Potato leafroll virus

Potato leafroll virus (PLRV) is a major viral pathogen classified within the Polerovirus genus. It causes significant physiological disruption in host plants by infecting the phloem tissues, which leads to the translocation of essential sugars and nutrients being restricted, subsequently impacting overall plant growth and yield stability.

The primary host for this virus is the potato, although it can infect a range of other solanaceous crops and weeds. These alternative hosts play a critical role in the virus's ecology by providing a bridge for survival during periods when the primary host is not available in the fields.

Diagnostic symptoms include the rolling of upper leaves into a tubular shape, which often become leathery and chlorotic. In susceptible varieties, the infection can cause systemic symptoms such as stunting and the development of net necrosis inside the tubers. This tuber necrosis is a serious quality defect that compromises the marketable value and potential for future propagation.

The spread of PLRV is entirely dependent on aphid vectors, most notably the green peach aphid (Myzus persicae). The virus is acquired by the aphid during feeding on infected plant tissues and is transmitted in a persistent, circulative manner. Once an aphid acquires the virus, it remains a vector for the duration of its lifespan, facilitating rapid spread across commercial potato fields.

Management of the disease requires an integrated approach focusing on prevention rather than cure. Key practices include:

• Using virus-free, certified seed potatoes to minimize primary inoculum.
• Implementing strict weed control to eliminate alternative hosts.
• Applying systematic insecticide programs to manage aphid populations.
• Utilizing resistant cultivars where available to reduce the impact of infection.