Understanding the true background and identity of the Chardonnay Gingin clone in Australia
The Chardonnay clone Gingin is one of the oldest and most important Chardonnay clones in Australia. It arrived in Western Australia in 1957, simply called ‘Pinot Chardonnay’, most likely from the foundation vineyard at UC Davis in California, USA. Its popularity and spread in the late 1960s and early 1970s coincided with the introduction of the clones Mendoza and OF Chard, which were released in Australia in 1969 (DPIRD 2018). As all three were prone to millerandage, there was some confusion as to the origins of each clone.
The most likely source of Gingin was the UC Davis Armstrong foundation vineyard, where, at the time Gingin was sent to Australia (1956 or 1957), only four Chardonnay clones were cultivated. These were Chardonnay-1, which could be traced back in the vineyard to the early 1930s; Chardonnay-2, an import from France that was planted in 1951 and removed in 1959; and Chardonnays 430 and 439, which were recent imports only planted in 1956. The original source of Chardonnay-1 is unknown.
In 1961, a Chardonnay sample was received by UC Davis from Mendoza, Argentina labelled ‘Pinot Chardonnay’ (Hyland 1967). The sample from Argentina was planted in the Hopkins Road foundation vineyard at UC Davis and given the name FPS 01A. It was distributed under the name Chardonnay 01A and is known in Australia as the Mendoza clone. In the same year, Chardonnay-1 was sampled and heat-treated. The heat-treated sample of Chardonnay-1 was given the name FPS 02A, was distributed under the name Chardonnay 02A, and is known in Australia as OF Chard. Both were planted in 1964 and distributed from 1966. The origins of the sample from Argentina are not mentioned in any of the articles on this subject, or on the importation record. Mendoza and OF Chard were released from quarantine in Australia by CSIRO in 1969 (DPIRD 2018).
With the many gaps in the historic record surrounding Gingin, the true origins of this Chardonnay clone have been greatly debated for years. In Australia there is also lingering confusion about the relationship of Gingin and Mendoza because of their similarities in phenotype. This project aimed to build on the AWRI’s Chardonnay whole-genome sequencing work already conducted across a range of Chardonnay clones, to determine if Gingin was the same as, or different from, the Mendoza clone.
Determining the origins of Gingin using whole-genome sequencing and clonal marker mutations
Two samples of Gingin vines were collected from Moondah Brook Vineyard in the Swan Valley, WA and two were collected from the Harvey Agricultural College at Wokalup, WA. These sites represent some of the earliest derivatives of Gingin, which were first planted at the WA Department of Agriculture’s Swan Research Station. Two samples of OF Chard were provided by Yalumba Nursery, sourced from different planting years. Finally, samples were provided from the Tiers vineyard in the Adelaide Hills, SA which are thought to be OF Chard (Brian Croser, pers. comm.). Genome sequencing was performed on these samples and compared to genome data that was available for a number of Chardonnay clones (Roach et al. 2018).
Based on a collection of 1,333 clonal markers that were identified across the 27 Chardonnay samples investigated, phylogenetic analysis indicated that the Gingin, OF Chard and Mendoza clones formed a distinct clade, sharing most of their markers, while the Tiers 1 sample represented a novel clone (Figure 1). Gingin, OF Chard (Chardonnay 02A) and Mendoza (Chardonnay 01A) therefore share a common ancestor. Furthermore, the phylogeny is consistent with Gingin being a selection of Chardonnay-1, as OF Chard (Chardonnay 02A) represents a heat-treated and repropagated version of this very early clone. The phylogeny also shows Mendoza as sharing the same progenitor as both Gingin and OF Chard. However, there is no indication as to its origins prior to UC Davis receiving this clone in 1961. Distribution records were only kept from 1956 onwards at UC Davis (Sweet 2018). If what is known as the Mendoza clone today was in fact a selection of that sample from Argentina, then at some point prior to 1956, Chardonnay-1 was most likely supplied to Argentina. There it was propagated, selected and eventually sent back to UC Davis in 1961. In this scenario, serial propagations would account for the large accumulation of mutations in Mendoza compared to Gingin and OF Chard.
Department of Primary Industries and Regional Development (DPIRD) 2018. Timeline and distribution of Chardonnay clone ‘Gingin’. Wine Industry Newsletter. Available from: https://agric.wa.gov.au/n/7170
Hyland, H.L. 1967. Plant Inventory No. 169. USDA. Plant Material Introduced January 1 to December 31, 1961 (Nos. 270535 to 277783). Available from: https://naldc.nal.usda.gov/catalog/39196
Roach, M.J., Johnson, D.L., Bohlmann, J., Van Vuuren, H.J.J., Jones, S.J.M., Pretorius, I.S., Schmidt, S.A., Borneman, A.R. 2018. Population sequencing reveals clonal diversity and ancestral inbreeding in the grapevine cultivar Chardonnay. PLOS Genetics, 14: e1007807.
Sweet, N.L. 2018. Winegrapes of UC Davis: Chardonnay. Available from: http://fps.ucdavis.edu/grapebook/winebook.cfm?chap=Chardonnay
Anthony Borneman, Simon Schmidt