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Morphological Continua Make Poor Species: Genus-Wide Morphometric Survey of the European Bee Orchids ( Ophrys L.). BIOLOGY 2023; 12:biology12010136. [PMID: 36671828 PMCID: PMC9855528 DOI: 10.3390/biology12010136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/03/2023] [Accepted: 01/09/2023] [Indexed: 01/17/2023]
Abstract
Despite (or perhaps because of) intensive multidisciplinary research, opinions on the optimal number of species recognised within the Eurasian orchid genus Ophrys range from nine to at least 400. The lower figure of nine macrospecies is based primarily on seeking small but reliable discontinuities in DNA 'barcode' regions, an approach subsequently reinforced and finessed via high-throughput sequencing studies. The upper figure of ca. 400 microspecies reflects the morphological authoritarianism of traditional taxonomy combined with belief in extreme pollinator specificity caused by reliance on pollination through pseudo-copulation, enacted by bees and wasps. Groupings of microspecies that are less inclusive than macrospecies are termed mesospecies. Herein, we present multivariate morphometric analyses based on 51 characters scored for 457 individual plants that together span the full morphological and molecular diversity within the genus Ophrys, encompassing 113 named microspecies that collectively represent all 29 mesospecies and all nine macrospecies. We critique our preferred morphometric approach of accumulating heterogeneous data and analysing them primarily using principal coordinates, noting that our conclusions would have been strengthened by even greater sampling and the inclusion of data describing pseudo-pheromone cocktails. Morphological variation within Ophrys proved to be exceptionally multidimensional, lacking strong directional trends. Multivariate clustering of plants according to prior taxonomy was typically weak, irrespective of whether it was assessed at the level of macrospecies, mesospecies or microspecies; considerable morphological overlap was evident even between subsets of the molecularly differentiable macrospecies. Characters supporting genuine taxonomic distinctions were often sufficiently subtle that they were masked by greater and more positively correlated variation that reflected strong contrasts in flower size, tepal colour or, less often, plant size. Individual macrospecies appear to represent morphological continua, within which taxonomic divisions are likely to prove arbitrary if based exclusively on morphological criteria and adequately sampled across their geographic range. It remains unclear how much of the mosaic of subtle character variation among the microspecies reflects genetic versus epigenetic or non-genetic influences and what proportion of any contrasts observed in gene frequencies can be attributed to the adaptive microevolution that is widely considered to dictate speciation in the genus. Moreover, supplementing weak morphological criteria with extrinsic criteria, typically by imposing constraints on geographic location and/or supposed pollinator preference, assumes rather than demonstrates the presence of even the weakest of species boundaries. Overall, it is clear that entities in Ophrys below the level of macrospecies have insufficiently structured variation, either phenotypic or genotypic, to be resolved into discrete, self-circumscribing ("natural") entities that can legitimately be equated with species as delimited within other less specialised plant genera. Our search for a non-arbitrary (meso)species concept competent to circumscribe an intermediate number of species has so far proven unsuccessful.
