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Powers JM, Briggs HM, Campbell DR. Natural selection on floral volatiles and other traits can change with snowmelt timing and summer precipitation. THE NEW PHYTOLOGIST 2024. [PMID: 39329349 DOI: 10.1111/nph.20157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Accepted: 09/09/2024] [Indexed: 09/28/2024]
Abstract
Climate change is disrupting floral traits that mediate mutualistic and antagonistic species interactions. Plastic responses of these traits to multiple shifting conditions may be adaptive, depending on natural selection in new environments. We manipulated snowmelt date over three seasons (3-11 d earlier) in factorial combination with growing-season precipitation (normal, halved, or doubled) to measure plastic responses of volatile emissions and other floral traits in Ipomopsis aggregata. We quantified how precipitation and early snowmelt affected selection on traits by seed predators and pollinators. Within years, floral emissions did not respond to precipitation treatments but shifted with snowmelt treatment depending on the year. Across 3 yr, emissions correlated with both precipitation and snowmelt date. These effects were driven by changes in soil moisture. Selection on several traits changed with earlier snowmelt or reduced precipitation, in some cases driven by predispersal seed predation. Floral trait plasticity was not generally adaptive. Floral volatile emissions shifted in the face of two effects of climate change, and the new environments modulated selection imposed by interacting species. The complexity of the responses underscores the need for more studies of how climate change will affect floral volatiles and other floral traits.
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Affiliation(s)
- John M Powers
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, 92697, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO, 81224, USA
| | - Heather M Briggs
- Rocky Mountain Biological Laboratory, Crested Butte, CO, 81224, USA
- College of Science, University of Utah, Salt Lake City, UT, 84102, USA
| | - Diane R Campbell
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, 92697, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO, 81224, USA
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Campbell DR, Bischoff M, Raguso RA, Briggs HM, Sosenski P. Selection of Floral Traits by Pollinators and Seed Predators during Sequential Life History Stages. Am Nat 2022; 199:808-823. [DOI: 10.1086/716740] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Diane R. Campbell
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92617
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado 81224
| | - Mascha Bischoff
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado 81224
- Environmental Research Institute, North Highland College, Castle Street, Thurso KW14 7JD, United Kingdom
| | - Robert A. Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York 14853
| | - Heather M. Briggs
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92617
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado 81224
| | - Paula Sosenski
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92617
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado 81224
- Consejo Nacional de Ciencia y Tecnología (CONACYT)–Departamento de Ecología Tropical, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
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Brody AK, Burnham PA, Smith B. Feeding friend and foe: ample pollen mitigates the effects of pollen theft for a gynodioecious plant, Polemonium foliosissimum (Polemoniaceae). ANNALS OF BOTANY 2021; 128:127-134. [PMID: 33849077 PMCID: PMC8318250 DOI: 10.1093/aob/mcab050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 04/08/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND AND AIMS Most angiosperms rely on pollinators to transport pollen and effect fertilization. While some floral visitors are effective pollinators, others act as thieves, consuming pollen but effecting little pollination in return. The importance of pollen theft in male and female reproductive success has received little attention. Here, we examined if pollen consumption by flies altered pollen receipt and exacerbated pollen limitation for a bumblebee-pollinated plant, Polemonium foliosissimum (Polemoniaceae). METHODS To examine the effect of pollen-thieving flies, we took a three-pronged approach. First, we used single-visit observations to quantify pollen removal and pollen deposition by flies and bumblebees. Second, we manipulated pollen in the neighbourhood around focal plants in two years to test whether pollen reduction reduced pollen receipt. Third, we combined pollen reduction with hand-pollination to test whether pollen thieving exacerbated pollen limitation. Polemonium foliosissimum is gynodioecious in most populations in the Elk Mountains of central Colorado, USA. Thus, we also tested whether pollen theft affected hermaphrodites and females differently. RESULTS Flies removed significantly more pollen and deposited less pollen per visit than did bumblebees. Reduction of pollen in the neighbourhood around focal plants reduced pollen receipt in both years but only nearly significantly so in 2015. In 2016, plants were significantly pollen-limited; hand-pollination significantly increased seeds per fruit for both hermaphrodites and females. However, the reduction of pollen around focal plants did not exacerbate pollen limitation for either hermaphrodites or females. CONCLUSIONS Our results suggest that plants tolerate significant consumption of pollen by thieves and pollinators by producing ample pollen to feed both and fertilize available ovules. Our results demonstrate that pollen limitation in P. foliosissimum is driven by lack of effective pollinators rather than lack of pollen. Teasing out these effects elucidates the relative importance of drivers of reproductive success and thus the expected response to selection by different floral visitors.
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Affiliation(s)
- Alison K Brody
- Department of Biology, University of Vermont, Burlington, VT, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO, USA
| | | | - Brittany Smith
- Rocky Mountain Biological Laboratory, Crested Butte, CO, USA
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Underwood N, Hambäck PA, Inouye BD. Pollinators, Herbivores, and Plant Neighborhood Effects. THE QUARTERLY REVIEW OF BIOLOGY 2020. [DOI: 10.1086/707863] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Early snowmelt projected to cause population decline in a subalpine plant. Proc Natl Acad Sci U S A 2019; 116:12901-12906. [PMID: 31182600 DOI: 10.1073/pnas.1820096116] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
How climate change influences the dynamics of plant populations is not well understood, as few plant studies have measured responses of vital rates to climatic variables and modeled the impact on population growth. The present study used 25 y of demographic data to analyze how survival, growth, and fecundity respond to date of spring snowmelt for a subalpine plant. Fecundity was estimated by seed production (over 15 y) and also divided into flower number, fruit set, seeds per fruit, and escape from seed predation. Despite no apparent effects on flower number, plants produced more seeds in years with later snowmelt. Survival and probability of flowering were reduced by early snowmelt in the previous year. Based on demographic models, earlier snowmelt with warming is expected to lead to negative population growth, driven especially by changes in seedling establishment and seed production. These results provide a rare example of how climate change is expected to influence the dynamics of a plant population. They furthermore illustrate the potential for strong population impacts even in the absence of more commonly reported visual signs, such as earlier blooming or reduced floral display in early melting years.
