WRAPUP 2-U.S. probes source of GMO wheat in Oregon; importers suspend orders
* South Korea testing U.S. wheat and flour supplies at weekend
* Other Asian nations step up inspections
* U.S. says no evidence rogue grain has entered supply chain
* Price impact concentrated on U.S. Pacific Northwest crops
By Charles Abbott and Meeyoung Cho
WASHINGTON/SEOUL, May 31 (Reuters) - Two days after news that genetically modified wheat had been found growing in Oregon, U.S. officials said they were no closer to knowing how it appeared, while South Korea joined Japan in suspending some U.S. wheat purchases.
A top official with the U.S. Department of Agriculture said Friday that investigators were "pursuing many avenues" to determine how the wheat - which carries a gene making it resistant to herbicide - popped up in late April.
Although the United States has embraced genetically modified crops such as soybeans and cotton, genetically modified wheat has never been approved in the United States, or anywhere else in the world.
"We have not ... eliminated any" potential causes, said Bernadette Juarez, deputy director of the investigative unit with USDA's Animal and Plant Health Inspection Service. Continued...