Nerine mosaic virus

Nerine mosaic virus (NeMV) is a significant plant pathogen belonging to the Potyvirus genus within the Potyviridae family. It is a widespread virus that primarily affects ornamental bulbous species, causing systemic infections that can lead to severe degradation of plant health and ornamental quality over successive growing seasons.

The primary hosts of this virus are plants within the Amaryllidaceae family, with Nerine bowdenii, Hippeastrum, and Narcissus being the most frequently reported subjects. Because the virus is systemic, it permeates the entire plant structure, including the bulbs, making long-term control challenging as the virus persists within the propagation material.

Typical symptoms of infection include characteristic leaf mottling, which manifests as light green or yellow stripes, streaks, and mosaic patterns. These visual markers are often accompanied by stunted growth, leaf deformation, and reduced flower production. In some cases, the flowers themselves may exhibit color breaking, which significantly lowers the commercial value of the crop.

The spread of the virus within a planting occurs through two main routes: non-persistent transmission by aphid vectors and mechanical transmission. Aphids pick up the virus from infected plants and introduce it into healthy tissues during short probing events. Furthermore, mechanical transmission during cultural practices such as deadheading, cutting flowers, or dividing bulbs with contaminated tools is a frequent cause of rapid outbreaks.

Control of Nerine mosaic virus is strictly preventive, as there is no chemical cure for infected plants. Management strategies include implementing rigorous rogueing programs to remove symptomatic plants, sanitizing cutting tools with appropriate disinfectants after every use, and controlling aphid populations through integrated pest management. Additionally, using virus-indexed, certified bulbs is the most effective way to prevent the introduction of the pathogen into a garden or nursery.