Dr Mark Thomas’s first job as a Postdoctoral Fellow with the CSIRO was to develop an objective way to identify grapevines using DNA markers known as microsatellites or SSRs. It quickly became the accepted method globally.
Twenty-five years on, he has developed an even better system and is about to use it to take perhaps the biggest step yet towards equipping Australia to create a national winegrape germplasm collection.
He will lead a two-year project, funded by Wine Australia, to DNA profile – and thus confirm the identity of – around 500 unique varieties and nearly as many clones currently held in collections around Australia.
This will be an international project that will also include collections in France, Italy and Germany.
Germplasm collections house the mother vines that are used to stock source blocks, which then provide cuttings to be propagated by nurseries for on-sale to commercial vineyards.
Being able to authenticate a variety’s identity and source is important in Australia, given our stringent label integrity provisions, but there has been growing concern in the sector about the health status, management and future of numerous grapevine collections and source blocks.
The two biggest germplasm collections – those managed by CSIRO and the South Australian Research and Development Institute (SARDI) – have not been fully accessible to the Australian grape and wine community for several years.
As a precursor to the new project, four key things happened in 2013. First, the then GWRDC commissioned a review to document what germplasm collections existed and examine best-practice germplasm management in other industries. The final report noted not only the number of different varieties, but also that some pre-phylloxera heritage material is probably unique to Australia.
‘We do know that some of the varieties – at least in the CSIRO collection, based on work done many years ago – don’t exist in the French collection or anywhere else, simply because they were early imports into Australia and they’ve been lost and don’t exist in Europe anymore’, Dr Thomas said.
Following the release of the review, Wine Grape Growers Australia formed a Germplasm Management Working Group to develop a business plan for the future management of the various collections.
At about the same time, GWRDC funded two other projects: one to develop an Australian Vine Quality Standards Scheme for Vine Assurance and the other for Dr Thomas to evaluate a new marker type for DNA identification know as SNPs (Single Nucleotide Polymorphisms).
SNPs will be used to assess all varieties as part of the new project. It’s a sophisticated technology and not that difficult or time consuming to use. The complexity comes with the task at hand.
‘For each individual variety in Australia, such as Cabernet Sauvignon, we want to compare our examples with ones from France, Italy and Germany, if we can find them’, Dr Thomas said. ‘And in theory they should match.
‘We expect there to be some mismatches. We know from the scientific literature, based on the DNA markers that have been used so far, that all collections are finding errors.’
The reason is historical. All national collections were created before DNA typing existed; everybody relied on where they got something and what they believed it to be, which was supported where possible by ampelographic assessment. And that’s what was recorded.
Dr Thomas is less concerned with what discrepancies might exist overseas than with creating a definitive list of what Australia owns and uses. The question for the Australian grape and wine community will then be how it wants to use that list, and what sort of germplasm collection(s) it wants to create.