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Basit A, Lim KB. Systematic approach of polyploidy as an evolutionary genetic and genomic phenomenon in horticultural crops. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 348:112236. [PMID: 39186951 DOI: 10.1016/j.plantsci.2024.112236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 08/15/2024] [Accepted: 08/18/2024] [Indexed: 08/28/2024]
Abstract
Polyploidy is thought to be an evolutionary and systematic mechanism for gene flow and phenotypic advancement in flowering plants. It is a natural phenomenon that promotes diversity by creating new permutations enhancing the prime potentials as compared to progenitors. Two different pathways have been recognized in studying polyploidy in nature; mitotic or somatic chromosome doubling and cytogenetics variation. Secondly, the vital influence of being polyploid is its heritable property (unreduced reproductive cells) formed during first and second-division restitution (FDR & SDR). Different approaches either chemical (Colchicine, Oryzalin, Caffeine, Trifuralin, or phosphoric amides) or gaseous i.e. Nitrous oxide have been deliberated as strong polyploidy causing agents. A wide range of cytogenetic practices like chromosomes study, ploidy, genome analysis, and plant morphology and anatomy have been studied in different plant species. Flow cytometry for ploidy and chromosome analysis through fluorescence and genomic in situ hybridization (FISH & GISH) are the basic methods to evaluate heredity substances sampled from leaves and roots. Many horticultural crops have been developed successfully and released commercially for consumption. Moreover, some deep detailed studies are needed to check the strong relationship between unique morphological features and genetic makeup concerning genes and hormonal expression in a strong approach.
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Affiliation(s)
- Abdul Basit
- Department of Horticultural Science, Kyungpook National University, Daegu 41566, South Korea.
| | - Ki-Byung Lim
- Department of Horticultural Science, Kyungpook National University, Daegu 41566, South Korea; Institute of Agricultural Science and Technology, Kyungpook National University, Daegu, South Korea.
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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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Kramer AT, Wood TE, Frischie S, Havens K. Considering ploidy when producing and using mixed-source native plant materials for restoration. Restor Ecol 2017. [DOI: 10.1111/rec.12636] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Andrea T. Kramer
- Plant Science and Conservation; Chicago Botanic Garden, 1000 Lake Cook Road; Glencoe IL 60022 U.S.A
- Program in Plant Biology and Conservation; Northwestern University, 633 Clark Street; Evanston IL 60208 U.S.A
| | | | - Stephanie Frischie
- Plant Science and Conservation; Chicago Botanic Garden, 1000 Lake Cook Road; Glencoe IL 60022 U.S.A
- Program in Plant Biology and Conservation; Northwestern University, 633 Clark Street; Evanston IL 60208 U.S.A
- 1 Semillas Silvestres, S.L., Calle Aulaga 24, 14012 Córdoba Spain
- Department of Earth and Environmental Sciences; University of Pavia; Corso Strada Nuova 65, 27100 Pavia Italy
| | - Kayri Havens
- Plant Science and Conservation; Chicago Botanic Garden, 1000 Lake Cook Road; Glencoe IL 60022 U.S.A
- Program in Plant Biology and Conservation; Northwestern University, 633 Clark Street; Evanston IL 60208 U.S.A
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Čertner M, Fenclová E, Kúr P, Kolář F, Koutecký P, Krahulcová A, Suda J. Evolutionary dynamics of mixed-ploidy populations in an annual herb: dispersal, local persistence and recurrent origins of polyploids. ANNALS OF BOTANY 2017; 120:303-315. [PMID: 28398545 PMCID: PMC5737363 DOI: 10.1093/aob/mcx032] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 03/08/2017] [Indexed: 05/18/2023]
Abstract
Background and Aims Despite the recent wealth of studies targeted at contact zones of cytotypes in various species, some aspects of polyploid evolution are still poorly understood. This is especially the case for the frequency and success rate of spontaneous neopolyploidization or the temporal dynamics of ploidy coexistence, requiring massive ploidy screening and repeated observations, respectively. To fill this gap, an extensive study of spatio-temporal patterns of ploidy coexistence was initiated in the widespread annual weed Tripleurospermum inodorum (Asteraceae). Methods DNA flow cytometry along with confirmatory chromosome counts was employed to assess ploidy levels of 11 018 adult individuals and 1263 ex situ germinated seedlings from 1209 Central European populations. The ploidy screening was conducted across three spatial scales and supplemented with observations of temporal development of 37 mixed-ploidy populations. Key Results The contact zone between the diploid and tetraploid cytotypes has a diffuse, mosaic-like structure enabling common cytotype coexistence from the within-population to the landscape level. A marked difference in monoploid genome size between the two cytotypes enabled the easy distinction of neotetraploid mutants from long-established tetraploids. Neotetraploids were extremely rare (0·03 %) and occurred solitarily. Altogether five ploidy levels (2 x -6 x ) and several aneuploids were discovered; the diversity in nuclear DNA content was highest in early ontogenetic stages (seedlings) and among individuals from mixed-ploidy populations. In spite of profound temporal oscillations in cytotype frequencies in mixed-ploidy populations, both diploids and tetraploids usually persisted up to the last census. Conclusions Diploids and tetraploids commonly coexist at all spatial scales and exhibit considerable temporal stability in local ploidy mixtures. Mixed-ploidy populations containing fertile triploid hybrids probaby act as effective generators of cytogenetic novelty and may facilitate inter-ploidy gene flow. Neopolyploid mutants were incapable of local establishment.
