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Phillips RD, Bohman B, Peakall R, Reiter N. Sexual attraction with pollination during feeding behaviour: implications for transitions between specialized strategies. Ann Bot 2024; 133:273-286. [PMID: 37963103 PMCID: PMC11005785 DOI: 10.1093/aob/mcad178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 11/13/2023] [Indexed: 11/16/2023]
Abstract
BACKGROUND AND AIMS Understanding the origin of pollination by sexual deception has proven challenging, as sexually deceptive flowers are often highly modified, making it hard to resolve how any intermediate forms between sexual deception and an ancestral strategy might have functioned. Here, we report the discovery in Caladenia (Orchidaceae) of sexual attraction with pollination during feeding behaviour, which may offer important clues for understanding shifts in pollination strategy. METHODS For Caladenia robinsonii, we observed the behaviour of its male wasp pollinator, Phymatothynnus aff. nitidus (Thynnidae), determined the site of release of the sexual attractant, and experimentally evaluated if the position of the attractant influences rates of attempted copulation and feeding behaviour. We applied GC-MS to test for surface sugar on the labellum. To establish if this pollination strategy is widespread in Caladenia, we conducted similar observations and experiments for four other Caladenia species. KEY RESULTS In C. robinsonii, long-range sexual attraction of the pollinator is via semiochemicals emitted from the glandular sepal tips. Of the wasps landing on the flower, 57 % attempted copulation with the sepal tips, while 27 % attempted to feed from the base of the labellum, the behaviour associated with pollen transfer. A similar proportion of wasps exhibited feeding behaviour when the site of odour release was manipulated. A comparable pollination strategy occurs in another phylogenetically distinct clade of Caladenia. CONCLUSIONS We document a previously overlooked type of sexual deception for orchids involving long-distance sexual attraction, but with pollination occurring during feeding behaviour at the labellum. We show this type of sexual deception operates in other Caladenia species and predict that it is widespread across the genus. Our findings may offer clues about how an intermediate transitional strategy from a food-rewarding or food-deceptive ancestor operated during the evolution of sexual deception.
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Affiliation(s)
- Ryan D Phillips
- Department of Environment and Genetics and the Research Centre for Future Landscapes, La Trobe University, Melbourne, Victoria 3086, Australia
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
- Royal Botanic Gardens Victoria, Science Division, Corner of Ballarto Road and Botanic Drive, Cranbourne, VIC 3977, Australia
- Kings Park and Botanic Garden, The Botanic Garden and Parks Authority, West Perth, WA 6005, Australia
| | - Björn Bohman
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
- Department of Plant Protection Biology, the Swedish University of Agricultural Sciences, Lomma 23422, Sweden
- School of Molecular Sciences, The University of Western Australia Crawley, WA 6009Australia
| | - Rod Peakall
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
| | - Noushka Reiter
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
- Royal Botanic Gardens Victoria, Science Division, Corner of Ballarto Road and Botanic Drive, Cranbourne, VIC 3977, Australia
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Claßen-Bockhoff R, Celep F, Ajani Y, Frenken L, Reuther K, Doğan M. Dark-centred umbels in Apiaceae: diversity, development and evolution. AoB Plants 2023; 15:plad065. [PMID: 37908286 PMCID: PMC10614004 DOI: 10.1093/aobpla/plad065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Accepted: 09/08/2023] [Indexed: 11/02/2023]
Abstract
The wild carrot (Daucus carota) is famous for its dark flowers in the umbel centre. Several studies have been conducted to figure out their functional significance, but the evolution of the dark centre remains an enigma. In the present paper, we consider all known apioid species with dark-centred umbels to get a deeper understanding of their biology and evolution. Based on herbaria studies, literature and field work, we reconstructed the distribution area of 10 species (7 genera, 6 clades) of Apiaceae-Apioideae. To recognize homology of the dark structures, developmental studies were conducted in Artedia squamata and Echiophora trichophylla Field studies included architecture, flower morph distribution (andromonoecy) and flowering sequence within the plants, abundancy and behaviour of umbel visitors and preliminary manipulation experiments (removal/adding of dark structures). The dark structures are not homologous to each other. In the Daucus alliance, central flowers or umbellets are conspicuous, whereas in other species dark brush-like (A. squamata) or club-shaped structures (Dicyclophora persica, Echinophora trichophylla, Tordylium aegyptiacum, T. cappadocicum) develop from a naked receptacle. Species are andromonoecious, have a modular architecture and flower in multicyclic protandrous sequence. Among the many umbel visitors, beetles were the most abundant group. Only visitors found on umbels in both flowering phases were recognized as possible pollinators. Manipulation experiments indicated that the dark structures influence the behaviour of some, but not all umbel visitors. In Echinophora trichophylla, a massive gall infection was observed. It is evident that the dark structures evolved several times in parallel. The brush- and club-shaped structures are interpreted as the results of mutations affecting umbel development. Dark umbel centres are most likely stabilized by selection due to their general adaptive function. Their appearance in an area known as a hotspot of beetle pollination gives rise to the assumption that they may act as beetle marks.
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Affiliation(s)
- Regine Claßen-Bockhoff
- Institute of Organismic and Molecular Evolution (IOME), Department of Biology, Johannes Gutenberg-University, Saarstraße 21, 55099 Mainz, Germany
| | - Ferhat Celep
- Faculty of Science and Letters, Department of Biology, Kırıkkale University, Kırıkkale, Yahşihan, P.O. 71450, Turkey
| | - Yousef Ajani
- Institute of Organismic and Molecular Evolution (IOME), Department of Biology, Johannes Gutenberg-University, Saarstraße 21, 55099 Mainz, Germany
- Department of Botany, Research Institute of Forests and Rangelands, P.O. Box 13185-116, Tehran, Iran
| | - Lisa Frenken
- Institute of Organismic and Molecular Evolution (IOME), Department of Biology, Johannes Gutenberg-University, Saarstraße 21, 55099 Mainz, Germany
| | - Kerstin Reuther
- Institute of Organismic and Molecular Evolution (IOME), Department of Biology, Johannes Gutenberg-University, Saarstraße 21, 55099 Mainz, Germany
| | - Musa Doğan
- Department of Biological Sciences, Middle East Technical University Ankara, Çankaya, P.O. 06800, Turkey
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LaFountain AM, Yuan YW. Evolution: The art of deceptive pollination. Curr Biol 2023; 33:R301-R303. [PMID: 37098331 PMCID: PMC10601782 DOI: 10.1016/j.cub.2023.03.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Beetle daisies evolved floral spots that mimic female bee flies to entice mate-seeking males for pollination. A new study shows that these deceptive spots emerged through stepwise co-option of multiple genetic elements, shedding light on the origin of complex phenotypic novelties.
