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Leal JL, Milesi P, Hodková E, Zhou Q, James J, Eklund DM, Pyhäjärvi T, Salojärvi J, Lascoux M. Complex Polyploids: Origins, Genomic Composition, and Role of Introgressed Alleles. Syst Biol 2024; 73:392-418. [PMID: 38613229 PMCID: PMC11282369 DOI: 10.1093/sysbio/syae012] [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: 08/17/2023] [Revised: 12/18/2023] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
Introgression allows polyploid species to acquire new genomic content from diploid progenitors or from other unrelated diploid or polyploid lineages, contributing to genetic diversity and facilitating adaptive allele discovery. In some cases, high levels of introgression elicit the replacement of large numbers of alleles inherited from the polyploid's ancestral species, profoundly reshaping the polyploid's genomic composition. In such complex polyploids, it is often difficult to determine which taxa were the progenitor species and which taxa provided additional introgressive blocks through subsequent hybridization. Here, we use population-level genomic data to reconstruct the phylogenetic history of Betula pubescens (downy birch), a tetraploid species often assumed to be of allopolyploid origin and which is known to hybridize with at least four other birch species. This was achieved by modeling polyploidization and introgression events under the multispecies coalescent and then using an approximate Bayesian computation rejection algorithm to evaluate and compare competing polyploidization models. We provide evidence that B. pubescens is the outcome of an autoploid genome doubling event in the common ancestor of B. pendula and its extant sister species, B. platyphylla, that took place approximately 178,000-188,000 generations ago. Extensive hybridization with B. pendula, B. nana, and B. humilis followed in the aftermath of autopolyploidization, with the relative contribution of each of these species to the B. pubescens genome varying markedly across the species' range. Functional analysis of B. pubescens loci containing alleles introgressed from B. nana identified multiple genes involved in climate adaptation, while loci containing alleles derived from B. humilis revealed several genes involved in the regulation of meiotic stability and pollen viability in plant species.
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Affiliation(s)
- J Luis Leal
- Plant Ecology and Evolution, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
| | - Pascal Milesi
- Plant Ecology and Evolution, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
- Science for Life Laboratory (SciLifeLab), Uppsala University, 75237 Uppsala, Sweden
| | - Eva Hodková
- Plant Ecology and Evolution, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 16521 Prague, Czech Republic
| | - Qiujie Zhou
- Plant Ecology and Evolution, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
| | - Jennifer James
- Plant Ecology and Evolution, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
| | - D Magnus Eklund
- Physiology and Environmental Toxicology, Department of Organismal Biology, Uppsala University, Norbyvägen 18A, 75236 Uppsala, Sweden
| | - Tanja Pyhäjärvi
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, P.O. Box 65 (Viikinkaari 1), 00014 Helsinki, Finland
- Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Jarkko Salojärvi
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, P.O. Box 65 (Viikinkaari 1), 00014 Helsinki, Finland
| | - Martin Lascoux
- Plant Ecology and Evolution, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
- Science for Life Laboratory (SciLifeLab), Uppsala University, 75237 Uppsala, Sweden
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Kauai F, Bafort Q, Mortier F, Van Montagu M, Bonte D, Van de Peer Y. Interspecific transfer of genetic information through polyploid bridges. Proc Natl Acad Sci U S A 2024; 121:e2400018121. [PMID: 38748576 PMCID: PMC11126971 DOI: 10.1073/pnas.2400018121] [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: 01/01/2024] [Accepted: 04/15/2024] [Indexed: 05/27/2024] Open
Abstract
Hybridization blurs species boundaries and leads to intertwined lineages resulting in reticulate evolution. Polyploidy, the outcome of whole genome duplication (WGD), has more recently been implicated in promoting and facilitating hybridization between polyploid species, potentially leading to adaptive introgression. However, because polyploid lineages are usually ephemeral states in the evolutionary history of life it is unclear whether WGD-potentiated hybridization has any appreciable effect on their diploid counterparts. Here, we develop a model of cytotype dynamics within mixed-ploidy populations to demonstrate that polyploidy can in fact serve as a bridge for gene flow between diploid lineages, where introgression is fully or partially hampered by the species barrier. Polyploid bridges emerge in the presence of triploid organisms, which despite critically low levels of fitness, can still allow the transfer of alleles between diploid states of independently evolving mixed-ploidy species. Notably, while marked genetic divergence prevents polyploid-mediated interspecific gene flow, we show that increased recombination rates can offset these evolutionary constraints, allowing a more efficient sorting of alleles at higher-ploidy levels before introgression into diploid gene pools. Additionally, we derive an analytical approximation for the rate of gene flow at the tetraploid level necessary to supersede introgression between diploids with nonzero introgression rates, which is especially relevant for plant species complexes, where interspecific gene flow is ubiquitous. Altogether, our results illustrate the potential impact of polyploid bridges on the (re)distribution of genetic material across ecological communities during evolution, representing a potential force behind reticulation.
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Affiliation(s)
- Felipe Kauai
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent9052, Belgium
- Center for Plant Systems Biology, Bioinformatics and Evolutionary Genomics, VIB, Gent9052, Belgium
- Department of Biology, Terrestrial Ecology Unit, Ghent University, Gent9000, Belgium
| | - Quinten Bafort
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent9052, Belgium
- Center for Plant Systems Biology, Bioinformatics and Evolutionary Genomics, VIB, Gent9052, Belgium
| | - Frederik Mortier
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent9052, Belgium
- Center for Plant Systems Biology, Bioinformatics and Evolutionary Genomics, VIB, Gent9052, Belgium
- Department of Biology, Terrestrial Ecology Unit, Ghent University, Gent9000, Belgium
| | - Marc Van Montagu
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent9052, Belgium
- Center for Plant Systems Biology, Bioinformatics and Evolutionary Genomics, VIB, Gent9052, Belgium
| | - Dries Bonte
- Department of Biology, Terrestrial Ecology Unit, Ghent University, Gent9000, Belgium
| | - Yves Van de Peer
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent9052, Belgium
- Center for Plant Systems Biology, Bioinformatics and Evolutionary Genomics, VIB, Gent9052, Belgium
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria0028, South Africa
- College of Horticulture, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing210095, China
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Lutein Isomers: Preparation, Separation, Structure Elucidation, and Occurrence in 20 Medicinal Plants. Molecules 2023; 28:molecules28031187. [PMID: 36770852 PMCID: PMC9921531 DOI: 10.3390/molecules28031187] [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] [Received: 01/05/2023] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 01/27/2023] Open
Abstract
Lutein and its cis-isomers occur in a lot of plants, including a variety of flowers. In this study, lutein isomers were produced via iodine-catalyzed isomerization, and four cis-isomers (9Z-, 9'Z-, 13Z-, and 13Z') were isolated by means of column chromatography and semipreparative HPLC. The structures of the 9'Z- and 13'Z-isomers were elucidated via NMR measurements. These compounds were used as standards for the HPLC-DAD-MS determination of the carotenoid composition of the flowers of 20 plant species, in which lutein and its geometrical isomers are the main components. The flowers showed great variation in their cis- and trans-lutein content, and also in the presence or absence of other carotenoids, such as violaxanthin, neoxanthin, β-cryptoxanthin, and β-carotene. Some of the investigated flowers were found to be rich sources of lutein without zeaxanthin.
