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Beck JJ, McKone MJ, Wagenius S. Masting, fire-stimulated flowering, and the evolutionary ecology of synchronized reproduction. Ecology 2024; 105:e4261. [PMID: 38363004 DOI: 10.1002/ecy.4261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 12/27/2023] [Indexed: 02/17/2024]
Abstract
Synchronized episodic reproduction among long-lived plants shapes ecological interactions, ecosystem dynamics, and evolutionary processes worldwide. Two active scientific fields investigate the causes and consequences of such synchronized reproduction: the fields of masting and fire-stimulated flowering. While parallels between masting and fire-stimulated flowering have been previously noted, there has been little dialogue between these historically independent fields. We predict that the synthesis of these fields will facilitate new insight into the causes and consequences of synchronized reproduction. Here we briefly review parallels between masting and fire-stimulated flowering, using two case studies and a database of 1870 plant species to facilitate methodological, conceptual, geographical, taxonomic, and phylogenetic comparisons. We identify avenues for future research and describe three key opportunities associated with synthesis. First, the taxonomic and geographic complementarity of empirical studies from these historically independent fields highlights the potential to derive more general inferences about global patterns and consequences of synchronized reproduction in perennial plants. Second, masting's well developed conceptual framework for evaluating adaptive hypotheses can help guide empirical studies of fire-stimulated species and enable stronger inferences about the evolutionary ecology of fire-stimulated flowering. Third, experimental manipulation of reproductive variation in fire-stimulated species presents unique opportunities to empirically investigate foundational questions about ecological and evolutionary processes underlying synchronized reproduction. Synthesis of these fields and their complementary insights offers a unique opportunity to advance our understanding of the evolutionary ecology of synchronized reproduction in perennial plants.
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Affiliation(s)
- Jared J Beck
- Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, Glencoe, Illinois, USA
| | - Mark J McKone
- Department of Biology, Carleton College, Northfield, Minnesota, USA
| | - Stuart Wagenius
- Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, Glencoe, Illinois, USA
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2
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Song Y, Liu L, Ouyang F, Cui H, Guo W, Lv S, Ye B, Li L, Yu Y, Men X. Cold storage alters the fat-trehalose trade-off, decreases the flight ability, and maintains the high survival rate and flight speed of Osmia excavata (Hymenoptera: Megachilidae). Insect Sci 2023. [PMID: 37822224 DOI: 10.1111/1744-7917.13276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/18/2023] [Accepted: 08/27/2023] [Indexed: 10/13/2023]
Abstract
Osmia solitary bees are important pollinators of various crops worldwide. Refrigeration has been widely used to synchronize the emergence time of Osmia species from cocoons with the blooming time of different crops, but the fitness of Osmia after refrigeration remains unknown. Here, the effects of long-term refrigeration at 0 °C on the vitality, flight ability, and metabolism of Osmia excavata, which is known as the "king of pollination" in China, were studied. The survival rate (>90% before 120 d), weight loss rate (<15% after 170 d), and mean flight speed of O. excavata were not greatly affected after long-term refrigeration. The content of fats, which have antifreeze and energy storage properties, was not significantly altered in O. excavata before 130 d of refrigeration, which might explain why the survival rates and flight speed of O. excavata remained high after long-term refrigeration. However, the flight duration and distance decreased significantly (P < 0.05), and both were positively correlated with the reduced trehalose levels in O. excavata (r = [+0.69] - [+0.71]; P < 0.05). Overall, these findings indicate that the pollination potential of O. excavata for various crops with different flowering periods is high after long-term refrigeration; however, long-term refrigeration may decrease pollination efficiency. Our findings highlight new research directions that could improve the ecological service function of refrigerated O. excavata.