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Affiliation(s)
- Amy M LaFountain
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, USA.
| | - Yao-Wu Yuan
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, USA
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Kellenberger RT, Ponraj U, Delahaie B, Fattorini R, Balk J, Lopez-Gomollon S, Müller KH, Ellis AG, Glover BJ. Multiple gene co-options underlie the rapid evolution of sexually deceptive flowers in Gorteria diffusa. Curr Biol 2023; 33:1502-1512.e8. [PMID: 36963385 DOI: 10.1016/j.cub.2023.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/26/2023]
Abstract
Gene co-option, the redeployment of an existing gene in an unrelated developmental context, is an important mechanism underlying the evolution of morphological novelty. In most cases described to date, novel traits emerged by co-option of a single gene or genetic network. Here, we show that the integration of multiple co-opted genetic elements facilitated the rapid evolution of complex petal spots that mimic female bee-fly pollinators in the sexually deceptive South African daisy Gorteria diffusa. First, co-option of iron homeostasis genes altered petal spot pigmentation, producing a color similar to that of female pollinators. Second, co-option of the root hair gene GdEXPA7 enabled the formation of enlarged papillate petal epidermal cells, eliciting copulation responses from male flies. Third, co-option of the miR156-GdSPL1 transcription factor module altered petal spot placement, resulting in better mimicry of female flies resting on the flower. The three genetic elements were likely co-opted sequentially, and strength of sexual deception in different G. diffusa floral forms strongly correlates with the presence of the three corresponding morphological alterations. Our findings suggest that gene co-options can combine in a modular fashion, enabling rapid evolution of novel complex traits.
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Affiliation(s)
- Roman T Kellenberger
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
| | - Udhaya Ponraj
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Boris Delahaie
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; CIRAD, UMR DIADE, Montpellier 34398, France; UMR DIADE, Université de Montpellier, CIRAD, IRD, Montpellier, France
| | - Róisín Fattorini
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Janneke Balk
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich NR4 7UH, UK; School of Biological Sciences, University of East Anglia, Norwich NR4 4JT, UK
| | - Sara Lopez-Gomollon
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Karin H Müller
- Cambridge Advanced Imaging Centre, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Allan G Ellis
- Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Beverley J Glover
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
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Lv Y, Tian T, Wang YJ, Huang JP, Huang SX. Advances in chemistry and bioactivity of the genus Erythroxylum. Nat Prod Bioprospect 2022; 12:15. [PMID: 35426005 PMCID: PMC9010490 DOI: 10.1007/s13659-022-00338-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 03/28/2022] [Indexed: 05/05/2023]
Abstract
Erythroxylum P. Browne is the largest and most representative genus of Erythroxylaceae family. It contains approximately 230 species that are mainly distributed in tropical and subtropical regions. Some species in this genus, such as E. monogynum and E. coca, have been used as folk medicines in India or South America for a long history. It is well known that Erythroxylum plants are rich in tropane alkaloids, and the representative member cocaine shows remarkable activity in human central nervous system. However, many other types of active compounds have also been found in Erythroxylum along with the broadening and deepening of phytochemical research. To date, a total of 383 compounds from Erythroxylum have been reported, among which only 186 tropane alkaloids have been reviewed in 2010. In this review, we summarized all remained 197 compounds characterized from 53 Erythroxylum species from 1960 to 2021, which include diterpenes, triterpenes, alkaloids, flavonoids, and other derivates, providing a comprehensive overview of phytoconstituents profile of Erythroxylum plants. In addition, the biological activities of representative phytochemicals and crude extracts were also highlighted.
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Affiliation(s)
- Yulian Lv
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tian Tian
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yong-Jiang Wang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jian-Ping Huang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
- State Key Laboratory of Southwestern Chinese Medicine Resources, Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Sheng-Xiong Huang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
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Martel C, Rakosy D, Dötterl S, Johnson SD, Ayasse M, Paulus HF, Nilsson LA, Mejlon H, Jersáková J. Specialization for Tachinid Fly Pollination in the Phenologically Divergent Varieties of the Orchid Neotinea ustulata. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.659176] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Despite increased focus on elucidating the various reproductive strategies employed by orchids, we still have only a rather limited understanding of deceptive pollination systems that are not bee- or wasp-mediated. In Europe, the orchid Neotinea ustulata has been known to consist of two phenologically divergent varieties, neither of which provide rewards to its pollinators. However, detailed studies of their reproductive biology have been lacking. Our study aimed to characterize and understand the floral traits (i.e., morphology, color, and scent chemistry) and reproductive biology of N. ustulata. We found that the two varieties differ in all their floral traits; furthermore, while Neotinea ustulata var. ustulata appears to be pollinated by both bees (e.g., Anthophora, Bombus) and flies (e.g., Dilophus, Tachina), var. aestivalis is pollinated almost entirely by flies (i.e., Nowickia, Tachina). Tachinids were also found to be much more effective than bees in removing pollinaria, and we show experimentally that they use the characteristic dark inflorescence top as a cue for approaching inflorescences. Our results thus suggest that while both N. ustulata varieties rely on tachinids for pollination, they differ in their degree of specialization. Further studies are, however, needed to fully understand the reproductive strategy of N. ustulata varieties.
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Ellis AG, Anderson B, Kemp JE. Geographic Mosaics of Fly Pollinators With Divergent Color Preferences Drive Landscape-Scale Structuring of Flower Color in Daisy Communities. Front Plant Sci 2021; 12:617761. [PMID: 33597961 PMCID: PMC7882612 DOI: 10.3389/fpls.2021.617761] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 01/04/2021] [Indexed: 05/10/2023]
Abstract
The striking variation in flower color across and within Angiosperm species is often attributed to divergent selection resulting from geographic mosaics of pollinators with different color preferences. Despite the importance of pollinator mosaics in driving floral divergence, the distributions of pollinators and their color preferences are seldom quantified. The extensive mass-flowering displays of annual daisy species in Namaqualand, South Africa, are characterized by striking color convergence within communities, but also color turnover within species and genera across large geographic scales. We aimed to determine whether shifts between orange and white-flowered daisy communities are driven by the innate color preferences of different pollinators or by soil color, which can potentially affect the detectability of different colored flowers. Different bee-fly pollinators dominated in both community types so that largely non-overlapping pollinator distributions were strongly associated with different flower colors. Visual modeling demonstrated that orange and white-flowered species are distinguishable in fly vision, and choice experiments demonstrated strongly divergent color preferences. We found that the dominant pollinator in orange communities has a strong spontaneous preference for orange flowers, which was not altered by conditioning. Similarly, the dominant pollinator in white communities exhibited an innate preference for white flowers. Although detectability of white flowers varied across soil types, background contrast did not alter color preferences. These findings demonstrate that landscape-level flower color turnover across Namaqua daisy communities is likely shaped by a strong qualitative geographic mosaic of bee-fly pollinators with divergent color preferences. This is an unexpected result given the classically generalist pollination phenotype of daisies. However, because of the dominance of single fly pollinator species within communities, and the virtual absence of bees as pollinators, we suggest that Namaqua daisies function as pollination specialists despite their generalist phenotypes, thus facilitating differentiation of flower color by pollinator shifts across the fly pollinator mosaic.
