Potatoes infected with late blight are shrunken on
the outside, corky and rotted inside. Click the image for more information
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Gene May Protect Vulnerable Spuds
By Marcia Wood
August 9, 2004
America's favorite veggie--the
potato--sometimes falls victim to its worst enemy, a disease called late
blight. But Agricultural Research
Service scientists have found a promising gene that might help.
Isolated from a wild Mexican potato, Solanum bulbocastanum, the novel
Sbul1 gene may work in concert with other genes to boost the ability of
popular, domesticated S. tuberosum tubers to shrug off attacks by the
fungus-like microbe, Phytophthora infestans, that causes late blight.
A team led by ARS plant physiologist William R. Belknap at the
Western Regional Research Center at
Albany, Calif., identified the Sbul1 gene, following earlier research by
John P. Helgeson, formerly with ARS at Madison, Wis.
Helgeson had fused S. bulbocastanum with S. tuberosum
potatoes. Then, ARS researchers at Aberdeen, Idaho, used samples of these
potatoes to develop new, experimental tubers that they provided to Belknap.
Each time they crossed, or "hybridized," the Wisconsin potatoes
with other tubers, the Idaho team lessened the amount of genetic material from
the wild potato--narrowing the California team's search for the resistance
At Albany, researchers isolated and copied the Sbul1 gene from one of
the Aberdeen potatoes, then moved the gene into domesticated potatoes for tests
in the specialized greenhouses of ARS plant pathologist Kenneth L. Deahl in
The California group also determined the blueprint, or structure, of the
Sbul1 gene and pinned down its location within the wild potato's genome.
Deahl's greenhouse tests of the Sbul1-enhanced tubers are being
succeeded by outdoor trials in the Midwest.
more about the research in the August issue of Agricultural Research
ARS is the U.S. Department of
Agriculture's chief scientific research agency.