1
|
Yue J, Yan Z, Liu W, Liu J, Yang D. A visual pollination mechanism of a new specialized pollinating weevil-plant reciprocity system. FRONTIERS IN PLANT SCIENCE 2024; 15:1432263. [PMID: 39220015 PMCID: PMC11362035 DOI: 10.3389/fpls.2024.1432263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Accepted: 07/29/2024] [Indexed: 09/04/2024]
Abstract
Introduction Pollinating flower-consuming mutualisms are considered exemplary models for studying coevolution due to their rarity. Visual cues are considered to have a major role in facilitating the evolution of floral patterns in these systems. We present a new specialized pollinating flower-consuming mutualism from the plant Wurfbainia villosa, which is a traditional Chinese herbal medicine, by a pollinating weevil, Xenysmoderes sp. Methods In this study, We utilized monochrome plates for binary-choice tests to determine weevil color preferences, conducted behavioral choice experiments, using trackballs, photographed flowers and weevils, and employed blue sticky boards to attract weevils in the field. Results Tests were conducted using colorpreferring weevils in both indoor and outdoor field systems, and validation experiments were performed. Behavioral tests were conducted to investigate the role of the visual cues in the pollinator attraction of W. villosa, which is a selfcompatible insect-pollinated plant that relies primarily on the Xenysmoderes sp. weevil for pollination due to its specialized gynandrium-like structure. Behavioral tests demonstrated that a blue color wavelength of 480 nm and the blue color system, as along with the UV-style pattern of the flowers, particularly the parts with specialized gynandrium-like structures in the labellum, were significantly attractive to both male and female weevils. These results were further confirmed through the field blue sticky board trap method. Discussion These findings indicated that the interaction between W. villosa and Xenysmoderes sp. weevil was a novel symbiotic relationship involving pollinator flower consumption. Additionally, Wurfbainia villosa flowers developed specific visual cues of UV patterns and specialized structures that played a crucial role in attracting pollinators.
Collapse
Affiliation(s)
- Jianjun Yue
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
- School of Traditional Dai-Thai Medicine, West Yunnan University of Applied Sciences, Jinghong, China
| | - Zhen Yan
- Yunnan Key Laboratory of Southern Medicine Utilization, Institute of Medicinal Plant Development Yunnan Branch, Chinese Academy of Medical Sciences and Peking Union Medical College, Jinghong, China
| | - Wei Liu
- School of Traditional Dai-Thai Medicine, West Yunnan University of Applied Sciences, Jinghong, China
| | - Ju Liu
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Depo Yang
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
| |
Collapse
|
2
|
Qin H, Yi X. Mast seeding is stronger in taller plants. FRONTIERS IN PLANT SCIENCE 2024; 15:1382824. [PMID: 39045592 PMCID: PMC11264343 DOI: 10.3389/fpls.2024.1382824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 06/11/2024] [Indexed: 07/25/2024]
Abstract
Introduction Two economies of scale, predator satiation and pollination efficiency, have been proposed to explain the evolutionary mechanisms of mast seeding adopted by some long-lived plants. Plant height is strongly selected by pollination vectors and may also provide economies of scale; however, it remains unknown whether there is a close relationship between adult plant height and mast seeding intensity. Methods Here, we analyzed mast seeding intensity of 158 plant species to test if adult plant height can select for mast seeding. Results We show that mast seeding intensities are higher in taller plant species irrespective of phylogeny, life form, pollination vector, and type of Spermatophytes. We also show that anemophily rather than entomophily selects for taller plant species and higher mast seeding intensities. Discussion The linear correlations and evolutionary links between adult plant height and mast seeding intensity provide evidence that mast seeding could have evolved as an adaptation to taller strategy of perennial plant species.
Collapse
|
3
|
Schroeder H, Salzberg A, Grab H, Crowther S, Hale C, Poveda K. Agricultural landscape simplification affects wild plant reproduction indirectly through herbivore-mediated changes in floral display. Sci Rep 2024; 14:14293. [PMID: 38906942 PMCID: PMC11192729 DOI: 10.1038/s41598-024-65352-2] [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: 03/22/2024] [Accepted: 06/19/2024] [Indexed: 06/23/2024] Open
Abstract
As natural landscapes are modified and converted into simplified agricultural landscapes, the community composition and interactions of organisms persisting in these modified landscapes are altered. While many studies examine the consequences of these changing interactions for crops, few have evaluated the effects on wild plants. Here, we examine how pollinator and herbivore interactions affect reproductive success for wild resident and phytometer plants at sites along a landscape gradient ranging from natural to highly simplified. We tested the direct and indirect effects of landscape composition on plant traits and reproduction mediated by insect interactions. For phytometer plants exposed to herbivores, we found that greater landscape complexity corresponded with elevated herbivore damage, which reduced total flower production but increased individual flower size. Though larger flowers increased pollination, the reduction in flowers ultimately reduced plant reproductive success. Herbivory was also higher in complex landscapes for resident plants, but overall damage was low and therefore did not have a cascading effect on floral display and reproduction. This work highlights that landscape composition directly affects patterns of herbivory with cascading effects on pollination and wild plant reproduction. Further, the absence of an effect on reproduction for resident plants suggests that they may be adapted to their local insect community.
Collapse
Affiliation(s)
| | - Annika Salzberg
- Department of Entomology, Cornell University, Ithaca, NY, USA
| | - Heather Grab
- School of Integrative Plant Sciences, Cornell University, Ithaca, NY, USA
| | - Shea Crowther
- Department of Entomology, Cornell University, Ithaca, NY, USA
| | - Casey Hale
- Department of Entomology, Cornell University, Ithaca, NY, USA
| | - Katja Poveda
- Department of Entomology, Cornell University, Ithaca, NY, USA
| |
Collapse
|
4
|
Ito Y, Kudo G. The contribution of carbon budget to masting intervals in Veratrum album populations inhabiting different elevations. AMERICAN JOURNAL OF BOTANY 2024; 111:e16295. [PMID: 38403896 DOI: 10.1002/ajb2.16295] [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: 06/14/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 02/27/2024]
Abstract
PREMISE Mast flowering/seeding is often more extreme in lower-resource environments, such as alpine compared to lowland habitats. We studied a masting herb that had less extreme masting at higher elevations, and tested if this difference could be explained by higher photosynthetic productivity and/or lower reproductive investment at the higher-elevation sites. METHODS We examined the relationship between flowering intervals and carbon budget (i.e., the balance between reproductive investment and annual carbon fixation) in a masting herb, Veratrum album subsp. oxysepalum, across five lowland and six alpine populations in northern Japan. We evaluated the previous flowering histories of individual plants based on rhizome morphology and analyzed the masting patterns of individual populations. Total mass of the reproductive organs, as a proxy of reproductive investment, was compared between the lowland and alpine populations. Annual carbon fixation was estimated on the basis of photosynthetic capacity, total leaf area per plant, and seasonal transition of light availability. RESULTS Interval between high-flowering years was shorter and total reproductive investment was smaller in the alpine than in the lowland populations. Owing to its high photosynthetic capacity and continuous bright conditions, annual carbon fixation per plant was 1.5 times greater in alpine habitat than in lowland habitat. These results suggest that V. album alpine populations have shorter flowering intervals than lowland populations due to faster recovery from energy loss after reproduction. CONCLUSIONS Our study demonstrated that masting intervals in V. album populations can be explained by habitat-specific carbon budget balances.
Collapse
Affiliation(s)
- Yohei Ito
- Graduate School of Environmental Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - Gaku Kudo
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, 060-0810, Japan
| |
Collapse
|
5
|
Pedraza F, Liu H, Gawecka KA, Bascompte J. The Role of Indirect Effects in Coevolution along the Mutualism-Antagonism Continuum. Am Nat 2024; 203:28-42. [PMID: 38207144 DOI: 10.1086/727472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
AbstractThe web of interactions in a community drives the coevolution of species. Yet it is unclear how the outcome of species interactions influences the coevolutionary dynamics of communities. This is a pressing matter, as changes to the outcome of interactions may become more common with human-induced global change. Here, we combine network and evolutionary theory to explore coevolutionary outcomes in communities harboring mutualistic and antagonistic interactions. We show that as the ratio of mutualistic to antagonistic interactions decreases, selection imposed by direct partners outweighs that imposed by indirect partners. This weakening of indirect effects results in communities composed of species with dissimilar traits and fast rates of adaptation. These changes are more pronounced when specialist consumers are the first species to engage in antagonistic interactions. Hence, a shift in the outcome of species interactions may reverberate across communities and alter the direction and speed of coevolution.
Collapse
|
6
|
Chen KH, Pannell JR. Unisexual flowers as a resolution to intralocus sexual conflict in hermaphrodites. Proc Biol Sci 2023; 290:20232137. [PMID: 38018108 PMCID: PMC10685137 DOI: 10.1098/rspb.2023.2137] [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: 09/19/2023] [Accepted: 11/01/2023] [Indexed: 11/30/2023] Open
Abstract
In dioecious populations, males and females may evolve different trait values to increase fitness through their respective sexual functions. Because hermaphrodites express both sexual functions, resolving sexual conflict is potentially more difficult for them. Here, we show that hermaphrodite plants can partially resolve sexual conflict by expressing different trait values in different male and female modules (e.g. different flowers, inflorescences, branches etc.). We analysed the flowering phenology, sex allocation and selection gradients on floral traits of flowers of the andromonoecious plant Pulsatilla alpina, which produces both bisexual and male flowers. Our results indicate that strong protogyny prevents early bisexual flowers from profiting from high siring opportunities early in the reproductive season at a time when male flowers could achieve high siring success. The production of unisexual male flowers thus resolves this sexual conflict because it allows the flowers to express their male function without waiting until after the female function has been performed. Our study illustrates the resolution of sexual conflict arising from phenological constraints via modular divergence in sex allocation. We discuss the extent to which modular variation in sex allocation in the context of other sexual systems may be similarly explained.
