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Bliard L, Martin JS, Paniw M, Blumstein DT, Martin JGA, Pemberton JM, Nussey DH, Childs DZ, Ozgul A. Detecting context dependence in the expression of life history trade-offs. J Anim Ecol 2024. [PMID: 39221784 DOI: 10.1111/1365-2656.14173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 08/11/2024] [Indexed: 09/04/2024]
Abstract
Life history trade-offs are one of the central tenets of evolutionary demography. Trade-offs, depicting negative covariances between individuals' life history traits, can arise from genetic constraints, or from a finite amount of resources that each individual has to allocate in a zero-sum game between somatic and reproductive functions. While theory predicts that trade-offs are ubiquitous, empirical studies have often failed to detect such negative covariances in wild populations. One way to improve the detection of trade-offs is by accounting for the environmental context, as trade-off expression may depend on environmental conditions. However, current methodologies usually search for fixed covariances between traits, thereby ignoring their context dependence. Here, we present a hierarchical multivariate 'covariance reaction norm' model, adapted from Martin (2023), to help detect context dependence in the expression of life-history trade-offs using demographic data. The method allows continuous variation in the phenotypic correlation between traits. We validate the model on simulated data for both intraindividual and intergenerational trade-offs. We then apply it to empirical datasets of yellow-bellied marmots (Marmota flaviventer) and Soay sheep (Ovis aries) as a proof-of-concept showing that new insights can be gained by applying our methodology, such as detecting trade-offs only in specific environments. We discuss its potential for application to many of the existing long-term demographic datasets and how it could improve our understanding of trade-off expression in particular, and life history theory in general.
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Affiliation(s)
- Louis Bliard
- Department of Evolutionary Biology and Environmental Studies, Zurich University, Zurich, Switzerland
| | - Jordan S Martin
- Institute of Evolutionary Medicine, Zurich University, Zurich, Switzerland
| | - Maria Paniw
- Department of Evolutionary Biology and Environmental Studies, Zurich University, Zurich, Switzerland
- Department of Conservation Biology, Estación Biológica de Doñana (EBD-CSIC), Seville, Spain
| | - Daniel T Blumstein
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, California, Los Angeles, USA
- The Rocky Mountain Biological Laboratory, Crested Butte, Colorado, USA
| | - Julien G A Martin
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Daniel H Nussey
- Institute of Ecology and Evolution, University of Edinburgh, Edinburgh, UK
| | - Dylan Z Childs
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Arpat Ozgul
- Department of Evolutionary Biology and Environmental Studies, Zurich University, Zurich, Switzerland
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Stephens RE, Gallagher RV, Méndez M, Sauquet H. Zygomorphic flowers last longer: the evolution of floral symmetry and floral longevity. Biol Lett 2024; 20:20240082. [PMID: 38889773 DOI: 10.1098/rsbl.2024.0082] [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: 02/16/2024] [Accepted: 05/07/2024] [Indexed: 06/20/2024] Open
Abstract
Floral longevity, the length of time a flower remains open and functional, is a phylogenetically conserved trait that balances floral costs against the rate at which flowers are pollinated. Floral symmetry has long been considered a key trait in floral evolution. Although zygomorphic (bilaterally symmetric) flowers typically receive fewer floral visitors than actinomorphic (radially symmetric) flowers, it is yet to be determined whether this could be associated with longer floral longevity. Using newly collected field data combined with data from the literature on 1452 species in 168 families, we assess whether floral longevity covaries with floral symmetry in a phylogenetic framework. We find that zygomorphic flowers last on average 1.1 days longer than actinomorphic flowers, a 26.5% increase in longevity, with considerable variation across both groups. Our results provide a basis to discuss the ecological and evolutionary costs of zygomorphy for plants. Despite these costs, zygomorphy has evolved numerous times throughout angiosperm history, and we discuss which rewards may outweigh the costs of slower pollination in zygomorphic flowers.
