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Ronse A, Van de Vyver A, Vandelook F. Seed germination requirements of the rare Helosciadium repens (aka Apium repens) determine persistence of seeds in the soil seed bank. PLANT BIOLOGY (STUTTGART, GERMANY) 2024. [PMID: 38979780 DOI: 10.1111/plb.13681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Accepted: 05/24/2024] [Indexed: 07/10/2024]
Abstract
The rare and threatened Heliosciadium repens grows in moist grasslands and has a distinct life cycle. Plants reproduce both clonally, although ramets tend to be short-lived, and sexually, with seeds that can form a persistent soil seed bank. The germination requirements of H. repens were investigated, yielding important information for its habitat management and conservation. We examined the soil seed bank in three populations and carried out germination experiments and embryo growth measurements with fresh seeds in laboratory, greenhouse and outdoor conditions. We also investigated the effects of storage and burial of seeds. H. repens formed a long-term persistent (>6 years) soil seed bank with very pronounced primary dormancy, but no secondary dormancy or dormancy cycles. Seeds can germinate throughout the growing season when temperatures are sufficiently high. Embryo growth and seed germination are triggered by light and, to a lesser extent, daily temperature fluctuations. Seeds of H. repens seem to have developed a unique germination syndrome with several strategies to remain dormant in the soil until optimal conditions are present for seedling establishment and survival. Both sexual reproduction and seed bank formation are crucial for the long-term survival of the populations.
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Affiliation(s)
- A Ronse
- Meise Botanic Garden, Meise, Belgium
| | | | - F Vandelook
- Meise Botanic Garden, Meise, Belgium
- Division of Ecology, Evolution and Biodiversity Conservation, KU Leuven, Leuven, Belgium
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2
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Visscher AM, Vandelook F, Fernández-Pascual E, Pérez-Martínez LV, Ulian T, Diazgranados M, Mattana E. Low availability of functional seed trait data from the tropics could negatively affect global macroecological studies, predictive models and plant conservation. ANNALS OF BOTANY 2022; 130:773-784. [PMID: 36349952 PMCID: PMC9758304 DOI: 10.1093/aob/mcac130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 11/01/2022] [Indexed: 06/13/2023]
Abstract
BACKGROUND Plant seeds have many traits that influence ecological functions, ex situ conservation, restoration success and their sustainable use. Several seed traits are known to vary significantly between tropical and temperate regions. Here we present three additional traits for which existing data indicate differences between geographical zones. We discuss evidence for geographical bias in availability of data for these traits, as well as the negative consequences of this bias. SCOPE We reviewed the literature on seed desiccation sensitivity studies that compare predictive models to experimental data and show how a lack of data on populations and species from tropical regions could reduce the predictive power of global models. In addition, we compiled existing data on relative embryo size and post-dispersal embryo growth and found that relative embryo size was significantly larger, and embryo growth limited, in tropical species. The available data showed strong biases towards non-tropical species and certain families, indicating that these biases need to be corrected to perform truly global analyses. Furthermore, we argue that the low number of seed germination studies on tropical high-mountain species makes it difficult to compare across geographical regions and predict the effects of climate change in these highly specialized tropical ecosystems. In particular, we show that seed traits of geographically restricted páramo species have been studied less than those of more widely distributed species, with most publications unavailable in English or in the peer-reviewed literature. CONCLUSIONS The low availability of functional seed trait data from populations and species in the tropics can have negative consequences for macroecological studies, predictive models and their application to plant conservation. We propose that global analyses of seed traits with evidence for geographical variation prioritize generation of new data from tropical regions as well as multi-lingual searches of both the grey- and peer-reviewed literature in order to fill geographical and taxonomic gaps.
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Affiliation(s)
| | | | | | - Laura Victoria Pérez-Martínez
- Royal Botanic Gardens, Kew, Wakehurst, Ardingly, Haywards Heath, West Sussex, RH17 6TN, UK
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW 2753, Australia
| | - Tiziana Ulian
- Royal Botanic Gardens, Kew, Wakehurst, Ardingly, Haywards Heath, West Sussex, RH17 6TN, UK
| | - Mauricio Diazgranados
- Royal Botanic Gardens, Kew, Wakehurst, Ardingly, Haywards Heath, West Sussex, RH17 6TN, UK
| | - Efisio Mattana
- Royal Botanic Gardens, Kew, Wakehurst, Ardingly, Haywards Heath, West Sussex, RH17 6TN, UK
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3
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Blandino C, Fernández-Pascual E, Newton RJ, Pritchard HW. Regeneration from seed in herbaceous understorey of ancient woodlands of temperate Europe. ANNALS OF BOTANY 2022; 129:761-774. [PMID: 35020780 PMCID: PMC9292608 DOI: 10.1093/aob/mcac003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/07/2022] [Indexed: 05/29/2023]
Abstract
BACKGROUND AND AIMS European ancient woodlands are subject to land use change, and the distribution of herbaceous understorey species may be threatened because of their poor ability to colonize isolated forest patches. The regeneration niche can determine the species assembly of a community, and seed germination traits may be important descriptors of this niche. METHODS We analysed ecological records for 208 herbaceous species regarded as indicators of ancient woodlands in Europe and, where possible, collated data on seed germination traits, reviewed plant regeneration strategies and measured seed internal morphology traits. The relationship between plant regeneration strategies and ecological requirements was explored for 57 species using ordination and classification analysis. KEY RESULTS Three regeneration strategies were identified. Species growing in closed-canopy areas tend to have morphological seed dormancy, often requiring darkness and low temperatures for germination, and their shoots emerge in early spring, thus avoiding the competition for light from canopy species. These species are separated into two groups: autumn and late winter germinators. The third strategy is defined by open-forest plants with a preference for gaps, forest edges and riparian forests. They tend to have physiological seed dormancy and germinate in light and at higher temperatures, so their seedlings emerge in spring or summer. CONCLUSION Seed germination traits are fundamental to which species are good or poor colonizers of the temperate forest understorey and could provide a finer explanation than adult plant traits of species distribution patterns. Seed dormancy type, temperature stratification and light requirements for seed germination are important drivers of forest floor colonization patterns and should be taken in account when planning successful ecological recovery of temperate woodland understories.
