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Blake-Mahmud J, Sessa EB, Visger CJ, Watkins JE. Polyploidy and environmental stress response: a comparative study of fern gametophytes. THE NEW PHYTOLOGIST 2024. [PMID: 39044655 DOI: 10.1111/nph.19969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 06/24/2024] [Indexed: 07/25/2024]
Abstract
Climate change is rapidly altering natural habitats and generating complex patterns of environmental stress. Ferns are major components of many forest understories and, given their independent gametophyte generation, may experience unique pressures in emerging temperature and drought regimes. Polyploidy is widespread in ferns and may provide a selective advantage in these rapidly changing environments. This work aimed to understand whether the gametophytes of allopolyploid ferns respond differently to climate-related physiological stress than their diploid parents. The experimental approach involved a multifactorial design with 27 treatment combinations including exposure to multiple levels of drought and temperature over three treatment durations, with recovery measured at multiple timepoints. We measured Chl fluorescence from over 2000 gametophytes to evaluate stress avoidance and tolerance in diploid and polyploid species. Polyploids generally showed a greater ability to avoid and/or tolerate a range of stress conditions compared with their diploid counterparts, suggesting that polyploidy may confer enhanced flexibility and resilience under climate stress. Overall, these results suggest that polyploidy may provide some resilience to climate change in mixed ploidy populations. However, all species remain susceptible to the impacts of extreme drought and heat stress.
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Affiliation(s)
| | - Emily B Sessa
- William & Lynda Steere Herbarium, New York Botanical Garden, Bronx, NY, 10458, USA
| | - Clayton J Visger
- Department of Biological Sciences, California State University, Sacramento, CA, 95819, USA
| | - James E Watkins
- Department of Biology, Colgate University, 13 Oak Drive, Hamilton, NY, 13346, USA
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2
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Travis J, Trexler JC. Phenotypic plasticity in the sailfin molly III: Geographic variation in reaction norms of growth and maturation to temperature and salinity. Ecol Evol 2024; 14:e11482. [PMID: 38826157 PMCID: PMC11140554 DOI: 10.1002/ece3.11482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 05/09/2024] [Accepted: 05/13/2024] [Indexed: 06/04/2024] Open
Abstract
Phenotypic plasticity, the ability of a single genotype to produce different phenotypes under different environmental conditions, plays a profound role in several areas of evolutionary biology. One important role is as an adaptation to a variable environment. While plasticity is extremely well documented in response to many environmental factors, there is controversy over how much of that plasticity is adaptive. Evidence is also mixed over how often conspecific populations display qualitative differences in the nature of plasticity. We present data on the reaction norms of growth and maturation to variation in temperature and salinity in male and female sailfin mollies (Poecilia latipinna) from three locally adjacent populations from South Carolina (SC). We compare these reaction norms to those previously reported in locally adjacent populations from north Florida (NF). In general, patterns of plasticity in fish from SC were similar to those in fish from NF. The magnitude of plasticity differed; fish from SC displayed less plasticity than fish from NF. This was because SC fish grew faster and matured earlier at the lower temperatures and salinities compared to NF fish. This is a countergradient pattern of variation, in which SC fish grew faster and matured earlier in conditions that would otherwise slow growth and delay maturity. Among fish from both regions, males were much less plastic than females, especially for length at maturity. While there was no detectable heterogeneity among populations from NF, males from one of the SC populations, which is furthest from the other two, displayed a qualitatively different response in age at maturity to temperature variation than did males from the other two SC populations. The pattern of population variation in plasticity within and among regions suggests that gene flow, which diminishes with distance in sailfin mollies, plays a critical role in constraining divergence in norms of reaction.
