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Vieira Lima L, Salino A, Kessler M, Rouhan G, Testo WL, Suzart Argolo C, Consortium G, Elias Almeida T. Phylogenomic evolutionary insights in the fern family Gleicheniaceae. Mol Phylogenet Evol 2023; 184:107782. [PMID: 37044191 DOI: 10.1016/j.ympev.2023.107782] [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: 09/26/2022] [Revised: 03/16/2023] [Accepted: 04/06/2023] [Indexed: 04/14/2023]
Abstract
The pantropical fern family Gleicheniaceae comprises approximately 157 species. Seven genera are currently recognized in the family, although their monophyly is still uncertain due to low sampling in phylogenetic studies. We examined the monophyly of the genera through extended sampling, using the first phylogenomic inference of the family including data from both nuclear and plastid genomes. Seventy-six samples were sequenced (70 Gleicheniaceae species and six outgroups) using high throughput sequencing, including all seven currently recognized genera. Plastid and nuclear data were recovered and assembled; the nuclear data was phased to reduce paralogy as well as hybrid noise in the final recovered topology. Maximum likelihood trees were built for each locus, and a concatenated dataset was built for both datasets. A species tree based on a multispecies coalescent model was generated, and divergence time analyses performed. We here present the first genomic phylogenetic inferences concerning Gleicheniaceae, confirming the monophyly of most genera except Sticherus, which we recovered as paraphyletic. Although most of the extant genera of Gleicheniaceae originated during the Mesozoic, several genera show Neogene and even Quaternary diversifications, and our results suggest that reticulation and polyploidy may have played significant roles during this diversification. However, some genera, such as Rouxopteris and Stromatopteris, appear to represent evolutionary relicts.
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Affiliation(s)
- Lucas Vieira Lima
- Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Botânica, Laboratório de Sistemática Vegetal, Belo Horizonte, Minas Gerais, Brazil.
| | - Alexandre Salino
- Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Botânica, Laboratório de Sistemática Vegetal, Belo Horizonte, Minas Gerais, Brazil.
| | - Michael Kessler
- Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland.
| | - Germinal Rouhan
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, UA, Paris, France.
| | - Weston L Testo
- Department of Science and Education, Negaunee Integrative Research Center, The Field Museum, Chicago, IL, USA.
| | - Caio Suzart Argolo
- Universidade Estadual de Santa Cruz, Departamento de Ciências Biológicas, Centro de Biotecnologia e Genética, Rodovia Ilhéus-Itabuna, km 16, Ilhéus-BA, Brasil.
| | - GoFlag Consortium
- GoFlag is an NSF-funded project (DEB 1541506) based at the University of Florida, Field Museum, and the University of Arizona. Project personnel include (at UF), J. Gordon Burleigh, Emily Sessa, Stuart McDaniel, Christine Davis, Pavlo Antonenko, Sarah Carey, Lorena Endara, Weston Testo; (at Field), Matt von Konrat, Eve Gaus; (at UA): Hong Cui
| | - Thaís Elias Almeida
- Universidade Federal de Pernambuco, Centro de Biociências, Departamento de Botânica, Avenida Professor Morais Rego 1235, CEP 50.670-420, Recife, PE, Brazil.
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Geographic Cline and Genetic Introgression Effects on Seed Morphology Variation and Germination Fitness in Two Closely Related Pine Species in Southeast Asia. FORESTS 2022. [DOI: 10.3390/f13030374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
There is still limited information on how genetic introgression impacts morphological variation and population fitness in long-lived conifer species. Two closely related pine species, Pinus kesiya Royle ex Gordon and Pinus yunnanensis Franch. are widely distributed over Southeast Asia and Yunnan province of China, with a large spatial scale of asymmetric genetic introgression and hybridization, and form a hybrid lineage, P. kesiya var. langbianensis, where their ranges overlap in southeast Yunnan. We compared seed trait variation and germination performance between hybrids and parental species and characterized environmental gradients to investigate the genetic and ecological evolutionary consequences of genetic introgression. We found that seed width (SW) differed significantly among the three pines, and all the seed traits were significantly negatively correlated with latitude and associated with the mean temperatures of the driest and wettest quarters. A higher germination fitness of hybrids was detected at a low temperature, indicating that they had better adaptability to temperature stress than their parental species during the germination process. Our results suggest that environmental factors shape seed phenotypic variation in the pine species and that genetic introgression significantly affects seed germination fitness. Therefore, assisting gene flow in natural forest populations might facilitate their adaptation to climate change.