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Affiliation(s)
- Allan G. Ellis
- Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
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8
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Johnson SD, Sivechurran J, Doarsamy S, Shuttleworth A. Dung mimicry: the function of volatile emissions and corolla patterning in fly-pollinated Wurmbea flowers. New Phytol 2020; 228:1662-1673. [PMID: 33460187 DOI: 10.1111/nph.16791] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 06/26/2020] [Indexed: 06/12/2023]
Abstract
It has been suggested that flowers of some angiosperms mimic vertebrate faeces (dung) in order to exploit insect pollinators that utilize faeces as a source of food and/or oviposition sites. We investigated a potential case of mimicry in Wurmbea elatior (Colchicaceae), a lily that exhibits a faecal odour and pattern of dark spots on the corolla. We found that W. elatior is pollinated by a broad assemblage of coprophagous flies and is dependent on pollinator visits for seed production. The flowers emit volatiles that are characteristic of vertebrate faeces, and three of these compounds - skatole, indole, and an unidentified compound - elicited electrophysiological antennal responses from flies. Artificial flowers laced with indole and skatole or skatole alone attracted the same assemblage of flies as was recorded on flowers of W. elatior. Spotted artificial flowers attracted twice as many flies as did those lacking spots. Experimental addition of indole and skatole to flowers of Wurmbea kraussii, a congener with unscented flowers pollinated by hoverflies, induced a shift to an insect visitor assemblage dominated by coprophagous flies. This study clarifies the roles of volatile emissions (particularly skatole) and visual signals in floral dung mimicry.
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Affiliation(s)
- Steven D Johnson
- Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Post Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa
| | - Jadine Sivechurran
- Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Post Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa
| | - Sachin Doarsamy
- Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Post Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa
| | - Adam Shuttleworth
- Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Post Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa
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Takahashi S, Ozawa S, Sonoike K, Sasaki K, Nishihara M. Morphological and cytological observations of corolla green spots reveal the presence of functional chloroplasts in Japanese gentian. PLoS One 2020; 15:e0237173. [PMID: 32845897 PMCID: PMC7449470 DOI: 10.1371/journal.pone.0237173] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 07/21/2020] [Indexed: 11/19/2022] Open
Abstract
Gentian is an important ornamental flower in Japan. The corolla of the majority of cultivated Japanese gentians have green spots, which are rarely encountered in flowers of other angiosperms. Little information is available on the functional traits of the green spots. In this study, we characterized the green spots in the Japanese gentian corolla using a number of microscopic techniques. Opto-digital microscopy revealed that a single visible green spot is composed of approximately 100 epidermal cells. The epidermal cells of a green spot formed a dome-like structure and the cell lumen contained many green structures that were granular and approximately 5 μm in diameter. The green structures emitted red autofluorescence when irradiated with 488 nm excitation light. Transmission electron microscopy revealed that the green structures contained typical thylakoids and grana, thus indicating they are chloroplasts. No grana were observed and the thylakoids had collapsed in the plastids of epidermal cells surrounding green spots. To estimate the rate of photosynthetic electron transfer of the green spots, we measured chlorophyll fluorescence using the MICROSCOPY version of an Imaging-PAM (pulse-amplitude-modulated) fluorometer. Under actinic light of 449 μmol m-2 s-1, substantial electron flow through photosystem II was observed. Observation of green spot formation during corolla development revealed that immature green spots formed at an early bud stage and developed to maturity associated with chloroplast degradation in the surrounding epidermal cells. These results confirmed that the Japanese gentian corolla contains functional chloroplasts in restricted areas of epidermal cells and indicated that a sophisticated program for differential regulation of chloroplast formation and degradation is operative in the epidermis.
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Affiliation(s)
| | - Suguru Ozawa
- Iwate Agricultural Research Center, Kitakami, Iwate, Japan
| | - Kintake Sonoike
- Faculty of Education and Integrated Arts and Sciences, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Katsutomo Sasaki
- Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
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van der Kooi CJ, Stavenga DG. Vividly coloured poppy flowers due to dense pigmentation and strong scattering in thin petals. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2019; 205:363-372. [PMID: 30689019 PMCID: PMC6579775 DOI: 10.1007/s00359-018-01313-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/19/2018] [Accepted: 12/24/2018] [Indexed: 11/29/2022]
Abstract
The flowers of poppies (Papaveraceae) exhibit bright colours, despite their thin and floppy petals. We investigated the optical properties of flowers of Papaver rhoeas, P. dubium, Meconopsis cambrica and Argemone polyanthemos using a combined approach of anatomy, spectrophotometry and optical modelling. The petals of Papaver flowers are composed of only three cell layers, an upper and lower epidermal layer, which are densely filled with pigment, and an unpigmented mesophyll layer. Dense pigmentation together with strong scattering structures, composed of serpentine cell walls and air cavities, cause the striking poppy colours. We discuss how various aspects of the optical signal contribute to the flower's visibility to pollinators.
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Affiliation(s)
- Casper J van der Kooi
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG, Groningen, The Netherlands.
| | - Doekele G Stavenga
- Computational Physics, Zernike Institute for Advanced Materials, University of Groningen, 9747 AG, Groningen, The Netherlands
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Lebel M, Obolski U, Hadany L, Sapir Y. Pollinator-mediated selection on floral size and tube color in Linum pubescens: Can differential behavior and preference in different times of the day maintain dimorphism? Ecol Evol 2018; 8:1096-1106. [PMID: 29375782 PMCID: PMC5773291 DOI: 10.1002/ece3.3683] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 10/01/2017] [Accepted: 11/08/2017] [Indexed: 12/16/2022] Open
Abstract
Diversity of flower traits is often proposed as the outcome of selection exerted by pollinators. Positive directional pollinator-mediated selection on floral size has been widely shown to reduce phenotypic variance. However, the underlying mechanism of maintaining within-population floral color polymorphism is poorly understood. Divergent selection, mediated by different pollinators or by both mutualists and antagonists, may create and maintain such polymorphism, but it has rarely been shown to result from differential behavior of one pollinator. We tested whether different behaviors of the same pollinators in morning and evening are associated with dimorphic floral trait in Linum pubescens, a Mediterranean annual plant that exhibits variable within-population frequencies of dark- and light-colored flower tubes. Usia bicolor bee-flies, the major pollinators of L. pubescens, are mostly feeding in the flower in the morning, while in the evening they are mostly visiting the flowers for mating. In 2 years of studying L. pubescens in a single large population in the Carmel, Israel, we found in one year that dark-centered flowers received significantly higher fraction of visits in the morning. Fitness was positively affected by number of visits, but no fitness differences were found between tube-color morphs, suggesting that both morphs have similar pollination success. Using mediation analysis, we found that flower size was under positive directional pollinator-mediated selection in both years, but pollinator behavior did not explain entirely this selection, which was possibly mediated also by other agents, such as florivores or a-biotic stresses. While most pollinator-mediated selection studies show that flower size signals food reward, in L. pubescens, it may also signal for mating place, which may drive positive selection. While flower size found to be under pollinator-mediated selection in L. pubescens, differential behavior of the pollinators in morning and evening did not seem to explain flower color polymorphism.