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Brown MR, Becher H, Williams S, Twyford AD. Is there hybridization between diploid and tetraploid Euphrasia in a secondary contact zone? AMERICAN JOURNAL OF BOTANY 2023; 110:e16100. [PMID: 36371731 PMCID: PMC10107515 DOI: 10.1002/ajb2.16100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 10/21/2022] [Accepted: 10/21/2022] [Indexed: 06/16/2023]
Abstract
PREMISE Strong postzygotic reproductive isolating barriers are usually expected to limit the extent of natural hybridization between species with contrasting ploidy. However, genomic sequencing has revealed previously overlooked examples of natural cross-ploidy hybridization in some flowering plant genera, suggesting that the phenomenon may be more common than once thought. We investigated potential cross-ploidy hybridization in British eyebrights (Euphrasia, Orobanchaceae), a group from which 13 putative cross-ploidy hybrid combinations have been reported based on morphology. METHODS We analyzed a contact zone between diploid Euphrasia rostkoviana and tetraploid E. arctica in Wales. We sequenced part of the internal transcribed spacer (ITS) of nuclear ribosomal DNA and used genotyping by sequencing (GBS) to look for evidence of cross-ploidy hybridization and introgression. RESULTS Common variant sites in the ITS region were fixed between diploids and tetraploids, indicating a strong barrier to hybridization. Clustering analyses of 356 single-nucleotide polymorphisms (SNPs) generated using GBS clearly separated samples by ploidy and revealed strong genetic structure (FST = 0.44). However, the FST distribution across all SNPs was bimodal, indicating potential differential selection on loci between diploids and tetraploids. Demographic inference suggested potential gene flow, limited to around one or fewer migrants per generation. CONCLUSIONS Our results suggest that recent cross-ploidy hybridization is rare or absent in a site of secondary contact in Euphrasia. While a strong ploidy barrier prevents hybridization over ecological timescales, such hybrids may form in stable populations over evolutionary timescales, potentially allowing cross-ploidy introgression to take place.
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Affiliation(s)
- Max R. Brown
- Institute of Ecology and EvolutionUniversity of Edinburgh, Ashworth Laboratories, Charlotte Auerbach RoadEdinburghEH9 3FLUK
- Wellcome Sanger InstituteWellcome Genome Campus, HinxtonCambridgeCB10 1SAUK
| | - Hannes Becher
- Institute of Ecology and EvolutionUniversity of Edinburgh, Ashworth Laboratories, Charlotte Auerbach RoadEdinburghEH9 3FLUK
| | - Sebastian Williams
- Institute of Ecology and EvolutionUniversity of Edinburgh, Ashworth Laboratories, Charlotte Auerbach RoadEdinburghEH9 3FLUK
| | - Alex D. Twyford
- Institute of Ecology and EvolutionUniversity of Edinburgh, Ashworth Laboratories, Charlotte Auerbach RoadEdinburghEH9 3FLUK
- Royal Botanic Garden Edinburgh, 20a Inverleith RowEdinburghEH3 5LRUK
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Mandáková T, Zozomová-Lihová J, Kudoh H, Zhao Y, Lysak MA, Marhold K. The story of promiscuous crucifers: origin and genome evolution of an invasive species, Cardamine occulta (Brassicaceae), and its relatives. ANNALS OF BOTANY 2019; 124:209-220. [PMID: 30868165 PMCID: PMC6758578 DOI: 10.1093/aob/mcz019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 01/24/2019] [Indexed: 05/16/2023]
Abstract
BACKGROUND AND AIMS Cardamine occulta (Brassicaceae) is an octoploid weedy species (2n = 8x = 64) originated in Eastern Asia. It has been introduced to other continents including Europe and considered to be an invasive species. Despite its wide distribution, the polyploid origin of C. occulta remained unexplored. The feasibility of comparative chromosome painting (CCP) in crucifers allowed us to elucidate the origin and genome evolution in Cardamine species. We aimed to investigate the genome structure of C. occulta in comparison with its tetraploid (2n = 4x = 32, C. kokaiensis and C. scutata) and octoploid (2n = 8x = 64, C. dentipetala) relatives. METHODS Genomic in situ hybridization (GISH) and large-scale CCP were applied to uncover the parental genomes and chromosome composition of the investigated Cardamine species. KEY RESULTS All investigated species descended from a common ancestral Cardamine genome (n = 8), structurally resembling the Ancestral Crucifer Karyotype (n = 8), but differentiated by a translocation between chromosomes AK6 and AK8. Allotetraploid C. scutata originated by hybridization between two diploid species, C. parviflora and C. amara (2n = 2x = 16). By contrast, C. kokaiensis has an autotetraploid origin from a parental genome related to C. parviflora. Interestingly, octoploid C. occulta probably originated through hybridization between the tetraploids C. scutata and C. kokaiensis. The octoploid genome of C. dentipetala probably originated from C. scutata via autopolyploidization. Except for five species-specific centromere repositionings and one pericentric inversion post-dating the polyploidization events, the parental subgenomes remained stable in the tetra- and octoploids. CONCLUSIONS Comparative genome structure, origin and evolutionary history was reconstructed in C. occulta and related species. For the first time, whole-genome cytogenomic maps were established for octoploid plants. Post-polyploid evolution in Asian Cardamine polyploids has not been associated with descending dysploidy and intergenomic rearrangements. The combination of different parental (sub)genomes adapted to distinct habitats provides an evolutionary advantage to newly formed polyploids by occupying new ecological niches.
