Southern rice black-streaked dwarf virus

Southern rice black-streaked dwarf virus (SRBSDV) is a viral plant pathogen belonging to the genus Fijivirus within the family Reoviridae. This virus represents a significant threat to rice production in East and Southeast Asia, characterized by its ability to cause severe stunting and systemic infection in rice plants.

The host range of SRBSDV primarily includes Oryza sativa, though it also infects maize and various wild grasses. Infected plants exhibit distinct physiological changes, including severe dwarfism, dark green foliage, and the development of white or brown galls on the culms and leaf sheaths, which eventually turn black due to tissue necrosis.

The transmission of the virus is exclusively mediated by the white-backed planthopper, Sogatella furcifera. It is a persistent, circulative transmission process, meaning the insect acquires the virus after feeding on infected plant sap and retains the capacity to transmit it for the remainder of its lifespan, facilitating rapid spread across rice fields.

The environmental conditions favoring the prevalence of SRBSDV include warm temperatures and high humidity, which are ideal for the rapid development and migration of the Sogatella furcifera vector. Outbreaks are often linked to early-season migrations of the planthopper into newly planted rice fields, leading to widespread infection if the initial population is not adequately controlled.

Effective management and control strategies for SRBSDV focus on the following integrated practices:

• Deploying resistant rice cultivars to limit viral replication.
• Implementing chemical control of the planthopper population using systemic insecticides.
• Monitoring the flight patterns of Sogatella furcifera to time pesticide applications precisely.
• Reducing the virus reservoir by managing weeds in and around the paddy fields.
• Adjusting planting schedules to avoid peak migration periods of the vector.