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Bateman RM, Rudall PJ, Murphy ARM, Cowan RS, Devey DS, Peréz-Escobar OA. Whole plastomes are not enough: phylogenomic and morphometric exploration at multiple demographic levels of the bee orchid clade Ophrys sect. Sphegodes. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:654-681. [PMID: 33449086 DOI: 10.1093/jxb/eraa467] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 12/15/2020] [Indexed: 05/21/2023]
Abstract
Plastid sequences have long dominated phylogeny reconstruction at all time depths, predicated on a usually untested assumption that they accurately represent the evolutionary histories of phenotypically circumscribed species. We combined detailed in situ morphometrics (124 plants) and whole-plastome sequencing through genome skimming (71 plants) in order to better understand species-level diversity and speciation in arguably the most challenging monophyletic group within the taxonomically controversial, pseudo-copulatory bee orchid genus Ophrys. Using trees and ordinations, we interpreted the data at four nested demographic levels-macrospecies, mesospecies, microspecies, and local population-seeking the optimal level for bona fide species. Neither morphological nor molecular discontinuities are evident at any level below macrospecies, the observed overlap among taxa suggesting that both mesospecies and microspecies reflect arbitrary division of a continuum of variation. Plastomes represent geographic location more strongly than taxonomic assignment and correlate poorly with morphology, suggesting widespread plastid capture and possibly post-glacial expansion from multiple southern refugia. As they are rarely directly involved in the speciation process, plastomes depend on extinction of intermediate lineages to provide phylogenetic signal and so cannot adequately document evolutionary radiations. The popular 'ethological' evolutionary model recognizes as numerous 'ecological species' (microspecies) lineages perceived as actively diverging as a result of density-dependent selection on very few features that immediately dictate extreme pollinator specificity. However, it is assumed rather than demonstrated that the many microspecies are genuinely diverging. We conversely envisage a complex four-dimensional reticulate network of lineages, generated locally and transiently through a wide spectrum of mechanisms, but each unlikely to maintain an independent evolutionary trajectory long enough to genuinely speciate by escaping ongoing gene flow. The frequent but localized microevolution that characterizes the Ophrys sphegodes complex is often convergent and rarely leads to macroevolution. Choosing between the contrasting 'discontinuity' and 'ethology' models will require next-generation sequencing of nuclear genomes plus ordination of corresponding morphometric matrices, seeking the crucial distinction between retained ancestral polymorphism-consistent with lineage divergence-and polymorphisms reflecting gene flow through 'hybridization'-more consistent with lineage convergence.
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Tsiftsis S. The complex effect of heterogeneity and isolation in determining alpha and beta orchid diversity on islands in the Aegean archipelago. SYST BIODIVERS 2020. [DOI: 10.1080/14772000.2020.1738584] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Spyros Tsiftsis
- Department of Forestry and Natural Environment, International Hellenic University, Drama, GR-66100, Greece
- Global Change Research Institute, Academy of Science of the Czech Republic, Belidla 4a, Brno, 603, Czech Republic
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Jin WT, Schuiteman A, Chase MW, Li JW, Chung SW, Hsu TC, Jin XH. Phylogenetics of subtribe Orchidinae s.l. (Orchidaceae; Orchidoideae) based on seven markers (plastid matK, psaB, rbcL, trnL-F, trnH-psba, and nuclear nrITS, Xdh): implications for generic delimitation. BMC PLANT BIOLOGY 2017; 17:222. [PMID: 29178835 PMCID: PMC5702240 DOI: 10.1186/s12870-017-1160-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 11/08/2017] [Indexed: 05/13/2023]
Abstract
BACKGROUND Subtribe Orchidinae (Orchidaceae, Orchidoideae) are a nearly cosmopolitan taxon of terrestrial orchids, comprising about 1800 species in 47 to 60 genera. Although much progress has been made in recent years of phylogenetics of Orchidinae, considerable problems remain to be addressed. Based on molecular phylogenetics, we attempt to illustrate the phylogenetic relationships and discuss generic delimitation within Orchidinae. Seven DNA markers (five plastid and two nuclear), a broad sampling of Orchidinae (400 species in 52 genera) and three methods of phylogenetic analysis (maximum likelihood, maximum parsimony and Bayesian inference) were used. RESULTS Orchidinae s.l. are monophyletic. Satyrium is sister to the rest of Orchidinae s.l. Brachycorythis and Schizochilus are successive sister to Asian-European Orchidinae s.s. Sirindhornia and Shizhenia are successive sister to clade formed by Tsaiorchis-Hemipilia-Ponerorchis alliance. Stenoglottis is sister to the Habenaria-Herminium-Peristylus alliance. Habenaria, currently the largest genus in Orchidinae, is polyphyletic and split into two distant clades: one Asian-Australian and the other African-American-Asian. Diplomeris is sister to Herminium s.l. plus Asian-Australian Habenaria. CONCLUSIONS We propose to recognize five genera in the Ponerorchis alliance: Hemipilia, Ponerorchis s.l., Sirindhornia, Shizhenia and Tsaiorchis. Splitting Habenaria into two genera based on morphological characters and geographical distribution may be the least disruptive approach, and it is reasonable to keep Satyrium in Orchidinae.
