Soybean to Nematode: Resistance is Not Futile

Agricultural Research Service researchers have found a shortcut to identifying nematode-resistant soybean lines, thanks to a special lab-reared strain of the soybean cyst nematode.

These crop-damaging pests cause more losses than all other soybean pathogens combined, destroying nearly 220 million bushes of soybeans last year.

In greenhouse studies at ARS' Nematology Research Project in Jackson, Tenn., scientists bred 30 generations of soybean cyst nematodes on a special diet--the Hartwig soybean cultivar. Currently, Hartwig is the only commercial variety resistant to all of the nematode races now observed in farmers' fields. The result was a strain of nematodes capable of feeding on Hartwig. The strain is being confined to the lab using special procedures to ensure that it doesn't escape.

According to ARS plant pathologist Lawrence D. Young, the researchers can now use this new strain of nematode as a test population to get a head start on developing new nematode-resistant soybean lines. Otherwise, scientists would have to wait for Hartwig- tolerant nematodes to appear naturally in farmers' fields before breeding new resistance into soybean lines. This approach means a remedy will already be available by the time the problem occurs in the field.

The soybean cyst nematode has been a thorn in the farmer's side since the pest was first found in North Carolina in 1954. It has consistently overcome the best resistance available in soybeans. The nematode is present in most soybean-producing states.

Young will present his findings today at a Society of Nematology conference in St. Louis, Mo. He can be reached at the Adam's Mark Hotel in St. Louis at (314) 241-7400.

Scientific contact: Lawrence D. Young, ARS Crop Genetics and Production Research Unit, Nematology Research Project, Jackson, Tenn., phone (901) 425-4741, fax (901) 425-4741, email YOUNGL@ars.usda.gov.