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Sajeev N, Koornneef M, Bentsink L. A commitment for life: Decades of unraveling the molecular mechanisms behind seed dormancy and germination. THE PLANT CELL 2024; 36:1358-1376. [PMID: 38215009 PMCID: PMC11062444 DOI: 10.1093/plcell/koad328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 12/19/2023] [Indexed: 01/14/2024]
Abstract
Seeds are unique time capsules that can switch between 2 complex and highly interlinked stages: seed dormancy and germination. Dormancy contributes to the survival of plants because it allows to delay germination to optimal conditions. The switch between dormancy and germination occurs in response to developmental and environmental cues. In this review we provide a comprehensive overview of studies that have helped to unravel the molecular mechanisms underlying dormancy and germination over the last decades. Genetic and physiological studies provided a strong foundation for this field of research and revealed the critical role of the plant hormones abscisic acid and gibberellins in the regulation of dormancy and germination, and later natural variation studies together with quantitative genetics identified previously unknown genetic components that control these processes. Omics technologies like transcriptome, proteome, and translatomics analysis allowed us to mechanistically dissect these processes and identify new components in the regulation of seed dormancy and germination.
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Affiliation(s)
- Nikita Sajeev
- Wageningen Seed Science Centre, Laboratory of Plant Physiology, Wageningen University, 6708PB Wageningen, the Netherlands
| | - Maarten Koornneef
- Laboratory of Genetics, Wageningen University, 6708PB Wageningen, the Netherlands
- Max Planck Institute for Plant Breeding Research, Former Department of Plant Breeding and Genetics, Koeln 50829, Germany
| | - Leónie Bentsink
- Wageningen Seed Science Centre, Laboratory of Plant Physiology, Wageningen University, 6708PB Wageningen, the Netherlands
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2
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Siegmund GF, Moeller DA, Eckhart VM, Geber MA. Bet Hedging Is Not Sufficient to Explain Germination Patterns of a Winter Annual Plant. Am Nat 2023; 202:767-784. [PMID: 38033178 DOI: 10.1086/726785] [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] [Indexed: 12/02/2023]
Abstract
AbstractBet hedging consists of life history strategies that buffer against environmental variability by trading off immediate and long-term fitness. Delayed germination in annual plants is a classic example of bet hedging and is often invoked to explain low germination fractions. We examined whether bet hedging explains low and variable germination fractions among 20 populations of the winter annual plant Clarkia xantiana ssp. xantiana that experience substantial variation in reproductive success among years. Leveraging 15 years of demographic monitoring and 3 years of field germination experiments, we assessed the fitness consequences of seed banks and compared optimal germination fractions from a density-independent bet-hedging model to observed germination fractions. We did not find consistent evidence of bet hedging or the expected trade-off between arithmetic and geometric mean fitness, although delayed germination increased long-term fitness in 7 of 20 populations. Optimal germination fractions were two to five times higher than observed germination fractions, and among-population variation in germination fractions was not correlated with risks across the life cycle. Our comprehensive test suggests that bet hedging is not sufficient to explain the observed germination patterns. Understanding variation in germination strategies will likely require integrating bet hedging with complementary forces shaping the evolution of delayed germination.
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3
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Bertuzzi T, López-Spahr D, Gómez CA, Sühring S, Malagrina G, Baskin CC, Galíndez G. Variation in Seed Dormancy of Chaco Seasonally Dry Forest Species: Effects of Seed Traits and Population Environmental Conditions. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12091790. [PMID: 37176851 PMCID: PMC10181065 DOI: 10.3390/plants12091790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 03/10/2023] [Accepted: 03/17/2023] [Indexed: 05/15/2023]
Abstract
The persistence of subtropical seasonally dry forests urgently requires the implementation of ex situ conservation and restoration programs. We studied variation in seed traits and dormancy of six native species growing in seasonally dry Chaco forests of Argentina. We documented high intra- and interspecific variability in seed traits and dormancy. Fresh seeds of Geoffroea decorticans and Parasenegalia visco (Fabaceae) were water-permeable and nondormant (ND), while those of Parkinsonia praecox and Vachellia aroma (Fabaceae) were water-impermeable and had physical dormancy (PY). Seeds of Schnopsis lorentzii (Anacardiaceae) and Sarcomphalus mistol (Rhamnaceae) were water-permeable and had physiological dormancy (PD). Mechanical and chemical scarification were the most effective methods to break PY, and dry storage for 3 months was effective in breaking PD. Seeds of large-seeded species were ND or had PD, and those of small-seeded species had PY. Species inhabiting moist habitats had ND seeds, whereas those from seasonally dry habitats had seeds with PY or PD. These results suggest that seed traits and dormancy are species-specific and that intraspecific variation in seed traits is likely associated with high phenotypic plasticity of species in response to local environmental heterogeneity. These findings should be considered at the time of implementation of conservation techniques and for seed sourcing decisions for restoration.
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Affiliation(s)
- Tania Bertuzzi
- Centro de Investigaciones y Transferencia de Catamarca (CITCA)-CONICET, Facultad de Ciencias Agrarias, Universidad Nacional de Catamarca, Catamarca 4700, Argentina
| | - Diego López-Spahr
- Facultad de Ciencias Naturales, Universidad Nacional de Salta, Salta 4400, Argentina
| | - Carlos A Gómez
- Facultad de Ciencias Naturales, Universidad Nacional de Salta, Salta 4400, Argentina
- Laboratorio de Microscopía Electrónica de Barrido (LASEM)-CCT-CONICET, Universidad Nacional de Salta, Salta 4400, Argentina
| | - Silvia Sühring
- Facultad de Ciencias Naturales, Universidad Nacional de Salta, Salta 4400, Argentina
| | - Gisela Malagrina
- Banco Base de Germoplasma, Instituto de Recursos Biológicos, CIRN-INTA, Hurlingham, Buenos Aires 1686, Argentina
| | - Carol C Baskin
- Department of Biology, University of Kentucky, Lexington, KY 40506-0225, USA
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546-0321, USA
| | - Guadalupe Galíndez
- Facultad de Ciencias Naturales, Universidad Nacional de Salta-CCT-CONICET, Salta 4400, Argentina
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4
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Glison N, Romero D, Rosso V, Guerrero JC, Speranza PR. Understanding the Geographic Patterns of Closely-Related Species of Paspalum (Poaceae) Using Distribution Modelling and Seed Germination Traits. PLANTS (BASEL, SWITZERLAND) 2023; 12:1342. [PMID: 36987030 PMCID: PMC10052821 DOI: 10.3390/plants12061342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/09/2023] [Accepted: 02/21/2023] [Indexed: 06/19/2023]
Abstract
The sexual species of the Dilatata complex (Paspalum dasypleurum, P. flavescens, P. plurinerve, P. vacarianum, and P. urvillei) are closely related phylogenetically and show allopatric distributions, except P. urvillei. These species show microhabitat similarities and differences in germination traits. We integrated species distribution models (SDMs) and seed germination assays to determine whether germination divergences explain their biogeographic pattern. We trained SDMs in South America using species' presence-absence data and environmental variables. Additionally, populations sampled from highly favourable areas in the SDMs of these species were grown together, and their seeds germinated at different temperatures and dormancy-breaking conditions. Differences among species in seed dormancy and germination niche breadth were tested, and linear regressions between seed dormancy and climatic variables were explored. SDMs correctly classified both the observed presences and absences. Spatial factors and anthropogenic activities were the main factors explaining these distributions. Both SDMs and germination analyses confirmed that the niche of P. urvillei was broader than the other species which showed restricted distributions, narrower germination niches, and high correlations between seed dormancy and precipitation regimes. Both approaches provided evidence about the generalist-specialist status of each species. Divergences in seed dormancy between the specialist species could explain these allopatric distributions.
