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Posted 13 August 2004. PMN Crop News.

Wild Potato's Gene May Protect Vulnerable Spuds

Agricultural Research Service, United States Department of Agriculture.

Washington, D.C. (August 9, 2004) - 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 gene.

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 Beltsville, Md.

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.


Marcia Wood

Agricultural Research Service, USDA

(301) 504-1662