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Affiliation(s)
- Terezie Mandáková
- Plant Cytogenomics research group, CEITEC – Central European Institute of Technology, and Faculty of Science, Masaryk University, Kamenice, Czech Republic
| | - Judita Zozomová-Lihová
- Plant Science and Biodiversity Centre, Institute of Botany, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Hiroshi Kudoh
- Center for Ecological Research, Kyoto University, Hirano, Japan
| | - Yunpeng Zhao
- The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou, China
- Laboratory of Systematic and Evolutionary Botany and Biodiversity, Institute of Ecology and Conservation Centre for Gene Resources of Endangered Wildlife, Zhejiang University, Hangzhou, China
| | - Martin A Lysak
- Plant Cytogenomics research group, CEITEC – Central European Institute of Technology, and Faculty of Science, Masaryk University, Kamenice, Czech Republic
| | - Karol Marhold
- Plant Science and Biodiversity Centre, Institute of Botany, Slovak Academy of Sciences, Bratislava, Slovak Republic
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic
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Duration of the conditioning phase affects the results of plant-soil feedback experiments via soil chemical properties. Oecologia 2017; 186:459-470. [DOI: 10.1007/s00442-017-4033-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 12/01/2017] [Indexed: 01/15/2023]
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Evolutionary responses to climate change in a range expanding plant. Oecologia 2017; 184:543-554. [PMID: 28409227 PMCID: PMC5487849 DOI: 10.1007/s00442-017-3864-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 04/04/2017] [Indexed: 12/22/2022]
Abstract
To understand the biological effects of climate change, it is essential to take into account species’ evolutionary responses to their changing environments. Ongoing climate change is resulting in species shifting their geographical distribution ranges poleward. We tested whether a successful range expanding plant has rapidly adapted to the regional conditions in its novel range, and whether adaptation could be driven by herbivores. Furthermore, we investigated if enemy release occurred in the newly colonized areas and whether plant origins differed in herbivore resistance. Plants were cloned and reciprocally transplanted between three experimental sites across the range. Effects of herbivores on plant performance were tested by individually caging plants with either open or closed cages. There was no indication of (regional) adaptation to abiotic conditions. Plants originating from the novel range were always larger than plants from the core distribution at all experimental sites, with or without herbivory. Herbivore damage was highest and not lowest at the experimental sites in the novel range, suggesting no release from enemy impact. Genotypes from the core were more damaged compared to genotypes from newly colonized areas at the most northern site in the novel range, which was dominated by generalist slug herbivory. We also detected subtle shifts in chemical defenses between the plant origins. Genotypes from the novel range had more inducible defenses. Our results suggest that plants that are expanding their range with climate change may evolve increased vigor and altered herbivore resistance in their new range, analogous to invasive plants.
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Rostgaard Nielsen L, Brandes U, Dahl Kjaer E, Fjellheim S. Introduced Scotch broom (Cytisus scoparius) invades the genome of native populations in vulnerable heathland habitats. Mol Ecol 2016; 25:2790-804. [DOI: 10.1111/mec.13666] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 03/21/2016] [Accepted: 04/12/2016] [Indexed: 11/27/2022]
Affiliation(s)
- Lene Rostgaard Nielsen
- Department of Geosciences and Natural Resource Management; University of Copenhagen; Rolighedsvej 23 Frederiksberg C 1958 Denmark
| | - Ursula Brandes
- Department of Plant Sciences; Norwegian University of Life Sciences; Ås NO-1432 Norway
| | - Erik Dahl Kjaer
- Department of Geosciences and Natural Resource Management; University of Copenhagen; Rolighedsvej 23 Frederiksberg C 1958 Denmark
| | - Siri Fjellheim
- Department of Plant Sciences; Norwegian University of Life Sciences; Ås NO-1432 Norway
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Moody ML, Palomino N, Weyl PSR, Coetzee JA, Newman RM, Harms NE, Liu X, Thum RA. Unraveling the biogeographic origins of the Eurasian watermilfoil (Myriophyllum spicatum) invasion in North America. AMERICAN JOURNAL OF BOTANY 2016; 103:709-718. [PMID: 27033316 DOI: 10.3732/ajb.1500476] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 02/17/2016] [Indexed: 06/05/2023]
Abstract
PREMISE OF THE STUDY Using phylogeographic analyses to determine the geographic origins of biological invaders is important for identifying environmental adaptations and genetic composition in their native range as well as biocontrol agents among indigenous herbivores. Eurasian watermilfoil (Myriophyllum spicatum) and its hybrid with northern watermilfoil (M. sibiricum) are found throughout the contiguous United States and southern Canada, forming one of the most economically costly aquatic plant invasions in North America, yet the geographic origin of the invasion remains unknown. The objectives of our study included determining the geographic origin of Eurasian watermilfoil in North America as well as the maternal lineage of the hybrids. METHODS DNA sequence data from a cpDNA intron and the nrDNA ITS region were compiled for accessions from 110 populations of Eurasian watermilfoil and hybrids from North America and the native range (including Europe, Asia, and Africa). Datasets were analyzed using statistical parsimony and Bayesian phylogenetics to assess the geographic origin of the invasion. KEY RESULTS The two Eurasian watermilfoil cpDNA haplotypes in North America are also found from China and Korea, but not elsewhere in the native range. These haplotypes did not overlap and were limited in native geographic range. The ovule parent for hybrids can come from either parental lineage, and multiple haplotypes from both parental species were found. CONCLUSIONS The geographic origin of this prolific aquatic plant invasion of North America is in Asia. This provides critical information to better understand the invasion pathway and inform management into the future.
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Affiliation(s)
- Michael L Moody
- Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, USA
| | - Nayell Palomino
- Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, USA
| | - Philip S R Weyl
- Department of Zoology and Entomology, Rhodes University, Grahamstown, 6140, South Africa
| | - Julie A Coetzee
- Department of Zoology and Entomology, Rhodes University, Grahamstown, 6140, South Africa
| | - Raymond M Newman
- Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, St. Paul, Minnesota, USA
| | - Nathan E Harms
- U.S. Army Engineer Research and Development Center, Environmental Laboratory, 3909 Halls Ferry Rd., Vicksburg, Mississippi, USA
| | - Xing Liu
- Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan, Hubei, China
| | - Ryan A Thum
- Department of Plant Sciences & Plant Pathology, Montana State University, Bozeman, Montana, USA
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Hülber K, Sonnleitner M, Suda J, Krejčíková J, Schönswetter P, Schneeweiss GM, Winkler M. Ecological differentiation, lack of hybrids involving diploids, and asymmetric gene flow between polyploids in narrow contact zones of Senecio carniolicus (syn. Jacobaea carniolica, Asteraceae). Ecol Evol 2015; 5:1224-34. [PMID: 25859328 PMCID: PMC4377266 DOI: 10.1002/ece3.1430] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 01/27/2015] [Accepted: 01/28/2015] [Indexed: 11/09/2022] Open
Abstract
Areas of immediate contact of different cytotypes offer a unique opportunity to study evolutionary dynamics within heteroploid species and to assess isolation mechanisms governing coexistence of cytotypes of different ploidy. The degree of reproductive isolation of cytotypes, that is, the frequency of heteroploid crosses and subsequent formation of viable and (partly) fertile hybrids, plays a crucial role for the long-term integrity of lineages in contact zones. Here, we assessed fine-scale distribution, spatial clustering, and ecological niches as well as patterns of gene flow in parental and hybrid cytotypes in zones of immediate contact of di-, tetra-, and hexaploid Senecio carniolicus (Asteraceae) in the Eastern Alps. Cytotypes were spatially separated also at the investigated microscale; the strongest spatial separation was observed for the fully interfertile tetra- and hexaploids. The three main cytotypes showed highly significant niche differences, which were, however, weaker than across their entire distribution ranges in the Eastern Alps. Individuals with intermediate ploidy levels were found neither in the diploid/tetraploid nor in the diploid/hexaploid contact zones indicating strong reproductive barriers. In contrast, pentaploid individuals were frequent in the tetraploid/hexaploid contact zone, albeit limited to a narrow strip in the immediate contact zone of their parental cytotypes. AFLP fingerprinting data revealed introgressive gene flow mediated by pentaploid hybrids from tetra- to hexaploid individuals, but not vice versa. The ecological niche of pentaploids differed significantly from that of tetraploids but not from hexaploids.