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Affiliation(s)
- Nicolás Glison
- Departamento de Biología Vegetal, Facultad de Agronomía, Universidad de la República, Avenida Eugenio Garzón 780, Montevideo 12900, Uruguay
| | - David Romero
- Laboratorio de Desarrollo Sustentable y Gestión Ambiental del Territorio, Instituto de Ecología y Ciencias Ambientales, Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo 11400, Uruguay
- Grupo Biogeografía, Diversidad & Conservación, Departamento Biología Animal, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - Virginia Rosso
- Cátedra de Botánica Sistemática, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, Buenos Aires C1417DSE, Argentina
| | - José Carlos Guerrero
- Laboratorio de Desarrollo Sustentable y Gestión Ambiental del Territorio, Instituto de Ecología y Ciencias Ambientales, Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo 11400, Uruguay
| | - Pablo Rafael Speranza
- Departamento de Biología Vegetal, Facultad de Agronomía, Universidad de la República, Avenida Eugenio Garzón 780, Montevideo 12900, Uruguay
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Naze M, Riviere JNE, Chiroleu F, Franck A, Fock-Bastide I. Seed germination of five species from the subalpine shrubland of a mountainous oceanic island with high conservation value (Reunion Island). Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2022.e02269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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6
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Zhang Y, Liu Y, Sun L, Baskin CC, Baskin JM, Cao M, Yang J. Seed dormancy in space and time: global distribution, paleoclimatic and present climatic drivers, and evolutionary adaptations. THE NEW PHYTOLOGIST 2022; 234:1770-1781. [PMID: 35292965 DOI: 10.1111/nph.18099] [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: 12/05/2021] [Accepted: 03/02/2022] [Indexed: 06/14/2023]
Abstract
Seed dormancy is an important life history state that increases survival and fitness of seed plants, and thus it has attracted much attention. However, global biogeography, effects of paleoenvironment, evolutionary roles of dormancy transitions, and differences in adaptations of seed dormancy between life-forms are poorly understood. We compiled global distribution records for seed dormancy of 12 743 species and their phylogeny to explore the biogeographic patterns, environmental drivers, and evolutionary transitions between seed dormancy and nondormancy. Biogeographic patterns reveal a low proportion of dormancy in tropical rainforest regions and arctic regions and a high proportion of dormancy in remaining tropical, subtropical, and temperate regions for all species and woody species. Herbaceous plants show a greater proportion of dormancy in most global regions except arctic regions. Seasonal environments have a consistent positive influence on the dormancy pattern for both life-forms, but precipitation and temperature were important driving factors for woody and herbaceous plants, respectively. Seed dormancy was the dominating state during the evolutionary history of seed plants, and dormancy transitions had a significant relationship with paleotemperatures. Dormancy and nondormancy transitions in response to fluctuating environments during long-term evolutionary history may have played important roles in the diversification of seed plants. Our results add to the current knowledge about seed dormancy from macro-adaptive perspectives and the potential adaptive mechanisms of seed plants.
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Affiliation(s)
- Yazhou Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Yuan Liu
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lu Sun
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Carol C Baskin
- Department of Biology, University of Kentucky, Lexington, KY, 40506, USA
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, 40546, USA
| | - Jerry M Baskin
- Department of Biology, University of Kentucky, Lexington, KY, 40506, USA
| | - Min Cao
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Jie Yang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
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7
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Zacchello G, Bomers S, Böhme C, Postma FM, Ågren J. Seed dormancy varies widely among
Arabidopsis thaliana
populations both between and within Fennoscandia and Italy. Ecol Evol 2022; 12:e8670. [PMID: 35261752 PMCID: PMC8888264 DOI: 10.1002/ece3.8670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 09/27/2021] [Accepted: 11/05/2021] [Indexed: 11/10/2022] Open
Abstract
The timing of germination is a key life‐history trait in plants, which is strongly affected by the strength of seed dormancy. Continental‐wide genetic variation in seed dormancy has been related to differences in climate and the timing of conditions suitable for seedling establishment. However, for predictions of adaptive potential and consequences of climatic change, information is needed regarding the extent to which seed dormancy varies within climatic regions and the factors driving such variation. We quantified dormancy of seeds produced by 17 Italian and 28 Fennoscandian populations of Arabidopsis thaliana when grown in the greenhouse and at two field sites in Italy and Sweden. To identify possible drivers of among‐population variation in seed dormancy, we examined the relationship between seed dormancy and climate at the site of population origin, and between seed dormancy and flowering time. Seed dormancy was on average stronger in the Italian compared to the Fennoscandian populations, but also varied widely within both regions. Estimates of seed dormancy in the three maternal environments were positively correlated. Among Fennoscandian populations, seed dormancy tended to increase with increasing summer temperature and decreasing precipitation at the site of population origin. In the smaller sample of Italian populations, no significant association was detected between mean seed dormancy and climate at the site of origin. The correlation between population mean seed dormancy and flowering time was weak and not statistically significant within regions. The correlation between seed dormancy and climatic factors in Fennoscandia suggests that at least some of the among‐population variation is adaptive and that climate change will affect selection on this trait. The weak correlation between population mean seed dormancy and flowering time indicates that the two traits can evolve independently.
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Affiliation(s)
- Giulia Zacchello
- Plant Ecology and Evolution Department of Ecology and Genetics EBC Uppsala University Uppsala Sweden
| | - Svenja Bomers
- Plant Ecology and Evolution Department of Ecology and Genetics EBC Uppsala University Uppsala Sweden
- Institute for Seed and Propagating Material, Phytosanitary Service and Apiculture Austrian Agency for Health and Food Safety Vienna Austria
| | - Cecilia Böhme
- Plant Ecology and Evolution Department of Ecology and Genetics EBC Uppsala University Uppsala Sweden
| | - Froukje M. Postma
- Plant Ecology and Evolution Department of Ecology and Genetics EBC Uppsala University Uppsala Sweden
| | - Jon Ågren
- Plant Ecology and Evolution Department of Ecology and Genetics EBC Uppsala University Uppsala Sweden
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8
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Transgenerational Genetic Effects Help Explain Latitudinal Variation in Seed Mass and Germination Timing in Plantago lanceolata. PLANTS 2022; 11:plants11040522. [PMID: 35214858 PMCID: PMC8880339 DOI: 10.3390/plants11040522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 02/09/2022] [Accepted: 02/11/2022] [Indexed: 11/28/2022]
Abstract
We know little about the underlying genetic control of phenotypic patterns of seed traits across large-scale geographic and environmental gradients. Such knowledge is important for understanding the evolution of populations within species and for improving species conservation. Therefore, to test for genetic variation in Plantago lanceolata, we made reciprocal crosses between northern and southern genotypes that span the species’ range in Europe. The results provide evidence of transgenerational genetic effects on seed mass and germination timing. Northern mothers produced larger seeds with delayed germination, in contrast to southern mothers, which produced smaller seeds with accelerated germination. A maternal latitude affected both the seed coat, solely maternal tissue, and embryo/endosperm tissues. Thus, latitudinal variation in seed size and germination timing can be explained, in part, by the direct influence of maternal genotype, independent of zygotic genes that parents pass directly to the embryo and endosperm. Data suggest that researchers exploring the existence and evolution of large-scale geographic variation within species test for transgenerational genetic effects. In addition, data suggest that transgenerational control of seed traits should be considered when developing procedures designed to facilitate species conservation and restoration.
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Chano V, Domínguez-Flores T, Hidalgo-Galvez MD, Rodríguez-Calcerrada J, Pérez-Ramos IM. Epigenetic responses of hare barley (Hordeum murinum subsp. leporinum) to climate change: an experimental, trait-based approach. Heredity (Edinb) 2021; 126:748-762. [PMID: 33608652 PMCID: PMC8102545 DOI: 10.1038/s41437-021-00415-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 01/29/2021] [Accepted: 01/29/2021] [Indexed: 02/08/2023] Open
Abstract
The impact of reduced rainfall and increased temperatures forecasted by climate change models on plant communities will depend on the capacity of plant species to acclimate and adapt to new environmental conditions. The acclimation process is mainly driven by epigenetic regulation, including structural and chemical modifications on the genome that do not affect the nucleotide sequence. In plants, one of the best-known epigenetic mechanisms is cytosine-methylation. We evaluated the impact of 30% reduced rainfall (hereafter "drought" treatment; D), 3 °C increased air temperature ("warming"; W), and the combination of D and W (WD) on the phenotypic and epigenetic variability of Hordeum murinum subsp. leporinum L., a grass species of high relevance in Mediterranean agroforestry systems. A full factorial experiment was set up in a savannah-like ecosystem located in southwestern Spain. H. murinum exhibited a large phenotypic plasticity in response to climatic conditions. Plants subjected to warmer conditions (i.e., W and WD treatments) flowered earlier, and those subjected to combined stress (WD) showed a higher investment in leaf area per unit of leaf mass (i.e., higher SLA) and produced heavier seeds. Our results also indicated that both the level and patterns of methylation varied substantially with the climatic treatments, with the combination of D and W inducing a clearly different epigenetic response compared to that promoted by D and W separately. The main conclusion achieved in this work suggests a potential role of epigenetic regulation of gene expression for the maintenance of homoeostasis and functional stability under future climate change scenarios.
