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Yang LH, Shi XZ, Wen F, Kang M. Phylogenomics reveals widespread hybridization and polyploidization in Henckelia (Gesneriaceae). ANNALS OF BOTANY 2023; 131:953-966. [PMID: 37177810 PMCID: PMC10332401 DOI: 10.1093/aob/mcad047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 05/12/2023] [Indexed: 05/15/2023]
Abstract
BACKGROUND AND AIMS Hybridization has long been recognized as an important process for plant evolution and is often accompanied by polyploidization, another prominent force in generating biodiversity. Despite its pivotal importance in evolution, the actual prevalence and distribution of hybridization across the tree of life remain unclear. METHODS We used whole-genome shotgun (WGS) sequencing and cytological data to investigate the evolutionary history of Henckelia, a large genus in the family Gesneriaceae with a high frequency of suspected hybridization and polyploidization events. We generated WGS sequencing data at about 10× coverage for 26 Chinese Henckelia species plus one Sri Lankan species. To untangle the hybridization history, we separately extracted whole plastomes and thousands of single-copy nuclear genes from the sequencing data, and reconstructed phylogenies based on both nuclear and plastid data. We also explored sources of both genealogical and cytonuclear conflicts and identified signals of hybridization and introgression within our phylogenomic dataset using several statistical methods. Additionally, to test the polyploidization history, we evaluated chromosome counts for 45 populations of the 27 Henckelia species studied. KEY RESULTS We obtained well-supported phylogenetic relationships using both concatenation- and coalescent-based methods. However, the nuclear phylogenies were highly inconsistent with the plastid phylogeny, and we observed intensive discordance among nuclear gene trees. Further analyses suggested that both incomplete lineage sorting and gene flow contributed to the observed cytonuclear and genealogical discordance. Our analyses of introgression and phylogenetic networks revealed a complex history of hybridization within the genus Henckelia. In addition, based on chromosome counts for 27 Henckelia species, we found independent polyploidization events occurred within Henckelia after different hybridization events. CONCLUSIONS Our findings demonstrated that hybridization and polyploidization are common in Henckelia. Furthermore, our results revealed that H. oblongifolia is not a member of the redefined Henckelia and they suggested several other taxonomic treatments in this genus.
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Affiliation(s)
- Li-Hua Yang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
- South China National Botanical Garden, Guangzhou 510650, China
| | - Xi-Zuo Shi
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fang Wen
- Gesneriad Conservation Center of China, Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences, Guilin 541006, China
| | - Ming Kang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
- South China National Botanical Garden, Guangzhou 510650, China
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Wagner F, Ott T, Zimmer C, Reichhart V, Vogt R, Oberprieler C. 'At the crossroads towards polyploidy': genomic divergence and extent of homoploid hybridization are drivers for the formation of the ox-eye daisy polyploid complex (Leucanthemum, Compositae-Anthemideae). THE NEW PHYTOLOGIST 2019; 223:2039-2053. [PMID: 30851196 DOI: 10.1111/nph.15784] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 03/06/2019] [Indexed: 05/23/2023]
Abstract
Polyploidy plays a paramount role in phytodiversity, but the causes of this evolutionary pathway require further study. Here, we use phylogenetic methods to examine possible polyploidy-promoting factors by comparing diploid representatives of the comprehensive European polyploid complex Leucanthemum with members of its strictly diploid North African counterpart Rhodanthemum. We investigate genetic divergence and gene flow among all diploid lineages of both genera to evaluate the role of genomic differentiation and hybridization for polyploid speciation. To test whether hybridization in Leucanthemum has been triggered by the geological conditions during its diversification, we additionally generate a time-calibrated phylogeny of 46 species of the subtribe Leucantheminae. Leucanthemum shows a significantly higher genetic divergence and hybridization signal among diploid lineages compared with Rhodanthemum, in spite of a similar crown age and diversification pattern during the Quaternary. Our study demonstrates the importance of genetic differentiation among diploid progenitors and their concurrent affinity for natural hybridization for the formation of a polyploid complex. Furthermore, the role of climate-induced range overlaps on hybridization and polyploid speciation during the Quaternary is discussed.
