Taxonomy and identification of Septoria and Stagonospora species on small-grain cereals

Numerous significant changes have been made in the taxonomy of both the ana morphs and teleomorphs of the Septoria group of leaf spot pathogens on smal l grain cereals during the past 30 years. The pathogens fall into two relat ed but distinct groups, with anamorphic genera now placed in Septoria and S tagonospora of the Sphaeropsidales. Each of these genera has distinct teleo morphs in the Loculoascomycetes in Mycosphaerella and Phaeosphaeria. These reclassifications were based largely on fungal morphology and host pathogen icity as originally characterized. Recent studies have investigated the phy logenetic relationships among these species using the techniques of molecul ar genetics, and have related molecular characteristics to taxonomy based o n classical morphology. A clearer understanding of the taxonomy of this gro up will enhance our ability to diagnose and manage these important cereal p athogens.