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Gómez Quijano MJ, Gross BL, Etterson JR. Genetic differentiation across a steep and narrow environmental gradient: Quantitative genetic and genomic insights into Lake Superior populations of Quercus rubra. Mol Ecol 2024; 33:e17483. [PMID: 39056407 DOI: 10.1111/mec.17483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 07/05/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024]
Abstract
Adaptive differentiation of traits and underlying loci can occur at a small geographical scale if natural selection is stronger than countervailing gene flow and drift. We investigated this hypothesis using coupled quantitative genetic and genomic approaches for a wind-pollinated tree species, Quercus rubra, along the steep, narrow gradient of the Lake Superior coast that encompasses four USDA Hardiness Zones within 100 km. For the quantitative genetic component of this study, we examined phenotypic differentiation among eight populations in a common garden, measuring seed mass, germination, height, stem diameter, leaf number, specific leaf area and survival. For the genomic component, we quantified genetic differentiation for 26 populations from the same region using RAD-seq. Because hybridisation with Quercus ellipsoidalis occurs in other parts of the species' range, we included two populations of this congener for comparison. In the common garden study, we found a strong signal of population differentiation that was significantly associated with at least one climate factor for nine of 10 measured traits. In contrast, we found no evidence of genomic differentiation among populations based on FST or any other measures. However, both distance-based and genotype-environment association analyses identified loci showing the signature of selection, with one locus in common across five analyses. This locus was associated with the minimum temperature of the coldest month, a factor that defines the climate zones and was also significant in the common garden analyses. In addition, we documented introgression from Q. ellipsoidalis into Q. rubra, with rates of introgression correlated with the climate gradient. In sum, this study reveals signatures of selection at the quantitative trait and genomic level consistent with climate adaptation, a pattern that is more often documented at a much broader geographical scale, especially in long-lived wind-pollinated species.
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Affiliation(s)
- María José Gómez Quijano
- Department of Biology, Queen's University, Kingston, Ontario, Canada
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota, USA
| | - Briana L Gross
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota, USA
| | - Julie R Etterson
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota, USA
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Larios E, Ramirez-Parada TH, Mazer SJ. Heritability and variance components of seed size in wild species: influences of breeding design and the number of genotypes tested. Heredity (Edinb) 2023; 130:251-258. [PMID: 36781978 PMCID: PMC10076259 DOI: 10.1038/s41437-023-00597-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 01/25/2023] [Accepted: 02/01/2023] [Indexed: 02/15/2023] Open
Abstract
Seed size affects individual fitness in wild plant populations, but its ability to evolve may be limited by low narrow-sense heritability (h2). h2 is estimated as the proportion of total phenotypic variance (σ2P) attributable to additive genetic variance (σ2A), so low values of h2 may be due to low σ2A (potentially eroded by natural selection) or to high values of the other factors that contribute to σ2P, such as extranuclear maternal effects (m2) and environmental variance effects (e2). Here, we reviewed the published literature and performed a meta-analysis to determine whether h2 of seed size is routinely low in wild populations and, if so, which components of σ2P contribute most strongly to total phenotypic variance. We analyzed available estimates of narrow-sense heritability (h2) of seed size, as well as the variance components contributing to these parameters. Maternal and environmental components of σ2P were significantly greater than σ2A, dominance, paternal, and epistatic components. These results suggest that low h2 of seed size in wild populations (the mean value observed in this study was 0.13) is due to both high values of maternally derived and environmental (residual) σ2, and low values of σ2A in seed size. The type of breeding design used to estimate h2 and m2 also influenced their values, with studies using diallel designs generating lower variance ratios than nested and other designs. e2 was not influenced by breeding design. For some breeding designs, the number of genotypes included in a study also influenced the resulting h2 and e2 estimates, but not m2. Our data support the view that a diallel design is better suited than the alternatives for the accurate estimation of σ2A in seed size due to its factorial design and the inclusion of reciprocal crosses, which allows the independent estimation of both additive and non-additive components of variance.