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Affiliation(s)
| | - Eduardo Fernández-Pascual
- Science Directorate, Royal Botanic Gardens, Kew, Wakehurst, Ardlingly, West Sussex, UK
- IMIB – Biodiversity Research Institute, University of Oviedo, Mieres, Spain
| | - Rosemary J Newton
- Science Directorate, Royal Botanic Gardens, Kew, Wakehurst, Ardlingly, West Sussex, UK
| | - Hugh W Pritchard
- Science Directorate, Royal Botanic Gardens, Kew, Wakehurst, Ardlingly, West Sussex, UK
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Xia K, Daws MI, Peng LL. Climate drives patterns of seed traits in Quercus species across China. THE NEW PHYTOLOGIST 2022; 234:1629-1638. [PMID: 35306670 DOI: 10.1111/nph.18103] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 03/03/2022] [Indexed: 05/26/2023]
Abstract
Traits enabling seeds to survive post-dispersal desiccation and subsequently germinate are important aspects of plant regeneration for species with desiccation-sensitive seeds. However, how desiccation and germination-related traits co-vary and relate to patterns of climate variation are unknown. We investigated physiological traits related to desiccation and germination of desiccation-sensitive seeds from 19 Quercus species, which typically dominate subalpine, subtropical and temperate forests in China. The results demonstrate a strong relationship between climate and seed traits consistent with a hypothesis of minimizing seed death from desiccation. Seeds of subalpine species were most desiccation sensitive and died fastest when dried. These species avoided drought and cold by germinating rapidly. Subtropical and temperate oaks had more variable strategies to minimize the risk of mortality reflecting a continuum between traits that facilitate rapid germination (with the risk of rapid desiccation) and slow germination (and slow desiccation). Across the Quercus species, the relative level of seed desiccation sensitivity, which we predicted to be important for reducing the risk of drying related mortality, was independent of climate. For desiccation-sensitive seeds this suggests a more diverse range of strategies for minimizing desiccation risk than reported previously.
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Affiliation(s)
- Ke Xia
- School of Ecology and Environmental Sciences, Yunnan University, Kunming, 650091, Yunnan, China
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Institute of Biodiversity, Yunnan University, Kunming, 650504, Yunnan, China
| | - Matthew I Daws
- Environment Department, Alcoa of Australia Ltd, Huntly Mine, off Del Park Road, PO Box 172, Pinjarra, WA, 6208, Australia
| | - Lin-Lin Peng
- School of Ecology and Environmental Sciences, Yunnan University, Kunming, 650091, Yunnan, China
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Institute of Biodiversity, Yunnan University, Kunming, 650504, Yunnan, China
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Walker M, Pérez M, Steinbrecher T, Gawthrop F, Pavlović I, Novák O, Tarkowská D, Strnad M, Marone F, Nakabayashi K, Leubner-Metzger G. Molecular mechanisms and hormonal regulation underpinning morphological dormancy: a case study using Apium graveolens (Apiaceae). THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 108:1020-1036. [PMID: 34510583 DOI: 10.1111/tpj.15489] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 09/02/2021] [Accepted: 09/06/2021] [Indexed: 06/13/2023]
Abstract
Underdeveloped (small) embryos embedded in abundant endosperm tissue, and thus having morphological dormancy (MD) or morphophysiological dormancy (MPD), are considered to be the ancestral state in seed dormancy evolution. This trait is retained in the Apiaceae family, which provides excellent model systems for investigating the underpinning mechanisms. We investigated Apium graveolens (celery) MD by combined innovative imaging and embryo growth assays with the quantification of hormone metabolism, as well as the analysis of hormone and cell-wall related gene expression. The integrated experimental results demonstrated that embryo growth occurred inside imbibed celery fruits in association with endosperm degradation, and that a critical embryo size was required for radicle emergence. The regulation of these processes depends on gene expression leading to gibberellin and indole-3-acetic acid (IAA) production by the embryo and on crosstalk between the fruit compartments. ABA degradation associated with distinct spatiotemporal patterns in ABA sensitivity control embryo growth, endosperm breakdown and radicle emergence. This complex interaction between gibberellins, IAA and ABA metabolism, and changes in the tissue-specific sensitivities to these hormones is distinct from non-MD seeds. We conclude that the embryo growth to reach the critical size and the associated endosperm breakdown inside MD fruits constitute a unique germination programme.
