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Grünig S, Patsiou T, Parisod C. Ice age-driven range shifts of diploids and expanding autotetraploids of Biscutella laevigata within a conserved niche. THE NEW PHYTOLOGIST 2024; 244:1616-1628. [PMID: 39253771 DOI: 10.1111/nph.20103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Accepted: 08/21/2024] [Indexed: 09/11/2024]
Abstract
Early studies of the textbook mixed-ploidy system Biscutella laevigata highlighted diploids restricted to never-glaciated lowlands and tetraploids at high elevations across the European Alps, promoting the hypothesis that whole-genome duplication (WGD) is advantageous under environmental changes. Here we addressed long-held hypotheses on the role of hybridisation at the origin of the tetraploids, their single vs multiple origins, and whether a shift in climatic niche accompanied WGD. Climatic niche modelling together with spatial genetics and coalescent modelling based on ddRAD-seq genotyping of 17 diploid and 19 tetraploid populations was used to revisit the evolution of this species complex in space and time. Diploids differentiated into four genetic lineages corresponding to allopatric glacial refugia at the onset of the last ice age, whereas tetraploids displaying tetrasomic inheritance formed a uniform group that originated from southern diploids before the last glacial maximum. Derived from diploids occurring at high elevation, autotetraploids likely inherited their adaptation to high elevation rather than having evolved it through or after WGD. They further presented considerable postglacial expansion across the Alps and underwent admixture with diploids. Although the underpinnings of the successful expansion of autotetraploids remain elusive, differentiation in B. laevigata was chiefly driven by the glacial history of the Alps.
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Affiliation(s)
- Sandra Grünig
- Department of Biology, University of Fribourg, 1700, Fribourg, Switzerland
- Institute of Plant Sciences, University of Bern, 3013, Bern, Switzerland
| | - Theofania Patsiou
- Institute of Plant Sciences, University of Bern, 3013, Bern, Switzerland
| | - Christian Parisod
- Department of Biology, University of Fribourg, 1700, Fribourg, Switzerland
- Institute of Plant Sciences, University of Bern, 3013, Bern, Switzerland
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2
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Balogh CM, Barrett SCH. An experimental field study of inbreeding depression in an outcrossing invasive plant. FRONTIERS IN PLANT SCIENCE 2024; 15:1393294. [PMID: 39267999 PMCID: PMC11390429 DOI: 10.3389/fpls.2024.1393294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 08/09/2024] [Indexed: 09/15/2024]
Abstract
Inbreeding depression is likely to play an important role during biological invasion. But relatively few studies have investigated the fitness of selfed and outcrossed offspring in self-incompatible invasive plants in natural environments in their introduced range. Moreover, the majority of studies on inbreeding depression have investigated self-compatible species with mixed mating, and less is known about the intensity of inbreeding depression in outcrossing self-incompatible species. Here, we address these questions experimentally by comparing selfed and outcrossed progeny of purple loosestrife (Lythrum salicaria) over four growing seasons, including three under field conditions in a freshwater marsh in southern Ontario, Canada, a region where L. salicaria is highly invasive. The tristylous mating system of L. salicaria involves disassortative mating among floral morphs enforced by trimorphic incompatibility. However, owing to partial incompatibility, self-fertilized seed can be obtained by manual self-pollination thus facilitating comparisons of selfed and outcrossed progeny. We compared progeny with and without intraspecific competition from selfed or outcrossed neighbours and examined the influence of breeding treatment and competition on fitness correlates by measuring a range of life-history traits including: proportion of seeds germinating, days to germination, survival, proportion of plants flowering, time to flowering, vegetative mass, and inflorescence number and mass. We analysed data for each trait using functions from time series estimates of growth and two multiplicative estimates of fitness. We detected varying intensities of inbreeding depression for several traits in three of the four years of the experiment, including inflorescence mass and reproductive output. Cumulative inbreeding depression over four years averaged δ = 0.48 and 0.68, depending on the method used to estimate multiplicative fitness. The competition treatments did not significantly affect plant performance and the magnitude of inbreeding depression. Given the primarily outcrossing mating system of L. salicaria populations, the detection of inbreeding depression for several key life-history traits was as predicted by theory. Our results suggests that biparental inbreeding and low selfing in colonizing populations may have significant effects on demographic parameters such as population growth.
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Affiliation(s)
- Christopher M Balogh
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - Spencer C H Barrett
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
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3
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Makowski H, Lamb K, Galloway LF. Support for Baker's law: Facultative self-fertilization ability decreases pollen limitation in experimental colonization. AMERICAN JOURNAL OF BOTANY 2024; 111:e16351. [PMID: 38812263 DOI: 10.1002/ajb2.16351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 05/31/2024]
Abstract
PREMISE The ability to self-fertilize is predicted to provide an advantage in colonization because a single individual can reproduce and establish a next generation in a new location regardless of the density of mates. While there is theoretical and correlative support for this idea, the strength of mate limitation as a selective agent has not yet been delineated from other factors that can also select for self-fertilization in colonization of new habitats. We used known mating-system variation in the American bellflower (Campanula americana) to explore how plants' ability to self-fertilize can mitigate density-dependent reproduction and impact colonization success. METHODS We created experimental populations of single individuals or a small number of plants to emulate isolated colonization events. These populations were composed of plants that differed in their ability to self-fertilize. We compared pollen limitation of the single individuals to that of small populations. RESULTS Experimental populations of plants that readily self-fertilize produced consistent seed numbers regardless of population size, whereas plants with lower ability to self-fertilize had density-dependent reproduction with greater seed production in small populations than in populations composed of a single individual. CONCLUSIONS We experimentally isolated the effect of mate limitation in colonization and found that it can select for increased self-fertilization. We show the benefit of self-fertilization in colonization, which helps to explain geographic patterns of self-fertilization and shows support for Baker's law, a long-held hypothesis in the field of mating-system evolution.
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Affiliation(s)
- Hanna Makowski
- Department of Biology, University of Virginia, PO Box 400328, Charlottesville, 22904, Virginia, USA
- Black Rock Forest, 65 Reservoir Road, Cornwall, New York, 12518, USA
| | - Keric Lamb
- Department of Biology, University of Virginia, PO Box 400328, Charlottesville, 22904, Virginia, USA
| | - Laura F Galloway
- Department of Biology, University of Virginia, PO Box 400328, Charlottesville, 22904, Virginia, USA
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4
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Christenhusz MJM, Pannell JR, Twyford AD. The genome sequence of the Annual Mercury, Mercurialis annua L., 1753 (Euphorbiaceae). Wellcome Open Res 2024; 9:102. [PMID: 38854694 PMCID: PMC11157195 DOI: 10.12688/wellcomeopenres.21004.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/02/2024] [Indexed: 06/11/2024] Open
Abstract
We present a genome assembly from a diploid female Mercurialis annua (the Annual Mercury; Tracheophyta; Magnoliopsida; Malpighiales; Euphorbiaceae). The genome sequence is 453.2 megabases in span. Most of the assembly is scaffolded into 8 chromosomal pseudomolecules, including the X chromosome. The organelle genomes have also been assembled, and the mitochondrial genome is 435.28 kilobases in length, while the plastid genome is 169.65 kilobases in length.
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Affiliation(s)
| | - John R. Pannell
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Alex D. Twyford
- The University of Edinburgh, Edinburgh, Scotland, UK
- Royal Botanic Garden Edinburgh, Edinburgh, Scotland, UK
| | - Royal Botanic Gardens Kew Genome Acquisition Lab
- Royal Botanic Gardens Kew, Richmond, England, UK
- Curtin University, Perth, Western Australia, Australia
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- The University of Edinburgh, Edinburgh, Scotland, UK
- Royal Botanic Garden Edinburgh, Edinburgh, Scotland, UK
| | - Plant Genome Sizing collective
- Royal Botanic Gardens Kew, Richmond, England, UK
- Curtin University, Perth, Western Australia, Australia
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- The University of Edinburgh, Edinburgh, Scotland, UK
- Royal Botanic Garden Edinburgh, Edinburgh, Scotland, UK
| | - Darwin Tree of Life Barcoding collective
- Royal Botanic Gardens Kew, Richmond, England, UK
- Curtin University, Perth, Western Australia, Australia
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- The University of Edinburgh, Edinburgh, Scotland, UK
- Royal Botanic Garden Edinburgh, Edinburgh, Scotland, UK
| | - Wellcome Sanger Institute Tree of Life programme
- Royal Botanic Gardens Kew, Richmond, England, UK
- Curtin University, Perth, Western Australia, Australia
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- The University of Edinburgh, Edinburgh, Scotland, UK
- Royal Botanic Garden Edinburgh, Edinburgh, Scotland, UK
| | - Wellcome Sanger Institute Scientific Operations: DNA Pipelines collective
- Royal Botanic Gardens Kew, Richmond, England, UK
- Curtin University, Perth, Western Australia, Australia
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- The University of Edinburgh, Edinburgh, Scotland, UK
- Royal Botanic Garden Edinburgh, Edinburgh, Scotland, UK
| | - Tree of Life Core Informatics collective
- Royal Botanic Gardens Kew, Richmond, England, UK
- Curtin University, Perth, Western Australia, Australia
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- The University of Edinburgh, Edinburgh, Scotland, UK
- Royal Botanic Garden Edinburgh, Edinburgh, Scotland, UK
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5
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Kim AS, Kreiner JM, Hernández F, Bock DG, Hodgins KA, Rieseberg LH. Temporal collections to study invasion biology. Mol Ecol 2023; 32:6729-6742. [PMID: 37873879 DOI: 10.1111/mec.17176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/07/2023] [Accepted: 10/11/2023] [Indexed: 10/25/2023]
Abstract
Biological invasions represent an extraordinary opportunity to study evolution. This is because accidental or deliberate species introductions have taken place for centuries across large geographical scales, frequently prompting rapid evolutionary transitions in invasive populations. Until recently, however, the utility of invasions as evolutionary experiments has been hampered by limited information on the makeup of populations that were part of earlier invasion stages. Now, developments in ancient and historical DNA technologies, as well as the quickening pace of digitization for millions of specimens that are housed in herbaria and museums globally, promise to help overcome this obstacle. In this review, we first introduce the types of temporal data that can be used to study invasions, highlighting the timescale captured by each approach and their respective limitations. We then discuss how ancient and historical specimens as well as data available from prior invasion studies can be used to answer questions on mechanisms of (mal)adaptation, rates of evolution, or community-level changes during invasions. By bridging the gap between contemporary and historical invasive populations, temporal data can help us connect pattern to process in invasion science. These data will become increasingly important if invasions are to achieve their full potential as experiments of evolution in nature.
