Q: Some thoughts about vine self-fertility

Wine friends,
While writing on an article about grape gentics, I started thinking about how on earth so many different grape varieties (16 IIRC) could have resulted from the crossing Pinot x Gouais blanc. The thing is that all these (such as Chardonnay, Gamay, Auxerrois, Aligoté, Melon, ...) are old varieties that are results from spontaneous pollinations between the two parent varieties, since manual pollination to deliberately create new crossings did not start until the 19th century. Even if in the older days, I think the vineyards were not as purely planted with single varieties as they are today, apparently Pinot was regarded as a noble grape and thus grown on the better vineyards, owned by the church and the nobility, while Gouais was a simple grape that was grow on lesser land by poorer people, so there should not have been to much mixing of them in the vineyards. Then I am thinking that only if the vine is not self-fertile, so a vine of a certain variety cannot pollinate another vine of the same variety, as is that case for e.g. apples, there would be a reasonable chance that crosses of any reasonable number will be made between varieties from different vineyards. Otherwise I think one would expect that the number of grapes produced by pollination between the same varieties within a vineyard would be so much higher than the spontaneous crossing between varieties grown in different fields, that the crossings between different varieties would be totally lost among all the others within a vineyard. That would be fine, but then the problem for me is that it seems to me that the vine is indeed self-fertile. How else would there be so many grapes produced on each vine? I have never heard that a vineyard with a single variety would have to rely on receiving pollen from another vineyard with a different variety and such a case seems improbable to me. So then I am back to the original question. How could so many chance crossings ever have been found and saved for us to be enjoyed as great varieties? Would they not simply be drowned by the vast amount of crossings between identical varieties?
I hope I have managed to make my point in this rather complicated way and would be grateful for any suggestions or information on this subject.

Cheers,
Anders

I think you're underestimating the ability of bees and other insect pollinators to carry the pollen of one vineyard to the pistils of the vines in another planted in a different variety.

This is precisely why vine flowers, and those of other plants, go out of their way to be attractive to insects that might provide cross, as opposed to self, pollination opportunities.

There is a an absolutely TREMENDOUS selective advantage to mixing genes in as heterogeneous a way as possible. This is the whole basis of sexual reproduction. Reproducing sexually is outrageously expensive compared to vegetative reproduction. You end up starting over from a single cell, versus a complete individual. Yet billions of species--and ALL of the most complex ones--reproduce this way. If you believe in natural selection, there is only one answer to this riddle. The advantages of gene recombination have to so much outweigh the metabolic penalty and genetic informational penalty of starting over completely afresh from a single cell that nearly every complex species, humans included, incur the penalty.

Even hermaphrodite plants capable of vegetative reproduction or self-pollination, such as grapevines, offer BIG rewards to insects willing and able to facilitate cross-pollination. There's an evolutionary reason for this.

Human beings, in contrast, want entire vineyards planted to members of a restricted variety that are as identical as possible. So we plant clones and near-clones of a single variety.

The evolutionary disadvantage of this monoculture is patently obvious. Bacterial, fungal, and other pest diseases routinely take out entire vineyards, or even wine regions. This doesn't happen with wild vines. Here in New England, we have just about every vine pest you could imagine. This is ground zero for Phylloxera vastatrix, Botrytis, black rot, nematodes--we've got 'em all. Yet wild grape vines Vitis rupestris and Vitis labrusca are everywhere. They thrive, and produce abundant fruit, to the the great delight of bird, beast, and human alike. Why? Because these vines reproduce sexually as well as vegetatively. They can stand up to anything.

The bad news is that in general, they produce absolutely crappy wine.

But producing wine isn't part of their agenda. Survival is. Making yummy fruit is merely a way to bribe birds and mammals into transporting the seeds (the product of sexual reproduction) elsewhere. It's a damn effective strategy for the vines around here in New England, as far as I'm concerned. I love them as eating grapes, and I spit out the whole seeds (you DON'T want to bite into 'em--they're awfully astringent) as I walk along picking ripe grapes in the fall.

The wild vines know what they're doing.

Human viticulturalists . . . well . . . .

-Paul W.

The flowering structure of the vine doesn’t seem to be designed for insect pollination. The flowers aren’t really that colorful or “big”. One would think “wind” plays a bigger role in pollination. But I agree that insect and bee visitation would increase the chances of pollination. For this reason, some viticulturalists actually place bee hives in “strategic” locations within the vineyard.