Collapse
Affiliation(s)
- Kai-Hsiu Chen
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
| | - John R. Pannell
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
| |
Collapse
|
7
|
Gómez JM, González-Megías A, Armas C, Narbona E, Navarro L, Perfectti F. The role of phenotypic plasticity in shaping ecological networks. Ecol Lett 2023; 26 Suppl 1:S47-S61. [PMID: 37840020 DOI: 10.1111/ele.14192] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 01/16/2023] [Accepted: 02/15/2023] [Indexed: 10/17/2023]
Abstract
Plasticity-mediated changes in interaction dynamics and structure may scale up and affect the ecological network in which the plastic species are embedded. Despite their potential relevance for understanding the effects of plasticity on ecological communities, these effects have seldom been analysed. We argue here that, by boosting the magnitude of intra-individual phenotypic variation, plasticity may have three possible direct effects on the interactions that the plastic species maintains with other species in the community: may expand the interaction niche, may cause a shift from one interaction niche to another or may even cause the colonization of a new niche. The combined action of these three factors can scale to the community level and eventually expresses itself as a modification in the topology and functionality of the entire ecological network. We propose that this causal pathway can be more widespread than previously thought and may explain how interaction niches evolve quickly in response to rapid changes in environmental conditions. The implication of this idea is not solely eco-evolutionary but may also help to understand how ecological interactions rewire and evolve in response to global change.
Collapse
Affiliation(s)
- José M Gómez
- Estación Experimental de Zonas Áridas (EEZA-CSIC), Almería, Spain
- Research Unit Modeling Nature, Universidad de Granada, Granada, Spain
| | - Adela González-Megías
- Research Unit Modeling Nature, Universidad de Granada, Granada, Spain
- Departamento de Zoología, Universidad de Granada, Granada, Spain
| | - Cristina Armas
- Estación Experimental de Zonas Áridas (EEZA-CSIC), Almería, Spain
| | - Eduardo Narbona
- Departamento de Biología Molecular e Ingeniería Bioquímica, Universidad Pablo de Olavide, Sevilla, Spain
| | - Luis Navarro
- Departamento de Biología Vegetal y Ciencias del Suelo, Universidad de Vigo, Vigo, Spain
| | - Francisco Perfectti
- Research Unit Modeling Nature, Universidad de Granada, Granada, Spain
- Departamento de Genética, Universidad de Granada, Granada, Spain
| |
Collapse
|
8
|
Das S, Das A. Ants are more than just curious bystanders to some flowers-they act as significant pollinators. FRONTIERS IN INSECT SCIENCE 2023; 3:1145761. [PMID: 38469491 PMCID: PMC10926462 DOI: 10.3389/finsc.2023.1145761] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 05/25/2023] [Indexed: 03/13/2024]
Abstract
Ant-plant associations are ubiquitous and highly diverse in almost all terrestrial environments, resulting in complex ecological networks. Although ant-plant mutualism is prevalent, ant-mediated pollination is uncommon, and only a few investigations have demonstrated their role in pollination. Thus, the topic of ant-mediated pollination requires revision to assess its significance in pollination biology. Ants are frequent floral visitors, but their impact on plant reproductive fitness is rarely acknowledged; nonetheless, numerous flower-visiting ants have been investigated for their involvement in promoting floral development and hybrid vigor in crops. In this study, we present a summary of the scientific literature published over the last four decades on ants' involvement in pollination, the diversity of pollinating ants to various host plants, the ant-plant pollinating networks, and seasonal patterns of ant-mediated pollination. Ants generally forage for flowers in quest of nectar and other sustenance, and in doing so they pollinate the flowers that they encounter. This review identified the pollination networks between ants and plants at the species and family levels. Pollination is often affected by a number of aspects, including the flower's sex, its ovary position, the inflorescence it bears, and the time of year. The available literature demonstrates that ants visit the inflorescences of the same species only to promote cross-pollination, a process known as "geitonogamy"; however, we conclude that ants may visit different inflorescences of different plants in the field. If ant pollination is the norm, there is less selection pressure to acquire self-compatibility; nonetheless, ants' cross-pollination may have caused ants to co-evolve with the pollinating flowers. This indicates that ants are more than just curious bystanders to some flowers; they act as significant pollinators.
Collapse
Affiliation(s)
| | - Amlan Das
- Entomology Laboratory, Department of Zoology, University of Calcutta, Kolkata, West Bengal, India
| |
Collapse
|
9
|
Schroeder H, Grab H, Poveda K. Phenotypic clines in herbivore resistance and reproductive traits in wild plants along an agricultural gradient. PLoS One 2023; 18:e0286050. [PMID: 37256895 DOI: 10.1371/journal.pone.0286050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 05/08/2023] [Indexed: 06/02/2023] Open
Abstract
The conversion of natural landscapes to agriculture is a leading cause of biodiversity loss worldwide. While many studies examine how landscape modification affects species diversity, a trait-based approach can provide new insights into species responses to environmental change. Wild plants persisting in heavily modified landscapes provide a unique opportunity to examine species' responses to land use change. Trait expression within a community plays an important role in structuring species interactions, highlighting the potential implications of landscape mediated trait changes on ecosystem functioning. Here we test the effect of increasing agricultural landscape modification on defensive and reproductive traits in three commonly occurring Brassicaceae species to evaluate plant responses to landscape change. We collected seeds from populations at spatially separated sites with variation in surrounding agricultural land cover and grew them in a greenhouse common garden, measuring defensive traits through an herbivore no-choice bioassay as well as reproductive traits such as flower size and seed set. In two of the three species, plants originating from agriculturally dominant landscapes expressed a consistent reduction in flower size and herbivore leaf consumption. One species also showed reduced fitness associated with increasingly agricultural landscapes. These findings demonstrate that wild plants are responding to landscape modification, suggesting that the conversion of natural landscapes to agriculture has consequences for wild plant evolution.
Collapse
Affiliation(s)
- Hayley Schroeder
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
| | - Heather Grab
- School of Integrative Plant Sciences, Cornell University, Ithaca, New York, United States of America
| | - Katja Poveda
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
| |
Collapse
|
10
|
Wu Y, Liu G, Sletvold N, Duan X, Tong Z, Li Q. Soil water and nutrient availability interactively modify pollinator-mediated directional and correlational selection on floral display. THE NEW PHYTOLOGIST 2023; 237:672-683. [PMID: 36229922 DOI: 10.1111/nph.18537] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
The individual and combined effects of abiotic factors on pollinator-mediated selection on floral traits are not well documented. To examine potential interactive effects of water and nutrient availability on pollinator-mediated selection on three floral display traits of Primula tibetica, we manipulated pollination and nutrient availability in a factorial experiment, conducted at two common garden sites with different soil water content (natural vs addition). We found that both water and nutrient availability affected floral trait expression in P. tibetica and that hand pollination increased seed production most when both nutrient content and water content were high, indicating joint pollen and resource limitation. We documented selection on all floral traits, and pollinators contributed to directional and correlational selection on plant height and number of flowers. Soil water and nutrient availability interactively influenced the strength of both pollinator-mediated directional and correlational selection, with significant selection observed when nutrient or water availability was high, but not when none or both were added. The results suggest that resource limitation constrains the response of P. tibetica to among-individual variation in pollen receipt, that addition of nutrients or water leads to pollinator-mediated selection and that effects of the two abiotic factors are nonadditive.
Collapse
Affiliation(s)
- Yun Wu
- School of Architecture and Civil Engineering, Xihua University, Chengdu, 610039, China
| | - Guangli Liu
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, 611130, China
| | - Nina Sletvold
- Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36, Uppsala, Sweden
| | - Xuyu Duan
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, 611130, China
| | - Zhaoli Tong
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, 650091, China
- Laboratory of Ecology and Evolutionary Biology, School of Ecology and Environmental Science, Yunnan University, Kunming, 650091, China
| | - Qingjun Li
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, 650091, China
- Laboratory of Ecology and Evolutionary Biology, School of Ecology and Environmental Science, Yunnan University, Kunming, 650091, China
| |
Collapse
|
11
|
Koski MH. Pollinators exert selection on floral traits in a pollen-limited, narrowly endemic spring ephemeral. AMERICAN JOURNAL OF BOTANY 2023; 110:e16101. [PMID: 36371765 PMCID: PMC10108127 DOI: 10.1002/ajb2.16101] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 10/27/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
PREMISE Floral traits are frequently under pollinator-mediated selection, especially in taxa subject to strong pollen-limitation, such as those reliant on pollinators. However, antagonists can be agents of selection on floral traits as well. The causes of selection acting on spring ephemerals are understudied though these species can experience particularly strong pollen-limitation. I examined pollinator- and antagonist-mediated selection in a narrowly endemic spring ephemeral, Trillium discolor. METHODS I measured pollen limitation in T. discolor across two years and evaluated its breeding system. I compared selection on floral traits (display height, petal size, petal color, flowering time) between open-pollinated, and pollen-supplemented plants to measure the strength and mode of pollinator-mediated selection. I assessed whether natural levels of antagonism impacted selection on floral traits. RESULTS Trillium discolor was self-incompatible and experienced pollen limitation in both years of the study. Pollinators exerted negative disruptive selection on display height and petals size. In one year, pollinator-mediated selection favored lighter petals but in the second year pollinators favored darker petals. Antagonist damage did not alter selection on floral traits. CONCLUSIONS Results demonstrate that pollinators mediate the strength and mode of selection on floral traits in T. discolor. Interannual variation in the strength, mode, and direction of pollinator-mediated selection on floral traits could be important for maintaining of floral diversity in this system. Observed levels of antagonism were weak agents of selection on floral traits.