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Affiliation(s)
- R E Stephens
- School of Natural Sciences, Macquarie University , Ryde, New South Wales, Australia
- National Herbarium of NSW, Botanic Gardens of Sydney , Mount Annan, New South Wales, Australia
| | - R V Gallagher
- School of Natural Sciences, Macquarie University , Ryde, New South Wales, Australia
- Hawkesbury Institute for the Environment, Western Sydney University , Richmond, New South Wales, Australia
| | - M Méndez
- Area of Biodiversity and Conservation, Universidad Rey Juan Carlos , Madrid, Spain
| | - H Sauquet
- National Herbarium of NSW, Botanic Gardens of Sydney , Mount Annan, New South Wales, Australia
- Evolution & Ecology Research Centre, University of New South Wales , Sydney, New South Wales, Australia
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3
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Bliard L, Paniw M, Childs DZ, Ozgul A. Population Dynamic Consequences of Context-Dependent Trade-Offs across Life Histories. Am Nat 2024; 203:681-694. [PMID: 38781530 DOI: 10.1086/730111] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
AbstractTrade-offs are central to life history theory and play a role in driving life history diversity. They arise from a finite amount of resources that need to be allocated among different functions by an organism. Yet covariation of demographic rates among individuals frequently do not reflect allocation trade-offs because of variation in resource acquisition. The covariation of traits among individuals can thus vary with the environment and often increases in benign environments. Surprisingly, little is known about how such context-dependent expression of trade-offs among individuals affect population dynamics across species with different life histories. To study their influence on population stability, we develop an individual-based simulation where covariation in demographic rates varies with the environment. We use it to simulate population dynamics for various life histories across the slow-fast pace-of-life continuum. We found that the population dynamics of slower life histories are relatively more sensitive to changes in covariation, regardless of the trade-off considered. Additionally, we found that the impact on population stability depends on which trade-off is considered, with opposite effects of intraindividual and intergenerational trade-offs. Last, the expression of different trade-offs can feed back to influence generation time through selection acting on individual heterogeneity within cohorts, ultimately affecting population dynamics.
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Zhong D, Chi Y, Ding J, Zhao N, Zeng L, Liu P, Huang Z, Zhou L. Decoupling of nitrogen allocation and energy partitioning in rice after flowering. Ecol Evol 2024; 14:e11297. [PMID: 38623520 PMCID: PMC11017445 DOI: 10.1002/ece3.11297] [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: 05/16/2023] [Revised: 03/28/2024] [Accepted: 04/04/2024] [Indexed: 04/17/2024] Open
Abstract
Estimation of energy partitioning at leaf scale, such as fluorescence yield (ΦF) and photochemical yield (ΦP), is crucial to tracking vegetation gross primary productivity (GPP) at global scale. Nitrogen is an important participant in the process of light capture, electron transfer, and carboxylation in vegetation photosynthesis. However, the quantitative relationship between leaf nitrogen allocation and leaf energy partitioning remains unexplored. Here, a field experiment was established to explore growth stage variations in energy partitioning and nitrogen allocation at leaf scale using active fluorescence detection and photosynthetic gas exchange method in rice in the subtropical region of China. We observed a strongly positive correlation between the investment proportion of leaf nitrogen in photosynthetic system and ΦF during the vegetative growth stage. There were significant differences in leaf energy partitioning, leaf nitrogen allocation, and the relationship between ΦF and ΦP before and after flowering. Furthermore, flowering weakened the correlation between the investment proportion of leaf nitrogen in photosynthetic system and ΦF. These findings highlight the crucial role of phenological factors in exploring seasonal photosynthetic dynamics and carbon fixation of ecosystems.
