Margaret River chardonnay is unique. If you taste Margaret River chardonnay against the best in the world there are flavours that are very specific to the region. The best Margaret River Chardonnay, and especially those of Pierro are known to have both flavour intensity and freshness. This is due the climate and soil, but also the clone of Chardonnay grown in the vineyard. The most commonly planted clone of Chardonnay in Margaret River is the 'Gin-Gin' clone. The clone represents 95% of what is planted in the Pierro Margaret River Vineyards. Until now, it was thought that 'gin-gin' was just another term for the mendoza clone, which is found on the east coast of Australia. Using genetic sequencing data, new research by M.J. Roach, A.R. Borneman and S.A. Schmidt has shown that the 'gin-gin' clone is actually unique to Margaret River and had its own journey into Australia, at a different time to mendoza.
Figure 1. History and timeline of chardonnay clones into Australia. Provided by M.J. Roach. As show, Chardonnay-1 left for mendoza in the 1930's, before being imported back to California in 1961 and named 'Mendoza OF Chard' . This clone was shipped to the east coast of Australia in 1969. On a seperate voyage the Pinot-Chardonnay was brought into gin-gin, Western Australia in 1957. From this point forward the clone was commonly known as 'gin-gin' in Western Australia. The Pinot-Chardonnay or Gin-Gin clone from W.A. was taken from different source material than the Mendoza material on the East coast.
The establishment of Chardonnay in Western Australia began in 1955 through a visit to the state by the prominent Californian viticulturalist Professor Harold Olmo (University of California, Davis). In 1957, 2 years after his original visit, Olmo sent 24 canes of ‘Pinot Chardonnay’ from UC Davis to the Department of Agriculture in Western Australia. This source material was planted at the Swan Research station near the town of Gingin, from which this clone would later derive its name. Today, the Gingin clone is one of the most prominent clones of Chardonnay in Western Australia (Cartright 1993, Fennessy 2018) and forms the basis of some of Australia's best Chardonnay wine. (Roach et al, 2020)
Given the mystery that surrounded the historical provenance and inter-relationships of the clones Gingin, Mendoza and OF Chard, the study done by Roach et al, applied whole-genome sequencing and the established clonal marker discovery methodology and genetic framework (Roach et al. 2018) to attempt to determine the genetic relationship between these grapevine clones. (Roach et al, 2020) . What they discovered was the gin-gin although, similar to OF-Chard and Mendoza is still quite unique.
Figure 2: Whole genome sequencing of common Australian chardonnay clones. The Phylogeny of Chardonnay clones. Unrooted maximum likelihood phylogeny of all Chardonnay samples scaled by substitutions per site. (Roach et al, 2020) .
The new genomics research has revealed that all three clones have a shared heritage, in an old Californian source block at UC Davis. They are, however, quite distinct from each other. In particular, Gingin and Mendoza are as different from each other as they are from any of the other clonal selections of Chardonnay, despite their shared origins. (WBM, 2020)
Figure 3 : Whole genome sequencing of Gin-Gin, Mendoza and OF-Chard clones. The Phylogeny of Chardonnay clones. Unrooted maximum likelihood phylogeny of all Chardonnay samples scaled by substitutions per site. (Roach et al, 2020) . Showing that Gin-Gin is different genetically to Mendoza and more similar to OF-Chard.
Genetic analysis of the Australian clone Gingin, the American clone OF Chard and the Argentinian clone Mendoza suggests that all three grapevine clones share a recent common progenitor. Furthermore, the genetic relationships are consistent with Gingin being an early selection of the UC Davis clone Chardonnay-1. The phylogeny shows that Mendoza shares the same progenitor as both Gingin and OF Chard but has diverged significantly since. As figure 1 shows, its thought that all 3 clones are originally from the source block in California, with Mendoza travelling to Argentina for more than 50 years before being imported back into california and then into the east coast of Australia. With the gin-gin clone sources directly from the OF chard in california. The 60-year old mystery surrounding the origins of Gingin has been solved, with its origins now tracing back almost 90 years to a foundation vineyard in California at the end of prohibition (Roach et al. 2020)
Link to original paper by (Roach et al, 2020)
Comments