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Campbell DR, Sosenski P, Raguso RA. Phenotypic plasticity of floral volatiles in response to increasing drought stress. ANNALS OF BOTANY 2019; 123:601-610. [PMID: 30364929 PMCID: PMC6417471 DOI: 10.1093/aob/mcy193] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 10/04/2018] [Indexed: 05/20/2023]
Abstract
BACKGROUND AND AIMS Flowers emit a wide range of volatile compounds which can be critically important to interactions with pollinators or herbivores. Yet most studies of how the environment influences plant volatiles focus on leaf emissions, with little known about abiotic sources of variation in floral volatiles. Understanding phenotypic plasticity in floral volatile emissions has become increasingly important with globally increasing temperatures and changes in drought frequency and severity. Here quantitative relationships of floral volatile emissions to soil water content were analysed. METHODS Plants of the sub-alpine herb Ipomopsis aggregata and hybrids with its closest congener were subjected to a progressive dry down, mimicking the range of soil moistures experienced in the field. Floral volatiles and leaf gas exchange were measured at four time points during the drought. KEY RESULTS As the soil dried, floral volatile emissions increased overall and changed in composition, from more 1,3-octadiene and benzyl alcohol to higher representation of some terpenes. Emissions of individual compounds were not linearly related to volumetric water content in the soil. The dominant compound, the monoterpene α-pinene, made up the highest percentage of the scent mixture when soil moisture was intermediate. In contrast, emission of the sesquiterpene (E,E)-α-farnesene accelerated as the drought became more intense. Changes in floral volatiles did not track the time course of changes in photosynthetic rate or stomatal conductance. CONCLUSIONS This study shows responses of specific floral volatile organic compounds to soil moisture. The non-linear responses furthermore suggest that extreme droughts may have impacts that are not predictable from milder droughts. Floral volatiles are likely to change seasonally with early summer droughts in the Rocky Mountains, as well as over years as snowmelt becomes progressively earlier. Changes in water availability may have impacts on plant-animal interactions that are mediated through non-linear changes in floral volatiles.
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Affiliation(s)
- Diane R Campbell
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO, USA
- For correspondence. E-mail
| | - Paula Sosenski
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO, USA
- CONACYT – Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, México
| | - Robert A Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, USA
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Opedal ØH, Albertsen E, Pérez-Barrales R, Armbruster WS, Pélabon C. No evidence that seed predators constrain pollinator-mediated trait evolution in a tropical vine. AMERICAN JOURNAL OF BOTANY 2019; 106:145-153. [PMID: 30625241 DOI: 10.1002/ajb2.1209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 10/15/2018] [Indexed: 06/09/2023]
Abstract
PREMISE OF THE STUDY Turnover in biotic communities across heterogeneous landscapes is expected to lead to variation in interactions among plants, their mutualists, and their antagonists. Across a fragmented landscape in northern Costa Rica, populations of the euphorb vine Dalechampia scandens vary widely in mating systems and associated blossom traits. Previous work suggested that populations are well adapted to the local reliability of pollination by apid and megachilid bees. We tested whether variation in the intensity of predispersal seed predation by seed weevils in the genus Nanobaris also contributes to the observed variation in blossom traits. METHODS We studied spatiotemporal variation in the relationships between floral advertisement and the probability of seed predation within three focal populations. Then we assessed among-population covariation of predation rate, pollination reliability, mating system, and blossom traits across 20 populations. KEY RESULTS The probability of seed predation was largely unrelated to variation in floral advertisement both within focal populations and among the larger sample of populations. The rate of seed predation was only weakly associated with the rate of cross-pollination (allogamy) in each population but tended to be proportionally greater in populations experiencing less reliable pollination. CONCLUSIONS These results suggest that geographic variation in the intensity of antagonistic interactions have had only minor modifying effects on the evolutionary trajectories of floral advertisement in plant populations in this system. Thus, pollinator-driven floral trait evolution in D. scandens in the study area appears not to be influenced by conflicting seed-predator-mediated selection.