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Affiliation(s)
- Amy S Kim
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Julia M Kreiner
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Fernando Hernández
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dan G Bock
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kathryn A Hodgins
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Loren H Rieseberg
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
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6
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Shults P, Zhang X, Moran M, Cohnstaedt LW, Gerry AC, Vargo EL, Eyer PA. Immigration and seasonal bottlenecks: high inbreeding despite high genetic diversity in an oscillating population of Culicoides sonorensis (Diptera: Ceratopogonidae). JOURNAL OF MEDICAL ENTOMOLOGY 2023; 60:987-997. [PMID: 37417303 DOI: 10.1093/jme/tjad068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 05/01/2023] [Accepted: 06/12/2023] [Indexed: 07/08/2023]
Abstract
Most population genetic studies concern spatial genetic differentiation, but far fewer aim at analyzing the temporal genetic changes that occur within populations. Vector species, including mosquitoes and biting midges, are often characterized by oscillating adult population densities, which may affect their dispersal, selection, and genetic diversity over time. Here, we used a population of Culicoides sonorensis from a single site in California to investigate short-term (intra-annual) and long-term (inter-annual) temporal variation in genetic diversity over a 3 yr period. This biting midge species is the primary vector of several viruses affecting both wildlife and livestock, thus a better understanding of the population dynamics of this species can help inform epidemiological studies. We found no significant genetic differentiation between months or years, and no correlation between adult populations and the inbreeding coefficient (FIS). However, we show that repeated periods of low adult abundance during cooler winter months resulted in recurring bottleneck events. Interestingly, we also found a high number of private and rare alleles, which suggests both a large, stable population, as well as a constant influx of migrants from nearby populations. Overall, we showed that the high number of migrants maintains a high level of genetic diversity by introducing new alleles, while this increased diversity is counterbalanced by recurrent bottleneck events potentially purging unfit alleles each year. These results highlight the temporal influences on population structure and genetic diversity in C. sonorensis and provide insight into factors effecting genetic variation that may occur in other vector species with fluctuating populations.
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Affiliation(s)
- Phillip Shults
- USDA-ARS, Foreign Arthropod-Borne Animal Diseases Research Unit (FABADRU), 1515 College Avenue, Manhattan, KS 66502, USA
| | - Xinmi Zhang
- Department of Entomology, University of California Riverside, Riverside, CA 92521, USA
| | - Megan Moran
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA
| | - Lee W Cohnstaedt
- USDA-ARS, Foreign Arthropod-Borne Animal Diseases Research Unit (FABADRU), 1515 College Avenue, Manhattan, KS 66502, USA
| | - Alec C Gerry
- Department of Entomology, University of California Riverside, Riverside, CA 92521, USA
| | - Edward L Vargo
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA
| | - Pierre-Andre Eyer
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA
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7
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Zeitler L, Parisod C, Gilbert KJ. Purging due to self-fertilization does not prevent accumulation of expansion load. PLoS Genet 2023; 19:e1010883. [PMID: 37656747 PMCID: PMC10501686 DOI: 10.1371/journal.pgen.1010883] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 09/14/2023] [Accepted: 07/25/2023] [Indexed: 09/03/2023] Open
Abstract
As species expand their geographic ranges, colonizing populations face novel ecological conditions, such as new environments and limited mates, and suffer from evolutionary consequences of demographic change through bottlenecks and mutation load accumulation. Self-fertilization is often observed at species range edges and, in addition to countering the lack of mates, is hypothesized as an evolutionary advantage against load accumulation through increased homozygosity and purging. We study how selfing impacts the accumulation of genetic load during range expansion via purging and/or speed of colonization. Using simulations, we disentangle inbreeding effects due to demography versus due to selfing and find that selfers expand faster, but still accumulate load, regardless of mating system. The severity of variants contributing to this load, however, differs across mating system: higher selfing rates purge large-effect recessive variants leaving a burden of smaller-effect alleles. We compare these predictions to the mixed-mating plant Arabis alpina, using whole-genome sequences from refugial outcrossing populations versus expanded selfing populations. Empirical results indicate accumulation of expansion load along with evidence of purging in selfing populations, concordant with our simulations, suggesting that while purging is a benefit of selfing evolving during range expansions, it is not sufficient to prevent load accumulation due to range expansion.
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Affiliation(s)
- Leo Zeitler
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Christian Parisod
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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8
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Olsen KC, Levitan DR. Interpopulation variation in inbreeding is primarily driven by tolerance of mating with relatives in a spermcasting invertebrate. J Evol Biol 2023; 36:95-108. [PMID: 36420993 PMCID: PMC10098478 DOI: 10.1111/jeb.14125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 10/19/2022] [Accepted: 10/24/2022] [Indexed: 11/25/2022]
Abstract
The degree to which individuals inbreed is a fundamental aspect of population biology shaped by both passive and active processes. Yet, the relative influences of random and non-random mating on the overall magnitude of inbreeding are not well characterized for many taxa. We quantified variation in inbreeding among qualitatively accessible and isolated populations of a sessile marine invertebrate (the colonial ascidian Lissoclinum verrilli) in which hermaphroditic colonies cast sperm into the water column for subsequent uptake and internal fertilization. We compared estimates of inbreeding to simulations predicting random mating within sites to evaluate if levels of inbreeding were (1) less than expected because of active attempts to limit inbreeding, (2) as predicted by genetic subdivision and passive inbreeding tolerance, or (3) greater than simulations due to active attempts to promote inbreeding via self-fertilization or a preference for related mates. We found evidence of restricted gene flow and significant differences in the genetic diversity of L. verrilli colonies among sites, indicating that on average colonies were weakly related in accessible locations, but their levels of relatedness matched that of first cousins or half-siblings on isolated substrates. Irrespective of population size, progeny arrays revealed variation in the magnitude of inbreeding across sites that tracked with the mean relatedness of conspecifics. Biparental reproduction was confirmed in most offspring (86%) and estimates of total inbreeding largely overlapped with simulations of random mating, suggesting that interpopulation variation in mother-offspring resemblance was primarily due to genetic subdivision and passive tolerance of related mates. Our results highlight the influence of demographic isolation on the genetic composition of populations, and support theory predicting that tolerance of biparental inbreeding, even when mates are closely related, may be favoured under a broad set of ecological and evolutionary conditions.
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Affiliation(s)
- Kevin C Olsen
- Department of Biological Science, Florida State University, Tallahassee, Florida, USA
| | - Don R Levitan
- Department of Biological Science, Florida State University, Tallahassee, Florida, USA
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Clo J, Kolář F. Inbreeding depression in polyploid species: a meta-analysis. Biol Lett 2022; 18:20220477. [PMID: 36514955 PMCID: PMC9748776 DOI: 10.1098/rsbl.2022.0477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 11/24/2022] [Indexed: 12/15/2022] Open
Abstract
Whole-genome duplication is a common mutation in eukaryotes with far-reaching phenotypic effects, the resulting morphological and fitness consequences and how they affect the survival of polyploid lineages are intensively studied. Another important factor may also determine the probability of establishment and success of polyploid lineages: inbreeding depression. Inbreeding depression is expected to play an important role in the establishment of neopolyploid lineages, their capacity to colonize new environments, and in the simultaneous evolution of ploidy and other life-history traits such as self-fertilization. Both theoretically and empirically, there is no consensus on the consequences of polyploidy on inbreeding depression. In this meta-analysis, we investigated the effect of polyploidy on the evolution of inbreeding depression, by performing a meta-analysis within angiosperm species. The main results of our study are that the consequences of polyploidy on inbreeding depression are complex and depend on the time since polyploidization. We found that young polyploid lineages have a much lower amount of inbreeding depression than their diploid relatives and their established counterparts. Natural polyploid lineages are intermediate and have a higher amount of inbreeding depression than synthetic neopolyploids, and a smaller amount than diploids, suggesting that the negative effect of polyploidy on inbreeding depression decreases with time since polyploidization.
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Affiliation(s)
- Josselin Clo
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, CZ-128 01 Prague, Czech Republic
| | - Filip Kolář
- Institute of Botany of the Czech Academy of Sciences, Zámek 1, CZ-252 43 Průhonice, Czech Republic
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10
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Wang D, Accatino F, Smith JLD, Wang T. Contributions of distemper control and habitat expansion to the Amur leopard viability. Commun Biol 2022; 5:1153. [PMID: 36310335 PMCID: PMC9618572 DOI: 10.1038/s42003-022-04127-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 10/18/2022] [Indexed: 11/09/2022] Open
Abstract
The Amur leopard (Panthera pardus orientalis) is a critically endangered top predator that struggles on the brink of extinction due to threats such as canine distemper virus (CDV), habitat loss, and inbreeding depression. Here we develop a viability analysis metamodel that combines a traditional individual-based demographic model with an epidemiological model to assess the benefits of alternative population management actions in response to multiple distinct threats. Our results showed an extinction risk of 10.3%-99.9% if no management actions were taken over 100 years under different levels of inbreeding depression. Reducing the risk of CDV infection in Amur leopards through the low-coverage vaccination of leopards and the management of sympatric domestic dogs could effectively improve the survival probability of the leopard population, and with habitat expansion added to these management measures, the population expanded further. Our findings highlight that protecting the Amur leopard necessitates a multifaceted synergistic effort, and controlling multiple threats together may significantly escalate overall viability of a species, especially for small-isolated threatened population. More broadly, our modeling framework could offer critical perspectives and scientific support for conservation planning, as well as specific adaptive management actions for endangered species around the world. In the absence of management strategies, canine distemper virus threatens the future existence of the endangered Amur leopard.
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11
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Prior CJ, Busch JW. Selfing rate variation within species is unrelated to life-history traits or geographic range position. AMERICAN JOURNAL OF BOTANY 2021; 108:2294-2308. [PMID: 34632564 DOI: 10.1002/ajb2.1766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 08/25/2021] [Accepted: 08/27/2021] [Indexed: 06/13/2023]
Abstract
PREMISE In plants, populations and species vary widely along the continuum from outcrossing to selfing. Life-history traits and ecological circumstances influence among-species variation in selfing rates, but their general role in explaining intraspecific variation is unknown. Using a database of plant species, we test whether life-history traits, geographic range position, or abundance predict selfing rate variation among populations. METHODS We identified species where selfing rates were estimated in at least three populations at known locations. Two key life-history traits (generation time and growth form) were used to predict within-species selfing rate variation. Populations sampled within a species' native range were assessed for proximity to the nearest edge and abundance. Finally, we conducted linear and segmented regressions to determine functional relationships between selfing rate and geographic range position within species. RESULTS Selfing rates for woody species varied less than for herbs, which is explained by the lower average selfing rate of woody species. Relationships between selfing and peripherality or abundance significantly varied among species in their direction and magnitude. However, there was no general pattern of increased selfing toward range edges. A power analysis shows that tests of this hypothesis require studying many (i.e., 40+) populations. CONCLUSIONS Intraspecific variation in plant mating systems is often substantial yet remains difficult to explain. Beyond sampling more populations, future tests of biogeographic hypotheses will benefit from phylogeographic information concerning specific range edges, the study of traits influencing mating system (e.g., herkogamy), and measures of abundance at local scales (e.g., population density).
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Affiliation(s)
- Carly J Prior
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Jeremiah W Busch
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
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12
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Pannell JR. Linking key dimensions of plant phenotypic diversity. A commentary on: 'Mating systems and life history'. ANNALS OF BOTANY 2021; 127:iii-v. [PMID: 33758904 PMCID: PMC8225277 DOI: 10.1093/aob/mcab023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
This article comments on: Yue Ma, Spencer C. H. Barrett, Fang-Yuan Wang, Jun-Chen Deng and Wei-Ning Bai, Do annual and perennial populations of an insect-pollinated plant species differ in mating system?, Annals of Botany, Volume 127, Issue 7, 4 June 2021, Pages 853–864, 10.1093/aob/mcaa178
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Affiliation(s)
- John R Pannell
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
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13
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Llanos-Garrido A, Briega-Álvarez A, Pérez-Tris J, Díaz JA. Environmental association modelling with loci under divergent selection predicts the distribution range of a lizard. Mol Ecol 2021; 30:3856-3868. [PMID: 34047420 DOI: 10.1111/mec.16002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 05/05/2021] [Accepted: 05/20/2021] [Indexed: 11/28/2022]
Abstract
During the historical building of a species range, individual colonizers have to confront different ecological challenges, and the capacity of the species to broaden its range may depend on the total amount of adaptive genetic variation supplied by evolution. We set out to increase our understanding of what defines a range and the role of underlying genetics by trying to predict an entire species' range from the geographical distribution of its genetic diversity under selection. We sampled five populations of the western Mediterranean lizard Psammodromus algirus that inhabit a noticeable environmental gradient of temperature and precipitation. We correlated the genotypes of 95 individuals (18-20 individuals per population) for 21 SNPs putatively under selection with environmental scores on a bioclimatic gradient, using 1 × 1 km2 grid cells as sampling units. By extrapolating the resulting model to all possible combinations of alleles, we inferred all the geographic cells that were theoretically suitable for a given amount of genetic variance under selection. The inferred distribution range overlapped to a large extent with the realized range of the species (77.46% of overlap), including an accurate prediction of internal gaps and range borders. Our results suggest an adaptability threshold determined by the amount of genetic variation available that would be required to warrant adaptation beyond a certain limit of environmental variation. These results support the idea that the expansion of a species' range can be ultimately linked to the arising of new variants under selection (either newly selected variants from standing genetic variation or innovative mutations under selection).
