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Vaz de Sousa D, Greve M, Oberlander KC. Friends without benefits: Extensive cytotype sympatry and polyploid persistence in an African geophyte. AMERICAN JOURNAL OF BOTANY 2024:e16291. [PMID: 38439133 DOI: 10.1002/ajb2.16291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 12/08/2023] [Accepted: 12/08/2023] [Indexed: 03/06/2024]
Abstract
PREMISE Polyploidy is a major factor in plant adaptation and speciation. Multiple mechanisms contribute to autopolyploid frequency within populations, but uncertainties remain regarding mechanisms that facilitate polyploid establishment and persistence. Here we aimed to document and predict cytotype distributions of Oxalis obliquifolia Steud. ex A. Rich. across Gauteng, South Africa, and test for evidence of possible mechanisms, including morphological, phenological, and reproductive traits, that may potentially facilitate polyploid persistence. METHODS Over 320 O. obliquifolia plants from 25 sites were cytotyped using flow cytometry, and DNA ploidy was confirmed using meiotic chromosome squashes. Cytotypes were mapped and correlations with abiotic variables assessed using ordinations. To assess morphological and phenological associations with cytotype, we grew multiple cytotypes in a common garden, measured phenotypic traits and compared them using linear models and discriminant analyses. Intercytotype reproductive isolation was assessed using crossing experiments, and AMOVAs based on ITS DNA sequences tested for cytogeographic structure. RESULTS Six cytotypes were identified, and most sites had multiple cytotypes. Abiotic variables were not predictive of cytotype distribution. A clear gigas effect was present. Differences in flower size and phenology suggested pollinator interactions could play a role in polyploid persistence. Intercytotype crosses produced seed at low frequency. DNA data suggested diploids and polyploids were largely reproductively isolated in situ, and polyploidization events were not frequent enough to explain high cytotype sympatry. CONCLUSIONS Diploids and polyploids are behaving as separate species, despite little observable niche differentiation and non-zero potential intercytotype seed set. Tests on biotic interactions and intercytotype F1 fitness may provide insights into diploid and polyploid coexistence.
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Affiliation(s)
- Damian Vaz de Sousa
- Department of Plant and Soil Science, University of Pretoria, Private Bag X20, Hatfield, 0028, Pretoria, South Africa
- H.G.W.J. Schweickerdt Herbarium, Department of Plant and Soil Science, University of Pretoria, Pretoria, South Africa
| | - Michelle Greve
- Department of Plant and Soil Science, University of Pretoria, Private Bag X20, Hatfield, 0028, Pretoria, South Africa
| | - Kenneth C Oberlander
- H.G.W.J. Schweickerdt Herbarium, Department of Plant and Soil Science, University of Pretoria, Pretoria, South Africa
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Hajrudinović-Bogunić A, Frajman B, Schönswetter P, Siljak-Yakovlev S, Bogunić F. Apomictic Mountain Whitebeam (Sorbus austriaca, Rosaceae) Comprises Several Genetically and Morphologically Divergent Lineages. BIOLOGY 2023; 12:biology12030380. [PMID: 36979072 PMCID: PMC10045669 DOI: 10.3390/biology12030380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/22/2023] [Accepted: 02/23/2023] [Indexed: 03/04/2023]
Abstract
The interplay of polyploidisation, hybridization, and apomixis contributed to the exceptional diversity of Sorbus (Rosaceae), giving rise to a mosaic of genetic and morphological entities. The Sorbus austriaca species complex from the mountains of Central and South-eastern Europe represents an allopolyploid apomictic system of populations that originated following hybridisation between S. aria and S. aucuparia. However, the mode and frequency of such allopolyploidisations and the relationships among different, morphologically more or less similar populations that have often been described as different taxa remain largely unexplored. We used amplified fragment length polymorphism (AFLP) fingerprinting, plastid DNA sequencing, and analyses of nuclear microsatellites, along with multivariate morphometrics and ploidy data, to disentangle the relationships among populations within this intricate complex. Our results revealed a mosaic of genetic lineages—many of which have not been taxonomically recognised—that originated via multiple allopolyploidisations. The clonal structure within and among populations was then maintained via apomixis. Our results thus support previous findings that hybridisation, polyploidization, and apomixis are the main drivers of Sorbus diversification in Europe.
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Affiliation(s)
| | - Božo Frajman
- Department of Botany, University of Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria
- Correspondence: (B.F.); (F.B.)
| | - Peter Schönswetter
- Department of Botany, University of Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria
| | - Sonja Siljak-Yakovlev
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, AgroParisTech, Université Paris-Saclay, 91400 Orsay, France
| | - Faruk Bogunić
- Faculty of Forestry, University of Sarajevo, Zagrebačka 20, 71000 Sarajevo, Bosnia and Herzegovina
- Correspondence: (B.F.); (F.B.)
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Kolarčik V, Mirková M, Mikoláš V. Reproduction Modes and Conservation Implications in Three Polyploid Sorbus Stenoendemics in Eastern Slovakia (Central Europe). PLANTS (BASEL, SWITZERLAND) 2023; 12:373. [PMID: 36679086 PMCID: PMC9863969 DOI: 10.3390/plants12020373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/07/2023] [Accepted: 01/10/2023] [Indexed: 06/17/2023]
Abstract
The remarkable species diversity of the genus Sorbus is a result of polyploidization and frequent hybridization between interacting species of different cytotypes. Moreover, hybridization is possible between several parental taxa. Gametophytic apomixis, which is common among polyploid Sorbus taxa, indicates the role of clonal reproduction in the evolutionary stabilization of hybridogeneous genotypes. The precise determination of the origin of seeds and their quantitative evaluation may elucidate inter-cytotype interactions, the potential role of mixed-cytotype populations in evolutionary success, and the long-term survival of some hybrid species. We investigated the reproduction modes of selected species of Sorbus in mixed-cytotype populations in eastern Slovakia, Central Europe. We determined the pollen quality, seed production rate, and the ploidy level of mature trees, as well as the origin of the embryo and endosperm in seeds of the stenoendemics S. amici-petri, S. dolomiticola, and S. hornadensis. The tetraploids S. amici-petri and S. hornadensis are characterized by regular and highly stainable pollen grains and reproduce predominantly via pseudogamous apomixis. In contrast, triploid S. dolomiticola usually has oval, heterogenous, and weakly stainable pollen grains, suggesting male meiotic irregularities. Although seeds originate via pseudogamous apomixis in S. dolomiticola as well, the ploidy level of sperm cells participating in the fertilization of central cells is usually determined by co-occurring species of different cytotypes. This suggests that maintaining mating partners is necessary for the long-term survival of a triploid species. We documented rare BIII hybrids and the residual sexuality in tetraploids. The distribution of seeds of meiotic and apomeiotic origins in S. amici-petri shows bimodal characteristics; however, genotypes with predominantly sexual seed types are rare. Reproduction modes documented in polyploid stenoendemics of Sorbus and inferred microevolutionary intercytotype relationships highlight the mixed-cytotype populations as the source of biodiversity in apomictic plant complexes. We suggest that conservation efforts should focus on maintaining the species and cytotypic diversity of Sorbus populations, especially when it comes to the conservation of triploid species.
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Affiliation(s)
- Vladislav Kolarčik
- Institute of Biology and Ecology, Faculty of Science, Pavol Jozef Šafárik University, Mánesova 23, SK-041 54 Košice, Slovakia
| | - Mária Mirková
- Institute of Biology and Ecology, Faculty of Science, Pavol Jozef Šafárik University, Mánesova 23, SK-041 54 Košice, Slovakia
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Boza Espinoza TE, Kessler M. A monograph of the genus Polylepis (Rosaceae). PHYTOKEYS 2022; 203:1-274. [PMID: 36761034 PMCID: PMC9849045 DOI: 10.3897/phytokeys.203.83529] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/13/2022] [Indexed: 05/27/2023]
Abstract
We present a monograph of the high Andean tree genus Polylepis (Rosaceae), based on a species concept considering morphological, climatic and biogeographic distinctness as indicators of evolutionary independence. In total, we recognize 45 species of Polylepis, grouped in five sections. Polylepissect.Sericeae is represented by 15 species in four subsections, P.sect.Reticulatae by seven species, P.sect.Subsericantes by three species, P.sect.Australes by two species and P.sect.Incanaee by three subsections with 18 species. We describe seven new species, one from Colombia (P.frontinensis), one from Ecuador (P.simpsoniae) and five from Peru (P.acomayensis, P.fjeldsaoi, P.occidentalis, P.pilosissima and P.sacra). Three species from Peru (P.albicans, P.pallidistigma and P.serrata) are re-instated as valid species. Two taxa from Bolivia (P.incanoides and P.nana) are elevated from subspecies to species rank. The morphology, habitat, distribution, ecology and conservation status of each species are documented. We also provide an identification key to the species of the genus and general introductions on taxonomic history, morphology, evolution, ecology and conservation.
