Scientists have reported that variants of the Ug99 strain of stem rust are becoming increasingly virulent and are being carried by wind beyond the few countries in East Africa where the stem rust was originally identified. This was a topic of discussion June 13 beginning a global wheat rust symposium in Minneapolis.
The huge threat of Ug99 was identified more than five years ago, and efforts have been focused on limiting its spread while also finding methods to combat this highly deadly form of wheat rust. There has been much fear that Ug99 strains of rust will eventually span the globe moving mainly by wind across large expanses of ocean, even from Africa to the U.S.
But at the Borlaug Global Rust Initiative symposium, scientists expressed confidence in breeding varieties of wheat that will resist the potent pathogen, while also boosting yield potential of wheat planted in Africa by as much as 15 percent.
Exactly when depends on a lot of variables and continued success in plant breeding technology. There are significant obstacles that have to be overcome before new varieties of wheat can replace susceptible varieties. Biotech wheat has not been pushed as the prime method of solving the problem.
"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 (DRRW) project at Cornell University, which is coordinating the fight against the disease. "But the job of science is not over. 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 provided his view on the strong effort to beat the threat and the lack of research funding to Food Ingredients First.com
"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 added.
The move to protect the world’s wheat production from Ug99 is focused on conferring genetic resistance in wheat and transferring these traits to local varieties in all the growing areas of the world, the scientists at the symposium explained.
There are some promising results out of breeding research in Mexico, Kenya, Ethiopia and the U.S. Going forward this week, scientists connected to the International Maize and Wheat Improvement Center in Mexico will report on new varieties of wheat under development that have resistance to three major wheat rusts—stem rust, yellow rust and leaf rust.
Time is noted as being a limiting factor because moving from the research lab to mass seed production can be a drawn out process that also requires seed company and government commitment. Farmers in Africa and other undeveloped countries also will not have the money to replace their old wheat varieties with new ones as they become available, which is necessary to quickly put a stop to the Ug99 threat.
David Hodson, with the Global Cereal Rust Monitoring System at the Food and Agriculture Organization of the United Nations (FAO), is presenting information on Ug99’s spread. He said there are now more than 20 countries contributing data to the Ug99 surveillance and monitoring system, compared to only two in 2007, and 10 more countries could become contributors shortly.
In conjunction with Ug99, the pathogen of yellow rust is a topic being addressed at the symposium, too. New data is being presented that shows yellow rust is now common in the world's wheat-growing regions of the Middle East and Africa, and this rust can cause up to 40 percent yield losses. Yellow rust is no small concern, but it is not the threat being focused on the most.