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Affiliation(s)
- Alejandro Llanos-Garrido
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA.,Department of Biodiversity, Ecology and Evolution, UCM, Madrid, Spain
| | - Andrea Briega-Álvarez
- Museum für Naturkunde, Leibniz-Institut für Evolutions und Biodiversitätsforschung Berlin, Berlin, Germany
| | - Javier Pérez-Tris
- Department of Biodiversity, Ecology and Evolution, UCM, Madrid, Spain
| | - José A Díaz
- Department of Biodiversity, Ecology and Evolution, UCM, Madrid, Spain
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14
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Takou M, Hämälä T, Koch EM, Steige KA, Dittberner H, Yant L, Genete M, Sunyaev S, Castric V, Vekemans X, Savolainen O, de Meaux J. Maintenance of Adaptive Dynamics and No Detectable Load in a Range-Edge Outcrossing Plant Population. Mol Biol Evol 2021; 38:1820-1836. [PMID: 33480994 PMCID: PMC8097302 DOI: 10.1093/molbev/msaa322] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
During range expansion, edge populations are expected to face increased genetic drift, which in turn can alter and potentially compromise adaptive dynamics, preventing the removal of deleterious mutations and slowing down adaptation. Here, we contrast populations of the European subspecies Arabidopsis lyrata ssp. petraea, which expanded its Northern range after the last glaciation. We document a sharp decline in effective population size in the range-edge population and observe that nonsynonymous variants segregate at higher frequencies. We detect a 4.9% excess of derived nonsynonymous variants per individual in the range-edge population, suggesting an increase of the genomic burden of deleterious mutations. Inference of the fitness effects of mutations and modeling of allele frequencies under the explicit demographic history of each population predicts a depletion of rare deleterious variants in the range-edge population, but an enrichment for fixed ones, consistent with the bottleneck effect. However, the demographic history of the range-edge population predicts a small net decrease in per-individual fitness. Consistent with this prediction, the range-edge population is not impaired in its growth and survival measured in a common garden experiment. We further observe that the allelic diversity at the self-incompatibility locus, which ensures strict outcrossing and evolves under negative frequency-dependent selection, has remained unchanged. Genomic footprints indicative of selective sweeps are broader in the Northern population but not less frequent. We conclude that the outcrossing species A. lyrata ssp. petraea shows a strong resilience to the effect of range expansion.
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Affiliation(s)
- Margarita Takou
- Institute of Botany, University of Cologne, Cologne, Germany
| | - Tuomas Hämälä
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, USA
| | - Evan M Koch
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Kim A Steige
- Institute of Botany, University of Cologne, Cologne, Germany
| | | | - Levi Yant
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Mathieu Genete
- CNRS, UMR 8198 – Evo-Eco-Paleo, University of Lille, Lille, France
| | - Shamil Sunyaev
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Vincent Castric
- CNRS, UMR 8198 – Evo-Eco-Paleo, University of Lille, Lille, France
| | - Xavier Vekemans
- CNRS, UMR 8198 – Evo-Eco-Paleo, University of Lille, Lille, France
| | - Outi Savolainen
- Department of Ecology and Genetics, University of Oulu, Oulu, Finland
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15
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Eriksson M, Rafajlović M. The Effect of the Recombination Rate between Adaptive Loci on the Capacity of a Population to Expand Its Range. Am Nat 2021; 197:526-542. [PMID: 33908832 DOI: 10.1086/713669] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractPrevious theoretical work on range expansions over heterogeneous environments showed that there is a critical environmental gradient where range expansion stops. For populations with freely recombining loci underlying the trait under selection (hereafter, "adaptive loci"), the critical gradient in one-dimensional habitats depends on the fitness cost of dispersal and the strength of selection relative to genetic drift. Here, we extend the previous work in two directions and ask, What is the role of the recombination rate between the adaptive loci during range expansions? And what effect does the ability of selfing as opposed to obligate outcrossing have on range expansions? To answer these questions, we use computer simulations. We demonstrate that while reduced recombination rates between adaptive loci slow down range expansions as a result of poor purging of locally deleterious alleles at the expansion front, they may also allow a species to occupy a greater range. In addition, we find that the allowance of selfing may improve the ability of populations to expand their ranges, for example, because selfing among potentially rare high-fitness individuals facilitates the establishment and maintenance of locally well-adapted genotypes. We conclude that during range expansions there is a trade-off between positive and negative effects of recombination within and between individuals.
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16
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McCoy SJ, Krueger‐Hadfield SA, Mieszkowska N. Evolutionary Phycology: Toward a Macroalgal Species Conceptual Framework. JOURNAL OF PHYCOLOGY 2020; 56:1404-1413. [PMID: 32726874 PMCID: PMC7883729 DOI: 10.1111/jpy.13059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 07/16/2020] [Indexed: 06/11/2023]
Abstract
Species concepts formalize evolutionary and ecological processes, but often conflict with one another when considering the mechanisms that ultimately lead to species delimitation. Evolutionary biologists are, however, recognizing that the conceptualization of a species is separate and distinct from the delimitation of species. Indeed, if species are generally defined as separately evolving metapopulation lineages, then characteristics, such as reproductive isolation or monophyly, can be used as evidence of lineage separation and no longer conflict with the conceptualization of a species. However, little of this discussion has addressed the formalization of this evolutionary conceptual framework for macroalgal species. This may be due to the complexity and variation found in macroalgal life cycles. While macroalgal mating system variation and patterns of hybridization and introgression have been identified, complex algal life cycles generate unique eco-evolutionary consequences. Moreover, the discovery of frequent macroalgal cryptic speciation has not been accompanied by the study of the evolutionary ecology of those lineages, and, thus, an understanding of the mechanisms underlying such rampant speciation remain elusive. In this perspective, we aim to further the discussion and interest in species concepts and speciation processes in macroalgae. We propose a conceptual framework to enable phycological researchers and students alike to portray these processes in a manner consistent with dialogue at the forefront of evolutionary biology. We define a macroalgal species as an independently evolving metapopulation lineage, whereby we can test for reproductive isolation or the occupation of distinct adaptive zones, among other mechanisms, as secondary lines of supporting evidence.
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Affiliation(s)
- Sophie J. McCoy
- Department of Biological ScienceFlorida State University319 Stadium Dr.TallahasseeFlorida32312USA
| | - Stacy A. Krueger‐Hadfield
- Department of BiologyUniversity of Alabama at Birmingham1300 University BlvdBirminghamAlabama35294USA
| | - Nova Mieszkowska
- Department of Environmental SciencesUniversity of LiverpoolLiverpoolL69 3GPUK
- Marine Biological Association of the United KingdomThe LaboratoryCitadel HillPlymouthDevonPL1 2PBUK
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17
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Cossard GG, Pannell JR. Enhanced leaky sex expression in response to pollen limitation in the dioecious plant Mercurialis annua. J Evol Biol 2020; 34:416-422. [PMID: 33098734 PMCID: PMC7984330 DOI: 10.1111/jeb.13720] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/23/2020] [Accepted: 09/25/2020] [Indexed: 02/02/2023]
Abstract
In dioecious plants, males and females frequently show ‘leaky’ sex expression, with individuals occasionally producing flowers of the opposite sex. This leaky sex expression may have enabled the colonization of oceanic islands by dioecious plant species, and it is likely to represent the sort of variation upon which selection acts to bring about evolutionary transitions from dioecy to hermaphroditism. Although leakiness is commonly reported for dioecious species, it is not known whether it has plastic component. The question is interesting because males or females with an ability to enhance their leakiness plastically in the absence of mates would have an advantage of being able to produce progeny by self‐fertilization. Here, we demonstrate that leaky sex expression in the wind‐pollinated dioecious herb Mercurialis annua is plastically responsive to its mating context. We compared experimental populations of females growing either with or without males. Females growing in the absence of males were leakier in their sex expression than controls growing with males, producing more than twice as many male flowers. Our results thus provide a striking instance of plasticity in the reproductive behaviour of plants that is likely adaptive. We consider how females might sense their mating environment as a function of pollen availability, and we discuss possible constraints on the evolution of plasticity in sex expression when the environmental signals that individuals receive are unreliable.
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Affiliation(s)
- Guillaume G Cossard
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
| | - John R Pannell
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
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18
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Abdallah D, Baraket G, Perez V, Salhi Hannachi A, Hormaza JI. Self-compatibility in peach [ Prunus persica (L.) Batsch]: patterns of diversity surrounding the S-locus and analysis of SFB alleles. HORTICULTURE RESEARCH 2020; 7:170. [PMID: 33082976 PMCID: PMC7527504 DOI: 10.1038/s41438-020-00392-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/08/2020] [Accepted: 08/12/2020] [Indexed: 05/07/2023]
Abstract
Self-incompatibility (SI) to self-compatibility (SC) transition is one of the most frequent and prevalent evolutionary shifts in flowering plants. Prunus L. (Rosaceae) is a genus of over 200 species most of which exhibit a Gametophytic SI system. Peach [Prunus persica (L.) Batsch; 2n = 16] is one of the few exceptions in the genus known to be a fully self-compatible species. However, the evolutionary process of the complete and irreversible loss of SI in peach is not well understood and, in order to fill that gap, in this study 24 peach accessions were analyzed. Pollen tube growth was controlled in self-pollinated flowers to verify their self-compatible phenotypes. The linkage disequilibrium association between alleles at the S-locus and linked markers at the end of the sixth linkage group was not significant (P > 0.05), except with the closest markers suggesting the absence of a signature of negative frequency dependent selection at the S-locus. Analysis of SFB1 and SFB2 protein sequences allowed identifying the absence of some variable and hypervariable domains and the presence of additional α-helices at the C-termini. Molecular and evolutionary analysis of SFB nucleotide sequences showed a signature of purifying selection in SFB2, while the SFB1 seemed to evolve neutrally. Thus, our results show that the SFB2 allele diversified after P. persica and P. dulcis (almond) divergence, a period which is characterized by an important bottleneck, while SFB1 diversified at a transition time between the bottleneck and population expansion.