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Affiliation(s)
- Wei-Tao Jin
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 10093 China
| | - André Schuiteman
- Identification and Naming Department, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB UK
| | - Mark W. Chase
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3DS UK
- School of Plant Biology, University of Western Australia, Crawley, Perth, 6009 Australia
| | - Jian-Wu Li
- Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun Township, Mengla County, Yunnan 666303 China
| | - Shih-Wen Chung
- Botanical Garden Division, Taiwan Forestry Research Institute, 53 Nanhai Road, Taipei, Taiwan 10066 China
| | - Tian-Chuan Hsu
- Department of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan 30013 China
| | - Xiao-Hua Jin
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 10093 China
- Southeast Asia Biodiversity Research Institute, Chinese Academy of Science (CAS-SEABRI), Yezin, Nay Pyi Taw, Myanmar
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Abstract
Orchidaceae, one of the largest families of flowering plants, present particular challenges for conservation, due in great part to their often complex interactions with mycorrhizal fungi, pollinators and host trees. In this Highlight, we present seven papers focusing on orchids and their interactions and other factors relating to their conservation.
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Affiliation(s)
- Michael F Fay
- Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3DS, UK,
| | - Thierry Pailler
- Peuplements Végétaux et Bioagresseurs en Milieu Tropical, CIRAD-Université de La Réunion, 15 Avenue René Cassin BP 7151, 97715 Saint-Denis, La Réunion, France and
| | - Kingsley W Dixon
- Department of Environment and Agriculture, Curtin University, Kent Street, Bentley, Perth, Western Australia, 6102, Australia
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Breitkopf H, Onstein RE, Cafasso D, Schlüter PM, Cozzolino S. Multiple shifts to different pollinators fuelled rapid diversification in sexually deceptive Ophrys orchids. THE NEW PHYTOLOGIST 2015; 207:377-389. [PMID: 25521237 DOI: 10.1111/nph.13219] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 10/31/2014] [Indexed: 05/03/2023]
Abstract
Episodes of rapid speciation provide unique insights into evolutionary processes underlying species radiations and patterns of biodiversity. Here we investigated the radiation of sexually deceptive bee orchids (Ophrys). Based on a time-calibrated phylogeny and by means of ancestral character reconstruction and divergence time estimation, we estimated the tempo and mode of this radiation within a state-dependent evolutionary framework. It appears that, in the Pleistocene, the evolution of Ophrys was marked by episodes of rapid diversification coinciding with shifts to different pollinator types: from wasps to Eucera bees to Andrena and other bees. An abrupt increase in net diversification rate was detected in three clades. Among these, two phylogenetically distant lineages switched from Eucera to Andrena and other bees in a parallel fashion and at about the same time in their evolutionary history. Lack of early radiation associated with the evolution of the key innovation of sexual deception suggests that Ophrys diversification was mainly driven by subsequent ecological opportunities provided by the exploitation of novel pollinator groups, encompassing many bee species slightly differing in their sex pheromone communication systems, and by spatiotemporal fluctuations in the pollinator mosaic.