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Affiliation(s)
- Florian Wagner
- Evolutionary and Systematic Botany Group, Institute of Plant Sciences, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
| | - Tankred Ott
- Evolutionary and Systematic Botany Group, Institute of Plant Sciences, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
| | - Claudia Zimmer
- Evolutionary and Systematic Botany Group, Institute of Plant Sciences, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
| | - Verena Reichhart
- Evolutionary and Systematic Botany Group, Institute of Plant Sciences, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
| | - Robert Vogt
- Botanic Garden & Botanical Museum Berlin-Dahlem, Freie Universität Berlin, Königin-Luise-Str. 6-8, D-14191, Berlin, Germany
| | - Christoph Oberprieler
- Evolutionary and Systematic Botany Group, Institute of Plant Sciences, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
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Ramírez-Aguirre E, Martén-Rodríguez S, Quesada-Avila G, Quesada M, Martínez-Díaz Y, Oyama K, Espinosa-García FJ. Reproductive isolation among three sympatric Achimenes species: pre- and post-pollination components. AMERICAN JOURNAL OF BOTANY 2019; 106:1021-1031. [PMID: 31299090 DOI: 10.1002/ajb2.1324] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 05/06/2019] [Indexed: 06/10/2023]
Abstract
PREMISE Closely related species occurring in sympatry may experience the negative consequences of interspecific pollen transfer if reproductive isolation (RI) barriers are not in place. We evaluated the importance of pre- and post-pollination RI barriers in three sympatric species of Achimenes (Gesneriaceae), including ecogeographic, phenological, floral isolation, self-pollination, and hybrid viability (fruit and seed set). METHODS We recorded geographic distribution throughout species ranges and assessed flowering phenology and pollinator visitation at one site in central Mexico. In the greenhouse, we measured floral traits involved in RI and quantified fruit and seed set for from self, intraspecific, and interspecific crosses. RESULTS Ecogeographic barriers were important in RI, but under sympatry, phenological and floral barriers contributed more to total RI. Phenological RI varied between species and years, while floral RI was 100% effective at preventing interspecific visitation. Species showed differences in floral morphology, color, and scents associated with specialized pollination systems (A. antirrhina-hummingbirds, A. flava-bees, A. patens-butterflies); heterospecific visitation events were restricted to rare secondary pollinators. Hybrid crosses consistently yielded progeny in lower numbers than intraspecific crosses. CONCLUSIONS This study indicated that neither autogamy nor early post-pollination barriers prevent interspecific pollen flow between Achimenes species. However, floral isolation, acting through a combination of attraction and reward traits, consistently ensures specificity of the pollination system. These results suggest that selection on floral traits to reduce the costs of hybrid progeny production may have played a role in evolution or maintenance of specialized pollination systems in Achimenes.
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Affiliation(s)
- Erandi Ramírez-Aguirre
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores (ENES), Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, C.P. 58190, México
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México. Unidad de Posgrado, Coordinación del Posgrado en Ciencias Biológicas. Edificio D, 1º Piso. Circuito de Posgrados, Ciudad Universitaria Del., Coyoacán, C. P. 04510, México D.F
| | - Silvana Martén-Rodríguez
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores (ENES), Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, C.P. 58190, México
| | - Gabriela Quesada-Avila
- Universidad Nacional de Costa Rica, Heredia, Costa Rica. Avenida 1, Calle 9. Apartado Postal, 86-3000
| | - Mauricio Quesada
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores (ENES), Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, C.P. 58190, México
- Instituto de Investigaciones en Ecosistemas, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro 8701, Morelia, Michoacán, C.P. 58190, México
| | - Yesenia Martínez-Díaz
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores (ENES), Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, C.P. 58190, México
| | - Ken Oyama
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores (ENES), Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, C.P. 58190, México
| | - Francisco J Espinosa-García
- Instituto de Investigaciones en Ecosistemas, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro 8701, Morelia, Michoacán, C.P. 58190, México
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Nicola MV, Johnson LA, Pozner R. Unraveling patterns and processes of diversification in the South Andean-Patagonian Nassauvia subgenus Strongyloma (Asteraceae, Nassauvieae). Mol Phylogenet Evol 2019; 136:164-182. [PMID: 30858079 DOI: 10.1016/j.ympev.2019.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 02/11/2019] [Accepted: 03/07/2019] [Indexed: 12/26/2022]
