2026/04/14 by Silvia Germán, Venancio Riella, Richard García +9 · 1 voice
Agricultural and Biological Sciences · #Genetics and Plant Breeding #Plant pathogens and resistance mechanisms #Wheat and Barley Genetics and Pathology
paper · pdf · doi:10.1080/07060661.2026.2644954
openalex publication_date 2026/04/14 · openalex created_date 2026/04/15 · openalex updated_date 2026/07/22
Wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) are Uruguay’s major winter crops. The country’s humid temperate climate favours the development of rust diseases, making rusts some of the most damaging pathogens. This review synthesizes over three decades of research conducted by Uruguay’s National Agricultural Research Institute (INIA) on rust epidemiology, pathogen population dynamics, and breeding for genetic resistance. Wheat leaf rust has been the most prevalent, with 87 Puccinia triticina races identified during 1991–2023, reflecting a highly dynamic population that rapidly overcomes major resistance genes. After many years without epidemics, severe wheat stem rust outbreaks occurred in 2014–2015, caused by races distinct from the Ug99 race group, while wheat yellow rust re-emerged in 2017 due to the incursion of aggressive P. striiformis f.sp tritici lineages (PstS7, PstS10, PstS13) likely introduced from Europe. The P. hordei population has remained relatively stable, with only three races identified since 1991. INIA’s breeding programs have progressively shifted from major-gene resistance toward quantitative adult-plant resistance and marker-assisted pyramiding of effective major genes. The integration of long-term pathogen surveillance, molecular diagnostics, and precise field phenotyping has been pivotal for improving genetic resistance. Continued regional monitoring and pre-emptive breeding are essential to mitigate the evolving rust threat across the largest South American epidemiological zone.