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Affiliation(s)
- Matthew Walker
- Department of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
- Tozer Seeds, Tozer Seeds Ltd, Cobham, KT11 3EH, UK
| | - Marta Pérez
- Department of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
| | - Tina Steinbrecher
- Department of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
| | | | - Iva Pavlović
- Laboratory of Growth Regulators, Institute of Experimental Botany, Czech Academy of Sciences and Faculty of Science, Palacký University Olomouc, Olomouc, CZ-78371, Czech Republic
| | - Ondřej Novák
- Laboratory of Growth Regulators, Institute of Experimental Botany, Czech Academy of Sciences and Faculty of Science, Palacký University Olomouc, Olomouc, CZ-78371, Czech Republic
| | - Danuše Tarkowská
- Laboratory of Growth Regulators, Institute of Experimental Botany, Czech Academy of Sciences and Faculty of Science, Palacký University Olomouc, Olomouc, CZ-78371, Czech Republic
| | - Miroslav Strnad
- Laboratory of Growth Regulators, Institute of Experimental Botany, Czech Academy of Sciences and Faculty of Science, Palacký University Olomouc, Olomouc, CZ-78371, Czech Republic
| | - Federica Marone
- Swiss Light Source, Paul Scherrer Institute, Villigen, CH-5232, Switzerland
| | - Kazumi Nakabayashi
- Department of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
| | - Gerhard Leubner-Metzger
- Department of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
- Laboratory of Growth Regulators, Institute of Experimental Botany, Czech Academy of Sciences and Faculty of Science, Palacký University Olomouc, Olomouc, CZ-78371, Czech Republic
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Vandelook F, Newton RJ, Bobon N, Bohley K, Kadereit G. Evolution and ecology of seed internal morphology in relation to germination characteristics in Amaranthaceae. ANNALS OF BOTANY 2021; 127:799-811. [PMID: 33534902 PMCID: PMC8103812 DOI: 10.1093/aob/mcab012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 01/28/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND AND AIMS Internal seed morphological traits such as embryo characteristics and nutritive tissue can vary considerably within a plant lineage. These traits play a prominent role in germination processes and the success of seedling establishment, and are therefore under high selective pressure, especially in environments hostile to seedlings, such as arid, saline or highly dynamic habitats. We investigated the relationships of seed internal morphology and germination characteristics of 84 species of Amaranthaceae s.l., a family with numerous lineages that have adapted to stressful growing conditions. METHODS We used seed cross-sections to assess embryo type and the ratios of embryo to seed surface and radicle to cotyledon length. Furthermore, seed mass, mean time to germination, habitat preferences and further plant traits such as C3 or C4 photosynthesis and life form were compiled for each species. Data were analysed using phylogenetic comparative methods. KEY RESULTS We found embryo type (λ = 1), log seed mass (λ = 0.86) and the ratio of embryo to seed size (λ = 0.78) to be evolutionarily stable, with an annular embryo as ancestral in the family. Linked to shifts to the three derived embryos types (spiral, horseshoe-shaped and curved) is an increase in the ratio of root to cotyledon length and a reduction of nutritive tissue. We observed stabilizing selection towards seeds with relatively large embryos with longer radicles and less nutritive tissue that are able to germinate faster, especially in lineages with C4 photosynthesis and/or salt tolerance. CONCLUSIONS We conclude that the evolutionary shift of nutrient storage from perisperm to embryo provides an ecological advantage in extreme environments, because it enables faster germination and seedling establishment. Furthermore, the evolutionary shift towards a higher ratio of root to cotyledon length especially in small-seeded Amaranthaceae growing in saline habitats can provide an ecological advantage for fast seedling establishment.
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Affiliation(s)
- Filip Vandelook
- Living Collections Department, Meise Botanic Garden, Belgium, Nieuwelaan 38, 1860 Meise, Belgium
| | - Rosemary J Newton
- Conservation Science Department, Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex RH17 6TN, UK
| | - Nadine Bobon
- Lehrstuhl für Systematik, Biodiversität & Evolution, Ludwig-Maximilians-Universität München, Menzinger Strasse 67, 80638 München, Germany
| | - Katharina Bohley
- Lehrstuhl für Systematik, Biodiversität & Evolution, Ludwig-Maximilians-Universität München, Menzinger Strasse 67, 80638 München, Germany
| | - Gudrun Kadereit
- Lehrstuhl für Systematik, Biodiversität & Evolution, Ludwig-Maximilians-Universität München, Menzinger Strasse 67, 80638 München, Germany
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7
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Fernández-Pascual E, Carta A, Mondoni A, Cavieres LA, Rosbakh S, Venn S, Satyanti A, Guja L, Briceño VF, Vandelook F, Mattana E, Saatkamp A, Bu H, Sommerville K, Poschlod P, Liu K, Nicotra A, Jiménez-Alfaro B. The seed germination spectrum of alpine plants: a global meta-analysis. THE NEW PHYTOLOGIST 2021; 229:3573-3586. [PMID: 33205452 DOI: 10.1111/nph.17086] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 11/11/2020] [Indexed: 06/11/2023]
Abstract
Assumptions about the germination ecology of alpine plants are presently based on individual species and local studies. A current challenge is to synthesise, at the global level, the alpine seed ecological spectrum. We performed a meta-analysis of primary data from laboratory experiments conducted across four continents (excluding the tropics) and 661 species, to estimate the influence of six environmental cues on germination proportion, mean germination time and germination synchrony; accounting for seed morphology (mass, embryo : seed ratio) and phylogeny. Most alpine plants show physiological seed dormancy, a strong need for cold stratification, warm-cued germination and positive germination responses to light and alternating temperatures. Species restricted to the alpine belt have a higher preference for warm temperatures and a stronger response to cold stratification than species whose distribution extends also below the treeline. Seed mass, embryo size and phylogeny have strong constraining effects on germination responses to the environment. Globally, overwintering and warm temperatures are key drivers of germination in alpine habitats. The interplay between germination physiology and seed morphological traits further reflects pressures to avoid frost or drought stress. Our results indicate the convergence, at the global level, of the seed germination patterns of alpine species.