Salute

The flowering structure of the vine doesn’t seem to be designed for insect pollination.

Then again, Randall Grahm complained that his viognier vines were so attractive to bees that they knocked many of the flowers off his vines in their frenzy to get at them.

And even if one discounts insects, wind can carry pollen a long way. And there may be autoimmune responses to discourage self-pollination (i.e., the more different from the female plant that a pollen grain attempting fertilization is, the better its chances are of penetrating the pistil and achieving fertilization).

-Paul W.

According to Dr José Vouillamoz, Gouais is known in the ampelography world as the "Casanova of grape varieties".

Another point on vine flowers - they don't look like much, but they do have a very delicate attractive scent for a few days.

Pinot was regarded as a noble grape and thus grown on the better vineyards, owned by the church and the nobility, while Gouais was a simple grape that was grow on lesser land by poorer people, so there should not have been to much mixing of them in the vineyards.

Thought 1) the crossing happened in the wild. The better wild vines were chosen on grounds of vigour/taste to be propagatedas vineyards came to be planted

Thought 2) After major vineyards had been planted, peasants who owned no land and thus no vineyards made their own wine by picking wild grapes. Some of these were the result of natural crossings of vineyard planted vines grown from grape seeds dropped by birds/animals. Some made better wine and these then came to be selected for for propagation.

Thanks for your replies. I might not have been able to put my thinking into words as I should. thinking a bit more, I think I can concentrate it into two questions:

1) Is a varietal self fertile, i.e. can a pollen from one Riesling plant pollinate another.

2) How come that so many plants resulting from Gouais x Pinot have been found to be valuable enough to be saved to the present days?

the answer to the first question seems to be yes, as far as I can read from Paul's replies:

Even hermaphrodite plants capable of vegetative reproduction or self-pollination, such as grapevines

. However, there is also a caveat:

the more different from the female plant that a pollen grain attempting fertilization is, the better its chances are of penetrating the pistil and achieving fertilization

The latter sounds a bit like a tendency for varieties not to pollinate themselves. So Paul, could you be a bit more precise, can a certain variety pollinate itself or does the production of full grown grapes depend on pollination from other varieties?

Peter's thoughts coincide pretty much with my own:

Thought 1) the crossing happened in the wild. The better wild vines were chosen on grounds of vigour/taste to be propagated as vineyards came to be planted

Thought 2) After major vineyards had been planted, peasants who owned no land and thus no vineyards made their own wine by picking wild grapes. Some of these were the result of natural crossings of vineyard planted vines grown from grape seeds dropped by birds/animals. Some made better wine and these then came to be selected for for propagation.

I think a central point in understanding how Gouais x Pinot have given so many successful off-springs might be that the crossings occurred a long time ago. both varieties have been around for a very long time. Pinot might have been grown in eastern France already when the romans came there and Gouias blanc, also known as Heunisch weiss is often regarded as on of the very oldest varieties there is. I found a result by Regner et al. in Klosterneuburg, Austria, that seemed to show that Heunisch, together with the Fränkisch family is something of the oldest ancestors to many of today's important grapes, including Riesling and Silvaner. If both Pinot and Gouais/Heunisch have been around for so long, they might simply have had time to create all these successful crossings we still have today.

Any more comments?
Anders

Even hermaphrodite plants capable of vegetative reproduction or self-pollination, such as grapevines

. However, there is also a caveat:

the more different from the female plant that a pollen grain attempting fertilization is, the better its chances are of penetrating the pistil and achieving fertilization

The latter sounds a bit like a tendency for varieties not to pollinate themselves. So Paul, could you be a bit more precise, can a certain variety pollinate itself or does the production of full grown grapes depend on pollination from other varieties?

That comment I made was pure speculation. I was speculating about possible mechanisms that might be there to encourage cross-pollination vs. self-pollination. But it was just that--speculation.

Varieties certainly can pollinate among themselves. Individual plants can and do self-pollinate. The grapes that go into our wine are fully fertilized and their pips are capable of germinating and growing into a new vine, were they allowed to do so.

-Paul W.

Varieties certainly can pollinate among themselves. Individual plants can and do self-pollinate. The grapes that go into our wine are fully fertilized and their pips are capable of germinating and growing into a new vine, were they allowed to do so.
-Paul W.