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Affiliation(s)
- Martin Čertner
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 00 Prague, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43 Průhonice, Czech Republic
| | - Eliška Fenclová
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 00 Prague, Czech Republic
| | - Pavel Kúr
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 00 Prague, Czech Republic
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 1760, CZ-370 05 České Budějovice, Czech Republic
| | - Filip Kolář
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 00 Prague, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43 Průhonice, Czech Republic
- National Centre for Biosystematics, Natural History Museum, University of Oslo, NO-0318 Oslo, Norway
| | - Petr Koutecký
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 1760, CZ-370 05 České Budějovice, Czech Republic
| | - Anna Krahulcová
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43 Průhonice, Czech Republic
| | - Jan Suda
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 00 Prague, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43 Průhonice, Czech Republic
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Barringer BC, Galloway LF. The Reproductive Ecology of Diploid and Tetraploid Galax urceolata. AMERICAN MIDLAND NATURALIST 2017. [DOI: 10.1674/0003-0031-177.2.299] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Brian C. Barringer
- Department of Biology, University of Wisconsin—Stevens Point, 800 Reserve Street, Stevens Point 54481
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Chrtek J, Herben T, Rosenbaumová R, Münzbergová Z, Dočkalová Z, Zahradníček J, Krejčíková J, Trávníček P. Cytotype coexistence in the field cannot be explained by inter-cytotype hybridization alone: linking experiments and computer simulations in the sexual species Pilosella echioides (Asteraceae). BMC Evol Biol 2017; 17:87. [PMID: 28335715 PMCID: PMC5364689 DOI: 10.1186/s12862-017-0934-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 03/10/2017] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Processes driving ploidal diversity at the population level are virtually unknown. Their identification should use a combination of large-scale screening of ploidy levels in the field, pairwise crossing experiments and mathematical modelling linking these two types of data. We applied this approach to determine the drivers of frequencies of coexisting cytotypes in mixed-ploidy field populations of the fully sexual plant species Pilosella echioides. We examined fecundity and ploidal diversity in seeds from all possible pairwise crosses among 2x, 3x and 4x plants. Using these data, we simulated the dynamics of theoretical panmictic populations of individuals whose progeny structure is identical to that determined by the hybridization experiment. RESULTS The seed set differed significantly between the crossing treatments, being highest in crosses between diploids and tetraploids and lowest in triploid-triploid crosses. The number of progeny classes (with respect to embryo and endosperm ploidy) ranged from three in the 2x-2x cross to eleven in the 3x-3x cross. Our simulations demonstrate that, provided there is no difference in clonal growth and/or survival between cytotypes, it is a clear case of minority cytotype exclusion depending on the initial conditions with two stable states, neither of which corresponds to the ploidal structure in the field: (i) with prevalent diploids and lower proportions of other ploidies, and (ii) with prevalent tetraploids and 9% of hexaploids. By contrast, if clonal growth differs between cytotypes, minority cytotype exclusion occurs only if the role of sexual reproduction is high; otherwise differences in clonal growth are sufficient to maintain triploid prevalence (as observed in the field) independently of initial conditions. CONCLUSIONS The projections of our model suggest that the ploidal structure observed in the field can only be reached via a relatively high capacity for clonal growth (and proportionally lower sexual reproduction) in all cytotypes combined with higher clonal growth in the prevailing cytotype (3x).
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Affiliation(s)
- Jindřich Chrtek
- Institute of Botany, The Czech Academy of Sciences, CZ-252 43 Průhonice, Czech Republic
- Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01 Prague, Czech Republic
| | - Tomáš Herben
- Institute of Botany, The Czech Academy of Sciences, CZ-252 43 Průhonice, Czech Republic
- Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01 Prague, Czech Republic
| | - Radka Rosenbaumová
- Department of Botany, Natural History Museum, National Museum, CZ-193 00 Prague – Horní Počernice, Czech Republic
| | - Zuzana Münzbergová
- Institute of Botany, The Czech Academy of Sciences, CZ-252 43 Průhonice, Czech Republic
- Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01 Prague, Czech Republic
| | - Zuzana Dočkalová
- Institute of Botany, The Czech Academy of Sciences, CZ-252 43 Průhonice, Czech Republic
| | - Jaroslav Zahradníček
- Institute of Botany, The Czech Academy of Sciences, CZ-252 43 Průhonice, Czech Republic
- Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01 Prague, Czech Republic
| | - Jana Krejčíková
- Institute of Botany, The Czech Academy of Sciences, CZ-252 43 Průhonice, Czech Republic
- Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01 Prague, Czech Republic
| | - Pavel Trávníček
- Institute of Botany, The Czech Academy of Sciences, CZ-252 43 Průhonice, Czech Republic
- Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01 Prague, Czech Republic
- Faculty of Agriculture, University of South Bohemia, CZ-370 05 České Budějovice, Czech Republic
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Zhang Y, Zhong C, Liu Y, Zhang Q, Sun X, Li D. Agronomic Trait Variations and Ploidy Differentiation of Kiwiberries in Northwest China: Implication for Breeding. FRONTIERS IN PLANT SCIENCE 2017; 8:711. [PMID: 28553297 PMCID: PMC5426280 DOI: 10.3389/fpls.2017.00711] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Accepted: 04/18/2017] [Indexed: 05/08/2023]
Abstract
Polyploid plants often have higher biomass and superior crop qualities. Breeders therefore search for crop germplasm with higher ploidy levels; however, whether higher ploidy levels are associated with better performance remains unclear. Actinidia arguta and related species, whose commercialized fruit are referred to as kiwiberries, harbor a series of ploidy races in nature, offering an opportunity to determine the link between ploidy levels and agronomic traits. In the present study, we determined the ploidy levels of A. arguta var. arguta, A. arguta var. giraldii, and A. melanandra in 16 natural populations using flow cytometry, and examined 31 trait variations in fruits, leaves and flowers by field observations, microscopic examination and laboratory analyses. Our results showed that octaploid and decaploid A. arguta var. giraldii had larger dimension of leaves than tetraploid A. arguta var. arguta and A. melanandra, but their fruits were significantly smaller. In addition, A. arguta var. giraldii (8x and 10x) had higher contents of nutrients such as ascorbic acid and amino acids; however, some important agronomic traits, including the content of total sugar and total acid, were significantly lower in the octaploids and decaploids. Moreover, octaploids and decaploids did not result in greater ecological adaptability for the challenging environments and climates. In conclusion, the differentiation of ecological adaptability and traits among natural kiwiberries' cytotypes suggested that higher ploidy levels are not inevitably advantageous in plants. The findings of A. arguta and related taxa in geographical distribution and agronomic trait variations will facilitate their germplasm domestication.
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Affiliation(s)
- Ying Zhang
- Xian Botanical Garden of Shaanxi Province, Botany Institution of Shaanxi ProvinceXian, China
| | - Caihong Zhong
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
| | - Yifei Liu
- South China Botanical Garden, Chinese Academy of SciencesGuangzhou, China
| | - Qiong Zhang
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
| | - Xiaorong Sun
- College of Horticulture, Shenyang Agricultural UniversityShenyang, China
| | - Dawei Li
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
- *Correspondence: Dawei Li
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Mandák B, Vít P, Krak K, Trávníček P, Havrdová A, Hadincová V, Zákravský P, Jarolímová V, Bacles CFE, Douda J. Flow cytometry, microsatellites and niche models reveal the origins and geographical structure of Alnus glutinosa populations in Europe. ANNALS OF BOTANY 2016; 117:107-20. [PMID: 26467247 PMCID: PMC4701152 DOI: 10.1093/aob/mcv158] [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: 01/08/2015] [Accepted: 09/01/2015] [Indexed: 05/11/2023]
Abstract
BACKGROUND AND AIMS Polyploidy in plants has been studied extensively. In many groups, two or more cytotypes represent separate biological entities with distinct distributions, histories and ecology. This study examines the distribution and origins of cytotypes of Alnus glutinosa in Europe, North Africa and western Asia. METHODS A combined approach was used involving flow cytometry and microsatellite analysis of 12 loci in 2200 plants from 209 populations combined with species distribution modelling using MIROC and CCSM climatic models, in order to analyse (1) ploidy and genetic variation, (2) the origin of tetraploid A. glutinosa, considering A. incana as a putative parent, and (3) past distributions of the species. KEY RESULTS The occurrence of tetraploid populations of A. glutinosa in Europe is determined for the first time. The distribution of tetraploids is far from random, forming two geographically well-delimited clusters located in the Iberian Peninsula and the Dinaric Alps. Based on microsatellite analysis, both tetraploid clusters are probably of autopolyploid origin, with no indication that A. incana was involved in their evolutionary history. A projection of the MIROC distribution model into the Last Glacial Maximum (LGM) showed that (1) populations occurring in the Iberian Peninsula and North Africa were probably interconnected during the LGM and (2) populations occurring in the Dinaric Alps did not exist throughout the last glacial periods, having retreated southwards into lowland areas of the Balkan Peninsula. CONCLUSIONS Newly discovered tetraploid populations are situated in the putative main glacial refugia, and neither of them was likely to have been involved in the colonization of central and northern Europe after glacial withdrawal. This could mean that neither the Iberian Peninsula nor the western part of the Balkan Peninsula served as effective refugial areas for northward post-glacial expansion of A. glutinosa.
