Successful surveillance results in early first detection of Ug99 in South Asia

Successful global wheat disease surveillance and monitoring has resulted in early detection of wheat stem rust Ug99 in Nepal. A combination of vigilant field surveys and sampling by Nepal’s National Plant Pathology Research Centre (NPPRC) and National Wheat Research Program (NWRP), supported by rigorous and accurate disease diagnostics at the Global Rust Reference Center (GRRC), Denmark, resulted in confirmed detection of the Ug99 strain named TTKTT. The long running and sustained surveillance efforts undertaken by NPPRC and NWRP, including off-season surveys, proved vital in the detection of Ug99 in Nepal. Confirmed results were obtained from two field samples collected in early November 2023 from off-season summer wheat crops in Dolakha district, Nepal. Repeated experiments and high quality pathotyping and genotyping at GRRC confirmed the results.

“The combination of molecular genotyping of incoming samples, without prior recovery in our laboratory and independent diagnostic assays of recovered stem rust isolates, confirmed the presence of Ug99 and a highly virulent race variant termed TTKTT,” says professor Mogens Hovmøller, leader of the GRRC at Aarhus University in Denmark.