The life history of Puccinia striiformis remains a mystery because the alternate host has never been identified. Inoculation of grasses using aeciospores from naturally infected Berberis chinensis and B. koreana resulted in infection on Poa pratensis, producing uredinia typical of stripe rust caused by P. striiformis. Analyses using real-time polymerase chain reaction and DNA sequence confirmed...

Abstract Wheat stem rust epidemics caused by the obligate pathogenic fungus Puccinia graminis f.sp. tritici have historically driven severe yield losses on all wheat growing continents and, after many decades of control, is re-emerging as a disease concern. In 1998, highly virulent race able to overcome 90% world cultivars, Ug99, was identified in Uganda. Since initial detection, pathogen has e...