Present address: Department of Plant Pathology and Emerging Pathogens Institute, University of Florida, PO Box 110680, Gainesville, FL, 32611, USA.
Phytophthora obscura sp. nov., a new species of the novel Phytophthora subclade 8d
Article first published online: 9 OCT 2011
Published 2011. This article is a US Government work and is in the public domain in the USA
Volume 61, Issue 3, pages 610–622, June 2012
How to Cite
Grünwald, N. J., Werres, S., Goss, E. M., Taylor, C. R. and Fieland, V. J. (2012), Phytophthora obscura sp. nov., a new species of the novel Phytophthora subclade 8d. Plant Pathology, 61: 610–622. doi: 10.1111/j.1365-3059.2011.02538.x
- Issue published online: 9 MAY 2012
- Article first published online: 9 OCT 2011
- Published online 9 October 2011
- Aesculus hippocastanum;
- Kalmia latifolia;
A new Phytophthora species was detected (i) in the USA, infecting foliage of Kalmia latifolia, (ii) in substrate underneath Pieris, and (iii) in Germany in soil samples underneath Aesculus hippocastanum showing disease symptoms. The new species Phytophthora obscura sp. nov. is formally named based on phylogenetic analysis, host range, Koch’s postulates and morphology. Phytophthora obscura is homothallic with paragynous antheridia and semipapillate sporangia. It is genetically closely related to P. syringae and P. austrocedrae and together these three species define a new Phytophthora subclade 8d, with significant support for all genetic loci analysed including seven nuclear genes and the mitochondrial gene coxII. The morphological and ecological characteristics are very similar to P. syringae, and it is likely that P. obscura was not described earlier because it was identified as P. syringae. Artificial inoculations indicated that horse chestnut, kalmia, pieris and rhododendron might be hosts, and Koch’s postulates were confirmed for kalmia from which it was isolated. This pathogen was named after its elusive nature since it has to date rarely been detected in the US and Germany.