Ghabrivirales

Ghabrivirales is an order of viruses that primarily contains mycoviruses, which are viruses capable of infecting fungi. In the field of agronomy, these viruses are of significant interest as they often inhabit phytopathogenic fungi. By infecting these pathogens, Ghabrivirales can significantly alter the interaction between the fungus and the host plant, often acting as biological regulators.

The causative agent consists of double-stranded RNA viruses. The nature of the "disease" is unique because it is not a direct viral infection of the crop plant, but an infection of the fungus that parasitizes the plant. This phenomenon results in hypovirulence, where the fungus loses its physiological ability to cause severe disease symptoms in the infected host plant.

These viruses affect a variety of fungal pathogens that attack crops such as cereals, fruits, and vegetables. Symptoms on the plant are often manifested as a reduction in disease severity. For example, powdery mildew or rust infections appear less aggressive, with reduced fungal biomass and inhibited sporulation, which directly protects the crop from premature wilting or yield loss.

Development and spread of Ghabrivirales are inherently tied to the life cycle of the fungal host. The virus transmits horizontally through hyphal anastomosis and vertically through spores. Transmission is most successful under high humidity and optimal temperatures, which promote fungal growth and increase the frequency of physical contact between fungal colonies, facilitating viral spread.

The impact is generally positive for agriculture, as these viruses reduce the damage caused by fungal diseases. Protection strategies should focus on maintaining the ecological balance of the field:

• Avoid excessive fungicide use that might kill beneficial fungal populations.
• Implement integrated pest management (IPM) practices.
• Encourage beneficial soil biodiversity.
• Use resistant crop varieties to prevent initial fungal establishment.