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Affiliation(s)
- Donia Abdallah
- Faculté des Sciences de Tunis, Département Biologie, Université de Tunis El Manar, 2092 Tunis, Tunisie
| | - Ghada Baraket
- Faculté des Sciences de Tunis, Département Biologie, Université de Tunis El Manar, 2092 Tunis, Tunisie
| | - Veronica Perez
- Laboratorio de Agrobiología Juan José Bravo Rodríguez (Cabildo Insular de La Palma), Unidad Técnica del Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), 38700 S/C La Palma, Canary Islands, Spain
| | - Amel Salhi Hannachi
- Faculté des Sciences de Tunis, Département Biologie, Université de Tunis El Manar, 2092 Tunis, Tunisie
| | - Jose I. Hormaza
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM La Mayora-UMA-CSIC), 29750 Algarrobo-Costa, Malaga Spain
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19
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Becheler R, Guillemin M, Stoeckel S, Mauger S, Saunier A, Brante A, Destombe C, Valero M. After a catastrophe, a little bit of sex is better than nothing: Genetic consequences of a major earthquake on asexual and sexual populations. Evol Appl 2020; 13:2086-2100. [PMID: 32908606 PMCID: PMC7463374 DOI: 10.1111/eva.12967] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 03/04/2020] [Accepted: 03/05/2020] [Indexed: 11/27/2022] Open
Abstract
Catastrophic events can have profound effects on the demography of a population and consequently on genetic diversity. The dynamics of postcatastrophic recovery and the role of sexual versus asexual reproduction in buffering the effects of massive perturbations remain poorly understood, in part because the opportunity to document genetic diversity before and after such events is rare. Six natural (purely sexual) and seven cultivated (mainly clonal due to farming practices) populations of the red alga Agarophyton chilense were surveyed along the Chilean coast before, in the days after and 2 years after the 8.8 magnitude earthquake in 2010. The genetic diversity of sexual populations appeared sensitive to this massive perturbation, notably through the loss of rare alleles immediately after the earthquake. By 2012, the levels of diversity returned to those observed before the catastrophe, probably due to migration. In contrast, enhanced rates of clonality in cultivated populations conferred a surprising ability to buffer the instantaneous loss of diversity. After the earthquake, farmers increased the already high rate of clonality to maintain the few surviving beds, but most of them collapsed rapidly. Contrasting fates between sexual and clonal populations suggest that betting on strict clonality to sustain production is risky, probably because this extreme strategy hampered adaptation to the brutal environmental perturbation induced by the catastrophe.
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Affiliation(s)
- Ronan Becheler
- Centro de Conservación MarinaDepartamento de EcologíaFacultad de Ciencias BiológicasPontificia Universidad Católica de ChileCasillaChile
- UMI 3614Evolutionary Biology and Ecology of AlgaeCNRSSorbonne UniversitéUniversidad Austral de ChilePontificia Universidad Católica de ChileRoscoffFrance
| | - Marie‐Laure Guillemin
- UMI 3614Evolutionary Biology and Ecology of AlgaeCNRSSorbonne UniversitéUniversidad Austral de ChilePontificia Universidad Católica de ChileRoscoffFrance
- Instituto de Ciencias Ambientales y EvolutivasFacultad de CienciasUniversidad Austral de ChileValdiviaChile
| | - Solenn Stoeckel
- UMR1349 Institute for Genetics, Environment and Plant ProtectionINRALe RheuFrance
| | - Stéphane Mauger
- UMI 3614Evolutionary Biology and Ecology of AlgaeCNRSSorbonne UniversitéUniversidad Austral de ChilePontificia Universidad Católica de ChileRoscoffFrance
| | - Alice Saunier
- UMI 3614Evolutionary Biology and Ecology of AlgaeCNRSSorbonne UniversitéUniversidad Austral de ChilePontificia Universidad Católica de ChileRoscoffFrance
- Instituto de Ciencias Ambientales y EvolutivasFacultad de CienciasUniversidad Austral de ChileValdiviaChile
| | - Antonio Brante
- Departamento de EcologíaFacultad de CienciasUniversidad Católica de la Santísima Concepción (UCSC)ConcepciónChile
- Centro de Investigación en Biodiversidad y Ambientes Sustentables (CIBAS)UCSCConcepciónChile
| | - Christophe Destombe
- UMI 3614Evolutionary Biology and Ecology of AlgaeCNRSSorbonne UniversitéUniversidad Austral de ChilePontificia Universidad Católica de ChileRoscoffFrance
| | - Myriam Valero
- UMI 3614Evolutionary Biology and Ecology of AlgaeCNRSSorbonne UniversitéUniversidad Austral de ChilePontificia Universidad Católica de ChileRoscoffFrance
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20
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Encinas-Viso F, Young AG, Pannell JR. The loss of self-incompatibility in a range expansion. J Evol Biol 2020; 33:1235-1244. [PMID: 32557922 DOI: 10.1111/jeb.13665] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 11/27/2022]
Abstract
It is commonly observed that plant species' range margins are enriched for increased selfing rates and, in otherwise self-incompatible species, for self-compatibility (SC). This has often been attributed to a response to selection under mate and/or pollinator limitation. However, range expansion can also cause reduced inbreeding depression, and this could facilitate the evolution of selfing in the absence of mate or pollinator limitation. Here, we explore this idea using spatially explicit individual-based simulations of a range expansion, in which inbreeding depression, variation in self-incompatibility (SI), and mate availability evolve. Under a wide range of conditions, the simulated range expansion brought about the evolution of selfing after the loss of SI in range-marginal populations. Under conditions of high recombination between the self-incompatibility locus (S-locus) and viability loci, SC remained marginal in the expanded metapopulation and could not invade the range core, which remained self-incompatible. In contrast, under low recombination and migration rates, SC was frequently able to displace SI in the range core by maintaining its association with a genomic background with purged genetic load. We conclude that the evolution of inbreeding depression during a range expansion promotes the evolution of SC at range margins, especially under high rates of recombination..
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Affiliation(s)
- Francisco Encinas-Viso
- Centre for Australian National Biodiversity Research, CSIRO National Research Collections, Canberra, ACT, Australia
| | - Andrew G Young
- Centre for Australian National Biodiversity Research, CSIRO National Research Collections, Canberra, ACT, Australia.,Centre for Biodiversity Analysis, The Australian National University, Canberra, ACT, Australia
| | - John R Pannell
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
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21
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Perrier A, Sánchez-Castro D, Willi Y. Expressed mutational load increases toward the edge of a species' geographic range. Evolution 2020; 74:1711-1723. [PMID: 32538471 DOI: 10.1111/evo.14042] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 05/26/2020] [Accepted: 06/05/2020] [Indexed: 12/14/2022]
Abstract
There is no general explanation for why species have restricted geographic distributions. One hypothesis posits that range expansion or increasing scarcity of suitable habitat results in accumulation of mutational load due to enhanced genetic drift, which constrains population performance toward range limits and further expansion. We tested this hypothesis in the North American plant, Arabidopsis lyrata. We experimentally assessed mutational load by crossing plants of 20 populations from across the entire species range and by raising the offspring of within- and between-population crosses at five common garden sites within and beyond the range. Offspring performance was tracked over three growing seasons. The heterosis effect, depicting expressed mutational load, was increased in populations with heightened genomic estimates of load, longer expansion distance or long-term isolation, and a selfing mating system. The decline in performance of within-population crosses amounted to 80%. Mutation accumulation due to past range expansion and long-term isolation of populations in the area of range margins is therefore a strong determinant of population-mean performance, and the magnitude of effect may be sufficient to cause range limits.
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Affiliation(s)
- Antoine Perrier
- Department of Environmental Sciences, University of Basel, Basel, 4056, Switzerland
| | - Darío Sánchez-Castro
- Department of Environmental Sciences, University of Basel, Basel, 4056, Switzerland
| | - Yvonne Willi
- Department of Environmental Sciences, University of Basel, Basel, 4056, Switzerland
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22
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Jiménez-López FJ, Ortiz PL, Talavera M, Pannell JR, Arista M. The role of lateral and vertical herkogamy in the divergence of the blue- and red-flowered lineages of Lysimachia arvensis. ANNALS OF BOTANY 2020; 125:1127-1135. [PMID: 32185392 PMCID: PMC7262470 DOI: 10.1093/aob/mcaa047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Accepted: 03/15/2020] [Indexed: 05/23/2023]
Abstract
BACKGROUND AND AIMS Herkogamy, or anther-stigma separation, is known to reduce self-pollen deposition, but little is known about the relative efficacy of different modes or conformations of herkogamy. We assessed the effectiveness of vertical versus lateral herkogamy in preventing or promoting self-pollen deposition in the annual herb Lysimachia arvensis, a plant with lineages that differ in flower colour, and in which flowers first display lateral and then vertical herkogamy. Because mating between the two lineages compromises fitness through the production of low-quality hybrid offspring, we tested the prediction that individuals sampled from sites occupied by both lineages should have flowers that promote autonomous self-pollen deposition and self-fertilization as a result of selection to reduce deleterious reproductive interference. METHODS We characterized variation in herkogamy within and among 25 pure and mixed populations of L. arvensis in its European range and assessed the effectiveness of lateral versus vertical herkogamy in avoiding self-pollen deposition. RESULTS Lateral herkogamy was more effective than vertical herkogamy in limiting self-pollen deposition. In the case of vertical herkogamy, only approach herkogamy was effective. Lineages showed consistent differences in herkogamy traits. In general, angles were smaller for blue than red flowers in most populations, and blue flowers showed approach herkogamy, while red flowers showed predominantly reverse herkogamy. In sympatry, the red lineage showed a reduction of both herkogamy traits while for the blue lineage only lateral herkogamy was reduced. CONCLUSIONS Our results demonstrate that pollen deposition is affected not only by the degree but also the spatial conformation of herkogamy. They also highlight reduced herkogamy as a potential mechanism for promoting reproductive assurance under pollen limitation, as well as for avoiding reproductive interference between genetically divergent lineages.
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Affiliation(s)
- F J Jiménez-López
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Sevilla, Spain
| | - P L Ortiz
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Sevilla, Spain
| | - M Talavera
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Sevilla, Spain
| | - J R Pannell
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - M Arista
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Sevilla, Spain
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23
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Abstract
Range expansions lead to distinctive patterns of genetic variation in populations, even in the absence of selection. These patterns and their genetic consequences have been well studied for populations advancing through successive short-ranged migration events. However, most populations harbor some degree of long-range dispersal, experiencing rare yet consequential migration events over arbitrarily long distances. Although dispersal is known to strongly affect spatial genetic structure during range expansions, the resulting patterns and their impact on neutral diversity remain poorly understood. Here, we systematically study the consequences of long-range dispersal on patterns of neutral variation during range expansion in a class of dispersal models which spans the extremes of local (effectively short-ranged) and global (effectively well-mixed) migration. We find that sufficiently long-ranged dispersal leaves behind a mosaic of monoallelic patches, whose number and size are highly sensitive to the distribution of dispersal distances. We develop a coarse-grained model which connects statistical features of these spatial patterns to the evolution of neutral diversity during the range expansion. We show that growth mechanisms that appear qualitatively similar can engender vastly different outcomes for diversity: Depending on the tail of the dispersal distance distribution, diversity can be either preserved (i.e., many variants survive) or lost (i.e., one variant dominates) at long times. Our results highlight the impact of spatial and migratory structure on genetic variation during processes as varied as range expansions, species invasions, epidemics, and the spread of beneficial mutations in established populations.
