Sinaloa tomato leaf curl virus

The Sinaloa tomato leaf curl virus (STLCV) is a plant pathogenic virus belonging to the family Geminiviridae, genus Begomovirus. It contains a single-stranded circular DNA genome and relies entirely on insect vectors for dissemination.

As a begomovirus, it is restricted to the phloem tissue of the host plant. It does not spread through mechanical sap contact or contaminated seeds, making its epidemiology exclusively dependent on the presence and movement of its specific whitefly vector.

STLCV causes severe stunting and leaf deformation in Solanaceous crops, primarily tomatoes and peppers. It is considered a major limiting factor for tomato production in infested geographic areas, as it causes significant economic losses.

The virus affects the entire metabolism of the host plant. Infected plants show reduced fruit set, while those that do manage to bear fruit often produce small, chlorotic, or malformed produce, rendering them commercially unmarketable.

The transmission of the virus is synchronized with the activity of the whitefly Bemisia tabaci. The virus is acquired by the insect during feeding and can be transmitted to healthy plants after a short inoculation period.

Epidemics typically occur during periods of high temperature and high vector pressure. In protected cultivation systems, if the greenhouse is not adequately screened, the virus can spread rapidly throughout the entire growing season regardless of external weather conditions.

The most diagnostic sign of STLCV infection is the upward curling of the leaf margins, often accompanied by interveinal chlorosis. As the disease progresses, the plant exhibits severe stunting and shortened internodes.

The foliage often turns brittle and yellow, and the plant takes on a bushy, compact appearance due to the suppression of apical dominance. These symptoms can be easily confused with physiological disorders, making early molecular diagnostics crucial for confirmation.

Management of the virus is primarily focused on controlling the whitefly vector population. Because there is no direct chemical cure for the virus itself, prevention remains the most effective approach.

• Implementation of fine-mesh insect-proof screening in greenhouses.
• Application of systematic insecticides to reduce whitefly density.
• Removal of volunteer tomato plants and weeds that harbor the virus.
• Use of virus-resistant tomato cultivars developed through breeding programs.