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Werchan M, Werchan B, Bogawski P, Mousavi F, Metz M, Bergmann KC. An emerging aeroallergen in Europe: Tree-of-Heaven (Ailanthus altissima [Mill.] Swingle) inventory and pollen concentrations - Taking a metropolitan region in Germany as an example. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 930:172519. [PMID: 38636870 DOI: 10.1016/j.scitotenv.2024.172519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 03/28/2024] [Accepted: 04/14/2024] [Indexed: 04/20/2024]
Abstract
Urban areas are often hotspots for the dissemination of non-native (invasive) plant species, some of which release (potentially) allergenic pollen. Given the high population density in cities, a considerable number of people can be regularly and potentially intensively exposed to the pollen from these plants. This study delves into the Tree-of-Heaven (Ailanthus altissima, [Mill.] Swingle), native to East Asia, which is known for its high invasiveness in temperate regions worldwide, particularly favoring urban colonization. This study explores the botanical and aerobiological dimensions of this species using the central European metropolitan region of Berlin, Germany, as a case study, and provides a comprehensive global overview of allergological insights. The number of Ailanthus trees decreased markedly from the center to the periphery of Berlin City, following a temperature gradient. The same spatial trend was mirrored by airborne Ailanthus pollen concentrations measured with volumetric spore traps (Hirst-type) at five sites using seven traps. Ailanthus pollen was most abundant around midday and in the afternoon, with concentrations tenfold higher at street level than at roof level. The Ailanthus flowering period in June and July coincided well with the pollen season. To the best of our knowledge this is the first study to investigate Ailanthus altissima pollen production. On average, 5539 pollen grains were found per anther. A literature review on the allergy relevance of Ailanthus altissima pollen indicates the high allergenic potential of pollen from this species. Considering the anticipated expansion of suitable habitats for Ailanthus owing to global warming and the allergological significance of its pollen, it is recommended to include Ailanthus pollen in routine pollen monitoring, particularly in areas colonized by this species. This comprehensive study provides new insights into a pollen taxon whose significance as an emerging aeroallergen should be factored into plant selection and greenspace management in all temperate regions.
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Affiliation(s)
- Matthias Werchan
- German Pollen Information Service Foundation, Berlin, Germany; Institute of Allergology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
| | - Barbora Werchan
- German Pollen Information Service Foundation, Berlin, Germany
| | - Paweł Bogawski
- Adam Mickiewicz University, Poznań, Faculty of Biology, Department of Systematic and Environmental Botany, Poznań, Poland
| | - Fateme Mousavi
- Air and Space Physiology Research Group, Aerospace Research Institute, Ministry of Science Research and Technology, Tehran, Iran
| | - Martin Metz
- Institute of Allergology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany; Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology, Berlin, Germany
| | - Karl-Christian Bergmann
- German Pollen Information Service Foundation, Berlin, Germany; Institute of Allergology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
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Abrahamczyk S, Struck JH, Weigend M. The best of two worlds: ecology and evolution of ambophilous plants. Biol Rev Camb Philos Soc 2023; 98:391-420. [PMID: 36270973 DOI: 10.1111/brv.12911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 10/05/2022] [Accepted: 10/05/2022] [Indexed: 11/29/2022]
Abstract
Ambophily, the mixed mode of wind and insect pollination is still poorly understood, even though it has been known to science for over 130 years. While its presence has been repeatedly inferred, experimental data remain regrettably rare. No specific suite of morphological or ecological characteristics has yet been identified for ambophilous plants and their ecology and evolution remain uncertain. In this review we summarise and evaluate our current understanding of ambophily, primarily based on experimental studies. A total of 128 ambophilous species - including several agriculturally important crops - have been reported from most major habitat types worldwide, but this probably represents only a small subset of ambophilous species. Ambophilous species have evolved both from wind- and insect-pollinated ancestors, with insect-pollinated ancestors mostly representing pollination by small, generalist flower visitors. We compiled floral and reproductive traits for known ambophilous species and compared our results to traits of species pollinated either by wind or by small generalist insects only. Floral traits were found to be heterogeneous and strongly overlap especially with those of species pollinated by small generalist insects, which are also the prominent pollinator group for ambophilous plants. A few ambophilous species are only pollinated by specialised bees or beetles in addition to pollination by wind. The heterogeneity of floral traits and high similarity to generalist small insect-pollinated species lead us to conclude that ambophily is not a separate pollination syndrome but includes species belonging to different insect- as well as wind-pollination syndromes. Ambophily therefore should be regarded as a pollination mode. We found that a number of ecological factors promoted the evolution of ambophily, including avoidance of pollen limitation and self-pollination, spatial flower interference and population density. However, the individual ecological factors favouring the transition to ambophily vary among species depending on species distribution, habitat, population structure and reproductive system. Finally, a number of experimental studies in combination with observations of floral traits of living and fossil species and dated phylogenies may indicate evolutionary stability. In some clades ambophily has likely prevailed for millions of years, for example in the castanoid clade of the Fagaceae.