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Affiliation(s)
- Tatiana Erika Boza Espinoza
- Institute for Nature, Earth and Energy (INTE), Pontificia Universidad Católica del Perú (PUCP), Av. Universitaria 1801, Lima 15088, PeruPontificia Universidad Católica del Perú (PUCP)LimaPeru
| | - Michael Kessler
- Department of Systematic and Evolutionary Botany, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, SwitzerlandUniversity of ZurichZürichSwitzerland
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Fernández P, Hidalgo O, Juan A, Leitch IJ, Leitch AR, Palazzesi L, Pegoraro L, Viruel J, Pellicer J. Genome Insights into Autopolyploid Evolution: A Case Study in Senecio doronicum (Asteraceae) from the Southern Alps. PLANTS 2022; 11:plants11091235. [PMID: 35567236 PMCID: PMC9099586 DOI: 10.3390/plants11091235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 04/27/2022] [Accepted: 04/29/2022] [Indexed: 11/16/2022]
Abstract
Polyploidy is a widespread phenomenon across angiosperms, and one of the main drivers of diversification. Whilst it frequently involves hybridisation, autopolyploidy is also an important feature of plant evolution. Minority cytotypes are frequently overlooked due to their lower frequency in populations, but the development of techniques such as flow cytometry, which enable the rapid screening of cytotype diversity across large numbers of individuals, is now providing a more comprehensive understanding of cytotype diversity within species. Senecio doronicum is a relatively common daisy found throughout European mountain grasslands from subalpine to almost nival elevations. We have carried out a population-level cytotype screening of 500 individuals from Tête Grosse (Alpes-de-Haute-Provence, France), confirming the coexistence of tetraploid (28.2%) and octoploid cytotypes (71.2%), but also uncovering a small number of hexaploid individuals (0.6%). The analysis of repetitive elements from short-read genome-skimming data combined with nuclear (ITS) and whole plastid DNA sequences support an autopolyploid origin of the polyploid S. doronicum individuals and provide molecular evidence regarding the sole contribution of tetraploids in the formation of hexaploid individuals. The evolutionary impact and resilience of the new cytotype have yet to be determined, although the coexistence of different cytotypes may indicate nascent speciation.
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Affiliation(s)
- Pol Fernández
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s.n., Parc de Montjuïc, 08038 Barcelona, Spain;
- Correspondence: (P.F.); (J.P.); Tel.: +34-932890611 (P.F. & J.P.)
| | - Oriane Hidalgo
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s.n., Parc de Montjuïc, 08038 Barcelona, Spain;
- Royal Botanic Gardens, Kew, Kew Green, Richmond TW9 3AE, UK; (I.J.L.); (J.V.)
| | - Ana Juan
- Departamento de Ciencias Ambientales y Recursos Naturales, Universidad de Alicante, 03080 Alicante, Spain;
| | - Ilia J. Leitch
- Royal Botanic Gardens, Kew, Kew Green, Richmond TW9 3AE, UK; (I.J.L.); (J.V.)
| | - Andrew R. Leitch
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK;
| | - Luis Palazzesi
- Museo Argentino de Ciencias Naturales, CONICET, División Paleobotánica, Buenos Aires C1405DJR, Argentina;
| | - Luca Pegoraro
- Biodiversity and Conservation Biology Research Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Bimensdorf, Switzerland;
| | - Juan Viruel
- Royal Botanic Gardens, Kew, Kew Green, Richmond TW9 3AE, UK; (I.J.L.); (J.V.)
| | - Jaume Pellicer
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s.n., Parc de Montjuïc, 08038 Barcelona, Spain;
- Royal Botanic Gardens, Kew, Kew Green, Richmond TW9 3AE, UK; (I.J.L.); (J.V.)
- Correspondence: (P.F.); (J.P.); Tel.: +34-932890611 (P.F. & J.P.)
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Wang L, Ding J, Borrell JS, Cheek M, McAllister HA, Wang F, Liu L, Zhang H, Zhang Q, Wang Y, Wang N. Molecular and morphological analyses clarify species delimitation in section Costatae and reveal Betula buggsii sp. nov. (sect. Costatae, Betulaceae) in China. ANNALS OF BOTANY 2022; 129:415-428. [PMID: 35018419 PMCID: PMC8944703 DOI: 10.1093/aob/mcac001] [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: 10/22/2021] [Accepted: 01/05/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND AND AIMS Delineating closely related and morphologically similar species is difficult. Here, we integrate morphology, genetics, ploidy and geography to resolve species and subspecies boundaries in four trees of section Costatae (genus Betula): Betula ashburneri, B. costata, B. ermanii and B. utilis, as well as multiple subspecies and polyploid races. METHODS We genotyped 371 individuals (20-133 per species) from 51 populations at 15 microsatellite markers, as well as a subset of individuals, using restriction-site associated DNA sequencing and nuclear internal transcribed spacers. We determined the ploidy level of eight individuals using flow cytometry and characterized leaf variation for a subset of 109 individuals by morphometric analysis. KEY RESULTS Integration of multiple lines of evidence suggested a series of revisions to the taxonomy of section Costatae. Betula costata and B. ermanii were found to be valid. Molecular and leaf morphology analyses revealed little differentiation between diploid B. albosinensis and some samples of B. utilis ssp. utilis. By contrast, other B. utilis ssp. utilis samples and ssp. albosinensis formed a morphological continuum but differed based on genetics. Specifically, B. utilis ssp. albosinensis was divided into two groups with group I genetically similar to B. utilis ssp. utilis and group II, a distinct cluster, proposed as the new diploid species Betula buggsii sp. nov. Phylogenomic analysis based on 2285 620 single nucleotide polymorphisms identified a well-supported monophyletic clade of B. buggsii. Morphologically, B. buggsii is characterized by elongated lenticels and a distinct pattern of bark peeling and may be geographically restricted to the Qinling-Daba Mountains. CONCLUSIONS Our integrated approach identifies six taxa within section Costatae: B. ashburneri, B. buggsii, B. costata, B. utilis ssp. utilis, B. utilis ssp. albosinensis and B. ermanii. Our research demonstrates the value of an integrative approach using morphological, geographical, genetic and ploidy-level data for species delineation.
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Affiliation(s)
| | | | | | | | - Hugh A McAllister
- School of Life Sciences, Biosciences Building, University of Liverpool, Crown Street, Liverpool, UK
| | - Feifei Wang
- State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River, College of Forestry, Shandong Agricultural University, Tai’an, China
- Mountain Tai Forest Ecosystem Research Station of State Forestry and Grassland Administration, College of Forestry, Shandong Agricultural University, Tai’an, China
| | - Lu Liu
- State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River, College of Forestry, Shandong Agricultural University, Tai’an, China
- Mountain Tai Forest Ecosystem Research Station of State Forestry and Grassland Administration, College of Forestry, Shandong Agricultural University, Tai’an, China
| | - Huayu Zhang
- State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River, College of Forestry, Shandong Agricultural University, Tai’an, China
- Mountain Tai Forest Ecosystem Research Station of State Forestry and Grassland Administration, College of Forestry, Shandong Agricultural University, Tai’an, China
| | - Qiufeng Zhang
- State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River, College of Forestry, Shandong Agricultural University, Tai’an, China
- Mountain Tai Forest Ecosystem Research Station of State Forestry and Grassland Administration, College of Forestry, Shandong Agricultural University, Tai’an, China
| | - Yiming Wang
- State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River, College of Forestry, Shandong Agricultural University, Tai’an, China
- Mountain Tai Forest Ecosystem Research Station of State Forestry and Grassland Administration, College of Forestry, Shandong Agricultural University, Tai’an, China
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Pellicer J, Balant M, Fernández P, Rodríguez González R, Hidalgo O. Morphological and Genome-Wide Evidence of Homoploid Hybridisation in Urospermum (Asteraceae). PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11020182. [PMID: 35050070 PMCID: PMC8779322 DOI: 10.3390/plants11020182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 05/11/2023]
Abstract
The genus Urospermum is distributed in the Mediterranean region and Macaronesia, and has been introduced to other extra-Mediterranean regions. Although the two species constituting the genus, U. dalechampii and U. picroides, are frequently found together, hybrids have so far only been reported once, from Morocco. However, we found certain individuals in Catalonia, whose intermediate morphology suggested a potential hybrid origin. In this study, we applied morphological and molecular methods to investigate the origin of those individuals. Intermediate features at phenotype, karyological, cytogenetic, and genomic levels were identified in morphologically intermediate individuals, supporting their homoploid hybrid origin. Chloroplast sequence data suggest that U. dalechampii is the maternal progenitor of the hybrid. Together with the intermediate traits displayed, the lack of fertile seeds suggests that hybrids are probably F1. Future monitoring studies will be, nonetheless, needed to evaluate the extent of hybridisation and its potential impact on the biology of the genus.
