Molecular characterisation of a Phytophthora 'hybrid swarm' in native ecosystems and waterways in Western Australia

Burgess, T., Stukely, M., Hardy, G.E.S.J., Hüberli, D., White, D. and Jung, T. (2011) Molecular characterisation of a Phytophthora 'hybrid swarm' in native ecosystems and waterways in Western Australia. In: Asian Association of Societies for Plant Pathology (AASPP) and the Australasian Plant Pathology Society Conference, 26 - 29 April, Darwin, Australia.

Abstract

During surveys of dying vegetation in natural ecosystems and associated waterways in Western Australia many new taxa have been identified and subsequently described. Additionally from within Phytophthora ITS Clade 6, a huge array of natural hybrids all containing numerous single base pair polymorphisms have been isolated. In phylogenetic analyses, the hybrids cluster most closely with the newly described sterile species P. thermophila prov. nom. and P. litoralis prov. nom. For representative hybrid isolates, the region spanning the internal transcribed spacer region of the ribosomal DNA (ITS), the heat shock protein 90 and the mitochondrial coxI gene were amplified, cloned and sequenced. The hybrids are not the result of a simple hybridisation event between two parent species, rather there is evidence of a hybrids swarm with hybridisation not only between parent species, but also between hybrids. Results from the molecular analysis of these hybrids will be presented.