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Affiliation(s)
- Øystein H Opedal
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, NTNU, 7491, Trondheim, Norway
| | - Elena Albertsen
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, NTNU, 7491, Trondheim, Norway
| | - Rocío Pérez-Barrales
- School of Biological Sciences, University of Portsmouth, King Henry Building, King Henry I Street, Portsmouth, PO1 2DY, UK
| | - W Scott Armbruster
- School of Biological Sciences, University of Portsmouth, King Henry Building, King Henry I Street, Portsmouth, PO1 2DY, UK
- Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska, 99775, USA
| | - Christophe Pélabon
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, NTNU, 7491, Trondheim, Norway
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Ezoe H. Excessive flower production as an anti-predator strategy: when is random flower abortion favored? POPUL ECOL 2018. [DOI: 10.1007/s10144-018-0625-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Waser NM, Shaw RG, Price MV. SEED SET AND SEED MASS IN
IPOMOPSIS AGGREGATA
: VARIANCE PARTITIONING AND INFERENCES ABOUT POSTPOLLINATION SELECTION. Evolution 2017; 49:80-88. [DOI: 10.1111/j.1558-5646.1995.tb05960.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/1993] [Accepted: 03/30/1994] [Indexed: 11/27/2022]
Affiliation(s)
- Nickolas M. Waser
- Department of Biology University of California Riverside California 92521
- Rocky Mountain Biological Laboratory Crested Butte Colorado 81224
| | - Ruth G. Shaw
- Rocky Mountain Biological Laboratory Crested Butte Colorado 81224
- Department of Botany and Plant Sciences University of California Riverside California 92521
| | - Mary V. Price
- Department of Biology University of California Riverside California 92521
- Rocky Mountain Biological Laboratory Crested Butte Colorado 81224
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Juenger T, Bergelson J. PAIRWISE VERSUS DIFFUSE NATURAL SELECTION AND THE MULTIPLE HERBIVORES OF SCARLET GILIA,
IPOMOPSIS AGGREGATA. Evolution 2017; 52:1583-1592. [DOI: 10.1111/j.1558-5646.1998.tb02239.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/1997] [Accepted: 06/25/1998] [Indexed: 11/28/2022]
Affiliation(s)
- Thomas Juenger
- Department of Ecology and Evolutionary Biology University of Chicago 1101 East 57th Street Chicago Illinois 60637
- Mountain Research Station University of Colorado 818 County Road 116 Nederland Colorado 80466
| | - Joy Bergelson
- Department of Ecology and Evolutionary Biology University of Chicago 1101 East 57th Street Chicago Illinois 60637
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Song B, Stöcklin J, Gao YQ, Peng DL, Song MS, Sun H. Oviposition by mutualistic seed-consuming pollinators reduces fruit abortion in a recently discovered pollination mutualism. Sci Rep 2016; 6:29886. [PMID: 27418228 PMCID: PMC4945934 DOI: 10.1038/srep29886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 06/23/2016] [Indexed: 11/08/2022] Open
Abstract
A prerequisite for the evolutionary stability of pollinating seed-consuming mutualisms is that each partner benefits from the association. However, few studies of such mutualism have considered the benefit gained by the pollinators. Here, we determined how the pollinating seed-predators ensure the provisioning of their offspring in the recently discovered mutualism between Rheum nobile and Bradysia flies. The correlation between flower fate and fly oviposition was examined. Floral traits and patterns of variation in fruit abortion and fly oviposition were investigated to determine whether female flies exhibit preferences for particular flowers when laying eggs. Indole-3-acetic acid (IAA) was quantified to determine whether female flies manipulate host physiology. Flowers that flies oviposited on had a significantly lower probability of fruit abortion compared with intact flowers. Females did not exhibit oviposition preference for any of the floral traits examined. There was no significant correlation between fruit abortion and fly oviposition in terms of either flower position or timing of flowering. IAA concentrations in oviposited flowers were significantly higher than in intact flowers. Our results suggest that oviposition by the mutualistic seed-consuming pollinator Bradysia sp., greatly reduces the probability of fruit abortion of its host, R. nobile; this may be attributed to the manipulation of host physiology through regulating IAA levels.
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Affiliation(s)
- Bo Song
- Key Laboratory for Plant Diversity and Biogeography of East Asian, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650201, Yunnan, PR China
| | - Jürg Stöcklin
- Institute of Botany, University of Basel, Schönbeinstr 6, Basel 4056, Switzerland
| | - Yong-Qian Gao
- Yunnan Forestry Technological College, 1 Chuanjin Road, Kunming 650224, Yunnan, PR China
| | - De-Li Peng
- Key Laboratory for Plant Diversity and Biogeography of East Asian, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650201, Yunnan, PR China
| | - Min-Shu Song
- Key Laboratory for Plant Diversity and Biogeography of East Asian, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650201, Yunnan, PR China
| | - Hang Sun
- Key Laboratory for Plant Diversity and Biogeography of East Asian, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650201, Yunnan, PR China
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Dutton EM, Shore JS, Frederickson ME. Extrafloral nectar increases seed removal by ants inTurnera ulmifolia. Biotropica 2016. [DOI: 10.1111/btp.12342] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Emily M. Dutton
- Department of Ecology and Evolutionary Biology; University of Toronto; 25 Harbord Street Toronto ON M5S 3G5 Canada
| | - Joel S. Shore
- Department of Biology; York University; 115 Ottawa Road Toronto ON M3J 1P3 Canada
| | - Megan E. Frederickson
- Department of Ecology and Evolutionary Biology; University of Toronto; 25 Harbord Street Toronto ON M5S 3G5 Canada
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Eliyahu D, McCall AC, Lauck M, Trakhtenbrot A. Florivory and nectar-robbing perforations in flowers of pointleaf manzanita Arctostaphylos pungens (Ericaceae) and their effects on plant reproductive success. ARTHROPOD-PLANT INTERACTIONS 2015; 9:613-622. [PMID: 26811740 PMCID: PMC4723111 DOI: 10.1007/s11829-015-9399-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 09/29/2015] [Indexed: 06/05/2023]
Abstract
Damage to petals may have varying effects on the reproductive success of the plant. The variation may depend on the kind of damage to the corolla. Whether the damage is limited to the corolla, as is usually the case with nectar-robbing perforations, or extending to the reproductive parts of the flower, as in the case of florivory holes, might determine the extent of the effect on the plant's reproduction. We examined the various perforations in the flowers of Arctostaphylos pungens and correlated their presence with fruiting success. We found that though florivory holes were highly associated with damage to reproductive parts, fruiting success did not differ significantly between flowers with the two kinds of damage. Although nectar-robbing perforations were not associated with reduced number of fruit produced, they were significantly correlated with reduced number of fruit that contained seemingly viable seeds. The implications of our findings are discussed in the context of pollination and antagonism.