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Affiliation(s)
- Jaume Pellicer
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s.n., Parc de Montjuïc, 08038 Barcelona, Spain; (M.B.); (P.F.); (R.R.G.)
- Royal Botanic Gardens, Kew, Kew Green, Richmond TW9 3AE, UK
- Correspondence: (J.P.); (O.H.); Tel.: +34-932890611 (J.P. & O.H.)
| | - Manica Balant
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s.n., Parc de Montjuïc, 08038 Barcelona, Spain; (M.B.); (P.F.); (R.R.G.)
| | - Pol Fernández
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s.n., Parc de Montjuïc, 08038 Barcelona, Spain; (M.B.); (P.F.); (R.R.G.)
| | - Roi Rodríguez González
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s.n., Parc de Montjuïc, 08038 Barcelona, Spain; (M.B.); (P.F.); (R.R.G.)
| | - Oriane Hidalgo
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s.n., Parc de Montjuïc, 08038 Barcelona, Spain; (M.B.); (P.F.); (R.R.G.)
- Royal Botanic Gardens, Kew, Kew Green, Richmond TW9 3AE, UK
- Correspondence: (J.P.); (O.H.); Tel.: +34-932890611 (J.P. & O.H.)
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Németh C, Papp N, Nosková J, Höhn M. Speciation by triparental hybridization in genus Sorbus (Rosaceae). Biol Futur 2021; 71:209-222. [PMID: 34554510 DOI: 10.1007/s42977-020-00003-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hybridization associated with polyploidization and apomixis is a frequent mechanism of speciation. Sorbus is a genus with ongoing hybridization resulting in a polyploid complex with different parental lineage. Triparens is the smallest hybridogenous subgenus of Sorbus so far known to comprise only two taxa, S. intermedia and S. × liljeforsii that combine the genomes of three taxa (S. aria agg., S. aucuparia and S. torminalis). To elucidate the origins of S. dacica, S. paxiana and S. tauricola, three new trigenomic candidates formerly believed to be of biparental origin with either S. aria agg. × S. aucuparia or S. aria agg. × S. torminalis lineage we combined data from HPLC and chloroplast DNA analysing additional 33 related taxa as well. We concluded that the 'torminalis-type' flavonoid profile and the 'aucuparia-type' plastid indicate the participation of both S. torminalis and S. aucuparia resulting in the formation of S. dacica, S. paxiana and S. tauricola. Sorbus aria agg. as the third ancestor and as a necessary link to meet genes of S. torminalis and S. aucuparia in one genome is obvious from morphological features (densely tomentose undersides of leaves). The tetraploid cytotypes and obligate pseudogamy of S. dacica and S. paxiana were determined by flow cytometry and are published here for the first time. The most probable evolutionary scenario for Triparens species is: 1. a diploid sexual S. aucuparia as pollen acceptor hybridized with a tetraploid apomictic taxon from the S. aria agg. producing a triploid apomictic taxon with 'aucuparia-type' plastid inherited maternally; 2. during a second crossing event this subgenus Soraria hybrid as maternal progenitor hybridized with the sexual diploid S. torminalis (providing gene(s) of apigenin O-glucuronide synthesis) forming a tetraploid Triparens hybrid with 'aucuparia-type' plastid and 'torminalis-type' flavonoids.
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Affiliation(s)
- Csaba Németh
- GINOP Sustainable Ecosystems Group, MTA Centre for Ecological Research, Klebersberg Kuno út 3, Tihany, 8237, Hungary. .,Department of Botany and Soroksár Botanical Garden, Faculty of Horticultural Science, Szent István University, Budapest, Hungary.
| | - Nóra Papp
- Department of Applied Chemistry, Faculty of Food Science, Szent István University, Budapest, Hungary
| | - Jana Nosková
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic
| | - Mária Höhn
- Department of Botany and Soroksár Botanical Garden, Faculty of Horticultural Science, Szent István University, Budapest, Hungary
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Pellicer J, López-Pujol J, Aixarch M, Garnatje T, Vallès J, Hidalgo O. Detecting Introgressed Populations in the Iberian Endemic Centaurea podospermifolia through Genome Size. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10081492. [PMID: 34451537 PMCID: PMC8401423 DOI: 10.3390/plants10081492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/15/2021] [Accepted: 07/19/2021] [Indexed: 05/25/2023]
Abstract
Based on results from previous studies, populations of the Iberian endemic Centaurea podospermifolia north of the Ebro River are considered genetically pure, while those southward are introgressed, with genetic input from C. cephalariifolia. This phenomenon is particularly relevant, especially given both the endangered and protected status for the species, which can have consequences in how to best apply conservation strategies to maintain genetic resources in the species. The main goal of this study was to evaluate whether genome size assessments using flow cytometry can help distinguishing between pure, hybrid and introgressed populations, and hence become a powerful and cost-effective tool to complement comprehensive population genetic surveys. The results indicate that there are significant genome size differences between populations of C. podospermifolia, which are coincident with previous considerations of pure and introgressed populations. Given the simplicity and reproducibility of this technique, flow cytometry could become an effective tool for monitoring pure populations of this species and, indeed, become an integral part of the management plans that are mandatory for listed taxa.
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Affiliation(s)
- Jaume Pellicer
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s.n., Parc de Montjuïc, Catalonia, 08038 Barcelona, Spain; (J.L.-P.); (T.G.)
- Royal Botanic Gardens, Kew, Richmond TW9 3AE, UK
| | - Jordi López-Pujol
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s.n., Parc de Montjuïc, Catalonia, 08038 Barcelona, Spain; (J.L.-P.); (T.G.)
| | - Marc Aixarch
- c/Mossèn Manyà 15, Catalonia, 43500 Tortosa, Spain;
| | - Teresa Garnatje
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s.n., Parc de Montjuïc, Catalonia, 08038 Barcelona, Spain; (J.L.-P.); (T.G.)
| | - Joan Vallès
- Laboratori de Botànica, Unitat Associada al CSIC, Facultat de Farmàcia i Ciències de l’Alimentació, Institut de la Biodiversitat IRBio, Universitat de Barcelona, Av. Joan XXIII 27-31, Catalonia, 08028 Barcelona, Spain;
| | - Oriane Hidalgo
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s.n., Parc de Montjuïc, Catalonia, 08038 Barcelona, Spain; (J.L.-P.); (T.G.)
- Royal Botanic Gardens, Kew, Richmond TW9 3AE, UK
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Kšiňan S, Ďurišová Ľ, Eliáš P. Genome size estimation of Cotoneaster species (Rosaceae) from the Western Carpathians. Biologia (Bratisl) 2021. [DOI: 10.1007/s11756-021-00772-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Li J, Zhu K, Wang Q, Chen X. Genome size variation and karyotype diversity in eight taxa of Sorbus sensu stricto (Rosaceae) from China. COMPARATIVE CYTOGENETICS 2021; 15:137-148. [PMID: 34055237 PMCID: PMC8159915 DOI: 10.3897/compcytogen.v15i2.58278] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 04/28/2021] [Indexed: 05/27/2023]
Abstract
Eight taxa of Sorbus Linnaeus, 1753 sensu stricto (Rosaceae) from China have been studied karyologically through chromosome counting, chromosomal measurement and karyotype symmetry. Genome size was also estimated by flow cytometry. Six taxa, S. amabilis Cheng ex T.T.Yu et K.C.Kuan, 1963, S. hupehensis var. paucijuga (D.K. Zang et P.C. Huang, 1992) L.T. Lu, 2000, S. koehneana C.K. Schneider, 1906, S. pohuashanensis (Hance, 1875) Hedlund, 1901, S. scalaris Koehne, 1913 and S. wilsoniana C.K. Schneider, 1906 are diploids with 2n = 34, whereas two taxa, S. filipes Handel-Mazzetti,1933 and S. ovalis McAllister, 2005 are tetraploid with 2n = 68. In general, the chromosome size is mainly small, and karyotypes are symmetrical with predominance of metacentric chromosomes. Genome size variation of diploids and tetraploids is 1.401 pg -1.676 pg and 2.674 pg -2.684 pg, respectively. Chromosome numbers of S. amabilis and S. hupehensis var. paucijuga, and karyotype and genome size of eight taxa studied are reported for the first time. This study emphasised the reliability of flow cytometry in genome size determination to infer ploidy levels in Chinese native Sorbus species.