Collapse
Affiliation(s)
- Matthew H. Koski
- Department of Biological SciencesClemson UniversityClemsonSouth Carolina29634USA
| |
Collapse
|
12
|
Chen K, Pannell JR. Disruptive selection via pollinators and seed predators on the height of flowers on a wind-dispersed alpine herb. AMERICAN JOURNAL OF BOTANY 2022; 109:1717-1729. [PMID: 36194694 PMCID: PMC9828390 DOI: 10.1002/ajb2.16073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 06/28/2022] [Indexed: 05/25/2023]
Abstract
PREMISE Floral stalk height is known to affect seed dispersal of wind-dispersed grassland species, but it may also affect the attractiveness of flowers and fruits of animal-pollinated and animal-dispersed plants. Stalk height may thus be responsive to selection via interactions with both mutualist pollinators and seed dispersers, but also antagonist florivores and seed predators. In this study, we aimed to determine the effect of pollinators and seed predators on selection on floral stalk height in the insect-pollinated and wind-dispersed, alpine, andromonoecious herb Pulsatilla alpina, whose flowers also vary in their sex allocation and thus in the resources available to both mutualists and antagonists. METHODS We measured the resource status of individuals in terms of their size and the height of the vegetation surrounding plants of P. alpina at 11 sites. In one population, we recorded floral stalk height over an entire growing season and investigated its association with floral morphology and floral sex allocation (pistil and stamen number) and used leaf-removal manipulations to assess the effect of herbivory on floral stalk height. Finally, in four populations, we quantified phenotypic selection on floral stalk height in four female components of reproductive success before seed dispersal. RESULTS Stalk height was positively associated with female allocation of the respective flower, the resource status of the individual, and the height of the surrounding vegetation, and negatively affected by leaf removal. Our results point to disruptive selection on stalk height in terms of both selection differentials and selection gradients for fertilization, seed predation, and seed maturation rates and to positive selection on stalk height in terms of a selection differential for mature seed number. CONCLUSIONS Stalk height of P. alpina is a costly trait that affects female reproductive success via interactions with both mutualists and antagonists. We discuss the interplay between the resource status and selection imposed on female reproductive success and its likely role in the evolution of sex-allocation strategies, especially andromonoecy.
Collapse
Affiliation(s)
- Kai‐Hsiu Chen
- Department of Ecology and EvolutionUniversity of LausanneBiophore Building1015LausanneSwitzerland
| | - John R. Pannell
- Department of Ecology and EvolutionUniversity of LausanneBiophore Building1015LausanneSwitzerland
| |
Collapse
|
13
|
Schroeder H. Digest: Extensive pollinator sharing does not promote character displacement in two orchid congeners. Evolution 2022; 76:1652-1653. [PMID: 35661154 DOI: 10.1111/evo.14537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/12/2022] [Indexed: 01/22/2023]
Abstract
The sharing of pollinators between closely related plant species may be detrimental to plant reproductive success. This predicts that natural selection should favor divergent traits that facilitate coexistence by niche partitioning. Testing this hypothesis in mixed versus pure sites of two pollinator-sharing orchid species, Joffard et al. found that one species had a shift in the timing of floral scent emission that did not match the shift in pollinator visitation. This raises further questions about the mechanisms driving floral trait evolution.
Collapse
|
14
|
Carlson ML, Fulkerson JR. Phenotypic selection on floral traits in the arctic plant
Parrya nudicaulis
(Brassicaceae). Ecol Evol 2022; 12:e8624. [PMID: 35261739 PMCID: PMC8888260 DOI: 10.1002/ece3.8624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 10/20/2021] [Accepted: 10/29/2021] [Indexed: 11/06/2022] Open
Abstract
The evolution of floral traits is often attributed to pollinator‐mediated selection; however, the importance of pollinators as selective agents in arctic environments is poorly resolved. In arctic and subarctic regions that are thought to be pollen limited, selection is expected to either favor floral traits that increase pollinator attraction or promote reproductive assurance through selfing. We quantified phenotypic selection on floral traits in two arctic and two subarctic populations of the self‐compatible, but largely pollinator‐dependent, Parrya nudicaulis. Additionally, we measured selection in plants in both open pollination and pollen augmentation treatments to estimate selection imposed by pollinators in one population. Seed production was found to be limited by pollen availability and strong directional selection on flower number was observed. We did not detect consistently greater magnitudes of selection on floral traits in the arctic relative to the subarctic populations. Directional selection for more pigmented flowers in one arctic population was observed, however. In some populations, selection on flower color was found to interact with other traits. We did not detect consistently stronger selection gradients across all traits for plants exposed to pollinator selection relative to those in the pollen augmentation treatment; however, directional selection tended to be higher for some floral traits in open‐pollinated plants.
Collapse
Affiliation(s)
- Matthew L. Carlson
- Alaska Center for Conservation Science University of Alaska Anchorage Anchorage Alaska USA
- Biological Sciences Department University of Alaska Anchorage Anchorage Alaska USA
| | - Justin R. Fulkerson
- Alaska Center for Conservation Science University of Alaska Anchorage Anchorage Alaska USA
- Biological Sciences Department University of Alaska Anchorage Anchorage Alaska USA
| |
Collapse
|
15
|
Yacine Y, Loeuille N. Stable coexistence in plant-pollinator-herbivore communities requires balanced mutualistic vs antagonistic interactions. Ecol Modell 2022. [DOI: 10.1016/j.ecolmodel.2021.109857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
16
|
Cabin Z, Derieg NJ, Garton A, Ngo T, Quezada A, Gasseholm C, Simon M, Hodges SA. Non-pollinator selection for a floral homeotic mutant conferring loss of nectar reward in Aquilegia coerulea. Curr Biol 2022; 32:1332-1341.e5. [PMID: 35176226 DOI: 10.1016/j.cub.2022.01.066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 11/12/2021] [Accepted: 01/21/2022] [Indexed: 12/12/2022]
Abstract
Here, we describe a polymorphic population of Aquilegia coerulea with a naturally occurring floral homeotic mutant, A. coerulea var. daileyae, where the characteristic petals with nectar spurs are replaced with a second set of sepals. Although it would be expected that this loss of pollinator reward would be disadvantageous to the mutant, we find that it has reached relatively high frequency (∼25%) and is under strong, positive selection across multiple seasons (s = 0.17-0.3) primarily due to reduced floral herbivory. We identify the underlying locus (APETALA3-3) and multiple causal loss-of-function mutations indicating an ongoing soft sweep. Elevated linkage disequilibrium around the two most common causal alleles indicates that positive selection has been occurring for many generations. Lastly, genotypic frequencies at AqAP3-3 indicate a degree of positive assortative mating by morphology. Together, these data provide both a compelling example that large-scale discontinuous morphological changes differentiating taxa can occur due to single mutations and a particularly clear example of linking genotype, phenotype, and fitness.
Collapse
Affiliation(s)
- Zachary Cabin
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
| | - Nathan J Derieg
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Alexandra Garton
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Timothy Ngo
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Ashley Quezada
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Constantine Gasseholm
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Mark Simon
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Scott A Hodges
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
| |
Collapse
|
17
|
Wu Y, Barrett SCH, Duan X, Zhang J, Cha Y, Tu C, Li Q. Herbivore-Mediated Selection on Floral Display Covaries Nonlinearly With Plant-Antagonistic Interaction Intensity Among Primrose Populations. FRONTIERS IN PLANT SCIENCE 2021; 12:727957. [PMID: 34868113 PMCID: PMC8636000 DOI: 10.3389/fpls.2021.727957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
Quantifying the relations between plant-antagonistic interactions and natural selection among populations is important for predicting how spatial variation in ecological interactions drive adaptive differentiation. Here, we investigate the relations between the opportunity for selection, herbivore-mediated selection, and the intensity of plant-herbivore interaction among 11 populations of the insect-pollinated plant Primula florindae over 2 years. We experimentally quantified herbivore-mediated directional selection on three floral traits (two display and one phenological) within populations and found evidence for herbivore-mediated selection for a later flowering start date and a greater number of flowers per plant. The opportunity for selection and strength of herbivore-mediated selection on number of flowers varied nonlinearly with the intensity of herbivory among populations. These parameters increased and then decreased with increasing intensity of plant-herbivore interactions, defined as an increase in the ratio of herbivore-damaged flowers per individual. Our results provide novel insights into how plant-antagonistic interactions can shape spatial variation in selection on floral traits and contribute toward understanding the mechanistic basis of geographic variation in angiosperm flowers.
Collapse
Affiliation(s)
- Yun Wu
- School of Civil Engineering, Architecture and Environment, Xihua University, Chengdu, China
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, School of Ecology and Environmental Science, Yunnan University, Kunming, China
| | - Spencer C. H. Barrett
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - Xuyu Duan
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Jie Zhang
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, School of Ecology and Environmental Science, Yunnan University, Kunming, China
| | - Yongpeng Cha
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, School of Ecology and Environmental Science, Yunnan University, Kunming, China
| | - Chengyi Tu
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, School of Ecology and Environmental Science, Yunnan University, Kunming, China
| | - Qingjun Li
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, School of Ecology and Environmental Science, Yunnan University, Kunming, China
| |
Collapse
|
18
|
Knauer AC, Kokko H, Schiestl FP. Pollinator behaviour and resource limitation maintain honest floral signalling. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Anina C. Knauer
- Department of Systematic and Evolutionary Botany University of Zurich Zürich Switzerland
| | - Hanna Kokko
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zürich Switzerland
| | - Florian P. Schiestl
- Department of Systematic and Evolutionary Botany University of Zurich Zürich Switzerland
| |
Collapse
|
19
|
Lu NN, Ma Y, Hou M, Zhao ZG. The function of floral traits and phenotypic selection in Aconitum gymnandrum (Ranunculaceae). PLANT BIOLOGY (STUTTGART, GERMANY) 2021; 23:931-938. [PMID: 34396652 DOI: 10.1111/plb.13305] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/07/2021] [Indexed: 06/13/2023]
Abstract
Floral evolution in angiosperms is thought to be driven by pollinator-mediated selection. Understanding flower integration and adaptation requires resolving the additive and nonadditive contributions of floral pollinator attraction and pollination efficiency traits to fitness components. In this study, a flower manipulation experiment with a factorial design was used to study the adaptive significance of galea height (a putative attraction trait) and entrance width (a putative efficiency trait) in Aconitum gymnandrum Maxim. flowers. Simultaneously, phenotypic selection analysis was conducted to examine selection by pollinators on galea height, entrance width, nectar production and plant height. Increased galea height increased the pollinator visitation rate, which confirmed its attractiveness function. Increasing floral entrance width by spreading the lower sepals increased the seed number per fruit without affecting pollinator visitation. This suggests a pollination efficiency role for the entrance width. The phenotypic selection analysis, however, did not provide evidence of pollinator-mediated selection for either of these traist, but it did for plant height. According to the manipulation treatment and correlational selection results, the combined variation in galea height and entrance width of A. gymnandrum flowers did not have nonadditive effects on female reproductive success. This study demonstrated the adaptive value of A. gymnandrum flowers through manipulation of an attractiveness trait and an efficiency trait. However, neither trait was associated with pollinator-mediated selection. A combination of manipulating traits and determining current phenotypic selection could help to elucidate the mechanism of selection on floral traits involved in different functions and flower integration.