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Affiliation(s)
- Eugenio Larios
- Department of Ecology Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, USA.
- Programa Educativo de Licenciado en Ecología, Universidad Estatal de Sonora, Hermosillo, Sonora, Mexico.
| | - Tadeo H Ramirez-Parada
- Department of Ecology Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Susan J Mazer
- Department of Ecology Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, USA
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Jiménez-Ramírez A, Solé-Medina A, Ramírez-Valiente JA, Robledo-Arnuncio JJ. Microgeographic variation in early fitness traits of Pinus sylvestris from contrasting soils. AMERICAN JOURNAL OF BOTANY 2023; 110:e16159. [PMID: 36943007 DOI: 10.1002/ajb2.16159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 03/01/2023] [Accepted: 03/01/2023] [Indexed: 05/11/2023]
Abstract
PREMISE The possibility of fine-scale intraspecific adaptive divergence under gene flow is established by theoretical models and has been confirmed empirically in tree populations distributed along steep altitudinal clines or across extreme edaphic discontinuities. However, the possibility of microgeographic adaptive divergence due to less severe but more frequent kinds of soil variation is unclear. METHODS In this study, we looked for evidence of local adaptation to calcareous versus siliceous soil types in two nearby Mediterranean Pinus sylvestris populations connected via pollen flow. Using a greenhouse experiment, we tested for variation in early (up to three years of age) seedling performance among open-pollinated maternal families originating from each edaphic provenance when experimentally grown on both types of natural local substrate. RESULTS Although seedlings were clearly affected by the edaphic environment, exhibiting lower and slower emergence as well as higher mortality on the calcareous than in the siliceous substrate, neither the performance on each substrate nor the plasticity among substrates varied significantly with seedling edaphic provenance. CONCLUSIONS We found no evidence of local adaptation to a non-extreme edaphic discontinuity over a small spatial scale, at least during early stages of seedling establishment. Future studies on microgeographic soil-driven adaptation should consider long-term experiments to minimize maternal effects and allow a potentially delayed expression of edaphic adaptive divergence.
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Affiliation(s)
- Azucena Jiménez-Ramírez
- Instituto de Ciencias Forestales, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (ICIFOR-INIA), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- Department of Genetics, Faculty of Biological Sciences, Complutense University of Madrid, Madrid, Spain
| | - Aida Solé-Medina
- Instituto de Ciencias Forestales, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (ICIFOR-INIA), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - José A Ramírez-Valiente
- Instituto de Ciencias Forestales, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (ICIFOR-INIA), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- Ecological and Forestry Applications Research Centre (CREAF), Cerdanyola del Vallès, Spain
| | - Juan J Robledo-Arnuncio
- Instituto de Ciencias Forestales, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (ICIFOR-INIA), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
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Ju T, Han ZT, Ruhsam M, Li JL, Tao WJ, Tso S, Miehe G, Mao KS. Reproduction and genetic diversity of Juniperus squamata along an elevational gradient in the Hengduan Mountains. PLANT DIVERSITY 2022; 44:369-376. [PMID: 35967254 PMCID: PMC9363649 DOI: 10.1016/j.pld.2021.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 12/06/2021] [Accepted: 12/06/2021] [Indexed: 06/15/2023]
Abstract
Elevation plays a crucial factor in the distribution of plants, as environmental conditions become increasingly harsh at higher elevations. Previous studies have mainly focused on the effects of large-scale elevational gradients on plants, with little attention on the impact of smaller-scale gradients. In this study we used 14 microsatellite loci to survey the genetic structure of 332 Juniperus squamata plants along elevation gradient from two sites in the Hengduan Mountains. We found that the genetic structure (single, clonal, mosaic) of J. squamata shrubs is affected by differences in elevational gradients of only 150 m. Shrubs in the mid-elevation plots rarely have a clonal or mosaic structure compared to shrubs in lower- or higher-elevation plots. Human activity can significantly affect genetic structure, as well as reproductive strategy and genetic diversity. Sub-populations at mid-elevations had the highest yield of seed cones, lower levels of asexual reproduction and higher levels of genetic diversity. This may be due to the trade-off between elevational stress and anthropogenic disturbance at mid-elevation since there is greater elevational stress at higher-elevations and greater intensity of anthropogenic disturbance at lower-elevations. Our findings provide new insights into the finer scale genetic structure of alpine shrubs, which may improve the conservation and management of shrublands, a major vegetation type on the Hengduan Mountains and the Qinghai-Tibet Plateau.