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Affiliation(s)
- Joseph Travis
- Department of Biological ScienceFlorida State UniversityTallahasseeFloridaUSA
| | - Joel C. Trexler
- Department of Biological ScienceFlorida State UniversityTallahasseeFloridaUSA
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3
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Pearse IS, McIntyre P, Cacho NI, Strauss SY. Fitness homeostasis across an experimental water gradient predicts species' geographic range and climatic breadth. Ecology 2022; 103:e3827. [PMID: 35857374 DOI: 10.1002/ecy.3827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 05/05/2022] [Accepted: 05/16/2022] [Indexed: 11/09/2022]
Abstract
Species range sizes and realized niche breadths vary tremendously. Understanding the source of this variation has been a long-term aim in evolutionary ecology and is a major tool in efforts to ameliorate the impacts of changing climates on species distributions. Species ranges that span a large climatic envelope can be achieved by a collection of specialized genotypes locally adapted to a small range of conditions, by genotypes with stable fitness across variable environments, or a combination of these factors. We asked whether fitness expressed along a key niche axis, water availability, could explain a species' realized niche breadth--its geographic range and climate breadth-- in 11 species from a clade of jewelflowers whose range sizes vary by two orders of magnitude. Specifically, we explored whether the range size of a species was related to the ability of genotypes (maternal families) to maintain fitness across a range of experimental water availabilities based on 30-year historical field precipitation regimes. We operationally characterized fitness homeostasis through the coefficient of variation (CV) in fitness of a genotype (family) across the experimental water gradient. We found that species with genotypes that had high fitness homeostasis -- low variation in fitness over our treatments --had larger climatic niche breadth and geographic range in their field distributions. The result was robust to alternate measures of fitness homeostasis. Our results show that the fitness homeostasis of genotypes can be a major factor contributing to niche breadth and range size in this clade. Fitness homeostasis can buffer species from loss of genetic diversity and under changing climates, provides time for adaptation to future conditions.
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Affiliation(s)
- Ian S Pearse
- U.S. Geological Survey, Fort Collins Science Center, 2150 Centre Ave #C, Ft Collins, CO 80526, USA
| | - Patrick McIntyre
- Nature Serve, Western Regional Office, 1680 38th St., Suite 120, Boulder, Colorado, USA
| | - N Ivalú Cacho
- Instituto de Biología, 3er Circuito de CU s/n, Universidad Nacional Autónoma de México, Copilco Coyoacán, Universidad Nacional Autónoma de México, CDMX 04510, Mexico
| | - Sharon Y Strauss
- Center for Population Biology and Department of Evolution and Ecology, University of California, Davis, CA, USA
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Nitta JH, Chambers SM. Identifying cryptic fern gametophytes using DNA barcoding: A review. APPLICATIONS IN PLANT SCIENCES 2022; 10:e11465. [PMID: 35495195 PMCID: PMC9039790 DOI: 10.1002/aps3.11465] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 12/09/2021] [Accepted: 12/11/2021] [Indexed: 05/14/2023]
Abstract
Ferns and lycophytes are unique among land plants in having sporophyte (diploid) and gametophyte (haploid) generations that can grow independently of each other. While most studies of fern ecology focus on the more visible sporophytic stage, the gametophyte is critically important, as it is the sexual phase of the life cycle. Yet, fern gametophytes have long been neglected in field studies due to their small size and cryptic morphology. DNA barcoding is a powerful method that can be used to identify field-collected gametophytes to species and allow for detailed study of their ecology. Here, we review the state of DNA barcoding as applied to fern gametophytes. First, we trace the history of DNA barcoding and how it has come to be applied to fern gametophytes. Next, we summarize case studies that show how DNA barcoding has been used to better understand fern species distributions, gametophyte ecology, and community ecology. Finally, we propose avenues for future research using this powerful tool, including next-generation DNA sequencing for in-field identification of cryptic gametophytes.
