Assessing diversity and clonal variation of Australia’s grapevine germplasm (Chardonnay)
Chardonnay is one of the dominant grapevine cultivars used for winemaking in Australia. There are now many clones of this variety, some of which have only recently become available in Australia. These clones exhibit variation in a number of viticultural and oenological traits including fruit composition, flavour and aroma profile, ripening time, flower morphology (leading to seedless grapes), bunch morphology, yield and grape colour. This project aims to assess the genetic variation among clones of Chardonnay available in Australia, and evaluate how this variation contributes to chemical and sensory variation in grapes and wines derived from the different clones.
A reference sequence is being created from one of the 15 Chardonnay clones sourced for this project. Work on the assembly of this reference sequence continued during the year. Once completed, sequence data for 14 other Chardonnay clones will be mapped onto this reference genome. This will allow the identification of bases, insertions and deletions that differ among different clones. While the reference Chardonnay genome is being completed, the genome of Pinot Noir (one of Chardonnay’s parents) has been used as a reference.
Understanding of the genetic differences among clones will be combined with knowledge about their different behaviour in the vineyard and winery. This will include both chemical and sensory data from a winemaking trial of ten different Chardonnay clones, completed in an earlier phase of this project.