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Affiliation(s)
- Víctor Chano
- grid.4711.30000 0001 2183 4846Research Group “Sistemas Forestales Mediterráneos”, Instituto de Recursos Naturales y Agrobiología de Sevilla. Dpto, Biogeoquímica, Ecología Vegetal y Microbiana, Consejo Superior de Investigaciones Científicas, Av. Reina Mercedes 10, 41012 Sevilla, Spain ,grid.5690.a0000 0001 2151 2978Research Group “Sistemas Naturales e Historia Forestal”, ETSI Montes, Forestal y del Medio Natural. Dpto, Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain ,grid.7450.60000 0001 2364 4210Present Address: Department of Forest Genetics and Forest Tree Breeding, University of Göttingen, Büsgenweg 2, 37077 Göttingen, Germany
| | - Tania Domínguez-Flores
- grid.5690.a0000 0001 2151 2978Research Group “Sistemas Naturales e Historia Forestal”, ETSI Montes, Forestal y del Medio Natural. Dpto, Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Maria Dolores Hidalgo-Galvez
- grid.4711.30000 0001 2183 4846Research Group “Sistemas Forestales Mediterráneos”, Instituto de Recursos Naturales y Agrobiología de Sevilla. Dpto, Biogeoquímica, Ecología Vegetal y Microbiana, Consejo Superior de Investigaciones Científicas, Av. Reina Mercedes 10, 41012 Sevilla, Spain
| | - Jesús Rodríguez-Calcerrada
- grid.5690.a0000 0001 2151 2978Research Group “Sistemas Naturales e Historia Forestal”, ETSI Montes, Forestal y del Medio Natural. Dpto, Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Ignacio Manuel Pérez-Ramos
- grid.4711.30000 0001 2183 4846Research Group “Sistemas Forestales Mediterráneos”, Instituto de Recursos Naturales y Agrobiología de Sevilla. Dpto, Biogeoquímica, Ecología Vegetal y Microbiana, Consejo Superior de Investigaciones Científicas, Av. Reina Mercedes 10, 41012 Sevilla, Spain
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10
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Waterton J, Mazer SJ, Meyer JR, Cleland EE. Trade-off drives Pareto optimality of within- and among-year emergence timing in response to increasing aridity. Evol Appl 2021; 14:658-673. [PMID: 33767742 PMCID: PMC7980269 DOI: 10.1111/eva.13145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 08/20/2020] [Accepted: 09/22/2020] [Indexed: 11/30/2022] Open
Abstract
Adaptation to current and future climates can be constrained by trade-offs between fitness-related traits. Early seedling emergence often enhances plant fitness in seasonal environments, but if earlier emergence in response to seasonal cues is genetically correlated with lower potential to spread emergence among years (i.e., bet-hedging), then this functional trade-off could constrain adaptive evolution. Consequently, selection favoring both earlier within-year emergence and greater spread of emergence among years-as is expected in more arid environments-may constrain adaptive responses to trait value combinations at which a performance gain in either function (i.e., evolving earlier within- or greater among-year emergence) generates a performance loss in the other. All such trait value combinations that cannot be improved for both functions simultaneously are described as Pareto optimal and together constitute the Pareto front. To investigate how this potential emergence timing trade-off might constrain adaptation to increasing aridity, we sourced seeds of two grasses, Stipa pulchra and Bromus diandrus, from multiple maternal lines within populations across an aridity gradient in California and examined their performance in a greenhouse experiment. We monitored emergence and assayed ungerminated seeds for viability to determine seed persistence, a metric of potential among-year emergence spread. In both species, maternal lines with larger fractions of persistent seeds emerged later, indicating a trade-off between within-year emergence speed and potential among-year emergence spread. In both species, populations on the Pareto front for both earlier emergence and larger seed persistence fraction occupied significantly more arid sites than populations off the Pareto front, consistent with the hypothesis that more arid sites impose the strongest selection for earlier within-year emergence and greater among-year emergence spread. Our results provide an example of how evaluating genetically based correlations within populations and applying Pareto optimality among populations can be used to detect evolutionary constraints and adaptation across environmental gradients.
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Affiliation(s)
- Joseph Waterton
- Ecology, Behavior & Evolution SectionUniversity of California San DiegoLa JollaCAUSA
| | - Susan J. Mazer
- Department of Ecology, Evolution and Marine BiologyUniversity of California Santa BarbaraSanta BarbaraCAUSA
| | - Justin R. Meyer
- Ecology, Behavior & Evolution SectionUniversity of California San DiegoLa JollaCAUSA
| | - Elsa E. Cleland
- Ecology, Behavior & Evolution SectionUniversity of California San DiegoLa JollaCAUSA
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11
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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: 12] [Impact Index Per Article: 4.0] [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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12
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Klupczyńska EA, Pawłowski TA. Regulation of Seed Dormancy and Germination Mechanisms in a Changing Environment. Int J Mol Sci 2021; 22:1357. [PMID: 33572974 PMCID: PMC7866424 DOI: 10.3390/ijms22031357] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 01/10/2023] Open
Abstract
Environmental conditions are the basis of plant reproduction and are the critical factors controlling seed dormancy and germination. Global climate change is currently affecting environmental conditions and changing the reproduction of plants from seeds. Disturbances in germination will cause disturbances in the diversity of plant communities. Models developed for climate change scenarios show that some species will face a significant decrease in suitable habitat area. Dormancy is an adaptive mechanism that affects the probability of survival of a species. The ability of seeds of many plant species to survive until dormancy recedes and meet the requirements for germination is an adaptive strategy that can act as a buffer against the negative effects of environmental heterogeneity. The influence of temperature and humidity on seed dormancy status underlines the need to understand how changing environmental conditions will affect seed germination patterns. Knowledge of these processes is important for understanding plant evolution and adaptation to changes in the habitat. The network of genes controlling seed dormancy under the influence of environmental conditions is not fully characterized. Integrating research techniques from different disciplines of biology could aid understanding of the mechanisms of the processes controlling seed germination. Transcriptomics, proteomics, epigenetics, and other fields provide researchers with new opportunities to understand the many processes of plant life. This paper focuses on presenting the adaptation mechanism of seed dormancy and germination to the various environments, with emphasis on their prospective roles in adaptation to the changing climate.
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Affiliation(s)
| | - Tomasz A. Pawłowski
- Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland;
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13
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Copete E, Copete MA, Ferrandis P, Herranz JM. Seed germination in Narcissus yepesii (Amaryllidaceae): clinal variation in the morphophysiological dormancy levels. AOB PLANTS 2020; 12:plaa060. [PMID: 33408846 PMCID: PMC7774471 DOI: 10.1093/aobpla/plaa060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 11/09/2020] [Indexed: 06/12/2023]
Abstract
Seed dormancy classes determine both population and species-level processes which can be crucial in the life cycle of many plants. However, there are no studies of a dormancy cline between levels of morphophysiological dormancy (MPD). We aimed to determine the class of seed dormancy of Narcissus yepesii exhibits in order to explore links between different dormancy levels, previously characterized in two closely related phylogenetic congeners, N. alcaracensis and N. longispathus. Experiments were carried out under both near-natural temperature and controlled laboratory conditions. The parameters calculated were mean embryo length, radicle and shoot emergence percentages. The effects of different periods of storage; and different periods with or without GA3 of warm, cold or warm plus cold were analysed. The Narcissus populations from the Baetic System of mountain ranges in south-eastern Spain show clinal variation in a northeast-southwest gradient from intermediate to non-deep complex MPD, through the coexistence of intermediate and non-deep complex MPD in N. yepesii (21 % and 74 %, respectively). In addition, 54 % of stored seeds were able to show both levels of MPD. Narcissus yepesii occupies an intermediate position between N. alcaracensis and N. longispathus in the geographical distribution and in the clinal germination ranges. It strongly suggests an evolutionary gradient, which connects the intermediate complex MPD with the non-deep complex MPD in southern Iberian daffodils. This is the first study showing a gradient in the evolution between levels of MPD. Our results demonstrate a cline in these levels in response to both an environmental gradient and genetic differences.
