Identification of rust fungi (Pucciniales) on species of Allium in Australia

Collections of rust fungi (Pucciniales) on species of Allium in Australia have previously been identified as Puccinia allii. These identifications are unsatisfactory as P. allii is a species complex that has yet to be taxonomically resolved. Some of the cryptic species in this complex may represent new introductions and have potential biosecurity consequences for Australia. A combined morphological and molecular approach has been used to identify the species of rust on Allium collected in Australia. Three different species of rust, Puccinia alli sensu lato, P. allii sensu Gäumann (1959) and P. mixta, were identified based on the morphology of urediniospores and teliospores, and analyses of the internal transcribed spacer and large subunit regions of nuclear ribosomal DNA. One of these species, P. mixta, may not be established in Australia. The taxonomy of rusts on Allium is discussed