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Affiliation(s)
- Merav Lebel
- The Botanical GardenTel Aviv UniversityTel AvivIsrael
- School of Plant Sciences and Food SecurityTel Aviv UniversityTel AvivIsrael
- Present address:
Science DivisionNature‐Parks AuthorityJerusalemIsrael
| | - Uri Obolski
- The Botanical GardenTel Aviv UniversityTel AvivIsrael
- Present address:
Department of ZoologyUniversity of OxfordOxfordUK
| | - Lilach Hadany
- The Botanical GardenTel Aviv UniversityTel AvivIsrael
| | - Yuval Sapir
- The Botanical GardenTel Aviv UniversityTel AvivIsrael
- School of Plant Sciences and Food SecurityTel Aviv UniversityTel AvivIsrael
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Dieringer G, Cabrera R. L. Pollination and Reproductive Biology in a Hill Prairie Population of Nothocalais cuspidata (Asteraceae: Cichorieae). The American Midland Naturalist 2017. [DOI: 10.1674/0003-0031-177.2.289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Gregg Dieringer
- Department of Natural Sciences, Northwest Missouri State University, Maryville, 64468
| | - Leticia Cabrera R.
- Department of Natural Sciences, Northwest Missouri State University, Maryville, 64468
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de Jager ML, Willis-jones E, Critchley S, Glover BJ. The impact of floral spot and ring markings on pollinator foraging dynamics. Evol Ecol 2017; 31:193-204. [DOI: 10.1007/s10682-016-9852-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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14
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Guerrina M, Casazza G, Conti E, Macrì C, Minuto L. Reproductive biology of an Alpic paleo-endemic in a changing climate. J Plant Res 2016; 129:477-485. [PMID: 26886434 DOI: 10.1007/s10265-016-0796-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 12/13/2015] [Indexed: 06/05/2023]
Abstract
Climate change is known to have a profound influence on plant reproduction, mainly because it affects plant/pollinator interactions, sometimes driving plants to extinction. Starting from the Neogene, the European climate was subjected to severe alterations. Nevertheless, several genera, including Berardia, survived these climatic changes. Despite the numerous studies performed about the relationship between climate change and plant reproductive biology, equivalent studies on ancient species are lacking, even though they may furnish crucial information on the strategies that allowed them to survive drastic climatic fluctuations. We investigated floral and reproductive features in Berardia subacaulis (Asteraceae), describing pollen vectors, capitulum and florets phenology, evaluating reproductive efficiency and defining the reproductive mode of the plant with bagging experiments and test of apomixis. B. subacaulis grows in habitats with low pollination services; it is self-compatible, but many typical features favouring cross-pollination are still present: florets are characterized by incomplete protandry, capitulum protogyny and high pollen-ovule ratio. The plant is not apomictic and self-fertilization is allowed within each capitulum. Similarly to other European Alpine endemics supposed to belong to the Mediterranean ancient tropical flora, the reproductive mode observed in the monospecific genus Berardia assured reproduction also under a pollinator decline. Differently from the other endemics, it took advantage of its spontaneous self-pollination and compatibility and its generalist pollination service, common both among high altitude plants and in the Asteraceae.
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Affiliation(s)
- Maria Guerrina
- DISTAV, Polo Botanico Hanbury, Università degli Studi di Genova, Corso Dogali 1M, 16136, Genoa, Italy
| | - Gabriele Casazza
- DISTAV, Polo Botanico Hanbury, Università degli Studi di Genova, Corso Dogali 1M, 16136, Genoa, Italy
| | - Elena Conti
- Institute of Systematic Botany, Botanic Garden, University of Zurich, Zollikerstrasse 107, 8008, Zurich, Switzerland
| | - Carmelo Macrì
- DISTAV, Polo Botanico Hanbury, Università degli Studi di Genova, Corso Dogali 1M, 16136, Genoa, Italy
| | - Luigi Minuto
- DISTAV, Polo Botanico Hanbury, Università degli Studi di Genova, Corso Dogali 1M, 16136, Genoa, Italy.
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Policha T, Davis A, Barnadas M, Dentinger BTM, Raguso RA, Roy BA. Disentangling visual and olfactory signals in mushroom-mimicking Dracula orchids using realistic three-dimensional printed flowers. New Phytol 2016; 210:1058-1071. [PMID: 26877229 DOI: 10.1111/nph.13855] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 12/01/2015] [Indexed: 06/05/2023]
Abstract
Flowers use olfactory and visual signals to communicate with pollinators. Disentangling the relative contributions and potential synergies between signals remains a challenge. Understanding the perceptual biases exploited by floral mimicry illuminates the evolution of these signals. Here, we disentangle the olfactory and visual components of Dracula lafleurii, which mimics mushrooms in size, shape, color and scent, and is pollinated by mushroom-associated flies. To decouple signals, we used three-dimensional printing to produce realistic artificial flower molds that were color matched and cast using scent-free surgical silicone, to which we could add scent. We used GC-MS to measure scents in co-occurring mushrooms, and related orchids, and used these scents in field experiments. By combining silicone flower parts with real floral organs, we created chimeras that identified the mushroom-like labellum as a source of volatile attraction. In addition, we showed remarkable overlap in the volatile chemistry between D. lafleurii and co-occurring mushrooms. The characters defining the genus Dracula - a mushroom-like, 'gilled' labellum and a showy, patterned calyx - enhance pollinator attraction by exploiting the visual and chemosensory perceptual biases of drosophilid flies. Our techniques for the manipulation of complex traits in a nonmodel system not conducive to gene silencing or selective breeding are useful for other systems.
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Affiliation(s)
- Tobias Policha
- Institute of Ecology & Evolution, 5289 University of Oregon, Eugene, OR, 97403, USA
| | - Aleah Davis
- Institute of Ecology & Evolution, 5289 University of Oregon, Eugene, OR, 97403, USA
| | - Melinda Barnadas
- Department of Visual Arts, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
- Magpie Studio: Fabrication for Art and Science, La Jolla, CA, 92092, USA
| | - Bryn T M Dentinger
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3DS, UK
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Cledwyn Building, Penglais, Aberystwyth, Ceredigion, SY23 3DD, UK
| | - Robert A Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
| | - Bitty A Roy
- Institute of Ecology & Evolution, 5289 University of Oregon, Eugene, OR, 97403, USA
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Brock MT, Lucas LK, Anderson NA, Rubin MJ, Markelz RJC, Covington MF, Devisetty UK, Chapple C, Maloof JN, Weinig C. Genetic architecture, biochemical underpinnings and ecological impact of floral UV patterning. Mol Ecol 2016; 25:1122-40. [PMID: 26800256 DOI: 10.1111/mec.13542] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 12/17/2015] [Accepted: 12/22/2015] [Indexed: 11/29/2022]
Abstract
Floral attraction traits can significantly affect pollinator visitation patterns, but adaptive evolution of these traits may be constrained by correlations with other traits. In some cases, molecular pathways contributing to floral attraction are well characterized, offering the opportunity to explore loci potentially underlying variation among individuals. Here, we quantify the range of variation in floral UV patterning (i.e. UV 'bulls-eye nectar guides) among crop and wild accessions of Brassica rapa. We then use experimental crosses to examine the genetic architecture, candidate loci and biochemical underpinnings of this patterning as well as phenotypic manipulations to test the ecological impact. We find qualitative variation in UV patterning between wild (commonly lacking UV patterns) and crop (commonly exhibiting UV patterns) accessions. Similar to the majority of crops, recombinant inbred lines (RILs) derived from an oilseed crop × WI fast-plant® cross exhibit UV patterns, the size of which varies extensively among genotypes. In RILs, we further observe strong statistical-genetic and QTL correlations within petal morphological traits and within measurements of petal UV patterning; however, correlations between morphology and UV patterning are weak or nonsignificant, suggesting that UV patterning is regulated and may evolve independently of overall petal size. HPLC analyses reveal a high concentration of sinapoyl glucose in UV-absorbing petal regions, which, in concert with physical locations of UV-trait QTLs, suggest a regulatory and structural gene as candidates underlying observed quantitative variation. Finally, insects prefer flowers with UV bulls-eye patterns over those that lack patterns, validating the importance of UV patterning in pollen-limited populations of B. rapa.