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Affiliation(s)
- Joel H. Nitta
- Department of Biological Sciences, Graduate School of ScienceThe University of Tokyo2‐11‐16 Yayoi, Bunkyo‐kuTokyo113‐0032Japan
| | - Sally M. Chambers
- Marie Selby Botanical GardensBotany DepartmentSarasotaFlorida34236USA
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5
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Krieg CP, Chambers SM. The ecology and physiology of fern gametophytes: A methodological synthesis. APPLICATIONS IN PLANT SCIENCES 2022; 10:e11464. [PMID: 35495196 PMCID: PMC9039797 DOI: 10.1002/aps3.11464] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 12/21/2021] [Accepted: 01/10/2022] [Indexed: 05/14/2023]
Abstract
All green plants alternate between the gametophyte and sporophyte life stages, but only seed-free vascular plants (ferns and lycophytes) have independent, free-living gametophytes. Fern and lycophyte gametophytes are significantly reduced in size and morphological complexity relative to their sporophytic counterparts and have often been overlooked in ecological and physiological studies. Understanding the ecological and physiological factors that directly impact this life stage is of critical importance because the ultimate existence of a sporophyte is dependent upon successful fertilization in the gametophyte generation. Furthermore, previous research has shown that the dual nature of the life cycle and the high dispersibility of spores can result in different geographic patterns between gametophytes and their respective sporophytes. This variation in distribution patterns likely exacerbates the separation of selective pressures acting on gametophyte and sporophyte generations, and can uniquely impact a species' ecology and physiology. Here, we provide a review of historical and contemporary methodologies used to examine ecological and physiological aspects of fern gametophytes, as well as those that allow for comparisons between the two generations. We conclude by suggesting methodological approaches to answer currently outstanding questions. We hope that the information covered herein will serve as a guide to current researchers and stimulate future discoveries in fern gametophyte ecology and physiology.
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Affiliation(s)
| | - Sally M. Chambers
- Department of BotanyMarie Selby Botanical GardensSarasotaFlorida34236USA
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Draining the Swamping Hypothesis: Little Evidence that Gene Flow Reduces Fitness at Range Edges. Trends Ecol Evol 2021; 36:533-544. [DOI: 10.1016/j.tree.2021.02.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 01/27/2021] [Accepted: 02/05/2021] [Indexed: 11/23/2022]
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Liu W, Xu J, Fu W, Wang X, Lei C, Chen Y. Evidence of stress imprinting with population-level differences in two moss species. Ecol Evol 2019; 9:6329-6341. [PMID: 31236224 PMCID: PMC6580294 DOI: 10.1002/ece3.5205] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 03/26/2019] [Accepted: 04/05/2019] [Indexed: 11/08/2022] Open
Abstract
Plants are often repeatedly exposed to stresses during their lives and have a mechanism called stress imprinting that provides "memories" of stresses they experience and increases their ability to cope with later stresses. To test hypotheses that primed bryophytes can preserve their stress imprinting after 6 days of recovery and induce higher levels of osmolytes and ROS-scavenging activities upon later stress exposure, and there exist population-level differentiation in their desiccation defenses, we transplanted samples of two populations of each of two moss species, Hypnum plumaeforme and Pogonatum cirratum, in a nature reserve in southern China. After 16 months of acclimation, sets of each population were subjected to control, one-time desiccation stress, duplicated desiccation stress and cross-stress (low temperature stress followed by desiccation stress) treatments. Levels of oxidant enzymes, osmolytes, and phytohormones in the samples were then determined. The desiccation stress generally led to increases in activities or contents of superoxide dismutase, guaiacol peroxidase, catalase, proline, soluble sugars, soluble proteins, and stress hormones including abscisic acid (ABA), jasmonates (JA), and salicylic acid (SA), with differences between both species and populations. After a 6-day recovery period, contents of phytohormones (including ABA, JA, SA, and cytokinins) in stressed H. plumaeforme had substantially fallen toward control levels. The duplicated and cross-stress treatments generally led to further accumulation of proline, soluble sugars, and soluble proteins, with further increases in activities of antioxidant enzymes in some cases. Furthermore, significant differences between allochthonous and native populations were found in contents of malondialdehyde and osmolytes, as well as antioxidant enzyme activities. Our results confirm the hypotheses and highlight the importance of osmolytes in mosses' stress responses.
