The National Plant Biosecurity Diagnostic Network’s (NPBDN) virtual Annual Diagnostics Workshop (vADW) 2024-25 was hosted on Wednesday 13 November. The first webinar centred on plant virology with a focus on tobamoviruses, especially the Tomato brown rugose fruit virus (ToBRFV). It attracted expert speakers from Australia, Europe, and the United Kingdom. 

Australian insights on tobamoviruses 

Dr Fiona Constable from Agriculture Victoria Research, who chairs the High Throughput Sequencing Working Group (HTSWG) within the Subcommittee of Plant Health Diagnostics (SPHD), opened the webinar. She provided updates on the HTSWG’s progress towards establishing high throughput sequencing (HTS) standards, a key element of plant health diagnostics for both Australia and New Zealand.  

Dr Constable provided a background on tobamoviruses, some of which are estimated to have existed for 110 million years. In Australia, there is only one native tobamovirus (yellow tailflower mild mottle virus) found in wild Solanaceae, with nine naturalised species such as tomato mosaic virus (ToMV). To prevent tobamovirus incursions, Australia conducts Solanaceae and Cucurbitaceae seed testing, primarily in Victoria and New South Wales.  

Dr Constable also highlighted the role of the International Committee on Taxonomy of Viruses (ICTV) in standardising virus classification. ICTV guidelines ensure virus names are globally consistent, benefiting regulatory, clinical, and agricultural applications.  

ToBRFV’s spread in Europe 

Prof Rene van der Vlugt from Wageningen University and Research provided an update on ToBRFV’s impact across Europe. The virus, first detected in Jordan and Israel around 2014–15, infects tomatoes, capsicums, and eggplants, and can spread to some weed species. Symptoms of ToBRFV include leaf blistering and mottling in tomato fruit. Mixed infections with other viruses, such as pepino mosaic virus (PepMV), complicate its detection and control. Prof van der Vlugt noted that ToBRFV eradication is no longer feasible in some European regions, where efforts now focus on containment through clean planting materials and routine testing.  

UK containment strategies 

Dr Adrian Fox from Fera Science in the United Kingdom outlined containment challenges. ToBRFV spreads through mechanical contact, including plant-to-plant transfer, handling, and even bumblebee activity. Since 2018, the UK has implemented protocols to manage ToBRFV, though the virus’s resilience complicates eradication. ToBRFV can survive on surfaces for extended periods – up to two hours on skin and six months on hard materials – which highlights the need for strict hygiene practices. Surveillance data show five infected sites in southern England, underscoring the virus’s persistence and need for rigorous biosecurity. 

Innovative student research 

Two PhD students from La Trobe University also presented new diagnostic methods: 

• Gopi Koladiya developed a dissolving microneedle patch for rapid nucleic acid extraction in strawberries, aiming to simplify virus detection. 

• Kamalpreet Kaur shared research on grapevine virus diagnostics, including the grapevine Pinot gris virus (GPGV) and grapevine red blotch virus (GRBV). Her work highlighted the need for improved diagnostics to support Australia’s grape industry. 

This was the first of four webinars in the series, which will run until April 2025. 

NPBDN membership benefits 

The vADW series is exclusive to NPBDN members. Benefits of NPBDN membership include: 

• access to training workshops and proficiency testing 

• contributions to National Diagnostic Protocols 

• networking with plant diagnosticians across Australia 

• travel funding for NPBDN-exclusive workshops 

• access to the NPBDN member portal with diagnostic resources. 

Membership is open to professionals in government, research, industry, and museum-based laboratories. Join NPBDN today to be part of Australia’s vital plant health network.  

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