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Affiliation(s)
- Dorit Eliyahu
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA
| | | | - Marina Lauck
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Ana Trakhtenbrot
- Division of Open Areas and Biodiversity, Israeli Ministry of Environmental Protection, Jerusalem, Israel
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Bischoff M, Jürgens A, Campbell DR. Floral scent in natural hybrids of Ipomopsis (Polemoniaceae) and their parental species. ANNALS OF BOTANY 2014; 113:533-44. [PMID: 24355404 PMCID: PMC3906972 DOI: 10.1093/aob/mct279] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 10/15/2013] [Indexed: 05/27/2023]
Abstract
BACKGROUND AND AIMS Floral traits, such as floral volatiles, can contribute to pre-zygotic reproductive isolation by promoting species-specific pollinator foraging. When hybrid zones form, floral traits could also influence post-zygotic isolation. This study examined floral volatiles in parental species and natural hybrids in order to explore potential scent mediation of pre-zygotic and post-zygotic isolation. METHODS Floral bouquets were analysed for the sister species Ipomopsis aggregata and I. tenuituba and their natural hybrids at two contact sites differing in both hybridization rate and temporal foraging pattern of hawkmoth pollinators. Floral volatiles were quantified in diurnal and nocturnal scent samples using gas chromatography-mass spectrometry. KEY RESULTS The bouquets of parental species and hybrids showed qualitative overlap. All flowers emitted similar sets of monoterpenoid, sesquiterpenoid, aliphatic and benzenoid compounds, but separated into groups defined by multivariate analysis of quantitative emissions. The parental species differed most strikingly in the nitrogenous compound indole, which was found almost exclusively in nocturnal bouquets of I. tenuituba. Natural hybrid bouquets were highly variable, and showed emission rates of several compounds that appeared transgressive. However, indole emission rates were intermediate in the hybrids compared with rates in the parents. Volatile bouquets at the contact site with lower hybridization did not show greater species specificity in overall scent emission, but I. tenuituba presented a stronger indole signal during peak hawkmoth activity at that site. CONCLUSIONS The two species of Ipomopsis differed in patterns of floral bouquets, with indole emitted in nocturnal I. tenuituba, but not in I. aggregata. Natural hybrid bouquets were not consistently intermediate between the parents, although hybrids were intermediate in indole emission. The indole signal could potentially serve as a hawkmoth attractant that mediates reproductive isolation both before and after hybrid formation.
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Affiliation(s)
- Mascha Bischoff
- Department of Neurobiology and Behavior, Cornell University, 215 Tower Road, Ithaca, NY 14853, USA
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA
| | - Andreas Jürgens
- University of KwaZulu-Natal, School of Life Sciences, P. Bag X01 Scottsville, Pietermaritzburg 3209, South Africa
| | - Diane R. Campbell
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA
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Pérez-Barrales R, Bolstad GH, Pélabon C, Hansen TF, Armbruster WS. Pollinators and seed predators generate conflicting selection onDalechampiablossoms. OIKOS 2013. [DOI: 10.1111/j.1600-0706.2013.20780.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Weber A, Kolb A. Local plant density, pollination and trait-fitness relationships in a perennial herb. PLANT BIOLOGY (STUTTGART, GERMANY) 2013; 15:335-343. [PMID: 22882317 DOI: 10.1111/j.1438-8677.2012.00645.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Both differences in local plant density and phenotypic traits may affect pollination and plant reproduction, but little is known about how density affects trait-fitness relationships via changes in pollinator activity. In this study we examined how plant density and traits interact to determine pollinator behaviour and female reproductive success in the self-incompatible, perennial herb Phyteuma spicatum. Specifically, we hypothesised that limited pollination service in more isolated plants would lead to increased selection for traits that attract pollinators. We conducted pollinator observations and assessed trait-fitness relationships in a natural population, whose individuals were surrounded by a variable number of inflorescences. Both local plant density and plant phenotypic traits affected pollinator foraging behaviour. At low densities, pollinator visitation rates were low, but increased with increasing inflorescence size, while this relationship disappeared at high densities, where visitation rates were higher. Plant fitness, in terms of seed production per plant and per capsule, was related to both floral display size and flowering time. Seed production increased with increasing inflorescence size and was highest at peak flowering. However, trait-fitness relationships were not density-dependent, and differences in seed production did not appear to be related to differences in pollination. The reasons for this remain unclear, and additional studies are needed to fully understand and explain the observed patterns.
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Affiliation(s)
- A Weber
- Vegetation Ecology and Conservation Biology, Institute of Ecology, University of Bremen, Leobener Strasse, Bremen, Germany.
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Stein K, Templin M, Hensen I, Fischer M, Matthies D, Schleuning M. Negative Effects of Conspecific Floral Density on Fruit Set of Two Neotropical Understory Plants. Biotropica 2012. [DOI: 10.1111/btp.12011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katharina Stein
- Martin-Luther-University Halle-Wittenberg; Institute for Biology/Geobotany and Botanical Garden; Am Kirchtor 1; D-06108; Halle (Saale); Germany
| | - Mathias Templin
- Biodiversity and Climate Research Centre (BiK-F) and Senckenberg Gesellschaft für Naturforschung; Senckenberganlage 25; D-60325; Frankfurt (Main); Germany
| | - Isabell Hensen
- Martin-Luther-University Halle-Wittenberg; Institute for Biology/Geobotany and Botanical Garden; Am Kirchtor 1; D-06108; Halle (Saale); Germany
| | | | - Diethart Matthies
- Department of Biology; Plant Ecology; University of Marburg; Karl-von-Frisch Str. 8; D-35043; Marburg; Germany
| | - Matthias Schleuning
- Biodiversity and Climate Research Centre (BiK-F) and Senckenberg Gesellschaft für Naturforschung; Senckenberganlage 25; D-60325; Frankfurt (Main); Germany
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Zywiec M, Holeksa J, Ledwoń M, Seget P. Reproductive success of individuals with different fruit production patterns. What does it mean for the predator satiation hypothesis? Oecologia 2012; 172:461-7. [PMID: 23080304 PMCID: PMC3655209 DOI: 10.1007/s00442-012-2502-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 10/01/2012] [Indexed: 11/08/2022]
Abstract
The predator satiation hypothesis states that synchronous periodic production of seeds is an adaptive strategy evolved to reduce the pressure of seed predators. The seed production pattern is crucial to the predator satiation hypothesis, but there are few studies documenting the success of individuals that are in synchrony and out of synchrony with the whole population. This study is based on long-term data on seed production of Sorbus aucuparia and specialised pre-dispersal seed predation by Argyresthia conjugella, in a subalpine spruce forest in the Western Carpathians (Poland). At the population level, we tested whether functional and numerical responses of predators to the variation of fruit production operate. At the individual level, we tested whether individuals with higher interannual variability in their own seed crops and higher synchrony with the population have higher percentages of uninfested fruits. The intensity of pre-dispersal seed predation was high (average 70 %; range 19–100 %). There were both functional and numerical responses of predators to the variation of fruit production at the population level. We found that individuals that were expected to be preferred under seed predator pressure had higher reproductive success. With increasing synchrony of fruit production between individual trees and the population, the percentage of infested fruits decreased. There was also a negative relationship between the interannual variation in individual fruit production and the percentage of infested fruits. These results confirm selection for individuals with a masting strategy. However, the population does not seem well adapted to strong seed predation pressure and we suggest that this may be a result of prolonged diapause of A. conjugella.