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24
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Krueger‐Hadfield SA. What's ploidy got to do with it? Understanding the evolutionary ecology of macroalgal invasions necessitates incorporating life cycle complexity. Evol Appl 2020; 13:486-499. [PMID: 32431731 PMCID: PMC7045718 DOI: 10.1111/eva.12843] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 06/09/2019] [Accepted: 07/06/2019] [Indexed: 01/04/2023] Open
Abstract
Biological invasions represent grave threats to terrestrial, aquatic, and marine ecosystems, but our understanding of the role of evolution during invasions remains rudimentary. In marine environments, macroalgae account for a large percentage of invaders, but their complicated life cycles render it difficult to move methodologies and predictions wholesale from species with a single, free-living ploidy stage, such as plants or animals. In haplodiplontic macroalgae, meiosis and fertilization are spatiotemporally separated by long-lived, multicellular haploid and diploid stages, and gametes are produced by mitosis, not meiosis. As a consequence, there are unique eco-evolutionary constraints that are not typically considered in invasions. First, selfing can occur in both monoicious (i.e., hermaphroditic) and dioicious (i.e., separate sexes) haplodiplontic macroalgae. In the former, fertilization between gametes produced by the same haploid thallus results in instantaneous, genome-wide homozygosity. In the latter, cross-fertilization between separate male and female haploids that share the same diploid parent is analogous to selfing in plants or animals. Separate sexes, therefore, cannot be used as a proxy for outcrossing. Second, selfing likely facilitates invasions (i.e., Baker's law) and the long-lived haploid stage may enable purging of deleterious mutations, further contributing to invasion success. Third, asexual reproduction will result in the dominance of one ploidy and/or sex and the loss of the other(s). Whether or not sexual reproduction can be recovered depends on which stage is maintained. Finally, fourth, haplodiplontic life cycles are predicted to be maintained through niche differentiation in the haploid and diploid stages. Empirical tests are rare, but fundamental to our understanding of macroalgal invasion dynamics. By highlighting these four phenomena, we can build a framework with which to empirically and theoretically address important gaps in the literature on marine evolutionary ecology, of which biological invasions can serve as unnatural laboratories.
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25
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Li Y, van Kleunen M, Stift M. Sibling competition does not magnify inbreeding depression in North American Arabidopsis lyrata. Heredity (Edinb) 2019; 123:723-732. [PMID: 31541202 PMCID: PMC6834581 DOI: 10.1038/s41437-019-0268-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 08/13/2019] [Accepted: 08/13/2019] [Indexed: 11/08/2022] Open
Abstract
About half of all angiosperms have some form of molecular self-incompatibility to promote outcrossing. If self-incompatibility breaks down, inbreeding depression (δ) is the main barrier to the evolution of self-fertilisation (selfing). If inbreeding depression is lower than 50% (δ < 0.5), the inherent transmission advantage of selfers should theoretically drive the evolution of selfing. However, this does not always happen in practice. For example, despite frequent breakdowns of self-incompatibility in North American Arabidopsis lyrata, selfing has only evolved in few populations. This is surprising given that previous inbreeding-depression estimates were well below the 0.5 threshold. Here, we test whether this could be due to underestimation of true inbreeding depression in competition-free environments. Specifically, we tested whether direct competition between crossed and selfed siblings magnified inbreeding-depression estimates in A. lyrata. We found that this was neither the case for belowground nor for aboveground biomass. For reproductive traits, there was hardly any significant inbreeding depression regardless of competition. Combined with previous findings that drought stress and inducing defence also did not magnify inbreeding depression, our results suggest that the relatively low estimates of inbreeding depression for biomass are indeed realistic estimates of the true inbreeding depression in North American A. lyrata.
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Affiliation(s)
- Yan Li
- Ecology, Department of Biology, University of Konstanz, Universitätsstrasse 10, D-78457, Konstanz, Germany.
| | - Mark van Kleunen
- Ecology, Department of Biology, University of Konstanz, Universitätsstrasse 10, D-78457, Konstanz, Germany
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, 318000, Taizhou, China
| | - Marc Stift
- Ecology, Department of Biology, University of Konstanz, Universitätsstrasse 10, D-78457, Konstanz, Germany
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26
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Cutter AD. Reproductive transitions in plants and animals: selfing syndrome, sexual selection and speciation. THE NEW PHYTOLOGIST 2019; 224:1080-1094. [PMID: 31336389 DOI: 10.1111/nph.16075] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 07/17/2019] [Indexed: 05/23/2023]
Abstract
The evolution of predominant self-fertilisation frequently coincides with the evolution of a collection of phenotypes that comprise the 'selfing syndrome', in both plants and animals. Genomic features also display a selfing syndrome. Selfing syndrome traits often involve changes to male and female reproductive characters that were subject to sexual selection and sexual conflict in the obligatorily outcrossing ancestor, including the gametic phase for both plants and animals. Rapid evolution of reproductive traits, due to both relaxed selection and directional selection under the new status of predominant selfing, lays the genetic groundwork for reproductive isolation. Consequently, shifts in sexual selection pressures coupled to transitions to selfing provide a powerful paradigm for investigating the speciation process. Plant and animal studies, however, emphasise distinct selective forces influencing reproductive-mode transitions: genetic transmission advantage to selfing or reproductive assurance outweighing the costs of inbreeding depression vs the costs of males and meiosis. Here, I synthesise links between sexual selection, evolution of selfing and speciation, with particular focus on identifying commonalities and differences between plant and animal systems and pointing to areas warranting further synergy.
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Affiliation(s)
- Asher D Cutter
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON, M5S 3B2, Canada
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Baldwin SJ, Schoen DJ. Inbreeding depression is difficult to purge in self-incompatible populations of Leavenworthia alabamica. THE NEW PHYTOLOGIST 2019; 224:1330-1338. [PMID: 31131900 DOI: 10.1111/nph.15963] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 05/20/2019] [Indexed: 06/09/2023]
Abstract
The extent to which inbreeding depression can be purged is a major determinant of mating system evolution and is important to conservation and crop improvement. Studies of inbreeding depression purging have not been conducted in self-incompatible plants before. An experimental ('ancestral') treatment was first created from self-incompatible plants of Leavenworthia alabamica. Lines derived from this population were maintained by self-pollination for three generations in the attempt to create a 'purged' population with fewer recessive, deleterious mutations of large effect. Fitness components and the frequency of malformed phenotypes were monitored in progeny derived from selfing and outcrossing in the ancestral and purged treatments. Fitness component means and inbreeding depression were largely unchanged by three generations of forced self-pollination, and there was no reduction in the frequency of plants exhibiting malformed phenotypes. Our findings indicate that inbreeding depression in this species is largely a result of mutations of mild effect, consistent with the observation that self-incompatibility is maintained in most populations of L. alabamica, despite the presence of genetic variants with weaker self-incompatibility. Moreover, although population theory suggests that deleterious mutations of large effect should be sheltered from selection in the region of self-incompatibility locus, our results do not support this prediction.
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Affiliation(s)
- Sarah J Baldwin
- Department of Biology, McGill University, 1205 Avenue Docteur Penfield, Montreal, QC, H3A 1B1, Canada
| | - Daniel J Schoen
- Department of Biology, McGill University, 1205 Avenue Docteur Penfield, Montreal, QC, H3A 1B1, Canada
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Koski MH, Layman NC, Prior CJ, Busch JW, Galloway LF. Selfing ability and drift load evolve with range expansion. Evol Lett 2019; 3:500-512. [PMID: 31636942 PMCID: PMC6791181 DOI: 10.1002/evl3.136] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 08/09/2019] [Accepted: 08/11/2019] [Indexed: 12/16/2022] Open
Abstract
Colonization at expanding range edges often involves few founders, reducing effective population size. This process can promote the evolution of self-fertilization, but implicating historical processes as drivers of trait evolution is often difficult and requires an explicit model of biogeographic history. In plants, contemporary limits to outcrossing are often invoked as evolutionary drivers of self-fertilization, but historical expansions may shape mating system diversity, with leading-edge populations evolving elevated selfing ability. In a widespread plant, Campanula americana, we identified a glacial refugium in the southern Appalachian Mountains from spatial patterns of genetic drift among 24 populations. Populations farther from this refugium have smaller effective sizes and fewer rare alleles. They also displayed elevated heterosis in among-population crosses, reflecting the accumulation of deleterious mutations during range expansion. Although populations with elevated heterosis had reduced segregating mutation load, the magnitude of inbreeding depression lacked geographic pattern. The ability to self-fertilize was strongly positively correlated with the distance from the refugium and mutation accumulation-a pattern that contrasts sharply with contemporary mate and pollinator limitation. In this and other species, diversity in sexual systems may reflect the legacy of evolution in small, colonizing populations, with little or no relation to the ecology of modern populations.
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Affiliation(s)
- Matthew H Koski
- Department of Biology University of Virginia Charlottesville Virginia 22902.,Current Address: Department of Biological Sciences Clemson University Clemson SC 29631
| | - Nathan C Layman
- School of Biological Sciences Washington State University Pullman Washington 99164
| | - Carly J Prior
- School of Biological Sciences Washington State University Pullman Washington 99164
| | - Jeremiah W Busch
- School of Biological Sciences Washington State University Pullman Washington 99164
| | - Laura F Galloway
- Department of Biology University of Virginia Charlottesville Virginia 22902
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Casellas J, Ibáñez-Escriche N, Varona L, Rosas JP, Noguera JL. Inbreeding depression load for litter size in Entrepelado and Retinto Iberian pig varieties1. J Anim Sci 2019; 97:1979-1986. [PMID: 30869129 DOI: 10.1093/jas/skz084] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 03/12/2019] [Indexed: 01/17/2023] Open
Abstract
Individual-specific hidden inbreeding depression load (IDL) can be accounted for in livestock populations by appropriate best linear unbiased prediction approaches. This genetic effect has a recessive pattern and reveals when inherited in terms of identity-by-descent. Nevertheless, IDL inherits as a pure additive genetic background and can be selected using standard breeding values. The main target of this research was to evaluate IDL for litter size in 2 Iberian pig varieties (Entrepelado and Retinto) from a commercial breeding-stock. Analyses were performed on the total number of piglets born (both alive and dead) and used data from 3,200 (8.02 ± 0.04 piglets/litter) Entrepelado and 4,744 Retinto litters (8.40 ± 0.03 piglets/litter). Almost 50% of Entrepelado sows were inbred (1.7% to 25.0%), whereas this percentage reduced to 37.4% in the Retinto variety (0.2% to 25.0%). The analytical model was solved by Bayesian inference and accounted for 2 systematic effects (sow age and breed/variety of the artificial insemination boar), 2 permanent environmental effects (herd-year-season and sow), and 2 genetic effects (IDL and infinitesimal additive). In terms of posterior means (PM), additive genetic and IDL variances were similar in the Entrepelado variety (PM, 0.68 vs. 0.76 piglets2, respectively) and their 95% credibility intervals (95CI) overlapped, although without including zero (0.38 to 0.94 vs. 0.15 to 1.31 piglets2, respectively). The same pattern revealed in the Retinto variety, with IDL variance (PM, 0.41 piglets2; 95CI, 0.07 to 0.88 piglets2) slightly larger than the additive genetic variance (PM, 0.37 piglets2; 95CI, 0.16 to 0.59 piglets2). The relevance of IDL was also checked by a Bayes factor and the deviance information criterion, the model including this effect being clearly favored in both cases. Although the analysis assumed null genetic covariance between IDL and infinitesimal additive effects, a moderate negative correlation (-0.31) was suggested when plotting the PM of breeding values in the Entrepelado variety; a negative genetic trend for IDL was also revealed in this Iberian pig variety (-0.25 piglets for 100% inbred offspring of individuals born in 2014), whereas no trend was detected in Retinto breeding-stock. Those were the first estimates of IDL in a commercial livestock population, they giving evidence of a relevant genetic background with potential consequences on the reproductive performance of Iberian sows.
