First Large-Scale Breakdown of Yr15 Resistance to Wheat Yellow Rust (Puccinia striiformis f. sp. tritici) Recorded Globally

The United Kingdom Cereal Pathogen Virulence Survey (UKCPVS) was established in 1967 following a major yellow rust outbreak on the previously resistant wheat variety Rothwell Perdix. Since then, virulence in Puccinia striiformis f. sp. tritici (Pst), the causal agent of yellow rust, has been routinely monitored across the UK.

In late winter to early spring 2025, unusually high levels of yellow rust infections on winter wheat varieties previously rated as highly resistant at both seedling and adult plant stages were observed in the counties of Northumberland and Tyne and Wear (Figure 1a). This indicated a potential major resistance breakdown, a concern soon confirmed by reports from across the agricultural industry.