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Affiliation(s)
- Duwei Zhong
- College of Geography and Environmental SciencesZhejiang Normal UniversityJinhuaChina
| | - Yonggang Chi
- College of Geography and Environmental SciencesZhejiang Normal UniversityJinhuaChina
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingChina
| | - Jianxi Ding
- College of Geography and Environmental SciencesZhejiang Normal UniversityJinhuaChina
| | - Ning Zhao
- College of Geography and Environmental SciencesZhejiang Normal UniversityJinhuaChina
| | - Linhui Zeng
- College of Geography and Environmental SciencesZhejiang Normal UniversityJinhuaChina
| | - Pai Liu
- College of Geography and Environmental SciencesZhejiang Normal UniversityJinhuaChina
| | - Zhi Huang
- College of Geography and Environmental SciencesZhejiang Normal UniversityJinhuaChina
| | - Lei Zhou
- College of Geography and Environmental SciencesZhejiang Normal UniversityJinhuaChina
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingChina
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Spigler RB, Maguiña R. Changes in female function and autonomous selfing across floral lifespan interact to drive variation in the cost of selfing. AMERICAN JOURNAL OF BOTANY 2022; 109:616-627. [PMID: 35075632 PMCID: PMC9315013 DOI: 10.1002/ajb2.1816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 12/29/2021] [Accepted: 12/30/2021] [Indexed: 06/14/2023]
Abstract
PREMISE Morphological and developmental changes as flowers age can impact patterns of mating. At the same time, direct or indirect costs of floral longevity can alter their fitness outcomes. This influence has been less appreciated, particularly with respect to the timing of selfing. We investigated changes in stigma events, autonomous selfing, outcross seed set capacity, and autofertility-a measure representing the potential for reproductive assurance-across floral lifespan in the mixed-mating biennial Sabatia angularis. METHODS We examined stigma morphology and receptivity, autonomous self-pollen deposition, and seed number and size under autonomous self-pollination and hand outcross-pollination for flowers of different ages, from 1 d of female phase until 14 d. We compared autonomous seed production to maximal outcross seed production at each flower age to calculate an index of autofertility. RESULTS The stigmatic lobes begin to untwist 1 d post anthesis. They progressively open, sextend, coil, and increase in receptivity, peaking or saturating at 8-11 d, depending on the measure. Autonomous seed production can occur early, but on average remains low until 6 d, when it doubles. In contrast, outcross seed number and size start out high, then decline precipitously. Consequently, autofertility increases steeply across floral lifespan. CONCLUSIONS Changes in stigma morphology and receptivity, timing of autonomous self-pollen deposition, and floral senescence can interact to influence the relative benefit of autonomous selfing across floral lifespan. Our work highlights the interplay between evolution of floral longevity and the mating system, with implications for the maintenance of mixed mating in S. angularis.
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Affiliation(s)
- Rachel B. Spigler
- Department of BiologyTemple University1900 N 12th St.PhiladelphiaPA19122USA
| | - Rossana Maguiña
- Department of BiologyTemple University1900 N 12th St.PhiladelphiaPA19122USA
- Present address:
Rossana Maguiña, Ecology and Evolutionary Biology DepartmentUniversity of California Santa Cruz130 McAllister WaySanta CruzCA95060USA
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Xu K, Servedio MR. The evolution of flower longevity in unpredictable pollination environments. J Evol Biol 2021; 34:1781-1792. [PMID: 34536252 DOI: 10.1111/jeb.13936] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 08/31/2021] [Accepted: 09/13/2021] [Indexed: 11/29/2022]
Abstract
Pollination requires a flower to remain open for long enough to allow for the arrival of pollinators. However, maintaining flowers costs energy and resources. Therefore, flower longevity, the length of time a flower remains viable, is critical for the outcome of plant reproduction. Although previous studies showed that the evolution of flower longevity depends on the rates of pollen deposition and removal, whether plants should increase or decrease flower life span when the pollination environment is unpredictable has not been explored. Moreover, the common hypothesis that an unpredictable pollination environment should select for increased flower longevity may be too simplistic since there is no distinction drawn between the effects of spatial and temporal variation. Adopting evolutionary game theory, we investigate the evolution of flower longevity under three types of variation: spatial heterogeneity, daily fluctuations within a flowering season and yearly fluctuations between flowering seasons. We find that spatial heterogeneity often selects for a shorter flower lifespan, while temporal fluctuations of fitness accrual rates at both daily and yearly time scales tends to favour greater longevity, although daily and yearly fluctuations have somewhat different effects. However, the presence of correlation between female and male fitness accrual rates seems to have no effect on flower longevity. Our work suggests that explicit measurements of spatial and temporal variation in both female and male functions may provide a better understanding of the evolution of flower longevity and reproduction.