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Affiliation(s)
- Jiabao Li
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, Jiangsu, ChinaNanjing Forestry UniversityNanjingChina
| | - Kailin Zhu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, Jiangsu, ChinaNanjing Forestry UniversityNanjingChina
| | - Qin Wang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, Jiangsu, ChinaNanjing Forestry UniversityNanjingChina
| | - Xin Chen
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, Jiangsu, ChinaNanjing Forestry UniversityNanjingChina
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Christenhusz MJM, Chase MW, Fay MF, Hidalgo O, Leitch IJ, Pellicer J, Viruel J. Biogeography and genome size evolution of the oldest extant vascular plant genus, Equisetum (Equisetaceae). ANNALS OF BOTANY 2021; 127:681-695. [PMID: 33598697 PMCID: PMC8052921 DOI: 10.1093/aob/mcab005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 01/09/2021] [Indexed: 05/25/2023]
Abstract
BACKGROUND AND AIMS Extant plant groups with a long fossil history are key elements in understanding vascular plant evolution. Horsetails (Equisetum, Equisetaceae) have a nearly continuous fossil record dating back to the Carboniferous, but their phylogenetic and biogeographic patterns are still poorly understood. We use here the most extensive phylogenetic analysis to date as a framework to evaluate their age, biogeography and genome size evolution. METHODS DNA sequences of four plastid loci were used to estimate divergence times and investigate the biogeographic history of all extant species of Equisetum. Flow cytometry was used to study genome size evolution against the framework of phylogenetic relationships in Equisetum. KEY RESULTS On a well-supported phylogenetic tree including all extant Equisetum species, a molecular clock calibrated with multiple fossils places the node at which the outgroup and Equisetum diverged at 343 Mya (Early Carboniferous), with the first major split among extant species occurring 170 Mya (Middle Jurassic). These dates are older than those reported in some other recent molecular clock studies but are largely in agreement with a timeline established by fossil appearance in the geological record. Representatives of evergreen subgenus Hippochaete have much larger genome sizes than those of deciduous subgenus Equisetum, despite their shared conserved chromosome number. Subgenus Paramochaete has an intermediate genome size and maintains the same number of chromosomes. CONCLUSIONS The first divergences among extant members of the genus coincided with the break-up of Pangaea and the resulting more humid, warmer climate. Subsequent tectonic activity most likely involved vicariance events that led to species divergences combined with some more recent, long-distance dispersal events. We hypothesize that differences in genome size between subgenera may be related to the number of sperm flagellae.
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Affiliation(s)
- Maarten J M Christenhusz
- Royal Botanic Gardens, Kew, Richmond, UK
- Department of Environment and Agriculture, Curtin University, Perth, WA, Australia
| | - Mark W Chase
- Royal Botanic Gardens, Kew, Richmond, UK
- Department of Environment and Agriculture, Curtin University, Perth, WA, Australia
| | - Michael F Fay
- Royal Botanic Gardens, Kew, Richmond, UK
- School of Biological Sciences, The University of Western Australia, Perth WA, Australia
| | - Oriane Hidalgo
- Royal Botanic Gardens, Kew, Richmond, UK
- Laboratori de Botànica, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona, Barcelona, Spain
| | | | - Jaume Pellicer
- Royal Botanic Gardens, Kew, Richmond, UK
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Barcelona, Spain
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13
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Hebda A, Kempf M, Wachowiak W, Pluciński B, Kauzal P, Zwijacz-Kozica T. Hybridization and introgression of native and foreign Sorbus tree species in unique environments of protected mountainous areas. AOB PLANTS 2021; 13:plaa070. [PMID: 33604013 PMCID: PMC7877695 DOI: 10.1093/aobpla/plaa070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 12/22/2020] [Indexed: 06/12/2023]
Abstract
Hybridization and introgression are important processes influencing the genetic diversity and evolution of species. These processes are of particular importance in protected areas, where they can lead to the formation of hybrids between native and foreign species and may ultimately result in the loss of parental species from their natural range. Despite their importance, the contribution of hybridization and introgression to genetic diversity in Sorbus genus remains not fully recognized. We analysed the genetic and morphological variability of several Sorbus species including native (Sorbus aria), foreign (S. intermedia) and potentially hybrid (S. carpatica) individuals from the Polish Carpathian range. Patterns of variation at 13 nuclear microsatellite loci show hybridization between the tested species and confirm the existence of the hybrid form S. carpatica. Biometric analysis on leaves, based of 10 metric features and three parameters, identified several characters for preliminary taxonomic classification; however, none of them could be used as a fully diagnostic marker for faultless annotation of S. intermedia and S. carpatica. The genetic structure analysis indicated complex patterns of population differentiation and its diverse origin. The results allow assessment of genetic variation and identification of parental species participating in hybridization. This knowledge will advance the management of genetic diversity and development of conservation strategies for efficient maintenance of the unique protected ecosystem.
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Affiliation(s)
- Anna Hebda
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University in Kraków, Kraków, Poland
| | - Marta Kempf
- Department of Genetics and Forest Tree Breeding, Institute of Forest Ecology and Silviculture, Faculty of Forestry, University of Agriculture in Krakow, Kraków, Poland
| | - Witold Wachowiak
- Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland
| | - Bartosz Pluciński
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University in Kraków, Kraków, Poland
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Boza Espinoza TE, Popp V, Kessler M. Guard cell sizes and ploidy levels in Polylepis (Rosaceae). NEOTROPICAL BIODIVERSITY 2020. [DOI: 10.1080/23766808.2020.1844992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Affiliation(s)
- Tatiana Erika Boza Espinoza
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland
- Universidad Nacional de San Antonio Abad del Cusco, Herbario Vargas CUZ, Cusco, Perú
| | | | - Michael Kessler
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland
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Hamston TJ, de Vere N, King RA, Pellicer J, Fay MF, Cresswell JE, Stevens JR. Apomixis and Hybridization Drives Reticulate Evolution and Phyletic Differentiation in Sorbus L.: Implications for Conservation. FRONTIERS IN PLANT SCIENCE 2018; 9:1796. [PMID: 30619388 PMCID: PMC6300497 DOI: 10.3389/fpls.2018.01796] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 11/19/2018] [Indexed: 06/09/2023]
Abstract
Hybridization and polyploidy are major forces in the evolution of plant diversity and the study of these processes is of particular interest to understand how novel taxa are formed and how they maintain genetic integrity. Sorbus is an example of a genus where active diversification and speciation are ongoing and, as such, represents an ideal model to investigate the roles of hybridization, polyploidy and apomixis in a reticulate evolutionary process. To elucidate breeding systems and evolutionary origins of a complex of closely related Sorbus taxa, we assessed genotypic diversity and population structure within and among taxa, combining data from nuclear DNA microsatellite markers and flow cytometry. Clonal analysis and low genotypic diversity within the polyploid taxa suggest apomixis is obligate. However, genetic variation has led to groups of 'clone-mates' within apomictic taxa that strongly suggest mutation is responsible for the genotypic diversity of these apomictic lineages. In addition, microsatellite profiles and site demographics suggest hybridization events among apomictic polyploid Sorbus may have contributed to the extant diversity of recognized taxa in this region. This research demonstrates that both macro- and micro-evolutionary processes are active within this reticulate Sorbus complex. Conservation measures should be aimed at maintaining this process and should therefore be prioritized for those areas of Sorbus species richness where the potential for interspecific gene flow is greatest.