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Affiliation(s)
- Stefan Abrahamczyk
- Botany Department, State Museum of Natural History Stuttgart, Rosenstein 1, 70191, Stuttgart, Germany
- Nees Institute for Biodiversity of Plants, University of Bonn, Meckenheimer Allee 170, 53113, Bonn, Germany
| | - Jan-Hendrik Struck
- Nees Institute for Biodiversity of Plants, University of Bonn, Meckenheimer Allee 170, 53113, Bonn, Germany
| | - Maximilian Weigend
- Nees Institute for Biodiversity of Plants, University of Bonn, Meckenheimer Allee 170, 53113, Bonn, Germany
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Wu L, Xu H, Jian S, Gong X, Feng X. Geographic factors and climatic fluctuation drive the genetic structure and demographic history of
Cycas taiwaniana
(Cycadaceae), an endemic endangered species to Hainan Island in China. Ecol Evol 2022; 12:e9508. [DOI: 10.1002/ece3.9508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 10/14/2022] [Accepted: 10/27/2022] [Indexed: 11/20/2022] Open
Affiliation(s)
- Li‐Xin Wu
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany Chinese Academy of Sciences Kunming China
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany Chinese Academy of Sciences Kunming China
- University of Chinese Academy of Science Beijing China
- Plant Science Institute, School of Life Sciences Yunnan University Kunming China
| | - Hai‐Yan Xu
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany Chinese Academy of Sciences Kunming China
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany Chinese Academy of Sciences Kunming China
- University of Chinese Academy of Science Beijing China
| | - Shu‐Guang Jian
- CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones, South China Botanical Garden Chinese Academy of Sciences Guangzhou China
| | - Xun Gong
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany Chinese Academy of Sciences Kunming China
| | - Xiu‐Yan Feng
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany Chinese Academy of Sciences Kunming China
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Gómez-Noguez F, Domínguez-Ugalde C, Flores-Galván C, León-Rossano LM, García BP, Mendoza-Ruiz A, Rosas-Pérez I, Mehltreter K. Terminal velocity of fern and lycopod spores is affected more by mass and ornamentation than by size. AMERICAN JOURNAL OF BOTANY 2022; 109:1221-1229. [PMID: 35903036 DOI: 10.1002/ajb2.16041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 07/04/2022] [Accepted: 07/05/2022] [Indexed: 06/15/2023]
Abstract
PREMISE Terminal velocity (Vt) is an important factor for the dispersal of biological particles but has scarcely been studied for anemochorous fern spores, and the influence of spore characteristics on Vt has not been evaluated. Here, we measured the Vt of 1234 spores of 18 fern species and two Selaginella microspores using videoimaging analysis and evaluated the effects of mass, size, and ornamentation on Vt. METHODS We designed a sedimentation tower with a graduated microtelescope attached to a high-speed video camera to record falling particles and measure the Vt of fern spores using video-image processing software. Spores were measured for each species and their size correlated with Vt. RESULTS The Vt of fern spores ranged from 4.7 cm·s-1 (Cyathea costaricensis) to 18.85 cm·s-1 (Acrostichum danaeifolium). The method is accurate and reliable as predicted by Stokes model for glass beads of known density and size. In addition, Vt had a higher correlation coefficient with mass (ρ = 0.72) than size (ρ = 0.20), and ornamental appendages reduced Vt. CONCLUSIONS The reported values of Vt of fern spores are within the range of different biological airborne particles such as moss spores and pollen grains of seed plants. The results showed that spore ornamentation is directly related to Vt rather than spore size and may increase or decrease the drag. This method will aid future aerobiological research on biological particles.
