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AlFulchino

Winemaker of 30+ years
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i dont know the answer to your query ,,,but you started me doing a search and i came across this nice article:






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<h2>DNA Fingerprinting Reveals Surprise in Wine-grape Family Tree</h2>
August 30, 1999






Editors' Note: For digital images of Chardonnay, Pinot noir and Gouais blanc wine grapes, contact Patricia Bailey, [email protected].</span>

While
sleuthing out the parentage of some of France's finest wine-grape
varieties, researchers at the University of California, Davis,
discovered that somewhere in the distant viticultural past, royalty
mingled with a commoner.

It came as little surprise when DNA
fingerprinting techniques revealed that 16 venerable wine-grape
varieties, including Chardonnay, Aligote and Gamay noir, are the direct
offspring of the classic Pinot variety. But even the researchers were
surprised to find that the obscure Gouais (goo-WAY) blanc, a variety
considered so mediocre that it is no longer planted in France, is the
other half of the parental pair.

UC Davis professor Carole
Meredith, an authority on genetic manipulation and analysis of
grapevines, and John Bowers, a genetics doctoral candidate at the time
the research was conducted, report their findings in the September 3
issue of the journal Science.

"Not only is this finding
historically intriguing, but it also has very practical significance
both for preserving old and for developing new grapevine varieties,"
Meredith said.

"We now know that you can conserve the entire
gene pool of these 16 classic varieties just by keeping the Pinot and
Gouais blanc varieties," she explained. "And we're reminded of the
importance of crossing genetically diverse varieties to produce hardy
offspring."

Meredith and her research group have been working
for several years on genetically characterizing grape varieties so that
California grape growers and vintners can be certain of which varieties
they have. Two years ago, in the course of studying major wine-grape
varieties maintained in the UC Davis vineyards, they discovered that
the highly esteemed Cabernet Sauvignon wine grape is the offspring of
the Cabernet franc and Sauvignon blanc varieties.

Expanding on
that work, the researchers enlisted the collaboration of French
colleagues Jean-Michel Boursiquot and Patrice This. After reviewing the
historical French literature on wine grapes and taking into account
previous speculation on variety origins, they chose 300 varieties from
among the more than 2,000 maintained in a collection near Montpellier,
France, by the Institut National de la Recherche Agronomique.

In
France, Bowers took leaf samples from the 300 varieties, extracted DNA
from them, and then returned to UC Davis where he used the DNA
fingerprinting technique to generate a DNA profile for each variety.

For
years, grapevine varieties have been identified by physical features of
their leaves and fruit. But those traits can vary according to
environmental conditions. In recent years, DNA fingerprinting, which
compares characteristic patterns in the genetic material of a plant,
animal or human, has proven to be a highly accurate way to identify
grapevine varieties no matter where they are growing.

Bowers and
Meredith first compared all the varieties at 17 distinct DNA sites
known as "microsatellite" markers and looked for genetic evidence of
close family relationships. Then they chose 60 varieties for more
detailed comparisons.

Their analysis of these 60 varieties at 17
additional DNA marker sites revealed that 16 of them were probably the
offspring of the same pair of parent varieties -- Pinot and Gouais
blanc. A further statistical test, similar to that used to validate
human DNA fingerprinting results, confirmed the very high probability
that these two varieties were indeed the parents.

"We are more
than 99.99 percent sure that Pinot and Gouais blanc are the original
parents for these 16 varieties," Meredith said. "In other words, there
is less than one chance in a trillion that we're wrong."

Some
wine experts had suspected that there might be a genetic link between
Pinot and Chardonnay, Meredith noted. Grown for centuries in
northeastern France, Pinot is the noble red grape of the Burgundy and
Champagne wine regions, and Chardonnay is its white counterpart, she
said.

But Gouais blanc is quite another story. It was considered
so mediocre as a wine grape that several unsuccessful attempts were
made to ban it in the Middle Ages, and it is no longer planted in
France. Because vineyard owners in the United States adopted only
Europe's finest wine-grape varieties, Gouais blanc also is not grown in
this country.

Even Gouais blanc's name, derived from the old
French adjective "gou" -- a term of derision -- reveals its position of
low esteem.

"It is surprising enough that Chardonnay has such a
lowly parent, but that all 16 of these varieties, which include most
all of the wine-grape varieties grown in northeastern France today,
should have come from the same two parents is quite remarkable,"
Meredith said.

In addition to their disparate status, Pinot and
gouais blanc are physically diverse. The highly productive Gouais blanc
vine yields white grapes while the less productive Pinot bears
bluish-purple grapes. (In the world of wine-grapes, high quality wines
are thought to come from vines that produce relatively light crops of
grapes.)

Interestingly, it may be the genetic differences
between the two varieties that produced the strength and quality in
their 16 offspring varieties.

"Gouais blanc and Pinot have been successful parents, perhaps because of their genetic diversity," Meredith said.

Identification of the two parent grapevine varieties provides useful information to grape breeders, she added.

"We
now know that you'd never want to cross Chardonnay and Pinot, because
you would be more likely to get genetically weak progeny, similar to
the inbreeding problems that occur when closely related people marry,"
she explained, "And, it's very instructive to know that Gouais blanc
can produce wine-grape varieties as fine as Chardonnay."

This
study was funded by the American Vineyard Foundation and the California
Department of Agriculture's Fruit Tree, Nut Tree and Grapevine
Improvement Advisory Board
 

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