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Affiliation(s)
- Joaquim Casellas
- Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | | | - Luis Varona
- Departamento de Anatomía Embriología y Genética Animal, Universidad de Zaragoza, Zaragoza, Spain
| | - Juan P Rosas
- Programa de Mejora Genética "Castúa," INGA FOOD S.A. (Nutreco Group), Almendralejo, Spain
| | - Jose L Noguera
- Genètica i Millora Animal, Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Lleida, Spain
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Ma WJ, Santos del Blanco L, Pannell JR. A new biological species in the Mercurialis annua polyploid complex: functional divergence in inflorescence morphology and hybrid sterility. ANNALS OF BOTANY 2019; 124:165-178. [PMID: 31098610 PMCID: PMC6676388 DOI: 10.1093/aob/mcz058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 03/27/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND AND AIMS Polyploidy has played a major role in the origin of new plant species, probably because of the expansion of polyploid populations in the species' ecological niche, and because reproductive isolation can be established between a new polyploid population and its diploid progenitor species. It is well established that most polyploid species are polyphyletic, with multiple independent origins, and that polyploid genomes may undergo rapid change after their duplication and hybridization associated with their origin. We considered whether multiple independent origins and rapid genomic change might lead to reproductive isolation between polyploid populations of the same ploidy but with potentially different evolutionary histories. METHODS We tested our hypothesis by assessing differences in DNA content and morphology, the evolution of reproductive isolation, and the phylogenetic placement of two broadly sympatric hexaploid lineages of the wind-pollinated annual plant Mercurialis annua hitherto regarded as populations of the same species. KEY RESULTS The two hexaploid lineages of M. annua have slightly divergent DNA content, and distinct inflorescence morphology. They also fall into largely different clades of a chloroplast phylogeny and are reproductively isolated from one another. CONCLUSIONS The distinct evolutionary histories of the two hexaploid lineages of M. annua have contributed to the remarkable reproductive diversity of the species complex. It seems likely that reproductive interference between them will eventually lead to the displacement of one lineage by the other via pollen swamping. Thus, whereas polyploidization can contribute to speciation, diversification might also be compromised by reproductive interference.
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Affiliation(s)
- Wen-Juan Ma
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | | | - John R Pannell
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
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31
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Voillemot M, Encinas-Viso F, Pannell JR. Rapid loss of self-incompatibility in experimental populations of the perennial outcrossing plant Linaria cavanillesii. Evolution 2019; 73:913-926. [PMID: 30874301 DOI: 10.1111/evo.13721] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 02/18/2019] [Indexed: 11/30/2022]
Abstract
Transitions from self-incompatibility to self-compatibility in angiosperms may be frequently driven by selection for reproductive assurance when mates or pollinators are rare, and are often succeeded by loss of inbreeding depression by purging. Here, we use experimental evolution to investigate the spread of self-compatibility from one such population of the perennial plant Linaria cavanillesii into self-incompatible (SI) populations that still have high inbreeding depression. We introduced self-compatible (SC) individuals at different frequencies into replicate experimental populations of L. cavanillesii that varied in access to pollinators. Our experiment revealed a rapid shift to self-compatibility in all replicates, driven by both greater seed set and greater outcross siring success of SC individuals. We discuss our results in the light of computer simulations that confirm the tendency of self-compatibility to spread into SI populations under the observed conditions. Our study illustrates the ease with which self-compatibility can spread among populations, a requisite for species-wide transitions from self-incompatibility to self-compatibility.
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Affiliation(s)
- Marie Voillemot
- Department of Ecology and Evolution, Biophore/Sorge, University of Lausanne, 1015, Lausanne, Switzerland
| | - Francisco Encinas-Viso
- Centre for Australian National Biodiversity Research, CSIRO, Canberra, ACT 2601, Australia
| | - John R Pannell
- Department of Ecology and Evolution, Biophore/Sorge, University of Lausanne, 1015, Lausanne, Switzerland
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32
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Santos Del Blanco L, Tudor E, Pannell JR. Low siring success of females with an acquired male function illustrates the legacy of sexual dimorphism in constraining the breakdown of dioecy. Ecol Lett 2019; 22:486-497. [PMID: 30618173 PMCID: PMC6850444 DOI: 10.1111/ele.13207] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 10/24/2018] [Accepted: 11/20/2018] [Indexed: 01/03/2023]
Abstract
Dioecy has often broken down in flowering plants, yielding functional hermaphroditism. We reasoned that evolutionary transitions from dioecy to functional hermaphroditism must overcome an inertia of sexual dimorphism, because modified males or females will express the opposite sexual function for which their phenotypes have been optimised. We tested this prediction by assessing the siring success of monoecious individuals of the plant Mercurialis annua with an acquired male function but that are phenotypically still female‐like. We found that pollen dispersed by female‐like monoecious individuals was ~ 1/3 poorer at siring outcrossed offspring than pollen from monoecious individuals with an alternative male‐like inflorescence. We conclude that whereas dioecy might evolve from functional hermaphroditism by conferring upon individuals certain benefits of sexual specialisation, reversion from a strategy of separate sexes to one of combined sexes must overcome constraints imposed by the advantages of sexual dimorphism. The breakdown of dioecy must therefore often be limited to situations in which outcrossing cannot be maintained and where selection favours a capacity for inbreeding by functional hermaphrodites.
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Affiliation(s)
- Luis Santos Del Blanco
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, 1015, Lausanne, Switzerland
| | - Eleri Tudor
- Department of Plant Sciences, University of Oxford, Oxford, OX1 3RB, UK
| | - John R Pannell
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, 1015, Lausanne, Switzerland
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33
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Layman NC, Busch JW. Bottlenecks and inbreeding depression in autotetraploids. Evolution 2018; 72:2025-2037. [PMID: 30136722 DOI: 10.1111/evo.13587] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 08/14/2018] [Indexed: 12/30/2022]
Abstract
Inbreeding depression is dependent on the ploidy of populations and can inhibit the evolution of selfing. While polyploids should generally harbor less inbreeding depression than diploids at equilibrium, it has been unclear whether this pattern holds in non-equilibrium conditions following bottlenecks. We use stochastic individual-based simulations to determine the effects of population bottlenecks on inbreeding depression in diploids and autotetraploids, in addition to cases where neo-autotetraploids form from the union of unreduced gametes. With a ploidy-independent dominance function based on enzyme kinetics, inbreeding depression is generally lower in autotetraploids for fully and partially recessive mutations. Due to the sampling of more chromosomes during reproduction, bottlenecks generally reduce inbreeding depression to a lesser extent in autotetraploids. All else being equal, population bottlenecks may have ploidy-dependent effects for another reason-in some cases matings between close relatives temporarily increase inbreeding depression in autotetraploids by increasing the frequency of the heterozygous genotype harboring the most harmful mutations. When neo-autotetraploids are formed by few individuals, inbreeding depression is dramatically reduced, given extensive masking of harmful mutations following whole genome duplication. This effect persists as nascent tetraploids reach mutation-selection-drift balance, providing a transient period of permissive conditions favoring the evolution of selfing.
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Affiliation(s)
- Nathan C Layman
- School of Biological Sciences, Washington State University, Pullman, Washington 99164
| | - Jeremiah W Busch
- School of Biological Sciences, Washington State University, Pullman, Washington 99164
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34
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Casellas J. On individual-specific prediction of hidden inbreeding depression load. J Anim Breed Genet 2017; 135:37-44. [PMID: 29230876 DOI: 10.1111/jbg.12308] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 11/17/2017] [Indexed: 11/29/2022]
Abstract
Inbreeding depression is caused by increased homozygosity in the genome and merges two genetic mechanisms, a higher impact from recessive mutations and the waste of overdominance contributions. It is of major concern for the conservation of endangered populations of plants and animals, as major abnormalities are more frequent in inbred families than in outcrosses. Nevertheless, we lack appropriate analytical methods to estimate the hidden inbreeding depression load (IDL) in the genome of each individual. Here, a new mixed linear model approach has been developed to account for the inbreeding depression-related background of each individual in the pedigree. Within this context, inbred descendants contributed relevant information to predict the IDL contained in the genome of a given ancestor; moreover, known relationships spread these predictions to the remaining individuals in the pedigree, even if not contributing inbred offspring. Results obtained from the analysis of weaning weight in the MARET rabbit population demonstrated that the genetic background of inbreeding depression distributed heterogeneously across individuals and inherited generation by generation. Moreover, this approach was clearly preferred in terms of model fit and complexity when compared with classical approaches to inbreeding depression. This methodology must be viewed as a new tool for a better understanding of inbreeding in domestic and wild populations.
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Affiliation(s)
- J Casellas
- Grup de Recerca en Millora Genètica Molecular Veterinària, Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona, Bellaterra, Spain
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35
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Voillemot M, Rougemont Q, Roux C, Pannell JR. The divergence history of the perennial plant Linaria cavanillesii
confirms a recent loss of self-incompatibility. J Evol Biol 2017; 31:136-147. [DOI: 10.1111/jeb.13209] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 11/03/2017] [Accepted: 11/07/2017] [Indexed: 11/30/2022]
Affiliation(s)
- M. Voillemot
- Department of Ecology and Evolution; Biophore/Sorge; University of Lausanne; Lausanne Switzerland
| | - Q. Rougemont
- Institut de Biologie Intégrative et des Systèmes (IBIS); University of Laval; Québec City Québec Canada
| | - C. Roux
- Department of Ecology and Evolution; Biophore/Sorge; University of Lausanne; Lausanne Switzerland
- Unité Evo-Eco-Paléo (EEP) - UMR 8198; CNRS; Université de Lille Sciences et Technologies; Villeneuve d'Ascq Cedex France
| | - J. R. Pannell
- Department of Ecology and Evolution; Biophore/Sorge; University of Lausanne; Lausanne Switzerland
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36
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Barrett SC, Harder LD. The Ecology of Mating and Its Evolutionary Consequences in Seed Plants. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2017. [DOI: 10.1146/annurev-ecolsys-110316-023021] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Spencer C.H. Barrett
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada
| | - Lawrence D. Harder
- Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada
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37
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Koski MH, Grossenbacher DL, Busch JW, Galloway LF. A geographic cline in the ability to self-fertilize is unrelated to the pollination environment. Ecology 2017; 98:2930-2939. [PMID: 28869778 DOI: 10.1002/ecy.2001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/22/2017] [Accepted: 08/18/2017] [Indexed: 01/14/2023]
Abstract
The reproductive assurance (RA) hypothesis predicts that the ability to autonomously self-fertilize should be favored in environments where a lack of mates or pollinators limits outcross reproduction. Because such limits to outcrossing are predicted to be most severe at range edges, elevated autonomy in peripheral populations is often attributed to RA. We test this hypothesis in 24 populations spanning the range of Campanula americana, including sampling at the range interior and three geographic range edges. We scored autonomous fruit set in a pollinator-free environment and detected clinal variation-autonomy increased linearly from the southern to the northern edge, and from the eastern to the western edge. We then address whether the cline reflects the contemporary pollination environment. We measured population size, plant density, pollinator visitation, outcross pollen limitation and RA in natural populations over two years. Most populations were pollen limited, and those that experienced higher visitation rates by bumblebees had reduced pollen limitation. Reproductive assurance, however, was generally low across populations and was unrelated to pollen limitation or autonomy. Neither pollen limitation nor RA displayed geographic clines. Finally, autonomy was not associated with pollinator visitation rates or mate availability. Thus, the data do not support the RA hypothesis; clinal variation in autonomy is unrelated to the current pollination environment. Therefore, geographic patterns of autonomy are likely the result of historical processes rather than contemporary natural selection for RA.
