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  • From: "TradingPostPaul" <tradingpost@riseup.net>
  • To: livingontheland@lists.ibiblio.org
  • Subject: [Livingontheland] Selective Breeding Gets Modern
  • Date: Sat, 26 Aug 2006 20:27:14 -0600

http://www.wired.com/news/technology/0,71433-0.html?tw=wn_index_2

Selective Breeding Gets Modern
By Griffin Wright| Also by this reporter
02:00 AM Aug, 25, 2006

Genetically modified food has gotten a chilly reception from consumers,
especially in Europe and Asia. Just last week, Japan suspended imports of
American long-grain rice after authorities discovered that a genetically
modified variety had accidentally mixed with conventional rice.

To skirt such problems altogether, biotech companies are creating superior
plants using genetics technology that is advanced but which falls short of
grafting genes from one organism into another.

"GE (genetically engineered) crops are legal (in Europe), but they don't
sell them anywhere," said Doug Gurian-Sherman, senior scientist with the
Center for Food Safety. "Companies say people won't buy them."

Some of the largest agricultural biotech companies in the world, including
Monsanto and DuPont, are turning to marker-assisted selection, or MAS, as a
way to circumvent the controversy surrounding genetically modified foods.

Scientists say it's an efficient and relatively noncontroversial way to
create designer fruit and vegetable crops with superior disease and pest
resistance, as well as enhanced flavor, texture, skin color or shelf life.

MAS involves analyzing plants for genetic markers associated with desirable
traits, then using conventional breeding methods to introduce the genes
into a host. The markers are used to quickly identify which seedlings are
the superior progeny.

For example, a wild apple variety might have a brilliant red skin. In order
to bring that trait to a domesticated apple, researchers first scan the
apple's genome for the gene that determines skin color. Then, looking at
the wild apple, they search the chromosome containing the skin color gene
for a unique and easy-to-identify segment, which becomes the marker. After
crossbreeding the two apple trees, scientists look for the genetic marker
rather than waiting a few years to see which of the seedlings picked up the
red skin trait.

The technique allows researchers to sort new hybrids in the lab long before
any fruit is grown. This involves taking a DNA sample from each sapling and
using methods such as gel electrophoresis to look for the red skin marker
in the genetic code. Companies are compiling databases of MAS genetic
markers, and while some are making the data freely available, others are
treating marker information as a trade secret.

Most fruit and vegetable species have far more wild varieties than we see
in the grocery store, and many contain valuable traits, such as pest
resistance or luscious fruit, that could be bred into common varieties.

Scientists at Seminis, a seed company acquired by Monsanto in 2005, found
that a wild tomato variety had a natural resistance to tomato yellow leaf
curl virus, which causes a disease that can devastate domesticated
tomatoes. They identified the gene responsible for the resistance and bred
it into a domestic variety.

"Markers have allowed us to rediscover traits tucked away for thousands of
years in wild species," said Seminis spokesman Gary Koppenjan.

New Zealand-based HortResearch uses crossbreeding plus genetic markers to
develop disease-resistant apples, and it is working toward developing
varieties with improved flavor and texture.

"It's an overall assessment of the environment around (genetically
engineered) crops," said Gavin Ross, Hort's vice president of business
development.

Hort hasn't given up on transgenics, Ross said. Neither has Monsanto or
DuPont, but some scientists say MAS is as effective as genetic engineering,
without the protests from farmers and anti-GMO groups.

"We don't need (genetic engineering)," said Thomas Gradziel, a professor of
genetics at the University of California at Davis who breeds peach traits
into almond trees (which are species within the same subgenus) using
marker-assisted selection rather than genetic engineering.

"We can find the traits we need in the peach, and classic breeding is
proven," he said.

Not everyone, however, believes MAS is the solution to the GMO conundrum.

"All these practices are very reductionist," said Miguel Altieri, an
agroecology professor at the University of California at Berkeley. "They
don't go to the root cause."

Regardless of their methods, he said, these companies and scientists are
searching for crops that can thrive in the modern agricultural system. But
the solution, he believes, lies in getting away from monoculture -- growing
just one crop on a plot of land.

When the aim is to develop higher crop yields or pest resistance, Altieri
puts MAS and genetic engineering in the same category.

Altieri has worked with small-scale farmers in many developing countries,
and he believes farmers of the Western world can learn from them. Many of
these small farmers practice cultivation the same way their ancestors did
thousands of years ago: by planting multiple crops in one field.

Diversity allows the natural predators of common pests to proliferate. The
farmers also rotate their crops throughout the year, which breaks pests'
life cycles.

"No matter if you use genetic engineering or MAS," he said, "there is a
trade-off."






  • [Livingontheland] Selective Breeding Gets Modern, TradingPostPaul, 08/26/2006

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