First report of Puccinia graminis f. sp. tritici races with virulence to wheat stem rust resistance genes Sr31 and Sr24 in Eritrea

Identification of wheat stem rust (Puccinia graminis f. sp. tritici) isolate Ug99 has raised international concern. Since initial detection, seven races have been identified in the Ug99 lineage and occurrence is confirmed in nine countries. During rust surveys of Eritrea in 2010, stem rust was widespread in the highland wheat growing areas. Stem rust samples were analyzed for race identity and identified as TTKST (four isolates) and PTKST (five isolates). Both races belong to the Ug99 lineage and both exhibit combined Sr31 and Sr24 virulence. This first confirmation of TTKST and PTKST in Eritrea is important as it represents further geographical spread of Ug99-related races. Based on postulated migration routes of the original Ug99, the confirmed presence of TTKST and PTKST in Eritrea increases the possibility for range expansion out of Africa by crossing the Red Sea and into the Arabian Peninsula. Future spread of TTKST and PTKST to western Asia is considered highly likely.; Identification of wheat stem rust (Puccinia graminis f. sp. tritici) isolate Ug99 has raised international concern. Since initial detection, seven races have been identified in the Ug99 lineage and occurrence is confirmed in nine countries. During rust surveys of Eritrea in 2010, stem rust was widespread in the highland wheat growing areas. Stem rust samples were analyzed for race identity and identified as TTKST (four isolates) and PTKST (five isolates). Both races belong to the Ug99 lineage and both exhibit combined Sr31 and Sr24 virulence. This first confirmation of TTKST and PTKST in Eritrea is important as it represents further geographical spread of Ug99-related races. Based on postulated migration routes of the original Ug99, the confirmed presence of TTKST and PTKST in Eritrea increases the possibility for range expansion out of Africa by crossing the Red Sea and into the Arabian Peninsula. Future spread of TTKST and PTKST to western Asia is considered highly likely.