Ugly wheat rust variants blow around the world

Environment News Service: New and virulent forms of a fungus called stem rust that attacks wheat are spreading quickly across the world, borne by wind beyond the handful of countries in East Africa where they were first identified. But hope emerged today at a global wheat rust symposium in Minneapolis. Scientists said they are close to producing super varieties of wheat that will resist variants of the Ug99 strain of stem rust, while boosting wheat yields by as much as 15 percent.

The original Ug99 was first discovered in 1998 in Uganda. New data to be presented at the symposium this week show that key Ug99 variants have been identified across all of eastern and southern Africa. Scientists say it is only a matter of time before the rust spores travel to India or Pakistan, Australia or the Americas. "We are facing the prospect of a biological firestorm, but it's also clear that the research community has responded to the threat at top speed, and we are getting results in the form of new varieties that are resistant to rust and appealing to farmers," said Ronnie Coffman, who heads the Durable Rust Resistance in Wheat project at Cornell University, which is coordinating the fight against the disease.

"But the job of science is not over," Coffman said at the symposium. "Declining support for public agricultural research got us into this problem with Ug99. Unless that changes, the problem is likely to arise again in a few years. We are dealing with a constantly-evolving pathogen, and we need to stay at least one step ahead of it at all times."

Coffman and his colleagues warn that significant obstacles must be overcome before the new varieties of wheat can replace susceptible varieties that cover most of an estimated 225 million hectares (556 million acres) of wheat fields across the breadbaskets of South Asia, the Middle East, China, Europe, Australia and North America. "Now it's a question of whether nations are willing to invest the political and economic capital necessary for agricultural research to secure the world's wheat supply," Coffman said….

Stripe rust (not Ug99) on a wheat plant, shot by US Agricultural Research Service