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Anderson JL, Heard SB, Sweeney J, Pureswaran DS. Mate choice errors may contribute to slow spread of an invasive Eurasian longhorn beetle in North America. NEOBIOTA 2022. [DOI: 10.3897/neobiota.71.72843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Tetropium fuscum (Coleoptera: Cerambycidae) is a Eurasian longhorn beetle and forest pest that first became invasive to Nova Scotia, Canada around 1990. In the time since its introduction, T. fuscum has spread only about 150 km from its point of introduction. In its invasive range, T. fuscum co-exists with its congener Tetropium cinnamopterum. Although they are ecologically similar species, T. fuscum tends to infest healthier trees and has a smaller host range than T. cinnamopterum. If they successfully interbreed, this could lead to hybrid individuals that are more problematic than either parent species. On the other hand, if T. fuscum can make mating errors in the field, but is not producing hybrid offspring, then this waste of mating resources could help explain the slow spread of T. fuscum in North America. We conducted no-choice and choice mating experiments between T. fuscum and T. cinnamopterum males and females and determined that both T. fuscum and T. cinnamopterum males make mate-choice errors with heterospecific females in a laboratory setting. Our results suggest that mating errors may play a role in the slow spread of T. fuscum in North America.
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Šmíd J, Douda J, Krak K, Mandák B. Analyses of Hybrid Viability across a Hybrid Zone between Two Alnus Species Using Microsatellites and cpDNA Markers. Genes (Basel) 2020; 11:E770. [PMID: 32659930 PMCID: PMC7397206 DOI: 10.3390/genes11070770] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/02/2020] [Accepted: 07/06/2020] [Indexed: 01/09/2023] Open
Abstract
Diploid Alnus glutinosa s. str. and autotetraploid A. rohlenae form a narrow hybrid zone in a study area in southern Serbia, which results in triploid hybrid formation. The vast majority of previous studies have been focused on studies of maternal plants, but the offspring resulting from their crossing have not been much studied. Here, we use the variability of microsatellites and chloroplast DNA between these species and their putative hybrids to create an overall picture of the development of the hybrid zone and its predicted type. To elucidate the gene transfer within both species, the origins of individual ploidies and especially the role of triploid hybrids, a germination experiment was carried out linked with a flow cytometry study of the resulting seedlings. The tension zone model seems to offer the most adequate explanation of our observations, with selection against triploid hybrids and the spatial positioning of the hybrid zone. Despite selection against them, the triploid hybrids play an important role in the exchange of genes between the two species and therefore serve as a bridge for introgression. The presence of fertile triploids is essential for enriching the haplotype diversity between these species and for the development of new genetic lineages.
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Affiliation(s)
- Jan Šmíd
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 165 00 Praha-Suchdol, Czech Republic; (J.Š.); (J.D.); (K.K.)
| | - Jan Douda
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 165 00 Praha-Suchdol, Czech Republic; (J.Š.); (J.D.); (K.K.)
| | - Karol Krak
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 165 00 Praha-Suchdol, Czech Republic; (J.Š.); (J.D.); (K.K.)
- Institute of Botany, Czech Academy of Sciences, Zámek 1, CZ-252 43 Průhonice, Czech Republic
| | - Bohumil Mandák
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 165 00 Praha-Suchdol, Czech Republic; (J.Š.); (J.D.); (K.K.)
