

Trying to Blight a Fungus with Biotechnology
By Marcia
Wood February 19, 1997California scientists will scrutinize an experimental potato hybrid that may
contain genes for resistance to a new, more virulent strain of a disease called
late blight. The new strain has recently shown up in the U.S. Caused by the fungus Phytophthorainfestans, late blight is
the most destructive disease of potatoes worldwide. The scientists are with USDAs
Agricultural Research Service in Albany,
Calif., and Dry Creek Laboratories, Inc., of Modesto, Calif. The aim is to
speed discovery of genes to protect crops from harmful fungi before and after
harvest. The work is being done under a cooperative research and development
agreement beween the company and ARS. ARS scientist John P. Helgeson in Madison, Wis., developed the hybrid by
fusing leaf cells from a late-blight-resistant species of wild potato with leaf
cells from a cultivated potato variety. If the California researchers find and clone a resistance gene, they intend
to transfer it to commercial potato varieties. Later experiments could reveal whether this potato gene can safeguard other
crops from their worst fungal nightmares. Grapevines, for example, are
continually threatened by the Uncinula necator fungus that causes
powdery mildew. And walnut trees could benefit from a new source of resistance
to Phytophthora fungi that cause root and crown rots. Scientific contact: William R. Belknap, USDA-ARS
Western Regional Research
Center, Albany, Calif. 94710, phone (510) 559-6072 Story contacts Marcia A Wood U.S. Department of Agriculture | |