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Affiliation(s)
- Bohumil Mandák
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic; Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6-Suchdol, CZ-165 21, Czech Republic;
| | - Petr Vít
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic; Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6-Suchdol, CZ-165 21, Czech Republic
| | - Karol Krak
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic; Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6-Suchdol, CZ-165 21, Czech Republic
| | - Pavel Trávníček
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic; Faculty of Agriculture, University of South Bohemia, Studentská 13, CZ-370 05, České Budějovice, Czech Republic and
| | - Alena Havrdová
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic; Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6-Suchdol, CZ-165 21, Czech Republic
| | - Věroslava Hadincová
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic
| | - Petr Zákravský
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic
| | - Vlasta Jarolímová
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic
| | - Cecile Fanny Emilie Bacles
- University of Pau and Pays Adour, UFR Sciences et Techniques, Departement de Biologie, F-64100 Pau, France
| | - Jan Douda
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic; Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6-Suchdol, CZ-165 21, Czech Republic
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Gross K, Schiestl FP. Are tetraploids more successful? Floral signals, reproductive success and floral isolation in mixed-ploidy populations of a terrestrial orchid. ANNALS OF BOTANY 2015; 115:263-73. [PMID: 25652914 PMCID: PMC4551083 DOI: 10.1093/aob/mcu244] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 10/07/2014] [Accepted: 10/22/2014] [Indexed: 05/11/2023]
Abstract
BACKGROUND AND AIMS Polyploidization, the doubling of chromosome sets, is common in angiosperms and has a range of evolutionary consequences. Newly formed polyploid lineages are reproductively isolated from their diploid progenitors due to triploid sterility, but also prone to extinction because compatible mating partners are rare. Models have suggested that assortative mating and increased reproductive fitness play a key role in the successful establishment and persistence of polyploids. However, little is known about these factors in natural mixed-ploidy populations. This study investigated floral traits that can affect pollinator attraction and efficiency, as well as reproductive success in diploid and tetraploid Gymnadenia conopsea (Orchidaceae) plants in two natural, mixed-ploidy populations. METHODS Ploidy levels were determined using flow cytometry, and flowering phenology and herbivory were also assessed. Reproductive success was determined by counting fruits and viable seeds of marked plants. Pollinator-mediated floral isolation was measured using experimental arrays, with pollen flow tracked by means of staining pollinia with histological dye. KEY RESULTS Tetraploids had larger floral displays and different floral scent bouquets than diploids, but cytotypes differed only slightly in floral colour. Significant floral isolation was found between the two cytotypes. Flowering phenology of the two cytotypes greatly overlapped, and herbivory did not differ between cytotypes or was lower in tetraploids. In addition, tetraploids had higher reproductive success compared with diploids. CONCLUSIONS The results suggest that floral isolation and increased reproductive success of polyploids may help to explain their successful persistence in mixed-ploidy populations. These factors might even initiate transformation of populations from pure diploid to pure tetraploid.
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Affiliation(s)
- Karin Gross
- Institute of Systematic Botany, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
| | - Florian P Schiestl
- Institute of Systematic Botany, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
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McAllister C, Blaine R, Kron P, Bennett B, Garrett H, Kidson J, Matzenbacher B, Glotzbach A, Miller AJ. Environmental correlates of cytotype distribution in Andropogon gerardii (Poaceae). AMERICAN JOURNAL OF BOTANY 2015; 102:92-102. [PMID: 25587152 DOI: 10.3732/ajb.1400296] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
UNLABELLED • PREMISE OF THE STUDY Information about geographic distribution of cytotypes can provide insight into the origin and maintenance of autopolyploid complexes and builds a foundation for understanding cytotype differentiation and the dynamics of mixed-ploidy populations. Here, we investigate environmental correlates of the geographic distributions of 6x and 9x individuals in the ecologically dominant grass Andropogon gerardii to examine the role of climate in shaping patterns of cytotype distribution in this species.• METHODS Flow cytometry was used to estimate ploidy level in 352 individuals from 32 populations across North America. Ecological differentiation of cytotypes was tested by relating BIOCLIM variables to cytotype distribution using principal components analysis and partial linear regression.• KEY RESULTS Broad geographic sampling confirmed two primary cytotypes-6x (hexaploid) and 9x (enneaploid)-and revealed that 9x plants are more common than previously thought. Enneaploids occur frequently in the southern portions of the range, with hexaploids dominating in northern regions. Mixed-ploidy populations were common (46.9%). Principal components analysis and partial linear regression indicated that reduced summer precipitation and increased variation in diurnal and seasonal temperature range were significant predictors of the frequency of 9x plants in a population.• CONCLUSIONS Results indicate that (1) geographic distribution of 6x and 9x individuals is nonrandom; (2) environmental variables are associated with cytotype distribution in A. gerardii; and (3) nearly half of populations surveyed include both 6x and 9x individuals. The persistence of mixed-ploidy populations may reflect a combination of recurrent polyploid formation and the prevalence of clonal reproduction.