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Affiliation(s)
- Elena Copete
- E.T.S.I.A.M. Department of Plant Production and Agricultural Technology, University of Castilla-La Mancha, Albacete, Spain
- Institute of Botany, University of Castilla-La Mancha, Albacete, Spain
| | - Miguel A Copete
- E.T.S.I.A.M. Department of Plant Production and Agricultural Technology, University of Castilla-La Mancha, Albacete, Spain
- Institute of Botany, University of Castilla-La Mancha, Albacete, Spain
| | - Pablo Ferrandis
- E.T.S.I.A.M. Department of Plant Production and Agricultural Technology, University of Castilla-La Mancha, Albacete, Spain
- Institute of Botany, University of Castilla-La Mancha, Albacete, Spain
| | - José M Herranz
- E.T.S.I.A.M. Department of Plant Production and Agricultural Technology, University of Castilla-La Mancha, Albacete, Spain
- Institute of Botany, University of Castilla-La Mancha, Albacete, Spain
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14
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Finch J, Walck JL, Hidayati SN, Kramer AT, Lason V, Havens K. Germination niche breadth varies inconsistently among three Asclepias congeners along a latitudinal gradient. PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:425-438. [PMID: 29779252 DOI: 10.1111/plb.12843] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 05/14/2018] [Indexed: 06/08/2023]
Abstract
Species responses to climate change will be primarily driven by their environmental tolerance range, or niche breadth, with the expectation that broad niches will increase resilience. Niche breadth is expected to be larger in more heterogeneous environments and moderated by life history. Niche breadth also varies across life stages. Therefore, the life stage with the narrowest niche may serve as the best predictor of climatic vulnerability. To investigate the relationship between niche breadth, climate and life stage we identify germination niche breadth for dormant and non-dormant seeds in multiple populations of three milkweed (Asclepias) species. Complementary trials evaluated germination under conditions simulating historic and predicted future climate by varying cold-moist stratification temperature, length and incubation temperature. Germination niche breadth was derived from germination evenness across treatments (Levins Bn ), with stratified seeds considered less dormant than non-stratified seeds. Germination response varies significantly among species, populations and treatments. Cold-moist stratification ≥4 weeks (1-3 °C) followed by incubation at 25/15 °C+ achieves peak germination for most populations. Germination niche breadth significantly expands following stratification and interacts significantly with latitude of origin. Interestingly, two species display a positive relationship between niche breadth and latitude, while the third presents a concave quadratic relationship. Germination niche breadth significantly varies by species, latitude and population, suggesting an interaction between source climate, life history and site-specific factors. Results contribute to our understanding of inter- and intraspecific variation in germination, underscore the role of dormancy in germination niche breadth, and have implications for prioritising and conserving species under climate change.
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Affiliation(s)
- J Finch
- Program in Plant Biology and Conservation, Northwestern University, Evanston, IL, USA
- Deparment of Plant Science and Conservation, Chicago Botanic Garden, Glencoe, IL, USA
| | - J L Walck
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, USA
| | - S N Hidayati
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, USA
| | - A T Kramer
- Deparment of Plant Science and Conservation, Chicago Botanic Garden, Glencoe, IL, USA
| | - V Lason
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, USA
| | - K Havens
- Deparment of Plant Science and Conservation, Chicago Botanic Garden, Glencoe, IL, USA
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15
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Picciau R, Serra S, Porceddu M, Bacchetta G. Seed traits and germination behaviour of four Sardinian populations of Helichrysum microphyllum subsp. tyrrhenicum (Asteraceae) along an altitudinal gradient. PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:498-506. [PMID: 30120884 DOI: 10.1111/plb.12903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 08/14/2018] [Indexed: 06/08/2023]
Abstract
Helichrysum microphyllum subsp. tyrrhenicum (Asteraceae) is an endemic taxon of Sardinia and Corsica, where it grows at different altitudes. The objective of this study was to investigate the seed traits and germination behaviour of four Sardinian populations of this taxon located at different altitudes. Seed traits were evaluated, and germination tests were carried out by incubating seeds at a range of constant (5-30 °C) and alternating (25/10 °C) temperatures. The dry after-ripening (DAR) pre-treatment was also applied by storing seed in dry conditions for 3 months at 25 °C. Seed traits and germination behaviour data were statistically analysed to identify if there was a correlation with altitude. Differences in seed size, area and mass among populations were recorded, however, no relationship was found with altitude. High germination percentages were obtained in all populations, both in untreated and DAR seeds, and were positively affected by alternating temperatures. The final germination percentage and time required to reach 50% final germination (T50 ) showed no relationship with altitude. The differences in seed traits and germination detected among the studied populations of H. microphyllum subsp. tyrrhenicum were not correlated with altitude. This study provides new and important knowledge for this taxon. H. microphyllum subsp. tyrrhenicum is characterised by high germination percentages and low T50 values and does not seem to require any dormancy-breaking treatment. This species represents a high-potential native plant species that should be considered within environmental management plans.
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Affiliation(s)
- R Picciau
- Centre for the Conservation of Biodiversity (CCB), Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
- Sardinian Germplasm Bank (BG-SAR), Hortus Botanicus Karalitanus (HBK), University of Cagliari, Cagliari, Italy
| | - S Serra
- Centre for the Conservation of Biodiversity (CCB), Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
- Sardinian Germplasm Bank (BG-SAR), Hortus Botanicus Karalitanus (HBK), University of Cagliari, Cagliari, Italy
| | - M Porceddu
- Centre for the Conservation of Biodiversity (CCB), Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
- Sardinian Germplasm Bank (BG-SAR), Hortus Botanicus Karalitanus (HBK), University of Cagliari, Cagliari, Italy
| | - G Bacchetta
- Centre for the Conservation of Biodiversity (CCB), Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
- Sardinian Germplasm Bank (BG-SAR), Hortus Botanicus Karalitanus (HBK), University of Cagliari, Cagliari, Italy
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16
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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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17
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Temperature variability drives within-species variation in germination strategy and establishment characteristics of an alpine herb. Oecologia 2019; 189:407-419. [PMID: 30604086 DOI: 10.1007/s00442-018-04328-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 12/19/2018] [Indexed: 01/19/2023]
Abstract
Plant establishment and subsequent persistence are strongly influenced by germination strategy, especially in temporally and spatially heterogeneous environments. Germination strategy determines the plant's ability to synchronise germination timing and seedling emergence to a favourable growing season and thus variation in germination strategy within species may be key to persistence under more extreme and variable future climates. However, the determinants of variation in germination strategy are not well resolved. To understand the variation of germination strategy and the climate drivers, we assessed seed traits, germination patterns, and seedling establishment traits of Oreomyrrhis eriopoda from 29 populations across its range. Germination patterns were then analysed against climate data to determine the strongest climate correlates influencing the germination strategy. Oreomyrrhis eriopoda exhibits a striking range of germination strategies among populations: varying from immediate to staggered, postponed, and postponed-deep. Seeds from regions with lower temperature variability were more likely to exhibit an immediate germination strategy; however, those patterns depended on the timescale of climatic assessment. In addition, we show that these strategy differences extend to seedling establishment traits: autumn seedlings (from populations with an immediate or staggered germination strategy) exhibited a higher leaf production rate than spring seedlings (of staggered or postponed strategy). Our results demonstrate not only substantial within-species variation in germination strategy across the species distribution range, but also that this variation correlates with environmental drivers. Given that these differences also extend to establishment traits, they may reflect a critical mechanism for persistence in changing climate.
