To develop tools to enable more rapid screening of new scion selections for desirable consumer traits.
CSIRO has an ongoing plant breeding program to develop scions with genetic resistance to the major mildew pathogens to improve the sustainability of Australian wine production.
The breeding and adoption of new disease-resistant scion genotypes will be further enhanced by the presence of traits that influence consumer acceptance of the wines made from these varieties. The use of genetic markers for important consumer traits will streamline the selection process making it rapid and less expensive.
To select for such traits, during the breeding process, markers are required that indicate to what extent the fruit from a scion will be able to produce certain flavour and taste compounds. The availability of such markers would make it possible to remove genotypes that produce compounds with negative sensory characteristics and to select for those with enhanced production of compounds with positive attributes before the expensive processes of field trials and sensory evaluation are undertaken.
Preliminary work has shown that the concentrations of positive wine volatile compounds, such as acetate esters and linalool–and those with negative attributes, such as the C6 alcohols - segregate in our existing breeding populations. Understanding how positive and negative sensory attributes are controlled genetically in grapes will enable the development of markers to select for specific traits or to eliminate those with potentially negative attributes at the seedling stage.
Genetic knowledge will be used to improve our understanding of the biochemistry behind the expression of these traits in grapes and wine. This will ultimately be linked to viticultural interventions, so that wine style can be tailored in the vineyard. Also, wines from current disease-resistant germplasm will be analysed to understand how their volatile profiles relate to those of currently used cultivars.
Novel scion planting material with durable disease resistance and superior consumer traits will streamline the selection process for the next generation of grapevine varieties, which will give Australia a unique advantage in the global market.