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Emel SL, Wang S, Metz RP, Spigler RB. Type and intensity of surrounding human land use, not local environment, shape genetic structure of a native grassland plant. Mol Ecol 2021; 30:639-655. [PMID: 33245827 DOI: 10.1111/mec.15753] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 11/01/2020] [Accepted: 11/13/2020] [Indexed: 12/28/2022]
Abstract
Landscape heterogeneity can shape genetic structure and functional connectivity of populations. When this heterogeneity imposes variable costs of moving across the landscape, populations can be structured according to a pattern of "isolation by resistance" (IBR). At the same time, divergent local environmental filters can limit gene flow, creating an alternative pattern of "isolation by environment" (IBE). Here, we evaluate IBR and IBE in the insect-pollinated, biennial plant Sabatia angularis (L.) Pursh (Gentianaceae) across serpentine grasslands in the fragmented landscape of SE Pennsylvania, USA using ~4500 neutral SNP loci. Specifically, we test the extent to which radical alteration of the landscape matrix by humans has fundamentally altered the cost of movement, imprinting a pattern of IBR dictated by land use type and intensity, and the potential for IBE in relation to a gradient of heavy metal concentrations found in serpentine soil. We reveal a strong signal of IBR and a weak signal of IBE across sites, indicating the greater importance of the landscape matrix in shaping genetic structure of S. angularis populations in the study region. Based on Circuitscape and least cost path approaches, we find that both low- and high-intensity urbanization resist gene flow by orders of magnitude greater than "natural" habitats, although resistance to low-intensity urbanization weakens at larger spatial scales. While cropland presents a substantially lower barrier than urban development, cumulative human land use surrounding populations predicts within-population genetic diversity and inbreeding in S. angularis. Our results emphasize the role of forest buffers and corridors in facilitating gene flow between serpentine grassland patches and averting local extinction of plant populations.
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Affiliation(s)
- Sarah L Emel
- Department of Biology, Temple University, Philadelphia, PA, USA.,Department of Biology, Indiana University of Pennsylvania, Indiana, PA, USA
| | - Shichen Wang
- Genomics and Bioinformatics Service, Texas A&M AgriLife Research, TX, USA
| | - Richard P Metz
- Genomics and Bioinformatics Service, Texas A&M AgriLife Research, TX, USA
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Abdelaziz M, Muñoz-Pajares AJ, Berbel M, García-Muñoz A, Gómez JM, Perfectti F. Asymmetric Reproductive Barriers and Gene Flow Promote the Rise of a Stable Hybrid Zone in the Mediterranean High Mountain. FRONTIERS IN PLANT SCIENCE 2021; 12:687094. [PMID: 34512685 PMCID: PMC8424041 DOI: 10.3389/fpls.2021.687094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 07/15/2021] [Indexed: 05/13/2023]
Abstract
Hybrid zones have the potential to shed light on evolutionary processes driving adaptation and speciation. Secondary contact hybrid zones are particularly powerful natural systems for studying the interaction between divergent genomes to understand the mode and rate at which reproductive isolation accumulates during speciation. We have studied a total of 720 plants belonging to five populations from two Erysimum (Brassicaceae) species presenting a contact zone in the Sierra Nevada mountains (SE Spain). The plants were phenotyped in 2007 and 2017, and most of them were genotyped the first year using 10 microsatellite markers. Plants coming from natural populations were grown in a common garden to evaluate the reproductive barriers between both species by means of controlled crosses. All the plants used for the field and greenhouse study were characterized by measuring traits related to plant size and flower size. We estimated the genetic molecular variances, the genetic differentiation, and the genetic structure by means of the F-statistic and Bayesian inference. We also estimated the amount of recent gene flow between populations. We found a narrow unimodal hybrid zone where the hybrid genotypes appear to have been maintained by significant levels of a unidirectional gene flow coming from parental populations and from weak reproductive isolation between them. Hybrid plants exhibited intermediate or vigorous phenotypes depending on the analyzed trait. The phenotypic differences between the hybrid and the parental plants were highly coherent between the field and controlled cross experiments and through time. The highly coherent results obtained by combining field, experimental, and genetic data demonstrate the existence of a stable and narrow unimodal hybrid zone between Erysimum mediohispanicum and Erysimum nevadense at the high elevation of the Sierra Nevada mountains.