Collapse
Affiliation(s)
- N-N Lu
- School of Life Science, North-West Normal University, Lanzhou, China
| | - Y Ma
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - M Hou
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Z-G Zhao
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
| |
Collapse
|
20
|
Benoit AD, Caruso CM. A sit-and-wait predator, but not an active-pursuit predator, alters pollinator-mediated selection on floral traits. Ecology 2021; 102:e03506. [PMID: 34319595 DOI: 10.1002/ecy.3506] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 05/12/2021] [Accepted: 05/25/2021] [Indexed: 12/27/2022]
Abstract
Indirect species interactions are ubiquitous in nature, often outnumbering direct species interactions. Yet despite evidence that indirect interactions have strong ecological effects, relatively little is known about whether they can shape adaptive evolution by altering the strength and/or direction of natural selection. We tested whether indirect interactions affect the strength and direction of pollinator-mediated selection on floral traits of the bumble-bee pollinated wildflower Lobelia siphilitica. We estimated the indirect effects of two pollinator predators with contrasting hunting modes: dragonflies (Aeshnidae and Corduliidae) and ambush bugs (Phymata americana, Reduviidae). Because dragonflies are active pursuit predators, we hypothesized that they would strengthen pollinator-mediated selection by weakening plant-pollinator interactions (i.e., a density-mediated indirect effect). In contrast, because ambush bugs are sit-and-wait predators, we hypothesized that they would weaken or reverse the direction of pollinator-mediated selection by altering pollinator foraging behavior (i.e., a trait-mediated indirect effect). Specifically, if ambush bugs hunt from plants with traits that attract pollinators (i.e., prey), then pollinators will spend less time visiting those plants, weakening or reversing the direction of selection on attractive floral traits. We did not find evidence that high dragonfly abundance strengthened selection on floral traits via a density-mediated indirect effect: neither pollen limitation (a proxy for the strength of plant-pollinator interactions) nor directional selection on floral traits of L. siphilitica differed significantly between high- and low-dragonfly abundance treatments. In contrast, we did find evidence that ambush bug presence affected selection on floral traits via a trait-mediated indirect effect: ambush bugs hunted from L. siphilitica plants with larger daily floral displays, reversing the direction of pollinator-mediated selection on daily display size. These results suggest that indirect species interactions have the potential to shape adaptive evolution by altering natural selection.
Collapse
Affiliation(s)
- Amanda D Benoit
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Christina M Caruso
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| |
Collapse
|
21
|
Afkhami ME, Friesen ML, Stinchcombe JR. Multiple Mutualism Effects generate synergistic selection and strengthen fitness alignment in the interaction between legumes, rhizobia and mycorrhizal fungi. Ecol Lett 2021; 24:1824-1834. [PMID: 34110064 DOI: 10.1111/ele.13814] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 05/02/2021] [Indexed: 01/05/2023]
Abstract
Nearly all organisms participate in multiple mutualisms, and complementarity within these complex interactions can result in synergistic fitness effects. However, it remains largely untested how multiple mutualisms impact eco-evolutionary dynamics in interacting species. We tested how multiple microbial mutualists-N-fixing bacteria and mycorrrhizal fungi-affected selection and heritability of traits in their shared host plant (Medicago truncatula), as well as fitness alignment between partners. Our results demonstrate for the first time that multiple mutualisms synergistically affect the selection and heritability of host traits and enhance fitness alignment between mutualists. Specifically, we found interaction with multiple microbial symbionts doubled the strength of natural selection on a plant architectural trait, resulted in 2- to 3-fold higher heritability of plant reproductive success, and more than doubled fitness alignment between N-fixing bacteria and plants. These findings show synergism generated by multiple mutualisms extends to key components of microevolutionary change, emphasising the importance of multiple mutualism effects on evolutionary trajectories.
Collapse
Affiliation(s)
| | - Maren L Friesen
- Department of Plant Pathology, Department of Crop and Soil Sciences, Washington State University, Pullman, WA, USA
| | - John R Stinchcombe
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
22
|
Osuna-Mascaró C, Rubio de Casas R, Landis JB, Perfectti F. Genomic Resources for Erysimum spp. (Brassicaceae): Transcriptome and Chloroplast Genomes. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.620601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
23
|
Schroeder H, Grab H, Kessler A, Poveda K. Human-Mediated Land Use Change Drives Intraspecific Plant Trait Variation. FRONTIERS IN PLANT SCIENCE 2021; 11:592881. [PMID: 33519849 PMCID: PMC7840540 DOI: 10.3389/fpls.2020.592881] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 12/22/2020] [Indexed: 06/02/2023]
Abstract
In the Anthropocene, more than three quarters of ice-free land has experienced some form of human-driven habitat modification, with agriculture dominating 40% of the Earth's surface. This land use change alters the quality, availability, and configuration of habitat resources, affecting the community composition of plants and insects, as well as their interactions with each other. Landscapes dominated by agriculture are known to support a lower abundance and diversity of pollinators and frequently larger populations of key herbivore pests. In turn, insect communities subsidized by agriculture may spill into remaining natural habitats with consequences for wild plants persisting in (semi) natural habitats. Adaptive responses by wild plants may allow them to persist in highly modified landscapes; yet how landscape-mediated variation in insect communities affects wild plant traits related to reproduction and defense remains largely unknown. We synthesize the evidence for plant trait changes across land use gradients and propose potential mechanisms by which landscape-mediated changes in insect communities may be driving these trait changes. Further, we present results from a common garden experiment on three wild Brassica species demonstrating variation in both defensive and reproductive traits along an agricultural land use gradient. Our framework illustrates the potential for plant adaptation under land use change and predicts how defense and reproduction trait expression may shift in low diversity landscapes. We highlight areas of future research into plant population and community effects of land use change.
Collapse
Affiliation(s)
- Hayley Schroeder
- Department of Entomology, Cornell University, Ithaca, NY, United States
| | - Heather Grab
- Department of Entomology, Cornell University, Ithaca, NY, United States
- School of Integrative Plant Sciences, Cornell University, Ithaca, NY, United States
| | - André Kessler
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States
| | - Katja Poveda
- Department of Entomology, Cornell University, Ithaca, NY, United States
| |
Collapse
|
24
|
Abdelaziz M, Muñoz-Pajares AJ, Berbel M, García-Muñoz A, Gómez JM, Perfectti F. Asymmetric Reproductive Barriers and Gene Flow Promote the Rise of a Stable Hybrid Zone in the Mediterranean High Mountain. FRONTIERS IN PLANT SCIENCE 2021; 12:687094. [PMID: 34512685 PMCID: PMC8424041 DOI: 10.3389/fpls.2021.687094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 07/15/2021] [Indexed: 05/13/2023]
Abstract
Hybrid zones have the potential to shed light on evolutionary processes driving adaptation and speciation. Secondary contact hybrid zones are particularly powerful natural systems for studying the interaction between divergent genomes to understand the mode and rate at which reproductive isolation accumulates during speciation. We have studied a total of 720 plants belonging to five populations from two Erysimum (Brassicaceae) species presenting a contact zone in the Sierra Nevada mountains (SE Spain). The plants were phenotyped in 2007 and 2017, and most of them were genotyped the first year using 10 microsatellite markers. Plants coming from natural populations were grown in a common garden to evaluate the reproductive barriers between both species by means of controlled crosses. All the plants used for the field and greenhouse study were characterized by measuring traits related to plant size and flower size. We estimated the genetic molecular variances, the genetic differentiation, and the genetic structure by means of the F-statistic and Bayesian inference. We also estimated the amount of recent gene flow between populations. We found a narrow unimodal hybrid zone where the hybrid genotypes appear to have been maintained by significant levels of a unidirectional gene flow coming from parental populations and from weak reproductive isolation between them. Hybrid plants exhibited intermediate or vigorous phenotypes depending on the analyzed trait. The phenotypic differences between the hybrid and the parental plants were highly coherent between the field and controlled cross experiments and through time. The highly coherent results obtained by combining field, experimental, and genetic data demonstrate the existence of a stable and narrow unimodal hybrid zone between Erysimum mediohispanicum and Erysimum nevadense at the high elevation of the Sierra Nevada mountains.
