Leek yellow stripe virus

Leek yellow stripe virus (LYSV) is a plant pathogenic virus belonging to the genus Potyvirus within the family Potyviridae. It is one of the most economically significant viruses affecting various Allium species worldwide.

The primary hosts of this pathogen include common onion, garlic, leek, and shallot. Typical symptoms include the development of pale yellow to white stripes along the leaf blades, leaf curling, necrosis, and significant stunting, which severely impacts plant vigor and bulb development.

The biological cycle of LYSV involves non-persistent transmission by various aphid species. When an aphid feeds on an infected plant, it acquires the virus in its stylets and transmits it to a healthy plant within seconds. This rapid transmission makes the virus difficult to contain once it enters a field.

Environmentally, the prevalence of the disease is highly correlated with aphid populations, which peak in favorable weather conditions. The virus also spreads systemically through vegetative propagation, meaning infected bulbs or cloves serve as the primary reservoir for the virus in new planting cycles.

Economic damage is substantial, as infected plants exhibit lower yields and poor market quality. In addition to yield loss, LYSV makes the crop more susceptible to secondary pathogenic invasions, often leading to total crop failure or poor storability of bulbs.

Control and management strategies focus on preventing introduction and minimizing spread:

• Prioritize the use of virus-free, certified seeds and bulbs.
• Implement rigorous aphid management programs using systemic insecticides.
• Apply spatial isolation between production fields and seed crop plots.
• Practice sanitation by removing volunteer plants and infected crop debris.
• Use tissue culture-derived material to rejuvenate seed stocks in garlic production.