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Affiliation(s)
- Christine McAllister
- Principia College, Department of Biology and Natural Resources, Elsah, Illinois 62028 USA Saint Louis University, Department of Biology, 3507 Macelwane Hall, St. Louis, Missouri 63103 USA
| | - Russell Blaine
- Southern Illinois University, Edwardsville, 1 Hairpin Drive, Edwardsville, Illinois 62025 USA
| | - Paul Kron
- University of Guelph, Department of Integrative Biology, 50 Stone Road East, Guelph, Ontario, Canada, NIG 2W1
| | - Brent Bennett
- Principia College, Department of Biology and Natural Resources, Elsah, Illinois 62028 USA
| | - Heidi Garrett
- Principia College, Department of Biology and Natural Resources, Elsah, Illinois 62028 USA
| | - Jennifer Kidson
- Principia College, Department of Biology and Natural Resources, Elsah, Illinois 62028 USA
| | - Blanda Matzenbacher
- Principia College, Department of Biology and Natural Resources, Elsah, Illinois 62028 USA
| | - Anna Glotzbach
- Principia College, Department of Biology and Natural Resources, Elsah, Illinois 62028 USA
| | - Allison J Miller
- Saint Louis University, Department of Biology, 3507 Macelwane Hall, St. Louis, Missouri 63103 USA
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Kumar P, Rana PK, Singhal VK, Gupta RC. Chromosome numbers, characterization of chromosomal pairing during meiosis, origin and natural propagation in polyploid cytotypes (4x, 5x and 6x) of Agrimonia eupatoria L. (Rosaceae) in northwest Himalayas (India). PROTOPLASMA 2014; 251:781-795. [PMID: 24318674 DOI: 10.1007/s00709-013-0581-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 10/29/2013] [Indexed: 06/02/2023]
Abstract
Despite the presence of intraspecific polyploidy (2x, 4x, 5x and 6x) in Agrimonia eupatoria, origin of these cytotypes has never been addressed adequately. The aim of the present study was to record the original chromosome counts and characterize chromosomal pairing during meiosis and microsporogenesis in the 5x cytotype, and discussing the hypothesis regarding the possible origin of polyploid cytotypes (4x, 5x and 6x) in the species. The geographical distribution pattern of cytotypes in the Indian Himalayas and elsewhere has also been analyzed. The present meiotic analysis revealed three chromosomes counts, the tetraploid (2n = 4x = 56), the pentaploid (2n = 5x = 70) and the hexaploid (2n = 6x = 84) cytotypes based on x = 14. Meiotic course was perfectly normal in the 4x and 6x cytotypes resulting into high pollen fertility (94-100 %). Meiotic course in the imbalanced 5x cytotype has been found to be irregular characterized by the presence of high frequency of univalents at diakinesis and metaphase-I. Abnormal meiotic course contributed towards high pollen sterility (74-88 %). Even the apparently fertile/stained pollen grains were of irregular shape and of heterogeneous sizes. Meiotic behaviour of the 5x cytotype is like typical of allopolyploid. Individuals of 5x cytotype did not produce seeds and propagate vegetatively (root suckers) while 4x and 6x cytotypes exploited sexual (seeds) as well as vegetative means for propagation. Chromosomal pairing in pentaploid cytotype is like typical of an allopolyploid and we assume that it might have originated owing to natural inter-cytotype hybridization between 4x and 6x cytotypes in a mixed population. Analysis of geographical distribution pattern of cytotypes shows that Indian Himalayas represent the most cytotype-diverse region for A. eupatoria with the existence of all the four cytotypes (2x, 4x, 5x, 6x). This shows the dynamic nature of the species at chromosomal level in this part of the world.
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Affiliation(s)
- Puneet Kumar
- Department of Botany, Punjabi University, Patiala, 147002, Punjab, India,
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Pico GMVD, Dematteis M. Cytotaxonomy of two species of genus Chrysolaena H. Robinson, 1988 (Vernonieae, Asteraceae) from Northeast Paraguay. COMPARATIVE CYTOGENETICS 2014; 8:125-37. [PMID: 25147624 PMCID: PMC4137283 DOI: 10.3897/compcytogen.v8i2.7209] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 04/15/2014] [Indexed: 06/03/2023]
Abstract
Chromosome counts and karyotypes of two species of Chrysolaena H. Robinson 1988 are presented in this paper. Mitotic analysis revealed that both taxa have x=10, a basic chromosome number considered characteristic of the genus. The chromosome number and the karyotype of Chrysolaena cristobaliana are reported for the first time, as well as a new cytotype and the karyotype of Chrysolaena sceptrum. Chrysolaena cristobaliana showed heptaploid cytotype with 2n=7x=70 and a karyotype composed of 46 m + 24 sm chromosomes. On the other hand, Chrysolaena sceptrum presented tetraploid cytotype with 2n=4x=40 and a karyotype with 30 m + 10 sm chromosomes. Accessory chromosomes were observed in cells of both species. The chromosome analysis showed that these species differ in the chromosome number and the total chromosome length, although they showed similar chromosome morphology and asymmetry indexes. The results support the use of chromosome data in taxonomic treatments of the American members of the tribe Vernonieae.
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Affiliation(s)
- Gisela M. Via Do Pico
- Instituto de Botánica del Nordeste (UNNE-CONICET), Sargento Cabral 2131. Casilla de Correo 209, CP 3400 Corrientes, Argentina
| | - Massimiliano Dematteis
- Instituto de Botánica del Nordeste (UNNE-CONICET), Sargento Cabral 2131. Casilla de Correo 209, CP 3400 Corrientes, Argentina
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Trávníček P, Jersáková J, Kubátová B, Krejčíková J, Bateman RM, Lučanová M, Krajníková E, Těšitelová T, Štípková Z, Amardeilh JP, Brzosko E, Jermakowicz E, Cabanne O, Durka W, Efimov P, Hedrén M, Hermosilla CE, Kreutz K, Kull T, Tali K, Marchand O, Rey M, Schiestl FP, Čurn V, Suda J. Minority cytotypes in European populations of the Gymnadenia conopsea complex (Orchidaceae) greatly increase intraspecific and intrapopulation diversity. ANNALS OF BOTANY 2012; 110:977-86. [PMID: 23002267 PMCID: PMC3448425 DOI: 10.1093/aob/mcs171] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 06/11/2012] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND AIMS Patterns of ploidy variation among and within populations can provide valuable insights into the evolutionary mechanisms shaping the dynamics of plant systems showing ploidy diversity. Whereas data on majority ploidies are, by definition, often sufficiently extensive, much less is known about the incidence and evolutionary role of minority cytotypes. METHODS Ploidy and proportions of endoreplicated genome were determined using DAPI (4',6-diamidino-2-phenylindole) flow cytometry in 6150 Gymnadenia plants (fragrant orchids) collected from 141 populations in 17 European countries. All widely recognized European species, and several taxa of less certain taxonomic status were sampled within Gymnadenia conopsea sensu lato. KEY RESULTS Most Gymnadenia populations were taxonomically and/or ploidy heterogeneous. Two majority (2x and 4x) and three minority (3x, 5x and 6x) cytotypes were identified. Evolution largely proceeded at the diploid level, whereas tetraploids were much more geographically and taxonomically restricted. Although minority ploidies constituted <2 % of the individuals sampled, they were found in 35 % of populations across the entire area investigated. The amount of nuclear DNA, together with the level of progressively partial endoreplication, separated all Gymnadenia species currently widely recognized in Europe. CONCLUSIONS Despite their low frequency, minority cytotypes substantially increase intraspecific and intrapopulation ploidy diversity estimates for fragrant orchids. The cytogenetic structure of Gymnadenia populations is remarkably dynamic and shaped by multiple evolutionary mechanisms, including both the ongoing production of unreduced gametes and heteroploid hybridization. Overall, it is likely that the level of ploidy heterogeneity experienced by most plant species/populations is currently underestimated; intensive sampling is necessary to obtain a holistic picture.