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Affiliation(s)
- Magdalena Zywiec
- Institute of Botany, Polish Academy of Sciences, ul. Lubicz 46, 31-512, Kraków, Poland.
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Burkhardt A, Ridenhour BJ, Delph LF, Bernasconi G. The contribution of a pollinating seed predator to selection on Silene latifolia females. J Evol Biol 2011; 25:461-72. [PMID: 22168583 DOI: 10.1111/j.1420-9101.2011.02436.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Interactions, antagonistic or mutualistic, can exert selection on plant traits. We explored the role of Hadena bicruris, a pollinating seed predator, as a selective agent on its host, the dioecious plant Silene latifolia. We exposed females from artificial-selection lines (many, small flowers (SF) vs. few, large flowers (LF)) to this moth. Infestation did not differ significantly between lines, but the odds of attacked fruits aborting were higher in SF females. We partitioned selection between that caused by moth attack and that resulting from all other factors. In both lines, selection via moth attack for fewer, smaller flowers contrasted with selection via other factors for more flowers. In LF females, selection via the two components was strongest and selection via moth attack also favoured increased fruit abortion. This suggests that the moths act as more of a selective force on flower size and number via their predating than their pollinating role.
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Affiliation(s)
- A Burkhardt
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
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20
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Irwin RE, Brody AK. Additive effects of herbivory, nectar robbing and seed predation on male and female fitness estimates of the host plant Ipomopsis aggregata. Oecologia 2011; 166:681-92. [DOI: 10.1007/s00442-010-1898-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2009] [Accepted: 12/14/2010] [Indexed: 11/24/2022]
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21
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Rosas-Guerrero V, Quesada M, Armbruster WS, Pérez-Barrales R, Smith SD. INFLUENCE OF POLLINATION SPECIALIZATION AND BREEDING SYSTEM ON FLORAL INTEGRATION AND PHENOTYPIC VARIATION IN IPOMOEA. Evolution 2010; 65:350-64. [DOI: 10.1111/j.1558-5646.2010.01140.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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22
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Herrera J. Visibility vs. biomass in flowers: exploring corolla allocation in Mediterranean entomophilous plants. ANNALS OF BOTANY 2009; 103:1119-27. [PMID: 19258340 PMCID: PMC2707908 DOI: 10.1093/aob/mcp046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND AIMS While pollinators may in general select for large, morphologically uniform floral phenotypes, drought stress has been proposed as a destabilizing force that may favour small flowers and/or promote floral variation within species. METHODS The general validity of this concept was checked by surveying a taxonomically diverse array of 38 insect-pollinated Mediterranean species. The interplay between fresh biomass investment, linear size and percentage corolla allocation was studied. Allometric relationships between traits were investigated by reduced major-axis regression, and qualitative correlates of floral variation explored using general linear-model MANOVA. KEY RESULTS Across species, flowers were perfectly isometrical with regard to corolla allocation (i.e. larger flowers were just scaled-up versions of smaller ones and vice versa). In contrast, linear size and biomass varied allometrically (i.e. there were shape variations, in addition to variations in size). Most floral variables correlated positively and significantly across species, except corolla allocation, which was largely determined by family membership and floral symmetry. On average, species with bilateral flowers allocated more to the corolla than those with radial flowers. Plant life-form was immaterial to all of the studied traits. Flower linear size variation was in general low among conspecifics (coefficients of variation around 10 %), whereas biomass was in general less uniform (e.g. 200-400 mg in Cistus salvifolius). Significant among-population differences were detected for all major quantitative floral traits. CONCLUSIONS Flower miniaturization can allow an improved use of reproductive resources under prevailingly stressful conditions. The hypothesis that flower size reflects a compromise between pollinator attraction, water requirements and allometric constraints among floral parts is discussed.
