Spilanthes begomovirus

Spilanthes begomovirus (Begomovirus spilanthis) is a significant viral pathogen causing severe diseases in various plant species, particularly within the Acmella genus. As a member of the Geminiviridae family, this virus utilizes a circular single-stranded DNA genome to replicate within the host, leading to systemic infection that disrupts the plant's normal growth patterns.

The primary host for this pathogen is Spilanthes (Acmella oleracea), which is economically valuable for its medicinal properties. The virus attacks the phloem tissue, effectively compromising the plant’s ability to transport nutrients. This disruption directly impacts the chemical composition and overall biomass production of the crop.

Symptoms of the infection manifest primarily as foliar mosaic patterns, yellowing (chlorosis), and significant leaf curling. In advanced stages, infected plants exhibit stunted development, reduced flowering, and overall loss of vigor. These symptoms are often easily confused with nutrient deficiencies, which may delay necessary intervention.

Transmission occurs exclusively through insect vectors, most notably the whitefly (Bemisia tabaci). The virus is acquired by the insect through feeding on infected sap and is subsequently transmitted to healthy plants. Outbreaks are highly correlated with warm, humid weather conditions that promote rapid reproduction cycles of the whitefly population.

Effective management and prevention strategies are essential to maintain crop productivity:

• Implement a strict integrated pest management (IPM) program targeting whitefly populations.
• Use virus-free planting material to prevent initial entry into the field.
• Maintain a weed-free environment around the fields to eliminate potential reservoirs.
• Utilize physical barriers like insect-proof netting in greenhouse or high-tunnel conditions.
• Adopt resistant cultivars if they become available through breeding programs.