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Affiliation(s)
- Pavel Trávníček
- Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01 Prague, Czech Republic and Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43 Průhonice, Czech Republic
| | - Jana Jersáková
- Faculty of Science, University of South Bohemia in České Budějovice, CZ-370 05 České Budějovice, Czech Republic
| | - Barbora Kubátová
- Biotechnological Centre, Faculty of Agriculture, University of South Bohemia in České Budějovice, CZ-370 05 České Budějovice, Czech Republic
| | - Jana Krejčíková
- Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01 Prague, Czech Republic and Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43 Průhonice, Czech Republic
| | | | - Magdalena Lučanová
- Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01 Prague, Czech Republic and Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43 Průhonice, Czech Republic
| | - Eva Krajníková
- Biotechnological Centre, Faculty of Agriculture, University of South Bohemia in České Budějovice, CZ-370 05 České Budějovice, Czech Republic
| | - Tamara Těšitelová
- Faculty of Science, University of South Bohemia in České Budějovice, CZ-370 05 České Budějovice, Czech Republic
| | - Zuzana Štípková
- Faculty of Science, University of South Bohemia in České Budějovice, CZ-370 05 České Budějovice, Czech Republic
| | | | - Emilia Brzosko
- Institute of Biology, University of Bialystok, Świerkowa 20B, PL-15-950 Bialystok, Poland
| | - Edyta Jermakowicz
- Institute of Biology, University of Bialystok, Świerkowa 20B, PL-15-950 Bialystok, Poland
| | | | - Walter Durka
- Helmholtz Centre for Environmental Research–UFZ, Department of Community Ecology, Theodor-Lieser-Str. 4, D-06120 Halle, Germany
| | - Peter Efimov
- Herbarium, Komarov Botanical Institute of Russian Academy of Sciences, Prof. Popov str. 2, 197376 Saint-Petersburg, Russia
| | - Mikael Hedrén
- Department of Biology, University of Lund, Solvegatan 37, SE-22362 Lund, Sweden
| | | | - Karel Kreutz
- Oude Landgraaf 35a, NL-6373 Landgraaf, The Netherlands
| | - Tiiu Kull
- Department of Botany, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 5, EE-51014 Tartu, Estonia
| | - Kadri Tali
- Department of Botany, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 5, EE-51014 Tartu, Estonia
| | | | - Manel Rey
- Institute of Systematic Botany, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | - Florian P. Schiestl
- Institute of Systematic Botany, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | - Vladislav Čurn
- Biotechnological Centre, Faculty of Agriculture, University of South Bohemia in České Budějovice, CZ-370 05 České Budějovice, Czech Republic
| | - Jan Suda
- Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01 Prague, Czech Republic and Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43 Průhonice, Czech Republic
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Abstract
The prevalence of polyploidy among flowering plants is surprising given the hurdles impeding the establishment and persistence of novel polyploid lineages. In the absence of strong assortative mating, reproductive assurance, or large intrinsic fitness advantages, new polyploid lineages face almost certain extinction through minority cytotype exclusion. Consequently, much work has focused on a search for adaptive advantages associated with polyploidy such as increased competitive ability, enhanced ecological tolerances, and increased resistance to pathogens. Yet, no consistent adaptive advantages of polyploidy have been identified. Here, to investigate the potential for autopolyploid establishment and persistence in the absence of any intrinsic fitness advantages, we develop a simulation model of a diploid population that sporadically gives rise to novel autopolyploids. The autopolyploids have only very small levels of initial assortative mating or niche differentiation, generated entirely by dosage effects of genome duplication, and they have realistic levels of reproductive assurance. Our results show that by allowing assortative mating and competitive interactions to evolve, establishment of novel autopolyploid lineages becomes common. Additional scenarios where adaptive optima change over time reveal that rapid environmental change promotes the replacement of diploid lineages by their autopolyploid descendants. These results help to explain recent empirical findings that suggest that many contemporary polyploid lineages arose during the Cretaceous-Tertiary extinction, without invoking adaptive advantages of polyploidy.
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Affiliation(s)
- Benjamin P. Oswald
- Bioinformatics and Computational Biology, University of Idaho, Moscow ID 83844
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Richardson ML, Hanks LM. Differences in spatial distribution, morphology, and communities of herbivorous insects among three cytotypes of Solidago altissima (Asteraceae). AMERICAN JOURNAL OF BOTANY 2011; 98:1595-1601. [PMID: 21926306 DOI: 10.3732/ajb.1100018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
PREMISE OF THE STUDY Polyploidy in plants can result in genetic isolation, ecological differences among cytotypes, and, ultimately, speciation. Cytotypes should be sympatric only if they are segregated in an ecological niche or through prezygotic isolation. We tested whether sympatric diploid, tetraploid, and hexaploid ramets of Solidago altissima L. (Asteraceae) differ in their ecological niche. METHODS We measured how cytotypes were distributed within habitats, their morphology, and the composition of their communities of herbivorous insects at 10 natural field sites. We also conducted a common garden experiment to confirm whether observed differences in morphology or communities of herbivores were due to cytotype or environmental effects. KEY RESULTS Diploid ramets often grew in open areas, relatively far from woody plants, and were associated with a high species richness of herbaceous plants, especially grasses. Hexaploids often grew in heavy shading under woody plants where grasses were scarce. Finally, tetraploids usually grew in transition areas between diploids and hexaploids. Hexaploid ramets also were taller than ramets of the other cytotypes and had larger leaves. Two species of insects, the leaf-galling fly Asteromyia carbonifera and the phloem-tapping aphid Uroleucon nigrotuberculatum, were more abundant on hexaploid ramets than on ramets of other cytotypes in the field. When grown in a common garden, however, cytotypes were similar in morphology and communities of herbivores. CONCLUSIONS We conclude that cytotypes of S. altissima differ in their spatial distribution within habitats and that spatial variation in environmental factors influence plant morphology and communities of herbivorous insects.