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Affiliation(s)
- Kuangyi Xu
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Maria R Servedio
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina, USA
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Tang M, Zhao W, Xing M, Zhao J, Jiang Z, You J, Ni B, Ni Y, Liu C, Li J, Chen X. Resource allocation strategies among vegetative growth, sexual reproduction, asexual reproduction and defense during growing season of Aconitum kusnezoffii Reichb. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:957-977. [PMID: 33180340 DOI: 10.1111/tpj.15080] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 09/28/2020] [Accepted: 10/13/2020] [Indexed: 06/11/2023]
Abstract
Natural plants must actively allocate their limited resources for survival and reproduction. Although vegetative growth, sexual reproduction, asexual reproduction and defense are all basic processes in the life cycle of plants, the strategies used to allocate resources between these processes are poorly understood. These processes are conspicuous in naturally grown Aconitum kusnezoffii Reichb., which makes it a suitable study subject. Here, the morphology, dry matter, total organic carbon, total nitrogen and aconitum alkaloid levels of shoot, principal root (PR) and lateral roots were measured throughout the growing season. Then, transcriptome and metabolite content analyses were performed. We found that vegetative growth began first. After vegetative growth ceased, sexual development began. Flower organ development was accompanied by increased photosynthesis and the PR consumed temporarily stored resources after flower formation. Asexual propagule development initiated earlier than sexual reproduction and kept accumulating resources after that. Development was slow before flower formation, mainly manifesting as increasing length; then, after flower formation it accelerated via enhanced material transport and accumulation. Defense compounds were maintained at low levels before flowering. In particular, the turnover of defense compounds was enhanced before and after flower bud emergence, providing resources for other processes. After flower formation, defense compounds were accumulated. The pattern found herein provides a vivid example for further studies on resource allocation strategies. The exciting finding that the PR, as a more direct storage site for photosynthate, is a buffer unit for resources, and that defense compounds can be reused for other processes, suggests a need to explore potential mechanisms.
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Affiliation(s)
- Mingze Tang
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Wei Zhao
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Ming Xing
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Jiaxin Zhao
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Zhang Jiang
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Jian You
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Biao Ni
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Yuanbo Ni
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Chengbai Liu
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Jiangnan Li
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Xia Chen
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
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8
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Zhao Z, Hou M, Wang Y, Du G. Phenological variation of flower longevity and duration of sex phases in a protandrous alpine plant: potential causes and fitness significance. BMC PLANT BIOLOGY 2020; 20:137. [PMID: 32245411 PMCID: PMC7118941 DOI: 10.1186/s12870-020-02356-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Flower longevity plays an important role in pollen dispersal and reproductive success in plants. In dichogamous plants, the duration of anthesis as well as the time allocated to male and female functions can vary in response to intrinsic factors (e.g., flowering time and resource allocation) and pollination context along a growth season. However, the fitness consequences of phenological dynamics have rarely been examined. This study aims to unravel the potential causes driving variation in flower longevity, duration of sex phases, and phenotypic sex during a flowering season of strongly protandrous Aconitum gymnandrum, and particularly reproductive consequences of the phenological pattern. RESULTS Population floral sex ratio shifted from completely male at the beginning to completely female at the end of the season, as is common in other protandrous plants. Phenological dynamics of the floral sex ratio and the duration of sex phases caused a shift from femaleness to maleness in the mean phenotypic sex over the whole season. Floral longevity was negatively correlated with flower size and positively affected by temperature. Early flowers within inflorescences rather than early-flowering individuals emphasized the duration of female over male phase. Owing to the dominance of male-phase flowers, early flowering for individual flowers and plants, or female-biased sex resulted in higher pollen deposition per flower and seed set. At the flower level, flower longevity positively affected female reproductive success, while the effect of flower size was negative. By contrast, plant-level female reproductive success was negatively affected by flower longevity but positively correlated to flower size. CONCLUSIONS The major result of this study lies in elucidating the relationship between variation in phenological sex expression and floral longevity and their fitness consequences of protandrous A. gymnandrum. The contrasting results on female fitness for individual flowers and plants contribute to our current understanding of the adaptive significance of floral longevity.
