Annals of Botany Page 1 of 11 doi:10.1093/aob/mcx022, available online at https://academic.oup.com/aob Genomic diversity guides conservation strategies among rare terrestrial orchid species when taxonomy remains uncertain Collin W. Ahrens1,2,*, Megan A. Supple3, Nicola C. Aitken3, David J. Cantrill1, Justin O. Borevitz3 and Elizabeth A. James1 1Royal Botanic Gardens Victoria, Science Division, Melbourne, Victoria 3004, Australia, 2Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia and 3Australian National University, Research School of Biology, Centre of Excellence in Plant Energy Biology, Canberra, ACT 0200, Australia *For correspondence. E-mail
[email protected] Received: 21 January 2017 Editorial decision: 30 January 2017 Accepted: 12 February 2017 Background and Aims Species are often used as the unit for conservation, but may not be suitable for species complexes where taxa are difficult to distinguish. Under such circumstances, it may be more appropriate to consider species groups or populations as evolutionarily significant units (ESUs). A population genomic approach was em- ployed to investigate the diversity within and among closely related species to create a more robust, lineage-specific conservation strategy for a nationally endangered terrestrial orchid and its relatives from south-eastern Australia. Methods Four putative species were sampled from a total of 16 populations in the Victorian Volcanic Plain (VVP) bioregion and one population of a sub-alpine outgroup in south-eastern Australia. Morphological measure- ments were taken in situ along with leaf material for genotyping by sequencing (GBS) and microsatellite analyses. Key Results Species could not be differentiated using morphological measurements.