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Affiliation(s)
- Matthew L Richardson
- Program in Ecology, Evolution, and Conservation Biology, University of Illinois at Urbana-Champaign, 61801, USA
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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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Neiman M, Paczesniak D, Soper DM, Baldwin AT, Hehman G. Wide variation in ploidy level and genome size in a New Zealand freshwater snail with coexisting sexual and asexual lineages. Evolution 2011; 65:3202-16. [PMID: 22023586 DOI: 10.1111/j.1558-5646.2011.01360.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Natural animal populations are rarely screened for ploidy-level variation at a scale that allows detection of potentially important aberrations of common ploidy patterns. This type of screening can be especially important for the many mixed sexual/asexual systems in which sexuals are presumed to be dioecious diploids and asexuals are assumed to be triploid and all-female. For example, elevation of ploidy level above triploidy can be a source of genetic variation and raises the possibility of gene flow among ploidy levels and to asexual lineages. We used flow cytometry and mtDNA sequencing to characterize ploidy level and genome size in Potamopyrgus antipodarum, a New Zealand freshwater snail where obligate sexual (presumed diploid and dioecious) and obligate apomictic asexual (presumed triploid and nearly all female) individuals frequently coexist. We documented the widespread occurrence and multiple origins of polyploid males and individuals with >3× ploidy, and find that both are likely to be descended from asexual females. Our survey also suggested the existence of extensive variation in genome size. The discovery of widespread variation in ploidy level and genome size in such a well-studied system highlights the importance of broad, extensive, and ecologically representative sampling in uncovering ploidy level and genome-size variation in natural populations.
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Affiliation(s)
- Maurine Neiman
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA.
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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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Duchoslav M, Šafářová L, Krahulec F. Complex distribution patterns, ecology and coexistence of ploidy levels of Allium oleraceum (Alliaceae) in the Czech Republic. ANNALS OF BOTANY 2010; 105:719-35. [PMID: 20363760 PMCID: PMC2859911 DOI: 10.1093/aob/mcq035] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 10/05/2009] [Accepted: 01/21/2010] [Indexed: 05/19/2023]
Abstract
BACKGROUND AND AIMS Despite extensive study of polyploidy, its origin, and ecogeographical differences between polyploids and their diploid progenitors, few studies have addressed ploidy-level structure and patterns of ecogeographical differentiation at various spatial scales using detailed sampling procedures. The pattern of coexistence of polyploids in the geophyte Allium oleraceum at the landscape and locality scale and their ecology were studied. METHODS Flow cytometry and root-tip squashes were used to identify the ploidy level of 4347 plants from 325 populations sampled from the Czech Republic using a stratified random sampling procedure. Ecological differentiation among ploidy levels was tested by comparing sets of environmental variables recorded at each locality. KEY RESULTS Across the entire sampling area, pentaploids (2n = 5x = 40) predominated, while hexaploids (2n = 6x = 48) and tetraploids (2n = 4x = 32) were less frequent. The distribution of tetra- and hexaploids was partially sympatric (in the eastern part) to parapatric (in the western part of the Czech Republic) whereas pentaploids were sympatric with other cytotypes. Plants of different ploidy levels were found to be ecologically differentiated and the ruderal character of cytotypes increased in the direction 4x --> 5x --> 6x with the largest realized niche differences between tetra- and hexaploids. Most populations contained only one ploidy level (77 %), 22 % had two (all possible combinations) and 1 % were composed of three ploidy levels. The majority of 4x + 5x and 5x + 6x mixed populations occurred in sympatry with uniform populations of the participating cytotypes in sites with ecologically heterogeneous or marginal environment, suggesting secondary contact between cytotypes. Some mixed 4x + 6x populations dominated by tetraploids being sympatric and intermixed with uniform 4x populations might represent primary zones of cytotype contact. Almost no mixed accessions were observed on the fine spatial scale in mixed populations. CONCLUSIONS The results provide evidence for adaptive differences among ploidy levels, which may contribute to their complex distribution pattern. The prevalence of asexual reproduction, limited dispersal and equilibrium-disrupting processes may support local coexistence of cytotypes.
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Affiliation(s)
- Martin Duchoslav
- Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc, Czech Republic
| | - Lenka Šafářová
- Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc, Czech Republic
| | - František Krahulec
- Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43 Průhonice, Czech Republic
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Abstract
Autopolyploidy is more common in plants than traditionally assumed, but has received little attention compared with allopolyploidy. Hence, the advantages and disadvantages of genome doubling per se compared with genome doubling coupled with hybridizations in allopolyploids remain unclear. Autopolyploids are characterized by genomic redundancy and polysomic inheritance, increasing effective population size. To shed light on the evolutionary consequences of autopolyploidy, we review a broad range of studies focusing on both synthetic and natural autopolyploids encompassing levels of biological organization from genes to evolutionary lineages. The limited evidence currently available suggests that autopolyploids neither experience strong genome restructuring nor wide reorganization of gene expression during the first generations following genome doubling, but that these processes may become more important in the longer term. Biogeographic and ecological surveys point to an association between the formation of autopolyploid lineages and environmental change. We thus hypothesize that polysomic inheritance may provide a short-term evolutionary advantage for autopolyploids compared to diploid relatives when environmental change enforces range shifts. In addition, autopolyploids should possess increased genome flexibility, allowing them to adapt and persist across heterogeneous landscapes in the long run.
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Affiliation(s)
- Christian Parisod
- National Centre for Biosystematics, University of Oslo, 0318 Oslo, Norway.
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Raabová J, Fischer M, Münzbergová Z. Niche differentiation between diploid and hexaploid Aster amellus. Oecologia 2008; 158:463-72. [DOI: 10.1007/s00442-008-1156-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Accepted: 09/08/2008] [Indexed: 10/21/2022]
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BRETAGNOLLE FRANÇOIS. Pollen production and spontaneous polyploidization in diploid populations of Anthoxanthum alpinum. Biol J Linn Soc Lond 2008. [DOI: 10.1111/j.1095-8312.2001.tb01314.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kron P, Suda J, Husband BC. Applications of Flow Cytometry to Evolutionary and Population Biology. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2007. [DOI: 10.1146/annurev.ecolsys.38.091206.095504] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Paul Kron
- Department of Integrative Biology, University of Guelph, Ontario, Canada N1G 2W1; ,
| | - Jan Suda
- Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01, Czech Republic and Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43, Czech Republic;
| | - Brian C. Husband
- Department of Integrative Biology, University of Guelph, Ontario, Canada N1G 2W1; ,
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Talent N, Dickinson TA. Endosperm formation in aposporous Crataegus (Rosaceae, Spiraeoideae, tribe Pyreae): parallels to Ranunculaceae and Poaceae. THE NEW PHYTOLOGIST 2007; 173:231-49. [PMID: 17204072 DOI: 10.1111/j.1469-8137.2006.01918.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Apomixis in Crataegus is primarily aposporous and requires pollination. The embryo sac is of the Polygonum type. A combination of meiotically unreduced embryo sacs with apparently reduced pollen would violate the usual requirement for a 2 : 1 ratio of maternal to paternal contributions to the endosperm. We therefore investigated the origin of endosperm in seeds of sexual diploids and apomictic polyploids of the sister genera Crataegus and Mespilus. Flow-cytometric DNA measurements from embryo and endosperm in mature seeds were converted to ploidy levels using leaf-tissue information. The diploids had triploid endosperm. In c. 60% of seed from polyploids, one sperm apparently contributes to the endosperm, while 25% or more may involve two sperm. Additional results suggest that trinucleate central cells also occur. Fertilization of meiotically unreduced eggs is indicated. The ratio of maternal to paternal contributions to the endosperm in these apomictic Crataegus is not constrained to 2 : 1. They thus resemble some Sorbus (Pyreae) and very distantly related Ranunculus (Ranunculaceae). It is suggested that Paspalum (Poaceae) may have similarly flexible endosperm ploidy levels.
