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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; 111:e16291. [PMID: 38439133 DOI: 10.1002/ajb2.16291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [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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Hrabovský M, Kubalová S, Mičieta K, Ščevková J. Environmental impacts on intraspecific variation in Ambrosia artemisiifolia genome size in Slovakia, Central Europe. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:33960-33974. [PMID: 38693457 PMCID: PMC11136817 DOI: 10.1007/s11356-024-33410-x] [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: 06/08/2023] [Accepted: 04/16/2024] [Indexed: 05/03/2024]
Abstract
The quantity of DNA in angiosperms exhibits variation attributed to many external influences, such as environmental factors, geographical features, or stress factors, which exert constant selection pressure on organisms. Since invasive species possess adaptive capabilities to acclimate to novel environmental conditions, ragweed (Ambrosia artemisiifolia L.) was chosen as a subject for investigating their influence on genome size variation. Slovakia has diverse climatic conditions, suitable for testing the hypothesis that air temperature and precipitation, the main limiting factors of ragweed occurrence, would also have an impact on its genome size. Our results using flow cytometry confirmed this hypothesis and also found a significant association with geographical features such as latitude, altitude, and longitude. We can conclude that plants growing in colder environments farther from oceanic influences exhibit smaller DNA amounts, while optimal growth conditions result in a greater variability in genome size, reflecting the diminished effect of selection pressure.
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Affiliation(s)
- Michal Hrabovský
- Department of Botany, Faculty of Natural Sciences, Comenius University, Révová 39, 811 02, Bratislava, Slovakia.
| | - Silvia Kubalová
- Department of Botany, Faculty of Natural Sciences, Comenius University, Révová 39, 811 02, Bratislava, Slovakia
| | - Karol Mičieta
- Department of Botany, Faculty of Natural Sciences, Comenius University, Révová 39, 811 02, Bratislava, Slovakia
| | - Jana Ščevková
- Department of Botany, Faculty of Natural Sciences, Comenius University, Révová 39, 811 02, Bratislava, Slovakia
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3
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Tang SK, Lee PH, Liou WT, Lin CH, Huang YM, Kuo LY. Fern Spores-"Ready-to-Use" Standards for Plant Genome Size Estimation Using a Flow Cytometric Approach. PLANTS (BASEL, SWITZERLAND) 2022; 12:140. [PMID: 36616269 PMCID: PMC9824788 DOI: 10.3390/plants12010140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/29/2022] [Accepted: 12/15/2022] [Indexed: 06/17/2023]
Abstract
Spores and pollen of plants were used as flow cytometric materials to efficiently infer genome sizes. Given this advantage, they hold great potential for various flow cytometric applications, particularly as plant genome size standards. To develop such novel standards, we investigated conditions of pretreatment (bead vortex), buffer, and reliable genome sizes of three fern spore collections-Cibotium taiwanense "Kuo4395", Sphaeropteris lepifera "Tang0001", and Alsophila metteniana "Lee s.n.". Additionally, up to 30 year-old spore collections were obtained from herbarium specimens and from samples stored at 4 °C; their spore nuclei were extracted, and the quality and quantity of these nucleus extractions through storage ages were examined. Nuclear extractions with a longer bead vortex duration or lower spore/bead ratio generally resulted in a higher recovered quantity but a lower quality or purity. For each spore standard, the protocol optimization was determined by their performance in bead vortex conditions, and a 1C genome size was further inferred by linear regression (C. taiwanense "Kuo4395" = 5.058 pg; S. lepifera "Tang0001" = 7.117 pg; and A. metteniana "Lee s.n." = 19.379 pg). Spore nucleus quality and quantity are significantly negatively correlated with storage ages. Nuclear extractions of 10-year-old refrigerated spores remained qualified as a genome size standard; however, none of the herbarium spore collections fit such criteria. Our study is the first to develop and apply dried and refrigerated spores for genome size standards. These standards are ready to use, easy to manipulate, and feature long-term storage in comparison with traditionally used standards of fresh leaves.
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Affiliation(s)
- Sheng-Kai Tang
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu City 300, Taiwan
| | - Pei-Hsuan Lee
- Taiwan Forestry Research Institute, 53 Nan-Hai Road, Taipei City 100, Taiwan
| | - Wei-Ting Liou
- Experimental Forest, College of Bio-Resources and Agriculture, National Taiwan University, Nantou County 557, Taiwan
- Department of Life Sciences, National Chung Hsing University, Taichung City 402, Taiwan
| | - Chen-Hsiang Lin
- Taoyuan District Agricultural Research and Extension Station, Council of Agriculture, Executive Yuan, Taoyuan City 327, Taiwan
| | - Yao-Moan Huang
- Taiwan Forestry Research Institute, 53 Nan-Hai Road, Taipei City 100, Taiwan
| | - Li-Yaung Kuo
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu City 300, Taiwan
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4
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Martínez-Sagarra G, Castro S, Mota L, Loureiro J, Devesa JA. Genome Size, Chromosome Number and Morphological Data Reveal Unexpected Infraspecific Variability in Festuca (Poaceae). Genes (Basel) 2021; 12:genes12060906. [PMID: 34208200 PMCID: PMC8230830 DOI: 10.3390/genes12060906] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/08/2021] [Accepted: 06/09/2021] [Indexed: 01/12/2023] Open
Abstract
Polyploidy has played an important evolutionary role in the genus Festuca (Poaceae), and several ploidy levels (ranging from 2n = 2x = 14 to 2n = 12x = 84) have been detected to date. This study aimed to estimate the genome size and ploidy level of two subspecies belonging to the F. yvesii polyploid complex by flow cytometry and chromosome counting. The phenotypic variation of the cytotypes was also explored, based on herbarium material. The genome size of F. yvesii subsp. lagascae has been estimated for the first time. Nuclear 2C DNA content of F. yvesii subsp. summilusitana ranged from 21.44 to 31.91 pg, while that of F. yvesii subsp. lagascae was from 13.60 to 22.31 pg. We report the highest ploidy level detected for Festuca (2n = 14x = 98) and previously unknown cytotypes. A positive correlation between holoploid genome size and chromosome number counts shown herein was confirmed. The morphometric approach showed a slight trend towards an increase in the size of some organs consistent with the variation in the ploidy level. Differences in characters were usually significant only among the most extreme cytotypes of each subspecies, but, even in this case, the high overlapping ranges prevent their distinction.
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Affiliation(s)
- Gloria Martínez-Sagarra
- Department of Botany, Ecology and Plant Physiology, Rabanales Campus, University of Cordoba, 14071 Cordoba, Spain;
- Correspondence:
| | - Sílvia Castro
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal; (S.C.); (L.M.); (J.L.)
- Botanical Garden of the University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal
| | - Lucie Mota
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal; (S.C.); (L.M.); (J.L.)
| | - João Loureiro
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal; (S.C.); (L.M.); (J.L.)
| | - Juan A. Devesa
- Department of Botany, Ecology and Plant Physiology, Rabanales Campus, University of Cordoba, 14071 Cordoba, Spain;
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Šlenker M, Kantor A, Marhold K, Schmickl R, Mandáková T, Lysak MA, Perný M, Caboňová M, Slovák M, Zozomová-Lihová J. Allele Sorting as a Novel Approach to Resolving the Origin of Allotetraploids Using Hyb-Seq Data: A Case Study of the Balkan Mountain Endemic Cardamine barbaraeoides. FRONTIERS IN PLANT SCIENCE 2021; 12:659275. [PMID: 33995457 PMCID: PMC8115912 DOI: 10.3389/fpls.2021.659275] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/10/2021] [Indexed: 05/19/2023]
Abstract
Mountains of the Balkan Peninsula are significant biodiversity hotspots with great species richness and a large proportion of narrow endemics. Processes that have driven the evolution of the rich Balkan mountain flora, however, are still insufficiently explored and understood. Here we focus on a group of Cardamine (Brassicaceae) perennials growing in wet, mainly mountainous habitats. It comprises several Mediterranean endemics, including those restricted to the Balkan Peninsula. We used target enrichment with genome skimming (Hyb-Seq) to infer their phylogenetic relationships, and, along with genomic in situ hybridization (GISH), to resolve the origin of tetraploid Cardamine barbaraeoides endemic to the Southern Pindos Mts. (Greece). We also explored the challenges of phylogenomic analyses of polyploid species and developed a new approach of allele sorting into homeologs that allows identifying subgenomes inherited from different progenitors. We obtained a robust phylogenetic reconstruction for diploids based on 1,168 low-copy nuclear genes, which suggested both allopatric and ecological speciation events. In addition, cases of plastid-nuclear discordance, in agreement with divergent nuclear ribosomal DNA (nrDNA) copy variants in some species, indicated traces of interspecific gene flow. Our results also support biogeographic links between the Balkan and Anatolian-Caucasus regions and illustrate the contribution of the latter region to high Balkan biodiversity. An allopolyploid origin was inferred for C. barbaraeoides, which highlights the role of mountains in the Balkan Peninsula both as refugia and melting pots favoring species contacts and polyploid evolution in response to Pleistocene climate-induced range dynamics. Overall, our study demonstrates the importance of a thorough phylogenomic approach when studying the evolution of recently diverged species complexes affected by reticulation events at both diploid and polyploid levels. We emphasize the significance of retrieving allelic and homeologous variation from nuclear genes, as well as multiple nrDNA copy variants from genome skim data.
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Affiliation(s)
- Marek Šlenker
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Bratislava, Slovakia
- Department of Botany, Faculty of Science, Charles University, Prague, Czechia
| | - Adam Kantor
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Karol Marhold
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Bratislava, Slovakia
- Department of Botany, Faculty of Science, Charles University, Prague, Czechia
| | - Roswitha Schmickl
- Department of Botany, Faculty of Science, Charles University, Prague, Czechia
- Institute of Botany, The Czech Academy of Sciences, Průhonice, Czechia
| | - Terezie Mandáková
- Central European Institute of Technology, Masaryk University, Brno, Czechia
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czechia
| | - Martin A. Lysak
- Central European Institute of Technology, Masaryk University, Brno, Czechia
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czechia
| | | | - Michaela Caboňová
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Marek Slovák
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Bratislava, Slovakia
- Department of Botany, Faculty of Science, Charles University, Prague, Czechia
| | - Judita Zozomová-Lihová
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Bratislava, Slovakia
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Duchoslav M, Jandová M, Kobrlová L, Šafářová L, Brus J, Vojtěchová K. Intricate Distribution Patterns of Six Cytotypes of Allium oleraceum at a Continental Scale: Niche Expansion and Innovation Followed by Niche Contraction With Increasing Ploidy Level. FRONTIERS IN PLANT SCIENCE 2020; 11:591137. [PMID: 33362819 PMCID: PMC7755979 DOI: 10.3389/fpls.2020.591137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 11/06/2020] [Indexed: 05/23/2023]
Abstract
The establishment and success of polyploids are thought to often be facilitated by ecological niche differentiation from diploids. Unfortunately, most studies compared diploids and polyploids, ignoring variation in ploidy level in polyploids. To fill this gap, we performed a large-scale study of 11,163 samples from 1,283 populations of the polyploid perennial geophyte Allium oleraceum with reported mixed-ploidy populations, revealed distribution ranges of cytotypes, assessed their niches and explored the pattern of niche change with increasing ploidy level. Altogether, six ploidy levels (3x-8x) were identified. The most common were pentaploids (53.6%) followed by hexaploids (22.7%) and tetraploids (21.6%). Higher cytotype diversity was found at lower latitudes than at higher latitudes (>52° N), where only tetraploids and pentaploids occurred. We detected 17.4% of mixed-ploidy populations, usually as a combination of two, rarely of three, cytotypes. The majority of mixed-ploidy populations were found in zones of sympatry of the participating cytotypes, suggesting they have arisen through migration (secondary contact zone). Using coarse-grained variables (climate, soil), we found evidence of both niche expansion and innovation in tetraploids related to triploids, whereas higher ploidy levels showed almost zero niche expansion, but a trend of increased niche unfilling of tetraploids. Niche unfilling in higher ploidy levels was caused by a contraction of niche envelopes toward lower continentality of the climate and resulted in a gradual decrease of niche breadth and a gradual shift in niche optima. Field-recorded data indicated wide habitat breadth of tetraploids and pentaploids, but also a pattern of increasing synanthropy in higher ploidy levels. Wide niche breadth of tetra- and pentaploids might be related to their multiple origins from different environmental conditions, higher "age", and retained sexuality, which likely preserve their adaptive potential. In contrast, other cytotypes with narrower niches are mostly asexual, probably originating from a limited range of contrasting environments. Persistence of local ploidy mixtures could be enabled by the perenniality of A. oleraceum and its prevalence of vegetative reproduction, facilitating the establishment and decreasing exclusion of minority cytotype due to its reproductive costs. Vegetative reproduction might also significantly accelerate colonization of new areas, including recolonization of previously glaciated areas.
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Affiliation(s)
- Martin Duchoslav
- Plant Biosystematics and Ecology RG, Department of Botany, Faculty of Science, Palacký University, Olomouc, Czechia
| | - Michaela Jandová
- Plant Biosystematics and Ecology RG, Department of Botany, Faculty of Science, Palacký University, Olomouc, Czechia
- Institute of Botany, Czech Academy of Sciences, Pruhonice, Czechia
| | - Lucie Kobrlová
- Plant Biosystematics and Ecology RG, Department of Botany, Faculty of Science, Palacký University, Olomouc, Czechia
| | - Lenka Šafářová
- Plant Biosystematics and Ecology RG, Department of Botany, Faculty of Science, Palacký University, Olomouc, Czechia
| | - Jan Brus
- Department of Geoinformatics, Faculty of Science, Palacký University, Olomouc, Czechia
| | - Kateřina Vojtěchová
- Plant Biosystematics and Ecology RG, Department of Botany, Faculty of Science, Palacký University, Olomouc, Czechia
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Melichárková A, Španiel S, Marhold K, Hurdu BI, Drescher A, Zozomová-Lihová J. Diversification and independent polyploid origins in the disjunct species Alyssum repens from the Southeastern Alps and the Carpathians. AMERICAN JOURNAL OF BOTANY 2019; 106:1499-1518. [PMID: 31639199 DOI: 10.1002/ajb2.1370] [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: 05/24/2019] [Accepted: 08/30/2019] [Indexed: 05/20/2023]
Abstract
PREMISE Disjunct distributions have been commonly observed in mountain plant species and have stimulated phylogeographic and phylogenetic research. Here we studied Alyssum repens, a member of the polyploid species complex A. montanum-A. repens, which exhibits SE Alpine-Carpathian disjunctions with a large elevational span and consists of diploid and tetraploid populations. We aimed to investigate the species' genetic and cytotype structure in the context of its distribution patterns, to elucidate the polyploid origins and to propose an appropriate taxonomic treatment. METHODS We combined AFLP fingerprinting markers, sequence variation of the highly repetitive ITS region of rDNA and the low-copy DET1 nuclear gene, genome size, and morphometric data. RESULTS We identified four geographically structured genetic lineages. One consisted of diploid populations from the foothills of the Southeastern Alps and neighboring regions, and the three others were allopatric montane to alpine groups comprising diploids and tetraploids growing in the Southeastern Carpathians and the Apuseni Mts. in Romania. CONCLUSIONS We inferred a vicariance scenario associated with Quaternary climatic oscillations, accompanied by one auto- and two allopolyploidization events most likely involving a northern Balkan relative. Whereas genetic differentiation and allopatric distribution would favor the taxonomic splitting of this species, the genetic lineages largely lack morphological distinguishability, and their ecological, cytotype and genome size divergence is only partial. Even though we probably face here a case of incipient speciation, we propose to maintain the current taxonomic treatment of Alyssum repens as a single, albeit variable, species.
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Affiliation(s)
- Andrea Melichárková
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 23, Bratislava, Slovakia
| | - Stanislav Španiel
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 23, Bratislava, Slovakia
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, CZ-128 01, Prague, Czech Republic
| | - Karol Marhold
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 23, Bratislava, Slovakia
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, CZ-128 01, Prague, Czech Republic
| | - Bogdan-Iuliu Hurdu
- Institute of Biological Research, National Institute of Research and Development for Biological Sciences, 48 Republicii Street, 400015, Cluj-Napoca, Romania
| | - Anton Drescher
- Institut für Pflanzenwissenschaften der Universität Graz - Herbarium GZU, Holteigasse 6, A-8010, Graz, Austria
| | - Judita Zozomová-Lihová
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 23, Bratislava, Slovakia
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Šingliarová B, Zozomová-Lihová J, Mráz P. Polytopic origin and scale-dependent spatial segregation of cytotypes in primary diploid–autopolyploid contact zones ofPilosella rhodopea(Asteraceae). Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/bly199] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Barbora Šingliarová
- Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dúbravská cesta, Bratislava, Slovakia
| | - Judita Zozomová-Lihová
- Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dúbravská cesta, Bratislava, Slovakia
| | - Patrik Mráz
- Herbarium and Department of Botany, Charles University, Benátská,Prague, Czech Republic
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Dobeš C, Scheffknecht S, Fenko Y, Prohaska D, Sykora C, Hülber K. Asymmetric reproductive interference: The consequences of cross-pollination on reproductive success in sexual-apomictic populations of Potentilla puberula (Rosaceae). Ecol Evol 2017; 8:365-381. [PMID: 29321878 PMCID: PMC5756837 DOI: 10.1002/ece3.3684] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 10/03/2017] [Accepted: 11/08/2017] [Indexed: 11/16/2022] Open
Abstract
Apomixis evolves from a sexual background and usually is linked to polyploidization. Pseudogamous gametophytic apomicts, which require a fertilization to initiate seed development, of various ploidy levels frequently co‐occur with their lower‐ploid sexual ancestors, but the stability of such mixed populations is affected by reproductive interferences mediated by cross‐pollination. Thereby, reproductive success of crosses depends on the difference in ploidy levels of mating partners, that is, on tolerance of deviation from the balanced ratio of maternal versus paternal genomes. Quality of pollen can further affect reproductive success in intercytotype pollinations. Cross‐fertilization, however, can be avoided by selfing which may be induced upon pollination with mixtures of self‐ and cross‐pollen (i.e., mentor effects). We tested for reproductive compatibility of naturally co‐occurring tetraploid sexuals and penta‐ to octoploid apomicts in the rosaceous species Potentilla puberula by means of controlled crosses. We estimated the role of selfing as a crossing barrier and effects of self‐ and cross‐pollen quality as well as maternal: paternal genomic ratios in the endosperm on reproductive success. Cross‐fertilization of sexuals by apomicts was not blocked by selfing, and seed set was reduced in hetero‐ compared to homoploid crosses. Thereby, seed set was negatively related to deviations from balanced parental genomic ratios in the endosperm. In contrast, seed set in the apomictic cytotypes was not reduced in hetero‐ compared to homoploid crosses. Thus, apomictic cytotypes either avoided intercytotype cross‐fertilization through selfing, tolerated intercytotype cross‐fertilizations without negative effects on reproductive success, or even benefitted from higher pollen quality in intercytotype pollinations. Our experiment provides evidence for asymmetric reproductive interference, in favor of the apomicts, with significantly reduced seed set of sexuals in cytologically mixed populations, whereas seed set in apomicts was not affected. Incompleteness of crossing barriers further indicated at least partial losses of a parental genomic endosperm balance requirement.
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Affiliation(s)
- Christoph Dobeš
- Department of Forest Genetics Austrian Research Centre for Forests Vienna Austria
| | - Susanne Scheffknecht
- Department of Pharmacognosy and Pharmacobotany University of Vienna Vienna Austria
| | - Yulia Fenko
- Department of Pharmacognosy and Pharmacobotany University of Vienna Vienna Austria
| | - Dagmar Prohaska
- Department of Pharmacognosy and Pharmacobotany University of Vienna Vienna Austria
| | - Christina Sykora
- Department of Pharmacognosy and Pharmacobotany University of Vienna Vienna Austria
| | - Karl Hülber
- Division of Conservation Biology, Vegetation Ecology and Landscape Ecology Department of Botany and Biodiversity Research University of Vienna Vienna Austria.,Vienna Institute for Nature Conservation and Analyses Vienna Austria
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Štubňová E, Hodálová I, Kučera J, Mártonfiová L, Svitok M, Slovák M. Karyological patterns in the European endemic genus Soldanella L.: Absolute genome size variation uncorrelated with cytotype chromosome numbers. AMERICAN JOURNAL OF BOTANY 2017; 104:1241-1253. [PMID: 28790087 DOI: 10.3732/ajb.1700153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 05/23/2017] [Indexed: 06/07/2023]
Abstract
PREMISE OF THE STUDY Detailed knowledge about the karyological diversity of organisms undoubtedly represents one of the crucial steps toward a better understanding of their evolutionary trends and history. We investigated the cytotype and absolute genome size (AGS) patterns in the European mountain-dwelling genus Soldanella (Primulaceae) in light of its geographic distribution and ecological diversification. METHODS Our chromosome number survey was based on 34 newly determined and 125 previously published chromosome counts. AGS was estimated on the basis of propidium iodide (PI) flow cytometry (299 individuals, 110 populations). KEY RESULTS We confirmed the existence of two cytotypes with the same ploidy level, i.e., euploid 2n = 40 and dysploid 2n = 38. The overall infrageneric AGS variation ranged between 2.97 and 3.99 pg (25.6% variation). The 2n = 40 cytotype harbors a modest amount of continuous AGS variation. With regard to its distribution area and ecology, the cytotype is ubiquitous. By contrast, the 2n = 38 cytotype was detected only in six forest-dwelling taxa with AGS variation segregated into three discrete, geographically separated groups. The AGS variation of the 2n = 38 cytotype was strongly correlated with elevation and longitude. CONCLUSIONS Despite the apparent morphological and ecological variation, members of the genus Soldanella have not undergone any pronounced cytotype and AGS diversification during their evolutionary history. The lack of correlation between chromosome numbers and AGS indicates that the evolutionary mechanism behind the origin of the dysploid cytotype 2n = 38 was a chromosomal fusion.
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Affiliation(s)
- Eliška Štubňová
- Plant Science and Biodiversity Centre, Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84523 Bratislava, Slovak Republic
| | - Iva Hodálová
- Plant Science and Biodiversity Centre, Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84523 Bratislava, Slovak Republic
| | - Jaromír Kučera
- Plant Science and Biodiversity Centre, Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84523 Bratislava, Slovak Republic
| | - Lenka Mártonfiová
- Pavol Jozef Šafárik University, Botanical Garden, Mánesova 23, SK-04352 Košice, Slovak Republic
| | - Marek Svitok
- Technical University, Faculty of Ecology, T. G. Masaryka 2117/24, SK-96053 Zvolen, Slovak Republic
| | - Marek Slovák
- Plant Science and Biodiversity Centre, Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84523 Bratislava, Slovak Republic
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de Carvalho RF, Amaral-Silva PM, Spadeto MS, Nunes ACP, Carrijo TT, Carvalho CR, Clarindo WR. First karyotype description and nuclear 2C value for Myrsine (Primulaceae): comparing three species. COMPARATIVE CYTOGENETICS 2017; 11:163-177. [PMID: 28919956 PMCID: PMC5599700 DOI: 10.3897/compcytogen] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 01/21/2017] [Indexed: 06/07/2023]
Abstract
Cytogenetic studies in Primulaceae are mostly available for herbaceous species, and are focused on the chromosome number determination. An accurate karyotype characterization represents a starting point to know the morphometry and class of the chromosomes. Comparison among species within Myrsine, associating these data with the nuclear 2C value, can show changes that led the karyotype evolution. Here, we studied three Myrsine species [Myrsine coriacea (Swartz, 1788) Brown ex Roemer et Schultes, 1819, Myrsine umbellata Martius, 1841 and Myrsine parvifolia Candolle, 1841] that show different abilities to occupy the varied types of vegetation within the Brazilian Atlantic Forest. Cytogenetic characterization showed some individuals with 2n = 45 chromosomes for Myrsine parvifolia and Myrsine coriacea, with most individuals of the three species having 2n = 46. The first karyograms for Myrsine were assembled and presented morphologically identical and distinct chromosome pairs. In addition, differences in the mean 2C nuclear value and chromosome morphometry were found. Therefore, the first description of the Myrsine karyotype has been presented, as well as the nuclear 2C value. The procedures can be applied to other Myrsine species for future investigations in order to better understand its effects on the differential spatial occupation abilities shown by the species in Brazilian Atlantic Forest.
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Affiliation(s)
- Renata Flávia de Carvalho
- Laboratório de Citogenética, Departamento de Biologia, Centro de Ciências
Agrárias, Universidade Federal do Espírito Santo, 29.500-000 Alegre (ES),
Brazil
| | - Paulo Marcos Amaral-Silva
- Laboratório de Citogenética, Departamento de Biologia, Centro de Ciências
Agrárias, Universidade Federal do Espírito Santo, 29.500-000 Alegre (ES),
Brazil
| | - Micheli Sossai Spadeto
- Laboratório de Citogenética, Departamento de Biologia, Centro de Ciências
Agrárias, Universidade Federal do Espírito Santo, 29.500-000 Alegre (ES),
Brazil
| | - Andrei Caíque Pires Nunes
- Laboratório de Biometria, Departamento de Biologia Geral, Universidade Federal de
Viçosa, 36.570-000 Viçosa (MG), Brazil
| | - Tatiana Tavares Carrijo
- Laboratório de Botânica, Departamento de Biologia, Centro de Ciências Agrárias,
Universidade Federal do Espírito Santo, 29.500-000 Alegre (ES), Brazil
| | - Carlos Roberto Carvalho
- Laboratório de Citogenética e Citometria, Departamento de Biologia Geral, Centro
de Ciências Biológicas e da Saúde, Universidade Federal de Viçosa, 36.570-000 Viçosa (MG),
Brazil
| | - Wellington Ronildo Clarindo
- Laboratório de Citogenética, Departamento de Biologia, Centro de Ciências
Agrárias, Universidade Federal do Espírito Santo, 29.500-000 Alegre (ES),
Brazil
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12
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Olšavská K, Slovák M, Marhold K, Štubňová E, Kučera J. On the origins of Balkan endemics: the complex evolutionary history of the Cyanus napulifer group (Asteraceae). ANNALS OF BOTANY 2016; 118:1071-1088. [PMID: 27443297 PMCID: PMC5091721 DOI: 10.1093/aob/mcw142] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 03/02/2016] [Accepted: 06/03/2016] [Indexed: 05/29/2023]
Abstract
BACKGROUND AND AIMS The Balkan Peninsula is one of the most important centres of plant diversity in Europe. Here we aim to fill the gap in the current knowledge of the evolutionary processes and factors modelling this astonishing biological richness by applying multiple approaches to the Cyanus napulifer group. METHODS To reconstruct the mode of diversification within the C. napulifer group and to uncover its relationships with potential relatives with x = 10 from Europe and Northern Africa, we examined variation in genetic markers (amplified fragment length polymorphisms [AFLPs]; 460 individuals), relative DNA content (4',6-diamidino-2-phenylindole [DAPI] flow cytometry, 330 individuals) and morphology (multivariate morphometrics, 40 morphological characters, 710 individuals). To elucidate its evolutionary history, we analysed chloroplast DNA (cpDNA) sequences of the genus Cyanus deposited in the GenBank database. KEY RESULTS The AFLPs revealed a suite of closely related entities with variable levels of differentiation. The C. napulifer group formed a genetically well-defined unit. Samples outside the group formed strongly diversified and mostly species-specific genetic lineages with no further geographical patterns, often characterized also by a different DNA content. AFLP analysis of the C. napulifer group revealed extensive radiation and split it into nine allopatric (sub)lineages with varying degrees of congruence among genetic, DNA-content and morphological patterns. Genetic admixture was usually detected in contact zones between genetic lineages. Plastid data indicated extensive maintenance of ancestral variation across Cyanus perennials. CONCLUSION The C. napulifer group is an example of a rapidly and recently diversified plant group whose genetic lineages have evolved in spatio-temporal isolation on the topographically complex Balkan Peninsula. Adaptive radiation, accompanied in some cases by long-term isolation and hybridization, has contributed to the formation of this species complex and its mosaic pattern.
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Affiliation(s)
- Katarína Olšavská
- Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84523 Bratislava, Slovakia
| | - Marek Slovák
- Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84523 Bratislava, Slovakia
| | - Karol Marhold
- Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84523 Bratislava, Slovakia Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 01 Praha 2, Czech Republic
| | - Eliška Štubňová
- Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84523 Bratislava, Slovakia
| | - Jaromír Kučera
- Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84523 Bratislava, Slovakia
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13
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Boutte J, Ferreira de Carvalho J, Rousseau-Gueutin M, Poulain J, Da Silva C, Wincker P, Ainouche M, Salmon A. Reference Transcriptomes and Detection of Duplicated Copies in Hexaploid and Allododecaploid Spartina Species (Poaceae). Genome Biol Evol 2016; 8:3030-3044. [PMID: 27614235 PMCID: PMC5633685 DOI: 10.1093/gbe/evw209] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2016] [Indexed: 01/19/2023] Open
Abstract
In this study, we report the assembly and annotation of five reference transcriptomes for the European hexaploid Spartina species (S. maritima, S. alterniflora and their homoploid hybrids S. x townsendii and S. x neyrautii) and the allododecaploid invasive species S. anglica These transcriptomes were constructed from various leaf and root cDNA libraries that were sequenced using both Roche-454 and Illumina technologies. Considering the high ploidy levels of the Spartina genomes under study, and considering the absence of diploid reference genome and the need of an appropriate analytical strategy, we developed generic bioinformatics tools to (1) detect different haplotypes of each gene within each species and (2) assign a parental origin to haplotypes detected in the hexaploid hybrids and the neo-allopolyploid. The approach described here allows the detection of putative homeologs from sets of short reads. Synonymous substitution rate (KS) comparisons between haplotypes from the hexaploid species revealed the presence of one KS peak (likely resulting from the tetraploid duplication event). The procedure developed in this study can be applied for future differential gene expression or genomics experiments to study the fate of duplicated genes in the invasive allododecaploid S. anglica.
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Affiliation(s)
- Julien Boutte
- UMR CNRS 6553 Ecobio, OSUR (Observatoire des Sciences de l'Univers de Rennes), University of Rennes 1, Rennes Cedex, France
| | - Julie Ferreira de Carvalho
- UMR CNRS 6553 Ecobio, OSUR (Observatoire des Sciences de l'Univers de Rennes), University of Rennes 1, Rennes Cedex, France
| | - Mathieu Rousseau-Gueutin
- UMR CNRS 6553 Ecobio, OSUR (Observatoire des Sciences de l'Univers de Rennes), University of Rennes 1, Rennes Cedex, France UMR Institut de Génétique, Environnement et Protection des Plantes, Institut National de la Recherche Agronomique, Le Rheu Cedex, France
| | | | | | | | - Malika Ainouche
- UMR CNRS 6553 Ecobio, OSUR (Observatoire des Sciences de l'Univers de Rennes), University of Rennes 1, Rennes Cedex, France
| | - Armel Salmon
- UMR CNRS 6553 Ecobio, OSUR (Observatoire des Sciences de l'Univers de Rennes), University of Rennes 1, Rennes Cedex, France
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14
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Nuclear DNA content in Miscanthus sp. and the geographical variation pattern in Miscanthus lutarioriparius. Sci Rep 2016; 6:34342. [PMID: 27698438 PMCID: PMC5048105 DOI: 10.1038/srep34342] [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: 02/25/2016] [Accepted: 09/05/2016] [Indexed: 11/08/2022] Open
Abstract
The genome sizes of five Miscanthus species, including 79 accessions of M. lutarioriparius, 8 of M. floridulus, 6 of M. sacchariflorus, 7 of M. sinensis, and 4 of M. × giganteus were examined using flow cytometry. The overall average nuclear DNA content were 4.256 ± 0.6 pg/2C in M. lutarioriparius, 5.175 ± 0.3 pg/2C in M. floridulus, 3.956 ± 0.2 pg/2C in M. sacchariflorus, 5.272 ± 0.2 pg/2C in M. sinensis, and 6.932 ± 0.1 pg/2C in M. × giganteus. Interspecific variation was found at the diploid level, suggesting that DNA content might be a parameter that can be used to differentiate the species. Tetraploid populations were found in M. lutarioriparius, M. sacchariflorus, and M. sinensis, and their DNA content were 8.34 ± 1.2, 8.52, and 8.355 pg, respectively. The association between the DNA content of M. lutarioriparius, collected from representative ranges across the Yangtze River, and its geographic distribution was statistically analyzed. A consistent pattern of DNA content variation in 79 M. lutarioriparius accessions across its entire geographic range was found in this study. Along the Yangtze River, the DNA content of M. lutarioriparius tended to increase from the upstream to the downstream areas, and almost all tetraploids gathered in the upstream area extended to coastal regions.
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Amaral-Silva PM, Clarindo WR, Carrijo TT, Carvalho CR, Praça-Fontes MM. The contribution of cytogenetics and flow cytometry for understanding the karyotype evolution in three Dorstenia (Linnaeus, 1753) species (Moraceae). COMPARATIVE CYTOGENETICS 2016; 10:97-108. [PMID: 27186340 PMCID: PMC4856928 DOI: 10.3897/compcytogen.v10i1.6719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 11/18/2016] [Indexed: 06/05/2023]
Abstract
Chromosome morphometry and nuclear DNA content are useful data for cytotaxonomy and for understanding the evolutionary history of different taxa. However, the chromosome number is the only karyotype aspect reported for the species of Dorstenia so far. In this study, the nuclear genome size of Dorstenia arifolia (Lamarck, 1786), Dorstenia bonijesu (Carauta & C. Valente, 1983) and Dorstenia elata (Hooker, 1840) was evaluated and their karyotype morphometry accomplished, with the aim of verifying the potential of those parameters to understand evolutionary issues. Mean nuclear 2C value ranged from 2C = 3.49 picograms (pg) for Dorstenia elata to 2C = 5.47 pg for Dorstenia arifolia, a variation of ± 1.98 pg. Even though showing a marked difference in 2C value, the three species exhibited the same 2n = 32. Corroborating the flow cytometry data, differences in chromosome morphology were found among the karyotypes of the species investigated. Based on this and the only phylogeny proposed for Dorstenia thus far, structural rearrangements are related to the karyotype variations among the three species. Besides, the karyological analysis suggests a polyploid origin of the Dorstenia species studied here.
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Affiliation(s)
- Paulo Marcos Amaral-Silva
- Laboratório de Citogenética, Departamento de Biologia, Centro de Ciências Agrárias, Universidade Federal do Espírito Santo. CEP: 29.500-000 Alegre – ES, Brazil
| | - Wellington Ronildo Clarindo
- Laboratório de Citogenética, Departamento de Biologia, Centro de Ciências Agrárias, Universidade Federal do Espírito Santo. CEP: 29.500-000 Alegre – ES, Brazil
| | - Tatiana Tavares Carrijo
- Laboratório de Botânica, Departamento de Biologia, Centro de Ciências Agrárias, Universidade Federal do Espírito Santo. CEP: 29.500-000 Alegre – ES, Brazil
| | - Carlos Roberto Carvalho
- Laboratório de Citogenética e Citometria, Departamento de Biologia Geral, Centro de Ciências Biológicas e da Saúde, Universidade Federal de Viçosa. CEP: 36.570-000 Viçosa – MG, Brazil
| | - Milene Miranda Praça-Fontes
- Laboratório de Citogenética, Departamento de Biologia, Centro de Ciências Agrárias, Universidade Federal do Espírito Santo. CEP: 29.500-000 Alegre – ES, Brazil
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16
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Etterson JR, Toczydlowski RH, Winkler KJ, Kirschbaum JA, McAulay TS. Solidago altissima differs with respect to ploidy frequency and clinal variation across the prairie-forest biome border in Minnesota. AMERICAN JOURNAL OF BOTANY 2016; 103:22-32. [PMID: 26507110 DOI: 10.3732/ajb.1500146] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 06/30/2015] [Indexed: 06/05/2023]
Abstract
PREMISE OF THE STUDY Although our awareness of ploidy diversity has expanded with the application of flow cytometry, we still know little about the extent to which cytotypes within mixed-ploidy populations are genetically differentiated across environmental gradients. METHODS To address this issue, we reared 14 populations of Solidago altissima spanning the prairie-forest ecotone in Minnesota in a common garden with a watering treatment. We assessed ploidy frequencies and measured survival, flowering phenology, and plant architectural traits for 4 years. KEY RESULTS All populations harbored multiple cytotypes; prairie populations were dominated by tetraploids, forest populations by hexaploids. Diploids and polyploids differed significantly for 84% of the traits. Beyond average differences, the slope of trait values covaried with latitude and longitude, but this relationship was stronger for diploids than the other two polyploid cytotypes as indicated by numerous ploidy × latitude and ploidy × longitude interactions. For example, the timing of flowering of the cytotypes overlapped in populations sampled from the northeastern hemiboreal forest but differed significantly between cytotypes sampled from populations in the southwestern prairie. The watering treatments had weak effects, and there were no ploidy differences for phenotypic plasticity. CONCLUSIONS Our data show that diploids have diverged genetically to a greater extent than polyploids along the environmental clines sampled in this study. Moreover, different environments favor phenotypic convergence over divergence among cytotypes for some traits. Differences in ploidy frequency and phenotypic divergence among cytotypes across gradients of temperature and precipitation are important considerations for restoration in an age of climate change.
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Affiliation(s)
- Julie R Etterson
- Department of Biology, University of Minnesota Duluth, 207A Swenson Science Building, Duluth, Minnesota 55812 USA
| | - Rachel H Toczydlowski
- Department of Biology, University of Minnesota Duluth, 207A Swenson Science Building, Duluth, Minnesota 55812 USA
| | - Katharine J Winkler
- Department of Biology, University of Minnesota Duluth, 207A Swenson Science Building, Duluth, Minnesota 55812 USA
| | - Jessica A Kirschbaum
- Department of Biology, University of Minnesota Duluth, 207A Swenson Science Building, Duluth, Minnesota 55812 USA
| | - Tim S McAulay
- Department of Biology, University of Minnesota Duluth, 207A Swenson Science Building, Duluth, Minnesota 55812 USA
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Zozomová-Lihová J, Malánová-Krásná I, Vít P, Urfus T, Senko D, Svitok M, Kempa M, Marhold K. Cytotype distribution patterns, ecological differentiation, and genetic structure in a diploid-tetraploid contact zone of Cardamine amara. AMERICAN JOURNAL OF BOTANY 2015; 102:1380-95. [PMID: 26290560 DOI: 10.3732/ajb.1500052] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 07/16/2015] [Indexed: 05/20/2023]
Abstract
UNLABELLED • PREMISE OF THE STUDY Contact zones between diploids and their autopolyploid descendants represent a unique evolutionary venue for studying polyploid establishment, cytotype coexistence, and interactions. Here, we examine cytotype coexistence in a diploid-tetraploid contact zone of a perennial herb, Cardamine amara, located north of the Alps by assessing cytotype spatial patterns, ecological divergence, and genetic variation and structure.• METHODS Flow cytometry was applied to screen DNA ploidy levels in 302 populations (3296 individuals) and the genetic variation of a selection of 25 populations was examined using microsatellite and AFLP markers. Environmental (landscape and climatic) data were analyzed to assess ecological differentiation between the cytotypes.• KEY RESULTS A parapatric distribution of the cytotypes with a relatively wide (over 100 km in some regions) secondary contact zone was identified. Mixed-ploidy populations, documented for the first time in this species, as well as triploid individuals were found along the diploid-tetraploid borderline. Different climatic requirements of the two main cytotypes were revealed, mirrored in their altitudinal separation. The tetraploids were genetically differentiated from both the diploids and the modeled, in silico autotetraploid genotypes, in accordance with the assumed polyploid origin and spread linked to past glaciations, and largely independent evolution in allopatry.• CONCLUSIONS The observed spatial and genetic patterns likely reflect the evolutionary and colonization history of the two cytotypes and have been maintained by multiple factors such as ecological divergence, limited gene flow between the cytotypes, and the restricted dispersal capacity.
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Affiliation(s)
- Judita Zozomová-Lihová
- Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 23 Bratislava, Slovak Republic
| | | | - Petr Vít
- Department of Botany, Faculty of Sciences, Charles University, Benátská 2, CZ-128 01 Praha, Czech Republic Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43 Průhonice, Czech Republic
| | - Tomáš Urfus
- Department of Botany, Faculty of Sciences, Charles University, Benátská 2, CZ-128 01 Praha, Czech Republic Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43 Průhonice, Czech Republic
| | - Dušan Senko
- Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 23 Bratislava, Slovak Republic
| | - Marek Svitok
- Faculty of Ecology and Environmental Sciences, Technical University in Zvolen, T. G. Masaryka 24, SK-960 53 Zvolen, Slovak Republic Eawag Swiss Federal Institute of Aquatic Science and Technology, Department of Aquatic Ecology, Centre of Ecology, Evolution and Biogeochemistry, Seestrasse 79, CH-6047 Kastanienbaum, Switzerland
| | - Matúš Kempa
- Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 23 Bratislava, Slovak Republic
| | - Karol Marhold
- Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 23 Bratislava, Slovak Republic Department of Botany, Faculty of Sciences, Charles University, Benátská 2, CZ-128 01 Praha, Czech Republic
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18
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Frajman B, Rešetnik I, Weiss-Schneeweiss H, Ehrendorfer F, Schönswetter P. Cytotype diversity and genome size variation in Knautia (Caprifoliaceae, Dipsacoideae). BMC Evol Biol 2015; 15:140. [PMID: 26182989 PMCID: PMC4504173 DOI: 10.1186/s12862-015-0425-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 06/26/2015] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Polyploidisation is one of the most important mechanisms in the evolution of angiosperms. As in many other genera, formation of polyploids has significantly contributed to diversification and radiation of Knautia (Caprifoliaceae, Dipsacoideae). Comprehensive studies of fine- and broad-scale patterns of ploidy and genome size (GS) variation are, however, still limited to relatively few genera and little is known about the geographic distribution of ploidy levels within these genera. Here, we explore ploidy and GS variation in Knautia based on a near-complete taxonomic and comprehensive geographic sampling. RESULTS Genome size is a reliable indicator of ploidy level in Knautia, even if monoploid genome downsizing is observed in the polyploid cytotypes. Twenty-four species studied are diploid, 16 tetraploid and two hexaploid, whereas ten species possess two, and two species possess three ploidy levels. Di- and tetraploids are distributed across most of the distribution area of Knautia, while hexaploids were sampled in the Balkan and Iberian Peninsulas and the Alps. CONCLUSIONS We show that the frequency of polyploidisation is unevenly distributed in Knautia both in a geographic and phylogenetic context. Monoploid GS varies considerably among three evolutionary lineages (sections) of Knautia, but also within sections Trichera and Tricheroides, as well as within some of the species. Although the exact causes of this variation remain elusive, we demonstrate that monoploid GS increases significantly towards the limits of the genus' distribution.
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Affiliation(s)
- Božo Frajman
- Institute of Botany, University of Innsbruck, Sternwartestraße 15, A-6020, Innsbruck, Austria
| | - Ivana Rešetnik
- Faculty of Science, University of Zagreb, Marulićev trg 20/II, HR-10000, Zagreb, Croatia
| | - Hanna Weiss-Schneeweiss
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030, Vienna, Austria.
| | - Friedrich Ehrendorfer
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030, Vienna, Austria
| | - Peter Schönswetter
- Institute of Botany, University of Innsbruck, Sternwartestraße 15, A-6020, Innsbruck, Austria
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Kolář F, Lučanová M, Záveská E, Fuxová G, Mandáková T, Španiel S, Senko D, Svitok M, Kolník M, Gudžinskas Z, Marhold K. Ecological segregation does not drive the intricate parapatric distribution of diploid and tetraploid cytotypes of theArabidopsis arenosagroup (Brassicaceae). Biol J Linn Soc Lond 2015. [DOI: 10.1111/bij.12479] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Filip Kolář
- Department of Botany; Faculty of Science; Charles University in Prague; Benátská 2 CZ-128 01 Prague Czech Republic
- Institute of Botany; Academy of Sciences of the Czech Republic; Zámek 1 CZ-252 43 Průhonice Czech Republic
| | - Magdalena Lučanová
- Institute of Botany; Academy of Sciences of the Czech Republic; Zámek 1 CZ-252 43 Průhonice Czech Republic
- Department of Botany; Faculty of Science; Charles University in Prague; Benátská 2 CZ-128 01 Prague Czech Republic
| | - Eliška Záveská
- Department of Botany; Faculty of Science; Charles University in Prague; Benátská 2 CZ-128 01 Prague Czech Republic
| | - Gabriela Fuxová
- Department of Botany; Faculty of Science; Charles University in Prague; Benátská 2 CZ-128 01 Prague Czech Republic
| | - Terezie Mandáková
- Plant Cytogenomics Research Group; Central European Institute of Technology (CEITEC); Masaryk University; Kamenice 5 CZ-62500 Brno Czech Republic
| | - Stanislav Španiel
- Department of Botany; Faculty of Science; Charles University in Prague; Benátská 2 CZ-128 01 Prague Czech Republic
| | - Dušan Senko
- Institute of Botany; Slovak Academy of Sciences; Dúbravská cesta 9 SK-845 23 Bratislava Slovak Republic
| | - Marek Svitok
- Department of Biology and General Ecology; Faculty of Ecology and Environmental Sciences; Technical University in Zvolen; T. G. Masaryka 24 SK-960 53 Zvolen Slovak Republic
- Eawag Swiss Federal Institute of Aquatic Science and Technology; Department of Aquatic Ecology, Centre of Ecology; Evolution and Biogeochemistry; Seestrasse 79 CH-6047 Kastanienbaum Switzerland
| | - Martin Kolník
- Tematínska 4 SK-91501 Nové Mesto nad Váhom Slovak Republic
| | - Zigmantas Gudžinskas
- Nature Research Centre; Institute of Botany; Laboratory of Flora and Geobotany; Žaliųjų Ežerų Str. 49 LT-08406 Vilnius Lithuania
| | - Karol Marhold
- Department of Botany; Faculty of Science; Charles University in Prague; Benátská 2 CZ-128 01 Prague Czech Republic
- Institute of Botany; Slovak Academy of Sciences; Dúbravská cesta 9 SK-845 23 Bratislava Slovak Republic
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20
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Wolf DE, Steets JA, Houliston GJ, Takebayashi N. Genome size variation and evolution in allotetraploid Arabidopsis kamchatica and its parents, Arabidopsis lyrata and Arabidopsis halleri. AOB PLANTS 2014; 6:plu025. [PMID: 24887004 PMCID: PMC4076644 DOI: 10.1093/aobpla/plu025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Polyploidization and subsequent changes in genome size are fundamental processes in evolution and diversification. Little is currently known about the extent of genome size variation within taxa and the evolutionary forces acting on this variation. Arabidopsis kamchatica has been reported to contain both diploid and tetraploid individuals. The aim of this study was to determine the genome size of A. kamchatica, whether there is variation in ploidy and/or genome size in A. kamchatica and to study how genome size has evolved. We used propidium iodide flow cytometry to measure 2C DNA content of 73 plants from 25 geographically diverse populations of the putative allotetraploid A. kamchatica and its parents, Arabidopsis lyrata and Arabidopsis halleri. All A. kamchatica plants appear to be tetraploids. The mean 2C DNA content of A. kamchatica was 1.034 pg (1011 Mbp), which is slightly smaller than the sum of its diploid parents (A. lyrata: 0.502 pg; A. halleri: 0.571 pg). Arabidopsis kamchatica appears to have lost ∼37.594 Mbp (3.6 %) of DNA from its 2C genome. Tetraploid A. lyrata from Germany and Austria appears to have lost ∼70.366 Mbp (7.2 %) of DNA from the 2C genome, possibly due to hybridization with A. arenosa, which has a smaller genome than A. lyrata. We did find genome size differences among A. kamchatica populations, which varied up to 7 %. Arabidopsis kamchatica ssp. kawasakiana from Japan appears to have a slightly larger genome than A. kamchatica ssp. kamchatica from North America, perhaps due to multiple allopolyploid origins or hybridization with A. halleri. However, the among-population coefficient of variation in 2C DNA content is lower in A. kamchatica than in other Arabidopsis taxa. Due to its close relationship to A. thaliana, A. kamchatica has the potential to be very useful in the study of polyploidy and genome evolution.
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Affiliation(s)
- Diana E Wolf
- Department of Biology and Wildlife, Institute of Arctic Biology, University of Alaska Fairbanks, 311 Irving I, Fairbanks, AK 99775-7000, USA
| | - Janette A Steets
- Department of Biology and Wildlife, Institute of Arctic Biology, University of Alaska Fairbanks, 311 Irving I, Fairbanks, AK 99775-7000, USA Present Address: Department of Botany, Oklahoma State University, 301 Physical Sciences, Stillwater, OK 74078-3013, USA
| | - Gary J Houliston
- Department of Biology and Wildlife, Institute of Arctic Biology, University of Alaska Fairbanks, 311 Irving I, Fairbanks, AK 99775-7000, USA Present Address: Landcare Research, Gerald St, Lincoln 7608, New Zealand
| | - Naoki Takebayashi
- Department of Biology and Wildlife, Institute of Arctic Biology, University of Alaska Fairbanks, 311 Irving I, Fairbanks, AK 99775-7000, USA
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Zozomová-Lihová J, Krak K, Mandáková T, Shimizu KK, Španiel S, Vít P, Lysak MA. Multiple hybridization events in Cardamine (Brassicaceae) during the last 150 years: revisiting a textbook example of neoallopolyploidy. ANNALS OF BOTANY 2014; 113:817-30. [PMID: 24577071 PMCID: PMC3962249 DOI: 10.1093/aob/mcu012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Recently formed allopolyploid species represent excellent subjects for exploring early stages of polyploid evolution. The hexaploid Cardamine schulzii was regarded as one of the few nascent allopolyploid species formed within the past ∼150 years that presumably arose by autopolyploidization of a triploid hybrid, C. × insueta; however, the most recent investigations have shown that it is a trigenomic hybrid. The aims of this study were to explore the efficiency of progenitor-specific microsatellite markers in detecting the hybrid origins and genome composition of these two allopolyploids, to estimate the frequency of polyploid formation events, and to outline their evolutionary potential for long-term persistence and speciation. METHODS Flow-cytometric ploidy-level screening and genotyping by progenitor-specific microsatellite markers (20 microsatellite loci) were carried out on samples focused on hybridizing populations at Urnerboden, Switzerland, but also including comparative material of the parental species from other sites in the Alps and more distant areas. KEY RESULTS It was confirmed that hybridization between the diploids C. amara and C. rivularis auct. gave rise to triploid C. × insueta, and it is inferred that this has occurred repeatedly. Evidence is provided that C. schulzii comprises three parental genomes and supports its origin from hybridization events between C. × insueta and the locally co-occurring hypotetraploid C. pratensis, leading to two cytotypes of C. schulzii: hypopentaploid and hypohexaploid. Each cytotype of C. schulzii is genetically uniform, suggesting their single origins. CONCLUSIONS Persistence of C. schulzii has presumably been achieved only by perennial growth and clonal reproduction. This contrasts with C. × insueta, in which multiple origins and occasional sexual reproduction have generated sufficient genetic variation for long-term survival and evolutionary success. This study illustrates a complex case of recurrent hybridization and polyploidization events, and highlights the role of triploids that promoted the origin of trigenomic hybrids.
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Affiliation(s)
- Judita Zozomová-Lihová
- Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 23 Bratislava, Slovak Republic
- For correspondence. E-mail
| | - Karol Krak
- Institute of Botany, Academy of Sciences of the Czech Republic, Zámek 1, CZ-252 43 Průhonice, Czech Republic
| | - Terezie Mandáková
- Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic
| | - Kentaro K. Shimizu
- Institute of Evolutionary Biology and Environmental Studies, University of Zürich, Switzerland
| | - Stanislav Španiel
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 01 Praha, Czech Republic
| | - Petr Vít
- Institute of Botany, Academy of Sciences of the Czech Republic, Zámek 1, CZ-252 43 Průhonice, Czech Republic
| | - Martin A. Lysak
- Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic
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Weiss-Schneeweiss H, Emadzade K, Jang TS, Schneeweiss G. Evolutionary consequences, constraints and potential of polyploidy in plants. Cytogenet Genome Res 2013; 140:137-50. [PMID: 23796571 PMCID: PMC3859924 DOI: 10.1159/000351727] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Polyploidy, the possession of more than 2 complete genomes, is a major force in plant evolution known to affect the genetic and genomic constitution and the phenotype of an organism, which will have consequences for its ecology and geography as well as for lineage diversification and speciation. In this review, we discuss phylogenetic patterns in the incidence of polyploidy including possible underlying causes, the role of polyploidy for diversification, the effects of polyploidy on geographical and ecological patterns, and putative underlying mechanisms as well as chromosome evolution and evolution of repetitive DNA following polyploidization. Spurred by technological advances, a lot has been learned about these aspects both in model and increasingly also in nonmodel species. Despite this enormous progress, long-standing questions about polyploidy still cannot be unambiguously answered, due to frequently idiosyncratic outcomes and insufficient integration of different organizational levels (from genes to ecology), but likely this will change in the near future. See also the sister article focusing on animals by Choleva and Janko in this themed issue.
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Affiliation(s)
- H. Weiss-Schneeweiss
- Department of Systematic and Evolutionary Botany University of Vienna, Rennweg 14 AT–1030 Vienna (Austria)
| | - K. Emadzade
- Department of Systematic and Evolutionary Botany University of Vienna, Rennweg 14 AT–1030 Vienna (Austria)
| | - T.-S. Jang
- Department of Systematic and Evolutionary Botany University of Vienna, Rennweg 14 AT–1030 Vienna (Austria)
| | - G.M. Schneeweiss
- Department of Systematic and Evolutionary Botany University of Vienna, Rennweg 14 AT–1030 Vienna (Austria)
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Krejčíková J, Sudová R, Lučanová M, Trávníček P, Urfus T, Vít P, Weiss-Schneeweiss H, Kolano B, Oberlander K, Dreyer LL, Suda J. High ploidy diversity and distinct patterns of cytotype distribution in a widespread species of Oxalis in the Greater Cape Floristic Region. ANNALS OF BOTANY 2013; 111:641-9. [PMID: 23425783 PMCID: PMC3605962 DOI: 10.1093/aob/mct030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND AIMS Genome duplication is widely acknowledged as a major force in the evolution of angiosperms, although the incidence of polyploidy in different floras may differ dramatically. The Greater Cape Floristic Region of southern Africa is one of the world's biodiversity hotspots and is considered depauperate in polyploids. To test this assumption, ploidy variation was assessed in a widespread member of the largest geophytic genus in the Cape flora: Oxalis obtusa. METHODS DNA flow cytometry complemented by confirmatory chromosome counts was used to determine ploidy levels in 355 populations of O. obtusa (1014 individuals) across its entire distribution range. Ecological differentiation among cytotypes was tested by comparing sets of vegetation and climatic variables extracted for each locality. KEY RESULTS Three majority (2x, 4x, 6x) and three minority (3x, 5x, 8x) cytotypes were detected in situ, in addition to a heptaploid individual originating from a botanical garden. While single-cytotype populations predominate, 12 mixed-ploidy populations were also found. The overall pattern of ploidy level distribution is quite complex, but some ecological segregation was observed. Hexaploids are the most common cytotype and prevail in the Fynbos biome. In contrast, tetraploids dominate in the Succulent Karoo biome. Precipitation parameters were identified as the most important climatic variables associated with cytotype distribution. CONCLUSIONS Although it would be premature to make generalizations regarding the role of genome duplication in the genesis of hyperdiversity of the Cape flora, the substantial and unexpected ploidy diversity in Oxalis obtusa is unparalleled in comparison with any other cytologically known native Cape plant species. The results suggest that ploidy variation in the Greater Cape Floristic Region may be much greater than currently assumed, which, given the documented role of polyploidy in speciation, has direct implications for radiation hypotheses in this biodiversity hotspot.
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Affiliation(s)
- Jana Krejčíková
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Prague, CZ-128 01 Czech Republic
- Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice 1, CZ-252 43 Czech Republic
| | - Radka Sudová
- Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice 1, CZ-252 43 Czech Republic
| | - Magdalena Lučanová
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Prague, CZ-128 01 Czech Republic
- Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice 1, CZ-252 43 Czech Republic
| | - Pavel Trávníček
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Prague, CZ-128 01 Czech Republic
- Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice 1, CZ-252 43 Czech Republic
| | - Tomáš Urfus
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Prague, CZ-128 01 Czech Republic
- Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice 1, CZ-252 43 Czech Republic
| | - Petr Vít
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Prague, CZ-128 01 Czech Republic
- Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice 1, CZ-252 43 Czech Republic
| | - Hanna Weiss-Schneeweiss
- Department of Systematic and Evolutionary Botany, Faculty Centre Botany, University of Vienna, Rennweg 14, Vienna, A-1030 Austria
| | - Bożena Kolano
- Department of Plant Anatomy and Cytology, Silesian University, Jagiellonska 28, 40-032 Katowice, Poland
| | | | - Leanne L. Dreyer
- Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa
| | - Jan Suda
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Prague, CZ-128 01 Czech Republic
- Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice 1, CZ-252 43 Czech Republic
- For correspondence. E-mail:
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McIntyre PJ. Cytogeography and genome size variation in the Claytonia perfoliata (Portulacaceae) polyploid complex. ANNALS OF BOTANY 2012; 110:1195-203. [PMID: 22962302 PMCID: PMC3478050 DOI: 10.1093/aob/mcs187] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Accepted: 07/05/2012] [Indexed: 05/18/2023]
Abstract
BACKGROUND AND AIMS Genome duplication is a central process in plant evolution and contributes to patterns of variation in genome size within and among lineages. Studies that combine cytogeography with genome size measurements contribute to our basic knowledge of cytotype distributions and their associations with variation in genome size. METHODS Ploidy and genome size were assessed with direct chromosome counts and flow cytometry for 78 populations within the Claytonia perfoliata complex, comprised of three diploid taxa with numerous polyploids that range to the decaploid level. The relationship between genome size and temperature and precipitation was investigated within and across cytotypes to test for associations between environmental factors and nuclear DNA content. KEY RESULTS A euploid series (n = 6) of diploids to octoploids was documented through chromosome counts, and decaploids were suggested by flow cytometry. Increased variation in genome size among populations was found at higher ploidy levels, potentially associated with differential contributions of diploid parental genomes, variation in rates of genomic loss or gain, or undetected hybridization. Several accessions were detected with atypical genome sizes, including a diploid population of C. parviflora ssp. grandiflora with an 18 % smaller genome than typical, and hexaploids of C. perfoliata and C. parviflora with genomes 30 % larger than typical. There was a slight but significant association of larger genome sizes with colder winter temperature across the C. perfoliata complex as a whole, and a strong association between lower winter temperatures and large genome size for tetraploid C. parviflora. CONCLUSIONS The C. perfoliata complex is characterized by polyploids ranging from tetraploid to decaploid, with large magnitude variation in genome size at higher ploidy levels, associated in part with environmental variation in temperature.
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Affiliation(s)
- Patrick J McIntyre
- University of California Davis and Center for Population Biology, 2320 Storer Hall, One Shields Avenue, Davis, CA 95616, USA.
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Pellicer J, Clermont S, Houston L, Rich TCG, Fay MF. Cytotype diversity in the Sorbus complex (Rosaceae) in Britain: sorting out the puzzle. ANNALS OF BOTANY 2012; 110:1185-93. [PMID: 22922587 PMCID: PMC3478048 DOI: 10.1093/aob/mcs185] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 07/09/2012] [Indexed: 05/25/2023]
Abstract
BACKGROUND AND AIMS Large-scale ploidy surveys using flow cytometry have become an essential tool to study plant genome dynamics and to gain insight into the mechanisms and genetic barriers framing ploidy diversity. As an ideal complement to traditional techniques such as chromosome counting, the analysis of cytotype diversity in plant systems such as Sorbus provides primary investigation into the potential patterns and evolutionary implications of hybrid speciation. METHODS Ploidy was assessed by means of relative nuclear DNA content using propidium iodide flow cytometry in 474 Sorbus samples collected from 65 populations in southern Wales and South-West England. Statistical tests were applied to evaluate the utility of this technique to confidently discriminate ploidy in the genus. KEY RESULTS Flow cytometric profiles revealed the presence of four cytotypes (2x, 3x, 4x and 5x), confirming in many cases chromosome counts previously reported and demonstrating cytotype heterogeneity within specific Sorbus aggregates. Diploid cytotypes were restricted to the potential parental species and homoploid hybrids. Most of the samples processed were polyploid. The occurrence of the pentaploid cytotype had previously only been reported from a single specimen; it is now confirmed for two taxa occurring at different sites. CONCLUSIONS Flow cytometry results obtained have proved useful in shedding light on the taxonomy of several controversial taxa and in confirming the presence of cytoypes which occur at very low frequencies. Notably, the coexistence of several cytotypes in Sorbus populations has probably been facilitated by the overlapping distribution of many of the species studied, which might also explain the high incidence of potential hybrid apomictic polyploids. These results will provide a solid baseline for molecular research aiming to better understand the genetic pathways controlling the formation and establishment of polyploid Sorbus.
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Affiliation(s)
- Jaume Pellicer
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK.
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Praça-Fontes MM, Carvalho CR, Clarindo WR. C-value reassessment of plant standards: an image cytometry approach. PLANT CELL REPORTS 2011; 30:2303-12. [PMID: 21850594 DOI: 10.1007/s00299-011-1135-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 07/02/2011] [Accepted: 08/02/2011] [Indexed: 05/11/2023]
Abstract
Image cytometry (ICM) has been used to measure DNA 2C-values by evaluating the optical density of Feulgen-stained nuclei. This optical measurement is carried out using three basic tools: microscopy, digital video camera, and image analysis software. Because ICM has been applied to plants, some authors have remarked that studies should be performed before this technique can be accepted as an accurate method for determination of plant genome size. Based on this, the 2C-value of eight plants, which are widely used as standards in DNA quantifications, was reassessed in a cascade-like manner, from A. thaliana through R. sativus, S. lycopersicum, Glycine max, Z. mays, P. sativum, V. faba, to A. cepa. The mean 2C-values of all plants were statistically compared to the values reported by other authors using flow cytometry and/or ICM. These analyses demonstrated that ICM is an accurate and reliable method for 2C-value measurement, representing an attractive alternative to flow cytometry. Statistical comparison of the results also indicated Glycine max 'Polanka' as the most adequate primary standard. However, distinct authors have been advised that 2C DNA content of the reference standard should be close to that of the sample. As three further approaches also revisited the 2C-value of these eight plants, we have thus proposed a mean 2C-value for each eight species.
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Affiliation(s)
- Milene Miranda Praça-Fontes
- Laboratório de Microscopia, Departamento de Produção Vegetal, Centro de Ciências Agrárias, Universidade Federal do Espírito Santo, CEP 29500-000, Alegre, ES, Brazil
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Delaney JT, Baack EJ. Intraspecific Chromosome Number Variation and Prairie Restoration-A Case Study in Northeast Iowa, U.S.A. Restor Ecol 2011. [DOI: 10.1111/j.1526-100x.2011.00825.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Praça-Fontes MM, Carvalho CR, Clarindo WR, Cruz CD. Revisiting the DNA C-values of the genome size-standards used in plant flow cytometry to choose the "best primary standards". PLANT CELL REPORTS 2011; 30:1183-91. [PMID: 21318354 DOI: 10.1007/s00299-011-1026-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 01/17/2011] [Accepted: 01/24/2011] [Indexed: 05/21/2023]
Abstract
Flow cytometry (FCM) techniques have enabled characterization of the genome size for various plant species. In order to measure the nuclear genome size of a species, reference standards with well-established DNA content are necessary. However, different 2C-values have been described for the same species used as reference standard. This fact has brought about inaccurate genome measurements, making relevant the establishment of optimal DNA reference standards for plant cytometric analyses. Our work revisited the genome size of Arabidopsis thaliana and other seven plant standards, which were denominated "Doležel's standard set" and have been widely used in plant DNA measurements. These eight plant standards were reassessed for a comparative measurement of their DNA content values, using each plant species as primary standard in a cascade-like manner, from A. thaliana to Allium cepa. The genome size values obtained here were compared to those reported in the literature by statistical analyses. As a result, Raphanus sativus and Drosophila melanogaster were considered the most inadequate primary standards, whereas A. thaliana, Solanum lycopersicum and Pisum sativum were found to be the most suitable.
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Affiliation(s)
- Milene Miranda Praça-Fontes
- Laboratório de Microscopia, Departamento de Produção Vegetal, Centro de Ciências Agrárias, Universidade Federal do Espírito Santo, Alegre, ES, Brazil
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Trávníček P, Kubátová B, Čurn V, Rauchová J, Krajníková E, Jersáková J, Suda J. Remarkable coexistence of multiple cytotypes of the Gymnadenia conopsea aggregate (the fragrant orchid): evidence from flow cytometry. ANNALS OF BOTANY 2011; 107:77-87. [PMID: 21059612 PMCID: PMC3002475 DOI: 10.1093/aob/mcq217] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2010] [Revised: 07/27/2010] [Accepted: 10/04/2010] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS One of the prerequisites for polyploid research in natural systems is knowledge of the geographical distribution of cytotypes. Here inter- and intrapopulational ploidy diversity was examined in the Gymnadenia conopsea aggregate in central Europe and potential explanations and evolutionary consequences of the observed spatial patterns investigated. METHODS DAPI flow cytometry supplemented by confirmatory chromosome counts was used to determine ploidy in 3581 samples of the G. conopsea aggregate from 43 populations. The fine-scale spatial pattern of cytotype distribution (intra- and interploidy associations) was analysed with univariate and bivariate K-functions. KEY RESULTS Gymnadenia tissues undergo a progressively partial endoreplication, which accounts for about 60 % and 75 % of the total genome in G. conopsea and G. densiflora, respectively. Flow cytometric profiles are therefore species-specific and can be used as a marker for rapid and reliable species recognition. Two majority (4x, 8x) and three minority (6x, 10x, 12x) cytotypes were found, often in mixed-ploidy populations (harbouring up to all five different ploidy levels). The scarcity of the minority cytotypes (about 2·7 %) suggests the existence of strong pre- or postzygotic mating barriers. Spatial structure was observed in plots of populations with the highest cytotype variation, including clumping of individuals of the same ploidy and negative association between tetra- and octoploids. CONCLUSIONS The remarkable ploidy coexistence in the G. conopsea aggregate has reshaped our perception of intrapopulational ploidy diversity under natural conditions. This system offers unique opportunities for studying processes governing the formation and establishment of polyploids and assessing the evolutionary significance of the various pre- and postzygotic mating barriers that maintain this ploidy mixture.
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Affiliation(s)
- Pavel Trávníček
- Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43 Průhonice, Czech Republic
- Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01 Prague, Czech Republic
| | - Barbora Kubátová
- Biotechnological Centre, Faculty of Agriculture, University of South Bohemia, CZ-370 05 České Budějovice, Czech Republic
| | - Vladislav Čurn
- Biotechnological Centre, Faculty of Agriculture, University of South Bohemia, CZ-370 05 České Budějovice, Czech Republic
| | - Jana Rauchová
- Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43 Průhonice, Czech Republic
- Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01 Prague, Czech Republic
| | - Eva Krajníková
- Biotechnological Centre, Faculty of Agriculture, University of South Bohemia, CZ-370 05 České Budějovice, Czech Republic
| | - Jana Jersáková
- Faculty of Science, University of South Bohemia and Institute of System Biology and Ecology, CZ-370 05 České Budějovice, Czech Republic
| | - Jan Suda
- Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43 Průhonice, Czech Republic
- Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01 Prague, Czech Republic
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Sonnleitner M, Flatscher R, Escobar García P, Rauchová J, Suda J, Schneeweiss GM, Hülber K, Schönswetter P. Distribution and habitat segregation on different spatial scales among diploid, tetraploid and hexaploid cytotypes of Senecio carniolicus (Asteraceae) in the Eastern Alps. ANNALS OF BOTANY 2010; 106:967-77. [PMID: 20880930 PMCID: PMC2990664 DOI: 10.1093/aob/mcq192] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 07/27/2010] [Accepted: 08/24/2010] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND AIMS The spatial distribution of cytotypes can provide valuable insights into evolutionary patterns of polyploid complexes. In a previous study the macro-scale distribution of the three main cytotypes in Senecio carniolicus (Asteraceae) within the Eastern Alps was characterized. Employing a roughly 12-fold extended sampling, the present study focuses on unravelling patterns of cytotype distribution on the meso- and microscale and on correlating those with ecological properties of the growing sites. METHODS DAPI flow cytometry of dried samples was used to determine DNA ploidy level in 5033 individuals from 100 populations spread over the entire Eastern Alpine distribution area of S. carniolicus. Descriptors of microhabitats as well as spatial data were recorded in the field, and analysed with a mixed-effects ANOVA. KEY RESULTS Extensive variation in DNA ploidy levels (2x, 3x, 4x, 5x, 6x, 7x, 8x, 9x) was detected. Of the main cytotypes, diploids and hexaploids were widespread and had strongly overlapping distributions resulting in the frequent occurrence of cytotype mixtures (half of the investigated populations), whereas tetraploids were disjunctly distributed and occurred in the south-west and the east of the species' distribution area. In spite of the frequent co-occurrence of cytotypes, only 1 % of the samples belonged to secondary cytotypes (3x, 5x, 7x, 8x, 9x). Diploids, tetraploids and hexaploids were altitudinally segregated, but with broad overlap. Similarly, highly significant differences in vegetation and rock cover as well as microhabitat exposure were found between the main cytotypes. CONCLUSIONS Senecio carniolicus shows a remarkable diversity of cytotypes. The distribution of the three main cytotypes (2x, 4x, 6x) has been shaped by Pleistocene glaciations to different extents. Whereas tetraploids are nearly entirely restricted to refugia, hexaploids colonized areas that were extensively glaciated. Diploid and hexaploid individuals often co-occur in mixed populations, where they are spatially and ecologically segregated at both the meso-scale (altitudinal differentiation, exposure of the growing site) and the micro-scale (cover of vegetation and bare rock). With regard to the ecological parameters investigated, the tetraploid cytotype occupies an intermediate position. The rareness of secondary cytotypes suggests the presence of strong pre- or post-zygotic mating barriers.
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Affiliation(s)
- Michaela Sonnleitner
- Department of Biogeography and Botanical Garden, University of Vienna, Rennweg 14, Vienna 1030, Austria
| | - Ruth Flatscher
- Department of Biogeography and Botanical Garden, University of Vienna, Rennweg 14, Vienna 1030, Austria
| | - Pedro Escobar García
- Department of Biogeography and Botanical Garden, University of Vienna, Rennweg 14, Vienna 1030, Austria
| | - Jana Rauchová
- Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice 1, CZ-252 43, Czech Republic
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Prague, CZ-128 01, Czech Republic
| | - Jan Suda
- Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice 1, CZ-252 43, Czech Republic
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Prague, CZ-128 01, Czech Republic
| | - Gerald M. Schneeweiss
- Department of Biogeography and Botanical Garden, University of Vienna, Rennweg 14, Vienna 1030, Austria
- Systematic Botany and Mycology, Ludwig-Maximilians-University Munich, Menzingerstrasse 61, D-80638 Munich, Germany
| | - Karl Hülber
- Vienna Institute for Nature Conservation & Analyses, Giessergasse 6/7, Vienna 1090, Austria
- Department of Conservation Biology, Vegetation Ecology and Landscape Ecology, University of Vienna, Rennweg 14, Vienna 1030, Austria
| | - Peter Schönswetter
- Department of Biogeography and Botanical Garden, University of Vienna, Rennweg 14, Vienna 1030, Austria
- Department of Systematics, Palynology and Geobotany, Institute of Botany, University of Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria
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