Mimosa begomovirus

Pathogen and disease type. Mimosa begomovirus (Begomovirus mimosae) is a viral pathogen classified under the Begomovirus genus within the Geminiviridae family. These viruses are characterized by their monopartite or bipartite single-stranded DNA genome encased in geminate-shaped capsids. It is a systemic infection that interferes with the plant’s fundamental metabolic pathways, leading to chronic illness.

Host range and distribution. The primary hosts for this virus are various species within the Mimosa genus. The virus is predominantly found in tropical and subtropical climates, where environmental conditions support large populations of insect vectors. Increased international trade of botanical specimens has facilitated its spread into new geographical regions.

Symptoms and signs. Infected plants typically display mosaic patterns, chlorosis, and severe leaf deformation. The leaves may become wrinkled, puckered, or curled at the edges. Stunting is a common diagnostic sign, as the systemic infection significantly reduces the plant's ability to grow normally, often leading to a loss of vigor and distorted, unsightly plant architecture.

Development and impact. The virus is primarily transmitted by the whitefly Bemisia tabaci. When the insect feeds on the phloem sap of an infected plant, it acquires the virus and subsequently spreads it to healthy specimens. The economic impact is high, particularly for ornamental and nursery stock, as the infection is irreversible and renders plants unsuitable for commercial use.

Control and prevention. Since there is no cure for systemic plant viruses, management focuses on preventing the spread:

• Implementation of integrated pest management (IPM) to control whitefly populations.
• Sourcing only certified, virus-free propagative material.
• Rogueing: immediately removing and destroying infected plants to eliminate the source of inoculum.
• Sanitizing pruning tools regularly to prevent mechanical transmission.
• Establishing isolation zones between new plantings and areas with high virus pressure.