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Affiliation(s)
- Zhigang Zhao
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000 China
| | - Meng Hou
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000 China
| | - Yijie Wang
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000 China
| | - Guozhen Du
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000 China
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Harder LD, Strelin MM, Clocher IC, Kulbaba MW, Aizen MA. The dynamic mosaic phenotypes of flowering plants. THE NEW PHYTOLOGIST 2019; 224:1021-1034. [PMID: 31087328 DOI: 10.1111/nph.15916] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 05/08/2019] [Indexed: 06/09/2023]
Abstract
Ecological interaction and adaptation both depend on phenotypic characteristics. In contrast with the common conception of the 'adult' phenotype, plant bodies develop continuously during their lives. Furthermore, the different units (metamers) that comprise plant bodies are not identical copies, but vary extensively within individuals. These characteristics foster recognition of plant phenotypes as dynamic mosaics. We elaborate this conception based largely on a wide-ranging review of developmental, ecological and evolutionary studies of plant reproduction, and identify its utility in the analysis of plant form, function and diversification. An expanded phenotypic conception is warranted because dynamic mosaic features affect plant performance and evolve. Evidence demonstrates that dynamic mosaic phenotypes enable functional ontogeny, division of labour, resource and mating efficiency. In addition, dynamic mosaic features differ between individuals and experience phenotypic selection. Investigation of the characteristics and roles of dynamic and mosaic features of plant phenotypes benefits from considering within-individual variation as a function-valued trait that can be analysed with functional data methods. Phenotypic dynamics and within-individual variation arise despite an individual's genetic uniformity, and develop largely by heterogeneous gene expression and associated hormonal control. These characteristics can be heritable, so that dynamic mosaic phenotypes can evolve and diversify by natural selection.
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Affiliation(s)
- Lawrence D Harder
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Marina M Strelin
- Grupo de Ecología de la Polinización, INIBIOMA, CONICET-Universidad Nacional del Comahue, San Carlos de Bariloche, Río Negro, 8400, Argentina
- Universidad Nacional Autónoma de México, Instituto de Ecología, Ciudad de México, 04510, México
| | - Ilona C Clocher
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Mason W Kulbaba
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Marcelo A Aizen
- Grupo de Ecología de la Polinización, INIBIOMA, CONICET-Universidad Nacional del Comahue, San Carlos de Bariloche, Río Negro, 8400, Argentina
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Friedman J, Middleton TE, Rubin MJ. Environmental heterogeneity generates intrapopulation variation in life-history traits in an annual plant. THE NEW PHYTOLOGIST 2019; 224:1171-1183. [PMID: 31400159 DOI: 10.1111/nph.16099] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 08/01/2019] [Indexed: 06/10/2023]
Abstract
Environmental variation affects a plant's life cycle by influencing the timing of germination and flowering, and the duration of the growing season. Yet we know little information about how environmental heterogeneity generates variation in germination schedules and the consequences for growth and fecundity through genetic and plastic responses. We use an annual population of Mimulus guttatus in which, in nature, seeds germinate in both fall and spring. We investigate whether there is a genetic basis to the timing of germination, the effect of germination timing on fecundity, and if growth and flowering respond plastically to compensate for different season lengths. Using sibling families grown in simulated seasonal conditions, we find that families do not differ in their propensity to germinate between seasons. However, the germination season affects subsequent growth and flowering time, with significant genotype-by-environment interactions (G × E). Most G × E is due to unequal variance between seasons, because the spring cohort harbours little genetic variance. Despite their different season lengths, the cohorts do not differ in flower number (fecundity). Heterogeneous environments with unpredictable risks may maintain promiscuous germination, which then affects flowering time. Therefore, if selection at particular life stages changes with climate change, there may be consequences for the entire life cycle.
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Affiliation(s)
- Jannice Friedman
- Department of Biology, Syracuse University, Syracuse, NY, 13244, USA
- Department of Biology, Queen's University, Kingston, ON, K7L 3N6, Canada
| | | | - Matthew J Rubin
- Department of Biology, Syracuse University, Syracuse, NY, 13244, USA
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