Cab Dore’ Combines Best of Old and New Worlds

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6 Responses

  1. Mark Hart says:

    Lucian,
    I enjoyed the article. I was curious of the basis for your claim that the wild species in Norton, and hence Cabernet Dore, is Vitis cinerea. You mention the earlier claims that Norton was 100% Vitis aestivalis, those claims are erroneous for the reasons you cite. But every paper I have seen does put the wild background in Norton down to V. aestivalis at between 25-75% (probably 50%), and not Vitis cinerea. This includes the Dangl et al. paper you reference – http://naldc.nal.usda.gov/download/41645/PDF

    • Mark,

      Thanks. Excellent question. When I spoke to Dangl after he wrote the paper he said that the DNA evidence could not rule out either wild species as a parent.

      The most convincing evidence for deciding the American parentage of Norton, whether Aestivalis or Cinerea, is found in Pierre Galet’s “Precis d’ampelographie pratique” (translated by Lucie Morton, published in English in 1979). Galet, who I think everyone will concede was the greatest ampelographer of the 20th Century, states on page 142, that … “V. Aestivlis is of no interest as a rootstock because its resistance to phylloxera is only fair (9/20).” “No interest as a rootstock”, Wow!! Norton, on the other hand is one of the most phylloxera resistant of all commercial vines. Since one of Norton’s parents is a Vinifera, with zero resistance to phylloxera, then its American parent would have had to have been a doozy when it came to phylloxera resistance. Aestivalis apparently has barely enough resistance to protect itself, much less impart a large dose of resistance to its offspring. V. Cinerea, on the other hand is described by Galet (page 146) as having “… good resistance to phyloxera…” This, I think, is the most telling piece of evidence.

      In addition, Galet also states that Aestivalis has an “unpleasant flavor’ whereas Cinerea has an “acid flavor”. One of Norton’s great virtues is that it lacks the unpleasant wild flavors that plague the other native varieties (although its acid flavor is famous). If Aestivalis were Norton’s American parent, it is almost certain that the some of Aestivalis’s unpleasant flavors would have been imparted to Norton. Every grape that was ever crossed with a Labrusca, for instance, retains some of that unique and unmistakable flavor. Norton’s flavor is rather neutral, with no wild flavors, which is one of the many reasons why we chose it as the American parent for all the DVR varieties. Aestivalis and Cinerea look a lot alike in many ways, and it wasn’t until Engelman reclassified them as separate species in 1883 that their distinct differences were noted. By then, the Aestivalis heritage story for Norton was ubiquitous and highly resistant to change until DNA evidence and Galet came along to indicate otherwise.

  2. Jon Brudvig says:

    Lucian,

    Thanks for the article and comment. I am really excited to try some of your grapes, including Cabernet Dore’.

    I think I should point out that there are V. aestivalis accessions with very good phylloxera resistance, so I don’t think that argument supports a V. cinerea background for Norton any more than the SSR data does. See Grzegorczyk & Walker, 1998:

    http://ajevonline.org/content/49/1/17.abstract

    All the data I’ve seen, whether DNA or ampelographic, strongly suggests V. aestivalis was Norton’s wild parent.

  3. Jon,

    Thanks. You raise a very important point. All individual wild grape vines came up from a seed and are the product of sexual reproduction so each vine is unique. They also interbreed like alley cats. When we classify them into “species” it’s like classifying people into “races”. It’s often not that clear where an individual belongs. The vine that Pierre Galet is calling Aestivalis has insufficient phyloxera resistance to make it the logical choice for a parent of Norton. Also the unpleasant flavors of Aestivalis are nowhere to be found in Norton or its offspring.

    Either Galet has a vine that is not a typical Aestivalis, or the vines that Grzegorczyk et. al. are calling Aestivalis would be classified by Galet as something else. Who knows? One thing, I think, is certain. The individual vine that was Norton’s parent (circa 1820?) is extinct. We can be thankful that before it was grubbed up by some Virginia farmer it passed on its phyloxera resistance and neutral flavor to Norton, which is truly one of a kind.

    • Jon Brudvig says:

      Lucian,

      Thanks for your reply. I agree; the lines between Vitis species are sometimes blurred, and there has to be natural hybridization taking place.

      I would bet that what Galet and Walker’s lab had were both aestivalis. For a lot of traits, like phylloxera resistance, there is considerable variation within a given species. I’m sure there are aestivalis specimens spanning a wide spectrum of resistance. The same is true for traits like fruit chemistry, flavor/aroma, and fungal disease resistance.

      -Jon

  4. David Hicks says:

    What yeast reccommendations for this grape?

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