Enhancing Wheat Resistance: Traditional Varieties Combat Yellow Rust

Wheat production faces a formidable challenge from yellow rust, a fungal disease caused by the pathogen *Puccinia striiformis f. sp. tritici*. Researchers at the University of Zurich (UZH) have identified traditional wheat varieties from Asia that possess multiple resistance-conferring genes, which may prove crucial in developing future commercial wheat varieties resistant to this disease. This discovery highlights the importance of maintaining genetic diversity to ensure food security worldwide.

Yellow rust is notorious for affecting approximately 88% of global bread wheat production, leading to significant yield losses. The urgency to find effective strategies against this pathogen has never been more critical. Professor Kentaro Shimizu, a leading researcher at UZH’s Department of Evolutionary Biology and Environmental Studies, emphasized the potential of these genetic discoveries. "If such genes can be transferred to commercial wheat varieties, they could be instrumental in combating yellow rust," Shimizu stated in a press release dated June 16, 2025.

The focus on high-yielding wheat varieties over the decades has inadvertently narrowed the genetic base of modern crops, making them more susceptible to diseases and environmental stresses. In contrast, traditional wheat varieties, cultivated by farmers across various regions, exhibit a broader genetic diversity that could be harnessed to enhance disease resistance. Katharina Jung, a doctoral researcher at UZH, conducted field trials in collaboration with the International Maize and Wheat Improvement Center (CIMMYT) and Kyoto University. Her research spanned traditional and modern wheat varieties from countries such as Japan, China, Nepal, and Pakistan.

During her research, Jung uncovered two previously uncharacterized genomic regions linked to yellow rust resistance, one from a traditional variety in Nepal and the other prevalent among varieties from southern Himalayan regions. These findings suggest that traditional wheat varieties from these areas may harbor unique and stable resistances to yellow rust, a hypothesis supported by the historical context that the southern Himalayan region is believed to be the origin of the yellow rust pathogen.

The implications of this research extend beyond genetic discovery. It underscores the necessity of conserving local wheat varieties and farming practices, which have been maintained by farmers for generations. "Traditional varieties must be preserved both in gene banks and in farmers' fields to prevent their extinction. Their continued use should involve collaboration with local communities, whose knowledge has significantly contributed to the genetic diversity we observe today," Jung noted.

This project benefited significantly from collaboration with Kyoto University, which provided essential wheat varieties for the research. Shimizu remarked on the value of such partnerships, stating, "I cannot emphasize enough how valuable collaboration is in making scientific progress."

In conclusion, as global food production increasingly faces threats from climate change and disease, the role of traditional wheat varieties emerges as a vital component in ensuring food security. Future research must focus on integrating these varieties into commercial breeding programs, thereby safeguarding agricultural biodiversity and enhancing the resilience of wheat crops against emerging threats. The ongoing collaboration between institutions like UZH and Kyoto University signifies a proactive approach to combating agricultural challenges through research and innovation.