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Basist G, Dyer AG, Garcia JE, Raleigh RE, Lawrie AC. Why Variation in Flower Color May Help Reproductive Success in the Endangered Australian Orchid Caladenia fulva. FRONTIERS IN PLANT SCIENCE 2021; 12:599874. [PMID: 33633758 PMCID: PMC7899986 DOI: 10.3389/fpls.2021.599874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 01/15/2021] [Indexed: 05/27/2023]
Abstract
Caladenia fulva G.W. Carr (Tawny Spider-orchid) is a terrestrial Australian endangered orchid confined to contiguous reserves in open woodland in Victoria, Australia. Natural recruitment is poor and no confirmed pollinator has been observed in the last 30 years. Polymorphic variation in flower color complicates plans for artificial pollination, seed collection and ex situ propagation for augmentation or re-introduction. DNA sequencing showed that there was no distinction among color variants in the nuclear ribosomal internal transcribed spacer (ITS) region and the chloroplast trnT-trnF and matK regions. Also, authentic specimens of both C. fulva and Caladenia reticulata from the reserves clustered along with these variants, suggesting free interbreeding. Artificial cross-pollination in situ and assessment of seed viability further suggested that no fertility barriers existed among color variants. Natural fruit set was 15% of the population and was proportional to numbers of the different flower colors but varied with orchid patch within the population. Color modeling on spectral data suggested that a hymenopteran pollinator could discriminate visually among color variants. The similarity in fruiting success, however, suggests that flower color polymorphism may avoid pollinator habituation to specific non-rewarding flower colors. The retention of large brightly colored flowers suggests that C. fulva has maintained attractiveness to foraging insects rather than evolving to match a scarce unreliable hymenopteran sexual pollinator. These results suggest that C. fulva should be recognized as encompassing plants with these multiple flower colors, and artificial pollination should use all variants to conserve the biodiversity of the extant population.
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Affiliation(s)
- Georgia Basist
- School of Science, RMIT University, Bundoora, VIC, Australia
| | - Adrian G. Dyer
- Bio-inspired Digital Sensing Lab, School of Media and Communication, RMIT University, Melbourne, VIC, Australia
- Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Jair E. Garcia
- Bio-inspired Digital Sensing Lab, School of Media and Communication, RMIT University, Melbourne, VIC, Australia
| | - Ruth E. Raleigh
- School of Science, RMIT University, Bundoora, VIC, Australia
- Royal Botanic Gardens Melbourne, South Yarra, VIC, Australia
| | - Ann C. Lawrie
- School of Science, RMIT University, Bundoora, VIC, Australia
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Conservation in the face of hybridisation: genome-wide study to evaluate taxonomic delimitation and conservation status of a threatened orchid species. CONSERV GENET 2021. [DOI: 10.1007/s10592-020-01325-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Wong DCJ, Amarasinghe R, Falara V, Pichersky E, Peakall R. Duplication and selection in β-ketoacyl-ACP synthase gene lineages in the sexually deceptive Chiloglottis (Orchidaceace). ANNALS OF BOTANY 2019; 123:1053-1066. [PMID: 30789664 PMCID: PMC6589519 DOI: 10.1093/aob/mcz013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Accepted: 02/05/2019] [Indexed: 05/17/2023]
Abstract
BACKGROUND AND AIMS The processes of gene duplication, followed by divergence and selection, probably underpin the evolution of floral volatiles crucial to plant-insect interactions. The Australian sexually deceptive Chiloglottis orchids use a class of 2,5-dialkylcyclohexan-1,3-dione volatiles or 'chiloglottones' to attract specific male wasp pollinators. Here, we explore the expression and evolution of fatty acid pathway genes implicated in chiloglottone biosynthesis. METHODS Both Chiloglottis seminuda and C. trapeziformis produce chiloglottone 1, but only the phylogenetically distinct C. seminuda produces this volatile from both the labellum callus and glandular sepal tips. Transcriptome sequencing and tissue-specific contrasts of the active and non-active floral tissues was performed. The effects of the fatty acid synthase inhibitor cerulenin on chiloglottone production were tested. Patterns of selection and gene evolution were investigated for fatty acid pathway genes. KEY RESULTS Tissue-specific differential expression of fatty acid pathway transcripts was evident between active and non-active floral tissues. Cerulenin significantly inhibits chiloglottone 1 production in the active tissues of C. seminuda. Phylogenetic analysis of plant β-ketoacyl synthase I (KASI), a protein involved in fatty acid biosynthesis, revealed two distinct clades, one of which is unique to the Orchidaceae (KASI-2B). Selection analysis indicated a strong signal of positive selection at the split of KASI-2B followed by relaxed purifying selection in the Chiloglottis clade. CONCLUSIONS By capitalizing on a phylogenetically distinct Chiloglottis from earlier studies, we show that the transcriptional and biochemical dynamics linked to chiloglottone biosynthesis in active tissues are conserved across Chiloglottis. A combination of tissue-specific expression and relaxed purifying selection operating at specific fatty acid pathway genes may hold the key to the evolution of chiloglottones.