- Institute of Botany, Czech Academy of Sciences, Zámek 1, CZ-252 43 Průhonice, Czech Republic
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Wong ELY, Nevado B, Osborne OG, Papadopulos AST, Bridle JR, Hiscock SJ, Filatov DA. Strong divergent selection at multiple loci in two closely related species of ragworts adapted to high and low elevations on Mount Etna. Mol Ecol 2019; 29:394-412. [PMID: 31793091 DOI: 10.1111/mec.15319] [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: 06/11/2019] [Revised: 11/28/2019] [Accepted: 11/28/2019] [Indexed: 12/20/2022]
Abstract
Recently diverged species present particularly informative systems for studying speciation and maintenance of genetic divergence in the face of gene flow. We investigated speciation in two closely related Senecio species, S. aethnensis and S. chrysanthemifolius, which grow at high and low elevations, respectively, on Mount Etna, Sicily and form a hybrid zone at intermediate elevations. We used a newly generated genome-wide single nucleotide polymorphism (SNP) dataset from 192 individuals collected over 18 localities along an elevational gradient to reconstruct the likely history of speciation, identify highly differentiated SNPs, and estimate the strength of divergent selection. We found that speciation in this system involved heterogeneous and bidirectional gene flow along the genome, and species experienced marked population size changes in the past. Furthermore, we identified highly-differentiated SNPs between the species, some of which are located in genes potentially involved in ecological differences between species (such as photosynthesis and UV response). We analysed the shape of these SNPs' allele frequency clines along the elevational gradient. These clines show significantly variable coincidence and concordance, indicative of the presence of multifarious selective forces. Selection against hybrids is estimated to be very strong (0.16-0.78) and one of the highest reported in literature. The combination of strong cumulative selection across the genome and previously identified intrinsic incompatibilities probably work together to maintain the genetic and phenotypic differentiation between these species - pointing to the importance of considering both intrinsic and extrinsic factors when studying divergence and speciation.
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Affiliation(s)
- Edgar L Y Wong
- Department of Plant Sciences, University of Oxford, Oxford, UK
| | - Bruno Nevado
- Department of Plant Sciences, University of Oxford, Oxford, UK
| | - Owen G Osborne
- Department of Plant Sciences, University of Oxford, Oxford, UK
| | | | - Jon R Bridle
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Simon J Hiscock
- Department of Plant Sciences, University of Oxford, Oxford, UK
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Lamer JT, Ruebush BC, McClelland MA, Epifanio JM, Sass GG. Body condition ( Wr ) and reproductive potential of bighead and silver carp hybrids: Postzygotic selection in the Mississippi River Basin. Ecol Evol 2019; 9:8978-8986. [PMID: 31462996 PMCID: PMC6706211 DOI: 10.1002/ece3.5423] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 05/28/2019] [Accepted: 06/04/2019] [Indexed: 01/31/2023] Open
Abstract
Invasive bighead (Hypophthalmichthys nobilis) and silver carp (H. molitrix) are reproductively isolated in their native range, but form a bimodal, multigenerational hybrid swarm within the Mississippi River Basin (MRB). Despite observed F1 hybrid superiority in experimental settings, effects of postzygotic selection on bighead and silver carp hybrids have not been tested in a natural system. Individual parent and hybrid genotypes were resolved at 57 species-specific loci and used to evaluate postzygotic selection for body condition (Wr ) and female reproductive potential (presence of spawning stage gonads and gonadosomatic index [GSI]) in the MRB during 2009-2011. Body condition in the Marseilles Reach, Illinois River declined with a decrease in species-specific allele frequency from 1.0 to 0.4 for each species and early generation hybrids (F1, F2, and first-generation backcross) had lower mean Wr than late generation hybrids (2nd+ generation backcrosses) and parentals. Proportions of stage IV and stage V (spawning stage) female gonads differed between bighead and silver carp, but not among parentals and their early and late generation hybrids within the MRB. Mean GSI values did not differ between parentals and hybrids. Because reproductive potential did not differ between hybrids and parentals, our results suggest that early generation hybrids occur in low frequency either as a factor of poor condition (Wr ) and postreproductive survival, infrequent reproductive encounters by parental bighead and silver carp, or selection pressures acting on juvenile or immature life stages. Our results suggest that a combination of genetic and environmental factors may contribute to the postzygotic success of bighead and silver carp hybrids in the Mississippi River Basin.