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Affiliation(s)
- Yingying Song
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Li Liu
- College of Plant Protection, Shandong Agricultural University, Jinan, China
| | - Fang Ouyang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Hongying Cui
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Wenxiu Guo
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Suhong Lv
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Baohua Ye
- College of Plant Protection, Shandong Agricultural University, Jinan, China
| | - Lili Li
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Yi Yu
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Xingyuan Men
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
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3
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Weinman LR, Ress T, Gardner J, Winfree R. Individual bee foragers are less efficient transporters of pollen for the plants from which they collect the most pollen into their scopae. Am J Bot 2023. [PMID: 37163647 DOI: 10.1002/ajb2.16178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
PREMISE Bees provision most of the pollen they remove from anthers to their larvae and transport only a small proportion to stigmas, which can negatively affect plant fitness. Though most bee species collect pollen from multiple plant species, we know little about how the efficiency of bees' pollen transport varies among host plant species, or how it relates to other aspects of generalist bee foraging behavior that benefit plant fitness, such as specialization on individual foraging bouts. METHODS We compared the pollen collected and transported by three bee species for 46 co-occurring plant species. Specifically, we compared the relative abundance of pollen taxa in individual bees' scopae, structures where bees store pollen to provision larvae, with the relative abundance of pollen taxa on the rest of bees' bodies, which is more likely to be transferred to stigmas. RESULTS Bees carried five times more pollen grains in their scopae than elsewhere on their bodies. Within foraging bouts, bees were relatively specialized in their pollen collection, but transported proportionally less pollen for the host plants on which they specialized. Across foraging bouts, two bee species transported proportionally less pollen for some of their host plants than for others, though differences didn't consistently follow the same trend as at the foraging bout scale. CONCLUSIONS Our results suggest that foraging bout specialization, which is known to reduce heterospecific pollen transfer, also results in less efficient pollen transport. Thus, bee foragers that visit predominantly one plant species may have contrasting effects on that plant's fitness. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Lucia R Weinman
- Graduate Program in Ecology & Evolution, 14 College Farm Road, Rutgers University, New Brunswick, 08901, NJ, USA
- Department of Ecology, Evolution & Natural Resources, Rutgers University, New Brunswick, 08901, New Jersey, USA
| | - Trent Ress
- Department of Ecology, Evolution & Natural Resources, Rutgers University, New Brunswick, 08901, New Jersey, USA
| | - Joel Gardner
- Department of Entomology, University of Manitoba, Winnipeg, R3T 2N2, MB, Canada
| | - Rachael Winfree
- Department of Ecology, Evolution & Natural Resources, Rutgers University, New Brunswick, 08901, New Jersey, USA
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4
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Burgin GA, Bronzo-Munich O, Garner AG, Acevedo IA, Hopkins R. Characterizing each step of pollination in Phlox drummondii reveals a single butterfly species predominates the pollinator assemblage. Am J Bot 2023; 110:e16172. [PMID: 37087740 DOI: 10.1002/ajb2.16172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 03/17/2023] [Accepted: 03/19/2023] [Indexed: 05/03/2023]
Abstract
PREMISE A central goal of pollination biology is to connect plants with the identity of their pollinator(s). While predictions based on floral syndrome traits are extremely useful, direct observation can reveal further details of a species' pollination biology. The wildflower, Phlox drummondii, has a floral syndrome consistent with Lepidoptera pollination. We test this prediction using empirical data. METHODS We observe each step of pollination in P. drummondii. First, we observe 55.5 hours of floral visitation across the species range. We use temporal pollinator exclusion to determine the contribution of diurnal and nocturnal pollination to reproductive output. We then quantify P. drummondii pollen transfer by the dominant floral visitor, Battus philenor. Finally, we test the effect of B. philenor visitation on P. drummondii reproduction by quantifying fruit set following single pollinator visits. RESULTS B. philenor is the primary pollinator of P. drummondii. Pollination is largely diurnal, and we observe a variety of lepidopteran visitors during this period. However, B. philenor is the most frequent visitor, representing 88.5% of all observed visits. We show that B. philenor is an extremely common visitor and also an effective pollinator by demonstrating that individuals transfer pollen between flowers and that a single visit can elicit fruit set. CONCLUSION Our data are consistent with the prediction of lepidopteran pollination and further reveal a single butterfly species, B. philenor, as the primary pollinator. Our study demonstrates the importance of empirical pollinator observations, adds to our understanding of pollination mechanics, and offers a specific case study of butterfly pollination. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Grace A Burgin
- Department of Organismic and Evolutionary Biology, The Arnold Arboretum, Harvard University, Cambridge, MA, 021382, USA