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Affiliation(s)
- Darren C J Wong
- Ecology and Evolution, Research School of Biology, The Australian National University, Acton, Australia
- For correspondence. E-mail ,
| | - Ranamalie Amarasinghe
- Ecology and Evolution, Research School of Biology, The Australian National University, Acton, Australia
| | - Vasiliki Falara
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Eran Pichersky
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Rod Peakall
- Ecology and Evolution, Research School of Biology, The Australian National University, Acton, Australia
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Lamont BB, He T, Yan Z. Evolutionary history of fire‐stimulated resprouting, flowering, seed release and germination. Biol Rev Camb Philos Soc 2018; 94:903-928. [DOI: 10.1111/brv.12483] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 10/23/2018] [Accepted: 11/01/2018] [Indexed: 12/18/2022]
Affiliation(s)
- Byron B. Lamont
- School of Molecular and Life Sciences Curtin University PO Box U1987, Perth, WA 6845 Australia
| | - Tianhua He
- School of Molecular and Life Sciences Curtin University PO Box U1987, Perth, WA 6845 Australia
| | - Zhaogui Yan
- College of Horticulture and Forestry Sciences Huazhong Agricultural University Wuhan 430070 China
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Gaskett AC, Gallagher RV. Orchid diversity: Spatial and climatic patterns from herbarium records. Ecol Evol 2018; 8:11235-11245. [PMID: 30519440 PMCID: PMC6262934 DOI: 10.1002/ece3.4598] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 09/10/2018] [Accepted: 09/16/2018] [Indexed: 01/31/2023] Open
Abstract
AIM We test for spatial and climatic patterns of diversification in the Orchidaceae, an angiosperm family characterized by high levels of species diversity and rarity. Globally, does orchid diversity correlate with land area? In Australia, does diversity correlate with herbarium collecting effort, range size, or climate niche breadth? Where are Australia's orchids distributed spatially, in protected areas, and in climate space? LOCATION Global, then Australia. METHODS We compared orchid diversity with land area for continents and recognized orchid diversity hotspots. Then, we used cleaned herbarium records to compare collecting effort (for Australian Orchidaceae vs. all other plant families, and also among orchid genera). Spatial and climate distributions were mapped to determine orchids' coverage in the protected area network, range sizes, and niche breadths. RESULTS Globally, orchid diversity does not correlate with land area (depauperate regions are the subantarctic: 10 species, and northern North America: 394 species). Australian herbarium records and collecting effort generally reflect orchid species diversity (1,583 spp.), range sizes, and niche breadths. Orchids are restricted to 13% of Australia's landmass with 211 species absent from any protected areas. Species richness is the greatest in three biomes with high general biodiversity: Temperate (especially southwest and southeast Australia), Tropical, and Subtropical (coastal northern Queensland). Absence from the Desert is consistent with our realized climate niche-orchids avoid high temperature/low rainfall environments. Orchids have narrower range sizes than nonorchid species. Highly diverse orchid genera have narrower rainfall breadths than less diverse genera. MAIN CONCLUSIONS Herbarium data are adequate for testing hypotheses about Australian orchids. Distribution is likely driven by environmental factors. In contrast, diversification did not correlate with increases in range size, rainfall, or temperature breadths, suggesting speciation does not occur via invasion and local adaptation to new habitats. Instead, diversification may rely on access to extensive obligate symbioses with mycorrhizae and/or pollinators.
