CALGARY - The Canadian government is trying to reassure Japan and other trading partners that genetically modified wheat found in southern Alberta is limited to a few plants growing along a remote access road and has not been detected in the wider supply.

Japan has temporarily halted imports of Canadian wheat as it reviews the tests that Canadian officials have already done, Global Affairs spokesman Jesse Wilson said in a statement.

“The government of Canada is working with its key trading partners to ensure they have all the necessary information and are relying on science-based evidence to limit market disruption,” he wrote Friday.

The Canadian Food Inspection Agency said Thursday that it tested wheat plants that survived spraying for weeds and found they were genetically modified to tolerate herbicide.

The agency said extensive scientific testing has found the wheat is isolated to the site where it was found and poses no food safety risk.

Such modified wheat is not approved for commercial use in Canada.

“Temporary market closure is a standard protocol for the Japanese,” Wilson said.

“CFIA officials are already in close contact to share data, review evidence and demonstrate full transparency, which is exactly as it should be when it comes to keeping trade open.”

The Japanese embassy in Ottawa said Friday the country's ministry of agriculture, forestry and fisheries temporarily suspended the import tender and sale of Canadian wheat to domestic milling companies in response to the CFIA's announcement.

“The embassy understands that the details with regard to this issue are being worked out between the competent authorities of the two countries,” it said.

The Alberta government said the dozen genetically modified red spring wheat plants were found last fall in a roadside ditch near Strathmore, east of Calgary.

“We're disappointed with Japan's decision to suspend the trade of Canadian wheat, and we are working to provide them with the assurances they need to reopen markets,” Economic Development Minister Deron Bilous said Friday.

Alberta's wheat exports totalled $2.1 billion last year. The top two buyers are the United States, at $280 million a year, followed by Japan at $203 million.

Bilous said the United States has not contacted Canada to express concern but said the province is reaching out to its trading partners regardless.

Kevin Bender, chairman of the Alberta Wheat Commission, said Japan's move is concerning.

“If they stop importing our grain, that's a major blow to our exports of wheat,” he said.

“My hope is that it would be short-lived based on, first of all, Canada's reputation as a high-quality producer of wheat and food, our safety record, the fact that this is an isolated event.”

Japan imported 1.4 million tonnes of wheat from Canada last year and 1.6 million tonnes the year before, said Cam Dahl, president of Cereals Canada.

“Japan is a very good customer,” he said. “More than that, they are a premium customer. They are the highest grade buyer of Canadian wheat in the world.”

Both Bender and Dahl said there has been no indication other countries are contemplating similar moves.

“I am watching Korea very closely as well as China and the EU,” said Dahl.

The CFIA said it isn't sure how the modified wheat came to be on the access road.

That's worrisome to the Canadian Biotechnology Action Network, a coalition of 16 farming, environmental and social justice groups focused on genetic engineering in food.

“We're relieved this is an isolated contamination case but we're concerned that the government couldn't determine how it happened,” said Lucy Sharratt, a co-ordinator with the network. “Without knowing the cause, contamination could happen again.”

The CFIA said it will work with the landowner to monitor the area over the next three years to help prevent any genetically modified wheat from persisting.

- with files from Dean Bennett in Edmonton