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ABDALA-ROBERTS LUIS, PARRA-TABLA VÍCTOR, SALINAS-PEBA LUIS, HERRERA CARLOSM. Noncorrelated effects of seed predation and pollination on the perennial herb Ruellia nudiflora remain spatially consistent. Biol J Linn Soc Lond 2009. [DOI: 10.1111/j.1095-8312.2008.01170.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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24
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ZHANG YW, YANG CF, ZHAO JM, GUO YH. Selective nectar robbing in a gynodioecious plant (Glechoma longituba) enhances female advantage. J Evol Biol 2009; 22:527-35. [DOI: 10.1111/j.1420-9101.2008.01669.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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25
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Segraves KA. FLORIVORES LIMIT COST OF MUTUALISM IN THE YUCCA–YUCCA MOTH ASSOCIATION. Ecology 2008; 89:3215-3221. [DOI: 10.1890/07-1993.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 03/05/2008] [Accepted: 03/17/2008] [Indexed: 11/18/2022]
Affiliation(s)
- Kari A. Segraves
- Department of Biology, Syracuse University, 130 College Place, Syracuse, New York 13244 USA
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Francisco MR, Lunardi VO, Guimarães PR, Galetti M. Factors affecting seed predation of Eriotheca gracilipes (Bombacaceae) by parakeets in a cerrado fragment. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2008. [DOI: 10.1016/j.actao.2007.11.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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27
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ANDERSSON STEFAN. Fitness consequences of floral variation in Senecio jacobaea (Asteraceae): evidence from a segregating hybrid population and a resource manipulation experiment. Biol J Linn Soc Lond 2008. [DOI: 10.1111/j.1095-8312.2001.tb01373.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Brody AK, Irwin RE, McCutcheon ML, Parsons EC. Interactions between nectar robbers and seed predators mediated by a shared host plant, Ipomopsis aggregata. Oecologia 2007; 155:75-84. [PMID: 17965889 DOI: 10.1007/s00442-007-0879-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Accepted: 09/29/2007] [Indexed: 05/25/2023]
Abstract
Animals that consume plant parts or rewards but provide no services in return are likely to have significant impacts on the reproductive success of their host plants. The effects of multiple antagonists to plant reproduction may not be predictable from studying their individual effects in isolation. If consumer behaviors are contingent on each other, such interactions may limit the ability of the host to evolve in response to any one enemy. Here, we asked whether nectar robbing by a bumblebee (Bombus occidentalis) altered the likelihood of pre-dispersal seed predation by a fly (Hylemya sp.) on a shared host plant, Ipomopsis aggregata (Polemoniaceae). We estimated the fitness consequences of the combined interactions using experimental manipulations of nectar robbing within and among sites. Within sites, nectar robbing reduced the percentage of fruits destroyed by Hylemya. However, the negative effects of robbing on seed production outweighed any advantages associated with decreased seed predation in robbed plants. We found similar trends among sites when we manipulated robbing to all plants within a local population, although the results were not statistically significant. Taken together, our results suggest that seed predation is not independent of nectar robbing. Thus, accounting for the interactions among species is crucial to predicting their ecological effects and plant evolutionary response.
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Affiliation(s)
- Alison K Brody
- Department of Biology, University of Vermont, Burlington, VT 05405, USA.
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29
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Sandring S, Riihimäki MA, Savolainen O, Agren J. Selection on flowering time and floral display in an alpine and a lowland population of Arabidopsis lyrata. J Evol Biol 2007; 20:558-67. [PMID: 17305822 DOI: 10.1111/j.1420-9101.2006.01260.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
To determine whether population differentiation in flowering time is consistent with differences in current selection, we quantified phenotypic selection acting through female reproductive success on flowering phenology and floral display in two Scandinavian populations of the outcrossing, perennial herb Arabidopsis lyrata in two years. One population was located in an alpine environment strongly affected by grazing, whereas the other was close to sea level and only moderately affected by herbivory. Multiple regression models indicated directional selection for early end of flowering in one year in the lowland population, and directional selection for early start of flowering in one year in the alpine population. As expected, there was selection for more inflorescences in the lowland population. However, in the alpine population, plants with many inflorescences were selectively grazed and the number of inflorescences produced was negatively related to female fitness in one year and not significantly related to female fitness in the second year. The results are consistent with the hypothesis that genetic differentiation in flowering phenology between the study populations is adaptive, and indicate that interactions with selective grazers may strongly influence selection on floral display in A. lyrata.
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Affiliation(s)
- S Sandring
- Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
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Pohl N, Carvallo G, Botto-Mahan C, Medel R. Nonadditive effects of flower damage and hummingbird pollination on the fecundity of Mimulus luteus. Oecologia 2006; 149:648-55. [PMID: 16896778 DOI: 10.1007/s00442-006-0479-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Accepted: 05/31/2006] [Indexed: 10/24/2022]
Abstract
Flower herbivory and pollination have been described as interactive processes that influence each other in their effects on plant reproductive success. Few studies, however, have so far examined their joint effects in natural populations. In this paper we evaluate the influence of flower damage and pollination by the hummingbird Oreotrochilus leucopleurus on the fecundity of the Andean monkey flower Mimulus luteus. We performed a 2x2 factorial experiment, with artificial clipping of lower petals and selective exclusion of the hummingbird as main factors. In spite of the relatively low proportion (27.5%) of the variance in seed production accounted for by the full factorial model, artificial damage and hummingbird exclusion, as well as their interaction, were highly significant, indicating nonadditive effects of factors on plant fecundity. In the presence of hummingbirds, undamaged flowers had a seed production that was 1.7-fold higher than for damaged flowers, suggesting that the effect of flower damage on female reproductive success occurs probably as a consequence of hummingbird discrimination against damaged corollas. This result indicates that the impact of flower herbivory on plant fecundity was contingent on the presence or absence of hummingbirds, suggesting that pollinators may indirectly select for undamaged and probably resistant flower phenotypes. A second interaction effect revealed that undamaged flowers produced 78.5% more seeds in the absence of rather than in the presence of O. leucopleurus, raising the question of the ecological mechanism involved. We suggest that the strong territorial behavior exhibited by the bee Centris nigerrima may confine the foraging activities of the remaining bee species to safe sites within exclosures. Overall, our results provide evidence that hummingbird pollination and flower herbivory have interdependent effects on M. luteus fecundity, which indicates that it will be difficult to predict their ecological and evolutionary consequences unless interactions are analyzed in an integrated form.
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Affiliation(s)
- Nélida Pohl
- Department of Ecology and Evolutionary Biology, 321 Steinhaus Hall, University of California, Irvine, CA 92697-2525, USA
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32
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Andersson S. Experimental demonstration of floral allocation costs in Crepis tectorum. ACTA ACUST UNITED AC 2006. [DOI: 10.1139/b06-041] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Information on floral resource costs is fundamental for understanding how selection operates on floral morphology. In this study, I explored the cost of maturing flowers in a self-incompatible population of the ligulate composite Crepis tectorum L. by experimentally manipulating floral investment and then monitoring the response in reproductive effort. Plants on which the heads were removed during the initial stage of ligule expansion had a higher reproductive effort than plants whose heads were removed immediately after flower maturation, and the latter plants had a higher reproductive effort than plants on which all flowers were permitted to set fruit. Judging from biomass estimates and the magnitude of the observed tradeoffs, the amount of resources allocated to maturing flowers was about half as great as the amount of resources devoted to fruit maturation. These and other results suggest that floral tradeoffs may exert negative selection on floral size variables.