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Affiliation(s)
- Karl Hülber
- Division of Conservation Biology, Vegetation Ecology and Landscape Ecology, Department of Botany and Biodiversity Research, University of ViennaVienna, Austria
- Vienna Institute for Nature Conservation & AnalysesVienna, Austria
| | - Michaela Sonnleitner
- Division of Conservation Biology, Vegetation Ecology and Landscape Ecology, Department of Botany and Biodiversity Research, University of ViennaVienna, Austria
| | - Jan Suda
- Department of Botany, Faculty of Science, Charles University in PraguePrague, Czech Republic
- Institute of Botany, The Czech Academy of SciencesPrůhonice, Czech Republic
| | - Jana Krejčíková
- Department of Botany, Faculty of Science, Charles University in PraguePrague, Czech Republic
| | | | - Gerald M Schneeweiss
- Division of Systematics and Evolutionary Botany, Department of Botany and Biodiversity Research, University of ViennaVienna, Austria
| | - Manuela Winkler
- Division of Systematics and Evolutionary Botany, Department of Botany and Biodiversity Research, University of ViennaVienna, Austria
- GLORIA co-ordination, Center for Global Change and Sustainability, University of Natural Resources and Life Sciences ViennaVienna, Austria
- Institute for Interdisciplinary Mountain Research, Austrian Academy of SciencesInnsbruck, Austria
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Huberty M, Tielbörger K, Harvey JA, Müller C, Macel M. Chemical Defenses (Glucosinolates) of Native and Invasive Populations of the Range Expanding Invasive Plant Rorippa austriaca. J Chem Ecol 2014; 40:363-70. [DOI: 10.1007/s10886-014-0425-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 03/30/2014] [Accepted: 04/01/2014] [Indexed: 10/25/2022]
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12
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Vinogradova YK, Galkina MA, Mayorov SR. Variability of the taxa of the Bidens L. Genera and the problem of hybridization. RUSSIAN JOURNAL OF BIOLOGICAL INVASIONS 2014. [DOI: 10.1134/s2075111714010111] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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Özbek Ö, Görgülü E, Yıldırımlı Ş. Genetic diversity in populations of Isatis glauca Aucher ex Boiss. ssp. from Central Anatolia in Turkey, as revealed by AFLP analysis. BOTANICAL STUDIES 2013; 54:48. [PMID: 28510898 PMCID: PMC5430366 DOI: 10.1186/1999-3110-54-48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 10/14/2013] [Indexed: 06/07/2023]
Abstract
BACKGROUND Isatidae L. is a complex and systematically difficult genus in Brassicaceae. The genus displays great morphological polymorphism, which makes the classification of species and subspecies difficult as it is observed in Isatis glauca Aucher ex Boiss. The aim of this study is characterization of the genetic diversity in subspecies of Isatis glauca Aucher ex Boiss. distributed widely in Central Anatolia, in Turkey by using Amplified Fragment Length Polymorphism (AFLP) technique. RESULTS Eight different Eco RI-Mse I primer combinations produced 805 AFLP loci, 793 (98.5%) of which were polymorphic in 67 accessions representing nine different populations. The data obtained by AFLP was computed with using GDA (Genetic Data Analysis) and STRUCTURE (version 2.3.3) software programs for population genetics. The mean proportion of the polymorphic locus (P), the mean number of alleles (A), the number of unique alleles (U) and the mean value of gene diversity (He) were 0.59, 1.59, 20, and 0.23 respectively. The coancestry coefficient (ϴ) was 0.24. The optimal number of K was identified as seven. The principal component analysis (PCA) explained 85.61% of the total genetic variation. CONCLUSION Isatis glauca ssp. populations showed a high level of genetic diversity, and the AFLP analysis revealed that high polymorphism and differentiated subspecies could be used conveniently for population genetic studies. The principal coordinate analysis (PCoA) based on the dissimilarity matrix, the dendrogram drawn with UPGMA method and STRUCTURE cluster analysis distinguished the accessions successfully. The accessions formed distinctive population structures for populations AA, AB, E, K, and S. Populations AG1 and AG2 seemed to have similar genetic content, in addition, in both populations several hybrid individuals were observed. The accessions did not formed distinctive population structures for both populations AI and ANP. Consequently, Ankara province might be the area, where species Isatis glauca Aucher ex Boiss. originated.
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Affiliation(s)
- Özlem Özbek
- Department of Biology, Faculty of Art and Science, Hitit University, Ulukavak Mah. Çiftlik Çayırı Cd. No: 61, Çorum, Turkey
| | - Elçin Görgülü
- Department of Biology, Faculty of Art and Science, Hitit University, Ulukavak Mah. Çiftlik Çayırı Cd. No: 61, Çorum, Turkey
| | - Şinasi Yıldırımlı
- Department of Biology, Faculty of Science, Hacettepe University, Ankara, Turkey
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Scalone R, Albach DC. Degradation of sexual reproduction in Veronica filiformis after introduction to Europe. BMC Evol Biol 2012. [PMID: 23198765 PMCID: PMC3539859 DOI: 10.1186/1471-2148-12-233] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Baker's law predicts that self-incompatible plant species are generally poor colonizers because their mating system requires a high diversity of genetically differentiated individuals and thus self-compatibility should develop after long-distance dispersal. However, cases like the introduction of the self-incompatible Veronica filiformis (Plantaginaceae) to Europe constitute an often overlooked alternative to this rule. This species was introduced from subalpine areas of the Pontic-Caucasian Mountains and colonized many parts of Central and Western Europe in the last century, apparently without producing seeds. To investigate the consequences of the absence of sexual reproduction in this obligate outcrosser since its introduction, AFLP fingerprints, flower morphology, pollen and ovule production and seed vitality were studied in introduced and native populations. RESULTS Interpopulation crossings of 19 introduced German populations performed in the greenhouse demonstrated that introduced populations are often unable to reproduce sexually. These results were similar to intrapopulation crossings, but this depended on the populations used for crossings. Results from AFLP fingerprinting confirmed a lack of genetic diversity in the area of introduction, which is best explained by the dispersal of clones. Flower morphology revealed the frequent presence of mutations affecting the androecium of the flower and decreasing pollen production in introduced populations. The seeds produced in our experiments were smaller, had a lower germination rate and had lower viability than seeds from the native area. CONCLUSIONS Taken together, our results demonstrate that V. filiformis was able to spread by vegetative means in the absence of sexual reproduction. This came at the cost of an accumulation of phenotypically observable mutations in reproductive characters, i.e. Muller's ratchet.