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Affiliation(s)
- Nadia Talent
- Department of Botany, University of Toronto, 25 Willcocks Street, Toronto, ON, Canada M5S 3B2.
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Galloway LF, Etterson JR. Inbreeding depression in an autotetraploid herb: a three cohort field study. THE NEW PHYTOLOGIST 2007; 173:383-92. [PMID: 17204084 DOI: 10.1111/j.1469-8137.2006.01909.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Autotetraploids are predicted to have reduced inbreeding depression relative to diploids. However, recent theory and information on genomic changes following autopolyploidy suggest that inbreeding depression may be closer to diploids. In three consecutive years, self and outcross pollinations were conducted on autotetraploid Campanulastrum americanum, seeds were planted into native sites, and biennial offspring were followed through seed production. Inbred individuals had lower germination rates, reduced survival, were smaller, and flowered later, producing fewer fruits with fewer seeds. Inbred offspring had 6% of the cumulative fitness of outcross offspring. Although performance varied substantially among cohorts, inbreeding depression for cumulative fitness was relatively constant, with delta ranging only from 0.92 to 0.95. C. americanum, like many outcrossing species, expressed very high amounts of inbreeding depression. This supports the hypothesis that inbreeding depression of some autotetraploids may be similar to that of diploids. Furthermore, few studies have measured temporal variation in inbreeding depression. Constant inbreeding depression given a sixfold range in cohort performance suggests that inbreeding depression may be relatively robust to environmental variation experienced by natural populations.
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Affiliation(s)
- Laura F Galloway
- Department of Biology, University of Virginia, Charlottesville, VA 22904-4328, USA.
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Mandáková T, Münzbergová Z. Distribution and ecology of cytotypes of the Aster amellus aggregates in the Czech Republic. ANNALS OF BOTANY 2006; 98:845-56. [PMID: 16870643 PMCID: PMC2806165 DOI: 10.1093/aob/mcl165] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Revised: 02/24/2006] [Accepted: 06/05/2006] [Indexed: 05/11/2023]
Abstract
BACKGROUND AND AIMS Polyploidy is viewed as an important mechanism of sympatric speciation, but only a few studies have documented patterns of distribution and ecology of different cytotypes in their contact zone. Aster amellus agg. (Asteraceae) is one of the species with documented multiple ploidy levels. The aim of this study was to determine spatial distribution and ecology of two cytotypes, diploid (2n = 18) and hexaploid (2n = 54), of Aster amellus agg. at their contact zone in the Czech Republic. METHODS Root-tip squashes and flow cytometry were used to determine the ploidy of 2175 individuals from 87 populations. To test whether some differences in ecology between the two ploidy levels exist, in each locality relevés were recorded and abiotic conditions of the sites were studied by estimating potential direct solar radiation, Ellenberg indicator values and above-ground biomass. KEY RESULTS Together with diploid and hexaploids, minorite cytotypes (triploid, pentaploid and nonaploid) were found. No significant ecological differences between diploid and hexaploid cytotypes were found. In spite of this, no population consisting of both of the two basic cytotypes was found. CONCLUSIONS The results of this study show that the contact zone of diploid and hexaploid cytotypes in the Czech Republic is much more diffuse than indicated in previous records. Although populations of both cytotypes occur in close proximity (the closest populations of different cytotypes were 500 m apart), each individual population consists of only one basic ploidy level. This was unexpected since there are no clear differences in abiotic conditions between populations. Taken together with the absence of an intermediate tetraploid cytotype and with reference to published world distributional patterns of different ploidy levels, this suggests a secondary contact zone. Detailed genetic study is, however, necessary to confirm this.
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Affiliation(s)
- Terezie Mandáková
- Department of Botany, Charles University, Benátská 2, CZ-128 01, Prague, Czech Republic.
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Talent N, Dickinson TA. Polyploidy inCrataegusandMespilus(Rosaceae, Maloideae): evolutionary inferences from flow cytometry of nuclear DNA amounts. ACTA ACUST UNITED AC 2005. [DOI: 10.1139/b05-088] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hawthorns and medlars are closely related genera in Rosaceae subfamily Maloideae, whose taxonomy remains poorly understood. Gametophytic apomixis occurs in polyploids, and diploids are sexual out-crossers, so ploidy level is of great interest, but suitable material for chromosome counts is of limited availability each year. The promise of flow cytometry is that it permits rapid measurement of nuclear DNA amounts from most tissues, and ploidy level can be inferred if climatic and taxonomic differences do not interfere. Our DNA measurements cover most of the taxonomic series in Crataegus , adding cultivated and naturalized Eurasian plants to the many wild plants collected mainly from south-central Canada and the southeastern and northwestern United States. We found that some variation in DNA amount per genome copy distinguishes certain taxa, but ploidy-level estimates are at least as clear as the published chromosome counts, especially in the most common diploid–triploid–tetraploid range, and to the single published higher (hexaploid) chromosome count, we add evidence of pentaploids. By comparing ploidy evaluations to morphology, we hypothesize that both autopolyploidy and allopolyploidy contribute to the taxonomic complexity. We compared DNA amounts in Maloideae with those in Gillenia , a likely sister genus to the subfamily, which has a smaller chromosome number.
