Morphological and molecular characterisation of Puccinia lagenophorae , now present in central North America

In June 2004, a rust fungus not previously reported for Oklahoma was found occurring naturally on the weed, common groundsel, Senecio vulgaris , in pots in a commercial container nursery in northeastern Oklahoma. Host symptoms and morphology of teliospores and aeciospores of the fungus were consistent with those of Puccinia lagenophorae , a recent introduction into North America that has, as yet, been reported only on the East and West Coasts of the USA. This is the first report of the rust in central regions of North America. The rust is believed to be native to Australia and New Zealand and subsequently reported in most continents on numerous species and genera of the Asteraceae. Some authors in Europe consider the rust on Bellis as different from the one on Senecio , naming it Puccinia distincta . Our ITS1‐5.8S‐ITS2 ribosomal DNA sequence data, however, show homology with P. distincta sequences from Europe, indicating there is only one morphologically‐variable polyphagous species. Presumably, the rust was introduced into Oklahoma on infected plants from the West Coast of the USA, the source of most plant material in the commercial nursery where it was found. The rust is potentially important on several ornamental Asteraceae in North America as it has become in Europe, where it spreads rapidly throughout that continent following its introduction there in the early 1960s.