Identification of Tomato mottle mosaic virus in historic seed accessions originating from France, the Netherlands and Spain, indicates a wider presence before its first description

Tomato mottle mosaic virus (ToMMV) is a tobamovirus found in a Solanum lycopersicum sample collected in Mexico in 2009. To assess the possible presence of ToMMV in Europe, accessions from a historic seed collection were tested by real-time RT-PCR and Illumina sequencing. ToMMV was identified in historical seed accessions produced in France, the Netherlands and Spain. Three different near complete genome sequences were obtained, each corresponding to the country in which the seeds had been produced. Positive samples from France and Spain could be related to the same production location and year, respectively, while the identical genome sequences from the Netherlands were obtained from samples produced in different locations and years between 1981 and 2007. The latter could be due to the fact that the Dutch seed accessions had been repacked in the past at the same location and time as accessions with a relatively high virus load from 2007. This indicates that possibly only the seeds from 2007 originated from ToMMV-infected plants, while the detection of ToMMV in the older seed accessions resulted from cross contamination. This data shows that ToMMV has been around in Europe before its first description and is possibly more widespread than currently known.