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Affiliation(s)
- Marcus T Brock
- Department of Botany, University of Wyoming, Laramie, WY, 82071, USA
| | - Lauren K Lucas
- Department of Biology, Utah State University, Logan, UT, 84322, USA
| | - Nickolas A Anderson
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Matthew J Rubin
- Department of Botany, University of Wyoming, Laramie, WY, 82071, USA
| | - R J Cody Markelz
- Department of Plant Biology, University of California, Davis, CA, 95616, USA
| | - Michael F Covington
- Department of Plant Biology, University of California, Davis, CA, 95616, USA
| | - Upendra K Devisetty
- Department of Plant Biology, University of California, Davis, CA, 95616, USA
| | - Clint Chapple
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Julin N Maloof
- Department of Plant Biology, University of California, Davis, CA, 95616, USA
| | - Cynthia Weinig
- Department of Botany, University of Wyoming, Laramie, WY, 82071, USA.,Department of Molecular Biology, University of Wyoming, Laramie, WY, 82071, USA
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Yuan YW, Rebocho AB, Sagawa JM, Stanley LE, Bradshaw HD Jr. Competition between anthocyanin and flavonol biosynthesis produces spatial pattern variation of floral pigments between Mimulus species. Proc Natl Acad Sci U S A 2016; 113:2448-53. [PMID: 26884205 DOI: 10.1073/pnas.1515294113] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Flower color patterns have long served as a model for developmental genetics because pigment phenotypes are visually striking, yet generally not required for plant viability, facilitating the genetic analysis of color and pattern mutants. The evolution of novel flower colors and patterns has played a key role in the adaptive radiation of flowering plants via their specialized interactions with different pollinator guilds (e.g., bees, butterflies, birds), motivating the search for allelic differences affecting flower color pattern in closely related plant species with different pollinators. We have identified LIGHT AREAS1 (LAR1), encoding an R2R3-MYB transcription factor, as the causal gene underlying the spatial pattern variation of floral anthocyanin pigmentation between two sister species of monkeyflower: the bumblebee-pollinated Mimulus lewisii and the hummingbird-pollinated Mimulus cardinalis. We demonstrated that LAR1 positively regulates FLAVONOL SYNTHASE (FLS), essentially eliminating anthocyanin biosynthesis in the white region (i.e., light areas) around the corolla throat of M. lewisii flowers by diverting dihydroflavonol into flavonol biosynthesis from the anthocyanin pigment pathway. FLS is preferentially expressed in the light areas of the M. lewisii flower, thus prepatterning the corolla. LAR1 expression in M. cardinalis flowers is much lower than in M. lewisii, explaining the unpatterned phenotype and recessive inheritance of the M. cardinalis allele. Furthermore, our gene-expression analysis and genetic mapping results suggest that cis-regulatory change at the LAR1 gene played a critical role in the evolution of different pigmentation patterns between the two species.
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Ellis AG, Brockington SF, de Jager ML, Mellers G, Walker RH, Glover BJ. Floral trait variation and integration as a function of sexual deception in Gorteria diffusa. Philos Trans R Soc Lond B Biol Sci 2015; 369:20130563. [PMID: 25002705 DOI: 10.1098/rstb.2013.0563] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Phenotypic integration, the coordinated covariance of suites of morphological traits, is critical for proper functioning of organisms. Angiosperm flowers are complex structures comprising suites of traits that function together to achieve effective pollen transfer. Floral integration could reflect shared genetic and developmental control of these traits, or could arise through pollinator-imposed stabilizing correlational selection on traits. We sought to expose mechanisms underlying floral trait integration in the sexually deceptive daisy, Gorteria diffusa, by testing the hypothesis that stabilizing selection imposed by male pollinators on floral traits involved in mimicry has resulted in tighter integration. To do this, we quantified patterns of floral trait variance and covariance in morphologically divergent G. diffusa floral forms representing a continuum in the levels of sexual deception. We show that integration of traits functioning in visual attraction of male pollinators increases with pollinator deception, and is stronger than integration of non-mimicry trait modules. Consistent patterns of within-population trait variance and covariance across floral forms suggest that integration has not been built by stabilizing correlational selection on genetically independent traits. Instead pollinator specialization has selected for tightened integration within modules of linked traits. Despite potentially strong constraint on morphological evolution imposed by developmental genetic linkages between traits, we demonstrate substantial divergence in traits across G. diffusa floral forms and show that divergence has often occurred without altering within-population patterns of trait correlations.
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Affiliation(s)
- Allan G Ellis
- Botany and Zoology Department, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Samuel F Brockington
- Department of Plant Sciences, University of Cambridge, Downing St., Cambridge CB2 3EA, UK
| | - Marinus L de Jager
- Botany and Zoology Department, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Gregory Mellers
- Department of Plant Sciences, University of Cambridge, Downing St., Cambridge CB2 3EA, UK
| | - Rachel H Walker
- Department of Plant Sciences, University of Cambridge, Downing St., Cambridge CB2 3EA, UK
| | - Beverley J Glover
- Department of Plant Sciences, University of Cambridge, Downing St., Cambridge CB2 3EA, UK
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Vignolini S, Moyroud E, Hingant T, Banks H, Rudall PJ, Steiner U, Glover BJ. Is floral iridescence a biologically relevant cue in plant-pollinator signalling? A response to van der Kooi et al. (2014b). New Phytol 2015; 205:21-22. [PMID: 25382718 DOI: 10.1111/nph.13178] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Affiliation(s)
- Silvia Vignolini
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
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20
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Lunau K. Visual ecology of flies with particular reference to colour vision and colour preferences. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2014; 200:497-512. [PMID: 24664124 DOI: 10.1007/s00359-014-0895-1] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 02/19/2014] [Accepted: 02/25/2014] [Indexed: 10/25/2022]
Abstract
The visual ecology of flies is outstanding among insects due to a combination of specific attributes. Flies' compound eyes possess an open rhabdom and thus separate rhabdomeres in each ommatidium assigned to two visual pathways. The highly sensitive, monovariant neural superposition system is based on the excitation of the peripheral rhabdomeres of the retinula cells R1-6 and controls optomotor reactions. The two forms of central rhabdomeres of R7/8 retinula cells in each ommatidium build up a system with four photoreceptors sensitive in different wavelength ranges and thought to account for colour vision. Evidence from wavelength discrimination tests suggests that all colour stimuli are assigned to one of just four colour categories, but cooperation of the two pathways is also evident. Flies use colour cues for various behavioural reactions such as flower visitation, proboscis extension, host finding, and egg deposition. Direct evidence for colour vision, the ability to discriminate colours according to spectral shape but independent of intensity, has been demonstrated for few fly species only. Indirect evidence for colour vision provided from electrophysiological recordings of the spectral sensitivity of photoreceptors and opsin genes indicates similar requisites in various flies; the flies' responses to coloured targets, however, are much more diverse.
