Context As threatening processes continue to impact rare plant populations, the use of translocat... more Context As threatening processes continue to impact rare plant populations, the use of translocations is becoming increasingly frequent. The ultimate success of translocation, attaining long-term persistence, is determined by species’ ability to reproduce, recruit, and maintain levels of genetic diversity that permits the capacity to adapt to environmental change. Aims This study aimed to assess translocation success of Banksia brownii. Methods We compared genetic diversity, reproductive output and aspects of the mating system of a translocated population with four reference wild populations. Key results We found that the use of multiple source populations for the translocation resulted in levels of genetic diversity comparable to reference populations of high diversity. Reproductive output was highest in the translocated population and a positive relationship between plant size and number of flowers across all populations was evident. However, mating system analysis revealed a larg...
Seagrasses have evolved independently at least four times throughout their evolutionary history. ... more Seagrasses have evolved independently at least four times throughout their evolutionary history. All seagrasses are members of the monocot order Alismatales. A new molecular phylogenetic analysis, applying a molecular clock based on recently redefined fossil evidence, provides a framework for describing the timing and relationships of seagrass lineage evolution. The deeper time phylogenetic history of the marine monocotyledons dates back approximately 105 million years ago (Ma) to an ancestor from which two significant lineages evolved more recently. The marine Hydrocharitaceae (Enhalus, Thalassia and Halophila) are a tropical globally distributed lineage which include Australian endemic species of Halophila. The Cymodoceaceae lineage and the Zosteraceae/Potamogetonaceae diverged some ~67 Ma but in each lineage the genera arose more recently. Most seagrass species appear to have evolved in the last ~5 Ma, some more recently. The extant distribution of species will not be the result of vicariance but of long distance connectivity at a global scale. The most significant implication of these results to global biogeography is that there must have been, and likely continues to be, ongoing long distance dispersal leading to the current widespread distributions of species and congeners. The Australian seagrass flora represents all the major evolutionary lineages of seagrasses except the northern hemisphere Phyllospadix, a major clade of Zostera and some of the forms of Halophila. Pollination efficiency is a significant potential driver in the evolution of filiform pollen, and is likely associated with the single seeded fruit in water pollinated species of seagrass in the lineages of seagrass that exhibit this character.
Metabarcoding has improved the way we understand plants within our environment, from their ecolog... more Metabarcoding has improved the way we understand plants within our environment, from their ecology and conservation to invasive species management. The notion of identifying plant taxa within environmental samples relies on the ability to match unknown sequences to known reference libraries. Without comprehensive reference databases, species can go undetected or be incorrectly assigned, leading to false positive and negative detections. To improve our ability to generate reference sequence databases we developed a targeted capture approach using the OZBaits_CP V1.0 set, designed to capture chloroplast gene regions across the entirety of flowering plant diversity. We focused on generating a reference database for coastal temperate plant species given the lack of reference sequences for these taxa. Our approach was successful across all specimens with a target gene recovery rate of 92% which was achieved in a single assay (i.e., samples were pooled), thus making this approach much faster and more efficient than standard barcoding. Further testing of this database highlighted 80% of all samples could be discriminated to family level across all gene regions with some genes achieving greater resolution than others – which was also dependant on the taxon of interest. Thus, we demonstrate the importance of generating reference sequences across multiple chloroplast gene regions as no single loci is sufficient to discriminate across all plant groups. The targeted capture approach outlined in this study provides a way forward to achieve this.
PremiseContinental‐scale disjunctions and associated drivers are core research interests in bioge... more PremiseContinental‐scale disjunctions and associated drivers are core research interests in biogeographic studies. Here, we selected a species‐rich Australian plant genus (Calytrix; Myrtaceae) as a case study to investigate these patterns. Species of this endemic Australian starflower genus have a disjunct distribution across the mesic fringes of the continent and are largely absent from the arid center.MethodsWe used high‐throughput sequencing to generate unprecedented resolution and near complete species‐level nuclear and plastid phylogenies for Calytrix. BioGeoBEARS and biogeographic stochastic mapping were used to infer ancestral areas, the relative contributions of vicariance and dispersal events, and directionality of dispersal.ResultsPresent‐day disjunctions in Calytrix are explained by a combination of scenarios: (1) retreat of multiple lineages from the continental center to the more mesic fringes as Australia became progressively more arid, with subsequent extinction in the center as well as (2) origination of ancestral lineages in southwestern Australia (SWA) for species‐rich clades. The SWA biodiversity hotspot is a major diversification center and the most common source area of dispersals, with multiple lineages originating in SWA and subsequently spreading to the adjacent arid Eremaean region.ConclusionsOur results suggest that major extinction, as a result of cooling and drying of the Australian continent in the Eocene–Miocene, shaped the present‐day biogeography of Calytrix. We hypothesize that this peripheral vicariance pattern, which is similar to the African Rand flora, may explain the disjunctions of many other Australian plant groups. Further studies with densely sampled phylogenies are required to test this hypothesis.
