ARS Releases New Soybean Disease Defenses

A new soybean variety and a germplasm line that fight off some major crop diseases have been released by Agricultural Research Service scientists. ARS is the U.S. Department of Agriculture’s chief research agency.

Research geneticist Jeffrey M. Tyler of ARS’ Crop Genetics and Production Research Unit in Stoneville, Miss., developed the new variety, called Bolivar, in cooperation with the Mississippi Agricultural and Forestry Experiment Station, Mississippi State, Miss.

In field studies, Bolivar had high seed yield and good plant height in early season plantings, an environment that normally suppresses plant growth. It is adapted to the clay soils of the lower Mississippi River valley and east Mississippi.

Bolivar is also tolerant to Phytophthora rot and resistant to stem canker and soybean cyst nematode race 3. It has moderate resistance to races 2 and 5.

ARS research geneticist Thomas C. Kilen, also with the Stoneville unit, developed and released the new high-yielding soybean germplasm line D95-5246. It is resistant to Phytophthora rot and soybean cyst nematodes races 3 and 14.

The fungus Phytophthora sojae causes Phytophthora rot, a major soybean disease. Millions of soybean bushels are lost each year to this disease.

Soybean cyst nematodes are worm-like pests that eat soybean roots, causing more losses than all other soybean pathogens combined. The nematodes destroyed nearly 16.4 million bushels of soybeans last year. Last year, combined losses from both were estimated at 20 million bushels in 16 southern states.

These two new releases should give farmers another defense against major soybean crop-killers. To date, Stoneville scientists have developed 29 high-yielding soybean varieties and 24 new germplasm lines with improved pest resistance.

Small amounts of seed are available from the scientists for research purposes only.

An in-depth article on soybean research appears in the August issue of Agricultural Research magazine. The story is also on the World Wide Web at:

http://www.ars.usda.gov/is/AR/archive/aug99/soy0899.htm

Scientific contact: Jeffrey M. Tyler and Thomas C. Kilen, ARS Crop Genetics and Production Research Unit, Stoneville, Miss., phone (601) 686-5241, fax (601) 686-5218, jtyler@ag.gov, tkilen@ag.gov.