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Affiliation(s)
- Anne C. Gaskett
- School of Biological SciencesThe University of AucklandAucklandNew Zealand
| | - Rachael V. Gallagher
- Department of Biological SciencesMacquarie UniversitySydneyNew South WalesAustralia
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Simpson L, Clements MA, Crayn DM, Nargar K. Evolution in Australia’s mesic biome under past and future climates: Insights from a phylogenetic study of the Australian Rock Orchids (Dendrobium speciosum complex, Orchidaceae). Mol Phylogenet Evol 2018; 118:32-46. [DOI: 10.1016/j.ympev.2017.09.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 07/20/2017] [Accepted: 09/05/2017] [Indexed: 10/18/2022]
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Yang R, Cai X, Li X, Christie P, Zhang J, Gai J. Temperature-mediated local adaptation alters the symbiotic function in arbuscular mycorrhiza. Environ Microbiol 2017; 19:2616-2628. [PMID: 28345305 DOI: 10.1111/1462-2920.13737] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 03/19/2017] [Accepted: 03/20/2017] [Indexed: 11/29/2022]
Abstract
Variation in the symbiotic function of arbuscular mycorrhizal fungi (AM fungi) has been demonstrated among distinct biotic and abiotic interactions. However, there is little knowledge on how local temperature conditions influence the functional divergence of AM symbionts in alpine ecosystems. Here, we conduct a reciprocal inoculation experiment to explore the three-way interactions among plants, AM fungal inoculum and temperature at sites of contrasting elevation. Evidence of local adaptation of plant growth was found only under low temperature conditions, with no consistent local versus foreign effect found in AM fungal performance. The origin of either the plant or the inoculum relative to the temperature was important in explaining symbiotic function. Specifically, when inoculum and temperature were sympatric but allopatric to the plant, poor adaptation by the plant to the novel environment was clearly found under both temperature conditions. Further analysis found that the symbiotic function was inversely related to fungal diversity under high temperature conditions. These results suggest that local adaptation represents a powerful factor in the establishment of novel combinations of plant, inoculum and temperature, and confirms the importance of taking into account both biotic and abiotic interactions in the prediction of the response of symbionts to global environmental change.
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Affiliation(s)
- Rong Yang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention, Control and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China.,College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Xiaobu Cai
- Tibet Agricultural and Animal Husbandry College, Tibet University, Linzhi, 860000, China
| | - Xiaolin Li
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Peter Christie
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Junling Zhang
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Jingping Gai
- Beijing Key Laboratory of Farmland Soil Pollution Prevention, Control and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China.,College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
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Mehra S, Morrison PD, Coates F, Lawrie AC. Differences in carbon source utilisation by orchid mycorrhizal fungi from common and endangered species of Caladenia (Orchidaceae). MYCORRHIZA 2017; 27:95-108. [PMID: 27639577 DOI: 10.1007/s00572-016-0732-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 08/22/2016] [Indexed: 06/06/2023]
Abstract
Terrestrial orchids depend on orchid mycorrhizal fungi (OMF) as symbionts for their survival, growth and nutrition. The ability of OMF from endangered orchid species to compete for available resources with OMF from common species may affect the distribution, abundance and therefore conservation status of their orchid hosts. Eight symbiotically effective OMF from endangered and more common Caladenia species were tested for their ability to utilise complex insoluble and simple soluble carbon sources produced during litter degradation by growth with different carbon sources in liquid medium to measure the degree of OMF variation with host conservation status or taxonomy. On simple carbon sources, fungal growth was assessed by biomass. On insoluble substrates, ergosterol content was assessed using ultra-performance liquid chromatography (UPLC). The OMF grew on all natural materials and complex carbon sources, but produced the greatest biomass on xylan and starch and the least on bark and chitin. On simple carbon sources, the greatest OMF biomass was measured on most hexoses and disaccharides and the least on galactose and arabinose. Only some OMF used sucrose, the most common sugar in green plants, with possible implications for symbiosis. OMF from common orchids produced more ergosterol and biomass than those from endangered orchids in the Dilatata and Reticulata groups but not in the Patersonii and Finger orchids. This suggests that differences in carbon source utilisation may contribute to differences in the distribution of some orchids, if these differences are retained on site.
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Affiliation(s)
- S Mehra
- School of Science, RMIT University (Bundoora West Campus), PO Box 71, Bundoora, Victoria, 3083, Australia
| | - P D Morrison
- Australian Centre for Research on Separation Science, School of Science, RMIT University (City Campus), GPO Box 2476V, Melbourne, Victoria, 3001, Australia
| | - F Coates
- Department of Environment and Primary Industries, Melbourne, Victoria, 3002, Australia
- Woods to Water Environmental Consulting, Williamstown, VIC, 3016, Australia
| | - A C Lawrie
- School of Science, RMIT University (Bundoora West Campus), PO Box 71, Bundoora, Victoria, 3083, Australia.
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Clements MA, Howard CG, Miller JT. Caladenia revisited: Results of molecular phylogenetic analyses of Caladeniinae plastid and nuclear loci. AMERICAN JOURNAL OF BOTANY 2015; 102:581-597. [PMID: 25878091 DOI: 10.3732/ajb.1500021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 03/13/2015] [Indexed: 06/04/2023]
Abstract
PREMISE OF THE STUDY The classification of the primarily Australasian group of orchids Caladenia and allied genera (Caladeniinae: Diurideae) containing 71 federally listed threatened species has proven controversial. Analyzing these species using genetic material will provide a sound basis for their classification and the capacity to ensure accurate conservation measures can be implemented. METHODS We present a multigene analysis based on nuclear ribosomal ITS and five plastid regions from 54 species representing all major taxonomic groups within Caladeniinae. KEY RESULTS In our combined analysis, apart from Leptoceras and Praecoxanthus, all Caladenia ingroup taxa form a strongly supported clade that is also supported by morphological synapomorphies (parallel leaf venation; leaf solitary, lanceolate, covered with glandular or eglandular trichomes). Characters and character states historically used to delimit taxa were revealed to be homoplasious and therefore do not support recognition of Arachnorchis, Cyanicula, Drakonorchis, Ericksonella, Jonesiopsis, Petalochilus, Pheladenia, and Stegostyla as previously proposed. Glossodia and Elythranthera are shown to be a specialist group embedded within Caladenia. CONCLUSIONS Based on our results, none of the current systems of classification of the subtribe is satisfactory. Instead our results point to Lindley's 1840 interpretation of Caladenia, but including Glossodia and Elythranthera, as being the most accurate reflection of the group. Accordingly, a renewed reclassification of Caladeniinae is proposed as well as several new combinations.