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Affiliation(s)
- Stefan Andersson
- Plant Ecology and Systematics, Department of Ecology, University of Lund, Sölvegatan 37, S-223 62 Lund, Sweden
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33
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Jorgensen TH, Andersson S. Evolution and maintenance of pollen-colour dimorphisms in Nigella degenii: habitat-correlated variation and morph-by-environment interactions. THE NEW PHYTOLOGIST 2005; 168:487-98. [PMID: 16219087 DOI: 10.1111/j.1469-8137.2005.01525.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Dimorphism in pollen colour is rare among flowering plants, but occurs in two geographically and morphologically distinct subspecies of Nigella degenii (Ranunculaceae). We evaluated the role of genotype-by-environment interactions in the maintenance of two pollen morphs within each of these subspecies. Morph frequencies in a number of populations were related to current habitat conditions, and an extensive common-garden experiment involving both optimal and stressful conditions (drought and nutrient deficiency) was carried out. The putatively derived (dark) pollen morph of N. degenii ssp. barbro has a higher frequency on slopes facing north or east than on slopes facing south or west. Plants of the dark morph also have a higher mortality under drought stress or nutrient deficiency. Data available for N. degenii ssp. jenny provide little evidence for habitat-correlated variation in morph frequency or morph-specific differences in fitness under optimal and stressful growth conditions. Our results suggest that morph-by-environment interactions in mortality could contribute to the maintenance of pollen-colour dimorphisms in N. degenii ssp. barbro.
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Strauss SY, Sahli H, Conner JK. Toward a more trait-centered approach to diffuse (co)evolution. THE NEW PHYTOLOGIST 2005; 165:81-89. [PMID: 15720623 DOI: 10.1111/j.1469-8137.2004.01228.x] [Citation(s) in RCA: 154] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
How species evolve depends on the communities in which they are embedded. Here, we briefly review the ideas underlying concepts of diffuse coevolution, evolution, and selection. We discuss criteria to identify when evolution will be diffuse. We advocate a more explicitly trait-oriented approach to diffuse (co)evolution, and discuss how considering effects of interacting species on fitness alone tells us little about evolution. We endorse the view that diffuse evolution occurs whenever the response to selection by one interacting species on a given trait is altered by the presence of a second interacting species. Building on the work of others, we clarify and expand the criteria for diffuse evolution and present a simple experimental design that will allow the detection of diffuse selection. We argue that a greater focus on selection on specific traits and the evolutionary response to that selection will improve our conceptual understanding of how communities affect the evolution of species embedded within them.
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Affiliation(s)
- Sharon Y Strauss
- Section of Evolution and Ecology, One Shields Ave, 2320 Storer Hall, UC, Davis, CA 95616, USA.
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35
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Scarlet gilia resistance to insect herbivory: the effects of early season browsing, plant apparency, and phytochemistry on patterns of seed fly attack. Evol Ecol 2005. [DOI: 10.1007/s10682-004-8090-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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36
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Strauss SY, Irwin RE. Ecological and Evolutionary Consequences of Multispecies Plant-Animal Interactions. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2004. [DOI: 10.1146/annurev.ecolsys.35.112202.130215] [Citation(s) in RCA: 402] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sharon Y. Strauss
- Section in Evolution and Ecology and Center for Population Biology, University of California, Davis, California 95616;
| | - Rebecca E. Irwin
- Institute of Ecology, University of Georgia, Athens, Georgia 30602;
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Castellanos MC, Wilson P, Thomson JD. 'Anti-bee' and 'pro-bird' changes during the evolution of hummingbird pollination in Penstemon flowers. J Evol Biol 2004; 17:876-85. [PMID: 15271088 DOI: 10.1111/j.1420-9101.2004.00729.x] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Floral phenotypes may be as much the result of selection for avoidance of some animal visitors as selection for improving the interaction with better pollinators. When specializing on hummingbird-pollination, Penstemon flowers may have evolved to improve the morphological fit between bird and flower, or to exclude less-efficient bees, or both. We hypothesized how such selection might work on four floral characters that affect the mechanics of pollen transfer: anther/stigma exsertion, presence of a lower corolla lip, width of the corolla tube, and angle of flower inclination. We surgically modified bee-pollinated P. strictus flowers changing one trait at a time to make them resemble hummingbird-pollinated P. barbatus flowers, and measured pollen transfer by bumblebees and hummingbirds. Results suggest that, apart from 'pro-bird' adaptations, specific 'anti-bee' adaptations have been important in shaping hummingbird-flowers. Moreover, some trait changes may have been selected for only if changing in concert with other traits.
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Affiliation(s)
- M C Castellanos
- Department of Zoology, University of Toronto, Toronto, Canada.
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38
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Cariveau D, Irwin RE, Brody AK, Garcia-Mayeya LS, von der Ohe A. Direct and indirect effects of pollinators and seed predators to selection on plant and floral traits. OIKOS 2004. [DOI: 10.1111/j.0030-1299.2004.12641.x] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Herrera CM, Medrano M, Rey PJ, Sanchez-Lafuente AM, Garcia MB, Guitian J, Manzaneda AJ. Interaction of pollinators and herbivores on plant fitness suggests a pathway for correlated evolution of mutualism- and antagonism-related traits. Proc Natl Acad Sci U S A 2002; 99:16823-8. [PMID: 12482948 PMCID: PMC139228 DOI: 10.1073/pnas.252362799] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2002] [Indexed: 11/18/2022] Open
Abstract
Different kinds of plant-animal interactions are ordinarily studied in isolation, yet considering the combined fitness effects of mutualistic and antagonistic interactions is essential to understanding plant character evolution. Functional, structural, or phylogenetic associations between attractive and defensive traits may be nonadaptive or result from correlational selection on sets of herbivory- and pollination-linked traits. Nonadditivity of fitness effects of mutualists and antagonists, a requisite for correlational selection, was experimentally tested in the field. We created experimental populations of the insect-pollinated perennial herb, Helleborus foetidus, at 16 different locations distributed among three regions in the Iberian Peninsula. Plants experienced one of four possible selective regimes generated by independently weakening the effects of pollinators and herbivores (flower and fruit predators) according to a two-way fully factorial design. Effects were assessed in terms of number of next-generation offspring recruited per mother plant under natural field conditions. Differences among H. foetidus plants in the strength of their interactions with pollinators and herbivores translated into differential fitness, as measured in terms of recruited offspring, and subsequent changes in plant population densities. A strong, geographically consistent nonadditivity in the fitness consequences of pollinators and herbivores was found also. Plants possessing the particular combination of "traits" simultaneously enhancing pollination and escape from herbivores enjoyed a disproportionate fitness advantage over plants possessing any of the other three possible "trait" combinations. Results suggest a simple, possibly widespread ecological pathway favoring the adaptive correlated evolution of mutualism- and antagonism-related plant traits in pollinator-dependent plants suffering intense flower and fruit herbivory.
