Wheat

Andrew Ross’s lab at Oregon State University smells like a bakery. That’s
because it is. The cereal scientist wears checkered chef’s pants and a white
chef’s coat. There’s an oven in the corner and an empty 50-pound sack of flour
near the emergency shower. Golden loaves of sandwich bread are lined up on
a metal rack. Flour dusts almost everything.

Ross sprinkles durum semolina on a proofing board. He pauses. He’s multitasking.
Oh yes, pull the loaves of dough from the rack where they’re rising. He’s making
a rustic ciabatta. Half of the flour in it is ground from wheat called Norwest
553 that OSU helped develop. In 26 minutes he’ll know if his experiment is
a success.

Ross is on a quest to make world-class bread out of Pacific Northwest wheat.
He’s just one piece of a team at OSU that’s collaborating to help the wheat
industry make dough. And it’s a lot of dough. Oregon’s farmers sold $312 million
of wheat last year, making it the state’s fourth-largest agricultural commodity.

Wheat has been a staple of civilization ever since it was domesticated about
10,000 years ago in the Fertile Crescent of the Middle East. No, early Neolithic
villagers weren’t out roaming alluvial terraces, lassoing wild wheat, and housetraining
it. But through centuries of repeated sowing and harvesting, these pioneering
farmers were selecting (albeit sometimes unintentionally) plants with large
grains, erect stems, and spikes that didn’t shatter and spill their kernels
on the ground. It was a primitive, slow process.

If only they had had Jim Peterson. The OSU wheat breeder is doing basically
the same thing, only faster, smarter, and with much bigger words. He introduces
desirable genes into wheat that is lacking them. But introducing a gene into
a spike of wheat isn’t a simple handshake. It’s an eye-squinting job involving
tweezers and scissors, essentially neutering the male anthers on the wheat
flower. To be clear, this is not the same process as genetic engineering, which
involves modifying genetic information in cells by adding single genes or fragments
of deoxyribonucleic acid (DNA).

Peterson, who started working at OSU in 1998, carries on a long tradition
of wheat breeding at the university. He has been involved with the development
of several varieties that thrive in Oregon, including the high-yielding Tubbs
and Tubbs 06; ORSS-1757, which is excellent for cookies and cakes; Goetze,
which is suited for the Willamette Valley; and ORCF-101 and ORCF-102, which
resist a particular herbicide.

To understand how traditional breeding works, it helps to know a little something
about the sex life of wheat. Wheat is, one could say, an incestuous plant.
The male anthers pollinate the female stigma in the same flower, rarely straying
outside the house, let alone the neighborhood. That is until Peterson and his
crew come along. They’re the Match.com for wheat.

Every spring, these matchmakers can be found sitting on stools in a field,
hunched over wheat spikes at OSU’s
Hyslop Farm a few miles outside of Corvallis. They carefully snip off the tops
of selected flowers, which each contain three tiny anthers and a white, speck-sized
ovary. They remove the anthers with tweezers as if plucking an eyebrow. A pro
can perform this surgery on 15 or 20 spikes in an hour, Peterson says. A couple
of days later, they choose another wheat variety with a desirable trait—say
resistance to a certain fungus—and sprinkle its pollen onto the once-sheltered
ovary. They arrange about 600 genetically different marriages like this each
year.

Subsequent wheat generations are eventually planted in field trials around
the state. Right now in Pendleton and Corvallis alone, there are about 40,000
genetically distinct lines. With luck, maybe one or two of them will make it
to the market in five or six years, says Peterson, who also serves as the chair
of the National Wheat
Improvement Committee.

One reason the process takes this long is that researchers have had to cross
their fingers and wait until the harvest to see if the trait they want actually
shows up in the wheat. If the trait involves resistance to a disease, it could
take several years to determine its effectiveness.

OSU cereal geneticist Oscar Riera-Lizarazu, though, is trying to speed up
this process through genetic mapping. Genetic mapping is a bit like using Google
maps to find a gene on a spindly chromosome, except you can’t zoom in quite
as much, so you have only a rough idea of where the gene is. What you can see,
however, are genetic markers, which are sequences of DNA that are found near
the gene you’re looking for. So if the markers are present, you can be almost
certain that the gene is there.

The genetic mapping of wheat, however, is no small task. The wheat genome,
the entire collection of genes, is five times bigger than the human genome,
and it can take years to identify some markers, Riera-Lizarazu says.

Riera-Lizarazu’s lab has identified markers associated with genes responsible
for extra-soft kernels and for resistance to several diseases. So if Peterson
wants to know if wheat he’s growing has these traits, he’ll send some of its
kernels to the lab where the DNA will be extracted and amplified. In only a
couple of days, he’ll have the results. There are lots of traits, and Riera-Lizarazu
has mapped markers for just a handful, so field trials are still necessary
in many cases.

While developing new wheat lines, OSU’s researchers keep in mind what the
market wants. “Behind everything we do, there must be a product at the end
of the day,” Peterson says.

That’s where Andrew Ross fits in. He and his team make noodles, bread, cookies,
sponge cakes, and pancakes from the wheat Peterson breeds. He tests the kernels
and dough for key traits like color and protein levels. One machine in his
lab, for example, weighs kernels one by one, measures the moisture in them
and crushes them to see how hard they are. Another device drops a miniature
guillotine blade onto unsuspecting cookies to measure their tenderness. A third
piece of equipment mixes a smidgen of flour and water, analyzes it, then prints
out what looks like a violent seismogram that shows if the dough will be soupy
during mixing and how long it takes to reach the optimal consistency. “We can
eyeball these graphs and tell you—just like that—if we’re going to keep the
wheat,” he says.

In the United States, wheat falls into six classes: hard red winter; hard
red spring; soft red winter; hard white; soft white; and durum. Most Oregon-grown
wheats are soft whites, which are generally lower in protein and make excellent
cakes and cookies. Hard whites make good Asian-type noodles as well as bread.
Hard and soft reds are also used in bread.

To make bread, you need to have flour with enough high-quality protein to
hold the loaf together. To produce a high-protein content, it helps if the
wheat is stressed late in the season by dry, hot weather. Oregon’s cool summers
often don’t cooperate, instead producing more starch and less protein in the
kernels, perfect for pancakes and pastries. Now OSU’s wheat-breeding program
is working to develop hard wheat varieties better adapted to the Northwest’s
climate. As it does, Ross wants to be there, ready with baguettes, boules,
and bâtards in hand to show that, yes, hard wheat grown in the Northwest can
make mouth-watering breads.

The timer on the oven beeps. Ross opens it and pulls out a loaf of toasted-brown,
crunchy ciabatta. “Beautiful,” he says as he slides it onto a rack. “You can
hear the crust crackling. When you hear the crackling, it’s like music. You
think, Oh, I’ve done well.”

Web resources

Andrew Ross' blog Bringing food chemistry to life