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Affiliation(s)
- Romain Scalone
- Institut für Spezielle Botanik und Botanischer Garten, Johannes Gutenberg-Universität Mainz, Bentzelweg 9, Mainz 55099, Germany
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Wu W, Zhou RC, Ni GY, Shen H, Ge XJ. Is a new invasive herb emerging? Molecular confirmation and preliminary evaluation of natural hybridization between the invasive Sphagneticola trilobata (Asteraceae) and its native congener S. calendulacea in South China. Biol Invasions 2012. [DOI: 10.1007/s10530-012-0269-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Scremin-Dias E, Lorenz-Lemke AP, Oliveira AKM. The floristic heterogeneity of the Pantanal and the occurrence of species with different adaptive strategies to water stress. BRAZ J BIOL 2011; 71:275-82. [DOI: 10.1590/s1519-69842011000200006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 12/13/2010] [Indexed: 11/22/2022] Open
Abstract
The Pantanal is characterised by a diversity of environments with areas ranging from periodic or permanent heavy flooding to areas with low flood levels, and even environments that never flood. Plant species which inhabit the floodplain are distributed in specific niches, with influence of various phytogeographic domains, including the Seasonal Semi-deciduous Forest, Amazon Rainforest, Cerrado and Chaco, as well rocky remnants, with a wide ecological span in their components. In intensely flooded areas, aquatic macrophytes are widely distributed, with their dynamics closely linked to time, depth and extent of flooding. Although the term "Pantanal" suggests a huge swamp-type wetland, water level variation during a seasonal cycle does not directly reach the root system of many plants. The landscape diversity of the Pantanal wetland is molded by the flood pulse, which interferes with the dynamics of plant communities. Therefore, the retraction and expansion of populations or communities is reflected in important ecological characteristics, considering the variety of morphological, anatomical and ecophysiological features of the species, whose phenotype is the result of a particular genotype. The present study discusses peculiar issues in the adaptation of species distributed in the Pantanal biome and underscores the importance of multidisciplinary approaches to obtain conclusive data on adaptive studies.
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LORENZ-LEMKE ALINEP, TOGNI PAKISAD, MÄDER GERALDO, KRIEDT RAQUELA, STEHMANN JOÃOR, SALZANO FRANCISCOM, BONATTO SANDROL, FREITAS LORETAB. Diversification of plant species in a subtropical region of eastern South American highlands: a phylogeographic perspective on native Petunia (Solanaceae). Mol Ecol 2010; 19:5240-51. [DOI: 10.1111/j.1365-294x.2010.04871.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Wu W, Dai S, Bao H, Zhou R. Hybrid status of Tibouchina urvilleana Cogn. revealed by ITS sequences of nuclear ribosomal DNA. BIOCHEM SYST ECOL 2009. [DOI: 10.1016/j.bse.2009.09.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Mir C, Jarne P, Sarda V, Bonin A, Lumaret R. Contrasting nuclear and cytoplasmic exchanges between phylogenetically distant oak species (Quercus suber L. and Q. ilex L.) in Southern France: inferring crosses and dynamics. PLANT BIOLOGY (STUTTGART, GERMANY) 2009; 11:213-26. [PMID: 19228328 DOI: 10.1111/j.1438-8677.2008.00106.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Gene flow is particularly frequent in the genus Quercus (oaks), especially between closely related species. We focus here on Quercus ilex and the cork-producing Quercus suber, which occasionally hybridize although they are phylogenetically markedly separated. Morphological observations were combined with both allozymic and chloroplastic diagnostic markers to characterize hybridization and introgression and to infer their dynamics in two French regions (French Catalonia and Provence), which are separated by several hundred kilometres. Some hybrids were found in both regions, indicating recent hybridization events. As expected from previous studies, most hybrids resulted from female symbol Q. ilex x male symbol Q. suber crosses, but our data showed that the reciprocal cross is also possible. Partial independence between nuclear and chloroplastic introgression was observed in the two species. Nuclear introgression was limited in both species and both regions, with no preferred direction. In Provence, chloroplastic introgression was very rare in both species. Conversely, all Q. suber individuals from French Catalonia were introgressed by Q. ilex chlorotypes. This might be explained by introgression in the Iberian Peninsula antedating the first occurrence of the two species in French Catalonia. We also observed a new chlorotype that was created locally, and was exchanged between the two species. However, the two species still remain genetically differentiated. The dynamics and complexity of exchanges and the factors determining them (including human management of Q. suber) are discussed.
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Affiliation(s)
- C Mir
- UMR 5175 Centre d'Ecologie Fonctionnelle et Evolutive, Centre National de la Recherche Scientifique, Montpellier, France.
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22
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Introgression between invasive saltcedars (Tamarix chinensis and T. ramosissima) in the USA. Biol Invasions 2008. [DOI: 10.1007/s10530-008-9384-1] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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23
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Abbott RJ, Brennan AC, James JK, Forbes DG, Hegarty MJ, Hiscock SJ. Recent hybrid origin and invasion of the British Isles by a self-incompatible species, Oxford ragwort (Senecio squalidus L., Asteraceae). Biol Invasions 2008. [DOI: 10.1007/s10530-008-9382-3] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Asexual spread versus sexual reproduction and evolution in Japanese Knotweed s.l. sets the stage for the “Battle of the Clones”. Biol Invasions 2008. [DOI: 10.1007/s10530-008-9381-4] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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25
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Zhou R, Gong X, Boufford D, Wu CI, Shi S. Testing a hypothesis of unidirectional hybridization in plants: observations on Sonneratia, Bruguiera and Ligularia. BMC Evol Biol 2008; 8:149. [PMID: 18485207 PMCID: PMC2409324 DOI: 10.1186/1471-2148-8-149] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2007] [Accepted: 05/16/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND When natural hybridization occurs at sites where the hybridizing species differ in abundance, the pollen load delivered to the rare species should be predominantly from the common species. Previous authors have therefore proposed a hypothesis on the direction of hybridization: interspecific hybrids are more likely to have the female parent from the rare species and the male parent from the common species. We wish to test this hypothesis using data of plant hybridizations both from our own experimentation and from the literature. RESULTS By examining the maternally inherited chloroplast DNA of 6 cases of F1 hybridization from four genera of plants, we infer unidirectional hybridization in most cases. In all 5 cases where the relative abundance of the parental species deviates from parity, however, the direction is predominantly in the direction opposite of the prediction based strictly on numerical abundance. CONCLUSION Our results show that the observed direction of hybridization is almost always opposite of the predicted direction based on the relative abundance of the hybridizing species. Several alternative hypotheses, including unidirectional postmating isolation and reinforcement of premating isolation, were discussed.
