Another important step has been taken along the path to creating a range of new grapevine cultivars with high resistance to fungal pathogens.
Four years of trials in the Riverina have built on initial work in the Barossa with encouraging signs, and Wine Australia has now funded further studies in Mildura and Orange.
The quest began more than 9 years ago when Dr Mark Thomas and colleagues at the CSIRO bred around 8000 new grape varieties – all of them hybrids of European (Vitis vinifera) and American species – to identify those that were resistant to Powdery Mildew and Downy Mildew.
Using DNA technology, these were whittled back to a more workable 1200 varieties for testing in the field, and eventually to what was considered the 20 reds and 20 whites with the greatest potential. These vines represent the first generation of mildew resistant vines produced using marker-assisted selection in Australia.
Vine growth, berry parameters and water use efficiency were closely monitored in the Barossa, then in 2014 a new evaluation and demonstration site was established by CSIRO and the NSW Department of Primary Industries (NSW DPI) at the National Wine and Grape Industry Centre (NWGIC) in Wagga Wagga.
The aim was both to test how well and how differently the 40 performed in a different environment, and to get the sector involved in evaluating both the vines and the resulting wines. A first batch of wine from the white varieties was made last year and the feedback from the first few informal tastings has been positive.
‘This project was all about establishing the new site and seeing how the vines grew in the region’, Dr Thomas said. ‘We need to know if they would show resistance to Powdery and Downy in a new region – and they did.’
There were some differences in performance between the Barossa and the Riverina – in some cases greater than might have been expected – and this will be factored in to the next phase of work in all four trial sites.
Dr Thomas notes in his final report, for example, that ‘the range of yields and pruning weights observed for the white selections indicated that different management requirements for water and nutrient applications would be more appropriate’.
Mildura and Orange were chosen as the new sites to provide an even greater range of environments and because the CSIRO and NSW DPI respectively have facilities there that will support controlled research trials.
Thomas is already thinking ahead, however. The trial sites will also serve as source blocks to provide cuttings for future use by the sector.
‘The next step would be that if a company likes a particular wine then CSIRO could negotiate an agreement with them to allow them to test that variety on their own land, so we need the source material to be able to do that’.
- Dr Mark Thomas
‘I’m trying to achieve a number of objectives with this project; I want to do some good research at the different sites but also have these sites as a source of cuttings – a pathway to adoption.’