Susan Rutherford1,2, Trevor C Wilson2, Jia-Yee Samantha Yap2, Enhua Lee3, Graeme Errington4, Maurizio Rossetto2. 1. Institute of Environmental Health and Ecological Security, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, P. R. China. 2. Research Centre for Ecosystem Resilience, Australian Institute of Botanic Science, Royal Botanic Garden Sydney, Sydney, Australia. 3. Biodiversity and Conservation Division, New South Wales Department of Planning and Environment, Sydney, Australia. 4. Australian PlantBank, Australian Institute of Botanical Science, Australian Botanic Garden, Mount Annan, New South Wales, Australia.
Abstract
BACKGROUND AND AIMS: Knowledge of the evolutionary processes responsible for the distribution of threatened and highly localized species is important for their conservation. Population genomics can provide insights into evolutionary processes to inform management practices, including the translocation of threatened plant species. In this study, we focus on a critically endangered eucalypt, Eucalyptus sp. Cattai, which is restricted to a 40-km2 area of Sydney, Australia, and is threatened by increased urbanization. Eucalyptus sp. Cattai has yet to be formally described in part due to its suspected hybrid origin. Here, we examined evolutionary processes and species boundaries in E. sp. Cattai to determine whether translocation was warranted. METHODS: We used genome-wide scans to investigate the evolutionary relationships of E. sp. Cattai with related species, and to assess levels of genetic health and admixture. Morphological trait and genomic data were obtained from seedlings of E. sp. Cattai propagated in a common garden to assess their genetic provenance and hybrid status. KEY RESULTS: All analyses revealed that E. sp. Cattai was strongly supported as a distinct species. Genetic diversity varied across populations, and clonality was unexpectedly high. Interspecific hybridization was detected, and was more prevalent in seedlings compared to in situ adult plants, indicating that post-zygotic barriers may restrict the establishment of hybrids. CONCLUSIONS: Multiple evolutionary processes (e.g. hybridization and clonality) can operate within one rare and restricted species. Insights regarding evolutionary processes from our study were used to assist with the translocation of genetically 'pure' and healthy ex situ seedlings to nearby suitable habitat. Our findings demonstrate that it is vital to provide an understanding of evolutionary relationships and processes with an examination of population genomics in the design and implementation of an effective translocation strategy.
BACKGROUND AND AIMS: Knowledge of the evolutionary processes responsible for the distribution of threatened and highly localized species is important for their conservation. Population genomics can provide insights into evolutionary processes to inform management practices, including the translocation of threatened plant species. In this study, we focus on a critically endangered eucalypt, Eucalyptus sp. Cattai, which is restricted to a 40-km2 area of Sydney, Australia, and is threatened by increased urbanization. Eucalyptus sp. Cattai has yet to be formally described in part due to its suspected hybrid origin. Here, we examined evolutionary processes and species boundaries in E. sp. Cattai to determine whether translocation was warranted. METHODS: We used genome-wide scans to investigate the evolutionary relationships of E. sp. Cattai with related species, and to assess levels of genetic health and admixture. Morphological trait and genomic data were obtained from seedlings of E. sp. Cattai propagated in a common garden to assess their genetic provenance and hybrid status. KEY RESULTS: All analyses revealed that E. sp. Cattai was strongly supported as a distinct species. Genetic diversity varied across populations, and clonality was unexpectedly high. Interspecific hybridization was detected, and was more prevalent in seedlings compared to in situ adult plants, indicating that post-zygotic barriers may restrict the establishment of hybrids. CONCLUSIONS: Multiple evolutionary processes (e.g. hybridization and clonality) can operate within one rare and restricted species. Insights regarding evolutionary processes from our study were used to assist with the translocation of genetically 'pure' and healthy ex situ seedlings to nearby suitable habitat. Our findings demonstrate that it is vital to provide an understanding of evolutionary relationships and processes with an examination of population genomics in the design and implementation of an effective translocation strategy.
Authors: Susan Rutherford; Maurizio Rossetto; Jason G Bragg; Hannah McPherson; Doug Benson; Stephen P Bonser; Peter G Wilson Journal: Heredity (Edinb) Date: 2018-04-10 Impact factor: 3.821
Authors: Andrew R Weeks; Carla M Sgro; Andrew G Young; Richard Frankham; Nicki J Mitchell; Kim A Miller; Margaret Byrne; David J Coates; Mark D B Eldridge; Paul Sunnucks; Martin F Breed; Elizabeth A James; Ary A Hoffmann Journal: Evol Appl Date: 2011-06-18 Impact factor: 5.183