A Georgia marriage of old and new technologies has smashed a
plant-breeding record of sorts, taking new soybean varieties
from
zero to commercial reality in less than five years.

“That’s light speed for a breeding endeavor,” said Roger Boerma,
the University of Georgia plant breeder whose team accomplished
the feat. “Thirty years ago, it took 12 years to develop a new
variety. From the mid-1970s, it has required eight years.”

The scientists cut three more years off the time farmers must
wait for a new variety, though, with the help of two key
partners.

Two Key Partners

They knocked off two years with DNA instrumentation developed by
scientists and engineers to sequence the human genome and
provided to UGA by the Georgia Research Alliance. Then the
Georgia Seed Development Commission, led by director Earl
Elsner,
provided for winter seed increases that trimmed off another
year.

As a plant breeder, Boerma is rooted in traditional methods
scientists have proven in the past. But he’s not averse to the
new marvels of genetic technology. The opportunity to combine
the
two presented itself in 1996.

That’s the same year Monsanto made Roundup Ready soybean seeds
available to soybean growers. A single gene, which Monsanto had
inserted from a soil-borne bacterium into soybean plants, made
the plants tolerate the herbicide glyphosate.

Glyphosate Tolerance

Glyphosate, the active ingredient in Roundup, controls just
about
every weed in soybean fields. It kills soybeans, too, unless the
variety has the new glyphosate-tolerance gene. With soybeans
possessing the gene, growers can spray glyphosate over the top
without hurting the variety’s yields.

“It gives them a 30-day application window, not the five- or
six-day window they had before,” Boerma said. That’s important,
he said, because of the nature of the crop for Georgia
farmers.

“There’s a lot of stress on farmers,” he said. “They have to
have
large, efficient operations. And soybeans have never been their
most important crop. It’s always been the stepchild.”

Overnight Adoption

Almost overnight, Georgia soybean growers made it clear they
considered the single genetic trait vital to them. “We were
astonished at how fast growers went to the new technology,”
Boerma said.

In the spring of ’96, farmers began abandoning seeds that cost
them around $12 per acre for the new Roundup Ready seeds at
double the cost. In just four years, traditional varieties fell
from 100 percent of the crop to 15 percent.

The new varieties gave growers the weed control they wanted. A
pristine green corduroy of soybean rows filled their fields. But
their harvests weren’t satisfying. And declining soybean
acreages
dropped further in Georgia, from 650,000 acres in 1992 to about
200,000 in ’99.

Cloud in the Silver Lining

The problem, Boerma said, is that the initial high-tech
varieties, bred in the Mississippi Delta, didn’t perform as well
as traditionally bred UGA varieties, except for that one trait.
They weren’t bred for Georgia’s climate. And they didn’t have
the
key pest resistances bred into UGA-released varieties.

“The growers ended up with less yield than they hoped for,” he
said. “Their profit-loss margin is razor thin to start with. If
they spend more for seeds and don’t get better yields, it’s very
frustrating.”

In May of ’96, though, the UGA College of Agricultural and
Environmental Sciences acquired the glyphosate tolerance gene
from Monsanto, Boerma said. The CAES team immediately began a
backcross breeding program to bring the gene into UGA varieties
Boggs, Haskell, Benning and Prichard.

High-Tech, High Speed

In late 1997, a new DNA marker system became available to speed
up the process. With the high-tech equipment of the GRA-funded
Applied Genetic Technology Resource at UGA, the scientists
quickly identified lines that combined glyphosate tolerance with
the UGA varieties’ best traits.

Then, each time they backcrossed the hybrid with the original
UGA
release, they used the DNA markers to pick precisely the best
plants for the next backcross.

“Usually it takes five or six backcrosses to complete the
process,” Boerma said. “At best, you can breed two generations
in
a year.”

With the help of the DNA markers, though, the scientists
produced
glyphosate-tolerant plants almost exactly (99 percent) like the
superior UGA varieties in just three backcrosses and less than
three years.

Early UGA Releases

Two GSDC-funded winter seed increases in Puerto Rico then helped
get enough seeds to set the first two UGA glyphosate-tolerant
variety releases (from Benning and Prichard) in February 2001.
(Boggs and Haskell will be released in 2002.)

That’s three months less than a five-year process.

“That speed came through the marriage of a traditional, proven
breeding program with DNA technology,” Boerma said. “And the
technology is species-blind. You can do the same thing with
other
crops or even apply it to the improvement of animals. It’s no
longer a matter of promise. It’s here now.”