| | - Olivia Bronzo-Munich
- Department of Organismic and Evolutionary Biology, The Arnold Arboretum, Harvard University, Cambridge, MA, 021382, USA
| | - Austin G Garner
- Department of Organismic and Evolutionary Biology, The Arnold Arboretum, Harvard University, Cambridge, MA, 021382, USA
| | - Izzy A Acevedo
- Department of Organismic and Evolutionary Biology, The Arnold Arboretum, Harvard University, Cambridge, MA, 021382, USA
| | - Robin Hopkins
- Department of Organismic and Evolutionary Biology, The Arnold Arboretum, Harvard University, Cambridge, MA, 021382, USA
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5
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Gross K, Undin M, Thompson JN, Friberg M. Components of local adaptation and divergence in pollination efficacy in a coevolving species interaction. Ecology 2023:e4043. [PMID: 36976166 DOI: 10.1002/ecy.4043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 02/15/2023] [Accepted: 03/14/2023] [Indexed: 03/29/2023]
Abstract
Selection leading to adaptation to interactions may generate rapid evolutionary feedbacks and drive diversification of species interactions. The challenge is to understand how the many traits of interacting species combine to shape local adaptation in ways directly or indirectly resulting in diversification. We used the well-studied interactions between Lithophragma plants (Saxifragaceae) and Greya moths (Prodoxidae) to evaluate how plants and moths together contribute to local divergence in pollination efficacy. Specifically, we studied L. bolanderi and its two specialized Greya moth pollinators in two contrasting environments in the Sierra Nevada, California. Both moths pollinate L. bolanderi during nectaring, and one of them - G. politella - also while ovipositing through the floral corolla into the ovary. Firstly, field surveys of floral visitors and the presence of G. politella eggs and larvae in developing capsules showed that one population is visited only by G. politella and few other pollinators, whereas the other is visited by both Greya species and other pollinators. Secondly, L. bolanderi in these two natural populations differed in several floral traits putatively important for pollination efficacy. Thirdly, laboratory experiments with greenhouse-grown plants and field-collected moths showed that L. bolanderi is more efficiently pollinated by local compared to non-local nectaring moths of both species. Pollination efficacy of ovipositing G. politella was also higher for local moths for the L. bolanderi population that relies more heavily on this species in nature. Finally, time-lapse photography in the laboratory showed that G. politella from different populations differ in oviposition behavior, suggesting the potential for local adaptation also among Greya populations. Collectively, our results are a rare example of components of local adaptation contributing to divergence in pollination efficiency in a coevolving interaction and, thus, provide insights into how geographic mosaics of coevolution may lead to coevolutionary diversification in species interactions. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Karin Gross
- Department of Plant Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, 752 36, Sweden
- Department of Biology, Lund University, Lund, 223 62, Sweden
- Department of Environment and Biodiversity, Paris Lodron University Salzburg, Salzburg, 5020, Austria
| | - Malin Undin
- Department of Plant Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, 752 36, Sweden
- Department of Natural Sciences, Mid Sweden University, Sundsvall, 851 70, Sweden
| | - John N Thompson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, 95060, USA
| | - Magne Friberg
- Department of Plant Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, 752 36, Sweden
- Department of Biology, Lund University, Lund, 223 62, Sweden
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6
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Waterman R, Sahli H, Koelling VA, Karoly K, Conner JK. Strong evidence for positive and negative correlational selection revealed by recreating ancestral variation. Evolution 2023; 77:264-275. [PMID: 36622224 DOI: 10.1093/evolut/qpac001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 09/27/2022] [Accepted: 10/06/2022] [Indexed: 01/10/2023]
Abstract
The study of adaptation helps explain biodiversity and predict future evolution. Yet the process of adaptation can be difficult to observe due to limited phenotypic variation in contemporary populations. Furthermore, the scarcity of male fitness estimates has made it difficult to both understand adaptation and evaluate sexual conflict hypotheses. We addressed both issues in our study of two anther position traits in wild radish (Raphanus raphanistrum): anther exsertion (long filament - corolla tube lengths) and anther separation (long - short filament lengths). These traits affect pollination efficiency and are particularly interesting due to the unusually high correlations among their component traits. We measured selection through male and female fitness on wild radish plants from populations artificially selected to recreate ancestral variation in each anther trait. We found little evidence for conflicts between male and female function. We found strong evidence for stabilizing selection on anther exsertion and disruptive selection on anther separation, indicating positive and negative correlational selection on the component traits. Intermediate levels of exsertion are likely an adaptation to best contact small bees. The function of anther separation is less clear, but future studies might investigate pollen placement on pollinators and compare species possessing multiple stamen types.