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Affiliation(s)
- Hendrik Breitkopf
- Department of Biology, University of Naples Federico II, Naples, Italy
- Institute of Biochemistry and Biology, Biodiversity Research/Systematic Botany, University of Potsdam, Potsdam, Germany
| | - Renske E Onstein
- Institute of Systematic Botany, University of Zurich, Zurich, Switzerland
| | - Donata Cafasso
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Philipp M Schlüter
- Institute of Systematic Botany, University of Zurich, Zurich, Switzerland
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Sramkó G, Attila MV, Hawkins JA, Bateman RM. Molecular phylogeny and evolutionary history of the Eurasiatic orchid genus Himantoglossum s.l. (Orchidaceae). ANNALS OF BOTANY 2014; 114:1609-26. [PMID: 25294871 PMCID: PMC4649687 DOI: 10.1093/aob/mcu179] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
BACKGROUND AND AIMS Lizard orchids of the genus Himantoglossum include many of Eurasia's most spectacular orchids, producing substantial spikes of showy flowers. However, until recently the genus had received only limited, and entirely traditional, systematic study. The aim of the current work was to provide a more robust molecular phylogeny in order to better understand the evolutionary relationships among species of particular conservation concern. METHODS All putative species of Himantoglossum s.l. were sampled across its geographical range. A large subsample of the 153 populations studied contributed to an initial survey of nuclear ribosomal internal transcribed spacer (nrITS) ribotypes. Smaller subsets were then sequenced for four plastid regions and the first intron of the low-copy-number nuclear gene LEAFY. Rooted using Steveniella as outgroup, phylogenetic trees were generated using parsimony and Bayesian methods from each of the three datasets, supplemented with a ribotype network. KEY RESULTS The resulting trees collectively determined the order of branching of the early divergent taxa as Himantoglossum comperianum > H. robertianum group > H. formosum, events that also involved significant morphological divergence. Relaxed molecular clock dating suggested that these divergences preceded the Pleistocene glaciations (the origin of the H. robertianum group may have coincided with the Messinian salinity crisis) and occurred in Asia Minor and/or the Caucasus. Among more controversial taxa of the H. hircinum-jankae clade, which are only subtly morphologically divergent, topological resolution was poorer and topological incongruence between datasets was consequently greater. CONCLUSIONS Plastid sequence divergence is broadly consistent with prior, morphologically circumscribed taxa and indicates a division between H. hircinum-adriaticum to the west of the Carpathians and H. jankae-caprinum (plus local endemics) to the east, a distinction also suggested by nrITS ribotypes. LEAFY phylogenies are less congruent with prior taxonomic arrangements and include one likely example of paralogy. Himantoglossum metlesicsianum fully merits its IUCN Endangered status. Potentially significant genetic variation was detected within Steveniella satyrioides, H. robertianum and H. hircinum. However, confident circumscription of the more derived species of Himantoglossum s.s., including local endemics of hybrid origin, must await future morphometric and population-genetic analyses.
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Affiliation(s)
- Gábor Sramkó
- MTA-ELTE-MTM Ecology Research Group, Pázmány P. sétány 1/C, Budapest, 1117, Hungary Department of Botany, University of Debrecen, Egyetem ter 1., Debrecen, 4032, Hungary
| | - Molnár V Attila
- Department of Botany, University of Debrecen, Egyetem ter 1., Debrecen, 4032, Hungary
| | - Julie A Hawkins
- School of Biological Sciences, University of Reading, Reading RG6 6AS, UK
| | - Richard M Bateman
- Jodrell Laboratory, Royal Botanical Gardens Kew, Richmond, Surrey TW9 3DS, UK
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An evaluation of taxonomic concepts of the widespread plant genus Aglaia and its allies across Wallace's Line (tribe Aglaieae, Meliaceae). Mol Phylogenet Evol 2014; 73:65-76. [PMID: 24495856 DOI: 10.1016/j.ympev.2014.01.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 11/28/2013] [Accepted: 01/14/2014] [Indexed: 11/22/2022]
Abstract
Similar to other species-rich taxa in the Indo-Australian Archipelago, taxonomy of the genus Aglaia (mahogany family, Meliaceae) remains problematic. This study aims to evaluate taxonomic concepts within Aglaia based on the largest dataset to-date. We analyzed sequences of 237 accessions of Aglaia and representatives of all other genera of the tribe Aglaieae, including nuclear ribosomal ITS, the trnL-trnF intron and intergenic spacer, the atpF intron and the petD region comprising the petB-petD spacer, the petD-5' exon and the petD intron (all but the first from the plastid genome). Our analyses were set both in maximum likelihood and Bayesian frameworks, which (1) supported paraphyly of Aglaia and Aphanamixis; (2) demonstrated polyphyly of previously described sections for Aglaia; and (3) suggested delimitation problems with 57% of the morphologically "variable species" and all "complex species". In general, there were more genetic entities than species described, which shows that the taxonomy of this group is more complex than has sometimes been previously assumed. For some species, morphological variation suggests the existence of more variants, subspecies or species within various taxa. Furthermore, our study detected additional phylogenetic entities that were geographically distinct, occurring on either side of Wallace's Line but not on both sides. The delineation of these inter-specific taxa needs further investigation by taking into account the morphological variation within and between populations across the entire distribution.
