Researchers at the University of California, Davis, have discovered a gene that creates resistance to stem-rust — a fungus that threatens wheat crops in Africa and Asia and food security worldwide.
“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,” explains Phys.org. “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.”
The UC Davis team has identified three forms of Sr13, a gene found in pasta wheat, that is resistant to Ug99 and another group of damaging stem-rust strains from Yemen and Ethiopa. The same team discovered a different stem-rust resistant gene in 2013 and say they are poised to uncover a third that offers protection.
“Ug99 has expanded to most of the wheat-growing regions in Africa and has crossed the Red Sea to Yemen and Iran,” said wheat geneticist Jorge Dubcovsky, who coauthored the study, published in the journal Proceedings of the National Academy of Sciences. “Ug99 is now at the door of the Punjab region—the bread basket of Asia—and identification and deployment of effective resistance genes are critical to mitigate this threat.”