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Wadgymar SM, Mactavish RM, Anderson JT. Transgenerational and Within-Generation Plasticity in Response to Climate Change: Insights from a Manipulative Field Experiment across an Elevational Gradient. Am Nat 2018; 192:698-714. [DOI: 10.1086/700097] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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19
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Fernández-Pascual E, Mattana E, Pritchard HW. Seeds of future past: climate change and the thermal memory of plant reproductive traits. Biol Rev Camb Philos Soc 2018; 94:439-456. [PMID: 30188004 DOI: 10.1111/brv.12461] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 07/30/2018] [Accepted: 08/02/2018] [Indexed: 01/21/2023]
Abstract
Plant persistence and migration in face of climate change depends on successful reproduction by seed, a central aspect of plant life that drives population dynamics, community assembly and species distributions. Plant reproduction by seed is a chain of physiological processes, the rates of which are a function of temperature, and can be modelled using thermal time models. Importantly, while seed reproduction responds to its instantaneous thermal environment, there is also evidence of phenotypic plasticity in response to the thermal history experienced by the plant's recent ancestors, by the reproducing plant since seedling establishment, and by its seeds both before and after their release. This phenotypic plasticity enables a thermal memory of plant reproduction, which allows individuals to acclimatise to their surroundings. This review synthesises current knowledge on the thermal memory of plant reproduction by seed, and highlights its importance for modelling approaches based on physiological thermal time. We performed a comprehensive search in the Web of Science and analysed 533 relevant articles, of which 81 provided material for a meta-analysis of thermal memory in reproductive functional traits based on the effect size Zr. The articles encompassed the topics of seed development, seed yield (mass and number), seed dormancy (physiological, morphological and physical), germination, and seedling establishment. The results of the meta-analysis provide evidence for a thermal memory of seed yield, physiological dormancy and germination. Seed mass and physiological dormancy appear to be the central hubs of this memory. We argue for integrating thermal memory into a predictive framework based on physiological time modelling. This will provide a quantitative assessment of plant reproduction, a complex system that integrates past and present thermal inputs to achieve successful reproduction in changing environments. The effects of a warming environment on plant reproduction cannot be reduced to a qualitative interpretation of absolute positives and negatives. Rather, these effects need to be understood in terms of changing rates and thresholds for the physiological process that underlie reproduction by seed.
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Affiliation(s)
- Eduardo Fernández-Pascual
- Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew; Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, U.K.,Departamento de Biología de Organismos y Sistemas, Universidad de Oviedo; C/ Catedrático Rodrigo Uría, 33006, Oviedo/Uviéu, Spain
| | - Efisio Mattana
- Natural Capital and Plant Health, Royal Botanic Gardens, Kew; Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, U.K
| | - Hugh W Pritchard
- Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew; Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, U.K
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20
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Seglias AE, Williams E, Bilge A, Kramer AT. Phylogeny and source climate impact seed dormancy and germination of restoration-relevant forb species. PLoS One 2018; 13:e0191931. [PMID: 29401470 PMCID: PMC5798788 DOI: 10.1371/journal.pone.0191931] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 01/15/2018] [Indexed: 11/19/2022] Open
Abstract
For many species and seed sources used in restoration activities, specific seed germination requirements are often unknown. Because seed dormancy and germination traits can be constrained by phylogenetic history, related species are often assumed to have similar traits. However, significant variation in these traits is also present within species as a result of adaptation to local climatic conditions. A growing number of studies have attempted to disentangle how phylogeny and climate influence seed dormancy and germination traits, but they have focused primarily on species-level effects, ignoring potential population-level variation. We examined the relationships between phylogeny, climate, and seed dormancy and germination traits for 24 populations of eight native, restoration-relevant forb species found in a wide range of climatic conditions in the Southwest United States. The seeds were exposed to eight temperature and stratification length regimes designed to mimic regional climatic conditions. Phylogenetic relatedness, overall climatic conditions, and temperature conditions at the site were all significantly correlated with final germination response, with significant among-population variation in germination response across incubation treatments for seven of our eight study species. Notably, germination during stratification was significantly predicted by precipitation seasonality and differed significantly among populations for seven species. While previous studies have not examined germination during stratification as a potential trait influencing overall germination response, our results suggest that this trait should be included in germination studies as well as seed sourcing decisions. Results of this study deepen our understanding of the relationships between source climate, species identity, and germination, leading to improved seed sourcing decisions for restorations.
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Affiliation(s)
- Alexandra E. Seglias
- Program in Plant Biology and Conservation, Northwestern University, Evanston, Illinois, United States of America
- Department of Plant Science and Conservation, Chicago Botanic Garden, Glencoe, Illinois, United States of America
- * E-mail:
| | - Evelyn Williams
- Department of Plant Science and Conservation, Chicago Botanic Garden, Glencoe, Illinois, United States of America
| | - Arman Bilge
- Department of Statistics, University of Washington, Seattle, Washington, United States of America
- Computational Biology Program, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Andrea T. Kramer
- Department of Plant Science and Conservation, Chicago Botanic Garden, Glencoe, Illinois, United States of America
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21
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Giménez-Benavides L, Escudero A, García-Camacho R, García-Fernández A, Iriondo JM, Lara-Romero C, Morente-López J. How does climate change affect regeneration of Mediterranean high-mountain plants? An integration and synthesis of current knowledge. PLANT BIOLOGY (STUTTGART, GERMANY) 2018; 20 Suppl 1:50-62. [PMID: 28985449 DOI: 10.1111/plb.12643] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 09/30/2017] [Indexed: 05/25/2023]
Abstract
Mediterranean mountains are extraordinarily diverse and hold a high proportion of endemic plants, but they are particularly vulnerable to climate change, and most species distribution models project drastic changes in community composition. Retrospective studies and long-term monitoring also highlight that Mediterranean high-mountain plants are suffering severe range contractions. The aim of this work is to review the current knowledge of climate change impacts on the process of plant regeneration by seed in Mediterranean high-mountain plants, by combining available information from observational and experimental studies. We also discuss some processes that may provide resilience against changing environmental conditions and suggest some research priorities for the future. With some exceptions, there is still little evidence of the direct effects of climate change on pollination and reproductive success of Mediterranean high-mountain plants, and most works are observational and/or centred only in the post-dispersal stages (germination and establishment). The great majority of studies agree that the characteristic summer drought and the extreme heatwaves, which are projected to be more intense in the future, are the most limiting factors for the regeneration process. However, there is an urgent need for studies combining elevational gradient approaches with experimental manipulations of temperature and drought to confirm the magnitude and variability of species' responses. There is also limited knowledge about the ability of Mediterranean high-mountain plants to cope with climate change through phenotypic plasticity and local adaptation processes. This could be achieved by performing common garden and reciprocal translocation experiments with species differing in life history traits.
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Affiliation(s)
- L Giménez-Benavides
- Department Biología y Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos-ESCET, C/Tulipán, Móstoles, Madrid, Spain
| | - A Escudero
- Department Biología y Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos-ESCET, C/Tulipán, Móstoles, Madrid, Spain
| | - R García-Camacho
- Department Biología y Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos-ESCET, C/Tulipán, Móstoles, Madrid, Spain
| | - A García-Fernández
- Department Biología y Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos-ESCET, C/Tulipán, Móstoles, Madrid, Spain
| | - J M Iriondo
- Department Biología y Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos-ESCET, C/Tulipán, Móstoles, Madrid, Spain
| | - C Lara-Romero
- Global Change Research Department, Mediterranean Institute of Advanced Studies (CSIC-UIB), Esporles, Mallorca, Balearic Islands, Spain
| | - J Morente-López
- Department Biología y Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos-ESCET, C/Tulipán, Móstoles, Madrid, Spain
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Ensslin A, Van de Vyver A, Vanderborght T, Godefroid S. Ex situ cultivation entails high risk of seed dormancy loss on short-lived wild plant species. J Appl Ecol 2017. [DOI: 10.1111/1365-2664.13057] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
| | | | - Thierry Vanderborght
- Botanic Garden Meise; Meise Belgium
- Fédération Wallonie-Bruxelles; Service général de l'Enseignement supérieur et de la Recherche scientifique; Brussels Belgium
| | - Sandrine Godefroid
- Botanic Garden Meise; Meise Belgium
- Fédération Wallonie-Bruxelles; Service général de l'Enseignement supérieur et de la Recherche scientifique; Brussels Belgium
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Germination Biology of Two Invasive Physalis Species and Implications for Their Management in Arid and Semi-arid Regions. Sci Rep 2017; 7:16960. [PMID: 29208989 PMCID: PMC5717255 DOI: 10.1038/s41598-017-17169-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 11/22/2017] [Indexed: 11/19/2022] Open
Abstract
Two Solanaceae invasive plant species (Physalis angulata L. and P. philadelphica Lam. var. immaculata Waterfall) infest several arable crops and natural habitats in Southeastern Anatolia region, Turkey. However, almost no information is available regarding germination biology of both species. We performed several experiments to infer the effects of environmental factors on seed germination and seedling emergence of different populations of both species collected from various locations with different elevations and habitat characteristics. Seed dormancy level of all populations was decreased with increasing age of the seeds. Seed dormancy of freshly harvested and aged seeds of all populations was effectively released by running tap water. Germination was slightly affected by photoperiods, which suggests that seeds are slightly photoblastic. All seeds germinated under wide range of temperature (15–40 °C), pH (4–10), osmotic potential (0 to −1.2 MPa) and salinity (0–400 mM sodium chloride) levels. The germination ability of both plant species under wide range of environmental conditions suggests further invasion potential towards non-infested areas in the country. Increasing seed burial depth significantly reduced the seedling emergence, and seeds buried below 4 cm of soil surface were unable to emerge. In arable lands, soil inversion to maximum depth of emergence (i.e., 6 cm) followed by conservational tillage could be utilized as a viable management option.
