How do grapes change

Ciao

I hope you have a minute of time to help me with an as yet un answered question regarding grapes. I under stand that Cabernet Sauvginon is a union of both Cabernet Franc and Sauvginon Blanc. How does this happen? The only thing I can figure is cross pollination. But I thought grapes were self pollinating.

Riesling is a combination of several grapes is Gouais Blanc, known to the Germans as Weißer Heunisch, which was brought to Burgundy from Croatia by the Romans. The other parent is a cross between a wild vine and Traminer. How does all of this happen.

garardo

Gary
A very good question that I can't answer, but I know others will be able to (and the answer will be interesting). I'll throw my own follow-on question in... When people refer to Grape X being the father and Grape Y being the mother, how do we know this (through genetics I guess) and could you also have a grape where Grape Y was the father and Grape X was the mother. Would the offspring be different?

and WELCOME!

regards
Ian

Gary, Hi and Welcome Aboard.....

It is largely due to the DNA research of Prof. Carole Meredith of the University of California at Davis that we discovered how many of these crossings came about, mostly accidentally and mostly in the late 17th and early 18th centuries. Later, such crossings were made intentionally and a good introduction to precisely how the self-pollination of grapes can be avoided and crossing take place can be found on pp 35 and 36 of Robert Weaver's book Grape Growing. Those pages can be seen at
http://books.google.com/books?id=AW8kk3 ... t&resnum=4

Best
Rogov

Vines can be either self- or cross-pollinating. Cabernet sauvignon is a variety isolated from the offspring of sauvignon blanc and cabernet franc parents.

-Paul W.

What they said...

Wild vines are cross-pollinating by nature. Domestic vines are trained to be self-pollinating (the pollen drops down onto the vine below). Self pollinating vines means the vines stay more consistent, and far less prone to mutation and crossing than wild vines do. You can also 'cane propagate' one vine by sticking a cane shoot into the ground and creating another plant from that.

Some growers prefer the slower, more exacting process of vin massale to make new vines, rather than relying on new rootstock and grafting to do so.

Hi Gary

You asked how it happened.

There are two ways of getting a new grape vine.

The first is by cloning it. That is how all the commercial vineyards you've ever seen are created. Cloning happens by taking a cutting from an existing vine. If you want a field of Cabernet Sauvignon then you take cuttings from another Cabernet Sauvignon vine.

The second way is by planting a grape seed and growing that. But grapes do not breed true. If you plant a seed taken from a Cabernet Sauvignon grape you do not get another Cabernet Sauvignon vine. Planting grape seeds is the method used to produce completely new grape varieties.

In olden times pollen from one grape variety sometimes pollinated a flower from nearby other variety and the growing of that seed creted a new variety. Only a very very few of these new crosses were any good; those that were good were then propagated by farmers taking cuttings, or more simply bending down long canes into the ground nearby so they self-rooted.

The large number of varieties that have Gouais and Pinot Noir in their parentage appear to have come about by the close proximity that those two varieties were grown in olden time France with peasants owning the Gouais and the nobility the Pinot.

In olden times pollen from one grape variety sometimes pollinated a flower from nearby other variety and the growing of that seed creted a new variety. Only a very very few of these new crosses were any good; those that were good were then propagated by farmers taking cuttings, or more simply bending down long canes into the ground nearby so they self-rooted.

Peter
Which pretty much answers my sub-question as well - if I've got this right, the original plant is the mother and the cross-pollenator is the father? ... and as for whether if the roles were swapped it would make a difference, well I'm guessing it would, but so would other cross-breedings from the same mother/father combination?
regards
Ian

The mother variety is the one whose female flower was pollinated - in other words - it is the one which will grow the grape which contains the seeds which, when planted, grow into a new variety.

A vinifera has an odd number of chromosones -- 19 -- which is the reason it doesn't breed true.

Other flowers on the same vine pollinated with the same pollen samples will each produce a unique variety, nearly always degenerative.

Creating a good new variety is rare and takes a considerable time, but new varieties are being produced all the time.

(I had a long discussion about grape breeding with Professor Eben Archer, viticulturist for Distell, as part of my research for my book PINOTAGE. His explanation is distilled in Chapter 6.)

Peter
Thanks for that
regards
Ian

Some might find the following article interesting;
http://www.judithadam.com/articles/arti ... _vines.pdf

Salute

Some might find the following article interesting;
http://www.judithadam.com/articles/arti ... _vines.pdf

Interesting perhaps, but this quote is plain wrong isn't it? "The dual-sex hermaphrodite vines no longer required the male stud plants with their unruly genes, and could reliably fertilize themselves with their own pollen. This allowed the development of a stable vineyard community."

I agree, Steve.

I found quite a lot in that article that just didn't make sense to me.

Steve,

That statement about hermaphrodite vines being genetically stable is just plain wrong. There are loads of phenomena (e.g., crossing-over) that can result in genetic variation even when a plant self-pollinates. Granted, there is probably less variation than with cross-pollination.

The main advantage for a vineyard owner of hermaphrodite vines is that you don't have to waste time and space in the vineyard growing male vines that will never produce grapes.

-Paul W.

We can only speculate what went through the minds of the ancient vine growers and that’s all the article is doing. But in the end all they did was select the “choice” vines, which produce a “healthy” crop and produced the “best” wine. Eventually if they became “significant” to man, he gave them a “name” to identify those from other vines.
As Peter May stated mutations are occur in living things all the time, now if that mutation is critical for the existence of that living thing it would eventually become dominate. If not it would eventually just disappear.

Salute