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de Jager ML, Ellis AG. Floral polymorphism and the fitness implications of attracting pollinating and florivorous insects. Ann Bot 2014; 113:213-22. [PMID: 24052554 PMCID: PMC3890383 DOI: 10.1093/aob/mct189] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 07/02/2013] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND AIMS Floral polymorphism is frequently attributed to pollinator-mediated selection. Multiple studies, however, have revealed the importance of non-pollinating visitors in floral evolution. Using the polymorphic annual daisy Ursinia calenduliflora, this study investigated the importance of different insect visitors, and their effects on fitness, in the maintenance of floral polymorphism. METHODS The spatial structure of a discrete floral polymorphism was characterized based on the presence/absence of anthocyanin floret spots in U. calenduliflora. A 3-year observational study was then conducted in polymorphic populations to investigate differences in visitation rates of dominant visitors to floral morphs. Experiments were performed to explore the floral preference of male and female Megapalpus capensis (the dominant insect visitor) and their effectiveness as pollinators. Next, floral damage by antagonistic florivores and the reproductive success of the two floral morphs were surveyed in multiple populations and years. KEY RESULTS Floral polymorphism in U. calenduliflora was structured spatially, as were insect visitation patterns. Megapalpus capensis males were the dominant visitors and exhibited strong preference for the spotted morph in natural and experimental observations. While this may indicate potential fitness benefits for the spotted morph, female fitness did not differ between floral morphs. However, as M. capensis males are very efficient at exporting U. calenduliflora pollen, their preference may likely increase the reproductive fitness of the spotted morph through male fitness components. The spotted morph, however, also suffered significantly greater costs due to ovule predation by florivores than the spotless morph. CONCLUSIONS The results suggest that pollinators and florivores may potentially exert antagonistic selection that could contribute to the maintenance of floral polymorphism across the range of U. calenduliflora. The relative strength of selection imposed by each agent is potentially determined by insect community composition and abundance at each site, highlighting the importance of community context in the evolution of floral phenotypes.
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Affiliation(s)
- Marinus L. de Jager
- Botany and Zoology Department, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
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23
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Whitney HM, Milne G, Rands SA, Vignolini S, Martin C, Glover BJ. The influence of pigmentation patterning on bumblebee foraging from flowers of Antirrhinum majus. Naturwissenschaften 2013; 100:249-56. [DOI: 10.1007/s00114-013-1020-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 01/21/2013] [Accepted: 01/24/2013] [Indexed: 11/28/2022]
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Martins TR, Berg JJ, Blinka S, Rausher MD, Baum DA. Precise spatio-temporal regulation of the anthocyanin biosynthetic pathway leads to petal spot formation in Clarkia gracilis (Onagraceae). New Phytol 2013; 197:958-969. [PMID: 23231386 PMCID: PMC3540125 DOI: 10.1111/nph.12062] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 10/19/2012] [Indexed: 05/18/2023]
Abstract
Petal spots are widespread in angiosperms and are often implicated in pollinator attraction. Clarkia gracilis petals each have a single red-purple spot that contrasts against a pink background. The position and presence of spots in C. gracilis are determined by the epistatic interaction of alleles at two as yet unidentified loci. We used HPLC to identify the different pigments produced in the petals, and qualitative and quantitative RT-PCR to assay for spatio-temporal patterns of expression of different anthocyanin pathway genes. We found that spots contain different pigments from the remainder of the petal, being composed of cyanidin/peonidin-based, instead of malvidin-based anthocyanins. Expression assays of anthocyanin pathway genes showed that the dihydroflavonol-4-reductase 2 (Dfr2) gene has a spot-specific expression pattern and acts as a switch for spot production. Co-segregation analyses implicated the gene products of the P and I loci as trans-regulators of this switch. Spot pigments appear earlier in development as a result of early expression of Dfr2 and the flavonoid 3' hydroxylase 1 (F3'h1) gene. Pigments in the background appear later, as a result of later expression of Dfr1 and the flavonoid 3'-5' hydroxylase 1 (F3'5'h1) genes. The evolution of this spot production mechanism appears to have been facilitated by duplication of the Dfr gene and to have required substantial reworking of the anthocyanin pathway regulatory network.
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Affiliation(s)
- Talline R. Martins
- Department of Botany, University of Wisconsin, Madison, Wisconsin 53706
- Department of Biology, Duke University, Durham, North Carolina 27708
| | - Jeremy J. Berg
- Department of Botany, University of Wisconsin, Madison, Wisconsin 53706
| | - Steven Blinka
- Department of Botany, University of Wisconsin, Madison, Wisconsin 53706
| | - Mark D. Rausher
- Department of Biology, Duke University, Durham, North Carolina 27708
| | - David A. Baum
- Department of Botany, University of Wisconsin, Madison, Wisconsin 53706
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Affiliation(s)
- Marinus L. de Jager
- Department of Botany and Zoology; Stellenbosch University; Private Bag X1; Matieland; 7602; South Africa
| | - Allan G. Ellis
- Department of Botany and Zoology; Stellenbosch University; Private Bag X1; Matieland; 7602; South Africa
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26
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Ellis AG, Johnson SD. Lack of floral constancy by bee fly pollinators: implications for ethological isolation in an African daisy. Behav Ecol 2012. [DOI: 10.1093/beheco/ars019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Teixido AL, Méndez M, Valladares F. Flower size and longevity influence florivory in the large-flowered shrub Cistus ladanifer. Acta Oecologica 2011. [DOI: 10.1016/j.actao.2011.05.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Ellis AG, Johnson SD. Floral mimicry enhances pollen export: the evolution of pollination by sexual deceit outside of the orchidaceae. Am Nat 2011; 176:E143-51. [PMID: 20843263 DOI: 10.1086/656487] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Although the majority of flowering plants achieve pollination by exploiting the food‐seeking behavior of animals, some use alternative ploys that exploit their mate‐seeking behavior. Sexual deception is currently known only from the Orchidaceae and almost always involves pollination by male hymenoptera. An outstanding problem has been to identify the selective factors in plants that favor exploitation of mating versus feeding behaviors in pollinators. Here we show that the insectlike petal ornaments on inflorescences of the daisy Gorteria diffusa elicit copulation attempts from male bombyliid flies and that the intensity of the mating response varies across geographical floral morphotypes, suggesting a continuum in reliance on feeding through mating responses for pollination. Using pollen analogues applied to a morphotype with prominent insectlike petal ornaments, we demonstrate that mate‐seeking male flies are several‐fold more active and export significantly more pollen than females. These results suggest that selection for traits that exploit insect mating behavior can occur through the male component of plant fitness and conclusively demonstrates pollination by sexual deception in Gorteria, making this the first confirmed report of sexual deception outside of the Orchidaceae.