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Affiliation(s)
- Tsam Ju
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Zhi-Tong Han
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Markus Ruhsam
- Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh EH3 5LR, UK
| | - Jia-Liang Li
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Wen-Jing Tao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Sonam Tso
- College of Science, Tibet University, Lhasa, Tibet 850000, China
| | - Georg Miehe
- Department of Geography, Philipps-Universität Marburg, Deutschhausstraße 10, Marburg 35032, Hessen, Germany
| | - Kang-Shan Mao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan 610065, China
- College of Science, Tibet University, Lhasa, Tibet 850000, China
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Callejas‐Díaz M, Chambel MR, San‐Martín‐Lorén J, Gea‐Izquierdo G, Santos‐Del‐Blanco L, Postma E, Climent JM. The role of maternal age, growth, and environment in shaping offspring performance in an aerial conifer seed bank. AMERICAN JOURNAL OF BOTANY 2022; 109:366-376. [PMID: 34973037 PMCID: PMC9790720 DOI: 10.1002/ajb2.1811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 12/10/2021] [Accepted: 12/14/2021] [Indexed: 05/09/2023]
Abstract
PREMISE Maternal effects have been demonstrated to affect offspring performance in many organisms, and in plants, seeds are important mediators of these effects. Some woody plant species maintain long-lasting canopy seed banks as an adaptation to wildfires. Importantly, these seeds stored in serotinous cones are produced by the mother plant under varying ontogenetic and physiological conditions. METHODS We sampled the canopy seed bank of a highly serotinous population of Pinus pinaster to test whether maternal age and growth and the environmental conditions during each crop year affected seed mass and ultimately germination and early survival. After determining retrospectively the year of each seed cohort, we followed germination and early survival in a semi-natural common garden. RESULTS Seed mass was related to maternal age and growth at the time of seed production; i.e., slow-growing, older mothers had smaller seeds, and fast-growing, young mothers had larger seeds, which could be interpreted either as a proxy of senescence or as a maternal strategy. Seed mass had a positive effect on germination success, but aside from differences in seed mass, maternal age had a negative effect and diameter had a positive effect on germination timing and subsequent survival. CONCLUSIONS The results highlight the importance of maternal conditions combined with seed mass in shaping seedling establishment. Our findings open new insights in the offspring performance deriving from long-term canopy seed banks, which may have high relevance for plant adaptation.
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Affiliation(s)
- Marta Callejas‐Díaz
- Department of Forest Ecology and GeneticsForest Research Centre, National Institute for Agricultural and Food Research and Technology (INIA‐CSIC)MadridSpain
| | - M. Regina Chambel
- Department of Forest Ecology and GeneticsForest Research Centre, National Institute for Agricultural and Food Research and Technology (INIA‐CSIC)MadridSpain
| | - Javier San‐Martín‐Lorén
- Department of Forest Ecology and GeneticsForest Research Centre, National Institute for Agricultural and Food Research and Technology (INIA‐CSIC)MadridSpain
| | - Guillermo Gea‐Izquierdo
- Department of Forest Ecology and GeneticsForest Research Centre, National Institute for Agricultural and Food Research and Technology (INIA‐CSIC)MadridSpain
| | - Luis Santos‐Del‐Blanco
- Department of Forest Ecology and GeneticsForest Research Centre, National Institute for Agricultural and Food Research and Technology (INIA‐CSIC)MadridSpain
| | - Erik Postma
- Centre for Ecology and ConservationUniversity of ExeterPenrynUK
| | - José M. Climent
- Department of Forest Ecology and GeneticsForest Research Centre, National Institute for Agricultural and Food Research and Technology (INIA‐CSIC)MadridSpain
- Sustainable Forest Management Research InstituteUniversity of Valladolid‐National Institute for Agricultural and Food Research and TechnologyPalenciaSpain