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Affiliation(s)
- Weiqiu Liu
- Guangdong Key Laboratory of Plant Resources, School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Jianqu Xu
- Guangdong Key Laboratory of Plant Resources, School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Wei Fu
- Guangdong Key Laboratory of Plant Resources, School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Xiangyuan Wang
- Guangdong Key Laboratory of Plant Resources, School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Chunyi Lei
- Department of Scientific Research and EducationHeishiding Nature ReserveZhaoqingChina
| | - Yunfeng Chen
- Guangdong Key Laboratory of Plant Resources, School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
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Fawcett S, Sistla S, Dacosta‐Calheiros M, Kahraman A, Reznicek AA, Rosenberg R, von Wettberg EJB. Tracking microhabitat temperature variation with iButton data loggers. APPLICATIONS IN PLANT SCIENCES 2019; 7:e01237. [PMID: 31024781 PMCID: PMC6476170 DOI: 10.1002/aps3.1237] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 01/07/2019] [Indexed: 05/11/2023]
Abstract
PREMISE OF THE STUDY Fine-scale variation in temperature and soil moisture contribute to microhabitats across the landscape, affecting plant phenology, distribution, and fitness. The recent availability of compact and inexpensive temperature and humidity data loggers such as iButtons has facilitated research on microclimates. METHODS AND RESULTS Here, we highlight the use of iButtons in three distinct settings: comparisons of empirical data to modeled climate data for rare rock ferns in the genus Asplenium in eastern North America; generation of fine-scale data to predict flowering time and vernalization responsiveness of crop wild relatives of chickpea from southeastern Anatolia; and measurements of extreme thermal variation of solar array installations in Vermont. DISCUSSION We highlight a range of challenges with iButtons, including serious limitations of the Hygrochron function that affect their utility for measuring soil moisture, and methods for protecting them from the elements and from human interference. Finally, we provide MATLAB code to facilitate the processing of raw iButton data.
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Affiliation(s)
- Susan Fawcett
- Pringle Herbarium, Department of Plant BiologyUniversity of Vermont63 Carrigan DriveBurlingtonVermont05401USA
| | - Seeta Sistla
- Biological and Life SciencesHampshire College893 West StreetAmherstMassachusetts01002USA
| | - Manny Dacosta‐Calheiros
- Biological SciencesFlorida International University11200 SW 8th Street (CP‐304)MiamiFlorida33199USA
| | - Abdullah Kahraman
- Department of Field CropsHarran UniversityOsmanbey YerleşkesiŞanlıurfa‐Mardin Karayolu Üzeri 18 Km63300ŞanlıurfaTurkey
| | - Anton A. Reznicek
- University of Michigan Herbarium3600 Varsity DriveAnn ArborMichigan48108USA
| | - Rachel Rosenberg
- Biological and Life SciencesHampshire College893 West StreetAmherstMassachusetts01002USA
| | - Eric J. B. von Wettberg
- Biological SciencesFlorida International University11200 SW 8th Street (CP‐304)MiamiFlorida33199USA
- Department of Plant and Soil ScienceUniversity of Vermont63 Carrigan DriveBurlingtonVermont05401USA
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9
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Tittes SB, Walker JF, Torres-Martínez L, Emery NC. Grow Where You Thrive, or Where Only You Can Survive? An Analysis of Performance Curve Evolution in a Clade with Diverse Habitat Affinities. Am Nat 2019; 193:530-544. [PMID: 30912965 DOI: 10.1086/701827] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Performance curves are valuable tools for quantifying the fundamental niches of organisms and testing hypotheses about evolution, life-history trade-offs, and the drivers of variation in species' distribution patterns. Here, we present a novel Bayesian method for characterizing performance curves that facilitates comparisons among species. We then use this model to quantify and compare the hydrological performance curves of 14 different taxa in the genus Lasthenia, an ecologically diverse clade of plants that collectively occupy a variety of habitats with unique hydrological features, including seasonally flooded wetlands called vernal pools. We conducted a growth chamber experiment to measure each taxon's fitness across five hydrological treatments that ranged from severe drought to extended flooding, and we identified differences in hydrological performance curves that explain their associations with vernal pool and terrestrial habitats. Our analysis revealed that the distribution of vernal pool taxa in the field does not reflect their optimal hydrological environments: all taxa, regardless of habitat affinity, have highest fitness under similar hydrological conditions of saturated soil without submergence. We also found that a taxon's relative position across flood gradients within vernal pools is best predicted by the height of its performance curve. These results demonstrate the utility of our approach for generating insights into when and how performance curves evolve among taxa as they diversify into distinct environments. To facilitate its use, the modeling framework has been developed into an R package.
