New Study Reveals Genetic Roots of Resistance to Wheat Disease

A new study conducted by researchers from the University of Nebraska-Lincoln (UNL) has revealed the genetic roots of resistance to wheat stem rust, a disease that has recently devastated crop yields from southern Africa through the Middle East. Plant breeders have successfully combated the disease by introducing rust-resistant cultivars in the mid-20th century, until Ug99, a mutated strain emerged in 1999 in Uganda.

A hardy wheat variety, Gage, has Sr2, a rare resistant gene against Ug99. In the recently published study led by P. Stephen Baenziger of UNL, the researchers isolated and examined DNA sequences of Gage to ascertain its resistance to stem rust, including Ug99, than other cultivars featuring the Sr2 gene. They concluded that Gage's rust-resistance at maturity is likely from a combination of Sr2 and an additional gene, which the team believes also contributes resistance at the seedling stage. The team has narrowed down the location and potential identity of this additional gene, which they hope to verify soon.

"It so happens that the source of Sr2 that was used to create Gage — the variety Hope — actually had a number of other stem rust resistance genes in it. Our results would say that it looks like Gage got the lucky straw, so to speak, from Hope," said Baenziger.

For more details, read the news release at the UNL website.