New Soybean Germplasm Line Resists Insects

A new soybean germplasm line will give breeders more options for developing insect-resistant, high-protein soybean varieties for farmers.

Known as Plant Introduction (PI) 417061, the line naturally resists several leaf-eating insects, including velvetbean caterpillar and soybean looper. A research geneticist with USDA's Agricultural Research Service identified the line among the agency's soybean germplasm collection located at the University of Illinois, Urbana.

Insects cause more than $40 million in losses annually to U.S. soybean producers. The velvetbean caterpillar and soybean looper are the country's most serious soybean defoliators, with the heaviest infestations in the southeast.

PI 417061 is not the first soybean germplasm line with insect resistance, but it will add to the diversity of the soybean gene pool, an advantage to soybean breeders. Other lines in the soybean collection that demonstrate resistance to leaf-feeding insects are PI 171451, PI 227687 and PI 229358.

These lines have been used to develop at least three insect resistant varieties: Crockett, Lamar and Lyon. Scientists at ARS' Soybean Production Research Unit in Stoneville, Miss., say it's important to have more than one line that demonstrates resistance, should one line be wiped out.

Besides insect resistance, the new PI 417061 line contains 44 percent protein. The most widely used source of insect resistance, PI 229358, has only 38 percent. Soybean breeders interested in developing insect-resistant, high-protein cultivars will now have a more desirable parent for this purpose.

The new soybean line also grows more upright--an advantage because plants of many of the other germplasm lines tend to fall over, making them difficult to harvest.

Soybean breeders and researchers may obtain germplasm by contacting Randall Nelson, soy germplasm curator, ARS Plant Physiology and Genetics Research Unit, located at the University of Illinois, Urbana.

Scientific contacts: Thomas Kilen, ARS Soybean Research Unit, Stoneville, Miss., phone (601) 686-3125, fax 686-3140, kilent@ars.usda.gov; and Randall Nelson, ARS Plant Physiology and Genetics Research Unit, University of Illinois Dept. of Agronomy, Urbana, Ill., phone (217) 244- 4346, fax (217) 333-4639, rlnelson@uiuc.edu..