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Böckelmann J, Tremetsberger K, Šumberová K, Grausgruber H, Bernhardt KG. Fitness and growth of the ephemeral mudflat species Cyperus fuscus in river and anthropogenic habitats in response to fluctuating water-levels. FLORA 2017; 234:135-149. [PMID: 31719726 PMCID: PMC6850911 DOI: 10.1016/j.flora.2017.07.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Cyperus fuscus is a representative of threatened ephemeral wetland plant communities in summer-dry shoreline habitats. We compared variation and plasticity in traits related to fitness and growth of plants germinating from the soil seed bank and established plants from river and secondary anthropogenic habitats. Plants from sites at rivers, fishponds and fish storage ponds were cultivated and selfed to get homogenous seed material for a germination and an environmental manipulation experiment involving three different water regimes. Differences in traits and their plasticities were evaluated by means of linear mixed models. Cyperus fuscus followed a low-oxygen escape strategy when flooded. Seeds of plants derived from the soil seed bank germinated faster than seeds of plants derived from established plants suggesting that short-term selection of genotypes is mediated by the particular conditions on the site during germination. The experiment revealed significant differences between river and secondary habitats as well as between the soil seed bank and established plants. For example, plants from river habitats produced the highest number of culms with inflorescences. The difference was most evident under partial submergence. Plants from fish storage ponds rapidly reached the reproductive phase, but produced less culms with inflorescences. This seemingly allows them to cope with numerous and irregular disturbances and intensive substrate moisture changes. Our results suggest that populations have adapted to conditions at secondary habitats provided by fish farming during the last centuries.
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Affiliation(s)
- Jörg Böckelmann
- Institute of Botany, Department of Integrative Biology and Biodiversity Research, University of Natural Resources and Life Sciences, Vienna, Gregor Mendel-Straβe 33, A-1180 Vienna, Austria
| | - Karin Tremetsberger
- Institute of Botany, Department of Integrative Biology and Biodiversity Research, University of Natural Resources and Life Sciences, Vienna, Gregor Mendel-Straβe 33, A-1180 Vienna, Austria
| | - Kateřina Šumberová
- Department of Vegetation Ecology, Institute of Botany, The Czech Academy of Sciences, Lidická 25/27, CZ-602 00 Brno, Czech Republic
| | - Heinrich Grausgruber
- Division of Plant Breeding, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna, Konrad Lorenz-Straβe 24, A-3430 Tulln an der Donau, Austria
| | - Karl-Georg Bernhardt
- Institute of Botany, Department of Integrative Biology and Biodiversity Research, University of Natural Resources and Life Sciences, Vienna, Gregor Mendel-Straβe 33, A-1180 Vienna, Austria
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Torres-Martínez L, Weldy P, Levy M, Emery NC. Spatiotemporal heterogeneity in precipitation patterns explain population-level germination strategies in an edaphic specialist. ANNALS OF BOTANY 2017; 119:253-265. [PMID: 27551027 PMCID: PMC5321057 DOI: 10.1093/aob/mcw161] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 04/24/2016] [Accepted: 06/10/2016] [Indexed: 05/06/2023]
Abstract
BACKGROUND AND AIMS Many locally endemic species in biodiversity hotspots are restricted to edaphic conditions that are fixed in the landscape, limiting their potential to track climate change through dispersal. Instead, such species experience strong selection for germination strategies that can track suitable conditions through time. Germination strategies were compared among populations across the geographic range of a California vernal pool annual, Lasthenia fremontii Local germination strategies were tested to determine the associations with geographic variation in precipitation patterns. METHODS This study evaluated patterns of seed germination, dormancy and mortality in response to simulated variation in the timing, amount and duration of the first autumn precipitation event using seeds from six populations that span a geographic gradient in precipitation. Next, it was tested whether the germination strategies of different populations can be predicted by historical precipitation patterns that characterize each site. KEY RESULTS A significant positive relationship was observed between the historical variability in autumn precipitation and the extent of dormancy in a population. Marginal populations, with histories of the most extreme but constant autumn precipitation levels, expressed the lowest dormancy levels. Populations from sites with historically higher levels of autumn precipitation tended to germinate faster, but this tendency was not statistically significant. CONCLUSIONS Germination in L. fremontii is cued by the onset of the first rains that characterize the beginning of winter in California's Great Central Valley. However, populations differ in how fast they germinate and the fraction of seeds that remain dormant when germination cues occur. The results suggest that seed dormancy may be a key trait for populations to track increasingly drier climates predicted by climate change models. However, the low dormancy and high mortality levels observed among seeds of the southernmost, driest populations make them most vulnerable to local extinction.
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Affiliation(s)
- Lorena Torres-Martínez
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054, USA
| | - Phillip Weldy
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054, USA
| | - Morris Levy
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054, USA
| | - Nancy C Emery
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Campus Box 334, University of Colorado, Boulder, CO 80309-0334, USA
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Bernareggi G, Carbognani M, Mondoni A, Petraglia A. Seed dormancy and germination changes of snowbed species under climate warming: the role of pre- and post-dispersal temperatures. ANNALS OF BOTANY 2016; 118:529-39. [PMID: 27390354 PMCID: PMC4998984 DOI: 10.1093/aob/mcw125] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 04/24/2016] [Accepted: 05/24/2016] [Indexed: 05/28/2023]
Abstract
BACKGROUND AND AIMS Climate warming has major impacts on seed germination of several alpine species, hence on their regeneration capacity. Most studies have investigated the effects of warming after seed dispersal, and little is known about the effects a warmer parental environment may have on germination and dormancy of the seed progeny. Nevertheless, temperatures during seed development and maturation could alter the state of dormancy, affecting the timing of emergence and seedling survival. Here, the interplay between pre- and post-dispersal temperatures driving seed dormancy release and germination requirements of alpine plants were investigated. METHODS Three plant species inhabiting alpine snowbeds were exposed to an artificial warming treatment (i.e. +1·5 K) and to natural conditions in the field. Seeds produced were exposed to six different periods of cold stratification (0, 2, 4, 8, 12 and 20 weeks at 0 °C), followed by four incubation temperatures (5, 10, 15 and 20 °C) for germination testing. KEY RESULTS A warmer parental environment produced either no or a significant increase in germination, depending on the duration of cold stratification, incubation temperatures and their interaction. In contrast, the speed of germination was less sensitive to changes in the parental environment. Moreover, the effects of warming appeared to be linked to the level of (physiological) seed dormancy, with deeper dormant species showing major changes in response to incubation temperatures and less dormant species in response to cold stratification periods. CONCLUSIONS Plants developed under warmer climates will produce seeds with changed germination responses to temperature and/or cold stratification, but the extent of these changes across species could be driven by seed dormancy traits. Transgenerational plastic adjustments of seed germination and dormancy shown here may result from increased seed viability, reduced primary and secondary dormancy state, or both, and may play a crucial role in future plant adaptation to climate change.