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Affiliation(s)
- Robin Waterman
- Kellogg Biological Station and Department of Plant Biology, Michigan State University, Hickory Corners, MI, United States
| | - Heather Sahli
- Kellogg Biological Station and Department of Plant Biology, Michigan State University, Hickory Corners, MI, United States.,Department of Biology, Shippensburg University, Shippensburg, PA 17257, United States
| | - Vanessa A Koelling
- Biology Department, Reed College, Portland, OR, United States.,Current Address: Department of Biology and Environmental Science, Auburn University at Montgomery, Montgomery, AL, United States
| | - Keith Karoly
- Biology Department, Reed College, Portland, OR, United States
| | - Jeffrey K Conner
- Kellogg Biological Station and Department of Plant Biology, Michigan State University, Hickory Corners, MI, United States
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7
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Stewart AB, Diller C, Dudash MR, Fenster CB. Pollination-precision hypothesis: support from native honey bees and nectar bats. New Phytol 2022; 235:1629-1640. [PMID: 35194792 DOI: 10.1111/nph.18050] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/09/2022] [Indexed: 05/28/2023]
Abstract
The evolution of floral traits is often considered to reflect selection for increased pollination efficiency. Known as the pollination-precision hypothesis, increased pollination efficiency is achieved by enhancing pollen deposition on precise areas of the pollinator. Most research to date addressing this hypothesis has examined plant species that are a priori predicted to place pollen precisely, but we still lack comparisons with species predicted to have low pollination efficiency. We studied 39 plant species with diverse floral morphologies and measured the precision of pollen placement on two pollinator groups: honey bees (genus Apis) and nectar bats (family Pteropodidae). Pollen was collected from four locations of each pollinator's body (bees: dorsal thorax, ventral thorax, dorsal abdomen, ventral abdomen; bats: crown, face, chest, wing) to calculate pollen placement precision using Pielou's evenness index. We also quantified variation in floral design by scoring floral symmetry, corolla fusion, floral orientation and stamen number. We confirm the importance of four floral character states (bilateral symmetry, fused corollas, horizontal orientation and reduced stamen number) in promoting precise pollen placement on diverse pollinators. Our findings provide phylogenetically corrected, empirical support that the evolution of the four floral characters reflect selection for enhanced precision of pollen placed on pollinators.
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Affiliation(s)
- Alyssa B Stewart
- Department of Plant Science, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Carolina Diller
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, 234 56, Sweden
| | - Michele R Dudash
- Department of Natural Resource Management, South Dakota State University, Brookings, SD, 57007, USA
- Department of Biology, University of Maryland, College Park, MD, 20742, USA
| | - Charles B Fenster
- Oak Lake Field Station, South Dakota State University, Brookings, SD, 57007, USA
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8
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Lu NN, Ma Y, Hou M, Zhao ZG. The function of floral traits and phenotypic selection in Aconitum gymnandrum (Ranunculaceae). Plant Biol (Stuttg) 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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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9
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Page ML, Nicholson CC, Brennan RM, Britzman AT, Greer J, Hemberger J, Kahl H, Müller U, Peng Y, Rosenberger NM, Stuligross C, Wang L, Yang LH, Williams NM. A meta-analysis of single visit pollination effectiveness comparing honeybees and other floral visitors. Am J Bot 2021; 108:2196-2207. [PMID: 34622948 DOI: 10.1002/ajb2.1764] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 08/23/2021] [Accepted: 08/23/2021] [Indexed: 06/13/2023]
Abstract
PREMISE Many animals provide ecosystem services in the form of pollination including honeybees, which have become globally dominant floral visitors. A rich literature documents considerable variation in single visit pollination effectiveness, but this literature has yet to be extensively synthesized to address whether honeybees are effective pollinators. METHODS We conducted a hierarchical meta-analysis of 168 studies and extracted 1564 single visit effectiveness (SVE) measures for 240 plant species. We paired SVE data with visitation frequency data for 69 of these studies. We used these data to ask three questions: (1) Do honeybees (Apis mellifera) and other floral visitors differ in their SVE? (2) To what extent do plant and pollinator attributes predict differences in SVE between honeybees and other visitors? (3) Is there a correlation between visitation frequency and SVE? RESULTS Honeybees were significantly less effective than the most effective non-honeybee pollinators but were as effective as the average pollinator. The type of pollinator moderated these effects. Honeybees were less effective compared to the most effective and average bird and bee pollinators but were as effective as other taxa. Visitation frequency and SVE were positively correlated, but this trend was largely driven by data from communities where honeybees were absent. CONCLUSIONS Although high visitation frequencies make honeybees important pollinators, they were less effective than the average bee and rarely the most effective pollinator of the plants they visit. As such, honeybees may be imperfect substitutes for the loss of wild pollinators, and safeguarding pollination will benefit from conservation of non-honeybee taxa.
