Potato leafroll virus

Potato leafroll virus (PLRV) is a significant plant pathogen belonging to the genus Polerovirus and the family Solemoviridae. It is a phloem-limited virus, meaning it colonizes the vascular tissue of the plant, which directly impacts the transport of nutrients and sugars from leaves to tubers, leading to substantial physiological stress.

The primary hosts of this virus are members of the Solanaceae family, most notably potatoes, tomatoes, and ground cherries. Infected plants exhibit distinct symptoms such as upward rolling of the leaflets, starting from the lower leaves, which eventually become rigid and leathery. This condition often results in stunting of the entire plant and a significant reduction in the development of tubers.

The development and transmission cycle of PLRV is entirely dependent on aphid vectors, primarily the green peach aphid (Myzus persicae). The virus is transmitted in a persistent, circulative manner. Once an aphid ingests the virus from an infected plant, the virus particles move through the gut into the hemolymph and eventually into the salivary glands, allowing the aphid to remain infectious for the remainder of its lifespan.

The spread of the disease is highly correlated with the environmental conditions that favor aphid migration. Warm and dry weather facilitates rapid aphid reproduction, accelerating the spread of the virus across fields. Once the tubers are infected, the virus becomes latent and persists in them, which acts as the primary reservoir for the subsequent season, leading to severe yield decline.

Economic damage is caused by both the reduction in total tuber weight and the degradation of potato quality. Effective management strategies include:

• utilizing certified, virus-free seed tubers;
• implementing systematic insecticide programs to control aphid populations;
• practicing crop rotation and eliminating weed hosts;
• maintaining spatial isolation from older, potentially infected potato crops;
• removing and destroying symptomatic plants as soon as they are identified.