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Affiliation(s)
- Felipe Gómez-Noguez
- Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Av. Lázaro Cárdenas s/n, Ciudad Universitaria Sur, Chilpancingo de los Bravo, Guerrero, 39086, México
| | - César Domínguez-Ugalde
- Licenciatura en Biología, Universidad Autónoma Metropolitana-Iztapalapa, Av. Ferrocarril de San Rafael Atlixco 186, Col. Leyes de Reforma 1ª Sección, Ciudad de México, 09310, México
| | - Catalina Flores-Galván
- Red de Ecología Funcional, Instituto de Ecología A. C. Carretera Antigua a Coatepec No. 351, El Haya, Xalapa, Veracruz, 91073, México
| | - Luis Manuel León-Rossano
- Departamento de Física, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, 04510, México
| | - Blanca Pérez García
- Área de Botánica Estructural y Sistemática Vegetal, Departamento de Biología, Universidad Autónoma Metropolitana-Iztapalapa, Av. Ferrocarril de San Rafael Atlixco 186, Col. Leyes de Reforma 1ª Sección, Ciudad de México, 09310, México
| | - Aniceto Mendoza-Ruiz
- Área de Botánica Estructural y Sistemática Vegetal, Departamento de Biología, Universidad Autónoma Metropolitana-Iztapalapa. Av. Ferrocarril de San Rafael Atlixco 186, Col. Leyes de Reforma 1ª Sección, Ciudad de México, 09310, México
| | - Irma Rosas-Pérez
- Instituto de Ciencias de la Atmósfera y Cambio Climático, Universidad Nacional Autónoma de México, Circuito exterior s/n, Coyoacán, Ciudad Universitaria, Ciudad de México, 04510, México
| | - Klaus Mehltreter
- Red de Ecología Funcional, Instituto de Ecología A. C. Carretera Antigua a Coatepec No. 351, El Haya, Xalapa, Veracruz, 91073, México
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Timerman D, Barrett SCH. The biomechanics of pollen release: new perspectives on the evolution of wind pollination in angiosperms. Biol Rev Camb Philos Soc 2021; 96:2146-2163. [PMID: 34076950 DOI: 10.1111/brv.12745] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 05/07/2021] [Accepted: 05/11/2021] [Indexed: 11/30/2022]
Abstract
Evolutionary transitions from animal to wind pollination have occurred repeatedly during the history of the angiosperms, but the selective mechanisms remain elusive. Here, we propose that knowledge of pollen release biomechanics is critical for understanding the ecological and evolutionary processes underpinning this shift in pollination mode. Pollen release is the critical first stage of wind pollination (anemophily) and stamen properties are therefore likely to be under strong selection early in the transition. We describe current understanding of pollen release biomechanics to provide insights on the phenotypic and ecological drivers of wind pollination. Pollen release occurs when detachment forces dominate resistive forces retaining pollen within anthers. Detachment forces can be active or passive depending on whether they require energy input from the environment. Passive release is more widespread in anemophilous species and involves processes driven by steady or unsteady aerodynamic forces or turbulence-induced vibrations that shake pollen from anthers. We review empirical and theoretical studies suggesting that stamen vibration is likely to be a key mechanism of pollen release. The vibration response is governed by morphological and biomechanical properties of stamens, which may undergo divergent selection in the presence or absence of pollinators. Resistive forces have rarely been investigated for pollen within anthers, but are probably sensitive to environmental conditions and depend on flower age, varying systematically between animal- and wind-pollinated species. Animal and wind pollination are traditionally viewed as dichotomous alternatives because they are usually associated with strikingly different pollination syndromes. But this perspective has diverted attention from subtler, continuously varying traits which mediate the fluid dynamic process of pollen release. Reinterpreting the flower as a biomechanical entity that responds to fluctuating environmental forces may provide a promising way forward. We conclude by identifying several profitable areas for future research to obtain deeper insight into the evolution of wind pollination.