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Affiliation(s)
- Renchao Zhou
- State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, Sun Yat-Sen University, Guangzhou 510275, PR China
| | - Xun Gong
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, PR China
| | - David Boufford
- Harvard University Herbaria, 22 Divinity Ave, Cambridge, Massachusetts 02138, USA
| | - Chung-I Wu
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois 60637, USA
| | - Suhua Shi
- State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, Sun Yat-Sen University, Guangzhou 510275, PR China
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Milne RI, Abbott RJ. Reproductive isolation among two interfertile Rhododendron species: low frequency of post-F1 hybrid genotypes in alpine hybrid zones. Mol Ecol 2008; 17:1108-21. [PMID: 18261051 DOI: 10.1111/j.1365-294x.2007.03643.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hybrids between the acid-loving species Rhododendron ferrugineum and the basic soil species Rhododendron hirsutum occur on soils of intermediate pH in the European Alps. Material from two hybrid zones approximately 500 m apart, and also nearby populations of each parent species, was surveyed for presence/absence of 31 random amplified polymorphic DNA markers that distinguish parents. Based on morphological assessment, the material comprised 51 putative hybrids, 18 putative R. ferrugineum individuals and 26 putative R. hirsutum plants. RAPD data were analysed using a Bayesian approach implemented by the program newhybrids, and also by principal coordinates analysis. The identity of all R. ferrugineum plants examined was confirmed; however, of the putative R. hirsutum individuals examined, two were certainly and 11 possibly hybrid derivatives. Among all hybrid derivatives examined, about half were designated as F1s or a similar class, otherwise backcrosses to R. hirsutum appeared to be common whereas other hybrid classes were rare and backcrosses to R. ferrugineum possibly absent. Despite this, artificially generated seed of F2 class and backcrosses in each direction showed greater viability than one parent (R. hirsutum). Introgression from R. ferrugineum was also detected in a population that from morphology appeared to contain only R. hirsutum. Hence, the direction of backcrossing might be highly asymmetric within hybrid zones, causing unidirectional gene flow from R. ferrugineum into R. hirsutum. Conversely, the rarity of backcrosses to R. ferrugineum, F2s and later hybrid generations, which might be due to phenology effects and habitat-mediated selection, could play a part in restricting gene flow towards R. ferrugineum.
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Affiliation(s)
- Richard I Milne
- Institute of Molecular Plant Sciences, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JH, UK.
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Hrusa GF, Gaskin JF. The Salsola tragus Complex in California (Chenopodiaceae): Characterization and Status of Salsola australis and the Autochthonous Allopolyploid Salsola ryanii Sp. Nov. ACTA ACUST UNITED AC 2008. [DOI: 10.3120/0024-9637(2008)55[113:tstcic]2.0.co;2] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Introgressive hybridization ofSenecio hercynicusand S.ovatus(Compositae, Senecioneae) along an altitudinal gradient in Harz National Park (Germany). SYST BIODIVERS 2007. [DOI: 10.1017/s1477200007002435] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Introgressive hybridization as the breakdown of postzygotic isolation: a theoretical perspective. Ecol Res 2007. [DOI: 10.1007/s11284-007-0384-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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31
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Lorenz-Lemke AP, Mäder G, Muschner VC, Stehmann JR, Bonatto SL, Salzano FM, Freitas LB. Diversity and natural hybridization in a highly endemic species of Petunia (Solanaceae): a molecular and ecological analysis. Mol Ecol 2007; 15:4487-97. [PMID: 17107478 DOI: 10.1111/j.1365-294x.2006.03100.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Intrinsic reproductive barriers among the species of Petunia are weak and genetic isolation is obtained mainly by geographical separation and ecological diversification. The Serra do Sudeste region in the extreme south of Brazil is one of the centres of diversity of this genus and is characterized by the presence of species with different pollination syndromes. Petunia exserta is known only from four sandstone towers in a restricted area of this region (about 500 km(2)) and is characterized by its differentiated habitat (shelters in the sandstone towers) and by its floral characteristics adapted to ornithophily. In towers where this species is sympatric with the sphingophilous Petunia axillaris, phylogenetically close to P. exserta, we found plants with intermediate floral morphology, suggesting hybridization between them. To test this hypothesis and to better understand its consequences we analysed the sequences of the plastid trnH-psbA, trnS-trnG and psbB-psbH intergenic spacers in 121 individuals sampled all over the P. exserta distribution. The joint analysis of the three markers revealed 13 haplotypes and the network showed two main genetic clades, which probably represent the original gene pool of the two species in the region. In general, individuals of a given population presented the same haplotype, independently of phenotype, corroborating the hybridization hypothesis. Field observations suggest that hummingbirds are responsible for the interspecific gene flow. Analysis of molecular variance revealed high interpopulational diversity among the towers. The low gene flow between populations is possibly related to the autochoric seed dispersion system.
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Affiliation(s)
- Aline P Lorenz-Lemke
- Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Caixa Postal 15053, 91501-970 Porto Alegre, RS, Brazil
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Kapralov MV, Gabrielsen TM, Sarapultsev IE, Brochmann C. Genetic enrichment of the arctic clonal plant Saxifraga cernua at its southern periphery via the alpine sexual Saxifraga sibirica. Mol Ecol 2006; 15:3401-11. [PMID: 16968278 DOI: 10.1111/j.1365-294x.2006.03024.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Isolation of populations at the margins of a species range may lead to decreasing genetic diversity via genetic drift and inbreeding. Hybridization between peripheral populations of two species can, however, counteract genetic impoverishment. The mainly clonal, polyploid plant Saxifraga cernua has a wide arctic distribution but also extends southwards into alpine sites. In the Ural Mountains, its peripheral distribution overlaps with that of its sexually reproducing, diploid relative Saxifraga sibirica, and fertile polyploids of more or less intermediate appearance are found in this overlap zone. We used amplified fragment length polymorphism (AFLP) analysis to address the potential impact of interspecific gene flow on genetic diversity in the peripheral populations. A total of 149 plants from 17 populations along a 1650 km south-north gradient were analysed for 253 markers. The results suggest that three Middle Ural populations containing fertile and morphologically more or less intermediate plants have been affected by hybridization. All of these plants formed a strongly supported (100%) group with S. cernua in a neighbour-joining tree, but their AFLP phenotypes assigned either to S. cernua or to artificial (simulated) F(1) hybrids between S. cernua and S. sibirica in multilocus assignment tests. The three populations were highly diverse with virtually every plant representing a distinct AFLP phenotype, providing additional evidence for formation of later-generation hybrids and/or backcrossing to S. cernua. In contrast, other peripheral populations of S. cernua were typically monoclonal, suggesting that hybridization with S. sibirica can increase genetic diversity in S. cernua at its southern periphery.