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Affiliation(s)
| | - Angelino Carta
- Dipartimento di Biologia, Botany Unit, University of Pisa, Pisa, 56126, Italy
| | - Andrea Mondoni
- Department of Earth and Environmental Sciences, University of Pavia, Pavia, 27100, Italy
| | - Lohengrin A Cavieres
- Departamento de Botánica|Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, 4070386, Chile
- Chile and Institute of Ecology and Biodiversity (IEB), Santiago, Chile
| | - Sergey Rosbakh
- Chair of Ecology and Conservation Biology, Institute of Plant Sciences, University of Regensburg, Regensburg, 93053, Germany
| | - Susanna Venn
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria, 3125, Australia
| | - Annisa Satyanti
- Division of Ecology & Evolution, Research School of Biology, The Australian National University, Canberra, ACT, 2600, Australia
| | - Lydia Guja
- Centre for Australian National Biodiversity Research, a joint venture between Parks Australia and CSIRO, Canberra, ACT, 2601, Australia
- National Seed Bank, Australian National Botanic Gardens, Canberra, ACT, 2601, Australia
| | | | | | - Efisio Mattana
- Natural Capital and Plant Health Department, Royal Botanic Gardens, Kew, Ardingly, RH17 6TN, UK
| | - Arne Saatkamp
- Aix Marseille Université, Université d'Avignon, CNRS, IRD, IMBE, Facultés St Jérôme, case 421, Marseille, 13397, France
| | - Haiyan Bu
- State Key Laboratory of Grassland Agro-Ecosystems, Lanzhou University, Lanzhou, 730000, China
| | - Karen Sommerville
- The Australian PlantBank, Australian Institute of Botanical Science, The Royal Botanic Gardens & Domain Trust, Mount Annan, NSW, 2567, Australia
| | - Peter Poschlod
- Chair of Ecology and Conservation Biology, Institute of Plant Sciences, University of Regensburg, Regensburg, 93053, Germany
| | - Kun Liu
- State Key Laboratory of Grassland Agro-Ecosystems, Lanzhou University, Lanzhou, 730000, China
| | - Adrienne Nicotra
- Division of Ecology & Evolution, Research School of Biology, The Australian National University, Canberra, ACT, 2600, Australia
| | - Borja Jiménez-Alfaro
- Research Unit of Biodiversity (CSUC/UO/PA), University of Oviedo, Mieres, 33600, Spain
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8
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Janssens SB, Couvreur TLP, Mertens A, Dauby G, Dagallier LPMJ, Vanden Abeele S, Vandelook F, Mascarello M, Beeckman H, Sosef M, Droissart V, van der Bank M, Maurin O, Hawthorne W, Marshall C, Réjou-Méchain M, Beina D, Baya F, Merckx V, Verstraete B, Hardy O. A large-scale species level dated angiosperm phylogeny for evolutionary and ecological analyses. Biodivers Data J 2020; 8:e39677. [PMID: 32015666 PMCID: PMC6987248 DOI: 10.3897/bdj.8.e39677] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 12/12/2019] [Indexed: 02/01/2023] Open
Abstract
Phylogenies are a central and indispensable tool for evolutionary and ecological research. Even though most angiosperm families are well investigated from a phylogenetic point of view, there are far less possibilities to carry out large-scale meta-analyses at order level or higher. Here, we reconstructed a large-scale dated phylogeny including nearly 1/8th of all angiosperm species, based on two plastid barcoding genes, matK (incl. trnK) and rbcL. Novel sequences were generated for several species, while the rest of the data were mined from GenBank. The resulting tree was dated using 56 angiosperm fossils as calibration points. The resulting megaphylogeny is one of the largest dated phylogenetic tree of angiosperms yet, consisting of 36,101 sampled species, representing 8,399 genera, 426 families and all orders. This novel framework will be useful for investigating different broad scale research questions in ecological and evolutionary biology.
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Affiliation(s)
- Steven B Janssens
- Botanic Garden Meise, Meise, Belgium Botanic Garden Meise Meise Belgium.,Laboratory for Plant Conservation and Population Biology, KULeuven, Leuven, Belgium Laboratory for Plant Conservation and Population Biology, KULeuven Leuven Belgium
| | - Thomas L P Couvreur
- DIADE, IRD, Univ. Montpellier, Montpellier, France DIADE, IRD, Univ. Montpellier Montpellier France
| | - Arne Mertens
- Botanic Garden Meise, Meise, Belgium Botanic Garden Meise Meise Belgium
| | - Gilles Dauby
- AMAP Lab, IRD, CIRAD, CNRS, INRA, Univ Montpellier, Montpellier, France AMAP Lab, IRD, CIRAD, CNRS, INRA, Univ Montpellier Montpellier France
| | - Leo-Paul M J Dagallier
- DIADE, IRD, Univ. Montpellier, Montpellier, France DIADE, IRD, Univ. Montpellier Montpellier France
| | | | - Filip Vandelook
- Botanic Garden Meise, Meise, Belgium Botanic Garden Meise Meise Belgium
| | | | | | - Marc Sosef
- Botanic Garden Meise, Meise, Belgium Botanic Garden Meise Meise Belgium
| | - Vincent Droissart
- AMAP Lab, IRD, CIRAD, CNRS, INRA, Univ Montpellier, Montpellier, France AMAP Lab, IRD, CIRAD, CNRS, INRA, Univ Montpellier Montpellier France
| | - Michelle van der Bank
- University of Johannesburg, Johannesburg, South Africa University of Johannesburg Johannesburg South Africa
| | - Olivier Maurin
- Royal Botanic Gardens, Kew, United Kingdom Royal Botanic Gardens Kew United Kingdom
| | - William Hawthorne
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom Department of Plant Sciences, University of Oxford Oxford United Kingdom
| | - Cicely Marshall
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom Department of Plant Sciences, University of Cambridge Cambridge United Kingdom
| | - Maxime Réjou-Méchain
- AMAP Lab, IRD, CIRAD, CNRS, INRA, Univ Montpellier, Montpellier, France AMAP Lab, IRD, CIRAD, CNRS, INRA, Univ Montpellier Montpellier France
| | - Denis Beina
- Université de Bangui - Cerphameta, Bangui, Central African Republic Université de Bangui - Cerphameta Bangui Central African Republic
| | - Fidele Baya
- Ministère des Eaux, Forêts, Chasse et Pêche, Bangui, Central African Republic Ministère des Eaux, Forêts, Chasse et Pêche Bangui Central African Republic
| | - Vincent Merckx
- Department of Evolutionary and Population Biology, University of Amsterdam, Amsterdam, Netherlands Department of Evolutionary and Population Biology, University of Amsterdam Amsterdam Netherlands.,Understanding Evolution Group, Naturalis Biodiversity Center, Leiden, Netherlands Understanding Evolution Group, Naturalis Biodiversity Center Leiden Netherlands
| | - Brecht Verstraete
- Natural History Museum, University of Oslo, Oslo, Norway Natural History Museum, University of Oslo Oslo Norway
| | - Olivier Hardy
- Universite Libre de Bruxelles, Brussels, Belgium Universite Libre de Bruxelles Brussels Belgium
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9
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Duncan C, Schultz N, Lewandrowski W, Good MK, Cook S. Lower dormancy with rapid germination is an important strategy for seeds in an arid zone with unpredictable rainfall. PLoS One 2019; 14:e0218421. [PMID: 31504045 PMCID: PMC6736279 DOI: 10.1371/journal.pone.0218421] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 08/27/2019] [Indexed: 11/24/2022] Open
Abstract
Seed germination traits are key drivers of population dynamics, yet they are under-represented in community ecology studies, which have predominately focussed on adult plant and seed morphological traits. We studied the seed traits and germination strategy of eight woody plant species to investigate regeneration strategies in the arid zone of eastern Australia. To cope with stochastic and minimal rainfall, we predict that arid seeds will either have rapid germination across a wide range of temperatures, improved germination under cooler temperatures, or dormancy and/or longevity traits to delay or stagger germination across time. To understand how temperature affects germination responses, seeds of eight keystone arid species were germinated under laboratory conditions, and under three diurnal temperatures (30/20°C, 25/15°C and 17/7°C) for 30 days. We also tested for decline in seed viability across 24 months in a dry-aging treatment (~20°C). Six of the eight arid species studied had non-dormant, rapidly germinating seeds, and only two species had physiological dormancy traits. Seed longevity differed widely between species, from one recalcitrant species surviving only months in aging (P50 = <3 months) and one serotinous species surviving for many years (P50 = 84 months). Our results highlight the importance of understanding the reproductive strategies of plant species in arid environments. Rapid germination, the dominant seed trait of species included in this study, allows arid species to capitalise on sporadic rainfall. However, some species also exhibit dormancy and delayed germination; this an alternative strategy which spreads the risk of germination failure over time.