Collapse
Affiliation(s)
- Mohamed Abdelaziz
- Departamento de Genética, Facultad de Ciencias, Campus Fuentenueva, Universidad de Granada, Granada, Spain
- *Correspondence: Mohamed Abdelaziz
| | - A. Jesús Muñoz-Pajares
- Departamento de Genética, Facultad de Ciencias, Campus Fuentenueva, Universidad de Granada, Granada, Spain
- Laboratório Associado, Plant Biology, Research Centre in Biodiversity and Genetic Resources, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade Do Porto, Campus Agrário de Vairão, Fornelo e Vairão, Portugal
- Research Unit Modeling Nature, Universidad de Granada, Granada, Spain
| | - Modesto Berbel
- Departamento de Genética, Facultad de Ciencias, Campus Fuentenueva, Universidad de Granada, Granada, Spain
| | - Ana García-Muñoz
- Departamento de Genética, Facultad de Ciencias, Campus Fuentenueva, Universidad de Granada, Granada, Spain
| | - José M. Gómez
- Research Unit Modeling Nature, Universidad de Granada, Granada, Spain
- Departamento de Ecología Funcional y Evolutiva, Estación Experimental de Zonas Áridas, Consejo Superior de Investigaciones Científicas, Almeria, Spain
| | - Francisco Perfectti
- Departamento de Genética, Facultad de Ciencias, Campus Fuentenueva, Universidad de Granada, Granada, Spain
- Research Unit Modeling Nature, Universidad de Granada, Granada, Spain
| |
Collapse
|
25
|
Rodríguez-Castañeda NL, Ortiz PL, Arista M, Narbona E, Buide ML. Indirect Selection on Flower Color in Silene littorea. FRONTIERS IN PLANT SCIENCE 2020; 11:588383. [PMID: 33424884 PMCID: PMC7785944 DOI: 10.3389/fpls.2020.588383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 11/25/2020] [Indexed: 05/07/2023]
Abstract
Flower color, as other floral traits, may suffer conflicting selective pressures mediated by both mutualists and antagonists. The maintenance of intraspecific flower color variability has been usually explained as a result of direct selection by biotic agents. However, flower color might also be under indirect selection through correlated traits, since correlations among flower traits are frequent. In this study, we aimed to find out how flower color variability is maintained in two nearby populations of Silene littorea that consistently differ in the proportions of white-flowered plants. To do that, we assessed natural selection on floral color and correlated traits by means of phenotypic selection analysis and path analysis. Strong directional selection on floral display and flower production was found in both populations through either male or female fitness. Flower color had a negative indirect effect on the total male and female fitness in Melide population, as plants with lighter corollas produced more flowers. In contrast, in Barra population, plants with darker corollas produced more flowers and have darker calices, which in turn were selected. Our results suggest that the prevalence of white-flowered plants in Melide and pink-flowered plants in Barra is a result of indirect selection through correlated flower traits and not a result of direct selection of either pollinators or herbivores on color.
Collapse
Affiliation(s)
| | - Pedro L. Ortiz
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Montserrat Arista
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Eduardo Narbona
- Departamento de Biología Molecular e Ingeniería Bioquímica, Universidad Pablo de Olavide, Seville, Spain
| | - Mª Luisa Buide
- Departamento de Biología Molecular e Ingeniería Bioquímica, Universidad Pablo de Olavide, Seville, Spain
| |
Collapse
|
26
|
Zu P, Schiestl FP, Gervasi D, Li X, Runcie D, Guillaume F. Floral signals evolve in a predictable way under artificial and pollinator selection in Brassica rapa. BMC Evol Biol 2020; 20:127. [PMID: 32972368 PMCID: PMC7517814 DOI: 10.1186/s12862-020-01692-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 09/16/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Angiosperms employ an astonishing variety of visual and olfactory floral signals that are generally thought to evolve under natural selection. Those morphological and chemical traits can form highly correlated sets of traits. It is not always clear which of these are used by pollinators as primary targets of selection and which would be indirectly selected by being linked to those primary targets. Quantitative genetics tools for predicting multiple traits response to selection have been developed since long and have advanced our understanding of evolution of genetically correlated traits in various biological systems. We use these tools to predict the evolutionary trajectories of floral traits and understand the selection pressures acting on them. RESULTS We used data from an artificial selection and a pollinator (bumblebee, hoverfly) evolution experiment with fast cycling Brassica rapa plants to predict evolutionary changes of 12 floral volatiles and 4 morphological floral traits in response to selection. Using the observed selection gradients and the genetic variance-covariance matrix (G-matrix) of the traits, we showed that the observed responses of most floral traits including volatiles were predicted in the right direction in both artificial- and bumblebee-selection experiment. Genetic covariance had a mix of constraining and facilitating effects on evolutionary responses. We further revealed that G-matrices also evolved in the selection processes. CONCLUSIONS Overall, our integrative study shows that floral signals, especially volatiles, evolve under selection in a mostly predictable way, at least during short term evolution. Evolutionary constraints stemming from genetic covariance affected traits evolutionary trajectories and thus it is important to include genetic covariance for predicting the evolutionary changes of a comprehensive suite of traits. Other processes such as resource limitation and selfing also need to be considered for a better understanding of floral trait evolution.
Collapse
Affiliation(s)
- Pengjuan Zu
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, CH-8008, Zürich, Switzerland
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Florian P Schiestl
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, CH-8008, Zürich, Switzerland
| | - Daniel Gervasi
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, CH-8008, Zürich, Switzerland
| | - Xin Li
- Department of Plant Sciences, University of California Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Daniel Runcie
- Department of Plant Sciences, University of California Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Frédéric Guillaume
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland.
| |
Collapse
|
27
|
Zhou J, Reynolds RJ, Zimmer EA, Dudash MR, Fenster CB. Variable and sexually conflicting selection on
Silene stellata
floral traits by a putative moth pollinator selective agent. Evolution 2020; 74:1321-1334. [DOI: 10.1111/evo.13965] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 02/21/2020] [Accepted: 03/13/2020] [Indexed: 10/24/2022]
Affiliation(s)
- Juannan Zhou
- Simons Center for Quantitative Biology Cold Spring Harbor Laboratory Cold Spring Harbor NY 11724 USA
| | - Richard J. Reynolds
- Division of Clinical Immunology and Rheumatology, Department of Medicine University of Alabama at Birmingham Birmingham AL 35294 USA
| | - Elizabeth A. Zimmer
- Department of Botany National Museum of Natural History, MRC 166 Smithsonian Institution Washington DC 20013–7012 USA
| | - Michele R. Dudash
- Department of Natural Resource Management South Dakota State University Brookings SD 57007 USA
| | - Charles B. Fenster
- Department of Biology and Microbiology South Dakota State University Brookings SD 57007 USA
| |
Collapse
|
28
|
Velamazán M, Perea R, Bugalho MN. Ungulates and ecosystem services in Mediterranean woody systems: A semi-quantitative review. J Nat Conserv 2020. [DOI: 10.1016/j.jnc.2020.125837] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
29
|
Eisen KE, Wruck AC, Geber MA. Floral density and co‐occurring congeners alter patterns of selection in annual plant communities*. Evolution 2020; 74:1682-1698. [DOI: 10.1111/evo.13960] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 02/13/2020] [Accepted: 03/01/2020] [Indexed: 11/29/2022]
Affiliation(s)
- Katherine E. Eisen
- Department of Ecology and Evolutionary Biology Cornell University Ithaca New York 14853
| | - Amy C. Wruck
- Department of Ecology and Evolutionary Biology Cornell University Ithaca New York 14853
| | - Monica A. Geber
- Department of Ecology and Evolutionary Biology Cornell University Ithaca New York 14853
| |
Collapse
|
30
|
Panique H, Caruso CM. Simulated pollinator declines intensify selection on floral traits that facilitate selfing and outcrossing in Impatiens capensis. AMERICAN JOURNAL OF BOTANY 2020; 107:148-154. [PMID: 31828763 DOI: 10.1002/ajb2.1403] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 11/07/2019] [Indexed: 06/10/2023]
Abstract
PREMISE Anthropogenic environmental change is causing pollinator populations to decline. These declines should intensify selection for floral traits that facilitate outcrossing by making plants more attractive to pollinators and/or for floral traits that facilitate selfing in the absence of pollinators. However, the effect of pollinator declines on selection on floral traits could be modified by other environmental factors such as herbivores. METHODS We studied the effect of simulated pollinator declines on selection on floral traits of Impatiens capensis, a mixed-mating species that produces both obligately selfing cleistogamous flowers and primarily outcrossing chasmogamous flowers. We measured directional selection differentials via seeds per plant on two traits that facilitate outcrossing (chasmogamous flower size and number) and one trait that facilitates selfing (cleistogamous flower number) in ambient, reduced pollinator access, and reduced pollinator access combined with increased foliar herbivory treatments. RESULTS Reduced pollinator access intensified selection for larger chasmogamous flowers and more cleistogamous flowers. In contrast, increased herbivory did not affect selection on any floral trait. CONCLUSIONS Reduced pollinator access intensified selection for a trait that facilitates outcrossing, suggesting that even species such as I. capensis that can autonomously self-pollinate have the potential to respond to pollinator declines by evolving floral traits that reinforce interactions between plants and pollinators. However, reduced pollinator access also intensified selection for a trait that facilitates selfing, suggesting that I. capensis could adapt to pollinator declines by evolving floral traits that maintain the production of both selfed and outcrossed seeds.
Collapse
Affiliation(s)
- Hazel Panique
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Christina M Caruso
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| |
Collapse
|
31
|
Scopece G, Frachon L, Cozzolino S. Do native and invasive herbivores have an effect on Brassica rapa pollination? PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:927-934. [PMID: 30884071 DOI: 10.1111/plb.12985] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 03/11/2019] [Indexed: 06/09/2023]
Abstract
Mutualistic (e.g. pollination) and antagonistic (e.g. herbivory) plant-insect interactions shape levels of plant fitness and can have interactive effects. By using experimental plots of Brassica rapa plants infested with generalist (Mamestra brassicae) and specialised (Pieris brassicae) native herbivores and with a generalist invasive (Spodoptera littoralis) herbivore, we estimated both pollen movement among treatments and the visiting behaviour of honeybees versus other wild pollinators. Overall, we found that herbivory has weak effects on plant pollen export, either in terms of inter-treatment movements or of dispersion distance. Plants infested with the native specialised herbivore tend to export less pollen to other plants with the same treatment. Other wild pollinators preferentially visit non-infested plants that differ from those of honeybees, which showed no preferences. Honeybees and other wild pollinators also showed different behaviours on plants infested with different herbivores, with the former tending to avoid revisiting the same treatment and the latter showing no avoidance behaviour. When taking into account the whole pollinator community, i.e. the interactive effects of honeybees and other wild pollinators, we found an increased avoidance of plants infested by the native specialised herbivore and a decreased avoidance of plants infested by the invasive herbivore. Taken together, our results suggest that herbivory may have an effect on B. rapa pollination, but this effect depends on the relative abundance of honeybees and other wild pollinators.