Abstract
Congruence among different sources of data is highly desirable in phylogenetic analyses. However, plastid and nuclear DNA may record different evolutionary processes such that incongruence among results from these sources can help unravel complex evolutionary histories. That is the case of Nassauvia subgenus Strongyloma (Asteraceae), a taxon with five putative species distributed in the southern Andes and Patagonian steppe. Morphometric and phylogeographic information cast doubt on the integrity of its species, and previous molecular data even questioned the monophyly of the subgenus. We tested those questions using plastid and nuclear DNA sequences by the application of different methods such as phylogenetic trees, networks, a test of genealogical sorting, an analysis of population structure, calibration of the trees, and hybridization test, assembling non-synchronous incongruent results at subgenus and species levels in a single reconstruction. The integration of our molecular analyses and previous taxonomic, morphological, and molecular studies support subgenus Strongyloma as a monophyletic group. However, the topology of the nuclear trees and the evidence of polyploids within subgenus Nassauvia, suggest a hypothetical origin and initial radiation of Nassauvia related to an ancient hybridization event that occurred around 17-6.3 Myr ago near the Andes in west-central Patagonia. Plastid data suggest a recent diversification within subgenus Strongyloma, at most 9.8 Myr ago, towards the Patagonian steppe east of the Andes. These processes cause phylogenies to deviate from the species tree since each putative species lack exclusive ancestry. The non-monophyly of its species using both plastid and nuclear data is caused mainly by incomplete lineage sorting occurred since the Miocene. The final uplift of the Andes and Pliocene-Pleistocene glacial-interglacial and its consequences on the landscape and climate structured the genetic composition of this group of plants in the Patagonian steppe. The molecular data presented here agree with previous morphological studies, in that the five putative species typically accepted in this subgenus are not independent taxa. This study emphasizes that adding more than one sequence per species, not combining data with dissimilar inheritance patterns without first performed incongruence tests, exploring data through different methodologies, considering the timing of events, and searching for the causes of poorly resolved and/or incongruent phylogenies help to reveal complex biological underlying processes, which might otherwise remain hidden.
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Affiliation(s)
- Marcela V Nicola
- Instituto de Botánica Darwinion (CONICET-ANCEFN), Labardén 200, C.C. 22, B1642HYD, San Isidro, Provincia de Buenos Aires, Argentina.
| | - Leigh A Johnson
- Department of Biology and Bean Life Science Museum, 4102 LSB, Brigham Young University, Provo, UT 84602, USA
| | - Raúl Pozner
- Instituto de Botánica Darwinion (CONICET-ANCEFN), Labardén 200, C.C. 22, B1642HYD, San Isidro, Provincia de Buenos Aires, Argentina
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Characterization and Comparative Analysis of the Complete Chloroplast Genome of the Critically Endangered Species Streptocarpus teitensis (Gesneriaceae). BIOMED RESEARCH INTERNATIONAL 2018; 2018:1507847. [PMID: 29770326 PMCID: PMC5889905 DOI: 10.1155/2018/1507847] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/27/2017] [Accepted: 01/28/2018] [Indexed: 11/28/2022]
Abstract
Streptocarpus teitensis (Gesneriaceae) is an endemic species listed as critically endangered in the International Union for Conservation of Nature (IUCN) red list of threatened species. However, the sequence and genome information of this species remains to be limited. In this article, we present the complete chloroplast genome structure of Streptocarpus teitensis and its evolution inferred through comparative studies with other related species. S. teitensis displayed a chloroplast genome size of 153,207 bp, sheltering a pair of inverted repeats (IR) of 25,402 bp each split by small and large single-copy (SSC and LSC) regions of 18,300 and 84,103 bp, respectively. The chloroplast genome was observed to contain 116 unique genes, of which 80 are protein-coding, 32 are transfer RNAs, and four are ribosomal RNAs. In addition, a total of 196 SSR markers were detected in the chloroplast genome of Streptocarpus teitensis with mononucleotides (57.1%) being the majority, followed by trinucleotides (33.2%) and dinucleotides and tetranucleotides (both 4.1%), and pentanucleotides being the least (1.5%). Genome alignment indicated that this genome was comparable to other sequenced members of order Lamiales. The phylogenetic analysis suggested that Streptocarpus teitensis is closely related to Lysionotus pauciflorus and Dorcoceras hygrometricum.