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Affiliation(s)
- Corrine Duncan
- School of Health and Life Sciences, Federation University, Mt Helen, VIC, Australia
- * E-mail:
| | - Nick Schultz
- School of Health and Life Sciences, Federation University, Mt Helen, VIC, Australia
| | - Wolfgang Lewandrowski
- Kings Park Science, Department of Biodiversity, Conservation and Attractions, Kings Park, WA, Australia
- School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Megan K. Good
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Simon Cook
- School of Health and Life Sciences, Federation University, Mt Helen, VIC, Australia
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10
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Blandino C, Fernández‐Pascual E, Marin M, Vernet A, Pritchard HW. Seed ecology of the geophyte Conopodium majus (Apiaceae), indicator species of ancient woodland understories and oligotrophic meadows. PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:487-497. [PMID: 29972724 PMCID: PMC6492144 DOI: 10.1111/plb.12872] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 06/30/2018] [Indexed: 06/01/2023]
Abstract
Conopodium majus is a geophyte with pseudomonocotyly, distributed in Atlantic Europe. It is an indicator of two declining European habitats: ancient woodland understories and oligotrophic hay meadows. Attempts to reintroduce it by seed have been hindered by scarce seedling emergence and limited knowledge of its seed biology. Micro-CT scanning was used to assess pseudomonocotyly. Embryo growth and germination were studied in the laboratory and the field, using dissection and image analysis. The effects of temperature, light, nitrate and GA3 on germination were tested. Seed desiccation tolerance was investigated by storage at different RHs and by drying seeds at different stages of embryo growth. Seeds possess morphological but not physiological dormancy. Embryo growth and germination were promoted by temperatures between 0 and 5 °C, arrested above 10 °C, and indifferent to alternating temperatures, light, nitrate and GA3 . Pseudomonocotyly appears to result from cotyledon fusion. While seeds tolerated drying to 15% RH and storage for 1 year at 20 °C, viability was lost when storage was at 60% RH. Seeds imbibed at 5 °C for 84 days had significant internal embryo growth but were still able to tolerate drying to 15% RH. Reproduction by seed in C. majus follows a strategy shared by geophytes adapted to deciduous temperate forests. The evolution of fused cotyledons may enable the radicle and the hypocotyl to reach deeper into the soil where a tuber can develop. The embryo is capable of growth within the seed at low temperatures so that germination is timed for early spring.
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Affiliation(s)
- C. Blandino
- Comparative Plant and Fungal BiologyRoyal Botanic Gardens KewWest SussexUK
- Earth and Environmental Sciences DepartmentUniversity of PaviaPaviaItaly
| | - E. Fernández‐Pascual
- Comparative Plant and Fungal BiologyRoyal Botanic Gardens KewWest SussexUK
- Departamento de Biología de Organismos y SistemasUniversidad de OviedoOviedo/UviéuSpain
| | - M. Marin
- Earth and Environmental Sciences DepartmentUniversity of PaviaPaviaItaly
- Scotia SeedsBrechinUK
| | - A. Vernet
- Division of Cardiovascular MedicineWellcome Trust Centre For Human GeneticsRadcliffeUK
| | - H. W. Pritchard
- Comparative Plant and Fungal BiologyRoyal Botanic Gardens KewWest SussexUK
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11
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Saatkamp A, Cochrane A, Commander L, Guja LK, Jimenez-Alfaro B, Larson J, Nicotra A, Poschlod P, Silveira FAO, Cross AT, Dalziell EL, Dickie J, Erickson TE, Fidelis A, Fuchs A, Golos PJ, Hope M, Lewandrowski W, Merritt DJ, Miller BP, Miller RG, Offord CA, Ooi MKJ, Satyanti A, Sommerville KD, Tangney R, Tomlinson S, Turner S, Walck JL. A research agenda for seed-trait functional ecology. THE NEW PHYTOLOGIST 2019; 221:1764-1775. [PMID: 30269352 DOI: 10.1111/nph.15502] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 09/17/2018] [Indexed: 06/08/2023]
Abstract
Trait-based approaches have improved our understanding of plant evolution, community assembly and ecosystem functioning. A major challenge for the upcoming decades is to understand the functions and evolution of early life-history traits, across levels of organization and ecological strategies. Although a variety of seed traits are critical for dispersal, persistence, germination timing and seedling establishment, only seed mass has been considered systematically. Here we suggest broadening the range of morphological, physiological and biochemical seed traits to add new understanding on plant niches, population dynamics and community assembly. The diversity of seed traits and functions provides an important challenge that will require international collaboration in three areas of research. First, we present a conceptual framework for a seed ecological spectrum that builds upon current understanding of plant niches. We then lay the foundation for a seed-trait functional network, the establishment of which will underpin and facilitate trait-based inferences. Finally, we anticipate novel insights and challenges associated with incorporating diverse seed traits into predictive evolutionary ecology, community ecology and applied ecology. If the community invests in standardized seed-trait collection and the implementation of rigorous databases, major strides can be made at this exciting frontier of functional ecology.
