Determining Genetic Relationships Between Auxerrois and Chardonnay

Over the Christmas holidays, my husband and I were seeing a lot of commercials touting DNA kits as Christmas gifts. We also watched Henry Louis Gates, Jr. show Finding Your Roots on PBS. Knowing your genetic background is pretty cool.
Knowing a grape variety's genetic background, for me, is pretty cool, too. My husband and I have known that the Auxerrois that we planted and the Chardonnay are offspring of Gouais Blanc and Pinot Noir. This knowledge came from a Science article that came out in 1999, when thoughts of having a vineyard and winery were just dreams.
I blogged about it in 2013, in a blogpost I called 1999 DNA Typing Article Gives Clues. I was unhappy with the photo I took to put on the blog and have been looking for the article (where in the world did I put it?) ever since. Found it! Here is my new (better camera) and slightly modified (better photo editing) attempt at the genetic relationship illustration:

The above illustration seems to suggest that all of the varieties represented on the left hand side are equally related. However, in an earlier paper authored by G. N. Ye, et al., using Random Amplification of Polymorphic DNA (RAPD), a form of genetic analysis, showed that Chardonnay and Auxerrois are much more closely related.
The RAPD technique makes use of PCR amplified fragments separated on agarose gels. In this study, the authors used 53 10-mer primers to generate a total of 464 bands from the genomic DNA of 16 genotypes. The pairwise percentage similarity between genotypes was calculated by the number of bands (amplification products were resolved by electrophoresis on 1.5% agarose gels) shared by both cultivars divided by the total number of bands analyzed.

The results obtained above showed that the similarity between Chardonnay and Auxerrois was 86.7%. Close relationships can also be depicted as a dendrogram:

These references show that the similarity that exists between Chardonnay and Auxerrois is because they are the offspring of Pinot Noir and Gouais Blanc. One consequence of this relationship is that when making blends, Chardonnay and Auxerrois tastes like a seamless blend, whereas Chenin Blanc and Auxerrois in our hands was not quite as seamless.
References:
1. Bowers, J., Boursiquot, J.M., This, P., Chu, K., Johansson, H., & Meredith, C, 1999, Historical Genetics: The Parentage of Chardonnay, Gamay, and Other Wine Grapes of Northeastern France, Science: 285, pp 1562 - 1565.
2. G. N. Ye, G. Soylemezoglu, G. Soylemezoglu, N. F. Weeden, N. F. Weeden, W. F. Lamboy, W. F. Lamboy, R. M. Pool, R. M. Pool, B. I. Reisch, Analysis ofthe relationship between grapevine cultivars, sports and clones via DNA fingerprinting , Vitis, 1998, Vol.37, No.1 pp. 33-38.