Limited phylogeographic and genetic connectivity in Acacia species of low stature in an arid landscape
Abstract Widespread plant species are expected to maintain genetic diversity and gene flow via pollen and seed dispersal. Stature is a key life history trait that affects seed and potentially pollen dispersal, with limited stature associated with limited dispersal and greater genetic differentiation...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2022-07-01
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| Series: | Ecology and Evolution |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/ece3.9052 |
| _version_ | 1818041616733044736 |
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| author | Melissa A. Millar Rachel M. Binks Sarah‐Louise Tapper Bronwyn M. Macdonald Shelley L. McArthur Margaret Hankinson David J. Coates Stephen vanLeeuwen Margaret Byrne |
| author_facet | Melissa A. Millar Rachel M. Binks Sarah‐Louise Tapper Bronwyn M. Macdonald Shelley L. McArthur Margaret Hankinson David J. Coates Stephen vanLeeuwen Margaret Byrne |
| author_sort | Melissa A. Millar |
| collection | DOAJ |
| description | Abstract Widespread plant species are expected to maintain genetic diversity and gene flow via pollen and seed dispersal. Stature is a key life history trait that affects seed and potentially pollen dispersal, with limited stature associated with limited dispersal and greater genetic differentiation. We sampled Hill’s tabletop wattle (Acacia hilliana) and curry wattle (Acacia spondylophylla), two co‐distributed, widespread, Acacia shrubs of low stature, across the arid Pilbara region of north‐western Australia. Using chloroplast sequence and nuclear microsatellite data we evaluated patterns of population genetic and phylogeographic diversity and structure, demographic signals, ratios of pollen to seed dispersal, evidence for historical refugia, and association between elevation and diversity. Results showed strong phylogeographic (chloroplast, GST = 0.831 and 0.898 for A. hilliana and A. spondylophylla, respectively) and contemporary (nuclear, FST = 0.260 and 0.349 for A. hilliana and A. spondylophylla, respectively) genetic structure in both species. This indicates limited genetic connectivity via seed and pollen dispersal associated with Acacia species of small stature compared to taller tree and shrub acacias across the Pilbara bioregion. This effect of stature on genetic structure is superimposed on moderate levels of genetic diversity that were expected based on widespread ranges (haplotype diversity h = 25 and 12; nuclear diversity He = 0.60 and 0.47 for A. hilliana and A. spondylophylla, respectively). Contemporary genetic structure was congruent at the greater landscape scale, especially in terms of strong genetic differentiation among geographically disjunct populations in less elevated areas. Measures of diversity and connectivity were associated with traits of greater geographic population proximity, population density, population size, and greater individual longevity, and some evidence for range expansion in A. hilliana. Results illustrate that low stature is associated with limited dispersal and greater patterns of genetic differentiation for congenerics in a common landscape and highlight the complex influence of taxon‐specific life history and ecological traits to seed and pollen dispersal. |
| first_indexed | 2024-12-10T08:33:16Z |
| format | Article |
| id | doaj.art-2853ecf2f22044e1909e0f86ca056f26 |
| institution | Directory Open Access Journal |
| issn | 2045-7758 |
| language | English |
| last_indexed | 2024-12-10T08:33:16Z |
| publishDate | 2022-07-01 |
| publisher | Wiley |
| record_format | Article |
| series | Ecology and Evolution |
| spelling | doaj.art-2853ecf2f22044e1909e0f86ca056f262022-12-22T01:56:02ZengWileyEcology and Evolution2045-77582022-07-01127n/an/a10.1002/ece3.9052Limited phylogeographic and genetic connectivity in Acacia species of low stature in an arid landscapeMelissa A. Millar0Rachel M. Binks1Sarah‐Louise Tapper2Bronwyn M. Macdonald3Shelley L. McArthur4Margaret Hankinson5David J. Coates6Stephen vanLeeuwen7Margaret Byrne8Department of Biodiversity, Conservation and Attractions Biodiversity and Conservation Science Bentley Western Australia AustraliaDepartment of Biodiversity, Conservation and Attractions Biodiversity and Conservation Science Bentley Western Australia AustraliaDepartment of Biodiversity, Conservation and Attractions