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Affiliation(s)
- Arne Saatkamp
- Aix Marseille Université, Université d'Avignon, CNRS, IRD, IMBE, Facultés St Jérôme, case 421, 13397, Marseille, France
| | - Anne Cochrane
- Department of Biodiversity, Conservation and Attractions, Science and Conservation, Locked Bag 104, Bentley Delivery Centre, Bentley, WA, 6983, Australia
- Division of Ecology & Evolution, The Australian National University, 46 Sullivans Creek Road, Acton, ACT, 2601, Australia
| | - Lucy Commander
- Department of Biodiversity, Conservation and Attractions, Kings Park Science, 1 Kattidj Close, Kings Park, WA, 6005, Australia
- School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Lydia K Guja
- Centre for Australian National Biodiversity Research, CSIRO National Research Collections Australia, Clunies Ross St, Acton, ACT, 2601, Australia
- Biodiversity Science Section, Australian National Botanic Gardens, Clunies Ross St, Canberra, ACT, 2601, Australia
| | - Borja Jimenez-Alfaro
- Research Unit of Biodiversity (CSIC/UO/PA), Universidad de Oviedo, Edificio de Investigación, 33600, Mieres, Spain
| | - Julie Larson
- Department of Ecology & Evolutionary Biology, University of Colorado, Boulder, CO, 80309, USA
| | - Adrienne Nicotra
- Division of Ecology & Evolution, The Australian National University, 46 Sullivans Creek Road, Acton, ACT, 2601, Australia
| | - Peter Poschlod
- Ecology & Conservation Biology, Institute of Plant Sciences, University of Regensburg, D-93040, Regensburg, Germany
| | - Fernando A O Silveira
- Department of Botany, Federal University of Minas Gerais, Avenida Antônio Carlos, 6627, Belo Horizonte, MG, Brazil
| | - Adam T Cross
- School of Molecular and Life Sciences, Curtin University, Kent Street, Bentley, WA, 6102, Australia
| | - Emma L Dalziell
- Department of Biodiversity, Conservation and Attractions, Kings Park Science, 1 Kattidj Close, Kings Park, WA, 6005, Australia
- School of Molecular and Life Sciences, Curtin University, Kent Street, Bentley, WA, 6102, Australia
| | - John Dickie
- Royal Botanic Gardens Kew, Wakehurst Place, Ardingly, RH17 6TN, UK
| | - Todd E Erickson
- Department of Biodiversity, Conservation and Attractions, Kings Park Science, 1 Kattidj Close, Kings Park, WA, 6005, Australia
- School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Alessandra Fidelis
- Lab of Vegetation Ecology, Departamento de Botânica, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Avenida 24-A 1515, 13506-900, Rio Claro, Brazil
| | - Anne Fuchs
- Centre for Australian National Biodiversity Research, CSIRO National Research Collections Australia, Clunies Ross St, Acton, ACT, 2601, Australia
- Biodiversity Science Section, Australian National Botanic Gardens, Clunies Ross St, Canberra, ACT, 2601, Australia
| | - Peter J Golos
- Department of Biodiversity, Conservation and Attractions, Kings Park Science, 1 Kattidj Close, Kings Park, WA, 6005, Australia
- School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Michael Hope
- Centre for Australian National Biodiversity Research, CSIRO National Research Collections Australia, Clunies Ross St, Acton, ACT, 2601, Australia
- Atlas of Living Australia, CSIRO, Canberra, ACT, 2601, Australia
| | - Wolfgang Lewandrowski
- Department of Biodiversity, Conservation and Attractions, Kings Park Science, 1 Kattidj Close, Kings Park, WA, 6005, Australia
- School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - David J Merritt
- Department of Biodiversity, Conservation and Attractions, Kings Park Science, 1 Kattidj Close, Kings Park, WA, 6005, Australia
- School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Ben P Miller
- Department of Biodiversity, Conservation and Attractions, Kings Park Science, 1 Kattidj Close, Kings Park, WA, 6005, Australia
- School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Russell G Miller
- Department of Biodiversity, Conservation and Attractions, Kings Park Science, 1 Kattidj Close, Kings Park, WA, 6005, Australia
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA, 6150, Australia
| | - Catherine A Offord
- The Australian Plant Bank, Royal Botanic Gardens and Domain Trust, Mount Annan, NSW, 2567, Australia
| | - Mark K J Ooi
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Annisa Satyanti
- Division of Ecology & Evolution, The Australian National University, 46 Sullivans Creek Road, Acton, ACT, 2601, Australia
- Biodiversity Science Section, Australian National Botanic Gardens, Clunies Ross St, Canberra, ACT, 2601, Australia
- Center for Plant Conservation, Bogor Botanic Gardens, Indonesian Institute of Sciences, Jalan Ir. H. Juanda, Bogor, West Java, 16001, Indonesia
| | - Karen D Sommerville
- The Australian Plant Bank, Royal Botanic Gardens and Domain Trust, Mount Annan, NSW, 2567, Australia
| | - Ryan Tangney
- Department of Biodiversity, Conservation and Attractions, Kings Park Science, 1 Kattidj Close, Kings Park, WA, 6005, Australia
- School of Molecular and Life Sciences, Curtin University, Kent Street, Bentley, WA, 6102, Australia
| | - Sean Tomlinson
- Department of Biodiversity, Conservation and Attractions, Kings Park Science, 1 Kattidj Close, Kings Park, WA, 6005, Australia
- School of Molecular and Life Sciences, Curtin University, Kent Street, Bentley, WA, 6102, Australia
| | - Shane Turner
- Department of Biodiversity, Conservation and Attractions, Kings Park Science, 1 Kattidj Close, Kings Park, WA, 6005, Australia
- School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Jeffrey L Walck
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37130, USA
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Nadarajan J, Benson EE, Xaba P, Harding K, Lindstrom A, Donaldson J, Seal CE, Kamoga D, Agoo EMG, Li N, King E, Pritchard HW. Comparative Biology of Cycad Pollen, Seed and Tissue - A Plant Conservation Perspective. THE BOTANICAL REVIEW; INTERPRETING BOTANICAL PROGRESS 2018; 84:295-314. [PMID: 30174336 PMCID: PMC6105234 DOI: 10.1007/s12229-018-9203-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Cycads are the most endangered of plant groups based on IUCN Red List assessments; all are in Appendix I or II of CITES, about 40% are within biodiversity 'hotspots,' and the call for action to improve their protection is long-standing. We contend that progress in this direction will not be made until there is better understanding of cycad pollen, seed and tissue biology, which at the moment is limited to relatively few (<10%) species. We review what is known about germplasm (seed and pollen) storage and germination, together with recent developments in the application of contemporary technologies to tissues, such as isotype labelling, biomolecular markers and tissue culture. Whilst progress is being made, we conclude that an acceleration of comparative studies is needed to facilitate the integration of in situ and ex situ conservation programmes to better safeguard endangered cycads.