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Affiliation(s)
- Mohamed Abdelaziz
- Departamento de Genética, Facultad de Ciencias, Campus Fuentenueva, Universidad de Granada, Granada, Spain
- *Correspondence: Mohamed Abdelaziz
| | - A. Jesús Muñoz-Pajares
- Departamento de Genética, Facultad de Ciencias, Campus Fuentenueva, Universidad de Granada, Granada, Spain
- Laboratório Associado, Plant Biology, Research Centre in Biodiversity and Genetic Resources, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade Do Porto, Campus Agrário de Vairão, Fornelo e Vairão, Portugal
- Research Unit Modeling Nature, Universidad de Granada, Granada, Spain
| | - Modesto Berbel
- Departamento de Genética, Facultad de Ciencias, Campus Fuentenueva, Universidad de Granada, Granada, Spain
| | - Ana García-Muñoz
- Departamento de Genética, Facultad de Ciencias, Campus Fuentenueva, Universidad de Granada, Granada, Spain
| | - José M. Gómez
- Research Unit Modeling Nature, Universidad de Granada, Granada, Spain
- Departamento de Ecología Funcional y Evolutiva, Estación Experimental de Zonas Áridas, Consejo Superior de Investigaciones Científicas, Almeria, Spain
| | - Francisco Perfectti
- Departamento de Genética, Facultad de Ciencias, Campus Fuentenueva, Universidad de Granada, Granada, Spain
- Research Unit Modeling Nature, Universidad de Granada, Granada, Spain
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Ren G, Mateo RG, Conti E, Salamin N. Population Genetic Structure and Demographic History of Primula fasciculata in Southwest China. FRONTIERS IN PLANT SCIENCE 2020; 11:986. [PMID: 32714358 PMCID: PMC7351516 DOI: 10.3389/fpls.2020.00986] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
Understanding the factors that drive the genetic structure of a species and its responses to past climatic changes is an important first step in modern population management. The response to the last glacial maximum (LGM) has been well studied, however, the effect of previous glaciation periods on plant demographic history is still not well studied. Here we investigated the population structure and demographic history of Primula fasciculata that widely occurs in the Hengduan Mountains and Qinghai-Tibetan Plateau. We obtained genomic data for 234 samples of the species using restriction site-associated DNA (RAD) sequencing and combined approximate Bayesian computation (ABC) and species distribution modeling (SDM) to evaluate the effects of multiple glaciation periods by testing several population divergence models and demographic scenarios. The analyses of population structure showed that P. fasciculata displays a striking population structure with six groups that could be identified genetically. Our ABC modeling suggested that the current groups diverged from ancestral populations located in the eastern Hengduan Mountains after the largest glaciation occurred in the region (~ 0.8-0.5 million years ago), which is consistent with the result of SDMs. Each current group has survived in different glacial refugia during the LGM and experienced expansions and/or bottlenecks since their divergence during or across the following Quaternary glacial cycles. Our study demonstrates the usefulness of population genomics for evaluating the effects of past climatic changes in alpine plant species with shallow population structure.
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Affiliation(s)
- Guangpeng Ren
- State Key Laboratory of Grassland Agro-Ecosystems, School of Life Science, Lanzhou University, Lanzhou, China
- Department of Computational Biology, Biophore, University of Lausanne, Lausanne, Switzerland
| | - Rubén G. Mateo
- Departamento de Biología (Botánica), Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
| | - Elena Conti
- Department of Systematic and Evolutionary Botany and Botanic Garden, University of Zurich, Zurich, Switzerland
| | - Nicolas Salamin
- Department of Computational Biology, Biophore, University of Lausanne, Lausanne, Switzerland
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Combining phylogeography and landscape genetics to infer the evolutionary history of a short-range Mediterranean relict, Salamandra salamandra longirostris. CONSERV GENET 2018. [DOI: 10.1007/s10592-018-1110-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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