Citrus ophiovirus

Citrus ophiovirus (Ophiovirus citri) is a plant viral pathogen that affects various citrus species. Belonging to the genus Ophiovirus, this virus is characterized by a segmented negative-sense single-stranded RNA genome and causes systemic infection within the host plant, impacting its overall physiological health.

The host range primarily includes cultivated species of the genus Citrus, such as lemons and oranges. Because the virus inhabits the vascular system, it causes long-term structural and metabolic damage, significantly reducing the vigor and economic productivity of the affected trees.

Symptomatology involves distinct foliage patterns, including chlorotic spotting, mosaic-like patterns on young leaves, and occasional leaf curling or deformation. As the disease progresses, the tree may exhibit stunted growth, reduced canopy density, and decline, making the infection visible during intensive growth periods.

The transmission mechanism of Ophiovirus citri is unique, as it involves a soil-borne fungal vector, Olpidium brassicae. The zoospores of this fungus carry the virus and infect the roots of susceptible citrus plants, leading to localized soil-borne transmission patterns that are difficult to manage once established in a field.

Effective management relies entirely on prevention, as no chemical treatment can cure the viral infection once the host is systemically colonized. Agronomic strategies include:

• Utilizing certified virus-free rootstocks and nursery stock.
• Implementing strict quarantine measures for soil and plant material.
• Sterilizing greenhouse soils before new planting cycles.
• Monitoring potential fungal vector populations in the soil.