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Affiliation(s)
- J. Nadarajan
- Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex RH17 6TN UK
- Present Address: The New Zealand Institute for Plant & Food Research Ltd, Private Bag 11600, Palmerston North, 4442 New Zealand
| | - E. E. Benson
- Damar Research Scientists, Damar, Cuparmuir, Fife, KY15 5RJ UK
| | - P. Xaba
- South African National Biodiversity Institute, Kirstenbosch National Botanical Garden, Cape Town, Republic of South Africa
| | - K. Harding
- Damar Research Scientists, Damar, Cuparmuir, Fife, KY15 5RJ UK
| | - A. Lindstrom
- Nong Nooch Tropical Botanical Garden, Chonburi, 20250 Thailand
| | - J. Donaldson
- South African National Biodiversity Institute, Kirstenbosch National Botanical Garden, Cape Town, Republic of South Africa
| | - C. E. Seal
- Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex RH17 6TN UK
| | - D. Kamoga
- Joint Ethnobotanical Research Advocacy, P.O.Box 27901, Kampala, Uganda
| | | | - N. Li
- Fairy Lake Botanic Garden, Shenzhen, Guangdong People’s Republic of China
| | - E. King
- UNEP-World Conservation Monitoring Centre, Cambridge, UK
| | - H. W. Pritchard
- Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex RH17 6TN UK
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13
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Vandelook F, Janssens SB, Matthies D. Ecological niche and phylogeny explain distribution of seed mass in the central European flora. OIKOS 2018. [DOI: 10.1111/oik.05239] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Filip Vandelook
- Botanic Garden Meise; Nieuwelaan 38 BE-1860 Meise Belgium
- Plant Ecology; Dept of Biology, Univ. of Marburg; Marburg Germany
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14
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Vandelook F, Newton RJ, Carta A. Photophobia in Lilioid monocots: photoinhibition of seed germination explained by seed traits, habitat adaptation and phylogenetic inertia. ANNALS OF BOTANY 2018; 121:405-413. [PMID: 29293885 PMCID: PMC5838840 DOI: 10.1093/aob/mcx147] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 10/13/2017] [Indexed: 05/10/2023]
Abstract
Background and Aims Photoinhibition of seed germination, known to occur notably in species growing in dry and hot habitats, is considered an adaptation to avoid germination at the soil surface after unpredictable rainfall events during the dry season. Hence, the association of this ecophysiological response with plant life histories and the natural environment was investigated in Lilioid monocots, a group of plants where photoinhibition has been pre-eminently observed. Methods A data set including germination in light and darkness of about 150 monocots was compiled. Habitat preference, local climate conditions, seed traits and temperature conditions used during germination experiments were retrieved. Factors driving the evolution of photoinhibition were analysed within a phylogenetic framework. Key Results Significant phylogenetic signal was found in germination response (λ between 0.76 and 0.80) and photoinhibition (D = 0.406). Photoinhibition was mainly related to plant traits, namely seed coat colour, seed mass and plant height. A relationship with habitat light and moisture was also evident, but the association with climate as well as temperature conditions during incubation was rather poor. Conclusions Whilst photoinhibition is prevalent in open habitats, the relationship with habitat moisture conditions and hot and dry climate is weak. Indeed, photoinhibition is also commonly observed in temperate and alpine climate geophytes growing in habitats that are much less susceptible to drought. Hence, phylogenetic inertia, probably mediated by seed morphological traits such as seed coat colour, may explain why temperate climate species have retained photoinhibition inherited from their Mediterranean ancestors.
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Affiliation(s)
| | - Rosemary J Newton
- Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex, UK
| | - Angelino Carta
- Department of Biology, Unit of Botany, University of Pisa, Via Derna, Pisa, Italy
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15
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Carta A, Probert R, Moretti M, Peruzzi L, Bedini G. Seed dormancy and germination in three Crocus ser. Verni species (Iridaceae): implications for evolution of dormancy within the genus. PLANT BIOLOGY (STUTTGART, GERMANY) 2014; 16:1065-1074. [PMID: 24533601 DOI: 10.1111/plb.12168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Accepted: 01/20/2014] [Indexed: 06/03/2023]
Abstract
The aim of this work was to examine whether seed ecophysiological traits in three closely related Crocus species were associated with ecological niche differentiation and species divergence. Seeds of the temperate tetraploid cytotype of Crocus neapolitanus, the sub-Mediterranean C. etruscus and the Mediterranean C. ilvensis were placed either on agar in the laboratory under different periods of simulated seasonal conditions or in nylon mesh bags buried outdoors to examine embryo growth, radicle and shoot emergence. In agreement with the phenology observed outdoors, in the laboratory embryos required a cool temperature (ca. 10 °C) to grow to full size (embryo length:seed length, E:S ratio ca. 0.75) but only after seeds received a warm stratification; radicle emergence then followed immediately (November). Shoot emergence is a temporally separated phase (March) that was promoted by cold stratification in C. neapolitanus while in the other two species this time lag was attributed to a slow continuous developmental process. These species have similar embryo growth and radicle phenology but differ in their degree of epicotyl dormancy, which is related to the length of local winter. Conclusions from laboratory experiments that only consider root emergence could be misleading; evaluating the phenology of both root and shoot emergence should be considered in order to demonstrate ecologically meaningful differences in germination behaviour and to develop effective propagation protocols. Although these taxa resulted from recent speciation processes, the outcomes suggest an early onset of adaptation to local ecological factors and that phylogeny may represent a significant constraint in the evolution and expression of seed traits in Crocus.