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Affiliation(s)
- Tracey J. Hamston
- Molecular Ecology and Evolution Group, Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
- Field Conservation and Research Department, Whitley Wildlife Conservation Trust, Paignton, United Kingdom
| | - Natasha de Vere
- National Botanic Garden of Wales, Llanarthney, United Kingdom
- Faculty of Earth and Life Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - R. Andrew King
- Molecular Ecology and Evolution Group, Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Jaume Pellicer
- Jodrell Laboratory, Royal Botanic Gardens, Kew, United Kingdom
| | - Michael F. Fay
- Jodrell Laboratory, Royal Botanic Gardens, Kew, United Kingdom
- School of Plant Biology, University of Western Australia, Crawley, WA, Australia
| | - James E. Cresswell
- Molecular Ecology and Evolution Group, Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Jamie R. Stevens
- Molecular Ecology and Evolution Group, Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
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Abreu JA, Hawkins JA, Cotrim H, Fay MF, Hidalgo O, Pellicer J. Ophrys fusca and Ophrys dyris (Orchidaceae) – constancy of tetraploidy amongst populations in Central Portugal. ACTA ACUST UNITED AC 2017. [DOI: 10.1080/20423489.2017.1408185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- J. A. Abreu
- Centre for Ecology, Evolution and Evironmental Changes (CE3C), Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
- Conservation Science, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3DS, UK
- School of Biological Sciences, University of Reading, Whiteknights, Reading, Berkshire RG6 6BX, UK
| | - J. A. Hawkins
- School of Biological Sciences, University of Reading, Whiteknights, Reading, Berkshire RG6 6BX, UK
| | - H. Cotrim
- Centre for Ecology, Evolution and Evironmental Changes (CE3C), Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| | - M. F. Fay
- Conservation Science, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3DS, UK
- School of Plant Biology, University of Western Australia, Crawley, WA 6009, Australia
| | - O. Hidalgo
- Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Richmond, Surrey, TW3 3DS, UK
| | - J. Pellicer
- Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Richmond, Surrey, TW3 3DS, UK
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Uhrinová V, Zozomová-Lihová J, Bernátová D, Paule J, Paule L, Gömöry D. Origin and genetic differentiation of pink-flowered Sorbus hybrids in the Western Carpathians. ANNALS OF BOTANY 2017; 120:271-284. [PMID: 28334280 PMCID: PMC5737586 DOI: 10.1093/aob/mcx013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 01/09/2017] [Indexed: 05/28/2023]
Abstract
BACKGROUND AND AIMS Diversity of the genus Sorbus has been affected by interspecific hybridizations. Pink-flowered hybrid species have been insufficiently studied so far. They comprise bigenomic hybrid species derived from crosses S. aria s.l. × S. chamaemespilus and trigenomic ones, where S. aucuparia was involved as well. The main objective of the present study was to reconstruct their hybrid origins as well as to assess genetic distinction among several morphologically recognized hybrid species. METHODS Samples from putative maternal species and eight pink-flowered and two white-flowered hybrid species were collected in the Western Carpathians and the Sudetes. In total, 370 specimens were analysed. Six chloroplast microsatellites were used to infer parentage, whereas nuclear amplified fragment length polymorphism (AFLP) markers were employed for the identification of clones and patterns of genetic variation. Ploidy levels were estimated by flow cytometry on a subset of 140 individuals. KEY RESULTS Genetic data supported their hybrid origins proposed based on flower and leaf morphology, and chloroplast DNA (cpDNA) revealed recurrent origins ( S. caeruleomontana , S. haljamovae ), even from bidirectional hybridization events ( S. zuzanae ). All bigenomic and trigenomic hybrid species (except triploid S. zuzanae ) were found to be tetraploid. In addition to polyploidy, low genetic variation and the presence of clones within and among populations were observed, suggesting predominantly apomictic reproduction of the hybrid species. Most of the described hybrid species appeared also genetically distinct. CONCLUSIONS The data suggest that multiple hybridization events in the Western Carpathian Sorbus have led to the formation of separate, partially reproductively isolated genetic lineages, which may or may not be discriminated morphologically. Even bidirectional hybridization can produce individuals classified to the same taxon based on phenotype. For some hybrid taxa, hybridization pathways were proposed based on their genetic proximity to parental species and differences in genome sizes.
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Affiliation(s)
- Veronika Uhrinová
- Technical University in Zvolen, Faculty of Forestry, TG Masaryka 24, 96053 Zvolen, Slovakia
| | - Judita Zozomová-Lihová
- Slovak Academy of Sciences, Institute of Botany, Plant Science and Biodiversity Centre, Dúbravská cesta 9, 84523 Bratislava, Slovakia
| | - Dana Bernátová
- Comenius University, Botanical Garden, Detached Unit, 03815 Blatnica 315, Slovakia
| | - Juraj Paule
- Senckenberg Research Institute and Natural History Museum, Department of Botany and Molecular Evolution, Senckenberganlage 25, 60325 Frankfurt am Main, Germany
| | - Ladislav Paule
- Technical University in Zvolen, Faculty of Forestry, TG Masaryka 24, 96053 Zvolen, Slovakia
| | - Dušan Gömöry
- Technical University in Zvolen, Faculty of Forestry, TG Masaryka 24, 96053 Zvolen, Slovakia
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18
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Molecular phylogenetics and historical biogeography of Sorbus sensu stricto (Rosaceae). Mol Phylogenet Evol 2017; 111:76-86. [DOI: 10.1016/j.ympev.2017.03.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 03/15/2017] [Accepted: 03/21/2017] [Indexed: 11/24/2022]
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Hamston TJ, Wilson RJ, de Vere N, Rich TCG, Stevens JR, Cresswell JE. Breeding system and spatial isolation from congeners strongly constrain seed set in an insect-pollinated apomictic tree: Sorbus subcuneata (Rosaceae). Sci Rep 2017; 7:45122. [PMID: 28338049 PMCID: PMC5364488 DOI: 10.1038/srep45122] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 02/16/2017] [Indexed: 02/07/2023] Open
Abstract
In plants, apomixis results in the production of clonal offspring via seed and can provide reproductive assurance for isolated individuals. However, many apomicts require pollination to develop functional endosperm for successful seed set (pseudogamy) and therefore risk pollination-limitation, particularly in self-incompatible species that require heterospecific pollen. We used microsatellite paternity analysis and hand pollinations to investigate pollen-limitation in Sorbus subcuneata, a threatened endemic tree that co-occurs with its congener, S. admonitor. We confirmed that S. subcuneata is an obligate pseudogamous apomict, but open-pollinated flowers rarely produced seed (flower-to-seed conversion < 1%) even though they rapidly accumulated pollen on their stigmas. Manual heterospecific pollination by S. admonitor resulted in a high flower-to-seed conversion rate (65%), however, we estimate that the ratio of self: heterospecific pollination in open-pollinated flowers was at least 22:1. Despite the efficacy of heterospecific pollination, the contribution of S. admonitor trees to paternity in seed from open-pollinated flowers of S. subcuneata decreased rapidly with the spatial separation between paternal and maternal trees. Conservation efforts aimed at maintaining species with this breeding system must therefore manage the congeners in tandem which will also maintain the potential for rare heterospecific fertilisation that typically cause rapid diversification in these lineages.
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Affiliation(s)
- Tracey J Hamston
- Biosciences, University of Exeter, Exeter, Devon, UK.,Whitley Wildlife Conservation Trust, Paignton Zoo, Paignton, UK
| | | | - Natasha de Vere
- National Botanic Garden of Wales, Llanarthne, UK.,Institute of Biological Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, UK
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Piñeiro R, Karrman-Bailey F, Cowan RS, Fay MF. Isolation and characterization of microsatellite loci in Sorbus porrigentiformis and cross-amplification in S. aria and S. rupicola (Rosaceae). APPLICATIONS IN PLANT SCIENCES 2017; 5:apps1600150. [PMID: 28224061 PMCID: PMC5315384 DOI: 10.3732/apps.1600150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 12/31/2016] [Indexed: 05/25/2023]
Abstract
PREMISE OF THE STUDY Southwestern Britain is an emblematic hotspot of polyploid diversity of whitebeams (Sorbus aria agg.; Rosaceae) with ca. 30 polyploid endemic species. The tetraploid S. porrigentiformis is postulated as one of the parents of most of these endemics, along with the sexual diploid S. aria s. str. and the tetraploid S. rupicola. METHODS AND RESULTS We isolated 16 nuclear microsatellite loci from S. porrigentiformis and characterized them on 45 trees representing the three putative parental species. Eleven loci were polymorphic, and eight of them exhibited species-specific alleles. Allele numbers ranged from one to 11, and observed heterozygosity ranged from 0.40 to 1.00. The intraspecific levels of variation were very low, in agreement with the facultative apomictic reproduction hypothesized for this species. CONCLUSIONS The species-specific alleles will be useful for tracing the origin of the narrowly distributed Sorbus taxa. In addition, the assessment of diversity levels will help design a conservation strategy for the polyploid complex.