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Affiliation(s)
- David Timerman
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, M5S 3B2, Canada
| | - Spencer C H Barrett
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, M5S 3B2, Canada
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Kenđel A, Zimmermann B. Chemical Analysis of Pollen by FT-Raman and FTIR Spectroscopies. FRONTIERS IN PLANT SCIENCE 2020; 11:352. [PMID: 32296453 PMCID: PMC7136416 DOI: 10.3389/fpls.2020.00352] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 03/10/2020] [Indexed: 05/13/2023]
Abstract
Pollen studies are important for the assessment of present and past environment, including biodiversity, sexual reproduction of plants and plant-pollinator interactions, monitoring of aeroallergens, and impact of climate and pollution on wild communities and cultivated crops. Although information on chemical composition of pollen is of importance in all of those research areas, pollen chemistry has been rarely measured due to complex and time-consuming analyses. Vibrational spectroscopies, coupled with multivariate data analysis, have shown great potential for rapid chemical characterization, identification and classification of pollen. This study, comprising 219 species from all principal taxa of seed plants, has demonstrated that high-quality Raman spectra of pollen can be obtained by Fourier transform (FT) Raman spectroscopy. In combination with Fourier transform infrared spectroscopy (FTIR), FT-Raman spectroscopy is obtaining comprehensive information on pollen chemistry. Presence of all the main biochemical constituents of pollen, such as proteins, lipids, carbohydrates, carotenoids and sporopollenins, have been identified and detected in the spectra, and the study shows approaches to measure relative and absolute content of these constituents. The results show that FT-Raman spectroscopy has clear advantage over standard dispersive Raman measurements, in particular for measurement of pollen samples with high pigment content. FT-Raman spectra are strongly biased toward chemical composition of pollen wall constituents, namely sporopollenins and pigments. This makes Raman spectra complementary to FTIR spectra, which over-represent chemical constituents of the grain interior, such as lipids and carbohydrates. The results show a large variability in pollen chemistry for families, genera and even congeneric species, revealing wide range of reproductive strategies, from storage of nutrients to variation in carotenoids and phenylpropanoids. The information on pollen's chemical patterns for major plant taxa should be of outstanding value for various studies in plant biology and ecology, including aerobiology, palaeoecology, forensics, community ecology, plant-pollinator interactions, and climate effects on plants.
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Affiliation(s)
- Adriana Kenđel
- Division of Analytical Chemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Boris Zimmermann
- Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, Norway
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Zagreb, Croatia
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Xiao S, Ji Y, Liu J, Gong X. Genetic characterization of the entire range of Cycas panzhihuaensis (Cycadaceae). PLANT DIVERSITY 2020; 42:7-18. [PMID: 32140633 PMCID: PMC7046506 DOI: 10.1016/j.pld.2019.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 10/03/2019] [Accepted: 10/08/2019] [Indexed: 06/10/2023]
Abstract
Cycas panzhihuaensis L. Zhou & S. Y. Yang (Cycadaceae) is an endangered gymnosperm species endemic to the dry-hot valley of the Jinsha River basin in southwest China. Although the wild C. panzhihuaensis population from Panzhihua Cycad Natural Reserve is well protected and its genetic diversity has been well assessed, the genetic characteristics of populations outside the nature reserve, which face larger risks of extinction, remain unknown. Furthermore, the population genetics and historical dynamics of this endemic and endangered species have not been examined across its entire range. In this study, to analyze the genetic diversity, phylogeographical structure and demographic history of C. panzhihuaensis from all its seven known locations, we sequenced and compared molecular data from chloroplastic DNA (psbA-trnH, psbM-trnD, and trnS-trnG), single-copy nuclear genes (PHYP, AC5, HSP70, and AAT) from 61 individuals, as well as 11 nuclear microsatellite loci (SSR) from 102 individuals. We found relatively high genetic diversity within populations and high genetic differentiation among populations of C. panzhihuaensis, which is consistent with the patterns of other Asian inland cycads. Although no significant phylogeographical structure was detected, we found that small and unprotected populations possess higher genetic diversity and more unique haplotypes, which revises our understanding of diversity within this species and deserves due attention. Analysis of demographic dynamics suggest that human activity might be the key threat to C. panzhihuaensis. Based on the genetic characterization of C. panzhihuaensis, we propose several practical guidelines for the conservation of this species, especially for the populations with small sizes.