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Affiliation(s)
- Giulietta Bernareggi
- Università di Parma, Dipartimento di Bioscienze, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Michele Carbognani
- Università di Parma, Dipartimento di Bioscienze, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Andrea Mondoni
- Università di Pavia, Dipartimento di Scienze della Terra e dell'Ambiente, Via S. Epifanio 14, 27100 Pavia, Italy
| | - Alessandro Petraglia
- Università di Parma, Dipartimento di Bioscienze, Parco Area delle Scienze 11/A, 43124 Parma, Italy
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Early life stages contribute strongly to local adaptation in Arabidopsis thaliana. Proc Natl Acad Sci U S A 2016; 113:7590-5. [PMID: 27330113 DOI: 10.1073/pnas.1606303113] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The magnitude and genetic basis of local adaptation is of fundamental interest in evolutionary biology. However, field experiments usually do not consider early life stages, and therefore may underestimate local adaptation and miss genetically based tradeoffs. We examined the contribution of differences in seedling establishment to adaptive differentiation and the genetic architecture of local adaptation using recombinant inbred lines (RIL) derived from a cross between two locally adapted populations (Italy and Sweden) of the annual plant Arabidopsis thaliana We planted freshly matured, dormant seeds (>180 000) representing >200 RILs at the native field sites of the parental genotypes, estimated the strength of selection during different life stages, mapped quantitative trait loci (QTL) for fitness and its components, and quantified selection on seed dormancy. We found that selection during the seedling establishment phase contributed strongly to the fitness advantage of the local genotype at both sites. With one exception, local alleles of the eight distinct establishment QTL were favored. The major QTL for establishment and total fitness showed evidence of a fitness tradeoff and was located in the same region as the major seed dormancy QTL and the dormancy gene DELAY OF GERMINATION 1 (DOG1). RIL seed dormancy could explain variation in seedling establishment and fitness across the life cycle. Our results demonstrate that genetically based differences in traits affecting performance during early life stages can contribute strongly to adaptive differentiation and genetic tradeoffs, and should be considered for a full understanding of the ecology and genetics of local adaptation.
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A two-year life history cycle model for autumn and spring seedling coexistence in an annual plant—An example of intraspecific niche differentiation. Ecol Modell 2016. [DOI: 10.1016/j.ecolmodel.2016.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Alba C, Moravcová L, Pyšek P. Geographic structuring and transgenerational maternal effects shape germination in native, but not introduced, populations of a widespread plant invader. AMERICAN JOURNAL OF BOTANY 2016; 103:837-844. [PMID: 27208352 DOI: 10.3732/ajb.1600099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 03/25/2016] [Indexed: 06/05/2023]
Abstract
PREMISE OF THE STUDY Germination is critical in determining species distributions and invasion dynamics. However, is it unclear how often invasive populations evolve germination characteristics different from native populations, because few studies have isolated genetic variation by using seed from garden-grown plants. Additionally, while herbivore-induced transgenerational effects are common, it is unknown whether maternal herbivory differentially shapes germination in native and introduced offspring. METHODS We explored germination in native and introduced populations of the North American invader Verbascum thapsus using seed from garden-grown maternal plants, half of which were protected from herbivores. To elucidate (1) germination niche breadth and (2) whether germination conditions affected expression of genetic structuring among populations, we germinated seed under four ecologically relevant temperature regimes. KEY RESULTS Native populations had a wide germination niche breadth, germinating as well as or better than introduced populations. At cooler temperatures, native populations exhibited a genetically based environmental cline indicative of local adaptation, with populations from warmer locales germinating better than populations from cooler locales. However, this cline was obscured when maternal plants were attacked by herbivores, revealing that local stressors can override the expression of geographic structuring. Introduced populations did not exhibit clinal variation, suggesting its disruption during the introduction process. CONCLUSIONS Native and introduced populations have evolved genetic differences in germination. The result of this difference manifests in a wider germination niche breadth in natives, suggesting that the invasive behavior of V. thapsus in North America is attributable to other factors.
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Affiliation(s)
- Christina Alba
- Department of Invasion Ecology, Institute of Botany, The Czech Academy of Sciences, CZ-252 43 Zámek 1, Průhonice, Czech Republic
| | - Lenka Moravcová
- Department of Invasion Ecology, Institute of Botany, The Czech Academy of Sciences, CZ-252 43 Zámek 1, Průhonice, Czech Republic
| | - Petr Pyšek
- Department of Invasion Ecology, Institute of Botany, The Czech Academy of Sciences, CZ-252 43 Zámek 1, Průhonice, Czech Republic Department of Ecology, Charles University in Prague, CZ-128 44 Viničná 7, Prague, Czech Republic
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Carta A, Probert R, Puglia G, Peruzzi L, Bedini G. Local climate explains degree of seed dormancy in Hypericum elodes L. (Hypericaceae). PLANT BIOLOGY (STUTTGART, GERMANY) 2016; 18 Suppl 1:76-82. [PMID: 25662792 DOI: 10.1111/plb.12310] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 02/03/2015] [Indexed: 06/04/2023]
Abstract
Seed dormancy and germination characteristics may vary within species in response to several factors. Knowledge of such variation is crucial to understand plant evolution and adaptation to environmental changes. We examined the correlation of climate and population genetic differentiation (ISSR) with primary seed dormancy and germination behaviour in populations of the Atlantic-European soft-water pool specialist Hypericum elodes. Primary dormancy was measured by analysing seed germination response of fresh seeds and after various periods of cold stratification. Laboratory germination experiments revealed that the single most important factor for promoting germination was cold stratification prior to placing at the germination temperature. However, in agreement with their weaker primary dormancy, the seeds germinated well when fresh, and the benefit of cold stratification was more relaxed for the southern populations. Seeds of all populations demonstrated a near absolute requirement for a light and alternating temperature regime in order to germinate. The promoting effect of alternating temperatures was particularly effective at warm temperatures (mean 20 °C) but not at cool temperatures. Whilst seed germination requirements were similar among populations, the degree of primary dormancy varied considerably and was not associated with population genetic differentiation. Primary dormancy degree was instead associated with local climate: higher temperature in summer and rainfall in winter predicted weak and rapid loss of dormancy. These results suggest that seed maturation environment may play a substantial role in explaining the degree of dormancy in H. elodes, highlighting that physiological dormancy can be modulated by local climate.
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Affiliation(s)
- A Carta
- Department of Biology, Unit of Botany, University of Pisa, Pisa, Italy
| | - R Probert
- Seed Conservation Department, Royal Botanic Gardens, Kew, West Sussex, UK
| | - G Puglia
- Department of Biological, Geological and Environmental Sciences, Plant Biology Section, University of Catania, Catania, Italy
| | - L Peruzzi
- Department of Biology, Unit of Botany, University of Pisa, Pisa, Italy
| | - G Bedini
- Department of Biology, Unit of Botany, University of Pisa, Pisa, Italy
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García-Fernández A, Escudero A, Lara-Romero C, Iriondo JM. Effects of the duration of cold stratification on early life stages of the Mediterranean alpine plant Silene ciliata. PLANT BIOLOGY (STUTTGART, GERMANY) 2015; 17:344-50. [PMID: 25115908 DOI: 10.1111/plb.12226] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 05/26/2014] [Indexed: 05/25/2023]
Abstract
Cold stratification provided by snow cover is essential to break seed dormancy in many alpine plant species. The forecast reduction in snow precipitation and snow cover duration in most temperate mountains as a result of global warming could threaten alpine plant populations, especially those at the edge of their species distribution, by altering the dynamics of early life stages. We simulated some effects of a reduction in the snow cover period by manipulating the duration of cold stratification in seeds of Silene ciliata, a Mediterranean alpine specialist. Seeds from three populations distributed along an altitudinal gradient were exposed to different periods of cold stratification (2, 4 and 6 months) in the laboratory and then moved to common garden conditions in a greenhouse. The duration of the cold stratification treatment and population origin significantly affected seed emergence percentage, emergence rate and seedling size, but not the number of seedling leaves. The 6-month and 4-month cold stratification treatments produced higher emergence percentages and faster emergence rates than seeds without cold stratification treatment. No significant cold stratification duration x seed population origin interactions were found, thus differential sensitivity to cold stratification along elevation is not supported.
