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Barbot E, Dufaÿ M, Tonnabel J, Godé C, De Cauwer I. On the function of flower number: disentangling fertility from pollinator-mediated selection. Proc Biol Sci 2022; 289:20221987. [PMID: 36448279 PMCID: PMC9709571 DOI: 10.1098/rspb.2022.1987] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 11/03/2022] [Indexed: 12/03/2022] Open
Abstract
In animal-pollinated angiosperms, the 'male-function' hypothesis claims that male reproductive success (RS) should benefit from large floral displays, through pollinator attraction, while female RS is expected to be mainly limited by resource availability. As appealing as this theory might be, studies comparing selection strength on flower number in both sexes rarely document the expected asymmetry. This discrepancy could arise because flower number impacts both pollinator attraction and overall gamete number. In this study, we artificially manipulate floral displays to disentangle the fertility versus pollinator attraction components of selection, both in terms of mating and RS. In females, flower number was under strong fertility selection, as predicted in the absence of pollen limitation. By contrast, in males, flower number was mainly under sexual selection, which in turn increased male RS. However, these selection patterns were not different in males with artificially increased floral displays. This suggests that sexual selection acting on flower number in males does not occur because flower number increases pollinator attraction, but rather because more pollen is available to disperse on more mates. Our study illustrates the power of disentangling various components of selection with potentially sex-specific effects for understanding the evolution of sexual dimorphism.
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Affiliation(s)
- Estelle Barbot
- Univ. Lille, CNRS, UMR 8198 - Evo-Eco-Paleo, F-59000 Lille, France
- ISEM, Univ. Montpellier, CNRS, IRD, Montpellier, France
| | - Mathilde Dufaÿ
- CEFE, Univ. Montpellier, CNRS, Univ. Paul Valéry Montpellier 3, EPHE, IRD, Montpellier, France
| | - Jeanne Tonnabel
- ISEM, Univ. Montpellier, CNRS, IRD, Montpellier, France
- CEFE, Univ. Montpellier, CNRS, Univ. Paul Valéry Montpellier 3, EPHE, IRD, Montpellier, France
| | - Cécile Godé
- Univ. Lille, CNRS, UMR 8198 - Evo-Eco-Paleo, F-59000 Lille, France
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Naaf T, Feigs JT, Huang S, Brunet J, Cousins SAO, Decocq G, De Frenne P, Diekmann M, Govaert S, Hedwall PO, Lenoir J, Liira J, Meeussen C, Plue J, Vangansbeke P, Vanneste T, Verheyen K, Holzhauer SIJ, Kramp K. Context matters: the landscape matrix determines the population genetic structure of temperate forest herbs across Europe. LANDSCAPE ECOLOGY 2021; 37:1365-1384. [PMID: 35571363 PMCID: PMC9085688 DOI: 10.1007/s10980-021-01376-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 11/21/2021] [Indexed: 06/15/2023]
Abstract
CONTEXT Plant populations in agricultural landscapes are mostly fragmented and their functional connectivity often depends on seed and pollen dispersal by animals. However, little is known about how the interactions of seed and pollen dispersers with the agricultural matrix translate into gene flow among plant populations. OBJECTIVES We aimed to identify effects of the landscape structure on the genetic diversity within, and the genetic differentiation among, spatially isolated populations of three temperate forest herbs. We asked, whether different arable crops have different effects, and whether the orientation of linear landscape elements relative to the gene dispersal direction matters. METHODS We analysed the species' population genetic structures in seven agricultural landscapes across temperate Europe using microsatellite markers. These were modelled as a function of landscape composition and configuration, which we quantified in buffer zones around, and in rectangular landscape strips between, plant populations. RESULTS Landscape effects were diverse and often contrasting between species, reflecting their association with different pollen- or seed dispersal vectors. Differentiating crop types rather than lumping them together yielded higher proportions of explained variation. Some linear landscape elements had both a channelling and hampering effect on gene flow, depending on their orientation. CONCLUSIONS Landscape structure is a more important determinant of the species' population genetic structure than habitat loss and fragmentation per se. Landscape planning with the aim to enhance the functional connectivity among spatially isolated plant populations should consider that even species of the same ecological guild might show distinct responses to the landscape structure. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s10980-021-01376-7.
