Ophiovirus

Ophioviruses (genus Ophiovirus) are a group of plant-pathogenic viruses characterized by a segmented, negative-sense single-stranded RNA genome. These pathogens are known for their unique ability to cause systemic infections in a variety of horticultural and agricultural crops, often leading to significant losses in yield and product quality.

Key crops susceptible to Ophiovirus infection include lettuce, various bulbous ornamentals like lilies and tulips, as well as citrus trees. The host range varies between specific virus species, but the economic impact remains severe across all affected sectors, particularly in greenhouse-grown vegetables and commercial flower production.

Symptoms of Ophiovirus infection are diverse and often stage-dependent. Common signs include chlorotic ring spots, mosaic patterns, leaf deformation, stunting, and necrotic lesions. Because these symptoms can resemble other viral or fungal diseases, laboratory diagnosis is essential for accurate identification of the pathogen.

Transmission of Ophiovirus species is primarily facilitated by the soil-borne chytrid fungus Olpidium brassicae. The virus particles survive within the fungal zoospores, which move through water-saturated soil to infect the roots of host plants. Consequently, the prevalence of the virus is directly linked to soil moisture levels and the presence of the fungal vector.

Managing Ophiovirus requires an integrated approach due to the lack of curative treatments. Control strategies focus on:

• soil pasteurization or chemical fumigation to eliminate the fungal vector;
• using certified virus-free seed or planting material;
• implementing strict sanitation protocols in greenhouses;
• rotating crops to disrupt the life cycle of the vector.