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Affiliation(s)
- Allan G Ellis
- School of Biological and Conservation Sciences, University of KwaZulu‐Natal, Scottsville, Pietermaritzburg 3209, South Africa.
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KEASAR TAMAR, HARARI ALLYR, SABATINELLI GUIDO, KEITH DENIS, DAFNI AMOTS, SHAVIT OFRIT, ZYLBERTAL ASAPH, SHMIDA AVI. Red anemone guild flowers as focal places for mating and feeding by Levant glaphyrid beetles. Biol J Linn Soc Lond 2010. [DOI: 10.1111/j.1095-8312.2010.01384.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
The flora of southern Africa has exceptional species richness and endemism, making it an ideal system for studying the patterns and processes of evolutionary diversification. Using a wealth of recent case studies, I examine the evidence for pollinator-driven diversification in this flora. Pollination systems, which represent available niches for ecological diversification, are characterized in southern Africa by a high level of ecological and evolutionary specialization on the part of plants, and, in some cases, by pollinators as well. These systems are asymmetric, with entire plant guilds commonly specialized for a particular pollinator species or functional type, resulting in obvious convergent floral evolution among guild members. Identified modes of plant lineage diversification involving adaptation to pollinators in these guilds include (i) shifts between pollination systems, (ii) divergent use of the same pollinator, (iii) coevolution, (iv) trait tracking, and (v) floral mimicry of different model species. Microevolutionary studies confirm that pollinator shifts can be precipitated when a plant species encounters a novel pollinator fauna on its range margin, and macroevolutionary studies confirm frequent pollinator shifts associated with lineage diversification. As Darwin first noted, evolutionary specialization for particular pollinators, when resulting in ecological dependency, may increase the risk of plant extinction. I thus also consider the evidence that disturbance provokes pollination failure in some southern African plants with specialized pollination systems.
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Affiliation(s)
- Steven D Johnson
- School of Biological and Conservation Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg 3209, South Africa.
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33
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Johnson SD. The pollination niche and its role in the diversification and maintenance of the southern African flora. Philos Trans R Soc Lond B Biol Sci 2010. [PMID: 20047876 DOI: 10.1098/rstb.2009.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023] Open
Abstract
The flora of southern Africa has exceptional species richness and endemism, making it an ideal system for studying the patterns and processes of evolutionary diversification. Using a wealth of recent case studies, I examine the evidence for pollinator-driven diversification in this flora. Pollination systems, which represent available niches for ecological diversification, are characterized in southern Africa by a high level of ecological and evolutionary specialization on the part of plants, and, in some cases, by pollinators as well. These systems are asymmetric, with entire plant guilds commonly specialized for a particular pollinator species or functional type, resulting in obvious convergent floral evolution among guild members. Identified modes of plant lineage diversification involving adaptation to pollinators in these guilds include (i) shifts between pollination systems, (ii) divergent use of the same pollinator, (iii) coevolution, (iv) trait tracking, and (v) floral mimicry of different model species. Microevolutionary studies confirm that pollinator shifts can be precipitated when a plant species encounters a novel pollinator fauna on its range margin, and macroevolutionary studies confirm frequent pollinator shifts associated with lineage diversification. As Darwin first noted, evolutionary specialization for particular pollinators, when resulting in ecological dependency, may increase the risk of plant extinction. I thus also consider the evidence that disturbance provokes pollination failure in some southern African plants with specialized pollination systems.
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Affiliation(s)
- Steven D Johnson
- School of Biological and Conservation Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg 3209, South Africa.
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Thomas MM, Rudall PJ, Ellis AG, Savolainen V, Glover BJ. Development of a complex floral trait: The pollinator-attracting petal spots of the beetle daisy, Gorteria diffusa (Asteraceae). Am J Bot 2009; 96:2184-96. [PMID: 21622334 DOI: 10.3732/ajb.0900079] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Angiosperms possess a variety of complex floral traits that attract animal pollinators. Dark petal spots have evolved independently many times across the angiosperm phylogeny and have been shown to attract insect pollinators from several lineages. Here we present new data on the ontogeny and morphological complexity of the elaborate insect-mimicking petal spots of the South African daisy species, Gorteria diffusa (Asteraceae), commonly known as the beetle daisy, although it is fly-pollinated. Using light and scanning electron microscopy and histology, we identified three distinct specialized cell types of the petal epidermis that compose the petal spot. Sophisticated patterning of pigments, cuticular elaborations, and multicellular papillate trichomes make the G. diffusa petal spot a uniquely complex three-dimensional floral ornament. Examination of young inflorescence meristems revealed that G. diffusa ray florets develop (and probably also initiate) basipetally, in the opposite direction to the disc florets-a developmental phenomenon that has been found in some other daisies, but which contradicts conventional theories of daisy inflorescence architecture. Using these ontogenetic and morphological data, we have identified the mechanism by which G. diffusa patterns its insect-mimicking petal spots, and we propose a testable model for the genetic regulation of petal spot identity.
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Affiliation(s)
- Meredith M Thomas
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
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Abstract
One of the most widely accepted explanations for floral diversification in angiosperms is the pollinator-shift model developed by Verne Grant and Ledyard Stebbins. According to this model, the most profound changes in floral traits (such as morphology, color, patterning and scent) occur when plants undergo adaptive shifts between pollinator classes. We tested this model through investigations of geographical variation in floral form and pollinator assemblages in the South African annual daisy Gorteria diffusa. This species has elaborate insect-like ornaments on the capitulum, which attract bee flies belonging to the genus Megapalpus. We found unprecedented levels of geographically structured intraspecific variation and identified 14 discrete forms that vary in the morphology and ornamentation of the capitulum. This variation is not due to phenotypic plasticity because differences among forms were maintained in plants grown from seed in a common garden experiment. Contrary to predictions from the pollinator-shift model, all populations, regardless of floral phenotype, were pollinated primarily by a single species of Megapalpus bee fly. Much of the extensive variation in floral form in G. diffusa therefore appears to have arisen without evolutionary shifts between pollinator types.