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Affiliation(s)
- Rosalía Piñeiro
- Jodrell Laboratory, Royal Botanic Gardens, Kew, TW9 3DS Richmond, Surrey, United Kingdom
| | - Freja Karrman-Bailey
- Jodrell Laboratory, Royal Botanic Gardens, Kew, TW9 3DS Richmond, Surrey, United Kingdom
| | - Robyn S. Cowan
- Jodrell Laboratory, Royal Botanic Gardens, Kew, TW9 3DS Richmond, Surrey, United Kingdom
| | - Michael F. Fay
- Jodrell Laboratory, Royal Botanic Gardens, Kew, TW9 3DS Richmond, Surrey, United Kingdom
- School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
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Detecting Mechanisms of Karyotype Evolution in Heterotaxis (Orchidaceae). PLoS One 2016; 11:e0165960. [PMID: 27832130 PMCID: PMC5104408 DOI: 10.1371/journal.pone.0165960] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 10/20/2016] [Indexed: 01/22/2023] Open
Abstract
The karyotype is shaped by different chromosome rearrangements during species evolution. However, determining which rearrangements are responsible for karyotype changes is a challenging task and the combination of a robust phylogeny with refined karyotype characterization, GS measurements and bioinformatic modelling is necessary. Here, this approach was applied in Heterotaxis to determine what chromosome rearrangements were responsible for the dysploidy variation. We used two datasets (nrDNA and cpDNA, both under MP and BI) to infer the phylogenetic relationships among Heterotaxis species and the closely related genera Nitidobulbon and Ornithidium. Such phylogenies were used as framework to infer how karyotype evolution occurred using statistical methods. The nrDNA recovered Ornithidium, Nitidobulbon and Heterotaxis as monophyletic under both MP and BI; while cpDNA could not completely separate the three genera under both methods. Based on the GS, we recovered two groups within Heterotaxis: (1) "small GS", corresponding to the Sessilis grade, composed of plants with smaller genomes and smaller morphological structure, and (2) "large GS", corresponding to the Discolor clade, composed of plants with large genomes and robust morphological structures. The robust karyotype modeling, using both nrDNA phylogenies, allowed us to infer that the ancestral Heterotaxis karyotype presented 2n = 40, probably with a proximal 45S rDNA on a metacentric chromosome pair. The chromosome number variation was caused by ascending dysploidy (chromosome fission involving the proximal 45S rDNA site resulting in two acrocentric chromosome pairs holding a terminal 45S rDNA), with subsequent descending dysploidy (fusion) in two species, H. maleolens and H. sessilis. However, besides dysploidy, our analysis detected another important chromosome rearrangement in the Orchidaceae: chromosome inversion, that promoted 5S rDNA site duplication and relocation.
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Burgess MB, Cushman KR, Doucette ET, Frye CT, Campbell CS. Understanding diploid diversity: A first step in unraveling polyploid, apomictic complexity in Amelanchier. AMERICAN JOURNAL OF BOTANY 2015; 102:2041-2057. [PMID: 26643889 DOI: 10.3732/ajb.1500330] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 10/05/2015] [Indexed: 06/05/2023]
Abstract
PREMISE OF THE STUDY Delimitation of Amelanchier species is difficult because of polyploidy and gametophytic apomixis. A first step in unraveling this species problem is understanding the diversity of the diploids that contributed genomes to polyploid apomicts. This research helps clarify challenging species-delimitation problems attending polyploid, apomictic complexity. METHODS We sampled 431 diploid accessions from 13 species, of which 10 are North American and three are Old World. Quantitative morphological analyses tested the null hypothesis of no discrete groups. Using three to nine diploid accessions per species, we constructed phylogenies with DNA sequences from ETS, ITS, the second intron of LEAFY, and chloroplast regions rpoB-trnC, rpl16, trnD-trnT, and ycf6-psbM. KEY RESULTS Most Amelanchier diploid taxa are morphologically and ecogeographically distinct and genetically exclusive lineages. They rarely hybridize with one another. Nuclear and chloroplast DNA sequences almost completely resolve the Amelanchier phylogeny. The backbone is the mostly western North American clade A, eastern North American clade B, and Old World clade O. DNA sequences and morphology support clades A and O as sister taxa. Despite extensive paralogy, our LEAFY data are phylogenetically informative and identify a clade (T) of three arborescent taxa within clade B. CONCLUSIONS Amelanchier diploids differ strikingly from polyploid apomicts, in that hybridization among them is rare, and they form taxa that would qualify as species by most species concepts. Knowledge of diploid morphology, phylogeny, and ecogeography provides a foundation for understanding the evolutionary history of polyploid apomicts, their patterns of diversification, and their species status.
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Affiliation(s)
- Michael B Burgess
- Department of Biological Sciences, State University of New York Plattsburgh, Plattsburgh, New York 12901, USA
| | - Kevin R Cushman
- School of Biology and Ecology, University of Maine, Orono, Maine 04469, USA
| | - Eric T Doucette
- School of Biology and Ecology, University of Maine, Orono, Maine 04469, USA
| | - Christopher T Frye
- Maryland Department of Natural Resources, Natural Heritage Program, 909 Wye Mills Road, Wye Mills, Maryland 21679, USA
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Hajrudinović A, Siljak-Yakovlev S, Brown SC, Pustahija F, Bourge M, Ballian D, Bogunić F. When sexual meets apomict: genome size, ploidy level and reproductive mode variation of Sorbus aria s.l. and S. austriaca (Rosaceae) in Bosnia and Herzegovina. ANNALS OF BOTANY 2015; 116:301-12. [PMID: 26113635 PMCID: PMC4512196 DOI: 10.1093/aob/mcv093] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/23/2015] [Accepted: 05/07/2015] [Indexed: 05/10/2023]
Abstract
BACKGROUND AND AIMS Allopolyploidy and intraspecific heteroploid crosses are associated, in certain groups, with changes in the mating system. The genus Sorbus represents an appropriate model to study the relationships between ploidy and reproductive mode variations. Diploid S. aria and tetraploid apomictic S. austriaca were screened for ploidy and mating system variations within pure and sympatric populations in order to gain insights into their putative causalities. METHODS Flow cytometry was used to assess genome size and ploidy level among 380 S. aria s.l. and S. austriaca individuals from Bosnia and Herzegovina, with 303 single-seed flow cytometric seed screenings being performed to identify their mating system. Pollen viability and seed set were also determined. KEY RESULTS Flow cytometry confirmed the presence of di-, tri- and tetraploid cytotype mixtures in mixed-ploidy populations of S. aria and S. austriaca. No ploidy variation was detected in single-species populations. Diploid S. aria mother plants always produced sexually originated seeds, whereas tetraploid S. austriaca as well as triploid S. aria were obligate apomicts. Tetraploid S. aria preserved sexuality in a low portion of plants. A tendency towards a balanced 2m : 1p parental genome contribution to the endosperm was shared by diploids and tetraploids, regardless of their sexual or asexual origin. In contrast, most triploids apparently tolerated endosperm imbalance. CONCLUSIONS Coexistence of apomictic tetraploids and sexual diploids drives the production of novel polyploid cytotypes with predominantly apomictic reproductive modes. The data suggest that processes governing cytotype diversity and mating system variation in Sorbus from Bosnia and Herzegovina are probably parallel to those in other diversity hotspots of this genus. The results represent a solid contribution to knowledge of the reproduction of Sorbus and will inform future investigations of the molecular and genetic mechanisms involved in triggering and regulating cytotype diversity and alteration of reproductive modes.