But you do have other varieties in close by vineyards, don't you, Paul? Why do you exclude that your grapes are the result of cross-fertilization from other varieties? In particular since you wrote earlier:

I think you're underestimating the ability of bees and other insect pollinators to carry the pollen of one vineyard to the pistils of the vines in another planted in a different variety.

I'm not trying to be picky, just want to be sure.
/Anders

Anders,

I'm not excluding cross-fertilization at all.

But in commercial vine cultivation, grape fertilization is all but irrelevant. The vines that are planted are vegetative clones of well-isolated varieties or sub-varieties. Only in the research nurseries do they ever plant grape seeds to see what develops at the result of sexual reproduction.

From a wine point of view, it doesn't matter which variety of grape (the same or other) fertilizes the grape flower and permits a grape fruit to form. The characteristics of the body of the fruit are solely determined by the genes of the female parent vine. The genes from the fertilizing male vine are irrelevant to the characteristics of the grape fruit.

So it doesn't matter which grape variety's pollen fertilizes a grape flower and causes fruit to be set. The nature of the fruit is determined solely by the genes of the female vine. The nature of the seed within that fruit is a different matter entirely. It will be an amalgam of the genes from both parents. This is why viticulturalists rely on cloning and don't plant the grape seed.

-Paul W.

On propagation of vines, in the olden days this cloning was done by trailing a vine branch across the ground and covering it with soil. The bit under the soil would develop roots and create a new vine.

In nature very likely a “population” of vines consisted of mainly homosexual (male and female plants) and some heterosexual vines. The male vines didn’t produce fruit, the female vines (which relied on cross-pollination from either a male or heterosexual vine) were very fruitful, and the heterosexual vines (which are capable of self-pollination and do not have to rely on pollen from a male) were also fruitful.
When man comes into the picture, and because he is concerned only with the “quality” of the fruit produced- What does he do? He chooses the fruitful vines and disregards the fruitless vines. As the plant becomes more “domestic” or “cultivated” most of the females die off and more of the “domestic population” becomes heterosexual vines. This is why today most domestic or cultivated vines are capable of self-pollination. Is this the only way they could sexual reproduce? Of course not, there is always that chance of cross-pollination. (Today, if ones goal is to produce a “new” variety we do this intentionally- artificial-pollination). Cross-pollination is very simply the transfer of pollen from the flower of one plant to the flower of another plant. Because the plant has a fairly short window of time to pollinate, weather and climatic conditions will play a major role if the plant self or cross-pollinates. If the “quality” of the fruit at harvest time remains high, and the cluster of grapes are “healthy” who cares if the vines self or cross pollinate.
Now if you are asking if one would be concerned if in nearby proximity of a vineyard there was a population of wild vines of a different species? If the “quality” of the fruit was affected surely this would be a problem. But I don’t believe this would be the case, the only difference would be the seeds and the number of seeds in a grape berry.

Salute

in commercial vine cultivation, grape fertilization is all but irrelevant. The vines that are planted are vegetative clones of well-isolated varieties or sub-varieties. Only in the research nurseries do they ever plant grape seeds to see what develops at the result of sexual reproduction.

From a wine point of view, it doesn't matter which variety of grape (the same or other) fertilizes the grape flower and permits a grape fruit to form. The characteristics of the body of the fruit are solely determined by the genes of the female parent vine. The genes from the fertilizing male vine are irrelevant to the characteristics of the grape fruit.

So it doesn't matter which grape variety's pollen fertilizes a grape flower and causes fruit to be set. The nature of the fruit is determined solely by the genes of the female vine. The nature of the seed within that fruit is a different matter entirely. It will be an amalgam of the genes from both parents. This is why viticulturalists rely on cloning and don't plant the grape seed.

-Paul W.

Paul,
You are missing my point. I know that the character of the fruit is not depending on the pollinating variety, but if the vine is not self fertile, then a given variety would have to depend on pollen from another variety to set fruit at all (as is the case with apples). In such a case, grape fertilization is certainly relevant.

It seems to me, from the collection of what has been written here that the grapevine is indeed self fertile, but I can't say anyone of you has written it explicitly (well almost Victor in your last post, I have to admit).
Cheers, Anders

The nature of the seed within that fruit is a different matter entirely. It will be an amalgam of the genes from both parents. This is why viticulturalists rely on cloning and don't plant the grape seed.

