Potato Growers Have New
By Hank Becker
July 26, 2000
North American potato growers now have
new germplasm that thwarts two key pests-- golden and white
Genetic resistance is crucial to controlling these and other microscopic
worms, called plant-parasitic nematodes, that cause an estimated $9 billion in
losses to U.S. agriculture each year
Methyl bromide now protects more than 100 crops from nematodes and a variety
of other pests and pathogens, but is scheduled to be phased out by January 1,
2005. So developing nematode-resistant germplasm is more important than ever.
The golden nematode, Globodera rostochiensis, can wipe out entire
potato crops by feasting on the plants' roots. These worms attack the U.S.
potato crop only in New York state.
The "white" potato-cyst nematode, G. pallida, is a major
pest of potato outside the United States, and regulators are making every
effort to block its entry into this country. Built-in resistance to this pest
was developed as insurance, in case races of this more aggressive nematode are
accidentally introduced. In countries in South America and Europe where G.
pallida occurs, it causes considerable economic damage to potatoes.
The new germplasm is the result of cooperative efforts by
Agricultural Research Service plant
pathologist Bill Brodie, at the Plant,
Soil and Nutrition Laboratory, Ithaca, N.Y., and researchers at
Cornell University-Ithaca and the
International Potato Center, Lima, Peru.
Brodie says the source of this resistance is germplasm obtained in 1984 from
the International Potato Center. Seeds that resist the two nematodes are being
released by the
University Agricultural Experiment Station and ARS. The germplasm will be
deposited in the U.S. Potato Introduction Station Germplasm Collection at
Sturgeon Bay, Wis., for long-term storage in the ARS potato gene bank.
Some of the new germplasm also resists potato virus Y, which can be spread
by aphids and also affects tobacco, tomatoes, peppers and many other plants.
Scientific contact: Bill B. Brodie, ARS Plant, Soil and Nutrition
Laboratory, Ithaca, N.Y., phone (607) 255-2158, fax (607) 255-2739,