Collapse
Affiliation(s)
- G Scopece
- Department of Biology, University of Naples Federico II, Complesso Universitario MSA, Naples, Italy
| | - L Frachon
- Department of Biology, University of Naples Federico II, Complesso Universitario MSA, Naples, Italy
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland
| | - S Cozzolino
- Department of Biology, University of Naples Federico II, Complesso Universitario MSA, Naples, Italy
| |
Collapse
|
32
|
Kemp JE, Ellis AG. Cryptic petal coloration decreases floral apparency and herbivory in nocturnally closing daisies. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13423] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Jurene E. Kemp
- Botany and Zoology Department Stellenbosch University Stellenbosch South Africa
| | - Allan G. Ellis
- Botany and Zoology Department Stellenbosch University Stellenbosch South Africa
| |
Collapse
|
33
|
Trunschke J, Sletvold N, Ågren J. The independent and combined effects of floral traits distinguishing two pollination ecotypes of a moth-pollinated orchid. Ecol Evol 2019; 9:1191-1201. [PMID: 30805152 PMCID: PMC6374684 DOI: 10.1002/ece3.4808] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 10/22/2018] [Accepted: 11/01/2018] [Indexed: 11/26/2022] Open
Abstract
Identifying traits and agents of selection involved in local adaptation is important for understanding population divergence. In southern Sweden, the moth-pollinated orchid Platanthera bifolia occurs as a woodland and a grassland ecotype that differ in dominating pollinators. The woodland ecotype is taller (expected to influence pollinator attraction) and produces flowers with longer spurs (expected to influence efficiency of pollen transfer) compared to the grassland ecotype. We examined whether plant height and spur length affect pollination and reproductive success in a woodland population, and whether effects are non-additive, as expected for traits influencing two multiplicative components of pollen transfer. We reduced plant height and spur length to match trait values observed in the grassland ecotype and determined the effects on pollen removal, pollen receipt, and fruit production. In addition, to examine the effects of naturally occurring variation, we quantified pollinator-mediated selection through pollen removal and seed production in the same population. Reductions of plant height and spur length decreased pollen removal, number of flowers receiving pollen, mean pollen receipt per pollinated flower, and fruit production per plant, but no significant interaction effect was detected. The selection analysis demonstrated pollinator-mediated selection for taller plants via female fitness. However, there was no current selection mediated by pollinators on spur length, and pollen removal was not related to plant height or spur length. The results show that, although both traits are important for pollination success and female fitness in the woodland habitat, only plant height was sufficiently variable in the study population for current pollinator-mediated selection to be detected. More generally, the results illustrate how a combination of experimental approaches can be used to identify both traits and agents of selection.
Collapse
Affiliation(s)
- Judith Trunschke
- Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology CentreUppsala UniversityUppsalaSweden
| | - Nina Sletvold
- Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology CentreUppsala UniversityUppsalaSweden
| | - Jon Ågren
- Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology CentreUppsala UniversityUppsalaSweden
| |
Collapse
|
34
|
Transgenerational effects of ungulates and pre-dispersal seed predators on offspring success and resistance to herbivory. PLoS One 2018; 13:e0207553. [PMID: 30540778 PMCID: PMC6291102 DOI: 10.1371/journal.pone.0207553] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 11/01/2018] [Indexed: 11/19/2022] Open
Abstract
Herbivorous mammals and insect pre-dispersal seed predators are two types of herbivores that, despite their functional and morphological differences, tend to severely impact many plant species, highly decreasing their seed production and even imperiling the performance of their offspring through transgenerational effects. However, how they influence offspring resistance to herbivory remains largely unknown. In this study we experimentally examined the effects of ungulates and pre-dispersal seed predators on seed quality as well as on the emergence, survival and resistance to herbivory of the seedlings of a semiarid herb. We found that ungulates reduced seedling recruitment but increased seedling resistance to leaf miners. These effects were probably a consequence of insufficient carbon provisioning in seeds that reduced seed viability and provoked carbon limitation in seedlings. Pre-dispersal seed predators did not influence seedling recruitment, but seedlings from mothers damaged by ungulates and by pre-dispersal seed predators suffered less herbivory by grasshoppers. Remarkably, intra-individual differences in damage by pre-dispersal seed predators affected the rate of damage underwent by seedlings. That is, seedlings derived from fruits attacked by seed predators were more resistant to herbivores than siblings derived from un-attacked fruits in plant populations exposed to ungulates. To our knowledge, this is the first study reporting variation in transgenerational-induced resistance of seedlings from the same maternal plant. This study is a valuable contribution to the understanding of transgenerational effects of multiple herbivores and their implications for a deeper comprehension of the natural systems in which they co-occur.
Collapse
|
35
|
Caruso CM, Eisen KE, Martin RA, Sletvold N. A meta-analysis of the agents of selection on floral traits. Evolution 2018; 73:4-14. [PMID: 30411337 DOI: 10.1111/evo.13639] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 10/23/2018] [Accepted: 10/24/2018] [Indexed: 01/03/2023]
Abstract
Floral traits are hypothesized to evolve primarily in response to selection by pollinators. However, selection can also be mediated by other environmental factors. To understand the relative importance of pollinator-mediated selection and its variation among trait and pollinator types, we analyzed directional selection gradients on floral traits from experiments that manipulated the environment to identify agents of selection. Pollinator-mediated selection was stronger than selection by other biotic factors (e.g., herbivores), but similar in strength to selection by abiotic factors (e.g., soil water), providing partial support for the hypothesis that floral traits evolve primarily in response to pollinators. Pollinator-mediated selection was stronger on pollination efficiency traits than on other trait types, as expected if efficiency traits affect fitness via interactions with pollinators, but other trait types also affect fitness via other environmental factors. In addition to varying among trait types, pollinator-mediated selection varied among pollinator taxa: selection was stronger when bees, long-tongued flies, or birds were the primary visitors than when the primary visitors were Lepidoptera or multiple animal taxa. Finally, reducing pollinator access to flowers had a relatively small effect on selection on floral traits, suggesting that anthropogenic declines in pollinator populations would initially have modest effects on floral evolution.
Collapse
Affiliation(s)
- Christina M Caruso
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Katherine E Eisen
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada.,Current Address: Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, 14853
| | - Ryan A Martin
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, 44106
| | - Nina Sletvold
- Department of Ecology and Genetics, Uppsala University, Uppsala, 751 05, Sweden
| |
Collapse
|
36
|
Thomann M, Ehrlén J, Ågren J. Grazers affect selection on inflorescence height both directly and indirectly and effects change over time. Ecology 2018; 99:2167-2175. [PMID: 30047592 DOI: 10.1002/ecy.2470] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Revised: 06/20/2018] [Accepted: 07/05/2018] [Indexed: 11/06/2022]
Abstract
Selection mediated by one biotic agent will often be modified by the presence of other biotic interactions, and the importance of such indirect effects might change over time. We conducted an 11-yr field experiment to test the prediction that large grazers affect selection on floral display of the dimorphic herb Primula farinosa not only directly through differential grazing damage, but also indirectly by affecting vegetation height and thereby selection mediated by pollinators and seed predators. Exclusion of large grazers increased vegetation height and the strength of pollinator-mediated selection for tall inflorescences and seed-predator-mediated selection for short inflorescences. The direct effect of grazers on selection resulting from differential grazing damage to the two scape morphs showed no temporal trend. By contrast, the increase in vegetation height in exclosures over time was associated with an increase in selection mediated by pollinators and seed predators. In the early years of the experiment, the indirect effects of grazers on selection mediated by pollinators and seed predators were weak, whereas at the end of the experiment, the indirect effects were of similar magnitude as the direct effect due to differential grazing damage. The results demonstrate that the indirect effects of a selective agent can be as strong as its direct effects, and that the relative importance of direct vs. indirect effects on selection can change over time. A full understanding of the ecological processes governing variation in selection thus requires that both direct and indirect effects of biotic interactions are assessed.
Collapse
Affiliation(s)
- Michel Thomann
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, SE-752 36, Uppsala, Sweden
| | - Johan Ehrlén
- Department of Ecology, Environment, and Plant Sciences, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Jon Ågren
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, SE-752 36, Uppsala, Sweden
| |
Collapse
|
37
|
Wood CW, Pilkington BL, Vaidya P, Biel C, Stinchcombe JR. Genetic conflict with a parasitic nematode disrupts the legume-rhizobia mutualism. Evol Lett 2018; 2:233-245. [PMID: 30283679 PMCID: PMC6121810 DOI: 10.1002/evl3.51] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 02/07/2018] [Accepted: 03/09/2018] [Indexed: 12/13/2022] Open
Abstract
Genetic variation for partner quality in mutualisms is an evolutionary paradox. One possible resolution to this puzzle is that there is a tradeoff between partner quality and other fitness‐related traits. Here, we tested whether susceptibility to parasitism is one such tradeoff in the mutualism between legumes and nitrogen‐fixing bacteria (rhizobia). We performed two greenhouse experiments with the legume Medicago truncatula. In the first, we inoculated each plant with the rhizobia Ensifer meliloti and with one of 40 genotypes of the parasitic root‐knot nematode Meloidogyne hapla. In the second experiment, we inoculated all plants with rhizobia and half of the plants with a genetically variable population of nematodes. Using the number of nematode galls as a proxy for infection severity, we found that plant genotypes differed in susceptibility to nematode infection, and nematode genotypes differed in infectivity. Second, we showed that there was a genetic correlation between the number of mutualistic structures formed by rhizobia (nodules) and the number of parasitic structures formed by nematodes (galls). Finally, we found that nematodes disrupt the rhizobia mutualism: nematode‐infected plants formed fewer nodules and had less nodule biomass than uninfected plants. Our results demonstrate that there is genetic conflict between attracting rhizobia and repelling nematodes in Medicago. If genetic conflict with parasitism is a general feature of mutualism, it could account for the maintenance of genetic variation in partner quality and influence the evolutionary dynamics of positive species interactions.