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Affiliation(s)
- Matthew H Koski
- Department of Biology, University of Virginia, PO Box 400328, Charlottesville, Virginia, 22904, USA
| | - Dena L Grossenbacher
- School of Biological Sciences, Washington State University, PO Box 644236, Pullman, Washington, 99164-4236, USA.,Department of Biology, California Polytechnic State University, 1 Grand Avenue, San Luis Obispo, California, 93407, USA
| | - Jeremiah W Busch
- School of Biological Sciences, Washington State University, PO Box 644236, Pullman, Washington, 99164-4236, USA
| | - Laura F Galloway
- Department of Biology, University of Virginia, PO Box 400328, Charlottesville, Virginia, 22904, USA
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38
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Carleial S, van Kleunen M, Stift M. Relatively weak inbreeding depression in selfing but also in outcrossing populations of North American Arabidopsis lyrata. J Evol Biol 2017; 30:1994-2004. [PMID: 28833878 DOI: 10.1111/jeb.13169] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 08/01/2017] [Accepted: 08/09/2017] [Indexed: 01/28/2023]
Abstract
Hermaphroditic plants can potentially self-fertilize, but most possess adaptations that promote outcrossing. However, evolutionary transitions to higher selfing rates are frequent. Selfing comes with a transmission advantage over outcrossing, but self-progeny may suffer from inbreeding depression, which forms the main barrier to the evolution of higher selfing rates. Here, we assessed inbreeding depression in the North American herb Arabidopsis lyrata, which is normally self-incompatible, with a low frequency of self-compatible plants. However, a few populations have become fixed for self-compatibility and have high selfing rates. Under greenhouse conditions, we estimated mean inbreeding depression per seed (based on cumulative vegetative performance calculated as the product of germination, survival and aboveground biomass) to be 0.34 for six outcrossing populations, and 0.26 for five selfing populations. Exposing plants to drought and inducing defences with jasmonic acid did not magnify these estimates. For outcrossing populations, however, inbreeding depression per seed may underestimate true levels of inbreeding depression, because self-incompatible plants showed strong reductions in seed set after (enforced) selfing. Inbreeding-depression estimates incorporating seed set averaged 0.63 for outcrossing populations (compared to 0.30 for selfing populations). However, this is likely an overestimate because exposing plants to 5% CO2 to circumvent self-incompatibility to produce selfed seed might leave residual effects of self-incompatibility that contribute to reduced seed set. Nevertheless, our estimates of inbreeding depression were clearly lower than previous estimates based on the same performance traits in outcrossing European populations of A. lyrata, which may help explain why selfing could evolve in North American A. lyrata.
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Affiliation(s)
- S Carleial
- Ecology, Department of Biology, University of Konstanz, Konstanz, Germany
| | - M van Kleunen
- Ecology, Department of Biology, University of Konstanz, Konstanz, Germany.,Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou, China
| | - M Stift
- Ecology, Department of Biology, University of Konstanz, Konstanz, Germany
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Rafajlović M, Kleinhans D, Gulliksson C, Fries J, Johansson D, Ardehed A, Sundqvist L, Pereyra RT, Mehlig B, Jonsson PR, Johannesson K. Neutral processes forming large clones during colonization of new areas. J Evol Biol 2017; 30:1544-1560. [PMID: 28557006 DOI: 10.1111/jeb.13124] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 04/28/2017] [Accepted: 05/24/2017] [Indexed: 01/16/2023]
Abstract
In species reproducing both sexually and asexually clones are often more common in recently established populations. Earlier studies have suggested that this pattern arises due to natural selection favouring generally or locally successful genotypes in new environments. Alternatively, as we show here, this pattern may result from neutral processes during species' range expansions. We model a dioecious species expanding into a new area in which all individuals are capable of both sexual and asexual reproduction, and all individuals have equal survival rates and dispersal distances. Even under conditions that favour sexual recruitment in the long run, colonization starts with an asexual wave. After colonization is completed, a sexual wave erodes clonal dominance. If individuals reproduce more than one season, and with only local dispersal, a few large clones typically dominate for thousands of reproductive seasons. Adding occasional long-distance dispersal, more dominant clones emerge, but they persist for a shorter period of time. The general mechanism involved is simple: edge effects at the expansion front favour asexual (uniparental) recruitment where potential mates are rare. Specifically, our model shows that neutral processes (with respect to genotype fitness) during the population expansion, such as random dispersal and demographic stochasticity, produce genotype patterns that differ from the patterns arising in a selection model. The comparison with empirical data from a post-glacially established seaweed species (Fucus radicans) shows that in this case, a neutral mechanism is strongly supported.
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Affiliation(s)
- M Rafajlović
- Department of Physics, University of Gothenburg, Gothenburg, Sweden
- The Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
| | - D Kleinhans
- The Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - C Gulliksson
- Department of Applied Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - J Fries
- Department of Applied Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - D Johansson
- The Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
- Department of Biological and Environmental Sciences, University of Gothenburg, Tjärnö, Strömstad, Sweden
| | - A Ardehed
- The Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
- Department of Biological and Environmental Sciences, University of Gothenburg, Tjärnö, Strömstad, Sweden
| | - L Sundqvist
- The Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - R T Pereyra
- The Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
- Department of Marine Sciences, University of Gothenburg, Tjärnö, Strömstad, Sweden
| | - B Mehlig
- Department of Physics, University of Gothenburg, Gothenburg, Sweden
- The Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
| | - P R Jonsson
- The Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
- Department of Marine Sciences, University of Gothenburg, Tjärnö, Strömstad, Sweden
| | - K Johannesson
- The Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
- Department of Marine Sciences, University of Gothenburg, Tjärnö, Strömstad, Sweden
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40
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Range Expansion Compromises Adaptive Evolution in an Outcrossing Plant. Curr Biol 2017; 27:2544-2551.e4. [DOI: 10.1016/j.cub.2017.07.007] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 05/22/2017] [Accepted: 07/04/2017] [Indexed: 01/04/2023]
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Grossenbacher DL, Brandvain Y, Auld JR, Burd M, Cheptou PO, Conner JK, Grant AG, Hovick SM, Pannell JR, Pauw A, Petanidou T, Randle AM, Rubio de Casas R, Vamosi J, Winn A, Igic B, Busch JW, Kalisz S, Goldberg EE. Self-compatibility is over-represented on islands. THE NEW PHYTOLOGIST 2017; 215:469-478. [PMID: 28382619 DOI: 10.1111/nph.14534] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 02/20/2017] [Indexed: 06/07/2023]
Abstract
Because establishing a new population often depends critically on finding mates, individuals capable of uniparental reproduction may have a colonization advantage. Accordingly, there should be an over-representation of colonizing species in which individuals can reproduce without a mate, particularly in isolated locales such as oceanic islands. Despite the intuitive appeal of this colonization filter hypothesis (known as Baker's law), more than six decades of analyses have yielded mixed findings. We assembled a dataset of island and mainland plant breeding systems, focusing on the presence or absence of self-incompatibility. Because this trait enforces outcrossing and is unlikely to re-evolve on short timescales if it is lost, breeding system is especially likely to reflect the colonization filter. We found significantly more self-compatible species on islands than mainlands across a sample of > 1500 species from three widely distributed flowering plant families (Asteraceae, Brassicaceae and Solanaceae). Overall, 66% of island species were self-compatible, compared with 41% of mainland species. Our results demonstrate that the presence or absence of self-incompatibility has strong explanatory power for plant geographical patterns. Island floras around the world thus reflect the role of a key reproductive trait in filtering potential colonizing species in these three plant families.
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Affiliation(s)
- Dena L Grossenbacher
- Department of Biology, California Polytechnic State University, San Luis Obispo, CA, 93407, USA
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN, 55108, USA
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Yaniv Brandvain
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Josh R Auld
- Department of Biology, West Chester University, West Chester, PA, 19383, USA
| | - Martin Burd
- School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - Pierre-Olivier Cheptou
- CEFE UMR 5175, CNRS, Université de Montpellier, Université Paul-Valery Montpellier, EPHE, CEFE, 34293, Montpellier Cedex 05, France
| | - Jeffrey K Conner
- Kellogg Biological Station and Department of Plant Biology, Michigan State University, Hickory Corners, MI, 49060, USA
| | - Alannie G Grant
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Stephen M Hovick
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, OH, 43210, USA
| | - John R Pannell
- Department of Ecology and Evolution, University of Lausanne, 1015, Lausanne, Switzerland
| | - Anton Pauw
- Department of Botany and Zoology, Stellenbosch University, Stellenbosch, 7602, South Africa
| | - Theodora Petanidou
- Laboratory of Biogeography and Ecology, Department of Geography, University of the Aegean, 81100, Mytilene, Lesvos, Greece
| | - April M Randle
- Department of Environmental Science, University of San Francisco, San Francisco, CA, 94117, USA
| | - Rafael Rubio de Casas
- Departmento Ecología, Facultad de Ciencias, Universidad de Granada, Granada, UGR, 18071, Granada, Spain
| | - Jana Vamosi
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada, T2N 1N4
| | - Alice Winn
- Department of Biological Science, Florida State University, Tallahassee, FL, 32306, USA
| | - Boris Igic
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Jeremiah W Busch
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Susan Kalisz
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Emma E Goldberg
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Saint Paul, MN, 55108, USA
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Circular mating as an option for the genetic management of captive populations: response to Caballero et al. Heredity (Edinb) 2017; 119:49-50. [PMID: 28327580 DOI: 10.1038/hdy.2017.16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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Käfer J, Marais GAB, Pannell JR. On the rarity of dioecy in flowering plants. Mol Ecol 2017; 26:1225-1241. [PMID: 28101895 DOI: 10.1111/mec.14020] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 12/27/2016] [Accepted: 12/28/2016] [Indexed: 01/21/2023]
Abstract
Dioecy, the coexistence of separate male and female individuals in a population, is a rare but phylogenetically widespread sexual system in flowering plants. While research has concentrated on why and how dioecy evolves from hermaphroditism, the question of why dioecy is rare, despite repeated transitions to it, has received much less attention. Previous phylogenetic and theoretical studies have suggested that dioecy might be an evolutionary dead end. However, recent research indicates that the phylogenetic support for this hypothesis is attributable to a methodological bias and that there is no evidence for reduced diversification in dioecious angiosperms. The relative rarity of dioecy thus remains a puzzle. Here, we review evidence for the hypothesis that dioecy might be rare not because it is an evolutionary dead end, but rather because it easily reverts to hermaphroditism. We review what is known about transitions between hermaphroditism and dioecy, and conclude that there is an important need to consider more widely the possibility of transitions away from dioecy, both from an empirical and a theoretical point of view, and by combining tools from molecular evolution and insights from ecology.
