The Oenophile's Guide to Grape Sex

Wine grapes have been sex-starved for centuries to satisfy our palates.

So keep that stem to yourself, Mr. Merlot. Only viticulturists get to touch the likes of luscious Ruby Cabernet. Otherwise, a wine’s flavour can be dramatically altered when plant nookie occurs naturally in fields from Bordeaux to the Niagara region.

That abstinence has been great for the discriminating oenophile, but not so great for the grape.

It’s been farmed to remain chaste over 8,000 years while filling amphora, flagons and, more recently, crystal stemware with modern vintages pressed from cloned berries not much different from those fermented by ancient civilizations.

The lack of fruity booty action means grapes have become one large, genetically stagnant family — which makes the crop vulnerable to ever-evolving diseases, pests and fungi, says Canadian geneticist Sean Myles.

“If the grapes don’t change and the pathogens do, then it’s an arms race between pathogen and the host,” says Myles, a researcher at Cornell University who’s developed a gene chip that quickly identifies genetic traits in grapes.

Myles would like to see some pulp friction — the breeding of new grapes to find pest- and disease-resistant plants. His gene chip could speed up this experimentation by years, if not decades, to detect hardy, wine-worthy plants.

The problem: Breeding is expensive and time-consuming. It could take 30 years for a new hybrid grape to become commercially available. Many experiments don’t make it to market at all.

Europe is slower to embrace change, but Canada — a newbie in the wine game — is not.

The l’Acadie grape, for instance, is a hardy 20th century cultivar born and bred in Vineland. It turned out that Ontario’s summers were too hot for the grape, but Nova Scotia’s cooler climes were perfect.

“I find in the new world, we tend to be more willing to try things because we’re not burdened by tradition,” says Ed Madronich, chair of the Wine Council of Ontario and president of Flat Rock Cellars in Jordan, Ont.

“We have hybrids where we’ve crossed breeds . . . with (native) labrusca grapes that are winter-resistant and (cultivated) vinifera varieties to create things like baco noir, a big bold red that people love and we can grow here in Niagara.”

Myles led a team of researchers that studied more than 1,000 samples of the domesticated grape Vitis vinifera and its wild relative, sylvestris, from batches in Geneva, N.Y., and Davis, Calif. The team extracted DNA from grape leaves to develop a genetic fingerprint for each vine using more than 5,000 sites in the fruit genome. Their work was published in the Proceedings of the National Academy of Sciences in January.

What Myles didn’t expect to discover was that 75 per cent of grape cultivars (plants bred for certain characteristics) are directly related as parent, offspring or sibling.

It’s a tight bond that allows vintners to perfect their wines by growing clones, which are genetically identical plants snipped from existing stock. Should natural plant sex unexpectedly occur from winds blowing fertile matter across neighbouring vineyards, it’s not unusual for those offspring to be weeded out.

“Once we have a plant that we like a lot, we don’t want it to have (natural) sex because it will change that plant,” says Gina Haverstock, a Nova Scotia winemaker and Myles’ wife.

“It might change the flavour of the grape, it might change the growth habit, it might change many things.”

Stubborn loyalty to go-to grapes may present problems for growers if chemical insecticides and fungicides are banned — a day many in the industry feel is coming as consumers increasingly demand untainted food and drink.

“A lot of regions are still using varieties that have been vegetatively propagated for hundreds of years,” says Myles, “and that doesn’t really make a lot of sense scientifically but it makes a lot of sense commercially, so it’s a conundrum.

“When it comes to horticulture, grapes are so much more romanticized than any other crop. People don’t realize they are requiring quite a bit of (chemical) spray. Seventy per cent of the fungicide used in the U.S. is used on grapes. (Grapes) need to be treated chemically in order to produce the amounts we demand (for wine).”

Wineries will have to think outside the Tetra Pak should governments outlaw chemical sprays.

Myles says growers have three main options: breed hardier varieties of grapes (his gene chip comes in handy here), go completely organic (a labour-intensive prospect for high-volume commercial businesses, or use genetically modified strains to combat insects and pathogens.


Traditional wine markets have survived one sweeping, deadly scare — barely.

In the 19th century, European vineyards were almost wiped out by the phylloxera louse.

A desperate but successful fix was found in grafting shoots onto American root stalk, which was resistant to the aphid. Yet after that disaster, growers didn’t aggressively continue to diversify.

More recently, that attitude is changing, with research and development picking up in Germany, Italy and France, notes Myles.

In Ontario, the industry tries to keep chemical sprays to a minimum, but sometimes they’re necessary to save crops, Madronich says.

“We know we’d like to reduce sprays. We know that mildew (a rot) is a problem for us and we know there are bugs and insects affecting grape vines, but we tend to find solutions.”

Those solutions can be a blend of chemical, organic and old-fashioned elbow grease, says Madronich.

His Flat Rock Cellars is not an organic operation, but when rot and bugs appear, his 32 hectares of plants are first hand-tended. Leaves are clipped by hand for better air flow to prevent rot taking hold when hot, humid, rainy weather smothers the area. Powdery and downy mildew are two types that might require chemical fungicide, since they can quickly decimate a crop.

Though the grapes aren’t having sex, the mating game is used to deceive a killer pest: the grape berry moth.

Pheromone traps are set away from the plants to lure the male moth to a scent he believes is from a female moth. The trap confuses the unfortunate bug, which lives for about 24 hours, and curtails the need for insecticide.

“We tend not to use insecticide, but if I ever had a really serious insect problem, I would use it because I’m a small business and (an infestation) could ruin my business,” Madronich says.

The largest centres of Canadian winemaking are in British Columbia and southern Ontario. However, Nova Scotia is emerging as a plucky upstart, using l’Acadie blanc wine to bump up its output, says Haverstock, the winemaker at Gaspereau Vineyards near Wolfville, N.S.

Sipping wines with DNA rooted in antiquity is an oenophile’s pleasure — after all, he or she may be drinking much the same thing a Renaissance king enjoyed. But surely there’s room on the wine lover’s palate for newer tastes.

People like Haverstock are banking on it.

Written by Mary Ornsby. Source - TheStar.com