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Affiliation(s)
- Tobias Naaf
- Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalder Strasse 84, 15374 Müncheberg, Germany
| | - Jannis Till Feigs
- Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalder Strasse 84, 15374 Müncheberg, Germany
| | - Siyu Huang
- Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalder Strasse 84, 15374 Müncheberg, Germany
| | - Jörg Brunet
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Box 190, 234 22 Lomma, Sweden
| | - Sara A. O. Cousins
- Landscapes, Environment and Geomatics, Department of Physical Geography, Stockholm University, 10691 Stockholm, Sweden
| | - Guillaume Decocq
- Ecologie et Dynamique des Systèmes Anthropisés (EDYSAN, UMR 7058 CNRS), Université de Picardie Jules Verne, 1 Rue des Louvels, 80037 Amiens, France
| | - Pieter De Frenne
- Forest and Nature Lab, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Geraardsbergsesteenweg 267, 9090 Gontrode-Melle, Belgium
| | - Martin Diekmann
- Vegetation Ecology and Conservation Biology, Institute of Ecology, FB2, University of Bremen, Leobener Str., 28359 Bremen, Germany
| | - Sanne Govaert
- Forest and Nature Lab, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Geraardsbergsesteenweg 267, 9090 Gontrode-Melle, Belgium
| | - Per-Ola Hedwall
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Box 190, 234 22 Lomma, Sweden
| | - Jonathan Lenoir
- Ecologie et Dynamique des Systèmes Anthropisés (EDYSAN, UMR 7058 CNRS), Université de Picardie Jules Verne, 1 Rue des Louvels, 80037 Amiens, France
| | - Jaan Liira
- Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, 51005 Tartu, Estonia
| | - Camille Meeussen
- Forest and Nature Lab, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Geraardsbergsesteenweg 267, 9090 Gontrode-Melle, Belgium
| | - Jan Plue
- IVL Swedish Environmental Institute, Valhallavägen 81, 10031 Stockholm, Sweden
| | - Pieter Vangansbeke
- Forest and Nature Lab, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Geraardsbergsesteenweg 267, 9090 Gontrode-Melle, Belgium
| | - Thomas Vanneste
- Forest and Nature Lab, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Geraardsbergsesteenweg 267, 9090 Gontrode-Melle, Belgium
| | - Kris Verheyen
- Forest and Nature Lab, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Geraardsbergsesteenweg 267, 9090 Gontrode-Melle, Belgium
| | - Stephanie I. J. Holzhauer
- Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalder Strasse 84, 15374 Müncheberg, Germany
| | - Katja Kramp
- Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalder Strasse 84, 15374 Müncheberg, Germany
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Zhang AQ, Xiong YZ, Huang SQ. Maintenance of self-incompatibility in peripheral populations of a circumboreal woodland subshrub. AOB PLANTS 2014; 6:plu063. [PMID: 25336338 PMCID: PMC4243073 DOI: 10.1093/aobpla/plu063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 10/09/2014] [Indexed: 05/24/2023]
Abstract
Compared with self-incompatible (SI) species, species that shift to self-compatibility (SC) are more likely to colonize a new habitat. Self-incompatibility and fruit-set failure have been widely reported in European populations of Linnaea borealis (twinflower), whereas at the eastern margin of its North American distribution it showed potential SC. We investigated the breeding system of L. borealis in northwestern China, the eastern margin of the species' distribution in Eurasia. Pollinators, breeding system and pollen limitation were examined in a nature reserve with thousands of L. borealis individuals. To investigate whether fruit set was limited by mating opportunity, we compared fruit set in high-, medium- and low-density patches of L. borealis. To examine whether clonal reproduction resulted in higher fruit-set failure, we compared fruit set among different sizes of clonal ramets. Flies contributed most pollinator visits in the studied population. It was strictly SI and natural fruit set depended on insect visits. Patch density comparisons showed that L. borealis was not pollen limited in low-density patches that had significantly fewer flowers. However, it produced significantly fewer fruits per flower when clonal ramet size increased, suggesting that the high failure of fruit set in larger clones with more flowers may be caused by geitonogamy. Generalist pollinators and clonal reproduction may help L. borealis to colonize in marginal areas without the transition of the breeding system from SI to SC, but experiencing fruit-set failure resulting from geitonogamy within clones.