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Smith JF, Clark JL, Amaya-Márquez M, Marín-Gómez OH. Resolving incongruence: Species of hybrid origin in Columnea (Gesneriaceae). Mol Phylogenet Evol 2017; 106:228-240. [DOI: 10.1016/j.ympev.2016.10.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 09/30/2016] [Accepted: 10/03/2016] [Indexed: 01/19/2023]
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7
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Oberprieler C, Wagner F, Tomasello S, Konowalik K. A permutation approach for inferring species networks from gene trees in polyploid complexes by minimising deep coalescences. Methods Ecol Evol 2016. [DOI: 10.1111/2041-210x.12694] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Christoph Oberprieler
- Evolutionary and Systematic Botany Group Institute of Plant Sciences University of Regensburg Universitätsstr. 31 D‐93053 Regensburg Germany
| | - Florian Wagner
- Evolutionary and Systematic Botany Group Institute of Plant Sciences University of Regensburg Universitätsstr. 31 D‐93053 Regensburg Germany
| | - Salvatore Tomasello
- Evolutionary and Systematic Botany Group Institute of Plant Sciences University of Regensburg Universitätsstr. 31 D‐93053 Regensburg Germany
- Systematic Botany and Mycology Department of Biology Ludwig‐Maximilians‐University Munich (LMU) Menzingerstr. 67 D‐80638 Munich Germany
| | - Kamil Konowalik
- Evolutionary and Systematic Botany Group Institute of Plant Sciences University of Regensburg Universitätsstr. 31 D‐93053 Regensburg Germany
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Meeus S, Janssens S, Helsen K, Jacquemyn H. Evolutionary trends in the distylous genus Pulmonaria (Boraginaceae): Evidence of ancient hybridization and current interspecific gene flow. Mol Phylogenet Evol 2016; 98:63-73. [DOI: 10.1016/j.ympev.2015.11.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 11/28/2015] [Accepted: 11/30/2015] [Indexed: 10/22/2022]
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Roalson EH, Roberts WR. Distinct Processes Drive Diversification in Different Clades of Gesneriaceae. Syst Biol 2016; 65:662-84. [DOI: 10.1093/sysbio/syw012] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 01/02/2016] [Indexed: 01/19/2023] Open
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Gruenstaeudl M. WARACS: Wrappers to Automate the Reconstruction of Ancestral Character States. APPLICATIONS IN PLANT SCIENCES 2016; 4:apps.1500120. [PMID: 26949580 PMCID: PMC4760752 DOI: 10.3732/apps.1500120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Accepted: 12/20/2015] [Indexed: 06/05/2023]
Abstract
PREMISE OF THE STUDY Reconstructions of ancestral character states are among the most widely used analyses for evaluating the morphological, cytological, or ecological evolution of an organismic lineage. The software application Mesquite remains the most popular application for such reconstructions among plant scientists, even though its support for automating complex analyses is limited. A software tool is needed that automates the reconstruction and visualization of ancestral character states with Mesquite and similar applications. METHODS AND RESULTS A set of command line-based Python scripts was developed that (a) communicates standardized input to and output from the software applications Mesquite, BayesTraits, and TreeGraph2; (b) automates the process of ancestral character state reconstruction; and (c) facilitates the visualization of reconstruction results. CONCLUSIONS WARACS provides a simple tool that streamlines the reconstruction and visualization of ancestral character states over a wide array of parameters, including tree distribution, character state, and optimality criterion.
