For. Path. doi: 10.1111/j.1439-0329.2011.00755.x Ó 2011 Blackwell Verlag GmbH Potential susceptibility of Australian flora to a NA2 isolate of Phytophthora ramorum and pathogen sporulation potential By K. B. Ireland1,2,7,D.Hu¨ berli2,3, B. Dell2,4, I. W. Smith5, D. M. Rizzo6 and G. E. St. J. Hardy1,2 1Cooperative Research Centre for National Plant Biosecurity, PO Box 5012, Bruce, 2617, ACT, Australia; 2Centre for Phytophthora Science and Management, School of Biological Sciences and Biotechnology, Murdoch University, South St, Murdoch 6150, WA, Australia; 3Crop Protection, Department of Agriculture and Food, Western Australia, 3 Baron-Hay Court, South Perth, WA, Australia; 4Sustainable Ecosystems Research Institute, Murdoch University, Perth, WA, Australia; 5Department of Forest and Ecosystem Science, University of Melbourne, 500 Yarra Boulevard, Richmond, Vic., Australia; 6Department of Plant, Pathology, University of California, 1 Shields Avenue, Davis, CA, USA; 7E-mail:
[email protected] (for correspondence) Summary Phytophthora ramorum is an invasive plant pathogen and the cause of considerable and widespread damage in nurseries, gardens and natural woodland ecosystems of the USA and Europe. It is considered to be a significant plant disease as it could cause biodiversity loss and severe economic losses in plant industries in areas where it is not yet known to exist, such as Australasia. Foliar susceptibility and sporulation potential were tested using detached-leaf assays for 70 Australian native plant species sourced from established gardens and arboreta in California using a NA2 isolate of P. ramorum. Correa ÔSister DawnÕ, Eucalyptus regnans, Isopogon cuneatus, I. formosus, Leptospermum scoparium, L.