MODE OF TRANSMISSION OF PARIETARIA MOTTLE VIRUS

Parietaria mottle virus (PMoV) typically occurs at the edge of tomato and pepper crops in north-eastern Spain. Studies were conducted on PMoV transmission both by pollen and by seven insect species of the orders Hemiptera and Thysanoptera. The presence of PMoV was detected by indirect ELISA (I-ELISA) in symptomatic tomato and pepper plants collected from commercial fields. All weed species collected in the area surrounding these crops were symptomless. However, the virus was detected by I-ELISA in pollen extracts from Parietaria officinalis plants and transmitted mechanically to other species, including tomato and pepper. PMoV was transmitted to other hosts using several insect species and P. officinalis plants as a pollen source. Transmission was non-persistent, not very efficient, and it was rare if flowers of infected P. officinalis plants had previously been removed or when alternative hosts that produced smaller quantities of pollen were used. In addition, 36% of the seedlings derived from seed of infected P officinalis plants were shown to be infected with PMoV. Overall, our results suggest that eliminating PMoV-infected P. officinalis plants that surround tomato and pepper crops could help restraining virus spread.