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Affiliation(s)
- James T. Lamer
- Illinois River Biological Station, Illinois Natural History SurveyPrairie Research InstituteHavanaIllinois
- Department of Natural Resources and Environmental SciencesUniversity of IllinoisChampaignIllinois
| | | | | | | | - Greg G. Sass
- Escanaba Lake Research StationWisconsin Department of Natural ResourcesBoulder JunctionWisconsin
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Mixing It Up: The Role of Hybridization in Forest Management and Conservation under Climate Change. FORESTS 2017. [DOI: 10.3390/f8070237] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Hu J, Zhang J, Chen X, Lv J, Jia H, Zhao S, Lu M. An Empirical Assessment of Transgene Flow from a Bt Transgenic Poplar Plantation. PLoS One 2017; 12:e0170201. [PMID: 28085955 PMCID: PMC5234794 DOI: 10.1371/journal.pone.0170201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 01/01/2017] [Indexed: 11/18/2022] Open
Abstract
To assess the possible impact of transgenic poplar plantations on the ecosystem, we analyzed the frequency and distance of gene flow from a mature male transgenic Populus nigra plantation carrying the Bacillus thuringiensis toxin gene (Bt poplar) and the survival of Bt poplar seeds. The resultant Bt poplar seeds occurred at a frequency of ~0.15% at 0 m to ~0.02% at 500 m from the Bt poplar plantation. The germination of Bt poplar seeds diminished within three weeks in the field (germination rate from 68% to 0%) compared to 48% after three weeks of storage at 4°C. The survival rate of seedlings in the field was 0% without any treatment but increased to 1.7% under the addition of four treatments (cleaning and trimming, watering, weeding, and covering with plastic film to maintain moisture) after being seeded in the field for eight weeks. The results of this study indicate that gene flow originating from the Bt poplar plantation occurred at an extremely low level through pollen or seeds under natural conditions. This study provides first-hand field data on the extent of transgene flow in poplar plantations and offers guidance for the risk assessment of transgenic poplar plantations.
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Affiliation(s)
- Jianjun Hu
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Jin Zhang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | | | - Jinhui Lv
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Huixia Jia
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Shutang Zhao
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Mengzhu Lu
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- * E-mail:
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Gompert Z, Buerkle CA. What, if anything, are hybrids: enduring truths and challenges associated with population structure and gene flow. Evol Appl 2016; 9:909-23. [PMID: 27468308 PMCID: PMC4947152 DOI: 10.1111/eva.12380] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 02/27/2016] [Indexed: 01/17/2023] Open
Abstract
Hybridization is a potent evolutionary process that can affect the origin, maintenance, and loss of biodiversity. Because of its ecological and evolutionary consequences, an understanding of hybridization is important for basic and applied sciences, including conservation biology and agriculture. Herein, we review and discuss ideas that are relevant to the recognition of hybrids and hybridization. We supplement this discussion with simulations. The ideas we present have a long history, particularly in botany, and clarifying them should have practical consequences for managing hybridization and gene flow in plants. One of our primary goals is to illustrate what we can and cannot infer about hybrids and hybridization from molecular data; in other words, we ask when genetic analyses commonly used to study hybridization might mislead us about the history or nature of gene flow and selection. We focus on patterns of variation when hybridization is recent and populations are polymorphic, which are particularly informative for applied issues, such as contemporary hybridization following recent ecological change. We show that hybridization is not a singular process, but instead a collection of related processes with variable outcomes and consequences. Thus, it will often be inappropriate to generalize about the threats or benefits of hybridization from individual studies, and at minimum, it will be important to avoid categorical thinking about what hybridization and hybrids are. We recommend potential sampling and analytical approaches that should help us confront these complexities of hybridization.
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Ávila-Flores IJ, Hernández-Díaz JC, González-Elizondo MS, Prieto-Ruíz JÁ, Wehenkel C. Degree of Hybridization in Seed Stands of Pinus engelmannii Carr. In the Sierra Madre Occidental, Durango, Mexico. PLoS One 2016; 11:e0152651. [PMID: 27064490 PMCID: PMC4827862 DOI: 10.1371/journal.pone.0152651] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 03/17/2016] [Indexed: 11/24/2022] Open
Abstract
Hybridization is an important evolutionary force, because interspecific gene transfer can introduce more new genetic material than is directly generated by mutations. Pinus engelmannii Carr. is one of the nine most common pine species in the pine-oak forest ecoregion in the state of Durango, Mexico. This species is widely harvested for lumber and is also used in reforestation programmes. Interspecific hybrids between P.engelmannii and Pinus arizonica Engelm. have been detected by morphological analysis. The presence of hybrids in P. engelmannii seed stands may affect seed quality and reforestation success. Therefore, the goals of this research were to identify introgressive hybridization between P. engelmannii and other pine species in eight seed stands of this species in Durango, Mexico, and to examine how hybrid proportion is related to mean genetic dissimilarity between trees in these stands, using Amplified Fragment Length Polymorphism (AFLP) markers and morphological traits. Differences in the average current annual increment of putative hybrids and pure trees were also tested for statistical significance. Morphological and genetic analyses of 280 adult trees were carried out. Putative hybrids were found in all the seed stands studied. The hybrids did not differ from the pure trees in vigour or robustness. All stands with putative P. engelmannii hybrids detected by both AFLPs and morphological traits showed the highest average values of the Tanimoto distance, which indicates: i) more heterogeneous genetic material, ii) higher genetic variation and therefore iii) the higher evolutionary potential of these stands, and iv) that the morphological differentiation (hybrid/not hybrid) is strongly associated with the Tanimoto distance per stand. We conclude that natural pairwise hybrids are very common in the studied stands. Both morphological and molecular approaches are necessary to confirm the genetic identity of forest reproductive material.