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Affiliation(s)
- Jos Käfer
- Laboratoire de Biométrie et Biologie Evolutive, CNRS, UMR 5558, Université Lyon 1, Bât. Grégor Mendel 43, bd du 11 novembre 1918, 69622, Villeurbanne cedex, France
| | - Gabriel A B Marais
- Laboratoire de Biométrie et Biologie Evolutive, CNRS, UMR 5558, Université Lyon 1, Bât. Grégor Mendel 43, bd du 11 novembre 1918, 69622, Villeurbanne cedex, France
| | - John R Pannell
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, 1015, Lausanne, Switzerland
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Quaglietti B, Tamisier L, Groussier G, Fleisch A, Le Goff I, Ris N, Kreiter P, Fauvergue X, Malausa T. No inbreeding depression in laboratory-reared individuals of the parasitoid wasp Allotropa burrelli. Ecol Evol 2017; 7:964-973. [PMID: 28168032 PMCID: PMC5288250 DOI: 10.1002/ece3.2643] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 11/03/2016] [Accepted: 11/08/2016] [Indexed: 11/13/2022] Open
Abstract
Inbreeding depression is a major concern in almost all human activities relating to plant and animal breeding. The biological control of pests with natural enemies is no exception, because populations of biocontrol agents experience a series of bottlenecks during importation, rearing, and introduction. A classical biological control program for the Comstock mealybug Pseudococcus comstocki (Hemiptera: Pseudococcidae) was initiated in France in 2008, based on the introduction of an exotic parasitoid, Allotropa burrelli Mues. (Hymenoptera: Platygastridae), a haplodiploid parasitoid imported from Japan. We evaluated the sensitivity of A. burrelli to inbreeding, to optimize rearing and release strategies. We compared several morphological and life‐history traits between the offspring of siblings and the offspring of unrelated parents. We took into account the low level of genetic variability due to the relatively small size of laboratory‐reared populations by contrasting two types of pedigree: one for individuals from a strain founded from a single field population, and the other generated by hybridizing individuals from two strains founded from two highly differentiated populations. Despite this careful design, we obtained no evidence for a negative impact of inbreeding on laboratory‐reared A. burrelli. We discussed the results in light of haplodiploid sex determination and parasitoid mating systems, and classical biological control practices.
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Affiliation(s)
- Bastien Quaglietti
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Lucie Tamisier
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Géraldine Groussier
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Alexandre Fleisch
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Isabelle Le Goff
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Nicolas Ris
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Philippe Kreiter
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Xavier Fauvergue
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Thibaut Malausa
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
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Carvalho CDS, Ballesteros-Mejia L, Ribeiro MC, Côrtes MC, Santos AS, Collevatti RG. Climatic stability and contemporary human impacts affect the genetic diversity and conservation status of a tropical palm in the Atlantic Forest of Brazil. CONSERV GENET 2017. [DOI: 10.1007/s10592-016-0921-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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46
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Broz AK, Randle AM, Sianta SA, Tovar-Méndez A, McClure B, Bedinger PA. Mating system transitions in Solanum habrochaites impact interactions between populations and species. THE NEW PHYTOLOGIST 2017; 213:440-454. [PMID: 27516156 DOI: 10.1111/nph.14130] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 07/01/2016] [Indexed: 05/23/2023]
Abstract
In plants, transitions in mating system from outcrossing to self-fertilization are common; however, the impact of these transitions on interspecific and interpopulation reproductive barriers is not fully understood. We examined the consequences of mating system transition for reproductive barriers in 19 populations of the wild tomato species Solanum habrochaites. We identified S. habrochaites populations with self-incompatible (SI), self-compatible (SC) and mixed population (MP) mating systems, and characterized pollen-pistil interactions among S. habrochaites populations and between S. habrochaites and other tomato species. We examined the relationship between mating system, floral morphology, interspecific and interpopulation compatibility and pistil SI factors. We documented five distinct phenotypic groups by combining reproductive behavior with molecular data. Transitions from SI to MP were not associated with weakened interspecific reproductive barriers or loss of known pistil SI factors. However, transitions to SC at the northern range margin were accompanied by loss of S-RNase, smaller flowers, and weakened (or absent) interspecific pollen-pistil barriers. Finally, we identified a subset of SC populations that exhibited a partial interpopulation reproductive barrier with central SI populations. Our results support the hypothesis that shifts in mating system, followed by additional loss-of-function mutations, impact reproductive barriers within and between species.
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Affiliation(s)
- Amanda K Broz
- Department of Biology, Colorado State University, Fort Collins, CO, 80523-1878, USA
| | - April M Randle
- Department of Biology, Colorado State University, Fort Collins, CO, 80523-1878, USA
- Department of Environmental Science, University of San Francisco, San Francisco, CA, 94117, USA
| | - Shelley A Sianta
- Department of Biology, Colorado State University, Fort Collins, CO, 80523-1878, USA
| | | | - Bruce McClure
- Department of Biochemistry, University of Missouri-Columbia, Columbia, MO, 65211, USA
| | - Patricia A Bedinger
- Department of Biology, Colorado State University, Fort Collins, CO, 80523-1878, USA
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47
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Michaelides SN, While GM, Zajac N, Aubret F, Calsbeek B, Sacchi R, Zuffi MAL, Uller T. Loss of genetic diversity and increased embryonic mortality in non-native lizard populations. Mol Ecol 2016; 25:4113-25. [DOI: 10.1111/mec.13755] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 06/26/2016] [Accepted: 06/27/2016] [Indexed: 12/01/2022]
Affiliation(s)
- Sozos N. Michaelides
- Edward Grey Institute; Department of Zoology; University of Oxford; South Parks Rd OX1 3PS Oxford UK
| | - Geoffrey M. While
- Edward Grey Institute; Department of Zoology; University of Oxford; South Parks Rd OX1 3PS Oxford UK
- School of Biological Sciences; University of Tasmania; PO Box 55 Hobart Tas. 7001 Australia
| | - Natalia Zajac
- Edward Grey Institute; Department of Zoology; University of Oxford; South Parks Rd OX1 3PS Oxford UK
| | - Fabien Aubret
- Station d'Ecologie Expérimentale du CNRS à Moulis; 09200 Moulis France
| | - Brittny Calsbeek
- Department of Biological Sciences; Dartmouth College; Hanover NH 03755 USA
| | - Roberto Sacchi
- Dipartimento Sci Terra & Ambiente, Lab Ecoetol; Università di Pavia; I-27100 Pavia Italy
| | - Marco A. L. Zuffi
- Museo di Storia Naturale; Università di Pisa; Via Roma, 79 56011 Calci Pisa Italy
| | - Tobias Uller
- Edward Grey Institute; Department of Zoology; University of Oxford; South Parks Rd OX1 3PS Oxford UK
- Department of Biology; Lund University; Sölvegatan 37 SE 223 62 Lund Sweden
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Salces-Castellano A, Paniw M, Casimiro-Soriguer R, Ojeda F. Attract them anyway: benefits of large, showy flowers in a highly autogamous, carnivorous plant species. AOB PLANTS 2016; 8:plw017. [PMID: 26977052 PMCID: PMC4832431 DOI: 10.1093/aobpla/plw017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 03/03/2016] [Indexed: 05/06/2023]
Abstract
Reproductive biology of carnivorous plants has largely been studied on species that rely on insects as pollinators and prey, creating potential conflicts. Autogamous pollination, although present in some carnivorous species, has received less attention. In angiosperms, autogamous self-fertilization is expected to lead to a reduction in flower size, thereby reducing resource allocation to structures that attract pollinators. A notable exception is the carnivorous pyrophyteDrosophyllum lusitanicum(Drosophyllaceae), which has been described as an autogamous selfing species but produces large, yellow flowers. Using a flower removal and a pollination experiment, we assessed, respectively, whether large flowers in this species may serve as an attracting device to prey insects or whether previously reported high selfing rates for this species in peripheral populations may be lower in more central, less isolated populations. We found no differences between flower-removed plants and intact, flowering plants in numbers of prey insects trapped. We also found no indication of reduced potential for autogamous reproduction, in terms of either seed set or seed size. However, our results showed significant increases in seed set of bagged, hand-pollinated flowers and unbagged flowers exposed to insect visitation compared with bagged, non-manipulated flowers that could only self-pollinate autonomously. Considering that the key life-history strategy of this pyrophytic species is to maintain a viable seed bank, any increase in seed set through insect pollinator activity would increase plant fitness. This in turn would explain the maintenance of large, conspicuous flowers in a highly autogamous, carnivorous plant.
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Affiliation(s)
- A Salces-Castellano
- Departamento de Biología and IVAGRO, Universidad de Cádiz, Campus Río San Pedro, E-11510 Puerto Real, Spain Present address: IPNA-CSIC, C/Astrofísico Francisco Sánchez 3, 38206-La Laguna, Tenerife, Canary Islands, Spain
| | - M Paniw
- Departamento de Biología and IVAGRO, Universidad de Cádiz, Campus Río San Pedro, E-11510 Puerto Real, Spain
| | - R Casimiro-Soriguer
- Departamento de Biología and IVAGRO, Universidad de Cádiz, Campus Río San Pedro, E-11510 Puerto Real, Spain
| | - F Ojeda
- Departamento de Biología and IVAGRO, Universidad de Cádiz, Campus Río San Pedro, E-11510 Puerto Real, Spain
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Peischl S, Kirkpatrick M, Excoffier L. Expansion load and the evolutionary dynamics of a species range. Am Nat 2016; 185:E81-93. [PMID: 25811091 DOI: 10.1086/680220] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Expanding populations incur a mutation burden, the so-called expansion load. Using a mixture of individual-based simulations and analytical modeling, we study the expansion load process in models where population growth depends on the population's fitness (i.e., hard selection). We show that expansion load can severely slow down expansions and limit a species' range, even in the absence of environmental variation. We also study the effect of recombination on the dynamics of a species range and on the evolution of mean fitness on the wave front. If recombination is strong, mean fitness on front approaches an equilibrium value at which the effects of fixed mutations cancel each other out. The equilibrium rate at which new demes are colonized is similar to the rate at which beneficial mutations spread through the core. Without recombination, the dynamics is more complex, and beneficial mutations from the core of the range can invade the front of the expansion, which results in irregular and episodic expansion. Although the rate of adaptation is generally higher in recombining organisms, the mean fitness on the front may be larger in the absence of recombination because high-fitness individuals from the core have a higher chance to invade the front. Our findings have important consequences for the evolutionary dynamics of species ranges as well as on the role and the evolution of recombination during range expansions.
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Affiliation(s)
- Stephan Peischl
- Institute of Ecology and Evolution, University of Berne, 3012 Berne, Switzerland; and Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
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Shimizu KK, Tsuchimatsu T. Evolution of Selfing: Recurrent Patterns in Molecular Adaptation. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2015. [DOI: 10.1146/annurev-ecolsys-112414-054249] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Selfing has evolved in animals, fungi, and plants, and since Darwin's pioneering study, it is considered one of the most frequent evolutionary trends in flowering plants. Generally, the evolution of selfing is characterized by a loss of self-incompatibility, the selfing syndrome, and changes in genome-wide polymorphism patterns. Recent interdisciplinary studies involving molecular functional experiments, genome-wide data, experimental evolution, and evolutionary ecology using Arabidopsis thaliana, Caenorhabditis elegans, and other species show that the evolution of selfing is not merely a degradation of outcrossing traits but a model for studying the recurrent patterns underlying adaptive molecular evolution. For example, in wild Arabidopsis relatives, self-compatibility evolved from mutations in the male specificity gene, S-LOCUS CYSTEINE-RICH PROTEIN/S-LOCUS PROTEIN 11 (SCR/SP11), rather than the female specificity gene, S-LOCUS RECEPTOR KINASE (SRK), supporting the theoretical prediction of sexual asymmetry. Prevalence of dominant self-compatible mutations is consistent with Haldane's sieve, which acts against recessive adaptive mutations. Time estimates based on genome-wide polymorphisms and self-incompatibility genes generally support the recent origin of selfing.
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Affiliation(s)
- Kentaro K. Shimizu
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, CH-8057 Zurich, Switzerland
| | - Takashi Tsuchimatsu
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan
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