Grapevine origins examined for better drop
WA researchers are using cutting edge DNA sequencing to examine how grapevine genetics affect the taste and quality of Australian wines.
The three-year joint project between the University of WA's school of plant biology and the Department of Agriculture and Food WA (DAFWA) involves scientists using molecular profiling on a pilot wine variety—cabernet sauvignon.
UWA Assistant Professor and lead researcher Michael Considine says data from 12 cabernet sauvignon 'clones' currently in production in Margaret River, Frankland and Yalumba Vine Nursery in South Australia, would be used to asses vine, fruit and wine development in an effort to enhance the regional excellence of Australian wines.
A 'clone' is a single vine selected for its desirable traits, and the project's origins date back to 1968 when the first clonal selection of cabernet sauvignon vines was conducted by DAFWA at Houghton Vineyard in Perth.
Twenty one elite vines were selected and evaluation trials planted in the Great Southern wine region's Frankland sub-region in 1973 to assess their adaptation to new soil and climate conditions.
Dr Considine says the wine industry has been aware of differences between the clones for many years but recent advancements in genome sequencing technology had made it time and cost effective to apply agricultural genomics—or agrigenomics—to the vines.
He says small mutations in the DNA code affect the gene's function and impact the wine.
Mutations potentially influence flavour
"That particular gene might be important to the flavour of the fruit which therefore affects the flavour of the wine," he says.
"Or it might affect vine performance by making it less vigorous and therefore easier to manage in the vineyard, make it ripen a little earlier or later which has advantages to producers, or it could have no affect or even a negative affect.
"The importance of this project is to identify how they differ and use that information to support whether that particular mutation would be relatively stable or influenced by the environment and gives us tools to ensure those traits are continued as we continue to take cuttings of that clone."
As well as mutations in the DNA sequence, or genotype, the researchers are looking for markers of the clone's identity at an epigenetics level.
Epigenetics are modifications in gene function caused by 'decorations' on the DNA code influenced by environmental factors, such as the transition from winter to spring causing a plant to flower.
Dr Considine says the project will give growers more control over vine selection and propagation.