US PREPARATIONS FOR POTENTIAL INTRODUCTION OF Ug99 STRAINS OF WHEAT STEM RUST

DOI: 10.1564/20aug02Wheatstemrust,causedbyPucciniagraminisf.sp.tritici,ispresentandathreattoproductionwhereverwheat,barley,andothersmallgrainsaregrown. In1999,anew,morevirulentstrainofthisfungus,knownasUg99,wasconfirmedinUgandaandKenya. Thenewstrainhasthecapabilitytoovercome the most widely used and effective stem rustresistancegenes. ThisnewpathogenstrainhassincebeenfoundandconfirmedinEthiopia,Yemen,andrecentlyIran.To mitigate yield losses, effective management, andprotectionplansneedtobedevelopedandimplementedassoonaspossible. ThisarticlesummarizesthecoordinatedapproachbeingtakenintheUStoaddressthepossibleappearanceofUg99anditsvariantsonwheatandbarley.