Arsenal from Science Helps the Soybean Combat
Two Powerful Fungal EnemiesBy
October 6, 1997
Farmers have powerful new weapons against fungal pathogens that
destroy soybeans, thanks to scientists at the
Agricultural Research Service. New
soybean lines and a better understanding of the disease process promise to
reduce crop losses to fungal disease.
Phytophthora sojae causes one of soybeans' most serious
diseases--Phytophthora root rot, that can cut yields up to 25 percent. Sudden
death syndrome, (SDS), another soybean disease, is caused by a toxin-producing
form of the fungus Fusarium solani.
After 30 years of research, ARS plant pathologist Scott Abney has
become an expert on the genetics and virulence of both fungal pathogens. At
Production and Pest Control Research Unit, West Lafayette, Ind., Abney
studies the interaction between host plants and fungal parasites to identify
the plants' inherent disease resistance.
Details of Abney's research are described in the October issue of
Agricultural Research magazine. The story can also be seen on the World
Wide Web at:
The data collected by Abney and his colleague, geneticist James R.
Wilcox, has resulted in 14 new soybean varieties with improved resistance to
fungal diseases. All 14 were released to commercial breeders.
Abney's work on the Phytophthora fungus focuses on soybean
"Rps" genes. These genes trigger production of an antifungal compound,
phytoalexin, that protects the plant from the fungus. Abney also discovered
seven new Phytophthora races and identified two additional Rps genes
breeders can use.
In other research, Abney confirmed that F. solani causes
SDS and revealed new, complex host-parasite interactions. He also observed that
highly virulent isolates of the fungus produce a rare Nectria sexual
stage--a discovery that could lead to better strategies for reducing fungus
Scientific contact: T. Scott Abney, ARS
Production and Pest Control Research Unit, West Lafayette, Ind., phone
(765) 494-9859, fax 494-0363, email@example.com.