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Affiliation(s)
- Israel Jaime Ávila-Flores
- Doctorado Institucional en Ciencias Agropecuarias y Forestales, Universidad Juárez del Estado de Durango, Apdo, Postal 741, Zona Centro, Durango, Durango, México, C.P., 34000
| | - José Ciro Hernández-Díaz
- Instituto de Silvicultura e Industria de la Madera, Universidad Juárez del Estado de Durango, Apdo, Postal 741, Zona Centro, Durango, Durango, México, C.P., 34000
| | - Maria Socorro González-Elizondo
- CIIDIR Unidad Durango, Instituto Politécnico Nacional, Sigma 119 Fracc, 20 de Noviembre II, Durango, Durango, México, C.P., 34220
| | - José Ángel Prieto-Ruíz
- Facultad de Ciencias Forestales, Universidad Juárez del Estado de Durango, Blv. Durango y Ave, Papaloapan s/n. Col. Valle del Sur, Durango, Durango, México, C.P., 34120
| | - Christian Wehenkel
- Instituto de Silvicultura e Industria de la Madera, Universidad Juárez del Estado de Durango, Apdo, Postal 741, Zona Centro, Durango, Durango, México, C.P., 34000
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11
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Anthropogenic signature in the incidence and distribution of an emerging pathogen of poplars. Biol Invasions 2016. [DOI: 10.1007/s10530-015-1051-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Floate KD, Godbout J, Lau MK, Isabel N, Whitham TG. Plant-herbivore interactions in a trispecific hybrid swarm of Populus: assessing support for hypotheses of hybrid bridges, evolutionary novelty and genetic similarity. THE NEW PHYTOLOGIST 2016; 209:832-844. [PMID: 26346922 DOI: 10.1111/nph.13622] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 07/28/2015] [Indexed: 06/05/2023]
Abstract
UNLABELLED Natural systems of hybridizing plants are powerful tools with which to assess evolutionary processes between parental species and their associated arthropods. Here we report on these processes in a trispecific hybrid swarm of Populus trees. Using field observations, common garden experiments and genetic markers, we tested the hypothesis that genetic similarities among hosts underlie the distributions of 10 species of gall-forming arthropods and their ability to adapt to new host genotypes. KEY FINDINGS the degree of genetic relatedness among parental species determines whether hybridization is primarily bidirectional or unidirectional; host genotype and genetic similarity strongly affect the distributions of gall-forming species, individually and as a community. These effects were detected observationally in the wild and experimentally in common gardens; correlations between the diversity of host genotypes and their associated arthropods identify hybrid zones as centres of biodiversity and potential species interactions with important ecological and evolutionary consequences. These findings support both hybrid bridge and evolutionary novelty hypotheses. However, the lack of parallel genetic studies on gall-forming arthropods limits our ability to define the host of origin with their subsequent shift to other host species or their evolution on hybrids as their final destination.