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Affiliation(s)
- Carlos M Herrera
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Cientificas, Avenida de Maria Luisa sn, E-41013 Sevilla, Spain.
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Irwin RE, Dorsett B. Volatile production by buds and corollas of two sympatric, confamilial plants, Ipomopsis aggregata and Polemonium foliosissimum. J Chem Ecol 2002; 28:565-78. [PMID: 11944833 DOI: 10.1023/a:1014596129601] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We used solid-phase microextraction of headspace samples followed by gas chromatography and mass spectrometry to identify and quantify the major volatile compounds produced by the buds and corollas of Ipomopsis aggregata (Polemoniaceae), and we compared them to a sympatric, confamilial plant species, Polemonium foliosissimum. The two species have distinct floral morphologies and pollinators, but share a common predispersal seed predator that oviposits under the calyces of buds. Ipomopsis aggregata buds emitted fewer compounds than the corollas. The buds of I. aggregata were dominated by alpha-pinene and, to a lesser extent, beta-pinene. The corollas of I. aggregata emitted a mixture of 10 compounds. Like the buds, I. aggregata corollas produced relatively high concentrations of alpha-pinene as well as caryophyllene. In addition, the emission of four terpenoids, three esters, and one ketone added to the volatile bouquet of the corollas. Polemonium foliosissimum buds also emitted fewer compounds than the corollas. The buds of P. foliosissimum were dominated by beta-pinene and, to a lesser extent, alpha-pinene. The corollas of P. foliosissimum were also dominated by beta-pinene along with three terpenoids, three alcohols, one ester, and two aldehydes. Comparing I. aggregata and P. foliosissimum, bud samples from both species produced considerable amounts of alpha- and beta-pinene. Ipomopsis aggregata emitted more alpha-pinene than beta-pinene, while P. foliosissimum emitted more beta-pinene. The corollas of the two species, however, differed in their volatile bouquet. The partition of volatiles between I. aggregata and P. foliosissimum buds and corollas and differences in volatile production between I. aggregata and P. foliosissimum are consistent with selection pressures exerted by organisms interacting with these plants.
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Affiliation(s)
- Rebecca E Irwin
- Insitute of Ecology, University of Georgia, Athens 30602, USA.
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Galen C, Cuba J. Down the tube: pollinators, predators, and the evolution of flower shape in the alpine skypilot, Polemonium viscosum. Evolution 2001; 55:1963-71. [PMID: 11761057 DOI: 10.1111/j.0014-3820.2001.tb01313.x] [Citation(s) in RCA: 161] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We address how a conflict between pollinator attraction and avoidance of flower predation influences the evolution of flower shape in Polemonium viscosum. Flower shape in P. viscosum is the product of an isometric relationship between genetically correlated (rA = 0.70) corolla flare and length. Bumblebee pollinators preferentially visit flowers that are more flared and have longer tubes, selecting for a funnel-shaped corolla. However, flower shape also influences nectar-foraging ants that sever the style at its point of attachment to the ovary. Surveys of ant damage show that plants having flowers with flared, short corollas are most vulnerable to ant predation. Consistent with this result, the ratio of corolla length to flare is significantly greater in a krummholz (high predation risk) population than in a tundra (low predation risk) population. To explicitly test whether the evolution of a better defended flower would exact a cost in pollination, we created tubular flowers by constricting the corolla during development. Performance of tubular flowers and natural controls was compared for defensive and attractive functions. In choice trials, ants entered control flowers significantly more often than tubular ones, confirming that the evolution of tubular flowers would reduce the risk of predation. However, in a bumblebee-pollinated population, tubular flowers received significantly less pollen and set fewer seeds than controls. A fitness model incorporating these data predicts that in the absence of the genetic correlation between corolla length and flare, intermittent selection for defense could allow tubular flowers to spread in the krummholz population. However, in the tundra, where bumblebees account for nearly all pollination, the model predicts that tubular flowers should always confer a fitness disadvantage.
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Affiliation(s)
- C Galen
- Division of Biological Sciences, University of Missouri, Columbia 65211, USA.
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Galen C, Cuba J. DOWN THE TUBE: POLLINATORS, PREDATORS, AND THE EVOLUTION OF FLOWER SHAPE IN THE ALPINE SKYPILOT, POLEMONIUM VISCOSUM. Evolution 2001. [DOI: 10.1554/0014-3820(2001)055[1963:dttppa]2.0.co;2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
44
|
|
45
|
|
46
|
|
47
|
|
48
|
|
49
|
|
50
|
Nakamura RR, Mitchell-Olds T, Manasse RS, Lello D. Seed predation, pathogen infection and life-history traits in Brassica rapa. Oecologia 1995; 102:324-328. [PMID: 28306843 DOI: 10.1007/bf00329799] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/1994] [Accepted: 12/20/1994] [Indexed: 10/26/2022]
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