U.S. officials raced to quell global alarm on [May 30] over the first-ever discovery of an unapproved strain of genetically modified wheat, working to figure out how the rogue grain escaped from a field trial a decade ago. In the wake of news that a strain developed by biotech giant Monsanto Co had been found in an Oregon field late last month, major buyer Japan cancelled plans to buy U.S. wheat while the Europe Union said it would step up testing. Worried U.S. farmers wondered if their own fields had been contaminated. Even after weeks of investigation, experts are baffled as to how the seed survived for years after Monsanto had ceased all field tests of the product. It was found in a field growing a different type of wheat than Monsanto's strain, far from areas used for field tests, according to an Oregon State University wheat researcher who tested the strain. The discovery threatens to stoke consumer outcry over the possible risk of cross-contaminating natural products with genetically altered foods, and may embolden critics who say U.S. regulation of GMO products is lax. It is all the more alarming because the wheat strain was thought to have been eliminated after test trials ended in 2005, as Monsanto abandoned efforts to secure regulatory approval due to worldwide opposition. While there have been more than 20 major violations of U.S. regulations on handling or co-mingling biotechnology crops, none have ever involved wheat before. Some analysts feared a potentially damaging blow to the $8 billion wheat export business, recalling the more than yearlong disruption to corn sales following a similar discovery in 2000.