First report of apium virus Y and carrot thin leaf virus in parsley in Slovenia.
Parsley plants (Petroselinum crispum) with disease symptoms were observed in a private garden in October 2014 and in a field used for commercial parsley production in September 2016 in central Slovenia. The plants showed symptoms of severe mosaic, distortion, and stunted growth. In the commercial field, up to 10% of parsley plants were symptomatic. Symptomatic plants were scattered throughout the field, with no apparent pattern. When the sap from two selected symptomatic plants (one from each location) was examined using transmission electron microscopy, filamentous virus particles of size 750 to 850 × 12 to 13 nm were observed. High-throughput sequencing, ELISA and reverse transcription polymerase chain reaction tests revealed two viruses, i.e. Apium virus Y (ApVY) and Carrot thin leaf virus (CTLV). This is thought to be the first report of ApVY and CTLV in Slovenia. Further investigations, carried out in 2016, revealed symptomless infections of parsleys by ApVY only (consensus genomic sequence deposited in GenBank, MH170888). The presence of ApVY in asymptomatic parsley plants has been observed also in California, USA.