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Affiliation(s)
- Ai-Qin Zhang
- College of Life Science and Technology, Xinjiang University, Urumqi 830046, China
| | - Ying-Ze Xiong
- School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Shuang-Quan Huang
- School of Life Sciences, Central China Normal University, Wuhan 430079, China
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Effects of Population Size, Forest Fragmentation, and Urbanization on Seed Production and Gene Flow in an Endangered Maple (Acer miyabei). AMERICAN MIDLAND NATURALIST 2014. [DOI: 10.1674/0003-0031-172.2.303] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Talavera S, Arista M, Salgueiro FJ. Population Size, Pollination and Breeding System ofSilene stockeniiChater (Caryophyllaceae), an Annual Gynodioecious Species of Southern Spain. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/j.1438-8677.1996.tb00581.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Meindl GA, Bain DJ, Ashman TL. Edaphic factors and plant-insect interactions: direct and indirect effects of serpentine soil on florivores and pollinators. Oecologia 2013; 173:1355-66. [PMID: 23839263 DOI: 10.1007/s00442-013-2711-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 06/06/2013] [Indexed: 11/29/2022]
Abstract
Edaphic factors can lead to differences in plant morphology and tissue chemistry. However, whether these differences result in altered plant-insect interactions for soil-generalist plants is less understood. We present evidence that soil chemistry can alter plant-insect interactions both directly, through chemical composition of plant tissue, and indirectly, through plant morphology, for serpentine-tolerant Mimulus guttatus (Phrymaceae). First, we scored floral display (corolla width, number of open flowers per inflorescence, and inflorescence height), flower chemistry, pollinator visitation and florivory of M. guttatus growing on natural serpentine and non-serpentine soil over 2 years. Second, we conducted a common garden reciprocal soil transplant experiment to isolate the effect of serpentine soil on floral display traits and flower chemistry. And last, we observed arrays of field-collected inflorescences and potted plants to determine the effect of soil environment in the field on pollinator visitation and florivore damage, respectively. For both natural and experimental plants, serpentine soil caused reductions in floral display and directly altered flower tissue chemistry. Plants in natural serpentine populations received fewer pollinator visits and less damage by florivores relative to non-serpentine plants. In experimental arrays, soil environment did not influence pollinator visitation (though larger flowers were visited more frequently), but did alter florivore damage, with serpentine-grown plants receiving less damage. Our results demonstrate that the soil environment can directly and indirectly affect plant-mutualist and plant-antagonist interactions of serpentine-tolerant plants by altering flower chemistry and floral display.
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Affiliation(s)
- George A Meindl
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA,
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García-Robledo C. Restoration of Plant-Pollinator Interactions: Pollination Neighborhood and Asymmetric Pollen Flow Between Restored Habitats in a Beetle-Pollinated Aroid. Restor Ecol 2010. [DOI: 10.1111/j.1526-100x.2010.00677.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Scobie AR, Wilcock CC. Limited mate availability decreases reproductive success of fragmented populations of Linnaea borealis, a rare, clonal self-incompatible plant. ANNALS OF BOTANY 2009; 103:835-46. [PMID: 19181748 PMCID: PMC2707897 DOI: 10.1093/aob/mcp007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Revised: 09/15/2008] [Accepted: 12/04/2008] [Indexed: 05/10/2023]
Abstract
BACKGROUND AND AIMS Small populations of rare plant species are increasingly reported to have high levels of reproductive failure. The objective of this study was to understand the principal constraints on sexual reproduction in small fragmented populations of a rare clonal self-incompatible plant. METHODS The pollinator spectrum, diversity of flower colour, natural pollination and fruit-set levels of L. borealis were examined in Scotland. Artificially crossed seed production was compared within and between different flower colour types and patches. KEY RESULTS Linnaea borealis was pollinated by a diverse spectrum of insect species and the principal pollinators were muscid, syrphid and empid flies which mostly moved only small distances (<0.25 m) between flowers when foraging. Natural pollination levels were high, indicating high pollinator effectiveness, but fruit set was very low in most patches. Flower colour diversity was low in most patches and only those with a diversity of flower colour types had high fruiting success. Pollination experiments showed L. borealis to be highly self-incompatible and artificial crosses within and between patches and flower colour types confirmed that low fruit success was the result of a lack of compatible mates and limited pollen movement between them. Evidence of isolation from pollen exchange was apparent at as little as 6 m and severe at 30 m and beyond. CONCLUSIONS Limited mate availability and isolation from pollen exchange compromise the reproductive success of fragmented populations of L. borealis in Scotland. A diversity of compatible mates situated within close proximity (<6 m) is the key requirement to ensure high natural fruiting success. This study emphasizes that an understanding of the breeding system, pollinator spectrum and potential for interconnectivity via pollinator movement are fundamental to identify isolation distances and to establish when conservation intervention is necessary for rare species.
