Fiona Constable’s name might be familiar to you. Fiona was a lead researcher on recent Grapevine Pinot gris virus (GPGV) projects, including defining sampling and testing protocols for GPGV in Australia. Fiona has also co-authored all of Wine Australia’s suite of virus fact sheets on grapevine viruses and represents Australia on the international virus stage.

We caught up with Fiona, the Research Leader for Microbiology, in the Microbial Sciences, Pests and Diseases group at Agriculture Victoria, for a chat to ask about her journey through the fascinating world of plant virology.

Fiona’s work is focused on understanding grapevine viruses. “If you can understand how something infects a grapevine, or a tree or a person – or whatever – you have a better opportunity of being able to detect it and manage it,” Fiona said.

Fiona “fell” into plant virology in horticultural crops when working as a technician with the Burnley Plant Research Institute, Department of Agriculture and Rural Affairs (now Agriculture Victoria) in 1989. “In 1995, I ended up in a research scientist position and I started working on Australian grapevine yellows disease, and that sparked my interest in diseases of grapevines,” Fiona said.

A career highlight was working with Charles Drew at Scholefield Robinson Horticultural Services in 2004 on the development of ‘vine health parameters’ for the nursery and vine improvement sector, to encourage the production of high health planting material.

“We felt there was a real need to do some work to get a better understanding of what viruses were out there and improving and validating grapevine virology diagnostics for industry” Fiona said.

“Some of that work was around testing of virus infected vines with different methods and seeing which ones produced the best results.

“We also deliberately inoculated vines with viruses and watched them over a three year period to see how laboratory detection went. That was to inform the timing for undertaking laboratory testing and the frequency of testing needed for effective virus detection.

“We could see that in the first 12 months of an infection, the diagnostic testing is really unreliable, as it takes quite a while for the virus to get around the vine. After that, detection is more reliable, but you still have hits and misses.

“We did this work across some different regions – the Yarra Valley, the Riverland and Sunraysia, and we were seeing similar patterns of infection across the regions, which was very interesting.”

Fiona’s grapevine yellows research was also a career highlight. “We really wanted to improve diagnostics for this bacteria and understand the diversity of the phytoplasmas infesting grapevines in Australia,” she said.

“We monitored the progression of the disease over many years, which informed the development of diagnostics for the disease and an understanding of its impact. And these diagnostic tests are still in use today.”

Fiona also worked on confirmatory testing of Grapevine Pinot gris virus (GPGV) in Australia when it was first detected in 2016.

“It was a significant concern to industry because the Europeans were incredibly concerned about the impact of the virus,” Fiona said. “The Italians particularly have seen an impact on yield and quality in some varieties.

“People have been testing for it around the world and it has spread very quickly in Europe in a short period of time. The reason for that is probably because of blister mites. Basically, you take in the infection on propagation material, then mites feed and transmit the virus to other vines and of course the mites can get wind-blown and move on clothing and equipment to other vines.”

It’s still unclear what the impact of GPGV will be on the Australian wine industry.

To address this, Fiona has worked on sampling and testing protocols for GPGV in Australia and is now supervising a PhD student who is running a national survey to collect samples from different regions in each state to look at GPGV spread in Australia. The student will also use high throughput sequencing to look at the diversity of the disease in Australia.

In a future issue of our e-news, Fiona will share her tips for vineyard owners to minimise virus impact, and her views on the viruses we need to be aware of.

Virus expert Fiona Constable.