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Di Santo LN, Polgar M, Nies S, Hodgkiss P, Canning CA, Wright JW, Hamilton JA. Seed morphological traits as a tool to quantify variation maintained in ex situ collections: a case study in Pinus torreyana. AOB PLANTS 2021; 13:plab058. [PMID: 34594485 PMCID: PMC8477307 DOI: 10.1093/aobpla/plab058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 09/07/2021] [Indexed: 05/30/2023]
Abstract
Understanding the within- and among-population distribution of trait variation within seed collections may provide a means to approximate standing genetic variation and inform plant conservation. This study aimed to estimate population- and family-level seed trait variability for existing seed collections of Torrey pine (Pinus torreyana), and to use these data to guide sampling of future collections. We quantified variation in 14 seed morphological traits and seedling emergence within and among Torrey pine populations. Using a simulation-based approach, we used estimates of within-population variance to assess the number of maternal families required to capture 95 % of trait variation within each existing seed collection. Substantial structure was observed both within and among Torrey pine populations, with island and mainland seeds varying in seed size and seed coat thickness. Despite morphological differences, seedling emergence was similar across populations. Simulations revealed that 83 % and 71 % of all maternal families within island and mainland seed collections respectively needed to be resampled to capture 95 % of seed trait variation within existing collections. From a conservation perspective, our results indicate that to optimize genetic diversity captured in Torrey pine seed collections, maximizing the number of maternal families sampled within each population will be necessary.
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Affiliation(s)
- Lionel N Di Santo
- Department of Biological Sciences, North Dakota State University, Fargo, ND, USA
| | - Monica Polgar
- Department of Biological Sciences, North Dakota State University, Fargo, ND, USA
| | - Storm Nies
- Department of Biological Sciences, North Dakota State University, Fargo, ND, USA
| | - Paul Hodgkiss
- USDA Forest Service, Pacific Southwest Research Station, Davis, CA, USA
| | - Courtney A Canning
- USDA Forest Service, Pacific Southwest Research Station, Placerville, CA, USA
| | - Jessica W Wright
- USDA Forest Service, Pacific Southwest Research Station, Davis, CA, USA
| | - Jill A Hamilton
- Department of Biological Sciences, North Dakota State University, Fargo, ND, USA
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7
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The Effect of Seed Size on Germination and Seedling Growth in Sweet Chestnut (Castanea sativa Mill.). FORESTS 2021. [DOI: 10.3390/f12070858] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The quantity and quality of seedlings in the nursery has an impact on the success of re-establishment and later growth. High germination rates enable a sufficient number of seedlings, and their quality is assessed using a number of parameters, including seedling height and root collar diameter. These parameters are influenced in some species by seed size, but the correlation between them is species-specific. The model species in this research was sweet chestnut (Castaneasativa Mill.), and seeds from 12 populations from two distinct biogeographical regions of Croatia were collected. We examined the influence of seed size on four parameters: germination rate, seedling height, root collar diameter and sturdiness quotient. Seed size has been shown to have a positive influence on both seedling height and root collar diameter, whereas no such correlation was noted for germination rate and sturdiness quotient. Significant differences in nut size and seedling growth parameters were found between the Mediterranean and continental populations, with higher values observed in the coastal Mediterranean populations. We concluded that seed origin and seed size have a significant impact on seedling growth and are important factors to consider when choosing seed material. Further nursery operations should consider seed origin and local environmental conditions when choosing seedlings for reforestation efforts and general forest operations.