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Affiliation(s)
| | - C. C. Wilcock
- School of Biological Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, Scotland, UK
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O'Brien EK, Krauss SL. Testing the Home-Site Advantage in Forest Trees on Disturbed and Undisturbed Sites. Restor Ecol 2008. [DOI: 10.1111/j.1526-100x.2008.00453.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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WAELTI MO, MUHLEMANN JK, WIDMER A, SCHIESTL FP. Floral odour and reproductive isolation in two species ofSilene. J Evol Biol 2007; 21:111-121. [DOI: 10.1111/j.1420-9101.2007.01461.x] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Van Rossum F, Triest L. Fine-scale spatial genetic structure of the distylous Primula veris in fragmented habitats. PLANT BIOLOGY (STUTTGART, GERMANY) 2007; 9:374-82. [PMID: 17099846 DOI: 10.1055/s-2006-924632] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
In Flanders (northern Belgium), the distylous self-incompatible perennial herb Primula veris is common, but mainly occurs in fragmented habitats. Distyly, which favours disassortative mating, is characterized in P. veris by two genetically determined floral morph types (pin or thrum). Using 18 polymorphic loci, we investigated fine-scale spatial genetic structure (SGS) and spatial distribution of the morphs within four populations from two regions that differ in degree of habitat fragmentation. We studied the contributions made by sexual reproduction and clonal propagation and compared the SGS patterns between pin and thrum morph types. Clonal growth was very restricted to a few individuals and to short distances. One population showed a non-random spatial distribution of the morphs. Pin and thrum individuals differed in SGS patterns at a small scale, suggesting intrapin biparental inbreeding, also related to high plant densities. This may be explained by partial self-compatibility of the pin morph combined with restricted seed dispersal and pollinator behaviour. There is an indication of more pronounced SGS when populations occur in highly fragmented habitats. From our findings, we may hypothesize disruption of the gene flow processes if these large populations evolve into patchworks of small remnants, but also a possible risk for long-term population survival if higher intrapin biparental inbreeding leads to inbreeding depression. Our study emphasizes the need for investigating the interactions between the heterostylous breeding system, population demographic and genetic structure for understanding population dynamics in fragmented habitats and for developing sustainable conservation strategies.
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Affiliation(s)
- F Van Rossum
- Plant Science and Nature Management, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
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Nyberg Berglund AB, Saura A, Westerbergh A. Electrophoretic evidence for disomic inheritance and allopolyploid origin of the octoploid Cerastium alpinum (Caryophyllaceae). J Hered 2006; 97:296-302. [PMID: 16614135 DOI: 10.1093/jhered/esj029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The mode of inheritance of six enzyme markers in the octoploid alpine plant Cerastium alpinum was analyzed. Offspring from crosses between heterozygotes showed fixed heterozygosity at malate dehydrogenase-2, phosphoglucoisomerase-2, triosephosphate isomerase-2, and triosephosphate isomerase-3. Phosphoglucomutase-1 also showed fixed heterozygosity except in offspring from one cross. Fixed heterozygosity in five enzyme systems suggests that C. alpinum has originated through at least some allopolyploidization. Offspring from plants heterozygous for two alleles at the menadione reductase-1 (Mr-1) locus did not deviate significantly from a 1:2:1 ratio. The large proportion of homozygotes suggests disomic inheritance because any kind of polysomic inheritance would result in a substantially increased proportion of heterozygotes relative to disomic inheritance. Assuming a diploid model for Mr-1, this locus was used to analyze the population genetic structure within C. alpinum populations. Inbreeding was found in many alpine populations. This may help explain the large genetic distances found among alpine populations in a previous study. The analysis is only based on one segregating locus, and the results should therefore be treated with caution. However, by establishing the mode of inheritance through crosses, we have been able to use a codominant marker in population genetic analysis of an octoploid plant.