Collapse
Affiliation(s)
- Corlett W Wood
- Department of Ecology and Evolutionary Biology University of Toronto Toronto Ontario M5S3B2 Canada
| | - Bonnie L Pilkington
- Department of Ecology and Evolutionary Biology University of Toronto Toronto Ontario M5S3B2 Canada
| | - Priya Vaidya
- Department of Ecology and Evolutionary Biology University of Toronto Toronto Ontario M5S3B2 Canada
| | - Caroline Biel
- Department of Ecology and Evolutionary Biology University of Toronto Toronto Ontario M5S3B2 Canada
| | - John R Stinchcombe
- Department of Ecology and Evolutionary Biology University of Toronto Toronto Ontario M5S3B2 Canada.,Koffler Scientific Reserve University of Toronto Toronto Ontario M5S3B2 Canada
| |
Collapse
|
38
|
Crab spiders impact floral-signal evolution indirectly through removal of florivores. Nat Commun 2018; 9:1367. [PMID: 29636464 PMCID: PMC5893632 DOI: 10.1038/s41467-018-03792-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 03/13/2018] [Indexed: 02/05/2023] Open
Abstract
The puzzling diversity of flowers is primarily shaped by selection and evolutionary change caused by the plant's interaction with animals. The contribution of individual animal species to net selection, however, may vary depending on the network of interacting organisms. Here we document that in the buckler mustard, Biscutella laevigata, the crab spider Thomisus onustus reduces bee visits to flowers but also benefits plants by feeding on florivores. Uninfested plants experience a trade-off between pollinator and spider attraction as both bees and crab spiders are attracted by the floral volatile β-ocimene. This trade-off is reduced by the induced emission of β-ocimene after florivore infestation, which is stronger in plant populations where crab spiders are present than where they are absent, suggesting that plants are locally adapted to the presence of crab spiders. Our study demonstrates the context-dependence of selection and shows how crab spiders impact on floral evolution.
Collapse
|
39
|
terHorst CP, Zee PC, Heath KD, Miller TE, Pastore AI, Patel S, Schreiber SJ, Wade MJ, Walsh MR. Evolution in a Community Context: Trait Responses to Multiple Species Interactions. Am Nat 2018. [DOI: 10.1086/695835] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
40
|
Joly S, Lambert F, Alexandre H, Clavel J, Léveillé‐Bourret É, Clark JL. Greater pollination generalization is not associated with reduced constraints on corolla shape in Antillean plants. Evolution 2018; 72:244-260. [DOI: 10.1111/evo.13410] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 11/29/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Simon Joly
- Montreal Botanical Garden 4101 Sherbrooke East Montréal QC, H1X 2B2 Canada
- Institut de recherche en biologie végétale, Département de sciences biologiquesUniversité de MontréalMontréal Canada
| | - François Lambert
- Institut de recherche en biologie végétale, Département de sciences biologiquesUniversité de MontréalMontréal Canada
| | - Hermine Alexandre
- Institut de recherche en biologie végétale, Département de sciences biologiquesUniversité de MontréalMontréal Canada
| | - Julien Clavel
- École Normale Supérieure, Paris Sciences et Lettres (PSL) Research University, Institut de Biologie de l'École Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm F‐75005 Paris France
| | - Étienne Léveillé‐Bourret
- Institut de recherche en biologie végétale, Département de sciences biologiquesUniversité de MontréalMontréal Canada
- Current Address: Department of BiologyUniversity of OttawaOttawa Canada
| | - John L. Clark
- Department of Biological SciencesThe University of AlabamaTuscaloosa, Alabama 35487
- Science DepartmentThe Lawrenceville SchoolLawrenceville, New Jersey U.S.A
| |
Collapse
|
41
|
Mori E, Mazza G, Saggiomo L, Sommese A, Esattore B. Strangers Coming from the Sahara: An Update of the Worldwide Distribution, Potential Impacts and Conservation Opportunities of Alien Aoudad. ANN ZOOL FENN 2017. [DOI: 10.5735/086.054.0501] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Emiliano Mori
- Research Unit of Behavioural Ecology, Ethology and Wildlife Management, Department of Life Sciences, University of Siena, Via P.A. Mattioli 4, IT-53100 Siena, Italy
| | - Giuseppe Mazza
- Council for Agricultural Research and Economics, Agrobiology and Pedology Research Centre (CREA-ABP), Via Lanciola 12/A, Cascine del Riccio, IT-50125 Firenze, Italy
| | - Laura Saggiomo
- Czech University of Life Sciences (Č.Z.U.), Faculty of Forestry and Wood Sciences, Department of Game Management and Wildlife Biology, Kamýcká 961/129, CZ-165 21 Prague, Czech Republic
| | - Andrea Sommese
- Czech University of Life Sciences (Č.Z.U.), Faculty of Agrobiology, Food and Natural Resources, Department of Animal Husbandry and Ethology, Kamýcká 961/129, CZ-165 00 Prague, Czech Republic
- Institute of Animal Science (V.Ú.Ž.V.), Department of Ethology, Přáteiství 815, CZ-10400 Prague, Czech Republic
| | - Bruno Esattore
- Czech University of Life Sciences (Č.Z.U.), Faculty of Agrobiology, Food and Natural Resources, Department of Animal Husbandry and Ethology, Kamýcká 961/129, CZ-165 00 Prague, Czech Republic
- Institute of Animal Science (V.Ú.Ž.V.), Department of Ethology, Přáteiství 815, CZ-10400 Prague, Czech Republic
| |
Collapse
|
42
|
Chen L, Zhang B, Li Q. Pollinator-mediated selection on flowering phenology and floral display in a distylous herb Primula alpicola. Sci Rep 2017; 7:13157. [PMID: 29030594 PMCID: PMC5640686 DOI: 10.1038/s41598-017-13340-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 09/12/2017] [Indexed: 12/17/2022] Open
Abstract
The targets and causes of phenotypic selection are crucial to understanding evolutionary ecology. However, few studies have examined selection quantitatively from multiple sources on the same trait identified the agent of natural selection experimentally. Here we quantified phenotypic selection on traits, including flowering phenology and aspects of floral display via female fitness, in the distylous perennial herb Primula alpicola. To determine the role of pollinators in generating selection effects on floral traits, we compared the phenotypic selection gradients in open-pollinated and hand-pollinated plants. Our results show that pollinator-mediated linear selection on flowering start and correlational selection on the number of flowers and scape height explains most of the net phenotypic selection on these traits suggesting pollinators played an important role in shaping floral diversity. We used path analysis and structural equation modeling (SEM) to examine how herbivores affected the relationship between floral traits and female fitness, but no significant selection was caused by seed predators. These results suggest pollinators, not herbivores maybe the significant agent of selection on flora traits.
Collapse
Affiliation(s)
- Lingling Chen
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Science, Mengla, 666303, China.,University of Chinese Academy of Sciences, Beijing, 10049, China
| | - Bo Zhang
- College of Pratacultural Science, Gansu Agricultural University, Lanzhou, 730070, China
| | - Qingjun Li
- Laboratory of Ecology and Evolution Biology, State Key Laboratory in Conservation and Utilization of Bioresources in Yunnan, Yunnan University, Kunming, Yunnan, 650091, China.
| |
Collapse
|
43
|
Scopece G, Juillet N, Lexer C, Cozzolino S. Fluctuating selection across years and phenotypic variation in food-deceptive orchids. PeerJ 2017; 5:e3704. [PMID: 28852594 PMCID: PMC5572944 DOI: 10.7717/peerj.3704] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 07/27/2017] [Indexed: 11/20/2022] Open
Abstract
Nectarless flowers that deceive pollinators offer an opportunity to study asymmetric plant-insect interactions. Orchids are a widely used model for studying these interactions because they encompass several thousand species adopting deceptive pollination systems. High levels of intra-specific phenotypic variation have been reported in deceptive orchids, suggesting a reduced consistency of pollinator-mediated selection on their floral traits. Nevertheless, several studies report on widespread directional selection mediated by pollinators even in these deceptive orchids. In this study we test the hypothesis that the observed selection can fluctuate across years in strength and direction thus likely contributing to the phenotypic variability of this orchid group. We performed a three-year study estimating selection differentials and selection gradients for nine phenotypic traits involved in insect attraction in two Mediterranean orchid species, namely Orchis mascula and O. pauciflora, both relying on a well-described food-deceptive pollination strategy. We found weak directional selection and marginally significant selection gradients in the two investigated species with significant intra-specific differences in selection differentials across years. Our data do not link this variation with a specific environmental cause, but our results suggest that pollinator-mediated selection in food-deceptive orchids can change in strength and in direction over time. In perennial plants, such as orchids, different selection differentials in the same populations in different flowering seasons can contribute to the maintenance of phenotypic variation often reported in deceptive orchids.
Collapse
Affiliation(s)
- Giovanni Scopece
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Nicolas Juillet
- UMR Peuplements Végétaux et Bioagresseurs en Milieu Tropical, Université de la Réunion, Pôle de Protection des Plantes, Saint Pierre, La Réunion, France
| | - Christian Lexer
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
| | | |
Collapse
|
44
|
Zhang G, Meng L, Wu Z, Zhang Z, Yin L, Yang Y, Duan Y. Natural selection on floral traits of Caltha scaposa (Ranunculaceae), an alpine perennial with generalized pollination system from Northwest Yunnan. PLANT DIVERSITY 2017; 39:202-207. [PMID: 30159512 PMCID: PMC6112295 DOI: 10.1016/j.pld.2017.03.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 03/16/2017] [Indexed: 05/23/2023]
Abstract
Floral traits, including those invisible to humans but visible to pollinators, that increase pollination efficiency may be selected by pollinators in plant species with pollen limitation of seed production, but the importance of pollinators as selective agents on different floral traits needs to be further quantified experimentally. In the present study, we examined selective strength on flower diameter, flower height, UV bulls-eye size, sepal size and UV proportion via female fitness in Caltha scaposa, based on open-pollinated and hand-pollinated flowers, through which pollinator-mediated selection was calculated for each of floral traits. Our results suggest that seed production of C. scaposa is pollen limited in natural conditions. There was directional selection (Δβpollinator = -0.12) for larger flowers in open-pollinated flowers, while no significant selection was found in flower height, UV bulls-eye size, sepal size or UV proportion. Statistically significant selection was found in UV bulls-eye size, sepal size and UV proportion in hand-pollinated flowers, but interactions with pollinators contributed only to flower diameter. We conclude that in C. scaposa, floral traits that are subjected to selection might be driven by multiple selective agents, and suggest the importance of investigating floral traits that are invisible to human but visible to pollinators in measuring pollinator-mediated selection via male fitness.