Context As threatening processes continue to impact rare plant populations, the use of translocat... more Context As threatening processes continue to impact rare plant populations, the use of translocations is becoming increasingly frequent. The ultimate success of translocation, attaining long-term persistence, is determined by species’ ability to reproduce, recruit, and maintain levels of genetic diversity that permits the capacity to adapt to environmental change. Aims This study aimed to assess translocation success of Banksia brownii. Methods We compared genetic diversity, reproductive output and aspects of the mating system of a translocated population with four reference wild populations. Key results We found that the use of multiple source populations for the translocation resulted in levels of genetic diversity comparable to reference populations of high diversity. Reproductive output was highest in the translocated population and a positive relationship between plant size and number of flowers across all populations was evident. However, mating system analysis revealed a larg...
Seagrasses have evolved independently at least four times throughout their evolutionary history. ... more Seagrasses have evolved independently at least four times throughout their evolutionary history. All seagrasses are members of the monocot order Alismatales. A new molecular phylogenetic analysis, applying a molecular clock based on recently redefined fossil evidence, provides a framework for describing the timing and relationships of seagrass lineage evolution. The deeper time phylogenetic history of the marine monocotyledons dates back approximately 105 million years ago (Ma) to an ancestor from which two significant lineages evolved more recently. The marine Hydrocharitaceae (Enhalus, Thalassia and Halophila) are a tropical globally distributed lineage which include Australian endemic species of Halophila. The Cymodoceaceae lineage and the Zosteraceae/Potamogetonaceae diverged some ~67 Ma but in each lineage the genera arose more recently. Most seagrass species appear to have evolved in the last ~5 Ma, some more recently. The extant distribution of species will not be the result of vicariance but of long distance connectivity at a global scale. The most significant implication of these results to global biogeography is that there must have been, and likely continues to be, ongoing long distance dispersal leading to the current widespread distributions of species and congeners. The Australian seagrass flora represents all the major evolutionary lineages of seagrasses except the northern hemisphere Phyllospadix, a major clade of Zostera and some of the forms of Halophila. Pollination efficiency is a significant potential driver in the evolution of filiform pollen, and is likely associated with the single seeded fruit in water pollinated species of seagrass in the lineages of seagrass that exhibit this character.
Metabarcoding has improved the way we understand plants within our environment, from their ecolog... more Metabarcoding has improved the way we understand plants within our environment, from their ecology and conservation to invasive species management. The notion of identifying plant taxa within environmental samples relies on the ability to match unknown sequences to known reference libraries. Without comprehensive reference databases, species can go undetected or be incorrectly assigned, leading to false positive and negative detections. To improve our ability to generate reference sequence databases we developed a targeted capture approach using the OZBaits_CP V1.0 set, designed to capture chloroplast gene regions across the entirety of flowering plant diversity. We focused on generating a reference database for coastal temperate plant species given the lack of reference sequences for these taxa. Our approach was successful across all specimens with a target gene recovery rate of 92% which was achieved in a single assay (i.e., samples were pooled), thus making this approach much faster and more efficient than standard barcoding. Further testing of this database highlighted 80% of all samples could be discriminated to family level across all gene regions with some genes achieving greater resolution than others – which was also dependant on the taxon of interest. Thus, we demonstrate the importance of generating reference sequences across multiple chloroplast gene regions as no single loci is sufficient to discriminate across all plant groups. The targeted capture approach outlined in this study provides a way forward to achieve this.
PremiseContinental‐scale disjunctions and associated drivers are core research interests in bioge... more PremiseContinental‐scale disjunctions and associated drivers are core research interests in biogeographic studies. Here, we selected a species‐rich Australian plant genus (Calytrix; Myrtaceae) as a case study to investigate these patterns. Species of this endemic Australian starflower genus have a disjunct distribution across the mesic fringes of the continent and are largely absent from the arid center.MethodsWe used high‐throughput sequencing to generate unprecedented resolution and near complete species‐level nuclear and plastid phylogenies for Calytrix. BioGeoBEARS and biogeographic stochastic mapping were used to infer ancestral areas, the relative contributions of vicariance and dispersal events, and directionality of dispersal.ResultsPresent‐day disjunctions in Calytrix are explained by a combination of scenarios: (1) retreat of multiple lineages from the continental center to the more mesic fringes as Australia became progressively more arid, with subsequent extinction in the center as well as (2) origination of ancestral lineages in southwestern Australia (SWA) for species‐rich clades. The SWA biodiversity hotspot is a major diversification center and the most common source area of dispersals, with multiple lineages originating in SWA and subsequently spreading to the adjacent arid Eremaean region.ConclusionsOur results suggest that major extinction, as a result of cooling and drying of the Australian continent in the Eocene–Miocene, shaped the present‐day biogeography of Calytrix. We hypothesize that this peripheral vicariance pattern, which is similar to the African Rand flora, may explain the disjunctions of many other Australian plant groups. Further studies with densely sampled phylogenies are required to test this hypothesis.
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Papers by Michelle Waycott