January 17, 2011

A Vine Distinction

Clone *

    Winegrape vines are propagated from cuttings; therefore, each plant is a “clone” of its parent. Varieties can also mutate into a number of clonal variations over time. Most vineyards are planted with a selected variety of clones of the same grape.

There are an estimated 10,000 varieties of winegrape, with roughly 6,000 varieties currently used to make wine. Yet despite this wealth of choice, there are relatively few winegrapes in widespread use.

The winegrape vine is somewhat prone to mutation. One theory is that all grapevines (at least in Europe) are descended from a distant relative of the Muscat grape, which proliferated in the region of the Black Sea. Once humans decided to farm rather than roam, they began to cultivate. It was natural to save the seeds from the best examples to plant for next year. And as with carrots or wheat, this also applied to winegrapes. The grape’s propensity to mutate was both good news and bad news. A new version of the plant might create an even better wine than its parent plant. But if you can’t predict what the plant’s seed will produce, how do you recreate that special variety? The answer is to plant parts of the original plant rather than the seeds. In effect, you simply clone the desired plant.

There you have plant husbandry in a nutshell. Plant the sticks, not the seeds. That way you know that the resulting vine will produce exactly the same grapes as the parent plant ... mostly. There is still the issue of spontaneous mutation. That too has a silver lining. Take that interesting stick (mutations quite often show up as a single cane on a parent vine) and plant it. So when your pinot noir vine produces a cane filled with light blue grapes, plant that cane and call it “pinot gris”.

Sometimes a mutation will be almost the same as the original plant, but with some characteristic that is worth preserving. That cane, too, can be isolated and cloned. Pinot noir has an estimated 1000 clones, all of which produce a wine recognizable as pinot noir. In Ontario, winemakers are crazy about a clone called chardonnay musqué. The wine is chardonnay in every way, but it has a wonderful muscat element not found in typical chardonnays.
Part of the art and science of planting a vineyard is choosing which grapes and which clones of those grapes to plant. Often the vineyard will be planted with a few carefully selected clones of the basic vine, partly for some genetic diversity but more to achieve a certain type of wine.

No comments: