Folia Geobotanica

, Volume 50, Issue 2, pp 123–136 | Cite as

Population genetic structure and clonal diversity of Allium oleraceum (Amaryllidaceae), a polyploid geophyte with common asexual but variable sexual reproduction

  • Martin Duchoslav
  • Hana Staňková


Clonal plants are, on average, considered to be as genetically diverse as nonclonal plants. However, the behaviour of clonal plants ranges between multiclonality and uniclonality, depending on environmental conditions and life history traits. Allozyme electrophoresis of band phenotypes was used to examine the genetic structure of 13 cytotype-uniform and 17 cytotype-mixed populations of polyploid Allium oleraceum (2n = 4x, 5x, 6x), a clonal bulbous geophyte that has been considered seed-sterile and completely reliant on vegetative reproduction through aerial bulbils and daughter bulbs. The genetic structure was dominated by low within-population variation whereas genetic differentiation was high among populations. Eighty-five distinct multilocus genotypes were found among 756 sampled individuals, but populations generally exhibited a low level of clonal diversity. Tetra- and pentaploids showed twofold higher total and within-population diversity, but also had more genetically differentiated populations in comparison with hexaploids. Tetraploids formed two separate groups in the cluster analysis, and this finding most likely suggests their different origin. Pentaploids were grouped in a separate cluster and frequently intermixed with tetra- and hexaploids sampled at cytotype-mixed sites. Such a pattern suggests gene flow between cytotypes. Most hexaploids were genetically similar and clustered separately from the other cytotypes, suggesting their similar origin and absence of gene flow to and from other cytotypes. Identical band phenotypes found in coexisting cytotypes within certain mixed-ploidy populations might indicate in situ neopolyploidization. Collectively, the pattern of genetic structure and diversity observed in A. oleraceum is typical of clonal plants with the dominance of vegetative offspring and scarce recruitment of sexual offspring. The low and spatially unstructured genetic variation observed in hexaploids, in contrast with higher and spatially structured genetic variation in tetra- and pentaploids, seems to be related to different levels of sexual fertility, ecological amplitude and colonization abilities of the cytotypes. It provides evidence for the existence of both primary and secondary contact zones of cytotypes in A. oleraceum.


allozymes clonality Czech Republic genotypes polyploidy residual sexuality spatial structure 



We thank Jiří Ohryzek and Lenka Šafářová for their help with the fieldwork and Lenka Šafářová for measuring plants by flowcytometer. Jan Štěpánek, Lenka Plačková (Institute of Botany of the Czech Academy of Sciences, Průhonice), Marta Khoylou and Miloslav Kitner (Palacký University) are greatly acknowledged for helping with the isozyme electrophoresis. Comments and corrections by František Krahulec, Luboš Majeský and three anonymous referees helped to improve previous versions of this article. This work was supported by the Grant Agency of the Czech Republic (grant numbers 206/01/P097, 206/04/P115 and 206/09/1126) and its completion by an internal grant from Palacký University (PrF-2015-001).

Supplementary material

12224_2015_9213_MOESM1_ESM.pdf (143 kb)
Electronic supplementary material 1 Schematic banding patterns (zymograms) obtained for five loci in Allium oleraceum. All the inferred phenotypes and the number and percentage of individuals belonging to the ploidy level showing each phenotype are given below each phenotype. SHDH is monomeric enzyme and each band potentially represents expression of a different allele. In a dimeric enzyme (6-PGDH, IDH, EST), heterozygotes yield multibanded pattern with homodimeric and heterodimeric bands. However, observed banding pattern lacks six-banded phenotype that was expected when three alleles of dimeric enzyme are expressed; only five bands were visible. Concerning NADHDH (monomer, dimer, tetramer?), we observed really complex banding pattern. Because additional genetic and non-genetic phenomena (e.g. overlap of different loci, existence of secondary bands and null alleles, comigration of products specified by different loci) probably complicated zymogram interpretation (Wendel and Weeden 1989), only presence/absence of different bands was considered in all analyses. Rf = retention factor. (PDF 142 kb)
12224_2015_9213_Fig3_ESM.gif (35 kb)
Electronic supplementary material 2

Principal Coordinate Analysis (PCoA) of A. oleraceum populations (the second data set). Tetraploid populations are in green, pentaploid in red and hexaploid populations in blue, respectively. Two-colour symbols represent overlapped points of respective populations (mixed-cytotype populations). Percentage of variation explained by each coordinate is noted in the diagram. For population abbreviations, see Table 1. (GIF 34 kb)

12224_2015_9213_MOESM2_ESM.tif (30.8 mb)
High resolution image (TIFF 31522 kb)


  1. Arnaud-Haond S, Alberto F, Teixeira S, Procaccini G, Serrão EA, Duarte CM (2005) Assessing genetic diversity in clonal organisms: low diversity or low resolution? Combining power and cost efficiency in selecting markers. J Hered 96:1–7CrossRefGoogle Scholar
  2. Åström H, Hæggström CA (2004) Generative reproduction in Allium oleraceum (Alliaceae). Ann Bot Fennici 41:1–14Google Scholar
  3. Baack EJ (2004) Cytotype segregation on regional and microgeographic scales in snow buttercups (Ranunculus adoneus: Ranunculaceae). Amer J Bot 91:1783–1788CrossRefGoogle Scholar
  4. Balao F, Casimiro-Soriguer R, Talavera M, Herrera J, Talavera S (2009) Distribution and diversity of cytotypes in Dianthus broteri as evidenced by genome size variations. Ann Bot (Oxford) 104:965–973CrossRefGoogle Scholar
  5. Bauert MR, Kalin M, Baltisberger M, Edwards PJ (1998) No genetic variation detected within isolated relict populations of Saxifraga cernua in the Alps using RAPD markers. Molec Ecol 7:1519–1527CrossRefGoogle Scholar
  6. Brown AHD, Weir BS (1983) Measuring genetic variability in plant populations. In Tanksley AD, Orton TJ (eds) Isozymes in plant genetics and breeding, part A, Elsevier Science, Amsterdam, pp 219–239Google Scholar
  7. Bussell JD (1999) The distribution of random amplified polymorphic DNA (RAPD) diversity amongst populations of Isotoma petraea (Lobeliaceae). Molec Ecol 8:775–789CrossRefGoogle Scholar
  8. Castro S, Loureiro J, Procházka T, Münzbergová Z (2012) Cytotype distribution at a diploid-hexaploid contact zone in Aster amellus (Asteraceae). Ann Bot (Oxford) 110:1047–1055CrossRefGoogle Scholar
  9. Ceplitis A (2001) The importance of sexual and asexual reproduction in the recent evolution of Allium vineale. Evolution 55:1581–1591PubMedCrossRefGoogle Scholar
  10. Diggle PK, Lower S, Ranker TA (1998) Clonal diversity in alpine populations of Polygonum viviparum (Polygonaceae). Int J Plant Sci 159:606–615CrossRefGoogle Scholar
  11. Dijk P van, Hartog MV, Delden W van (1992) Single cytotype areas in autopolyploid Plantago media L. Biol J Linn Soc 46:315–331Google Scholar
  12. Dolan RW (1994) Patterns of allozyme variation in relation to population size, isolation and phytogeographic history in royal catchfly (Silene regia: Caryophyllaceae). Amer J Bot 81:965–972CrossRefGoogle Scholar
  13. Duchoslav M (2001a) Allium oleraceum and A. vineale in the Czech Republic: distribution and habitat differentiation. Preslia 73:173–184Google Scholar
  14. Duchoslav M (2001b) Small-scale spatial pattern of two common European geophytes Allium oleraceum and A. vineale in contrasting habitats. Biologia 56:57–62Google Scholar
  15. Duchoslav M (2009) Effects of contrasting habitats on the phenology, seasonal growth, and dry-mass allocation pattern of two bulbous geophytes (Alliaceae) with partly different geographic ranges. Pol J Ecol 57:15–32Google Scholar
  16. Duchoslav M, Šafářová L, Krahulec F (2010) Complex distribution patterns, ecology and coexistence of ploidy levels of Allium oleraceum (Alliaceae) in the Czech Republic. Ann Bot (Oxford) 105:719–735CrossRefGoogle Scholar
  17. Duchoslav M, Šafářová L, Jandová M (2013) Role of adaptive and non-adaptive mechanisms forming complex patterns of genome size variation in six cytotypes of polyploid Allium oleraceum (Amaryllidaceae) on a continental scale. Ann Bot (Oxford) 111:419–431CrossRefGoogle Scholar
  18. Eckert CG (1999) Clonal plant research: proliferation, integration, but not much evolution. Amer J Bot 86:1649–1654CrossRefGoogle Scholar
  19. Eckert CG. (2000) The loss of sex in clonal plants. Evol Ecol 15:501–520CrossRefGoogle Scholar
  20. Eckert CG, Barrett SCH (1993) Clonal reproduction and patterns of genotypic diversity in Decodon verticillatus (Lythraceae). Amer J Bot 80:1175–1182CrossRefGoogle Scholar
  21. Eckstein RL, O’Neill RA, Danihelka J, Otte A, Kohler W (2006) Genetic structure among and within peripheral and central populations of three endangered floodplain violets. Molec Ecol 15:2367–2379CrossRefGoogle Scholar
  22. Eliášová A, Trávníček P, Mandák B, Münzbergová Z (2014) Autotetraploids of Vicia cracca show a higher allelic richness in natural populations and a higher seed set after artificial selfing than diploids. Ann Bot (Oxford) 113:159–170CrossRefGoogle Scholar
  23. Ellstrand NC, Roose ML (1987) Patterns of genotypic diversity in clonal plant species. Amer J Bot 74:123–131CrossRefGoogle Scholar
  24. Fialová M, Duchoslav M (2014) Response to competition of bulbous geophyte Allium oleraceum differing in ploidy level. Plant Biol 16:186–196CrossRefGoogle Scholar
  25. Fialová M, Ohryzek J, Jandová M, Duchoslav M (2014) Biology of the polyploid geophyte Allium oleraceum (Amaryllidaceae): variation in size, sexual and asexual reproduction and germination within and between tetra-, penta- and hexaploid cytotypes. Flora 209:312–324CrossRefGoogle Scholar
  26. Fialová R (1996) Polyploid complexes within genus Allium [PhD. thesis, depon. in Faculty of Science, Palacký University, Olomouc]Google Scholar
  27. Hamrick JL, Godt MJW (1997) Effects of life history traits on genetic diversity in plant species. In Silvertown J, Franco M, Harper JL (eds) Plant life histories. Cambridge University Press, Cambridge, pp 102–118Google Scholar
  28. Hammer Ø, Harper DAT, Ryan PD (2001) PAST: Paleontological Statistics Software Package for Education and Data Analysis. Palaeontologia Electronica 4
  29. Hancock Jr. JF, Wilson RE (1976) Biotype selection in Erigeron annuus during old field succession. Bull Torrey Bot Club 103:122–125CrossRefGoogle Scholar
  30. Hardy OJ, Vanderhoeven S, de Loose M, Meerts P. (2000) Ecological, morphological and allozymic differentiation between diploid and tetraploid knapweeds (Centaurea jacea) from a contact zone in the Belgian Ardennes. New Phytol 146:281–290CrossRefGoogle Scholar
  31. Hendrych R (1987) Karpatische Migrationen und Florenbeziehungen in den tschechischen Ländern der Tschechoslowakei. Acta Univ Carol Biol 1985:105–250Google Scholar
  32. Hintze J (2013) NCSS 9. NCSS, LLC. Kaysville
  33. Honnay O, Bossuyt B (2005) Prolonged clonal growth: escape route or route to extinction? Oikos 108:427–432CrossRefGoogle Scholar
  34. Honnay O, Jacquemyn H (2008) A meta-analysis of the relation between mating system, growth form and genotypic diversity in clonal plant species. Evol Ecol 22:299–312CrossRefGoogle Scholar
  35. Hörandl E (2006) The complex causality of geographical parthenogenesis. New Phytol 171:525–538PubMedGoogle Scholar
  36. Hörandl E, Jakubowsky G, Dobeš C (2001) Isozyme and morphological diversity within apomictic and sexual taxa of the Ranunculus auricomus complex. Pl Syst Evol 226:165–185CrossRefGoogle Scholar
  37. Hutchison DW, Templeton AR (1999) Correlation of pairwise genetic and geographic distance measures: inferring the relative influences of gene flow and drift on the distribution of genetic variability. Evolution 53:1898–1914CrossRefGoogle Scholar
  38. Ježilová E, Nožková-Hlaváčková V, Duchoslav M (2014) Photosynthetic characteristics of three ploidy levels of Allium oleraceum L. (Amaryllidaceae) differing in ecological amplitude. Plant Spec Biol (DOI: 10.1111/1442-1984.12053)Google Scholar
  39. Jones B, Gliddon C (1999) Reproductive biology and genetic structure in Lloydia serotina. Plant Ecol 141:151–161CrossRefGoogle Scholar
  40. Kato T (1987) Hybridization between Dianthus superbus var. longicalycinus and D. shinanensis evidenced by resolvable esterase isozymes from herbarium specimens. Ann Tsukuba Bot Gard 6:9–18Google Scholar
  41. Kephart SR (1990) Starch gel electrophoresis of plant isozymes: a comparative analysis of techniques. Amer J Bot 77:693–712CrossRefGoogle Scholar
  42. Kim S, Rayburn AL, Boe A, Lee DK (2012) Neopolyploidy in Spartina pectinata Link: 1. Morphological analysis of tetraploid and hexaploid plants in a mixed natural population. Pl Syst Evol 298:1073–1083CrossRefGoogle Scholar
  43. Kirschner J, Bartish I, Hroudová Z, Kirschnerová L, Zákravský P (2004) Contrasting patterns of spatial genetic structure of diploid and triploid populations of the clonal aquatic species, Butomus umbellatus (Butomaceae), in central Europe. Folia Geobot 39:13–26CrossRefGoogle Scholar
  44. Klimeš L, Klimešová J, Hendriks R, Groenendael J van (1997) Clonal plant architecture: comparative analysis of form and function. In de Kroon H, Groenendael J van (eds) The ecology and evolution of clonal plants. Backhuys Publishers, Leiden, pp 1–29Google Scholar
  45. Klimešová J, Klimeš L (2008) Clonal growth diversity and bud banks of plants in the Czech flora: an evaluation using the CLO-PLA3 database. Preslia 80:255–275Google Scholar
  46. Kolář F, Štech M, Trávníček P, Rauchová J, Urfus T, Vít P, Kubešová M, Suda J (2009) Towards resolving the Knautia arvensis agg. (Dipsacaceae) puzzle: primary and secondary contact zones and ploidy segregation at landscape and microgeographic scales. Ann Bot (Oxford) 103:963–974CrossRefGoogle Scholar
  47. Konvička O (1972) Cytotaxonomische Studien von vier sterilen Arten der Gattung Allium. Biol Plantarum 14:62–70CrossRefGoogle Scholar
  48. Lacy RC (1987) Loss of genetic diversity from managed populations: interacting effects of drift, mutation, immigration, selection, and population subdivision. Conserv Biol 1:143–158CrossRefGoogle Scholar
  49. Levan A (1933) Cytological studies in Allium, III. Allium carinatum and Allium oleraceum. Hereditas 18:101–114CrossRefGoogle Scholar
  50. Levan A (1938) Cytological studies in the Allium paniculatum group. Hereditas 23:317–370CrossRefGoogle Scholar
  51. Lo EYY, Stefanovic S, Dickinson TA (2009) Population genetic structure of diploid sexual and polyploid apomictic hawthorns (Crataegus; Rosaceae) in the Pacific Northwest. Molec Ecol 18:1145–1160CrossRefGoogle Scholar
  52. López-Pujol J, Orellana MR, Bosch M, Simon J, Blanche C (2007) Low genetic diversity and allozymic evidence for autopolyploidy in the tetraploid Pyrenean endemic larkspur Delphinium montanum (Ranunculaceae). Bot J Linn Soc 155:211–222CrossRefGoogle Scholar
  53. Lozano R, Ruiz Rejón C, Ruiz Rejón M (1986) Interchange polymorphism in natural populations of Allium paniculatum L. (Liliaceae): nature, frequency, effects, and mechanism of maintenance. Can J Genet Cytol 28:348–357CrossRefGoogle Scholar
  54. Lumaret R (1988) Cytology, genetics and evolution in the genus Dactylis. Crit Rev Plant Sci 7:55–91CrossRefGoogle Scholar
  55. Macdonald SE, Lieffers VJ (1991) Population variation, outcrossing and colonization of disturbed areas by Calamagrostis canadensis: evidence from allozyme analysis. Amer J Bot 78:1123–1129CrossRefGoogle Scholar
  56. Matzk F, Meister A, Schubert I (2000) An efficient screen for reproductive pathways using mature seeds of monocots and dicots. Plant J 21:97–108PubMedCrossRefGoogle Scholar
  57. Mráz P, Šingliarová B, Urfus T, Krahulec F (2008) Cytogeography of Pilosella officinarum (Compositae): altitudinal and longitudinal differences in ploidy level distribution in the Czech Republic and the general pattern in Europe. Ann Bot (Oxford) 101:59–71CrossRefGoogle Scholar
  58. Nybom H, Bartish IV (2000) Effects of life history traits and sampling strategies on genetic diversity estimates obtained with RAPD markers in plants. Persp Plant Ecol Evol Syst 3:93–114CrossRefGoogle Scholar
  59. Parisod C, Holderegger R, Brochmann C. (2010) Evolutionary consequences of autopolyploidy. New Phytol 186:5–17PubMedCrossRefGoogle Scholar
  60. Paschke M, Abs C, Schmid B (2002) Relationship between population size, allozyme variation, and plant performance in the narrow endemic Cochlearia bavarica. Conserv Genet 3:131–144CrossRefGoogle Scholar
  61. Peckert T, Chrtek J Jr, Plačková I (2005) Genetic variation in agamospermous populations of Hieracium echioides in southern Slovakia and northern Hungary (Danube Basin). Preslia 77:307–315Google Scholar
  62. Petit C, Bretagnolle F, Felber F (1999) Evolutionary consequences of diploid-polyploid hybrid zones in wild species. Trends Ecol Evol 14:306–311PubMedCrossRefGoogle Scholar
  63. Pfeiffer T, Klahr A, Peterson A, Levichev IG, Schnittler M (2012) No sex at all? Extremely low genetic diversity in Gagea spathacea (Liliaceae) across Europe. Flora 207:372–378CrossRefGoogle Scholar
  64. Piquot Y, Petit D, Valero M, Cuguen J, de Laguerie P, Vernet P (1998) Variation in sexual and asexual reproduction among young and old populations of the perennial macrophyte Sparganium erectum. Oikos 82:139–148CrossRefGoogle Scholar
  65. Pleasant JM, Wendel JF (1989) Genetic diversity in clonal narrow endemic Erythronium propullans, and its widespread progenitor, Erythronium albidum. Amer J Bot 76:1136–1151CrossRefGoogle Scholar
  66. Ramsey J (2011) Polyploidy and ecological adaptation in wild yarrow. Proc Natl Acad Sci USA 108:7096–7101PubMedCentralPubMedCrossRefGoogle Scholar
  67. Ramsey J, Schemske D (2002) Neopolyploidy in flowering plants. Ann Rev Ecol Syst 33:589–639CrossRefGoogle Scholar
  68. Rangel TF, Diniz-Filho JAF, Bini LM (2010) SAM: a comprehensive application for spatial analysis in macroecology. Ecography 33:1–5CrossRefGoogle Scholar
  69. Richens RH (1947) Biological flora of the British Isles. Allium vineale L. J Ecol 34:209–227CrossRefGoogle Scholar
  70. Ronsheim ML (1994) Dispersal distances and predation rates of sexual and asexual propagules of Allium vineale L. Amer Midl Naturalist 131:55–64CrossRefGoogle Scholar
  71. Ronsheim ML (1997) Distance-dependent performance of asexual progeny in Allium vineale (Liliaceae). Amer J Bot 84:1279–1284CrossRefGoogle Scholar
  72. Šafářová L, Duchoslav M (2010) Cytotype distribution in mixed populations of polyploid Allium oleraceum measured at a microgeographic scale. Preslia 82:107–126Google Scholar
  73. Šafářová L, Duchoslav M, Jandová M, Krahulec F (2011) Allium oleraceum in Slovakia: cytotype distribution and ecology. Preslia 83:513–527Google Scholar
  74. Silvertown J (2008) The evolutionary maintenance of sexual reproduction: evidence from the ecological distribution of asexual reproduction in clonal plants. Int J Plant Sci 169:157–168CrossRefGoogle Scholar
  75. Šingliarová B, Chrtek J, Plačková I, Mráz P (2011) Allozyme variation in diploid, polyploid and mixed-ploidy populations of the Pilosella alpicola group (Asteraceae): relation to morphology, origin of polyploids and breeding system. Folia Geobot 46:387–410CrossRefGoogle Scholar
  76. Solbrig OT, Simpson BB (1974) Components of regulation of a population of dandelions in Michigan. J Ecol 62:473–486CrossRefGoogle Scholar
  77. Soltis DE, Soltis PS (1989) Genetic consequences of autopolyploidy in Tolmiea (Saxifragaceae). Evolution 43:586–594CrossRefGoogle Scholar
  78. Soltis PS, Soltis DE (2000) The role of genetic and genomic attributes in the success of polyploids. Proc Natl Acad Sci USA 97:7051–7057PubMedCentralPubMedCrossRefGoogle Scholar
  79. Soltis DE, Visger CJ, Soltis PS (2014) The polyploidy revolution then…and now: Stebbins revisited. Amer J Bot 101:1057–1078CrossRefGoogle Scholar
  80. Starfinger U, Stöcklin J (1996) Seed, pollen, and clonal dispersal and their role in structuring plant populations. Progr Bot 57:336–355Google Scholar
  81. Stehlik I, Holderegger R (2000) Spatial genetic structure and clonal diversity of Anemone nemorosa in late successional deciduous woodlands of Central Europe. J Ecol 88:424–435CrossRefGoogle Scholar
  82. Stoddart JA, Taylor JF (1988) Genotypic diversity: estimation and prediction in samples. Genetics 118:705–711PubMedCentralPubMedGoogle Scholar
  83. Štorchová H, Chrtek J Jr, Bartish IV, Tetera M, Kirschner J, Štěpánek J (2002) Genetic variation in agamospermous taxa of Hieracium sect. Alpina (Compositae) in the Tatry Mts (Slovakia). Pl Syst Evol 235:1–17CrossRefGoogle Scholar
  84. Stuessy TF, Weiss-Schneeweiss H, Keil DJ (2004) Diploid and polyploid cytotype distribution in Melampodium cinereum and M. leucanthum (Asteraceae, Heliantheae). Amer J Bot 91:889–898CrossRefGoogle Scholar
  85. Trávníček P, Eliášová A, Suda J (2010) The distribution of cytotypes of Vicia cracca in Central Europe: the changes that have occurred over the last four decades. Preslia 82:149–163Google Scholar
  86. Trávníček P, Dočkalová Z, Rosenbaumová R, Kubátová B, Szelag Z, Chrtek J (2011) Bridging global and microregional scales: ploidy distribution in Pilosella echioides (Asteraceae) in central Europe. Ann Bot (Oxford) 107:443–54CrossRefGoogle Scholar
  87. Treu R, Holmes DS, Smith BM, Astley D, Johnson MAT, Tureman LJ (2001) Allium ampeloprasum var. babingtonii (Alliaceae): an isoclonal plant found across a range of habitats in S.W. England. Plant Ecol 155:229–235CrossRefGoogle Scholar
  88. Vallejos CE (1983) Enzyme activity staining. In Tanksley DS, Orten T (eds) Isozyme in plant genetics and breeding. Elsevier, Amsterodam, pp 469–516Google Scholar
  89. Watkinson AR, Powell JC (1993) Seedling recruitment and the maintenance of clonal diversity in plant populations: a computer simulation of Ranunculus repens. J Ecol 81:707–717CrossRefGoogle Scholar
  90. Wendel JF, Weeden NF (1989) Visualisation and interpretation of plant isozymes. In Soltis DE, Soltis PS (eds) Isozymes in plant biology. Dioscoroides Press, Portland, pp 5–45CrossRefGoogle Scholar
  91. Weiss H, Dobeš C, Schneeweiss GM, Greimler J. (2002) Occurrence of tetraploid and hexaploid cytotypes between and within populations in Dianthus sect. Plumaria (Caryophyllaceae). New Phytol 156:85–94CrossRefGoogle Scholar
  92. Widén B, Cronberg N, Widén M (1994) Genotypic diversity molecular markers and spatial distribution of genets in clonal plants a literature survey. Folia Geobot Phytotax 29:245–263CrossRefGoogle Scholar

Copyright information

© Institute of Botany, Academy of Sciences of the Czech Republic 2015

Authors and Affiliations

  1. 1.Plant Biosystematics and Ecology RG, Department of Botany, Faculty of SciencePalacký UniversityOlomoucCzech Republic

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