A new geographic record of Olpidiopsis feldmanni infecting the tetrasporophytic stage of Asparagopsis sp. from the Adriatic Sea, confirmed through morphological identification, allowed us to expand previous observations of this organism. Ultrastructural investigations of environmental material showed a large central vacuole and a cell wall thicker than previously reported from other basal oomycete pathogens of algae. Phylogenetic analysis closely associates O. feldmanni to Olpidiopsis bostrychiae concurrent with structural observations. This constitutes the first genetic characterisation of an Olpidiopsis species that was initially described before 1960, adding to the genetic data of three other marine Olpidiopsis species established and genetically characterised since the millennium. The paper discusses concurrences of the ultrastructural observations made here and in previous studies of the marine Olpidiopsis species with those made on the freshwater studies.
Bibliographical noteDate of Acceptance: 14/09/2015
Acknowledgements. We are grateful to the Total Foundation (Paris) for its funding support to this study, to the UK Natural Environment Research Council (NERC) for a doctoral fellowship to K.F. and to the MASTS pooling initiative (Marine Alliance for Science and Technology for Scotland, funded by the Scottish Funding Council and contributing institutions; grant reference HR09011).
- central vacuole
- cyochrome oxidase subunit II
- SSU rRNA
- transmission electron microscopy
- Adriatic Sea