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Affiliation(s)
- Siyue Xiao
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, No. 132 Lanhei RD, Panlong District, Kunming, Yunnan province, 650201, China
- University of Chinese Academy of Sciences, No. 19A, Yuquan Road, Shijingshan District, Beijing, 100049, China
| | - Yunheng Ji
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, No. 132 Lanhei RD, Panlong District, Kunming, Yunnan province, 650201, China
| | - Jian Liu
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, No. 132 Lanhei RD, Panlong District, Kunming, Yunnan province, 650201, China
| | - Xun Gong
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, No. 132 Lanhei RD, Panlong District, Kunming, Yunnan province, 650201, China
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Cai C, Escalona HE, Li L, Yin Z, Huang D, Engel MS. Beetle Pollination of Cycads in the Mesozoic. Curr Biol 2018; 28:2806-2812.e1. [PMID: 30122529 DOI: 10.1016/j.cub.2018.06.036] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 06/06/2018] [Accepted: 06/18/2018] [Indexed: 11/28/2022]
Abstract
Cycads, unlike modern wind-pollinated conifers and Ginkgo, are unusual in that they are an ancient group of gymnosperms pollinated by insects [1-3]. Although it is well documented that cycads were diverse and abundant during the mid-Mesozoic, little is known about their biogeography and pollination before the rise of angiosperms. Direct fossil evidence illuminating the evolutionary history of cycads is extremely rare [4, 5]. Here we report a specialized beetle-mediated pollination mode from the mid-Cretaceous of Myanmar, wherein a new boganiid beetle, Cretoparacucujus cycadophilus, with specialized pollen-feeding adaptations in its mouthparts and legs, was associated with many pollen grains of Cycadopites. Phylogenetic analyses indicate Cretoparacucujus as a sister group to the extant Australian Paracucujus, which pollinate the cycad Macrozamia riedlei. Our discovery, along with the current disjunct distribution of related beetle-herbivore (tribe Paracucujini) and cycad-host (tribe Encephalarteae) pairs in South Africa and Australia, indicate a probable ancient origin of beetle pollination of cycads at least in the Early Jurassic, long before angiosperm dominance and the radiation of flowering-plant pollinators later in the Cretaceous.
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Affiliation(s)
- Chenyang Cai
- CAS Key Laboratory of Economic Stratigraphy and Palaeogeography, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China; Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, China; School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK.
| | - Hermes E Escalona
- Centre for Molecular Biodiversity Research (ZMB), Museum Alexander Koenig, Adenauerallee, 53113 Bonn, Germany; Australian National Insect Collection, CSIRO, G.P.O. Box 1700, Canberra, ACT 2601, Australia
| | - Liqin Li
- Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Ziwei Yin
- Department of Biology, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Diying Huang
- Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Michael S Engel
- Division of Entomology, Natural History Museum, University of Kansas, 1501 Crestline Drive, Suite 140, Lawrence, KS 66045-4415, USA; Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045, USA
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Pollination of the Australian cycad Cycas ophiolitica (Cycadaceae): the limited role of wind pollination in a cycad with beetle pollinator mutualists, and its ecological significance. JOURNAL OF TROPICAL ECOLOGY 2018. [DOI: 10.1017/s0266467418000111] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Abstract:Cycads in the Zamiaceae are well known for their host-specific insect pollination mutualisms. Pollination of Cycas in the sister family Cycadaceae is less well-documented, with beetle pollination possibly coexisting with a limited potential for wind pollination, a hypothesis we tested for C. ophiolitica in Central Queensland, Australia. Cones were associated with three species of beetle: an undescribed weevil (Curculionidae), Hapalips sp. (Erotylidae) and Ulomoides sp. (Tenebrionidae). Pollination-vector exclusion experiments compared the pollination success (quantified as % ovules pollinated per cone) of control cones against bagged or netted cones that excluded wind or insects respectively (n = 10 for all treatments). Insects do pollinate C. ophiolitica in the absence of wind, the median (first quartile-third quartile) pollination success of control plants being 83.7% (60.8–87.2%) while bagged cones, from which wind, but not insects, were excluded, pollinated at 52.9% (19.5–74.8%). For netted cones, (excluding insects but not wind), pollination fell to 12.6% (10.9–45.9%). Airborne pollen (as quantified by capture on a series of adhesive pollen traps) decreased rapidly with distance from male cones, potentially becoming ineffective for wind pollination at ~5 m. Airborne pollen load in the vicinity of female cones, and distance of females from neighbouring males, suggests wind pollination may occur sporadically, but only at high spatial densities. Although Cycas appears to be primarily insect pollinated, this limited potential for ambophily may be significant given the history of dispersal and pollinator host shifts among these cycads.
