Researchers from University of California, Davis, have identified a gene that enables resistance to a new devastating strain of stem rust, a fungal disease that is hampering wheat production throughout Africa and Asia and threatening global food security.

The discovery by UC Davis wheat geneticist Jorge Dubcovsky and his team will help breeders more quickly develop varieties that can fend off the deadly pathogens and halt a worldwide wheat epidemic. The findings were recently published in the journal Proceedings of the National Academy of Sciences. Wheat and stem rust have been in an evolutionary arms race for more than 10,000 years. In the 1950s, a major epidemic of the disease spread through North America and destroyed up to 40 percent of the wheat crop, the world’s second most important grain next to rice. Since then, scientists have developed rust-resistant varieties to boost wheat’s immunity to stem rust. But the pathogens are making a comeback. A new strain of the stem rust - called Ug99 after it was discovered in Uganda in 1999 - is spreading throughout the region. About 90 percent of the wheat varieties grown worldwide are susceptible to Ug99.