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Affiliation(s)
- A Carta
- Department of Biology, Unit of Botany, University of Pisa, Pisa, Italy
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16
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Fernandes F, Carvalho JA. An historical review and new taxa in the Madeiran endemic genusMonizia(Apiaceae, Apioideae). ACTA ACUST UNITED AC 2014. [DOI: 10.1080/00837792.2014.909648] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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17
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Mattana E, Stuppy WH, Fraser R, Waller J, Pritchard HW. Dependency of seed dormancy types on embryo traits and environmental conditions in Ribes species. PLANT BIOLOGY (STUTTGART, GERMANY) 2014; 16:740-7. [PMID: 24138146 DOI: 10.1111/plb.12115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 09/11/2013] [Indexed: 05/26/2023]
Abstract
The hypothesis that seed dormancy may be dependent on environmental conditions and seed morphological traits was tested for six Ribes species, across an altitudinal gradient of 1300 m and a longitudinal separation of 120°. Embryo measurements and seed germination experiments were conducted for R. alpinum L., R. hudsonianum Richardson var. petiolare (Douglas) Jancz., R. nevadaense Kellogg, R. roezlii Regel var. cruentum (Greene) Rehder and R. speciosum Pursh, and data taken from the literature for R. multiflorum Kit. ex Schult. ssp. sandalioticum Arrigoni. Germination was compared with seed viability to reveal proportional seed dormancy, which was then correlated to seed/embryo morphological traits and these traits related to the seed provenance environment. The embryos of all the investigated species are linear underdeveloped and all had a morphological component of seed dormancy (MD). Seeds of R. roezlii, R. hudsonianum and R. nevadaense required a temperature and/or hormone pre-treatment in order to germinate, highlighting morphophysiological seed dormancy (MPD). Seed dormancy was found to be strongly negatively correlated with embryo length, but not with embryo to seed (E:S) ratio or seed mass. Initial embryo length was positively related to mean annual temperature. Seed dormancy in the investigated Ribes species could be quantified and predicted by the interaction of embryo traits and environmental conditions. This approach may be helpful in assessing and predicting seed dormancy in the Ribes genus and in other genera and families with underdeveloped embryos.
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Affiliation(s)
- E Mattana
- Centro Conservazione Biodiversità (CCB), Dipartimento di Scienze della Vita e dell'Ambiente, Università degli Studi di Cagliari, Cagliari, Italy; Seed Conservation Department, Wellcome Trust Millennium Building, Royal Botanic Gardens, Kew, Ardingly, West Sussex, UK
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18
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Hoyle GL, Cordiner H, Good RB, Nicotra AB. Effects of reduced winter duration on seed dormancy and germination in six populations of the alpine herb Aciphyllya glacialis (Apiaceae). CONSERVATION PHYSIOLOGY 2014; 2:cou015. [PMID: 27293636 PMCID: PMC4806741 DOI: 10.1093/conphys/cou015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 03/02/2014] [Accepted: 03/27/2014] [Indexed: 05/13/2023]
Abstract
The life stages of seed germination and seedling establishment play a vital role in maintaining plant populations and determining range dynamics of species. Thus, it is not surprising that specific germination requirements and dormancy mechanisms have evolved in all major angiosperm clades. In a rapidly changing climate, we face growing pressure to manage, conserve and restore native plant species and communities. To achieve these aims, we require solid knowledge of whether and how seed germination requirements and dormancy status vary between different populations of a given species and how germination strategies may be affected by warming climatic conditions. We assessed the effect of decreasing durations of cold stratification (i.e. conditions representing a shortened winter as predicted under climate change) on germination and dormancy of the alpine herb Aciphylla glacialis. Our results confirmed previous research showing that A. glacialis seeds possess physiological dormancy that can be alleviated by cold stratification. In addition, the results demonstrated that A. glacialis seeds have underdeveloped embryos at dispersal; these grow to germinable size following 4-9 weeks at both constant 5°C and 10-5°C (day-night) temperatures. We conclude that A. glacialis exhibits morphophysiological dormancy. Furthermore, we found that the final percentage germination and dormancy status varied significantly among natural populations and that this variation did not correlate with elevation at the site of seed origin. Seeds germinated following 6-8 weeks of cold stratification, and seedlings showed no detrimental effects as a result of shorter stratification periods. Together, these results suggest that reduced duration of winter is unlikely to have direct negative impacts on germination or early seedling growth in A. glacialis. The causes and implications of the population variation in germination traits are discussed.
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Affiliation(s)
- G. L. Hoyle
- Division of Evolution, Ecology and Genetics, Research School of Biology, Australian National University, Canberra, ACT 0200, Australia
| | - H. Cordiner
- Division of Evolution, Ecology and Genetics, Research School of Biology, Australian National University, Canberra, ACT 0200, Australia
| | - R. B. Good
- Australian National Botanical Gardens, Clunies Ross Street, Acton, Canberra, ACT 2601, Australia
- Fenner School of the Environment, Australian National University, Canberra, ACT 0200, Australia
| | - A. B. Nicotra
- Division of Evolution, Ecology and Genetics, Research School of Biology, Australian National University, Canberra, ACT 0200, Australia
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