Cross Pollination: A problem?

At dinner last night I was explaining how small many of the Cote D'Or vineyards are, sometimes with different clones in adjoining vineyards, and someone asked if this created a problem with cross pollination. I had to admit I didn't know the answer, nor for that matter whether equally unintended cross polination between varieties or even between the various vinifera species presents problems. I guess I should have stayed awake in highschool biology class. Anybody care to comment?

I doubt it Clint. My understanding is that virtually all production vines are grown from cuttings.

Cross pollination is a serious issue for folks who breed vines or other vegetation for that matter. It's fascinating to see the care that is used to prevent and control pollination in plant nurseries.

Funny - I was thinking about this subject myself ...

Its true that the seeds from the grapes are not used - propagation is done by cloning, but how about say a Chardonnay flower that is pollinated by a neighbouring Cabernet or Concord?

It is that the grape is always a Chardonnay grape and doesn't take characteristics from the father plant, but its seeds do?

Generally vines are propagated from cuttings. I've done this. A cane is cut from a vine with 3 buds when it is dormant. The cane is planted with 2 buds in the ground to become the roots and the top bud above ground to become the vine. Grafted vines are made by splicing the desired grape onto a compatible rootstock. In this case, the vine will have the growing characteristics of the rootstock with the fruit of the desired grape. Different clones are the result of a genetic modification in the genes of a bud. Unless one is trying to develop a new type of grape, seeds are not used to start vines. If the new type is a cross between 2 vines of the same species, such as vinefera (Chardonnay X Chenin Blanc) the result is a new variety. If the new type is a cross between 2 vines of the different species (Chardonnay X Delaware), the result is a hybrid. If the new type is a cross between 2 vines one or both a hybrid, (Chardonnay X Seyval Blanc) the result is also a hybrid (Chardonnel). Many seeds are planted when trying to produce a new hybrid, as the genetic diversity is great in seeds. The seedlings are planted, assigned numbers and studied for many years. Most are not successful. Those that are successful are then given trial plantings before being given an official name. The genes in seeds have no effect on the flavor of wine being produced from the fruit of that grape berry.

"It is that the grape is always a Chardonnay grape and doesn't take characteristics from the father plant, but its seeds do?"

I would think so, Peter. The pollen itself might persist for two months or so on the surface of the berries, vines and leaves, and possibly appear in the juice.

But at the cellular level, the male and female cells would be interacting and dividing to form the seed. The plant would be make the berries surrounding the seeds using genetic codes already part of the plant itself.

I believe you will get more or less fruit depending on how many of the grape flowers are pollinated; I believe grape berries are formed only if the grape flower is pollinated.

Certainly that's the way it works in tomatoes. I did a high school experiment years ago "painting" tomato flowers with pollen to encourage fruiting and in a couple of cases to try to create a hybrid tomato. Only pollinated flowers would set fruit. But all of the fruit on the plant was the same no matter what pollen I painted the flowers with.

" Only pollinated flowers would set fruit. But all of the fruit on the plant was the same no matter what pollen I painted the flowers with.

That's just about it, Bob.

But there are cases of field hybridizing without human intervention--those cases are called things like Catawba, Isabella...whether they cross pollinated or did some sort of seed blending???

Inconsistency (not to mention sporadic pollination) is the reason grapevines are cultivated to be self-pollinating.

But there are cases of field hybridizing without human intervention--those cases are called things like Catawba, Isabella...whether they cross pollinated or did some sort of seed blending???

Yup, and it has also been surmised that Norton, which we normally think of as pure aestivalis, could have arisen as a field hybrid between V. aestivalis proper and Catawba. Apparently it's got something to do with the fact that the vine is self-pollinating with perfect flowers, and this would indicate a bit of vinifera parentage somewhere down the genetic line. Catawba and Concord, for example, are known to have some residual vinifera in their genetic makeup.

Not a problem.

The only part of the grape that is produced under control of the cross-pollinated genes is the pip--the grape seed itself. The flesh and skin that surround the pip are produced under control of the vine that bears the grape. Thus, a grape on a chardonnay vine will always be a chardonnay grape, even if the flower from which the grape developed was fertilized by pollen from another variety.

-Paul W.