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Ahrens CW, James EA. Characterization of 13 microsatellite markers for Diuris basaltica (Orchidaceae) and related species. APPLICATIONS IN PLANT SCIENCES 2014; 2:apps1300069. [PMID: 25202591 PMCID: PMC4104714 DOI: 10.3732/apps.1300069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 10/03/2013] [Indexed: 05/23/2023]
Abstract
PREMISE OF THE STUDY Diuris basaltica (Orchidaceae) is an endangered forb on the Victorian grasslands and has many close relatives. Microsatellite markers have been developed to facilitate assessment of population structure within D. basaltica and among related taxa within the species complex. • METHODS AND RESULTS Twenty-five microsatellite markers (13 polymorphic and 12 monomorphic) were developed from D. basaltica using 454 pyrosequencing, and all primer pairs were amplified in D. gregaria and D. chryseopsis. For the set of polymorphic markers, the number of alleles per locus ranged from one to 10, two to nine, and two to 18 for D. basaltica, D. gregaria, and D. chryseopsis, respectively. The expected and observed heterozygosities ranged from 0.18 to 0.95 and 0.14 to 0.86, respectively. • CONCLUSIONS The microsatellite markers developed in this study can be used to analyze the population genetic structure of D. basaltica and other Diuris species.
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Affiliation(s)
- Collin W. Ahrens
- Royal Botanic Gardens Melbourne, National Herbarium of Victoria, Private Bag 2000, Birdwood Ave., South Yarra, Victoria 3141, Australia
| | - Elizabeth A. James
- Royal Botanic Gardens Melbourne, National Herbarium of Victoria, Private Bag 2000, Birdwood Ave., South Yarra, Victoria 3141, Australia
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Bateman RM, James KE, Rudall PJ. Contrast in levels of morphological versus molecular divergence between closely related Eurasian species ofPlatanthera(Orchidaceae) suggests recent evolution with a strong allometric component. ACTA ACUST UNITED AC 2013. [DOI: 10.1179/2042349712y.0000000013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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11
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Breitkopf H, Schlüter PM, Xu S, Schiestl FP, Cozzolino S, Scopece G. Pollinator shifts between Ophrys sphegodes
populations: might adaptation to different pollinators drive population divergence? J Evol Biol 2013; 26:2197-208. [DOI: 10.1111/jeb.12216] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 06/07/2013] [Accepted: 06/14/2013] [Indexed: 11/28/2022]
Affiliation(s)
- H. Breitkopf
- Department of Biology; University of Naples Federico II; Naples Italy
- Institute of Biochemistry and Biology, Biodiversity Research/Systematic Botany; University of Potsdam; Potsdam Germany
| | - P. M. Schlüter
- Institute of Systematic Botany; University of Zürich; Zurich Switzerland
| | - S. Xu
- Institute of Systematic Botany; University of Zürich; Zurich Switzerland
- Molecular Ecology Department; Max Planck Institute for Chemical Ecology; Jena Germany
| | - F. P. Schiestl
- Institute of Systematic Botany; University of Zürich; Zurich Switzerland
| | - S. Cozzolino
- Department of Biology; University of Naples Federico II; Naples Italy
| | - G. Scopece
- Department of Biology; University of Naples Federico II; Naples Italy
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Triponez Y, Arrigo N, Pellissier L, Schatz B, Alvarez N. Morphological, ecological and genetic aspects associated with endemism in the Fly Orchid group. Mol Ecol 2013; 22:1431-46. [DOI: 10.1111/mec.12169] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2011] [Revised: 10/11/2012] [Accepted: 10/19/2012] [Indexed: 11/26/2022]
Affiliation(s)
- Yann Triponez
- Department of Evolution, Ecology and Genetics; Research School of Biology; The Australian National University; Canberra ACT 0200 Australia
- Laboratory of Evolutionary Entomology; University of Neuchâtel; Emile-Argand 11 CH-2000 Neuchâtel Switzerland
| | - Nils Arrigo
- Department of Ecology and Evolutionary Biology; University of Arizona; Tucson AZ 85721 USA
- Department of Ecology and Evolution; Biophore Dorigny; University of Lausanne; CH-1015 Lausanne Switzerland
| | - Loïc Pellissier
- Department of Ecology and Evolution; Biophore Dorigny; University of Lausanne; CH-1015 Lausanne Switzerland
| | - Bertrand Schatz