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Gundel PE, Sun P, Charlton ND, Young CA, Miller TEX, Rudgers JA. Simulated folivory increases vertical transmission of fungal endophytes that deter herbivores and alter tolerance to herbivory in Poa autumnalis. ANNALS OF BOTANY 2020; 125:981-991. [PMID: 32010946 PMCID: PMC7218812 DOI: 10.1093/aob/mcaa021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 01/31/2020] [Indexed: 05/02/2023]
Abstract
BACKGROUND AND AIMS The processes that maintain variation in the prevalence of symbioses within host populations are not well understood. While the fitness benefits of symbiosis have clearly been shown to drive changes in symbiont prevalence, the rate of transmission has been less well studied. Many grasses host symbiotic fungi (Epichloë spp.), which can be transmitted vertically to seeds or horizontally via spores. These symbionts may protect plants against herbivores by producing alkaloids or by increasing tolerance to damage. Therefore, herbivory may be a key ecological factor that alters symbiont prevalence within host populations by affecting either symbiont benefits to host fitness or the symbiont transmission rate. Here, we addressed the following questions: Does symbiont presence modulate plant tolerance to herbivory? Does folivory increase symbiont vertical transmission to seeds or hyphal density in seedlings? Do plants with symbiont horizontal transmission have lower rates of vertical transmission than plants lacking horizontal transmission? METHODS We studied the grass Poa autumnalis and its symbiotic fungi in the genus Epichloë. We measured plant fitness (survival, growth, reproduction) and symbiont transmission to seeds following simulated folivory in a 3-year common garden experiment and surveyed natural populations that varied in mode of symbiont transmission. KEY RESULTS Poa autumnalis hosted two Epichloë taxa, an undescribed vertically transmitted Epichloë sp. PauTG-1 and E. typhina subsp. poae with both vertical and horizontal transmission. Simulated folivory reduced plant survival, but endophyte presence increased tolerance to damage and boosted fitness. Folivory increased vertical transmission and hyphal density within seedlings, suggesting induced protection for progeny of damaged plants. Across natural populations, the prevalence of vertical transmission did not correlate with symbiont prevalence or differ with mode of transmission. CONCLUSIONS Herbivory not only mediated the reproductive fitness benefits of symbiosis, but also promoted symbiosis prevalence by increasing vertical transmission of the fungus to the next generation. Our results reveal a new mechanism by which herbivores could influence the prevalence of microbial symbionts in host populations.
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Affiliation(s)
- Pedro E Gundel
- IFEVA-CONICET, Department of Ecology, College of Agronomy, University of Buenos Aires, Buenos Aires, Argentina
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
- For correspondence. E-mail
| | - Prudence Sun
- Department of Biosciences, Rice University, Houston, TX, USA
| | | | | | - Tom E X Miller
- Department of Biosciences, Rice University, Houston, TX, USA
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Traveset A, Escribano‐Avila G, Gómez JM, Valido A. Conflicting selection on
Cneorum tricoccon
(Rutaceae) seed size caused by native and alien seed dispersers. Evolution 2019; 73:2204-2215. [DOI: 10.1111/evo.13852] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 09/03/2019] [Accepted: 09/05/2019] [Indexed: 01/02/2023]
Affiliation(s)
- Anna Traveset
- Global Change Research GroupInstitut Mediterrani d'Estudis Avançats (CSIC‐UIB) 07190 Esporles Mallorca Balearic Islands Spain
| | - Gema Escribano‐Avila
- Global Change Research GroupInstitut Mediterrani d'Estudis Avançats (CSIC‐UIB) 07190 Esporles Mallorca Balearic Islands Spain
| | - José María Gómez
- Departamento Ecología Funcional y EvolutivaEstación Experimental de Zonas Áridas (EEZA‐CSIC) 04120 Almería Spain
| | - Alfredo Valido
- Instituto de Productos Naturales y Agrobiología (IPNA‐CSIC) 38206 La Laguna Tenerife Islas Canarias Spain
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Csilléry K, Ovaskainen O, Sperisen C, Buchmann N, Widmer A, Gugerli F. Adaptation to local climate in multi-trait space: evidence from silver fir (Abies alba Mill.) populations across a heterogeneous environment. Heredity (Edinb) 2019; 124:77-92. [PMID: 31182819 DOI: 10.1038/s41437-019-0240-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 05/08/2019] [Accepted: 05/22/2019] [Indexed: 01/13/2023] Open
Abstract