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Peris D, Pérez-de la Fuente R, Peñalver E, Delclòs X, Barrón E, Labandeira CC. False Blister Beetles and the Expansion of Gymnosperm-Insect Pollination Modes before Angiosperm Dominance. Curr Biol 2017; 27:897-904. [DOI: 10.1016/j.cub.2017.02.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 01/25/2017] [Accepted: 02/02/2017] [Indexed: 11/28/2022]
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Zanatta F, Patiño J, Lebeau F, Massinon M, Hylander K, de Haan M, Ballings P, Degreef J, Vanderpoorten A. Measuring spore settling velocity for an improved assessment of dispersal rates in mosses. ANNALS OF BOTANY 2016; 118:197-206. [PMID: 27296133 PMCID: PMC4970359 DOI: 10.1093/aob/mcw092] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Accepted: 03/31/2016] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND AIMS The settling velocity of diaspores is a key parameter for the measurement of dispersal ability in wind-dispersed plants and one of the most relevant parameters in explicit dispersal models, but remains largely undocumented in bryophytes. The settling velocities of moss spores were measured and it was determined whether settling velocities can be derived from spore diameter using Stokes' Law or if specific traits of spore ornamentation cause departures from theoretical expectations. METHODS A fall tower design combined with a high-speed camera was used to document spore settling velocities in nine moss species selected to cover the range of spore diameters within the group. Linear mixed effect models were employed to determine whether settling velocity can be predicted from spore diameter, taking specific variation in shape and surface roughness into account. KEY RESULTS Average settling velocity of moss spores ranged from 0·49 to 8·52 cm s(-1) There was a significant positive relationship between spore settling velocity and size, but the inclusion of variables of shape and texture of spores in the best-fit models provides evidence for their role in shaping spore settling velocities. CONCLUSIONS Settling velocities in mosses can significantly depart from expectations derived from Stokes' Law. We suggest that variation in spore shape and ornamentation affects the balance between density and drag, and results in different dispersal capacities, which may be correlated with different life-history traits or ecological requirements. Further studies on spore ultrastructure would be necessary to determine the role of complex spore ornamentation patterns in the drag-to-mass ratio and ultimately identify what is the still poorly understood function of the striking and highly variable ornamentation patterns of the perine layer on moss spores.
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Affiliation(s)
- Florian Zanatta
- Department of Conservation Biology and Evolution, Institute of Botany, University of Liège, Sart Tilman, Liège, Belgium
| | - Jairo Patiño
- Department of Conservation Biology and Evolution, Institute of Botany, University of Liège, Sart Tilman, Liège, Belgium Island Ecology and Evolution Research Group, Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), La Laguna, Tenerife, Canary Islands, Spain
| | - Frederic Lebeau
- Biosystems Engineering Department, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Mathieu Massinon
- Biosystems Engineering Department, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Kristofer Hylander
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
| | - Myriam de Haan
- Department of Cryptogamy, National Botanic Garden of Belgium, Meise, Belgium
| | - Petra Ballings
- Department of Cryptogamy, National Botanic Garden of Belgium, Meise, Belgium
| | - Jerôme Degreef
- Department of Cryptogamy, National Botanic Garden of Belgium, Meise, Belgium
| | - Alain Vanderpoorten
- Department of Conservation Biology and Evolution, Institute of Botany, University of Liège, Sart Tilman, Liège, Belgium
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Bolinder K, Niklas KJ, Rydin C. Aerodynamics and pollen ultrastructure in Ephedra. AMERICAN JOURNAL OF BOTANY 2015; 102:457-70. [PMID: 25784479 DOI: 10.3732/ajb.1400517] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