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Affiliation(s)
- Maxim V Kapralov
- National Centre for Biosystematics, Natural History Museum, University of Oslo, PO Box 1172 Blindern, NO-0318 Oslo, Norway.
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KOEHLER-SANTOS PATRÍCIA, LORENZ-LEMKE ALINEP, MUSCHNER VALÉRIAC, BONATTO SANDROL, SALZANO FRANCISCOM, FREITAS LORETAB. Molecular genetic variation in Passiflora alata (Passifloraceae), an invasive species in southern Brazil. Biol J Linn Soc Lond 2006. [DOI: 10.1111/j.1095-8312.2006.00647.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Whitney KD, Randell RA, Rieseberg LH. Adaptive introgression of herbivore resistance traits in the weedy sunflower Helianthus annuus. Am Nat 2006; 167:794-807. [PMID: 16649157 DOI: 10.1086/504606] [Citation(s) in RCA: 190] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2005] [Accepted: 02/22/2006] [Indexed: 11/03/2022]
Abstract
The role of hybridization in adaptive evolution is contentious. While many cases of adaptive trait introgression have been proposed, the relevant traits have rarely been identified, resulting in a lack of clear examples of this process. Here, we examine a purported case of adaptive introgression in which the annual sunflower Helianthus annuus annuus has captured alleles from a congener (Helianthus debilis) to form a stabilized hybrid, Helianthus annuus texanus. We tested the hypotheses that herbivore resistance traits have introgressed from H. debilis to H. annuus and have increased adaptation in the latter. In two common gardens, fitness (estimated by seed production) was on average 55% higher in H. a. texanus than in H. a. annuus. For H. a. texanus, three damage traits (of seven tested) differed significantly from the H. a. annuus parent in one or both sites and were shifted in the direction of the more resistant H. debilis. Natural selection favored H. a. annuusxH. debilis BC(1) hybrids (synthesized to mimic the ancestors of H. a. texanus) with H. debilis-like resistance to seed midges Neolasioptera helianthis and to receptacle/seed feeding Lepidoptera at one or both sites. Assuming similar herbivore pressures in the past, these results suggest that introgression of biotic resistance traits was important in the adaptation of H. annuus to central and southern Texas.
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Affiliation(s)
- Kenneth D Whitney
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA.
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Windsor AJ, Schranz ME, Formanová N, Gebauer-Jung S, Bishop JG, Schnabelrauch D, Kroymann J, Mitchell-Olds T. Partial shotgun sequencing of the Boechera stricta genome reveals extensive microsynteny and promoter conservation with Arabidopsis. PLANT PHYSIOLOGY 2006; 140:1169-82. [PMID: 16607030 PMCID: PMC1435815 DOI: 10.1104/pp.105.073981] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Comparative genomics provides insight into the evolutionary dynamics that shape discrete sequences as well as whole genomes. To advance comparative genomics within the Brassicaceae, we have end sequenced 23,136 medium-sized insert clones from Boechera stricta, a wild relative of Arabidopsis (Arabidopsis thaliana). A significant proportion of these sequences, 18,797, are nonredundant and display highly significant similarity (BLASTn e-value < or = 10(-30)) to low copy number Arabidopsis genomic regions, including more than 9,000 annotated coding sequences. We have used this dataset to identify orthologous gene pairs in the two species and to perform a global comparison of DNA regions 5' to annotated coding regions. On average, the 500 nucleotides upstream to coding sequences display 71.4% identity between the two species. In a similar analysis, 61.4% identity was observed between 5' noncoding sequences of Brassica oleracea and Arabidopsis, indicating that regulatory regions are not as diverged among these lineages as previously anticipated. By mapping the B. stricta end sequences onto the Arabidopsis genome, we have identified nearly 2,000 conserved blocks of microsynteny (bracketing 26% of the Arabidopsis genome). A comparison of fully sequenced B. stricta inserts to their homologous Arabidopsis genomic regions indicates that indel polymorphisms >5 kb contribute substantially to the genome size difference observed between the two species. Further, we demonstrate that microsynteny inferred from end-sequence data can be applied to the rapid identification and cloning of genomic regions of interest from nonmodel species. These results suggest that among diploid relatives of Arabidopsis, small- to medium-scale shotgun sequencing approaches can provide rapid and cost-effective benefits to evolutionary and/or functional comparative genomic frameworks.
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Affiliation(s)
- Aaron J Windsor
- Max-Planck-Institut für chemische Okologie, D-07745 Jena, Germany.
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Burgess KS, Morgan M, Deverno L, Husband BC. Asymmetrical introgression between two Morus species (M. alba, M. rubra) that differ in abundance. Mol Ecol 2006; 14:3471-83. [PMID: 16156816 DOI: 10.1111/j.1365-294x.2005.02670.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Asymmetrical introgression is an expected genetic consequence of hybridization when parental taxa differ in abundance; however, evidence for such effects in small populations is scarce. To test this prediction, we estimated the magnitude and direction of hybridization between red mulberry (Morus rubra L.), an endangered species in Canada, and the introduced and more abundant white mulberry (Morus alba L.) using nuclear (randomly amplified polymorphic DNA) and cytoplasmic (chloroplast DNA sequence) markers. Parentage of 184 trees (n = 42 using cpDNA) from four sympatric populations was estimated using a hybrid index and related to six morphological characters and population frequencies of the parental classes. Overall, the frequency of nuclear hybrids was 53.7% (n = 99) and ranged from 43% to 67% among populations. The parental and hybrid taxa differed with respect to all of the morphological traits. Sixty-seven percent of all hybrids contained more nuclear markers from M. alba than M. rubra (hybrid index x = 0.46); among populations, the degree of M. alba bias was correlated with the frequency of M. alba. In addition, the majority of hybrids (68%) contained the chloroplast genome of white mulberry. These results suggest that introgression is bidirectional but asymmetrical and is related, in part, to the relative frequency of parental taxa.
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Affiliation(s)
- K S Burgess
- Department of Botany, University of Guelph, Guelph, ON, Canada, N1G 2W1.
