Biotech Updates

New Strategy to Control Stem Rust

December 23, 2010

Stem rust has been and still is a devastating disease of wheat worldwide. Its initial discovery and spread in the 1950s was controlled by the development of resistant varieties at that time. A new race of stem rust named Ug99 was discovered in 1999 in Uganda, in which the previously used resistance is no longer effective.

In efforts to overcome this new stem rust strain, scientists at the University of California-Davis, Kansas State University and the USDA Cereal Disease Laboratory in Minnesota have mapped and characterized resistance gene Sr35. Molecular markers and candidate genes associated with the gene can be used to accelerate the development of wheat varieties with Sr35 gene. Stable resistance against Ug99 can be achieved however with a deployment of the Sr35 gene with other resistance genes.

According to Jorge Dubcovsky, the author of the study, "The presence of multiple resistance genes is expected to extend the durability of resistance, since the probability of simultaneous mutations in the pathogen to overcome multiple resistance mechanisms is much lower than the probability to overcome individual mutations."

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