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Affiliation(s)
- Kevin D Floate
- Agriculture and Agri-Food Canada, Lethbridge Research Centre, Lethbridge, Alberta, T1J 4B1, Canada
| | - Julie Godbout
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec (Sainte-Foy), QC, G1V 4C7, Canada
| | - Matthew K Lau
- Merriam-Powell Center for Environmental Research and Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Nathalie Isabel
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec (Sainte-Foy), QC, G1V 4C7, Canada
| | - Thomas G Whitham
- Merriam-Powell Center for Environmental Research and Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA
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13
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Ortiz-Barrientos D, Baack EJ. Species integrity in trees. Mol Ecol 2014; 23:4188-91. [PMID: 25155715 DOI: 10.1111/mec.12867] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Revised: 07/14/2014] [Accepted: 07/17/2014] [Indexed: 11/28/2022]
Abstract
From California sequoia, to Australian eucalyptus, to the outstanding diversity of Amazonian forests, trees are fundamental to many processes in ecology and evolution. Trees define the communities that they inhabit, are host to a multiplicity of other organisms and can determine the ecological dynamics of other plants and animals. Trees are also at the heart of major patterns of biodiversity such as the latitudinal gradient of species diversity and thus are important systems for studying the origin of new plant species. Although the role of trees in community assembly and ecological succession is partially understood, the origin of tree diversity remains largely opaque. For instance, the relative importance of differing habitats and phenologies as barriers to hybridization between closely related species is still largely uncharacterized in trees. Consequently, we know very little about the origin of trees species and their integrity. Similarly, studies on the interplay between speciation and tree community assembly are in their infancy and so are studies on how processes like forest maturation modifies the context in which reproductive isolation evolves. In this issue of Molecular Ecology, Lindtke et al. (2014) and Lagache et al. (2014) overcome some traditional difficulties in studying mating systems and sexual isolation in the iconic oaks and poplars, providing novel insights about the integrity of tree species and on how ecology leads to variation in selection on reproductive isolation over time and space.
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14
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Roe AD, MacQuarrie CJK, Gros-Louis MC, Simpson JD, Lamarche J, Beardmore T, Thompson SL, Tanguay P, Isabel N. Fitness dynamics within a poplar hybrid zone: II. Impact of exotic sex on native poplars in an urban jungle. Ecol Evol 2014; 4:1876-89. [PMID: 24963382 PMCID: PMC4063481 DOI: 10.1002/ece3.1028] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 12/20/2013] [Accepted: 12/31/2013] [Indexed: 01/11/2023] Open
Abstract
Trees bearing novel or exotic gene components are poised to contribute to the bioeconomy for a variety of purposes such as bioenergy production, phytoremediation, and carbon sequestration within the forestry sector, but sustainable release of trees with novel traits in large-scale plantations requires the quantification of risks posed to native tree populations. Over the last century, exotic hybrid poplars produced through artificial crosses were planted throughout eastern Canada as ornamentals or windbreaks and these exotics provide a proxy by which to examine the fitness of exotic poplar traits within the natural environment to assess risk of exotic gene escape, establishment, and spread into native gene pools. We assessed postzygotic fitness traits of native and exotic poplars within a naturally regenerated stand in eastern Canada (Quebec City, QC). Pure natives (P. balsamifera and P. deltoides spp. deltoides), native hybrids (P. deltoides × P. balsamifera), and exotic hybrids (trees bearing Populus nigra and P. maximowiczii genetic components) were screened for reproductive biomass, yield, seed germination, and fungal disease susceptibility. Exotic hybrids expressed fitness traits intermediate to pure species and were not significantly different from native hybrids. They formed fully viable seed and backcrossed predominantly with P. balsamifera. These data show that exotic hybrids were not unfit and were capable of establishing and competing within the native stand. Future research will seek to examine the impact of exotic gene regions on associated biotic communities to fully quantify the risk exotic poplars pose to native poplar forests.
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Affiliation(s)
- Amanda D Roe
- Natural Resources Canada, Canadian Forest ServiceQuébec, Québec, Canada
- Natural Resources Canada, Canadian Forest ServiceSault Ste. Marie, Ontario, Canada
| | - Chris JK MacQuarrie
- Natural Resources Canada, Canadian Forest ServiceSault Ste. Marie, Ontario, Canada
| | | | - J Dale Simpson
- Natural Resources Canada, Canadian Forest ServiceFredericton, New-Brunswick, Canada
| | - Josyanne Lamarche
- Natural Resources Canada, Canadian Forest ServiceSault Ste. Marie, Ontario, Canada
| | - Tannis Beardmore
- Natural Resources Canada, Canadian Forest ServiceFredericton, New-Brunswick, Canada
| | - Stacey L Thompson
- Natural Resources Canada, Canadian Forest ServiceQuébec, Québec, Canada
- Umeå University, Department of Ecology and Environmental Science, Umeå Plant Science CentreUmeå, Sweden
| | - Philippe Tanguay
- Natural Resources Canada, Canadian Forest ServiceQuébec, Québec, Canada
| | - Nathalie Isabel
- Natural Resources Canada, Canadian Forest ServiceQuébec, Québec, Canada
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