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Affiliation(s)
- Michael Gruenstaeudl
- Institut für Biologie-Botanik, Dahlem Centre of Plant Sciences, Freie Universität Berlin, Altensteinstraße 6, 14195 Berlin, Germany
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11
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Konowalik K, Wagner F, Tomasello S, Vogt R, Oberprieler C. Detecting reticulate relationships among diploid Leucanthemum Mill. (Compositae, Anthemideae) taxa using multilocus species tree reconstruction methods and AFLP fingerprinting. Mol Phylogenet Evol 2015; 92:308-28. [DOI: 10.1016/j.ympev.2015.06.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 05/29/2015] [Accepted: 06/02/2015] [Indexed: 12/23/2022]
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Mugrabi de Kuppler AL, Fagúndez J, Bellstedt DU, Oliver EGH, Léon J, Pirie MD. Testing reticulate versus coalescent origins of Erica lusitanica using a species phylogeny of the northern heathers (Ericeae, Ericaceae). Mol Phylogenet Evol 2015; 88:121-31. [PMID: 25888972 DOI: 10.1016/j.ympev.2015.04.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 04/02/2015] [Accepted: 04/06/2015] [Indexed: 10/23/2022]
Abstract
Whilst most of the immense species richness of heathers (Calluna, Daboecia and Erica: Ericeae; Ericaceae) is endemic to Africa, particularly the Cape Floristic Region, the oldest lineages are found in the Northern Hemisphere. We present phylogenetic hypotheses for the major clades of Ericeae represented by multiple accessions of all northern Erica species and placeholder taxa for the large nested African/Madagascan clade. We identified consistent, strongly supported conflict between gene trees inferred from ITS and chloroplast DNA sequences with regard to the position of Erica lusitanica. We used coalescent simulations to test whether this conflict could be explained by coalescent stochasticity, as opposed to reticulation (e.g. hybridisation), given estimates of clade ages, generation time and effective population sizes (Ne). A standard approach, comparing overall differences between real and simulated trees, could not clearly reject coalescence. However, additional simulations showed that at the (higher) Ne necessary to explain conflict in E. lusitanica, further topological conflict would also be expected. Ancient hybridisation between ancestors of northern species is therefore a plausible scenario to explain the origin of E. lusitanica, and its morphological similarities to E. arborea. Assuming either process influences the results of species tree and further evolutionary inference. The coalescence scenario is equivocal with regard the standing hypothesis of stepping stone dispersal of Erica from Europe into Africa; whereas reticulate evolution in E. lusitanica would imply that the colonisation of Tropical East Africa by E. arborea instead occurred independently of dispersals within the rest of the African/Madagascan clade.
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Affiliation(s)
- A L Mugrabi de Kuppler
- INRES Pflanzenzüchtung, Rheinische Friedrich-Wilhelms-Universität Bonn, Katzenburgweg 5, 53115 Bonn, Germany
| | - J Fagúndez
- Department of Plant and Animal Biology and Ecology, University of A Coruña, Faculty of Science, 15001 A Coruña, Spain
| | - D U Bellstedt
- Department of Biochemistry, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa
| | - E G H Oliver
- Department of Botany and Zoology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa
| | - J Léon
- INRES Pflanzenzüchtung, Rheinische Friedrich-Wilhelms-Universität Bonn, Katzenburgweg 5, 53115 Bonn, Germany
| | - M D Pirie
- Department of Biochemistry, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa; Institut für Spezielle Botanik und Botanischer Garten, Johannes Gutenberg-Universität, Anselm-Franz-von-Bentzelweg 9a, 55099 Mainz, Germany.
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Pimentel M, Sahuquillo E, Torrecilla Z, Popp M, Catalán P, Brochmann C. Hybridization and long-distance colonization at different time scales: towards resolution of long-term controversies in the sweet vernal grasses (Anthoxanthum). ANNALS OF BOTANY 2013; 112:1015-30. [PMID: 23912698 PMCID: PMC3783235 DOI: 10.1093/aob/mct170] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 06/10/2013] [Indexed: 05/24/2023]
Abstract
BACKGROUND AND AIMS Repeated hybridization and/or polyploidization confound classification and phylogenetic inference, and multiple colonizations at different time scales complicate biogeographical reconstructions. This study investigates whether such processes can explain long-term controversies in Anthoxanthum, and in particular its debated relationship to the genus Hierochloë, the evolution of its conspicuously diverse floral morphology, and the origins of its strikingly disjunct occurrences. A hypothesis for recurrent polyploid formation is proposed. METHODS Three plastid (trnH-psbA, trnT-L and trnL-F) and two nuclear (ITS, ETS) DNA regions were sequenced in 57 accessions of 17 taxa (including 161 ETS clones) and Bayesian phylogenetic analyses were conducted. Divergence times were inferred in *BEAST using a strict molecular clock. KEY RESULTS Anthoxanthum was inferred as monophyletic and sister to one species of Hierochloë based on the plastid data, whereas the nuclear data suggested that one section (Anthoxanthum section Anthoxanthum) is sister to a clade including the other section (Anthoxanthum section Ataxia) as sister to the genus Hierochloë. This could explain the variation in floral morphology; the aberrant characters in Ataxia seem to result from a Miocene hybridization event between one lineage with one fertile and two sterile florets (the Anthoxanthum lineage) and one which probably had three fertile florets as in extant Hierochloë. The distinct diploid A. gracile lineage originated in the Miocene; all other speciation events, many of them involving polyploidy, were dated to the Late Pliocene to Late Pleistocene. Africa was apparently colonized twice in the Late Pliocene (from the north to afro-alpine eastern Africa, and from south-east Asia to southern Africa), whereas Macaronesia was colonized much later (Late Pleistocene) by a diploid Mediterranean lineage. The widespread European tetraploid A. odoratum originated at least twice. CONCLUSIONS Many of the controversies in Anthoxanthum can be explained by recurring hybridization and/or polyploidization on time scales ranging from the Miocene to the Late Pleistocene. All but one of the extant species shared most recent common ancestors in the Late Pliocene to the Late Pleistocene. The disjunct occurrences in Africa originated in the Late Pliocene via independent immigrations, whereas Macaronesia was colonized in the Late Pleistocene.