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Bleeker W, Matthies A. Hybrid zones between invasive Rorippa austriaca and native R. sylvestris (Brassicaceae) in Germany: ploidy levels and patterns of fitness in the field. Heredity (Edinb) 2005; 94:664-70. [PMID: 15940276 DOI: 10.1038/sj.hdy.6800687] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Hybrid zones may serve as natural laboratories for evolutionary studies. One common viewpoint is that hybrids may always be less fit than their parents due to genetic discontinuities. An alternative idea is that genotype-environment interactions influence the outcome of natural hybridization. Our comparative study of two different natural hybrid zones between the invasive diploid Rorippa austriaca and the native polyploid R. sylvestris in Germany identified the ploidy level as a major determinant of hybrid fitness. Different ploidy levels and patterns of fitness were detected in different hybrid zones. In one hybrid zone (Mülheim, Ruhr valley) hybrids were pentaploid and showed a relatively high seed set, whereas in the second hybrid zone (Randersacker, Main valley) hybrids were triploid and displayed extremely low fitness values. Analyses of fitness values in different natural hybrid zones between the same two species may lead to very different conclusions about the evolutionary significance of natural hybridization.
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Affiliation(s)
- W Bleeker
- Department of Systematic Botany, University of Osnabrück, Barbarastr. 11, 49076 Osnabrück, Germany.
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Gaskin JF, Zhang DY, Bon MC. Invasion of Lepidium draba (Brassicaceae) in the western United States: distributions and origins of chloroplast DNA haplotypes. Mol Ecol 2005; 14:2331-41. [PMID: 15969718 DOI: 10.1111/j.1365-294x.2005.02589.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Advances in phylogeography are of great value for understanding the population structure and origins of invasive genotypes. Such insights provide constructive information for current or future biological control research efforts. In this study, we investigated a highly variable chloroplast DNA (cpDNA) marker for populations of the weed Lepidium draba (Brassicaceae) in its native Eurasian and invasive US ranges. We sequenced DNA from 684 individuals from Eurasia and the US and found 41 different haplotypes. Our comparative study between the native and invasive ranges showed a 33% reduction in allelic richness (A) and a 7% reduction in haplotype diversity (h) since introduction into the US. Most genetic variation in the native range was observed within geographical regions and populations, not between regions, and this result was similar for the invasive range. Assignment tests indicated the most likely origins of many invasive haplotypes. Some of these occurred in western Europe, supporting an expanded native range that had been proposed for the species. Exact locations were identified for a diverse set of invasive haplotypes which can be used in ongoing host-specificity tests of potential biological control agents.
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Affiliation(s)
- John F Gaskin
- Northern Plains Agricultural Research Laboratory, USDA-ARS, P.O. Box 463, Sidney, MT 59270 USA.
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Facon B, Jarne P, Pointier JP, David P. Hybridization and invasiveness in the freshwater snail Melanoides tuberculata: hybrid vigour is more important than increase in genetic variance. J Evol Biol 2005; 18:524-35. [PMID: 15842482 DOI: 10.1111/j.1420-9101.2005.00887.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Many invasive taxa are hybrids, but how hybridization boosts the invasive process remains poorly known. We address this question in the clonal freshwater snail Melanoides tuberculata from Martinique, using three parental and two hybrid lines. We combine an extensive field survey (1990-2003) and a quantitative genetic experiment to show that hybrid lines have outcompeted their parents in natural habitats, and that this increased invasiveness co-occurred with pronounced shifts in life-history traits, such as growth, fecundity and juvenile size. Given the little time between hybrid creation and sampling, and the moderate standing genetic variance for life-history traits in hybrids, we show that some of the observed trait changes between parents and hybrids were unlikely to arise only by continuous selection. We therefore suggest that a large part of hybrid advantage stems from immediate heterosis upon hybridization.
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Affiliation(s)
- B Facon
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.
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Pinto MA, Rubink WL, Patton JC, Coulson RN, Johnston JS. Africanization in the United States: replacement of feral European honeybees (Apis mellifera L.) by an African hybrid swarm. Genetics 2005; 170:1653-65. [PMID: 15937139 PMCID: PMC1449774 DOI: 10.1534/genetics.104.035030] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The expansion of Africanized honeybees from South America to the southwestern United States in <50 years is considered one of the most spectacular biological invasions yet documented. In the American tropics, it has been shown that during their expansion Africanized honeybees have low levels of introgressed alleles from resident European populations. In the United States, it has been speculated, but not shown, that Africanized honeybees would hybridize extensively with European honeybees. Here we report a continuous 11-year study investigating temporal changes in the genetic structure of a feral population from the southern United States undergoing Africanization. Our microsatellite data showed that (1) the process of Africanization involved both maternal and paternal bidirectional gene flow between European and Africanized honeybees and (2) the panmitic European population was replaced by panmitic mixtures of A. m. scutellata and European genes within 5 years after Africanization. The post-Africanization gene pool (1998-2001) was composed of a diverse array of recombinant classes with a substantial European genetic contribution (mean 25-37%). Therefore, the resulting feral honeybee population of south Texas was best viewed as a hybrid swarm.
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Affiliation(s)
- M Alice Pinto
- Department of Entomology, Texas A&M University, College Station, Texas 77843-2475, USA.
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Kosman E, Leonard KJ. Similarity coefficients for molecular markers in studies of genetic relationships between individuals for haploid, diploid, and polyploid species. Mol Ecol 2005; 14:415-24. [PMID: 15660934 DOI: 10.1111/j.1365-294x.2005.02416.x] [Citation(s) in RCA: 241] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Determining true genetic dissimilarity between individuals is an important and decisive point for clustering and analysing diversity within and among populations, because different dissimilarity indices may yield conflicting outcomes. We show that there are no acceptable universal approaches to assessing the dissimilarity between individuals with molecular markers. Different measures are relevant to dominant and codominant DNA markers depending on the ploidy of organisms. The Dice coefficient is the suitable measure for haploids with codominant markers and it can be applied directly to (0,1)-vectors representing banding profiles of individuals. None of the common measures, Dice, Jaccard, simple mismatch coefficient (or the squared Euclidean distance), is appropriate for diploids with codominant markers. By transforming multiallelic banding patterns at each locus into the corresponding homozygous or heterozygous states, a new measure of dissimilarity within locus was developed and expanded to assess dissimilarity between multilocus states of two individuals by averaging across all codominant loci tested. There is no rigorous well-founded solution in the case of dominant markers. The simple mismatch coefficient is the most suitable measure of dissimilarity between banding patterns of closely related haploid forms. For distantly related haploid individuals, the Jaccard dissimilarity is recommended. In general, no suitable method for measuring genetic dissimilarity between diploids with dominant markers can be proposed. Banding patterns of diploids with dominant markers and polyploids with codominant markers represent individuals' phenotypes rather than genotypes. All dissimilarity measures proposed and developed herein are metrics.
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Affiliation(s)
- E Kosman
- Institute for Cereal Crops Improvement (ICCI), The George S. Wise Faculty for Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
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