UNLABELLED • PREMISE OF THE STUDY Pollen dispersal is affected by the terminal settling velocity (Ut) of the grains, which is determined by their size, bulk density, and by atmospheric conditions. The likelihood that wind-dispersed pollen is captured by ovulate organs is influenced by the aerodynamic environment created around and by ovulate organs. We investigated pollen ultrastructure and Ut of Ephedra foeminea (purported to be entomophilous), and simulated the capture efficiency of its ovules. Results were compared with those from previously studied anemophilous Ephedra species.• METHODS Ut was determined using stroboscopic photography of pollen in free fall. The acceleration field around an "average" ovule was calculated, and inflight behavior of pollen grains was predicted using computer simulations. Pollen morphology and ultrastructure were investigated using SEM and STEM.• KEY RESULTS Pollen wall ultrastructure was correlated with Ut in Ephedra. The relative proportion and amount of granules in the infratectum determine pollen bulk densities, and (together with overall size) determine Ut and thus dispersal capability. Computer simulations failed to reveal any functional traits favoring anemophilous pollen capture in E. foeminea.• CONCLUSION The fast Ut and dense ultrastructure of E. foeminea pollen are consistent with functional traits that distinguish entomophilous species from anemophilous species. In anemophilous Ephedra species, ovulate organs create an aerodynamic microenvironment that directs airborne pollen to the pollination drops. In E. foeminea, no such microenvironment is created. Ephedroid palynomorphs from the Cretaceous share the ultrastructural characteristics of E. foeminea, and at least some may, therefore, have been produced by insect-pollinated plants.
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Affiliation(s)
- Kristina Bolinder
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, SE-106 91, Sweden
| | - Karl J Niklas
- Section of Plant Biology, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 USA
| | - Catarina Rydin
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, SE-106 91, Sweden
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Khorsand Rosa R, Koptur S. New findings on the pollination biology of Mauritia flexuosa (Arecaceae) in Roraima, Brazil: linking dioecy, wind, and habitat. AMERICAN JOURNAL OF BOTANY 2013; 100:613-621. [PMID: 23455480 DOI: 10.3732/ajb.1200446] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
PREMISE OF THE STUDY Despite the ecological, economic, and cultural importance of the palm Mauritia flexuosa in Amazonia, knowledge of its reproductive biology is scarce. Previous observations of this species suggested beetles as the probable pollinator, but experimental work to confirm this hypothesis was lacking. • METHODS We investigated the floral biology and pollination of M. flexuosa in undisturbed forest, undisturbed savanna/forest ecotone, and fragmented savanna within plantations of the exotic tree, Acacia mangium, in northern Brazilian Amazonia. In each habitat, we examined floral biology, combined floral visitor observations with laboratory analyses, and performed anemophily and exclusion experiments. • KEY RESULTS Fruit set was significantly greater in the visitor exclusion treatment than in the wind + visitor exclusion treatment and significantly lower in the wind + visitor exclusion treatment than the open control, but there was no difference in fruit set between the visitor exclusion treatment and the control. We found no significant difference in pollen dispersal among the three habitats. The presence of A. mangium appears to have no immediate effect on pollination of M. flexuosa, although it may indirectly affect other aspects of this native's reproductive ecology. • CONCLUSIONS Floral visitors of M. flexuosa are not pollinators. This dioecious palm depends on wind as its primary pollen vector. Wind pollination is not necessarily most effective in open habitats. These findings are important because they re-evaluate traditional assumptions of wind pollination and can improve management strategies of this natural resource in the Amazon.
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Affiliation(s)
- Roxaneh Khorsand Rosa
- Department of Biological Sciences, Florida International University, Modesto Maidique Campus, Miami, FL 33199, USA.
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Abstract
Within modern gymnosperms, conifers and Ginkgo are exclusively wind pollinated whereas many gnetaleans and cycads are insect pollinated. For cycads, thrips are specialized pollinators. We report such a specialized pollination mode from Early Cretaceous amber of Spain, wherein four female thrips representing a genus and two species in the family Melanthripidae were covered by abundant Cycadopites pollen grains. These females bear unique ring setae interpreted as specialized structures for pollen grain collection, functionally equivalent to the hook-tipped sensilla and plumose setae on the bodies of bees. The most parsimonious explanation for this structure is parental food provisioning for larvae, indicating subsociality. This association provides direct evidence of specialized collection and transportation of pollen grains and likely gymnosperm pollination by 110-105 million years ago, possibly considerably earlier.
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