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Affiliation(s)
- Alma Hajrudinović
- Faculty of Forestry, University of Sarajevo, Zagrebačka 20, 71000 Sarajevo, Bosnia and Herzegovina
| | - Sonja Siljak-Yakovlev
- CNRS, Université Paris-Sud, AgroParisTech, UMR 8079, Ecologie, Systématique, Evolution, Bât. 360, 91450 Orsay, France and
| | - Spencer C Brown
- Pôle de Biologie Cellulaire, Imagif, Centre de Recherche de Gif (FRC3115), CNRS, Saclay Plant Sciences, 91198, Gif-sur-Yvette Cedex, France
| | - Fatima Pustahija
- Faculty of Forestry, University of Sarajevo, Zagrebačka 20, 71000 Sarajevo, Bosnia and Herzegovina
| | - Mickael Bourge
- Pôle de Biologie Cellulaire, Imagif, Centre de Recherche de Gif (FRC3115), CNRS, Saclay Plant Sciences, 91198, Gif-sur-Yvette Cedex, France
| | - Dalibor Ballian
- Faculty of Forestry, University of Sarajevo, Zagrebačka 20, 71000 Sarajevo, Bosnia and Herzegovina
| | - Faruk Bogunić
- Faculty of Forestry, University of Sarajevo, Zagrebačka 20, 71000 Sarajevo, Bosnia and Herzegovina,
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Prančl J, Kaplan Z, Trávníček P, Jarolímová V. Genome size as a key to evolutionary complex aquatic plants: polyploidy and hybridization in Callitriche (Plantaginaceae). PLoS One 2014; 9:e105997. [PMID: 25211149 PMCID: PMC4161354 DOI: 10.1371/journal.pone.0105997] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 07/26/2014] [Indexed: 01/31/2023] Open
Abstract
Despite their complex evolutionary histories, aquatic plants are highly underrepresented in contemporary biosystematic studies. Of them, the genus Callitriche is particularly interesting because of such evolutionary features as wide variation in chromosome numbers and pollination systems. However, taxonomic difficulties have prevented broader investigation of this genus. In this study we applied flow cytometry to Callitriche for the first time in order to gain an insight into evolutionary processes and genome size differentiation in the genus. Flow cytometry complemented by confirmation of chromosome counts was applied to an extensive dataset of 1077 Callitriche individuals from 495 localities in 11 European countries and the USA. Genome size was determined for 12 taxa. The results suggest that many important processes have interacted in the evolution of the genus, including polyploidization and hybridization. Incongruence between genome size and ploidy level, intraspecific variation in genome size, formation of autotriploid and hybridization between species with different pollination systems were also detected. Hybridization takes place particularly in the diploid-tetraploid complex C. cophocarpa-C. platycarpa, for which the triploid hybrids were frequently recorded in the area of co-occurrence of its parents. A hitherto unknown hybrid (probably C. hamulata × C. cophocarpa) with a unique chromosome number was discovered in the Czech Republic. However, hybridization occurs very rarely among most of the studied species. The main ecological preferences were also compared among the taxa collected. Although Callitriche taxa often grow in mixed populations, the ecological preferences of individual species are distinctly different in some cases. Anyway, flow cytometry is a very efficient method for taxonomic delimitation, determination and investigation of Callitriche species, and is even able to distinguish homoploid taxa and identify introduced species.
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Affiliation(s)
- Jan Prančl
- Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice, Czech Republic
- Department of Botany, Charles University, Praha, Czech Republic
| | - Zdeněk Kaplan
- Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice, Czech Republic
| | - Pavel Trávníček
- Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice, Czech Republic
- Department of Botany, Charles University, Praha, Czech Republic
| | - Vlasta Jarolímová
- Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice, Czech Republic
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25
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26
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Zarrei M, Stefanović S, Dickinson TA. Reticulate evolution in North American black-fruited hawthorns (Crataegus section Douglasia; Rosaceae): evidence from nuclear ITS2 and plastid sequences. ANNALS OF BOTANY 2014; 114:253-69. [PMID: 24984714 PMCID: PMC4111394 DOI: 10.1093/aob/mcu116] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Accepted: 05/07/2014] [Indexed: 05/19/2023]
Abstract
BACKGROUND AND AIMS The taxonomic complexity of Crataegus (hawthorn; Rosaceae, Maleae), especially in North America, has been attributed by some to hybridization in combination with gametophytic apomixis and polyploidization, whereas others have considered the roles of hybridization and apomixis to be minimal. Study of the chemical composition and therapeutic value of hawthorn extracts requires reproducible differentiation of entities that may be difficult to distinguish by morphology alone. This study sought to address this by using the nuclear ribosomal spacer region ITS2 as a supplementary DNA barcode; however, a lack of success prompted an investigation to discover why this locus gave unsatisfactory results. METHODS ITS2 was extensively cloned so as to document inter- and intraindividual variation in this locus, using hawthorns of western North America where the genus Crataegus is represented by only two widely divergent groups, the red-fruited section Coccineae and the black-fruited section Douglasia. Additional sequence data from selected loci on the plastid genome were obtained to enhance further the interpretation of the ITS2 results. KEY RESULTS In the ITS2 gene tree, ribotypes from western North American hawthorns are found in two clades. Ribotypes from diploid members of section Douglasia occur in one clade (with representatives of the east-Asian section Sanguineae). The other clade comprises those from diploid and polyploid members of section Coccineae. Both clades contribute ribotypes to polyploid Douglasia. Data from four plastid-derived intergenic spacers demonstrate the maternal parentage of these allopolyploids. CONCLUSIONS Repeated hybridization between species of section Douglasia and western North American members of section Coccineae involving the fertilization of unreduced female gametes explains the observed distribution of ribotypes and accounts for the phenetic intermediacy of many members of section Douglasia.
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Affiliation(s)
- M Zarrei
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto ON, Canada M5S 3B2 Department of Natural History, Royal Ontario Museum, 100 Queen's Park, Toronto ON, Canada M5S 2C6
| | - S Stefanović
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto ON, Canada M5S 3B2 Department of Biology, University of Toronto Mississauga, 3359 Mississauga Rd, Mississauga ON, Canada L5L 1C6
| | - T A Dickinson
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto ON, Canada M5S 3B2 Department of Natural History, Royal Ontario Museum, 100 Queen's Park, Toronto ON, Canada M5S 2C6
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27
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Burgess MB, Cushman KR, Doucette ET, Talent N, Frye CT, Campbell CS. Effects of apomixis and polyploidy on diversification and geographic distribution in Amelanchier (Rosaceae). AMERICAN JOURNAL OF BOTANY 2014; 101:1375-87. [PMID: 25156985 DOI: 10.3732/ajb.1400113] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
UNLABELLED • PREMISE OF THE STUDY Amelanchier polyploid apomicts differ from sexual diploids in their more complex diversification, greater species problems, and geographic distribution. To understand these differences, we investigated the occurrence of polyploidy and frequency of apomixis. This research helps clarify species delimitation in an evolutionarily complex genus.• METHODS We used flow cytometry to estimate genome size of 1355 plants. We estimated the frequency of apomixis from flow-cytometrically determined ploidy levels of embryo and endosperm and from a progeny study using RAPD markers. We explored relationships of triploids to other ploidy levels and of ploidy levels to latitude plus elevation.• KEY RESULTS Diploids (32% of sample) and tetraploids (62%) were widespread. Triploids (6%) mostly occurred in small numbers with diploids from two or more species or with diploids and tetraploids. Seeds from diploids were 2% apomictic, the first report of apomixis in Amelanchier diploids. Seeds from triploids were 75% apomictic. We documented potential triploid bridge and triploid block from unbalanced endosperm and low pollen viability. Seeds from tetraploids were 97% apomictic, and tetraploids often formed microspecies. We did not find strong evidence for geographical parthenogenesis in North American Amelanchier. Most currently recognized species contained multiple ploidy levels that were morphologically semicryptic.• CONCLUSIONS Documentation of numerous transitions from diploidy to polyploidy helps clarify diversification, geographic distribution, and the species problem in Amelanchier. Despite the infrequent occurrence of triploids, their retention of 25% sexuality and capacity for triploid bridge may be important steps between sexual diploids and predominantly apomictic tetraploids.
