Gingin and Mendoza, unravelling the mystery of these two related Chardonnay clones
Travel to Australia and New Zealand and you’ll hear extensive discussion about two clones of Chardonnay: Gingin and Mendoza. They are both regarded as high-quality clones, and both are similar in that they are prone to millerandage (pictured above), which is when during fruit set there are some difficulties, resulting in bunches with normal-sized grapes as well as very small ones (where there are no seeds, but the berry still develops). This is also known as hen and chicken, and it’s not terrible for quality because the small berries have a very high skin to pulp ratio, and also develop at a different rate. It is bad for yields, though.
For a long time, Mendoza and Gingin were thought to be synonyms. This turns out not to be the case. So what’s the true story?
Back in 1955, University of California Davis professor Harold Olmo was awarded a Fulbright grant for Viticultural Research. He travelled to Western Australia where he worked at the University of Perth to complete a report on the grape industry of Western Australia, which at that point was focused on the Swan Valley. This resulted in a 1956 publication titled ‘Survey of the Grape Industry of Western Australia’. In this, he mentioned that there are areas of Western Australia that might be more promising for wine grapes than the Swan Valley, highlighting the south west of the state. In 1957, he sent some cuttings of Chardonnay (then called Pinot Chardonnay) from California to Bill Jamieson at the WA Department of Agriculture, which were initially propagated at the Swan Research Station. The first significant plantings of this Chardonnay clone were planted at Valencia Wines, later known as Moondah Brook, in Gingin, and thus this clone became known as Gingin. It’s now the most widely planted Chardonnay clone in Western Australia.
In 1968, two more Chardonnay clones were imported into Australia from University of California Davis. These were Mendoza and Old Foundation Block Chardonnay (OF Chard). Mendoza had come to California from Mendoza in Argentina in 1961. OF Chard was a heat-treated selection of a very old 1930s selection called Chardonnay-1. This is almost certainly pre-prohibition.
The relationship among these different clones was cleared up by a study published in 2020 by M. J. Roach and colleagues in the Australian Journal of Grape and Wine Research. They took samples of Mendoza, Gingin and OF Chard, plus some others (26 samples in all) and did whole-genome sequencing on them, to look at their genetic closeness. This is not a simple thing to do: often, clonal differences are not readily seen by standard genetic techniques used to identify different varieties. Whole genome sequencing is much more involved. And many clonal differences are to do with genetic features called transposable elements. In brief, this is complex work.
What the study showed is that all three clones are different, but share a common progenitor. It’s likely that this is a very old Californian clone that has then mutated and become different enough that these new clones are identifiably different. What we can say is that Mendoza is not the same as Gingin.
Link to the Roach et al paper: https://onlinelibrary.wiley.com/doi/full/10.1111/ajgw.12448
Other interesting links:
Some history on winegrowing in the Margaret River region
A detailed biography of famed viticulturist and geneticist Harold Olmo
