Potyvirus hibbertiae

Potyvirus hibbertiae is a viral pathogen belonging to the genus Potyvirus, which is one of the most significant groups of plant viruses. This infection specifically targets plants within the Dilleniaceae family, notably those in the Hibbertia genus. Like other potyviruses, it is characterized by filamentous, flexible viral particles containing a single-stranded RNA genome.

The host range is primarily restricted to ornamental Hibbertia species. In commercial nurseries and landscape settings, the virus causes systemic infection, which results in the disruption of essential plant metabolic functions. The pathogen's ability to survive in host tissues throughout the year makes it a persistent threat to plant vitality and commercial production.

Clinical manifestations of the disease are typical of potyviral infections. They often present as chlorotic mosaic patterns on foliage, leaf distortion, and stunted shoot development. Severe cases may result in a significant decrease in the overall vigor of the plant, leading to poor flower production and reduced leaf size, which renders the plant unmarketable.

The transmission of this virus is primarily carried out by aphid vectors, which acquire the virus while feeding on infected plant tissues and subsequently transmit it to healthy hosts. In addition to vector-mediated transmission, human-mediated mechanical transmission poses a major risk; contaminated pruning tools or handling during propagation activities can easily spread the virus within a nursery environment.

Management and prevention focus on reducing the spread of the virus through strict phytosanitary practices. Effective strategies include:

• Sourcing certified disease-free propagation material.
• Implementing an integrated pest management (IPM) program to control aphid populations.
• Promptly roguing and destroying symptomatic plants to eliminate the inoculum source.
• Sanitizing cutting tools with appropriate disinfectants after every plant contact.
• Establishing isolation zones for new plant material arriving in the nursery.