- Centre d'Ecologie Fonctionnelle et Evolutive; CNRS Montpellier; UMR 5175; 1919 Route de Mende F-34293 Montpellier Cedex 5 France
| | - Nadir Alvarez
- Department of Ecology and Evolution; Biophore Dorigny; University of Lausanne; CH-1015 Lausanne Switzerland
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13
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AFLP analysis of genetic variation in wild populations of five Rhododendron species in Qinling Mountain in China. BIOCHEM SYST ECOL 2012. [DOI: 10.1016/j.bse.2012.07.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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14
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Pollinator-Driven Speciation in Sexually Deceptive Orchids. INTERNATIONAL JOURNAL OF ECOLOGY 2012. [DOI: 10.1155/2012/285081] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Pollinator-mediated selection has been suggested to play a major role for the origin and maintenance of the species diversity in orchids. Sexually deceptive orchids are one of the prime examples for rapid, pollinator-mediated plant radiations, with many species showing little genetic differentiation, lack of postzygotic barriers, but strong prezygotic reproductive isolation. These orchids mimic mating signals of female insects and employ male insects as pollinators. This kind of sexual mimicry leads to highly specialised pollination and provides a good system for investigating the process of pollinator-driven speciation. Here, we summarise the knowledge of key processes of speciation in this group of orchids and conduct a meta-analysis on traits that contribute to species differentiation, and thus potentially to speciation. Our study suggests that pollinator shift through changes in floral scent is predominant among closely related species in sexually deceptive orchids. Such shifts can provide a mechanism for pollinator-driven speciation in plants, if the resulting floral isolation is strong. Furthermore, changes in floral scent in these orchids are likely controlled by few genes. Together these factors suggest speciation in sexually deceptive orchids may happen rapidly and even in sympatry, which may explain the remarkable species diversity observed in this plant group.
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An unexpected new record of the Mediterranean orchid, Ophrys bertolonii (Orchidaceae) in Central Europe. Biologia (Bratisl) 2011. [DOI: 10.2478/s11756-011-0086-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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16
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STÅHLBERG DAVID, HEDRÉN MIKAEL. Evolutionary history of the Dactylorhiza maculata polyploid complex (Orchidaceae). Biol J Linn Soc Lond 2010. [DOI: 10.1111/j.1095-8312.2010.01505.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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17
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Fay MF, Chase MW. Orchid biology: from Linnaeus via Darwin to the 21st century. Preface. ANNALS OF BOTANY 2009; 104:359-64. [PMID: 19654223 PMCID: PMC2720656 DOI: 10.1093/aob/mcp190] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Orchidaceae are the largest family of flowering plants, with at least 24,000 species, and perhaps better than any other family of flowering plants, orchids represent the extreme specializations that are possible. As a result, they have long fascinated luminaries of the botanical world including Linnaeus and Darwin, but the size of the family has historically been an impediment to their study. Specifically, the lack of detailed information about relationships within the family made it difficult to formulate explicit evolutionary hypotheses for such a large group, but the advent of molecular systematics has revolutionized our understanding of the orchids. Their complex life histories make orchids particularly vulnerable to environmental change, and as result many are now threatened with extinction. In this Special Issue we present a series of 20 papers on orchid biology ranging from phylogenetics, floral evolutionary development, taxonomy, mycorrhizal associations, pollination biology, population genetics and conservation.
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Affiliation(s)
- Michael F Fay
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK.
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