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Chambers SM, Emery NC. Conserved thermal performance curves across the geographic range of a gametophytic fern. AOB PLANTS 2018; 10:ply050. [PMID: 30338048 PMCID: PMC6185718 DOI: 10.1093/aobpla/ply050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 09/10/2018] [Indexed: 05/12/2023]
Abstract
Species-level responses to environmental change depend on the collective responses of their constituent populations and the degree to which populations are specialized to local conditions. Manipulative experiments in common-garden settings make it possible to test for population variation in species' responses to specific climate variables, including those projected to shift as the climate changes in the future. While this approach is being applied to a variety of plant taxa to evaluate their responses to climate change, these studies are heavily biased towards seed-bearing plant species. Given several unique morphological and physiological traits, fern species may exhibit very different responses from angiosperms and gymnosperms. Here, we tested the hypothesis that previously detected population differentiation in a fern species is due to differentiation in thermal performance curves among populations. We collected explants from six populations spanning the species' geographic range and exposed them to 10 temperature treatments. Explant survival, lifespan and the change in photosynthetic area were analysed as a function of temperature, source population and their interaction. Overall results indicated that explants performed better at the lowest temperature examined, and the threshold for explant performance reflects maximum temperatures likely to be experienced in the field. Surprisingly, explant fitness did not differ among source populations, suggesting that temperature is not the driver behind previously detected patterns of population differentiation. These results highlight the importance of other environmental axes in driving population differentiation across a species range, and suggest that the perennial life history strategy, asexual mating system and limited dispersal potential of Vittaria appalachiana may restrict the rise and differentiation of adaptive genetic variation in thermal performance traits among populations.
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Affiliation(s)
- Sally M Chambers
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
- Corresponding author’s email address:
| | - Nancy C Emery
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
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11
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Gorton AJ, Moeller DA, Tiffin P. Little plant, big city: a test of adaptation to urban environments in common ragweed ( Ambrosia artemisiifolia). Proc Biol Sci 2018; 285:20180968. [PMID: 30051853 PMCID: PMC6030533 DOI: 10.1098/rspb.2018.0968] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 06/06/2018] [Indexed: 11/12/2022] Open
Abstract
A full understanding of how cities shape adaptation requires characterizing genetically-based phenotypic and fitness differences between urban and rural populations under field conditions. We used a reciprocal transplant experiment with the native plant common ragweed, (Ambrosia artemisiifolia), and found that urban and rural populations have diverged in flowering time, a trait that strongly affects fitness. Although urban populations flowered earlier than rural populations, plants growing in urban field sites flowered later than plants in rural field sites. This counter-gradient variation is consistent adaptive divergence between urban and rural populations. Also consistent with local adaptation, both urban and rural genotypes experienced stronger net selection in the foreign than in the local habitat, but this pattern was not significant for male fitness. Despite the evidence for local adaptation, rural populations had higher lifetime fitness at all sites, suggesting that selection has been stronger or more uniform in rural than urban populations. We also found that inter-population differences in both flowering time and fitness tended to be greater among urban than rural populations, which is consistent with greater drift or spatial variation in selection within urban environments. In summary, our results are consistent with adaptive divergence of urban and rural populations, but also suggest there may be greater environmental heterogeneity in urban environments which also affects evolution in urban landscapes.
