Garlic allexivirus

Garlic allexivirus (Allexivirus alphallii) is a viral pathogen belonging to the Allexivirus genus within the Betaflexiviridae family. It is a widespread agent that frequently contributes to the "garlic mosaic disease" complex, which is a major concern for allium growers globally.

The virus primarily affects Allium species, with garlic (Allium sativum) being the most economically impacted host. It often infects plants in combination with other viruses, creating a synergistic effect that significantly impairs the physiological processes of the affected crops.

Symptoms typically manifest as mosaic patterns, chlorotic stripes or streaks on the leaves, and stunted plant growth. In many cases, the virus reduces leaf vigour, which subsequently leads to smaller bulbs and decreased yields, often accompanied by poor storage quality and high susceptibility to secondary rots.

The transmission of Allexivirus alphallii is mainly vegetative through infected bulbs, which explains why the disease is so pervasive in heirloom or non-certified garlic stocks. Additionally, eriophyid mites serve as vectors, spreading the virus from infected plants to healthy ones during the growing season.

Effective management focuses on preventive agronomic practices, as no curative chemical treatment is available for viral infections. To minimize the impact, growers should implement the following strategies:

• Sourcing virus-free planting material derived from meristem culture.
• Strict roguing of plants showing viral symptoms early in the season.
• Comprehensive integrated pest management (IPM) to control eriophyid mite populations.
• Practicing crop rotation and maintaining adequate isolation distances.
• Sanitation protocols for tools and machinery to prevent mechanical transmission.