV rules for the nomenclature of viruses, this new virus species has been tentatively named Alphanucleorhabdovirus jasmini. Possible insect vectors were identified by collecting specimens from several species of Jasminum, including J. sambac. In particular, two species of leafhopper were identified by morphological analysis and molecular characterization of the partial cytochrome oxidase gene (COI), as Hishimonus diffractus and Synophropsis lauri. These two species are under evaluation as potential vectors of the new rhabdovirus. The presence of infected plants coming from nurseries represents a serious problem for the spread of diseases, especially for new, incompletely characterized diseases. This situation requires more stringent controls that only the application of diagnostic systems such as HTS can guarantee.