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Affiliation(s)
- Amanda J Gorton
- Department of Ecology, Evolution and Behavior, University of Minnesota, 1987 Upper Buford Circle, St Paul, MN 55108, USA
| | - David A Moeller
- Department of Plant and Microbial Biology, University of Minnesota, 1479 Gortner Avenue, St Paul, MN 55108, USA
| | - Peter Tiffin
- Department of Plant and Microbial Biology, University of Minnesota, 1479 Gortner Avenue, St Paul, MN 55108, USA
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Wickell DA, Windham MD, Wang X, Macdonald SJ, Beck JB. Can asexuality confer a short-term advantage? Investigating apparent biogeographic success in the apomictic triploid fern Myriopteris gracilis. AMERICAN JOURNAL OF BOTANY 2017; 104:1254-1265. [PMID: 28814405 PMCID: PMC6013364 DOI: 10.3732/ajb.1700126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 07/03/2017] [Indexed: 05/16/2023]
Abstract
PREMISE OF THE STUDY Although asexual taxa are generally seen as evolutionary dead ends, asexuality appears to provide a short-term benefit in some taxa, including a wider geographic distribution compared to sexual relatives. However, this may be an illusion created by multiple, morphologically cryptic, asexual lineages, each occupying a relatively small area. In this study we investigate the role of multiple lineages in the biogeography of Myriopteris gracilis Fée (Pteridaceae), a North American apomictic triploid fern species with a particularly large range. METHODS Range-wide asexuality was assessed by counting spores/sporangium in 606 Myriopteris gracilis specimens from across the species range, and lineage structure was assessed with both plastid DNA sequence and Genotyping By Sequencing (GBS) SNP datasets. KEY RESULTS Spore counting of >600 specimens identified no sexual populations, establishing that Myriopteris gracilis is exclusively asexual. The plastid data estimated the crown age of M. gracilis at ca. 2.5 mya and identified two lineages, each largely confined to the eastern or western portions of the range. These groups were further subdivided by the GBS data, revealing at least seven asexual lineages of varying geographic distributions, each occupying a relatively small portion of the total range of M. gracilis. CONCLUSIONS Although maintained exclusively through asexual reproduction, the broad distribution of Myriopteris gracilis is a compilation of numerous, independently formed asexual lineages. Since no single asexual lineage occupies the full extent of the species distribution, recurrent lineage formation should be considered when evaluating the short-term benefit of asexuality in this taxon and others.
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Affiliation(s)
- David A. Wickell
- Department of Biological Science, Wichita State University, Wichita, Kansas 67260 USA
| | - Michael D. Windham
- Department of Biological Science, Duke University, Durham, North Carolina 27708 USA
| | - Xiaofei Wang
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045 USA
| | - Stuart J. Macdonald
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045 USA
| | - James B. Beck
- Department of Biological Science, Wichita State University, Wichita, Kansas 67260 USA
- Botanical Research Institute of Texas, Fort Worth, Texas 76107 USA
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14
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Yang LN, Zhu W, Wu EJ, Yang C, Thrall PH, Burdon JJ, Jin LP, Shang LP, Zhan J. Trade-offs and evolution of thermal adaptation in the Irish potato famine pathogen Phytophthora infestans. Mol Ecol 2016; 25:4047-58. [PMID: 27288627 DOI: 10.1111/mec.13727] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 05/23/2016] [Accepted: 05/26/2016] [Indexed: 01/07/2023]
Abstract
Temperature is one of the most important environmental parameters with crucial impacts on nearly all biological processes. Due to anthropogenic activity, average air temperatures are expected to increase by a few degrees in coming decades, accompanied by an increased occurrence of extreme temperature events. Such global trends are likely to have various major impacts on human society through their influence on natural ecosystems, food production and biotic interactions, including diseases. In this study, we used a combination of statistical genetics, experimental evolution and common garden experiments to investigate the evolutionary potential for thermal adaptation in the potato late blight pathogen, Phytophthora infestans, and infer its likely response to changing temperatures. We found a trade-off associated with thermal adaptation to heterogeneous environments in P. infestans, with the degree of the trade-off peaking approximately at the pathogen's optimum growth temperature. A genetic trade-off in thermal adaptation was also evidenced by the negative association between a strain's growth rate and its thermal range for growth, and warm climates selecting for a low pathogen growth rate. We also found a mirror effect of phenotypic plasticity and genetic adaptation on growth rate. At below the optimum, phenotypic plasticity enhances pathogen's growth rate but nature selects for slower growing genotypes when temperature increases. At above the optimum, phenotypic plasticity reduces pathogen's growth rate but natural selection favours for faster growing genotypes when temperature increases further. We conclude from these findings that the growth rate of P. infestans will only be marginally affected by global warming.