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Affiliation(s)
- Nadia Talent
- Department of Botany, University of Toronto, 25 Willcocks Street, Toronto, ON M5S 3B2, Canada
- Center for Biodiversity and Conservation Biology, Royal Ontario Museum, 100 Queen's Park West, Toronto, ON M5S 2C6, Canada
| | - Timothy A. Dickinson
- Department of Botany, University of Toronto, 25 Willcocks Street, Toronto, ON M5S 3B2, Canada
- Center for Biodiversity and Conservation Biology, Royal Ontario Museum, 100 Queen's Park West, Toronto, ON M5S 2C6, Canada
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Rausch JH, Morgan MT. THE EFFECT OF SELF-FERTILIZATION, INBREEDING DEPRESSION, AND POPULATION SIZE ON AUTOPOLYPLOID ESTABLISHMENT. Evolution 2005. [DOI: 10.1554/05-095.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Yeung K, Miller JS, Savage AE, Husband BC, Igic B, Kohn JR. ASSOCIATION OF PLOIDY AND SEXUAL SYSTEM IN LYCIUM CALIFORNICUM (SOLANACEAE). Evolution 2005. [DOI: 10.1554/05-354.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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HUSBAND BRIANC. The role of triploid hybrids in the evolutionary dynamics of mixed-ploidy populations. Biol J Linn Soc Lond 2004. [DOI: 10.1111/j.1095-8312.2004.00339.x] [Citation(s) in RCA: 199] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Li BH, Xu XM, Ridout MS. Modelling the establishment and spread of autotetraploid plants in a spatially heterogeneous environment. J Evol Biol 2004; 17:562-73. [PMID: 15149399 DOI: 10.1111/j.1420-9101.2004.00700.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The establishment and spread of autotetraploids from an original diploid population in a heterogeneous environment were studied using a stochastic simulation model. Specifically, we investigated the effects of heterogeneous habitats and nonrandom pollen/seed dispersal on the critical value (micro) of unreduced 2n gamete production necessary for the establishment of autotetraploids as predicted by deterministic models. Introduction of a heterogeneous environment with random pollen/seed dispersal had little effect on the micro value. In contrast, incorporating nonrandom pollen/seed dispersal into a homogeneous environment considerably reduced the micro value. Incorporating both heterogeneous habitats and nonrandom pollen/seed dispersal may lead either to an increase or to a decrease in the micro value compared to that with random dispersal, indicating that the two factors interact in a complex way.
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Affiliation(s)
- B-H Li
- Horticulture Research International, East Malling, West Malling, Kent, UK
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Stuessy TF, Weiss-Schneeweiss H, Keil DJ. Diploid and polyploid cytotype distribution in Melampodium cinereum and M. leucanthum (Asteraceae, Heliantheae). AMERICAN JOURNAL OF BOTANY 2004; 91:889-98. [PMID: 21653445 DOI: 10.3732/ajb.91.6.889] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Previous chromosomal studies within Melampodium (Asteraceae, Heliantheae) of Mexico and Central America have documented chromosome numbers n = 9, 10, 11, 12, 18, 20, 23, 25 ± 1, 27, 30, and 33. Some species also have been shown to exhibit infra- and interpopulational polyploidy. The presence of cytotype mixtures is especially pronounced in the white-rayed complex, which occurs in the southwestern United States and adjacent Mexico. This group includes M. cinereum (n = 10 and 20), M. leucanthum (n = 10 and 20), and M. argophyllum (n = 30). Cytotype distribution has been newly analyzed in 415 plants from 152 populations and added to existing data from 185 plants from 113 populations, yielding information from a total of 600 individuals from 265 populations. Within M. cinereum and M. leucanthum are parapatric distributions of cytotypes, with tetraploids centered in the eastern and diploids in the western portions of their ranges. Tetraploids are most likely of autopolyploid origin, forming recurrently, with adaptations that allow colonization and establishment in new ecological regions. Contact zones are relatively narrow and only two triploid individuals have been detected. The tetraploid cytotypes probably extended eastward into central and southern Texas to the natural barriers at the edge of the Edward's Plateau in M. leucanthum and the low sandy plains in M. cinereum. The hexaploid M. argophyllum is interpreted as a relict surviving in the low mountains of northern Mexico; it may be an allopolyploid of hybrid origin between ancestors of the evolutionary lines that eventually yielded M. cinereum and M. leucanthum.
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Affiliation(s)
- Tod F Stuessy
- Department of Higher Plant Systematics and Evolution, Institute of Botany, University of Vienna, Rennweg 14,A-1030 Vienna, Austria
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Husband BC, Schemske DW, Burton TL, Goodwillie C. Pollen competition as a unilateral reproductive barrier between sympatric diploid and tetraploid Chamerion angustifolium. Proc Biol Sci 2002; 269:2565-71. [PMID: 12573071 PMCID: PMC1691195 DOI: 10.1098/rspb.2002.2196] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Speciation requires the evolution of barriers to gene exchange between descendant and progenitor populations. Cryptic reproductive barriers in plants arise after pollination but before fertilization as a result of pollen competition and interactions between male gametophytes and female reproductive tissues. We tested for such gametic isolation between the polyploid Chamerion angustifolium and its diploid progenitor by conducting single (diploid or tetraploid) and mixed ploidy (1 : 1 diploid and tetraploid) pollinations on both cytotypes and inferring siring success from paternity analysis and pollen-tube counts. In mixed pollinations, polyploids sired most (79%) of their own seeds as well as those of diploids (61%) (correcting for triploid block, siring success was 70% and 83%, respectively). In single donor pollinations, pollen tubes from tetraploids were more numerous than those from diploids at four different positions in each style and for both diploid and tetraploid pollen recipients. The lack of a pollen donor x recipient interaction indicates that the tetraploid siring advantage is a result of pollen competition rather than pollen-pistil interactions. Such unilateral pollen precedence results in an asymmetrical pattern of isolation, with tetraploids experiencing less gene flow than diploids. It also enhances tetraploid establishment in sympatric populations, by maximizing tetraploid success and simultaneously diminishing that of diploids through the production of inviable triploid offspring.
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Affiliation(s)
- Brian C Husband
- Department of Botany, University of Guelph, Guelph, ON, N1G 2W1, Canada.
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Abstract
Changes in ploidy occurred early in the diversification of some animal and plant lineages and represent an ongoing phenomenon in others. While the prevalence of polyploid lineages indicates that this phenomenon is a common and successful evolutionary transition, whether polyploidization itself has a significant effect on patterns and rates of diversification remains an open question. Here we review evidence for the creative role of polyploidy in evolution. We present new estimates for the incidence of polyploidy in ferns and flowering plants based on a simple model describing transitions between odd and even base chromosome numbers. These new estimates indicate that ploidy changes may represent from 2 to 4% of speciation events in flowering plants and 7% in ferns. Speciation via polyploidy is likely to be one of the more predominant modes of sympatric speciation in plants, owing to its potentially broad-scale effects on gene regulation and developmental processes, effects that can produce immediate shifts in morphology, breeding system, and ecological tolerances. Theoretical models support the potential for increased adaptability in polyploid lineages. The evidence suggests that polyploidization can produce shifts in genetic systems and phenotypes that have the potential to result in increased evolutionary diversification, yet conclusive evidence that polyploidy has changed rates and patterns of diversification remains elusive.
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Affiliation(s)
- S P Otto
- Department of Zoology and Department of Botany, University of British Columbia, Vancouver BC V6T 1Z4 Canada.
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Burton TL, Husband BC. FITNESS DIFFERENCES AMONG DIPLOIDS, TETRAPLOIDS, AND THEIR TRIPLOID PROGENY IN CHAMERION ANGUSTIFOLIUM: MECHANISMS OF INVIABILITY AND IMPLICATIONS FOR POLYPLOID EVOLUTION. Evolution 2000. [DOI: 10.1554/0014-3820(2000)054[1182:fdadta]2.0.co;2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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