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Affiliation(s)
- Mark A Clements
- Centre for Australian National Biodiversity Research, GPO Box 1600 Canberra ACT 2601, Australia
| | - Christopher G Howard
- Centre for Australian National Biodiversity Research, GPO Box 1600 Canberra ACT 2601, Australia
| | - Joseph T Miller
- Centre for Australian National Biodiversity Research, GPO Box 1600 Canberra ACT 2601, Australia
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Herberstein ME, Baldwin HJ, Gaskett AC. Deception down under: is Australia a hot spot for deception? Behav Ecol 2013. [DOI: 10.1093/beheco/art105] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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A review of the use of genetic markers in orchid systematics with emphasis on allozymes. BIOCHEM SYST ECOL 2012. [DOI: 10.1016/j.bse.2011.12.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Abstract
The extraordinary taxonomic and morphological diversity of orchids is accompanied by a remarkable range of pollinators and pollination systems. Sexually deceptive orchids are adapted to attract specific male insects that are fooled into attempting to mate with orchid flowers and inadvertently acting as pollinators. This review summarises current knowledge, explores new hypotheses in the literature, and introduces some new approaches to understanding sexual deception from the perspective of the duped pollinator. Four main topics are addressed: (1) global patterns in sexual deception, (2) pollinator identities, mating systems and behaviours, (3) pollinator perception of orchid deceptive signals, and (4) the evolutionary implications of pollinator responses to orchid deception, including potential costs imposed on pollinators by orchids. A global list of known and putative sexually deceptive orchids and their pollinators is provided and methods for incorporating pollinator perspectives into sexual deception research are provided and reviewed. At present, almost all known sexually deceptive orchid taxa are from Australia or Europe. A few sexually deceptive species and genera are reported for New Zealand and South Africa. In Central and Southern America, Asia, and the Pacific many more species are likely to be identified in the future. Despite the great diversity of sexually deceptive orchid genera in Australia, pollination rates reported in the literature are similar between Australian and European species. The typical pollinator of a sexually deceptive orchid is a male insect of a species that is polygynous, monandrous, haplodiploid, and solitary rather than social. Insect behaviours involved in the pollination of sexually deceptive orchids include pre-copulatory gripping of flowers, brief entrapment, mating, and very rarely, ejaculation. Pollinator behaviour varies within and among pollinator species. Deception involving orchid mimicry of insect scent signals is becoming well understood for some species, but visual and tactile signals such as colour, shape, and texture remain neglected. Experimental manipulations that test for function, multi-signal interactions, and pollinator perception of these signals are required. Furthermore, other forms of deception such as exploitation of pollinator sensory biases or mating preferences merit more comprehensive investigation. Application of molecular techniques adapted from model plants and animals is likely to deliver new insights into orchid signalling, and pollinator perception and behaviour. There is little current evidence that sexual deception drives any species-level selection on pollinators. Pollinators do learn to avoid deceptive orchids and their locations, but this is not necessarily a response specific to orchids. Even in systems where evidence suggests that orchids do interfere with pollinator mating opportunities, considerable further research is required to determine whether this is sufficient to impose selection on pollinators or generate antagonistic coevolution or an arms race between orchids and their pollinators. Botanists, taxonomists and chemical ecologists have made remarkable progress in the study of deceptive orchid pollination. Further complementary investigations from entomology and behavioural ecology perspectives should prove fascinating and engender a more complete understanding of the evolution and maintenance of such enigmatic plant-animal interactions.
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Affiliation(s)
- A C Gaskett
- Department of Biological Sciences, Macquarie University, NSW, Australia.
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SWARTS NIGELD, SINCLAIR ELIZABETHA, FRANCIS ANTHONY, DIXON KINGSLEYW. Ecological specialization in mycorrhizal symbiosis leads to rarity in an endangered orchid. Mol Ecol 2010; 19:3226-42. [DOI: 10.1111/j.1365-294x.2010.04736.x] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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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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