Heterogeneous environments, such as mountainous landscapes, create spatially varying selection pressure that potentially affects several traits simultaneously across different life stages, yet little is known about the general patterns and drivers of adaptation in such complex settings. We studied silver fir (Abies alba Mill.) populations across Switzerland and characterized its mountainous landscape using downscaled historical climate data. We sampled 387 trees from 19 populations and genotyped them at 374 single-nucleotide polymorphisms (SNPs) to estimate their demographic distances. Seedling morphology, growth and phenology traits were recorded in a common garden, and a proxy for water use efficiency was estimated for adult trees. We tested whether populations have more strongly diverged at quantitative traits than expected based on genetic drift alone in a multi-trait framework, and identified potential environmental drivers of selection. We found two main responses to selection: (i) populations from warmer and more thermally stable locations have evolved towards a taller stature, and (ii) the growth timing of populations evolved towards two extreme strategies, 'start early and grow slowly' or 'start late and grow fast', driven by precipitation seasonality. Populations following the 'start early and grow slowly' strategy had higher water use efficiency and came from inner Alpine valleys characterized by pronounced summer droughts. Our results suggest that contrasting adaptive life-history strategies exist in silver fir across different life stages (seedling to adult), and that some of the characterized populations may provide suitable seed sources for tree growth under future climatic conditions.
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Affiliation(s)
- Katalin Csilléry
- Center for Adaptation to a Changing Environment, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland. .,Swiss Federal Research Institute WSL, Birmensdorf, Switzerland. .,Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.
| | - Otso Ovaskainen
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.,Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | | | - Nina Buchmann
- Institute of Agricultural Sciences, ETH Zurich, Zurich, Switzerland
| | - Alex Widmer
- Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
| | - Felix Gugerli
- Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
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Rees M, Ellner SP. Why So Variable: Can Genetic Variance in Flowering Thresholds Be Maintained by Fluctuating Selection? Am Nat 2019; 194:E13-E29. [PMID: 31251648 DOI: 10.1086/703436] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We use integral projection models (IPMs) and individual-based simulations to study the evolution of genetic variance in two monocarpic plant systems. Previous approaches combining IPMs with an adaptive dynamics-style invasion analysis predicted that genetic variability in the size threshold for flowering will not be maintained, which conflicts with empirical evidence. We ask whether this discrepancy can be resolved by making more realistic assumptions about the underlying genetic architecture, assuming a multilocus quantitative trait in an outcrossing diploid species. To do this, we embed the infinitesimal model of quantitative genetics into an IPM for a size-structured cosexual plant species. The resulting IPM describes the joint dynamics of individual size and breeding value of the evolving trait. We apply this general framework to the monocarpic perennials Oenothera glazioviana and Carlina vulgaris. The evolution of heritable variation in threshold size is explored in both individual-based models (IBMs) and IPMs, using a mutation rate modifier approach. In the Oenothera model, where the environment is constant, there is selection against producing genetically variable offspring. In the Carlina model, where the environment varies between years, genetically variable offspring provide a selective advantage, allowing the maintenance of genetic variability. The contrasting predictions of adaptive dynamics and quantitative genetics models for the same system suggest that fluctuating selection may be more effective at maintaining genetic variation than previously thought.
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12
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Larios E, Venable DL. Selection for seed size: The unexpected effects of water availability and density. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13138] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Eugenio Larios
- Department of Ecology and Evolutionary Biology University of Arizona Tucson Arizona
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13
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Wang B, Ives AR. Tree-to-tree variation in seed size and its consequences for seed dispersal versus predation by rodents. Oecologia 2016; 183:751-762. [DOI: 10.1007/s00442-016-3793-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 12/04/2016] [Indexed: 10/20/2022]
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14
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Richardson BA, Ortiz HG, Carlson SL, Jaeger DM, Shaw NL. Genetic and environmental effects on seed weight in subspecies of big sagebrush: applications for restoration. Ecosphere 2015. [DOI: 10.1890/es15-00249.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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