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Affiliation(s)
- A García-Fernández
- Institut Botanic de Barcelona, IBB-CSIC-IQUB, Barcelona, Spain; Departamento de Biología y Geología, Universidad Rey Juan Carlos, Madrid, Spain
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Fernández-Pascual E, Seal CE, Pritchard HW. Simulating the germination response to diurnally alternating temperatures under climate change scenarios: comparative studies on Carex diandra seeds. ANNALS OF BOTANY 2015; 115:201-9. [PMID: 25564469 PMCID: PMC4551094 DOI: 10.1093/aob/mcu234] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 09/23/2014] [Accepted: 10/16/2014] [Indexed: 05/31/2023]
Abstract
BACKGROUND AND AIMS Environmental temperature regulates plant regeneration via seed in several superimposed ways, and this complex regulation will be disrupted by climate change. The role of diurnally alternating temperatures (ΔT) in terminating dormancy will be a major factor in this disruption, as its effects on seed germination are immediate. METHODS The effect of ΔT on seed germination was modelled using two populations of the wetland sedge Carex diandra, one from a montane site and one from a subalpine site. A cardinal-temperature model was fitted to germination results obtained from a thermal gradient plate, and the model was used to simulate changes in germination under two possible future climate scenarios (RCP2·6 and RCP8·5, for representative concentration pathways) as defined by the Intergovernmental Panel on Climate Change. KEY RESULTS Scenario RCP2·6 projected moderate increases in average temperatures and ΔT, whereas RCP8·5 projected greater warming and higher ΔT. Increasing ΔT decreased the base temperature for seed germination and the thermal time required for germination. The effect of higher ΔT together with the higher temperatures increased germination under both climate scenarios. CONCLUSIONS Carex diandra germination is highly responsive to potential changes in ΔT, and thus this study highlights the role of ΔT in seed responses to climate change. Comprehensive cardinal-temperature models, encompassing the different effects of temperature on seed germination, are needed to understand how climate change will affect plant regeneration.
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Affiliation(s)
- Eduardo Fernández-Pascual
- Jardín Botánico Atlántico, Universidad de Oviedo, Avda. del Jardín Botánico 2230, 33394 Gijón/Xixón, Spain and Seed Conservation Department, Royal Botanic Gardens, Kew, Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex RH17 6TN, UK
| | - Charlotte E Seal
- Jardín Botánico Atlántico, Universidad de Oviedo, Avda. del Jardín Botánico 2230, 33394 Gijón/Xixón, Spain and Seed Conservation Department, Royal Botanic Gardens, Kew, Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex RH17 6TN, UK
| | - Hugh W Pritchard
- Jardín Botánico Atlántico, Universidad de Oviedo, Avda. del Jardín Botánico 2230, 33394 Gijón/Xixón, Spain and Seed Conservation Department, Royal Botanic Gardens, Kew, Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex RH17 6TN, UK
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Burghardt LT, Metcalf CJE, Wilczek AM, Schmitt J, Donohue K. Modeling the influence of genetic and environmental variation on the expression of plant life cycles across landscapes. Am Nat 2014; 185:212-27. [PMID: 25616140 DOI: 10.1086/679439] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Organisms develop through multiple life stages that differ in environmental tolerances. The seasonal timing, or phenology, of life-stage transitions determines the environmental conditions to which each life stage is exposed and the length of time required to complete a generation. Both environmental and genetic factors contribute to phenological variation, yet predicting their combined effect on life cycles across a geographic range remains a challenge. We linked submodels of the plasticity of individual life stages to create an integrated model that predicts life-cycle phenology in complex environments. We parameterized the model for Arabidopsis thaliana and simulated life cycles in four locations. We compared multiple "genotypes" by varying two parameters associated with natural genetic variation in phenology: seed dormancy and floral repression. The model predicted variation in life cycles across locations that qualitatively matches observed natural phenology. Seed dormancy had larger effects on life-cycle length than floral repression, and results suggest that a genetic cline in dormancy maintains a life-cycle length of 1 year across the geographic range of this species. By integrating across life stages, this approach demonstrates how genetic variation in one transition can influence subsequent transitions and the geographic distribution of life cycles more generally.
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Affiliation(s)
- Liana T Burghardt
- Department of Biology, Duke University, Durham, North Carolina 27708
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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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White AC, Colmer TD, Cawthray GR, Hanley ME. Variable response of three Trifolium repens ecotypes to soil flooding by seawater. ANNALS OF BOTANY 2014; 114:347-55. [PMID: 24942000 PMCID: PMC4111396 DOI: 10.1093/aob/mcu118] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Accepted: 05/07/2014] [Indexed: 05/06/2023]
Abstract
BACKGROUND AND AIMS Despite concerns about the impact of rising sea levels and storm surge events on coastal ecosystems, there is remarkably little information on the response of terrestrial coastal plant species to seawater inundation. The aim of this study was to elucidate responses of a glycophyte (white clover, Trifolium repens) to short-duration soil flooding by seawater and recovery following leaching of salts. METHODS Using plants cultivated from parent ecotypes collected from a natural soil salinity gradient, the impact of short-duration seawater soil flooding (8 or 24 h) on short-term changes in leaf salt ion and organic solute concentrations was examined, together with longer term impacts on plant growth (stolon elongation) and flowering. KEY RESULTS There was substantial Cl(-) and Na(+) accumulation in leaves, especially for plants subjected to 24 h soil flooding with seawater, but no consistent variation linked to parent plant provenance. Proline and sucrose concentrations also increased in plants following seawater flooding of the soil. Plant growth and flowering were reduced by longer soil immersion times (seawater flooding followed by drainage and freshwater inputs), but plants originating from more saline soil responded less negatively than those from lower salinity soil. CONCLUSIONS The accumulation of proline and sucrose indicates a potential for solute accumulation as a response to the osmotic imbalance caused by salt ions, while variation in growth and flowering responses between ecotypes points to a natural adaptive capacity for tolerance of short-duration seawater soil flooding in T. repens. Consequently, it is suggested that selection for tolerant ecotypes is possible should the predicted increase in frequency of storm surge flooding events occur.
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Affiliation(s)
- Anissia C White
- School of Biological Sciences, University of Plymouth, Plymouth PL4 8AA, UK
| | - Timothy D Colmer
- School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, 6009, WA, Australia
| | - Greg R Cawthray
- School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, 6009, WA, Australia
| | - Mick E Hanley
- School of Biological Sciences, University of Plymouth, Plymouth PL4 8AA, UK
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Willis CG, Baskin CC, Baskin JM, Auld JR, Venable DL, Cavender-Bares J, Donohue K, Rubio de Casas R. The evolution of seed dormancy: environmental cues, evolutionary hubs, and diversification of the seed plants. THE NEW PHYTOLOGIST 2014; 203:300-309. [PMID: 24684268 DOI: 10.1111/nph.12782] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 02/26/2014] [Indexed: 05/28/2023]
Abstract
Seed dormancy, by controlling the timing of germination, can strongly affect plant survival. The kind of seed dormancy, therefore, can influence both population and species-level processes such as colonization, adaptation, speciation, and extinction. We used a dataset comprising over 14,000 taxa in 318 families across the seed plants to test hypotheses on the evolution of different kinds of seed dormancy and their association with lineage diversification. We found morphophysiological dormancy to be the most likely ancestral state of seed plants, suggesting that physiologically regulated dormancy in response to environmental cues was present at the origin of seed plants. Additionally, we found that physiological dormancy (PD), once disassociated from morphological dormancy, acted as an 'evolutionary hub' from which other dormancy classes evolved, and that it was associated with higher rates of lineage diversification via higher speciation rates. The environmental sensitivity provided by dormancy in general, and by PD in particular, appears to be a key trait in the diversification of seed plants.
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Affiliation(s)
- Charles G Willis
- Center for the Environment, Harvard University, 24 Oxford St, Cambridge, MA, 02138, USA; Department of Biology, Duke University, Box 90338, Durham, NC, 27708, USA
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Zhou Z, Bao W. Changes in seed dormancy of Rosa multibracteata Hemsl. & E. H. Wilson with increasing elevation in an arid valley in the eastern Tibetan Plateau. Ecol Res 2014. [DOI: 10.1007/s11284-014-1155-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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