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Affiliation(s)
- Manuel Pimentel
- Grupo de Investigación en Bioloxía Evolutiva (GIBE), Facultade de Ciencias, Universidade da Coruña, Campus da Zapateira sn. 15071 A Coruña, Spain
- National Centre for Biosystematics, Natural History Museum, University of Oslo, PO Box 1172 Blindern, NO-0318 Oslo, Norway
| | - Elvira Sahuquillo
- Grupo de Investigación en Bioloxía Evolutiva (GIBE), Facultade de Ciencias, Universidade da Coruña, Campus da Zapateira sn. 15071 A Coruña, Spain
| | - Zeltia Torrecilla
- Grupo de Investigación en Bioloxía Evolutiva (GIBE), Facultade de Ciencias, Universidade da Coruña, Campus da Zapateira sn. 15071 A Coruña, Spain
| | - Magnus Popp
- National Centre for Biosystematics, Natural History Museum, University of Oslo, PO Box 1172 Blindern, NO-0318 Oslo, Norway
| | - Pilar Catalán
- Escuela Politécnica Superior de Huesca, Universidad de Zaragoza, Carretera de Cuarte km 1, 22071 Huesca, Spain
| | - Christian Brochmann
- National Centre for Biosystematics, Natural History Museum, University of Oslo, PO Box 1172 Blindern, NO-0318 Oslo, Norway
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Dillenberger MS, Kadereit JW. The phylogeny of the European high mountain genus Adenostyles (Asteraceae-Senecioneae) reveals that edaphic shifts coincide with dispersal events. AMERICAN JOURNAL OF BOTANY 2013; 100:1171-1183. [PMID: 23709635 DOI: 10.3732/ajb.1300060] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
PREMISE OF THE STUDY Heterogeneity of edaphic conditions plays a large role in driving the diversification of many plant groups. In the Alps and other European high mountains, many closely related calcicole and calcifuge plant taxa exist. To better understand patterns and processes of edaphic differentiation, the phylogeny of the edaphically variable genus Adenostyles was studied. The genus contains three species, of which A. alpina has five subspecies. Each species and subspecies is largely confined to either calcareous or noncalcareous substrates. • METHODS We analyzed the phylogeny of Adenostyles using DNA sequences of nrITS, nrETS, nuclear chalcone synthase, and three plastid markers (rpl32-trnL, psbA-trnH, and ndhF-rpl32) from 45 in-group and five out-group samples. The phylogeny was used to reconstruct ancestral edaphic associations and distribution areas. • KEY RESULTS Within Adenostyles alpina, the shifts of edaphic association from calcicole to calcifuge in subsp. briquetii (Corsica) and in a clade of subsp. macrocephala (southernmost Italy) plus subsp. pyrenaica (Pyrenees) coincide with dispersal events. • CONCLUSIONS We conclude that colonization of areas with novel edaphic conditions via dispersal can trigger shifts of edaphic association. Accordingly, edaphic niche shifts can result from chance events.
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Affiliation(s)
- Markus S Dillenberger
- Institut für Spezielle Botanik, Johannes Gutenberg-Universität Mainz, Bentzelweg 9a, 55099 Mainz, Germany.
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