DNA studies of the Restionaceae

Dr Barbara Briggs, Honorary Research Associate & Dr Adam Marchant, Senior Technical Officer 

Continuing their studies on Restionaceae, Dr Adam Marchant and Dr Barbara Briggs assembled sequence data from chloroplast DNA from further species. Assisted by Dr Andrew Perkins, they developed phylogenies showing the relationships between Australian genera and species and considered the status of the group of diminutive plants known as the Centrolepidaceae. The findings suggest that the Centrolepidaceae should be regarded as a subgroup of the Restionaceae, rather than a separate, but related, family. The work involved interpreting (often discordant) results from different genes and different methods of analysis in these plant groups which have exceptionally fast rates of evolutionary change in their DNA. A paper on their findings was prepared for presentation at the Monocots IV conference in Copenhagen.

Since three robustly supported clades are apparent within Restionaceae, Dr Briggs and Professor Peter Linder of the University of Zurich intend to recognize these as subfamilies. They have prepared descriptions of two new Australian subfamilies of Restionaceae to provide names for these major groups. A name already exists for the one African subfamily of Restionaceae and also for the Centrolepidaceae clade if this is included within Restionaceae.

Basal Angiosperms - Hydatellaceae

Studies of the Hydatellaceae, which was previously referred to as the Poales, led to cooperation by Honorary Research Associate Dr Barbara Briggs with Dr P. J. Rudall of Royal Botanic Gardens Kew and Drs D. Sokoloff and M. Remizowa of Moscow State University, on the morphology of inflorescences of this family, and its relationships with other Nymphaeales. The Hydatellaceae are a small family of diminutive aquatic plants, most of them native in Australia. Dr Briggs collected specimens of Hydatella in Tasmania which are also being used in studies at the University of Florida of gene sequences of entire plastids by Drs P.S. and D. Soltis with Dr Michael J. Moore.

Meeboldina crassipes (Restionaceae) a West Australian species in habitats that are wet in winter but dry out in summer. DNA studies are showing relationships among species of this Southern Hemisphere plant family. Photo: B Briggs