ARS | Publication request: SPECIES DELIMITATION IN THE PUCCINIA STRIIFORMIS COMPLEX

Submitted to: Mycological International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 12, 2002
Publication Date: N/A

Technical Abstract: Puccinia striiformis (Uredinales), the cause of yellow rust or stripe rust, is a species forming uredinia and telia on various species of Poaceae. It is assumed to be heteroecious, but the aecial host is not known. Currently, two varieties, P. striiformis var. striiformis and P. striiformis var. dactylidis are accepted by most authors. We sequenced the variable internal transcribed spacer (ITS 1+2) region and the more conservative 5.8S gene of the ribosomal DNA and found considerable differences among specimens on Triticum (Triticae), Dactylis glomerata (Poae) and Poa pratensis (Poae). These results correspond with a previous isozyme phenotype study and also with analyses of morphological features. Based on these differences we suggest a three-species system including P. striiformis on numerous hosts (mainly on Triticeae), P. pseudostriiformis sp. nov. on Poa pratensis (Poae), and P. striiformioides nom. et stat. nov. on Dactylis glomerata (Poae).