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Buide ML. Pollination ecology of Silene acutifolia (Caryophyllaceae): floral traits variation and pollinator attraction. ANNALS OF BOTANY 2006; 97:289-97. [PMID: 16344265 PMCID: PMC2803363 DOI: 10.1093/aob/mcj032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
BACKGROUND AND AIMS The floral display influences the composition of pollinators interacting with a plant species. Geographic and temporal variation in pollinator composition complicates the understanding of the evolutionary consequences of floral display variation. This paper analyses the relationships between Silene acutifolia, a hermaphroditic perennial herb, and its pollinators, based on field studies in the north-west of Spain. METHODS Studies were conducted over three years (1997-1999). Firstly, the main pollinators of this species were determined for two years in one population. Secondly, pollen limitation in fruit and seed production was analysed by supplementary hand pollinations, and counting the pollen grains and tubes growing in styles for two different-sized populations. Finally, the effect of flower size and number on the rate of visitation and total seed number was examined for 15 marked plants. RESULTS AND CONCLUSIONS The primary pollinators were long-tongued insects, including Hymenoptera, Lepidoptera and Diptera, but the composition and visitation frequencies differed between years. Pollen limitation occurred in one of the years of study. There was between-population variation in the number of pollen grains and pollen tubes found in styles, suggesting pollen limitation in one population. Overall, pollinators visited plants with more open flowers more frequently, and pollinated more flowers within these plants. Conversely, petal and calyx sizes had no effect on insect visitation. Plants with higher rates of visits produced higher number of seeds, suggesting that pollinator-mediated limitation of seed and fruit production may be important in some years.
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Affiliation(s)
- María Luisa Buide
- Area de Botánica, Dpto. Ciencias Ambientales, Universidad Pablo de Olavide, Sevilla 41013, Spain.
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Heiser DA, Shaw RG. THE FITNESS EFFECTS OF OUTCROSSING IN CALYLOPHUS SERRULATUS, A PERMANENT TRANSLOCATION HETEROZYGOTE. Evolution 2006. [DOI: 10.1554/05-302.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Heiser DA, Shaw RG. THE FITNESS EFFECTS OF OUTCROSSING IN CALYLOPHUS SERRULATUS, A PERMANENT TRANSLOCATION HETEROZYGOTE. Evolution 2006. [DOI: 10.1111/j.0014-3820.2006.tb01082.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Austin JD, Lougheed SC, Boag PT. Controlling for the effects of history and nonequilibrium conditions in gene flow estimates in northern bullfrog (Rana catesbeiana) populations. Genetics 2005; 168:1491-506. [PMID: 15579701 PMCID: PMC1448790 DOI: 10.1534/genetics.104.027987] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nonequilibrium conditions due to either allopatry followed by secondary contact or recent range expansion can confound measurements of gene flow among populations in previously glaciated regions. We determined the scale at which gene flow can be estimated among breeding aggregations of bullfrogs (Rana catesbeiana) at the northern limit of their range in Ontario, Canada, using seven highly polymorphic DNA microsatellite loci. We first identified breeding aggregations that likely share a common history, determined from the pattern of allelic richness, factorial correspondence analysis, and a previously published mtDNA phylogeography, and then tested for regional equilibrium by evaluating the association between pairwise F(ST) and geographic distance. Regional breeding aggregations in eastern Ontario separated by <100 km were determined to be at or near equilibrium. High levels of gene flow were measured using traditional F-statistics and likelihood estimates of Nm. Similarly high levels of recent migration (past one to three generations) were estimated among the breeding aggregations using nonequilibrium methods. We also show that, in many cases, breeding aggregations separated by up to tens of kilometers are not genetically distinct enough to be considered separate genetic populations. These results have important implications both for the identification of independent "populations" and in assessing the effect of scale in detecting patterns of genetic equilibrium and gene flow.
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Affiliation(s)
- James D Austin
- Department of Biology, Queen's University, Kingston, Ontario, Canada, K7L 3N6
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Van Rossum F, Bonnin I, Fenart S, Pauwels M, Petit D, Saumitou-Laprade P. Spatial genetic structure within a metallicolous population of Arabidopsis halleri, a clonal, self-incompatible and heavy-metal-tolerant species. Mol Ecol 2004; 13:2959-67. [PMID: 15367112 DOI: 10.1111/j.1365-294x.2004.02314.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Arabidopsis halleri, a close wild relative of A. thaliana, is a clonal, insect-pollinated herb tolerant to heavy metals (Zn, Pd, Cd) and a hyperaccumulator of Zn and Cd. It is of particular interest in the study of evolutionary processes and phytoremediation. However, little is known about its population gene flow patterns and the structure of its genetic diversity. We used five microsatellite loci to investigate the genetic structure at a fine spatial scale (10 cm to 500 m) in a metallicolous population of A. halleri. We also studied the contributions made by clonal propagation and sexual reproduction (seed and pollen dispersal) to the genetic patterns. Clonal diversity was high (D(G) > 0.9). Clonal spread occurs only at short distances (< 1 m). Both clonal spread and limited dispersal, associated with sexual reproduction, contribute to the significant spatial genetic structure revealed by spatial autocorrelation analysis. The shape of the autocorrelogram suggests that seed dispersal is restricted and pollen flow extensive, which may be related to intense activity by insect pollinators. Clonal spread was more extensive in the lowly polluted zone than in the highly polluted zone. This cannot be interpreted as a strategy for promoting the propagation of adapted genotypes under the harshest ecological constraints (highest heavy metal concentrations). The higher fine-scale spatial genetic structure found in the lowly polluted zone can be ascribed to plant densities that were lower than in the highly polluted zone. No evidence of genetic divergence due to spatial heavy metal heterogeneity was found between lowly and highly polluted zones.