Collapse
Affiliation(s)
- Guopeng Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China
- School of Life Sciences, Yunnan Normal University, Kunming 650092, PR China
| | - Lihua Meng
- School of Life Sciences, Yunnan Normal University, Kunming 650092, PR China
| | - Zhikun Wu
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China
| | - Zhiqiang Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China
| | - Lingjuan Yin
- National Technical Secondary School of Lijiang, Lijiang 674119, PR China
| | - Yongping Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China
| | - Yuanwen Duan
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China
| |
Collapse
|
45
|
Gargano D, Fenu G, Bernardo L. Local shifts in floral biotic interactions in habitat edges and their effect on quantity and quality of plant offspring. AOB PLANTS 2017; 9:plx031. [PMID: 28775831 PMCID: PMC5534021 DOI: 10.1093/aobpla/plx031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 06/24/2017] [Accepted: 07/07/2017] [Indexed: 06/07/2023]
Abstract
Spatial shifts in insect fauna due to ecological heterogeneity can severely constrain plant reproduction. Nonetheless, data showing effects of insect visit patterns and intensity of mutualistic and/or antagonistic plant-insect interactions on plant reproduction over structured ecological gradients remain scarce. We investigated how changes in flower-visitor abundance, identity and behaviour over a forest-open habitat gradient affect plant biotic interactions, and quantitative and qualitative fitness in the edge-specialist Dianthus balbisii. Composition and behaviour of the insects visiting flowers of D. balbisii strongly varied over the study gradient, influencing strength and patterns of plant biotic interactions (i.e. herbivory and pollination likelihood). Seed set comparison in free- and manually pollinated flowers suggested spatial variations in the extent of quantitative pollen limitation, which appeared more pronounced at the gradient extremes. Such variations were congruent to patterns of flower visit and plant biotic interactions. The analyses on seed and seedling viability evidenced that spatial variation in amount and type of pollinators, and frequency of herbivory affected qualitative fitness of D. balbisii by influencing selfing and outcrossing rates. Our work emphasizes the role of plant biotic interactions as a fine-scale mediator of plant fitness in ecotones, highlighting that optimal plant reproduction can take place into a restricted interval of the ecological gradients occurring at forest edges. Reducing the habitat complexity typical of such transition contexts can threat edge-adapted plants.
Collapse
Affiliation(s)
- Domenico Gargano
- Dipartimento di Biologia, Ecologia e Scienze della Terra dell’Università della Calabria, Via P. Bucci, I-87036 Arcavacata di Rende, Italy
| | - Giuseppe Fenu
- Centro Conservazione Biodiversità (CCB), Dipartimento di Scienze della Vita e dell’Ambiente, Università degli Studi di Cagliari, Viale Sant’Ignazio da Laconi, 11–13, I-09123 Cagliari, Italy
| | - Liliana Bernardo
- Dipartimento di Biologia, Ecologia e Scienze della Terra dell’Università della Calabria, Via P. Bucci, I-87036 Arcavacata di Rende, Italy
| |
Collapse
|
46
|
Thomsen CJM, Sargent RD. Evidence that a herbivore tolerance response affects selection on floral traits and inflorescence architecture in purple loosestrife (Lythrum salicaria). ANNALS OF BOTANY 2017; 119:1295-1303. [PMID: 28369263 PMCID: PMC5604591 DOI: 10.1093/aob/mcx026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 02/22/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND AND AIMS The study of the evolution of floral traits has generally focused on pollination as the primary driver of selection. However, herbivores can also impose selection on floral traits through a variety of mechanisms, including florivory and parasitism. Less well understood is whether floral and inflorescence architecture traits that influence a plant's tolerance to herbivory, such as compensatory regrowth, alter pollinator-mediated selection. METHODS Because herbivore damage to Lythrum salicaria meristems typically leads to an increase in the number of inflorescences and the size of the floral display, an experiment was conducted to test whether simulated herbivory (i.e. clipping the developing meristem) could alter the magnitude or direction of pollinator-mediated selection on a suite of floral and inflorescence architecture traits. Using a pollen supplementation protocol, pollen limitation was compared in the presence and absence of meristem damage in order to quantify any interaction between pollinator and herbivore-mediated selection on floral traits. KEY RESULTS Surprisingly, in spite of an obvious impact on floral display and architecture, with clipped plants producing more inflorescences and more flowers, there was no difference in pollen limitation between clipped and unclipped plants. Correspondingly, there was no evidence that imposing herbivore damage altered pollinator-mediated selection in this system. Rather, the herbivory treatment alone was found to alter direct selection on floral display, with clipped plants experiencing greater selection for earlier flowering and weaker selection for number of inflorescences when compared with unclipped plants. CONCLUSIONS These findings imply that herbivory on its own can drive selection on plant floral traits and inflorescence architecture in this species, even more so than pollinators. Specifically, herbivory can impose selection on floral traits if such traits influence a plant's tolerance to herbivory, such as through the timing of flowering and/or the compensatory regrowth response.
Collapse
Affiliation(s)
- Christina J. M. Thomsen
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
| | - Risa D. Sargent
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
| |
Collapse
|
47
|
Lecomte X, Caldeira MC, Bugalho MN, Fedriani JM. Combined effects of deer, mice and insect seed predation on the reproductive success of a Mediterranean shrub. Basic Appl Ecol 2017. [DOI: 10.1016/j.baae.2017.03.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
48
|
Zu P, Schiestl FP. The effects of becoming taller: direct and pleiotropic effects of artificial selection on plant height in Brassica rapa. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 89:1009-1019. [PMID: 27889935 DOI: 10.1111/tpj.13440] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/07/2016] [Accepted: 11/18/2016] [Indexed: 06/06/2023]
Abstract
Plant height is an important trait for plant reproductive success. Plant height is often under pollinator-mediated selection, and has been shown to be correlated with various other traits. However, few studies have examined the evolutionary trajectory of plant height under selection and the pleiotropic effects of plant height evolution. We conducted a bi-directional artificial selection experiment on plant height with fast cycling Brassica rapa plants to estimate its heritability and genetic correlations, and to reveal evolutionary responses to artificial selection on height and various correlated traits. With the divergent lines obtained through artificial selection, we subsequently conducted pollinator-choice assays and investigated resource limitation of fruit production. We found that plant height variation is strongly genetically controlled (with a realized heritability of 41-59%). Thus, plant height can evolve rapidly under phenotypic selection. In addition, we found remarkable pleiotropic effects in phenology, morphology, floral scent, color, nectar and leaf glucosinolates. Most traits were increased in tall-line plants, but flower size, UV reflection and glucosinolates were decreased, indicating potential trade-offs. Pollinators preferred plants of the tall selection lines over the short selection lines in both greenhouse experiments with bumblebees and field experiment with natural pollinators. We did not detect any differences in resource limitation between plants of the different selection lines. Overall, our study predicts that increased height should evolve under positive pollinator-mediated directional selection with potential trade-offs in floral signals and herbivore defense.
Collapse
Affiliation(s)
- Pengjuan Zu
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | - Florian P Schiestl
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| |
Collapse
|
49
|
Muñoz-Pajares AJ, García C, Abdelaziz M, Bosch J, Perfectti F, Gómez JM. Drivers of genetic differentiation in a generalist insect-pollinated herb across spatial scales. Mol Ecol 2017; 26:1576-1585. [DOI: 10.1111/mec.13971] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 11/05/2016] [Accepted: 12/05/2016] [Indexed: 11/28/2022]
Affiliation(s)
- A. J. Muñoz-Pajares
- Plant Biology; CIBIO/InBio; Centro de Investigação em Biodiversidade e Recursos Genéticos; Laboratório Associado; Universidade do Porto; Campus Agrário de Vairão 4485-661 Vairão Portugal
- Departamento de Genética; Universidad de Granada; Granada Spain
| | - C. García
- Plant Biology; CIBIO/InBio; Centro de Investigação em Biodiversidade e Recursos Genéticos; Laboratório Associado; Universidade do Porto; Campus Agrário de Vairão 4485-661 Vairão Portugal
| | - M. Abdelaziz
- Departamento de Genética; Universidad de Granada; Granada Spain
- Biological and Environmental Sciences; School of Natural Sciences; University of Stirling; Stirling FK9 4LA UK
| | - J. Bosch
- CREAF (Centre de Recerca Ecològica i Aplicacions Forestals); Universitat Autònoma de Barcelona; 08193 Bellaterra Barcelona Spain
| | - F. Perfectti
- Departamento de Genética; Universidad de Granada; Granada Spain
| | - J. M. Gómez
- Departamento de Ecología; Universidad de Granada; Granada Spain
- Departamento de Ecología Funcional y Evolutiva; Estación Experimental de Zonas Aridas (EEZACSIC); Almería Spain
| |
Collapse
|
50
|
Sapir Y. Pollinator‐mediated selection is better detected when controlling for resource limitation. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12800] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yuval Sapir
- The Botanical Garden School of Plant Sciences and Food Security Tel Aviv University Ramat Aviv Tel Aviv69978 Israel
| |
Collapse
|