Clonality and hybrid origin of the rare Eucalyptus bennettiae (Myrtaceae) in Western Australia
E. Walker A , M. Byrne A B D , B. Macdonald B , D. Nicolle C and J. McComb AA School of Biological Sciences, Murdoch University, Murdoch, WA 6150, Australia.
B Science Division, Department of Environment and Conservation, Locked Bag 104, Bentley Delivery Centre, WA 6983, Australia.
C Currency Creek Arboretum, 15 Rousillion Promenade, Old Reynella, SA 5161, Australia.
D Corresponding author. Email: Margaret.Byrne@dec.wa.gov.au
Australian Journal of Botany 57(3) 180-188 https://doi.org/10.1071/BT08148
Submitted: 13 August 2008 Accepted: 25 May 2009 Published: 29 June 2009
Abstract
Clonality and hybrid origin influence the conservation status of rare and restricted species. Eucalyptus bennettiae Carr & Carr is a rare species known only from a few individuals that may be clonal and may have arisen through hybridisation between other co-occurring species. The hybrid status and clonality of E. bennettiae was investigated with analysis of microsatellite variation in E. bennettiae compared with its putative parents, E. lehmannii subsp. parallela, E. sporadica and E. astringens subsp. redacta, identified through morphological characteristics. Analysis of microsatellite variation revealed clonality with one individual present at each location, and additivity of alleles and no unique alleles in E. bennettiae compared with two of the putative parents, E. lehmannii subsp. parallela and E. sporadica. In addition, E. bennettiae displayed intermediacy in species relationships and measures of relatedness, and assignment tests showed mixed ancestry in relation to these species but not the third putative parent, E. astringens subsp. redacta. These findings confirm that E. bennettiae is a hybrid and evaluation of the taxon for conservation protection shows that it does not satisfy the criteria for listing as a threatened species.
Acknowledgements
We thank David Coates for advice on policy relating to conservation of threatened taxa in Western Australia.
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