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Affiliation(s)
- Fabienne Van Rossum
- Laboratoire de Génétique et Evolution des Populations Végétales, UMR CNRS 8016, FR CNRS 1818, Université de Lille 1, Bâtiment SN2, F-59655 Villeneuve d'Ascq Cedex, France
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Jürgens A. Flower scent composition in diurnal Silene species (Caryophyllaceae): phylogenetic constraints or adaption to flower visitors? BIOCHEM SYST ECOL 2004. [DOI: 10.1016/j.bse.2004.03.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Westerbergh A. An interaction between a specialized seed predator moth and its dioecious host plant shifting from parasitism to mutualism. OIKOS 2004. [DOI: 10.1111/j.0030-1299.2004.12820.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Pettersson TM, Lefkovitch LP, Giles BE. The Effect of the Sterilising Anther-Smut Fungus Microbotryum Violaceum on the Genetic Composition of Silene Dioica Populations. Hereditas 2004. [DOI: 10.1111/j.1601-5223.1999.t01-1-00177.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Berglund AB, Westerbergh A. Two postglacial immigration lineages of the polyploid Cerastium alpinum (Caryophyllaceae). Hereditas 2002; 134:171-83. [PMID: 11732854 DOI: 10.1111/j.1601-5223.2001.00171.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
The plant cover of Fennoscandia is young because of the recent glaciation. This study covers the early stages of diversification and the genetic consequences of postglacial migration of a hermaphroditic polyploid plant. Cerastium alpinum. It has a continuous distribution in the alpine region, where it grows on alpine heaths and serpentine soils that are rich in heavy metals. Within the boreal forest C. alpinum has a scattered distribution on serpentine, dolomite and steep slopes. Plants from 31 populations in Norway, Sweden and Finland were subjected to enzyme electrophoresis. Analyses of the enzyme phenotypes suggest that C. alpinum has colonized Fennoscandia through two postglacial immigration events resulting in a southeastern and a southwestern lineage. These two lineages seem to meet in a hybrid zone in northern Sweden. Large genetic differences were found among most populations in both the southeastern and the southwestern lineages. This suggests that the populations are effectively isolated from each other.
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Affiliation(s)
- A B Berglund
- Department of Natural and Environmental Sciences, Mid Sweden University, Härnösand.
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Affiliation(s)
- T H Ricketts
- Department of Biological Sciences, Stanford University, Stanford, California 94305-5020, USA.
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Colas B, Olivieri I, Riba M. Centaurea corymbosa, a cliff-dwelling species tottering on the brink of extinction: a demographic and genetic study. Proc Natl Acad Sci U S A 1997; 94:3471-6. [PMID: 9096418 PMCID: PMC20394 DOI: 10.1073/pnas.94.7.3471] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Centaurea corymbosa (Asteraceae) is endemic to a small area (< or = 3 km2), and < 500 individuals reproduce in any given year. Nevertheless, enzyme polymorphism was found within and among the six local extant populations, the most distant at 2.3 km. Levels of gene flow among populations and seed and pollen dispersal data indicated very low dispersal capacity. Rarity of long distance dispersal events coupled with traits such as prolonged juvenile period, monocarpy, and self-incompatibility precludes the establishment of new populations and thus the evolution toward colonization ability through increased dispersal rate, polycarpy, or self-compatibility. The species thus appears to be trapped on an evolutionary dead-end toward extinction, even though, from a preliminary introduction experiment, we conclude that several nearby unoccupied sites would be suitable for the species.
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Affiliation(s)
- B Colas
- Conservatoire Botanique National de Porquerolles, Castel Sainte Claire, Hyères, France
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