Vernonia begomovirus

Begomovirus vernoniae is a plant-pathogenic virus belonging to the Geminiviridae family. It is characterized by a circular single-stranded DNA genome. The virus is primarily localized within the phloem tissues of infected plants, leading to systemic physiological disturbances and a significant decline in plant health.

The virus primarily affects plant species within the genus Vernonia, but its host range often extends to various weeds and related Asteraceae species in the field. These weed species act as crucial reservoirs, allowing the virus to persist in the environment between planting seasons and serving as primary infection points.

Symptoms of infection are usually systemic and include characteristic mosaic patterns, chlorotic mottling, leaf curling, and severe stunting. In advanced stages, the plants exhibit significant reduction in vegetative biomass and reproductive performance, as the virus severely disrupts the nutrient distribution within the host.

The transmission of Begomovirus vernoniae is mediated by insect vectors, most notably the whitefly species Bemisia tabaci. This insect acquires the virus during feeding and facilitates its spread across a field. The efficiency of transmission is dependent on the population density of the vector and the presence of susceptible plant material.

Preventive strategies and control measures are essential to manage this viral threat in agricultural and wild ecosystems:

• Strict management and removal of weed reservoirs around planting sites.
• Implementation of integrated pest management (IPM) to control whitefly populations.
• Utilization of certified virus-free seeds and planting material.
• Maintaining physical barriers such as insect-proof nets in nursery conditions.
• Rotation of crops to disrupt the life cycle of the vector and the virus.