Biodiversity and Conservation Science Bentley Western Australia AustraliaDepartment of Biodiversity, Conservation and Attractions Biodiversity and Conservation Science Bentley Western Australia AustraliaDepartment of Biodiversity, Conservation and Attractions Biodiversity and Conservation Science Bentley Western Australia AustraliaDepartment of Biodiversity, Conservation and Attractions Biodiversity and Conservation Science Bentley Western Australia AustraliaDepartment of Biodiversity, Conservation and Attractions Biodiversity and Conservation Science Bentley Western Australia AustraliaDepartment of Biodiversity, Conservation and Attractions Biodiversity and Conservation Science Bentley Western Australia AustraliaDepartment of Biodiversity, Conservation and Attractions Biodiversity and Conservation Science Bentley Western Australia AustraliaAbstract Widespread plant species are expected to maintain genetic diversity and gene flow via pollen and seed dispersal. Stature is a key life history trait that affects seed and potentially pollen dispersal, with limited stature associated with limited dispersal and greater genetic differentiation. We sampled Hill’s tabletop wattle (Acacia hilliana) and curry wattle (Acacia spondylophylla), two co‐distributed, widespread, Acacia shrubs of low stature, across the arid Pilbara region of north‐western Australia. Using chloroplast sequence and nuclear microsatellite data we evaluated patterns of population genetic and phylogeographic diversity and structure, demographic signals, ratios of pollen to seed dispersal, evidence for historical refugia, and association between elevation and diversity. Results showed strong phylogeographic (chloroplast, GST = 0.831 and 0.898 for A. hilliana and A. spondylophylla, respectively) and contemporary (nuclear, FST = 0.260 and 0.349 for A. hilliana and A. spondylophylla, respectively) genetic structure in both species. This indicates limited genetic connectivity via seed and pollen dispersal associated with Acacia species of small stature compared to taller tree and shrub acacias across the Pilbara bioregion. This effect of stature on genetic structure is superimposed on moderate levels of genetic diversity that were expected based on widespread ranges (haplotype diversity h = 25 and 12; nuclear diversity He = 0.60 and 0.47 for A. hilliana and A. spondylophylla, respectively). Contemporary genetic structure was congruent at the greater landscape scale, especially in terms of strong genetic differentiation among geographically disjunct populations in less elevated areas. Measures of diversity and connectivity were associated with traits of greater geographic population proximity, population density, population size, and greater individual longevity, and some evidence for range expansion in A. hilliana. Results illustrate that low stature is associated with limited dispersal and greater patterns of genetic differentiation for congenerics in a common landscape and highlight the complex influence of taxon‐specific life history and ecological traits to seed and pollen dispersal.https://doi.org/10.1002/ece3.9052Acaciaarid zonegenetic connectivitygenetic diversityPilbarastature |
| spellingShingle | Melissa A. Millar Rachel M. Binks Sarah‐Louise Tapper Bronwyn M. Macdonald Shelley L. McArthur Margaret Hankinson David J. Coates Stephen vanLeeuwen Margaret Byrne Limited phylogeographic and genetic connectivity in Acacia species of low stature in an arid landscape Ecology and Evolution Acacia arid zone genetic connectivity genetic diversity Pilbara stature |
| title | Limited phylogeographic and genetic connectivity in Acacia species of low stature in an arid landscape |
| title_full | Limited phylogeographic and genetic connectivity in Acacia species of low stature in an arid landscape |
| title_fullStr | Limited phylogeographic and genetic connectivity in Acacia species of low stature in an arid landscape |
| title_full_unstemmed | Limited phylogeographic and genetic connectivity in Acacia species of low stature in an arid landscape |
| title_short | Limited phylogeographic and genetic connectivity in Acacia species of low stature in an arid landscape |
| title_sort | limited phylogeographic and genetic connectivity in acacia species of low stature in an arid landscape |
| topic | Acacia arid zone genetic connectivity genetic diversity Pilbara stature |
| url | https://doi.org/10.1002/ece3.9052 |
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