Rice virus disease caused by Fijivirus nilaparvatae

Fijivirus nilaparvatae is a viral pathogen classified within the Fijivirus genus of the Reoviridae family. It causes systemic infection in plants, affecting their vascular tissue and causing significant physiological stress that hinders normal development and grain maturation.

Rice (Oryza sativa) is the primary economic host for this virus. However, the virus also affects various wild grasses, which act as alternative hosts. These wild species are critical for the virus's overwintering strategy, ensuring that the pathogen remains present in the landscape from one planting season to the next.

The transmission is biological and persistent, primarily mediated by the brown planthopper (Nilaparvata lugens). Once an insect acquires the virus by feeding on an infected rice plant, it remains a vector for the duration of its life, effectively spreading the pathogen as it moves between plants during its feeding cycles.

Symptoms of the infection include severe plant stunting, dark green discoloration of the leaves, and the formation of characteristic galls or swellings on the veins of the leaves and stems. Infected plants typically fail to reach full maturity and produce deformed or empty panicles, leading to massive harvest failure.

Control strategies rely on a combination of host plant resistance and integrated pest management (IPM). Farmers should deploy appropriate insecticides to control planthopper populations, monitor fields for early signs of disease, and implement rigorous weed control measures to minimize reservoirs for the virus and its vectors.