It seems to me, from the collection of what has been written here that the grapevine is indeed self fertile, but I can't say anyone of you has written it explicitly

I think Paul stated it clearly. A vine (lets say Cabernet Sauvignon) pollinated by another vine of the same variety will produce grapes, but if the seeds of that grape are planted it will not produce a Cabernet Sauvignon vine. Vines don't breed true.

Well if vines were not self-fertile they wouldn’t be able to plant them in continuous or solid blocks. Isn’t this what they do in apple orchards, break up the blocks with rows of a variety that is compatible (can cross-pollinate). Besides I believe that grafting two compatible varieties together allows home fruit growers to plant only a single fruit tree and still get a decent “quality” harvest.

Salute

Anders, I have only quickly scanned this thread, so I apologise if I have missed anything (I should be working). But it did occur to me that all the successful crosses you refer to could be the work of man trying to find a better variety. Of course, the unsuccessful crosses would have been discarded, so we never will lget to know the success rate.

it did occur to me that all the successful crosses you refer to could be the work of man trying to find a better variety.

Steve, deliberate crossings between varieties is not believed to have taken place before the 19th century, according to what I have read in literature. However, I believe you are right in another sense (maybe you included it in what you meant). They are certainly the result of the work of man in the respect that they are chosen for some desired quality and then they are further propagate vegetatively, to preserve the properties of the variety.

Cheers, Anders

it did occur to me that all the successful crosses you refer to could be the work of man trying to find a better variety.

Steve, deliberate crossings between varieties is not believed to have taken place before the 19th century, according to what I have read in literature. However, I believe you are right in another sense (maybe you included it in what you meant). They are certainly the result of the work of man in the respect that they are chosen for some desired quality and then they are further propagate vegetatively, to preserve the properties of the variety.

Cheers, Anders

See, I didn't even read you original post thouroughly! Interesting topic though, and I'm going to interupt my work again.

Could it be perhaps be that self pollinated "crosses" are nearly always inferior to the original variety, which typically would be the result of many centuries of selection. A bit like in-breeding in human populations perhaps? So these get ignored or weeded out. Whereas crosses between varieties stand a better chance of having a fortuitous combination of properties? Thus it is the inter-variety crosses that are kept and further propagated, which is why you hear of them now.

Could it be perhaps be that self pollinated "crosses" are nearly always inferior to the original variety, which typically would be the result of many centuries of selection. A bit like in-breeding in human populations perhaps? So these get ignored or weeded out. Whereas crosses between varieties stand a better chance of having a fortuitous combination of properties? Thus it is the inter-variety crosses that are kept and further propagated, which is why you hear of them now.

I think this is certainly true. One speculates that the reason why Gouais has been so successful could be because it came to Eastern France from quite far away, from eastern Europe, and brought fresh blood - or rather genes - into the population.
Cheers, Anders

Anders,
I can think of one v. vinifera variety that is supposed to not self-fertilize: Fiano di Avellino, which supposedly takes its name from "Appiano" because of its need for bees to pollinate it. Or so I heard once upon a time from a Mastroberardino rep.

Mark Lipton

In nature very likely a “population” of vines consisted of mainly homosexual (male and female plants) and some heterosexual vines. The male vines didn’t produce fruit, the female vines (which relied on cross-pollination from either a male or heterosexual vine) were very fruitful, and the heterosexual vines (which are capable of self-pollination and do not have to rely on pollen from a male) were also fruitful.

That is certainly how the wild vines here in New England behave. The majority of the plants have exclusively male or exclusively female flowers, with a tiny percentage being hermaphroditic. The vines don't flower or set fruit every year, and most propagation is asexual, via vine tips that take root.

Humans cultivating these vines have chosen hermaphroditic plants because they are self-fertilizing, and have selected for reliable annual flowering and fruit set.

-Paul W.

Anders,
I can think of one v. vinifera variety that is supposed to not self-fertilize: Fiano di Avellino, which supposedly takes its name from "Appiano" because of its need for bees to pollinate it. Or so I heard once upon a time from a Mastroberardino rep.

Interesting, Mark. I wonder if the reason for this could be that Fiano di Avellino only carries male flowers.
/A

Could male flowers bear fruit?

Salute

Could male flowers bear fruit?

Salute

Eh, sorry, female, of course...
/A