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Affiliation(s)
- Michael B Burgess
- Department of Biological Sciences, State University of New York, Plattsburgh, Plattsburgh, New York 12901 USA
| | - Kevin R Cushman
- School of Biology and Ecology, University of Maine, Orono, Maine 04469 USA
| | - Eric T Doucette
- School of Biology and Ecology, University of Maine, Orono, Maine 04469 USA
| | - Nadia Talent
- Royal Ontario Museum, Department of Natural History, 100 Queen's Park, Toronto, M5S 2C6, Canada
| | - Christopher T Frye
- Maryland Department of Natural Resources, Natural Heritage Program, 909 Wye Mills Road, Wye Mills, Maryland 21679 USA
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Soltis DE, Segovia-Salcedo MC, Jordon-Thaden I, Majure L, Miles NM, Mavrodiev EV, Mei W, Cortez MB, Soltis PS, Gitzendanner MA. Are polyploids really evolutionary dead-ends (again)? A critical reappraisal of Mayrose et al. (). THE NEW PHYTOLOGIST 2014; 202:1105-1117. [PMID: 24754325 DOI: 10.1111/nph.12756] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Affiliation(s)
- Douglas E Soltis
- Department of Biology, University of Florida, Gainesville, FL, 32611, USA
- Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA
- Genetics Institute, University of Florida, Gainesville, FL, 32610, USA
| | - María Claudia Segovia-Salcedo
- Department of Biology, University of Florida, Gainesville, FL, 32611, USA
- Grupo de Investigacíon Conservación de Bosques de Polylepis, Departamento de Ciencias de la Vida y de la Agricultura, Universidad de la Fuerzas Armadas - ESPE, Sangolquí, Ecuador
| | - Ingrid Jordon-Thaden
- Department of Biology, University of Florida, Gainesville, FL, 32611, USA
- University and Jepson Herbaria, University of California-Berkeley, Berkeley, CA, 94720, USA
| | - Lucas Majure
- Department of Biology, University of Florida, Gainesville, FL, 32611, USA
| | - Nicolas M Miles
- Department of Biology, University of Florida, Gainesville, FL, 32611, USA
| | - Evgeny V Mavrodiev
- Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA
| | - Wenbin Mei
- Genetics Institute, University of Florida, Gainesville, FL, 32610, USA
| | | | - Pamela S Soltis
- Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA
- Genetics Institute, University of Florida, Gainesville, FL, 32610, USA
| | - Matthew A Gitzendanner
- Department of Biology, University of Florida, Gainesville, FL, 32611, USA
- Genetics Institute, University of Florida, Gainesville, FL, 32610, USA
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Rich TCG, Green D, Houston L, Lepší M, Ludwig S, Pellicer J. BritishSorbus(Rosaceae): six new species, two hybrids and a new subgenus. ACTA ACUST UNITED AC 2014. [DOI: 10.1179/2042349714y.0000000036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Pellicer J, Kelly LJ, Leitch IJ, Zomlefer WB, Fay MF. A universe of dwarfs and giants: genome size and chromosome evolution in the monocot family Melanthiaceae. THE NEW PHYTOLOGIST 2014; 201:1484-1497. [PMID: 24299166 DOI: 10.1111/nph.12617] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 10/30/2013] [Indexed: 05/22/2023]
Abstract
• Since the occurrence of giant genomes in angiosperms is restricted to just a few lineages, identifying where shifts towards genome obesity have occurred is essential for understanding the evolutionary mechanisms triggering this process. • Genome sizes were assessed using flow cytometry in 79 species and new chromosome numbers were obtained. Phylogenetically based statistical methods were applied to infer ancestral character reconstructions of chromosome numbers and nuclear DNA contents. • Melanthiaceae are the most diverse family in terms of genome size, with C-values ranging more than 230-fold. Our data confirmed that giant genomes are restricted to tribe Parideae, with most extant species in the family characterized by small genomes. Ancestral genome size reconstruction revealed that the most recent common ancestor (MRCA) for the family had a relatively small genome (1C = 5.37 pg). Chromosome losses and polyploidy are recovered as the main evolutionary mechanisms generating chromosome number change. • Genome evolution in Melanthiaceae has been characterized by a trend towards genome size reduction, with just one episode of dramatic DNA accumulation in Parideae. Such extreme contrasting profiles of genome size evolution illustrate the key role of transposable elements and chromosome rearrangements in driving the evolution of plant genomes.
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Affiliation(s)
- Jaume Pellicer
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
| | - Laura J Kelly
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK
| | - Ilia J Leitch
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
| | - Wendy B Zomlefer
- Department of Plant Biology, 2502 Plant Sciences, University of Georgia, Athens, GA, 30602-7271, USA
| | - Michael F Fay
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
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Pellicer J, Kelly L, Magdalena C, Leitch I. Insights into the dynamics of genome size and chromosome evolution in the early diverging angiosperm lineage Nymphaeales (water lilies). Genome 2013; 56:437-49. [DOI: 10.1139/gen-2013-0039] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Nymphaeales are the most species-rich lineage of the earliest diverging angiosperms known as the ANA grade (Amborellales, Nymphaeales, Austrobaileyales), and they have received considerable attention from morphological, physiological, and ecological perspectives. Although phylogenetic relationships between these three lineages of angiosperms are mainly well resolved, insights at the whole genome level are still limited because of a dearth of information. To address this, genome sizes and chromosome numbers in 34 taxa, comprising 28 species were estimated and analysed together with previously published data to provide an overview of genome size and chromosome diversity in Nymphaeales. Overall, genome sizes were shown to vary 10-fold and chromosome numbers and ploidy levels ranged from 2n = 2x = 18 to 2n = 16x = ∼224. Distinct patterns of genome diversity were apparent, reflecting the differential incidence of polyploidy, changes in repetitive DNA content, and chromosome rearrangements within and between genera. Using model-based approaches, ancestral genome size and basic chromosome numbers were reconstructed to provide insights into the dynamics of genome size and chromosome number evolution. Finally, by combining additional data from Amborellales and Austrobaileyales, a comprehensive overview of genome sizes and chromosome numbers in these early diverging angiosperms is presented.
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Affiliation(s)
- J. Pellicer
- Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK
| | - L.J. Kelly
- Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK
- Queen Mary University of London, School of Biological and Chemical Science, London E1 4NS, UK
| | - C. Magdalena
- Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK
| | - I.J. Leitch
- Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK
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Ludwig S, Robertson A, Rich TCG, Djordjević M, Cerović R, Houston L, Harris SA, Hiscock SJ. Breeding systems, hybridization and continuing evolution in Avon Gorge Sorbus. ANNALS OF BOTANY 2013; 111:563-75. [PMID: 23408832 PMCID: PMC3605949 DOI: 10.1093/aob/mct013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 12/17/2012] [Indexed: 05/10/2023]
Abstract
BACKGROUND AND AIMS Interspecific hybridization and polyploidy are key processes in plant evolution and are responsible for ongoing genetic diversification in the genus Sorbus (Rosaceae). The Avon Gorge, Bristol, UK, is a world 'hotspot' for Sorbus diversity and home to diploid sexual species and polyploid apomictic species. This research investigated how mating system variation, hybridization and polyploidy interact to generate this biological diversity. METHODS Mating systems of diploid, triploid and tetraploid Sorbus taxa were analysed using pollen tube growth and seed set assays from controlled pollinations, and parent-offspring genotyping of progeny from open and manual pollinations. KEY RESULTS Diploid Sorbus are outcrossing and self-incompatible (SI). Triploid taxa are pseudogamous apomicts and genetically invariable, but because they also display self-incompatibility, apomictic seed set requires pollen from other Sorbus taxa - a phenomenon which offers direct opportunities for hybridization. In contrast tetraploid taxa are pseudogamous but self-compatible, so do not have the same obligate requirement for intertaxon pollination. CONCLUSIONS The mating inter-relationships among Avon Gorge Sorbus taxa are complex and are the driving force for hybridization and ongoing genetic diversification. In particular, the presence of self-incompatibility in triploid pseudogamous apomicts imposes a requirement for interspecific cross-pollination, thereby facilitating continuing diversification and evolution through rare sexual hybridization events. This is the first report of naturally occurring pseudogamous apomictic SI plant populations, and we suggest that interspecific pollination, in combination with a relaxed endosperm balance requirement, is the most likely route to the persistence of these populations. We propose that Avon Gorge Sorbus represents a model system for studying the establishment and persistence of SI apomicts in natural populations.
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Affiliation(s)
- Shanna Ludwig
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Ashley Robertson
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Timothy C. G. Rich
- Department of Biodiversity & Systematic Biology, National Museum of Wales, Cardiff, UK
| | | | | | - Libby Houston
- School of Biological Sciences, University of Bristol, Bristol, UK
| | | | - Simon J. Hiscock
- School of Biological Sciences, University of Bristol, Bristol, UK
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