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Affiliation(s)
- Li-Na Yang
- Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Wen Zhu
- Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - E-Jiao Wu
- Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Ce Yang
- Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Peter H Thrall
- CSIRO Agriculture, PO Box 1600, Canberra, Australian Capital Territory, 2601, Australia
| | - Jeremy J Burdon
- CSIRO Agriculture, PO Box 1600, Canberra, Australian Capital Territory, 2601, Australia
| | - Li-Ping Jin
- Institute of Flowers and Vegetables, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Li-Ping Shang
- Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jiasui Zhan
- Key Lab for Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
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15
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Farrar DR. Vittaria appalachiana continues to provide insight into the biology of ferns: A commentary on two studies recently published in American Journal of Botany. AMERICAN JOURNAL OF BOTANY 2016; 103:593-595. [PMID: 27056930 DOI: 10.3732/ajb.1500323] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 09/30/2015] [Indexed: 06/05/2023]
Affiliation(s)
- Donald R Farrar
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, Iowa 50011 USA
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16
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Etterson JR, Schneider HE, Gorden NLS, Weber JJ. Evolutionary insights from studies of geographic variation: Contemporary variation and looking to the future. AMERICAN JOURNAL OF BOTANY 2016; 103:5-9. [PMID: 26772310 DOI: 10.3732/ajb.1500515] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 12/16/2015] [Indexed: 06/05/2023]
Abstract
In an age of rapid global change, it is imperative that we continue to improve our understanding of factors that govern genetic differentiation in plants to inform biologically reasonable predictions for the future and enlighten conservation and restoration practices. In this special issue, we have assembled a set of original research and reviews that employ diverse approaches, both classic and contemporary, to illuminate patterns of phenotypic and genetic variation, probe the underlying evolutionary processes that have contributed to these patterns, build predictive models, and test evolutionary hypotheses. Our goal was to underscore the unique insights that can be obtained through the complementary and distinct studies of plant populations across species' geographic ranges.
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Affiliation(s)
- Julie R Etterson
- Department of Biology, University of Minnesota Duluth, 207A Swenson Science Building, Duluth, Minnesota 55812 USA
| | - Heather E Schneider
- Department of Ecology, Evolution & Marine Biology, University of California, Santa Barbara, Santa Barbara, California 93106 USA
| | - Nicole L Soper Gorden
- Department of Biology, University of Minnesota Duluth, 207A Swenson Science Building, Duluth, Minnesota 55812 USA
| | - Jennifer J Weber
- Department of Biology, Fordham University, Bronx, New York 10458; current address: Southern Illinois University, Carbondale, Illinois 62901 USA
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Sexton JP, Dickman EE. What can local and geographic population limits tell us about distributions? AMERICAN JOURNAL OF BOTANY 2016; 103:129-139. [PMID: 26772307 DOI: 10.3732/ajb.1500224] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 12/28/2016] [Indexed: 06/05/2023]
Abstract
PREMISE OF THE STUDY Understanding the evolutionary and ecological factors that determine plant distributions is of primary importance in botanical research. These factors may vary in predictable ways across different spatial scales, and thus, we can leverage scale to reveal the underlying processes limiting plant distributions. METHODS We review various research considerations across local and geographic scales, including the investigation of dispersal and habitat limitation, evolutionary factors, abiotic and biotic factors, and research logistics. We also present two case studies, slender monkeyflower (Mimulus leptaleus) and cut-leaf monkeyflower (Mimulus laciniatus), in the California Sierra Nevada. KEY RESULTS At a local spatial scale (within 50 m), no seeds were produced from plants sown at sites located just beyond known patches of M. leptaleus, but within the species' geographic range. At a much broader spatial scale (kilometers), at the highest and lowest elevations of the species' range, we found greatly reduced abundance and fecundity in plants sown outside of the geographic range limits of M. laciniatus. CONCLUSIONS These cases illustrate two contrasting spatial scales, yet agree in their illustration of strong habitat limitation. We end by discussing future avenues of research and by suggesting ways botanical researchers can frame their studies to maximize information gained on species requirements, distribution limits, and conservation among varying spatial scales.
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Affiliation(s)
- Jason P Sexton
- School of Natural Sciences, 5200 North Lake Road, University of California, Merced, California 95343 USA
| | - Erin E Dickman
- School of Natural Sciences, 5200 North Lake Road, University of California, Merced, California 95343 USA
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