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Affiliation(s)
- Allan G Ellis
- School of Biological and Conservation Sciences, University of KwaZulu-Natal, P Bag X01, Scottsville, Pietermaritzburg 3209, South Africa
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Sugiura S, Abe T, Yamaura Y, Makino S. Flower-visiting behavior of male bees is triggered by nectar-feeding insects. Naturwissenschaften 2007; 94:703-7. [PMID: 17440704 DOI: 10.1007/s00114-007-0246-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2006] [Revised: 03/07/2007] [Accepted: 03/09/2007] [Indexed: 11/29/2022]
Abstract
Bees are important pollinators for many flowering plants. Female bees are thought to be more effective pollinators than male bees because they carry much more pollen than males. Males of some solitary bee species are known to patrol near flowers that females visit. Because patrolling males visit flowers to mate or defend their territories, they may function as pollinators. However, the significance of patrolling males to pollination has not been studied. We studied males of a solitary bee, Heriades fulvohispidus (Megachilidae), patrolling near flowers and visiting flowers that attracted nectar-feeding insects, including conspecifics, on the Ogasawara (Bonin) Islands. To test the hypothesis that patrolling male bees may function as pollen vectors, we compared the frequency of visits by H. fulvohispidus to flowers of an endemic plant, Schima mertensiana (Theaceae); comparisons were made among flowers with a dead H. fulvohispidus, a dead beetle, a piece of plastic, and nothing (control flowers). Patrolling H. fulvohispidus more frequently visited flowers with a dead conspecific, a dead beetle, or a piece of plastic than the control flowers. Our experiment demonstrates that nectar-feeding insects (including conspecifics and other insects) enhance the flower-visiting frequency of patrolling H. fulvohispidus males on S. mertensiana flowers. Furthermore, we observed S. mertensiana pollen on patrolling males as well as females, suggesting that male bees may also function as pollen vectors.
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Affiliation(s)
- Shinji Sugiura
- Forestry and Forest Products Research Institute (FFPRI), 1 Matsunosato, Tsukuba, Ibaraki, 305-8687, Japan.
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Jersáková J, Johnson SD, Kindlmann P. Mechanisms and evolution of deceptive pollination in orchids. Biol Rev Camb Philos Soc 2006; 81:219-35. [PMID: 16677433 DOI: 10.1017/s1464793105006986] [Citation(s) in RCA: 241] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Revised: 11/04/2005] [Accepted: 11/21/2005] [Indexed: 11/06/2022]
Abstract
The orchid family is renowned for its enormous diversity of pollination mechanisms and unusually high occurrence of non-rewarding flowers compared to other plant families. The mechanisms of deception in orchids include generalized food deception, food-deceptive floral mimicry, brood-site imitation, shelter imitation, pseudoantagonism, rendezvous attraction and sexual deception. Generalized food deception is the most common mechanism (reported in 38 genera) followed by sexual deception (18 genera). Floral deception in orchids has been intensively studied since Darwin, but the evolution of non-rewarding flowers still presents a major puzzle for evolutionary biology. The two principal hypotheses as to how deception could increase fitness in plants are (i) reallocation of resources associated with reward production to flowering and seed production, and (ii) higher levels of cross-pollination due to pollinators visiting fewer flowers on non-rewarding plants, resulting in more outcrossed progeny and more efficient pollen export. Biologists have also tried to explain why deception is overrepresented in the orchid family. These explanations include: (i) efficient removal and deposition of pollinaria from orchid flowers in a single pollinator visit, thus obviating the need for rewards to entice multiple visits from pollinators; (ii) efficient transport of orchid pollen, thus requiring less reward-induced pollinator constancy; (iii) low-density populations in many orchids, thus limiting the learning of associations of floral phenotypes and rewards by pollinators; (iv) packaging of pollen in pollinaria with limited carry-over from flower to flower, thus increasing the risks of geitonogamous self-pollination when pollinators visit many flowers on rewarding plants. All of these general and orchid-specific hypotheses are difficult to reconcile with the well-established pattern for rewardlessness to result in low pollinator visitation rates and consequently low levels of fruit production. Arguments that deception evolves because rewards are costly are particularly problematic in that small amounts of nectar are unlikely to have a significant effect on the energy budget of orchids, and because reproduction in orchids is often severely pollen-, rather than resource-limited. Several recent experimental studies have shown that deception promotes cross-pollination, but it remains unknown whether actual outcrossing rates are generally higher in deceptive orchids. Our review of the literature shows that there is currently no evidence that deceptive orchids carry higher levels of genetic load (an indirect measure of outcrossing rate) than their rewarding counterparts. Cross-pollination does, however, result in dramatic increases in seed quality in almost all orchids and has the potential to increase pollen export (by reducing pollen discounting). We suggest that floral deception is particularly beneficial, because of its promotion of outcrossing, when pollinators are abundant, but that when pollinators are consistently rare, selection may favour a nectar reward or a shift to autopollination. Given that nectar-rewardlessness is likely to have been the ancestral condition in orchids and yet is evolutionarily labile, more attention will need to be given to explanations as to why deception constitutes an 'evolutionarily stable strategy'.
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Affiliation(s)
- Jana Jersáková
- School of Biological and Conservation Sciences, University of KwaZulu-Natal, Private Bag X01, Pietermaritzburg, 3209, South Africa
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M. Eckhart V, S. Rushing N, M. Hart G, D. Hansen J. Frequency-dependent pollinator foraging in polymorphicClarkia xantianassp.xantianapopulations: implications for flower colour evolution and pollinator interactions. OIKOS 2006. [DOI: 10.1111/j.0030-1299.2006.14289.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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JOHNSON STEVEND, ALEXANDERSSON RONNY, LINDER HPETER. Experimental and phylogenetic evidence for floral mimicry in a guild of fly-pollinated plants. Biol J Linn Soc Lond 2003. [DOI: 10.1046/j.1095-8312.2003.00236.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
In order to further characterize the function of coloration in plants as defense against herbivory, two types of thorn mimicry are described: (1) A unique type of weapon (thorn) automimicry (within the same individual) that was previously known only in animals, and (2) mimicry of aposematic colorful thorns, by colorful elongated and pointed plant organs (buds, leaves and fruit) that, despite their appearance, are not sharp. Some thorny plants including dozens of species of Agave, one species of Aloe and a palm species have thorn-like imprints or colorations on their leaves, constituting thorn automimicry by giving the impression of more extensive thorns. The mimicry of aposematic colorful thorns is a typical case of Batesian mimicry, but the thorn automimicry is a special intra-organismic Batesian mimicry. I propose that both types of mimicry serve as anti-herbivore mechanisms.
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Affiliation(s)
- Simcha Lev-Yadun
- Department of Biology, Faculty of Science and Science Education, University of Haifa-Oranim, Tivon, 36006, Israel.
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Lamborn E, Ollerton J. Experimental assessment of the functional morphology of inflorescences of Daucus carota
(Apiaceae): testing the ‘fly catcher effect’. Funct Ecol 2001. [DOI: 10.1046/j.1365-2435.2000.00440.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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