Rosellinia necatrix betapartitivirus

Betapartitivirus roselliniae is a species of mycovirus belonging to the Partitiviridae family. It primarily infects Rosellinia necatrix, a destructive soil-borne fungus that causes white root rot in a wide range of agricultural crops, including fruit trees and grapevines.

The virus acts as a biological regulator through a mechanism known as hypovirulence. By infecting the fungal host, the virus reduces the pathogen's ability to infect plant tissues and limits its overall vigor, essentially turning a highly aggressive pathogen into a less harmful strain.

The host range of Rosellinia necatrix includes various woody perennials and crops. The virus propagates within the fungal mycelium and spreads to other fungal colonies through hyphal anastomosis, which is the process of fusion between the hyphae of different fungal individuals.

Symptoms of the viral infection within the fungus are characterized by inhibited radial growth of the colony and a noticeable reduction in the enzymatic activity required for the fungus to degrade the plant cell walls. These physiological changes serve as the primary indicator that the fungus is being impacted by the mycovirus.

Current research efforts are focused on utilizing Betapartitivirus roselliniae as a biocontrol agent. By introducing virus-infected strains into affected soils, growers can potentially suppress the natural fungal population, thereby protecting orchards and vineyards without relying exclusively on chemical fungicides.