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Affiliation(s)
- Maureen L Page
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Charlie C Nicholson
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Ross M Brennan
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
- Graduate Group in Ecology, University of California, Davis, Davis, California, 95616, USA
| | - Anna T Britzman
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Jessica Greer
- Graduate Group in Ecology, University of California, Davis, Davis, California, 95616, USA
- Department of Fish, Wildlife, and Conservation Biology, University of California, Davis, Davis, California, 95616, USA
| | - Jeremy Hemberger
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Hanna Kahl
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Uta Müller
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Youhong Peng
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, 610041, China
| | - Nick M Rosenberger
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
- Graduate Group in Ecology, University of California, Davis, Davis, California, 95616, USA
| | - Clara Stuligross
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
- Graduate Group in Ecology, University of California, Davis, Davis, California, 95616, USA
| | - Li Wang
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Louie H Yang
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Neal M Williams
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
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10
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Naghiloo S, Nikzat-Siahkolaee S, Esmaillou Z. Size-matching as an important driver of plant-pollinator interactions. Plant Biol (Stuttg) 2021; 23:583-591. [PMID: 33655638 DOI: 10.1111/plb.13248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 02/14/2021] [Indexed: 06/12/2023]
Abstract
One of the greatest challenges in ecology is to understand and predict the functional outcome of interaction networks. Size-matching between plants and pollinators is one of the key functional traits expected to play a major role in structuring plant-pollinator interactions. However, the community-wide patterns of size-matching remain largely unexplored. We studied the association between the degree of size-matching and foraging efficiency, pollination efficiency and the probability of pairwise interactions in a community of Lamiaceae. Our study revealed that foraging efficiency is maximal when bee proboscis length corresponds to the corolla tube depth of the flower visited. Pollination efficiency was maximal when the bee body height corresponds to the corolla width of the flower visited. While the degree of size-matching did not influence the probability of interaction, it significantly influenced the strength of the interaction in terms of visitation frequency. We suggest a size-matching index as a reliable metric to predict the frequency of interactions as well as the effectiveness of visits in terms of foraging efficiency and pollination efficiency.
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Affiliation(s)
- S Naghiloo
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - S Nikzat-Siahkolaee
- Faculty of Life Sciences & Biotechnology, Shahid Beheshti University, Tehran, Iran
| | - Z Esmaillou
- Department of Horticulture, Urmia University, Tehran, Iran
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11
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Dellinger AS, Pérez-Barrales R, Michelangeli FA, Penneys DS, Fernández-Fernández DM, Schönenberger J. Low bee visitation rates explain pollinator shifts to vertebrates in tropical mountains. New Phytol 2021; 231:864-877. [PMID: 33864287 DOI: 10.1111/nph.17390] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 03/26/2021] [Indexed: 06/12/2023]
Abstract
Evolutionary shifts from bee to vertebrate pollination are common in tropical mountains. Reduction in bee pollination efficiency under adverse montane weather conditions was proposed to drive these shifts. Although pollinator shifts are central to the evolution and diversification of angiosperms, we lack experimental evidence of the ecological processes underlying such shifts. Here, we combine phylogenetic and distributional data for 138 species of the Neotropical plant tribe Merianieae (Melastomataceae) with pollinator observations of 11 and field pollination experiments of six species to test whether the mountain environment may indeed drive such shifts. We demonstrate that shifts from bee to vertebrate pollination coincided with occurrence at high elevations. We show that vertebrates were highly efficient pollinators even under the harsh environmental conditions of tropical mountains, whereas bee pollination efficiency was lowered significantly through reductions in flower visitation rates. Furthermore, we show that pollinator shifts in Merianieae coincided with the final phases of the Andean uplift and were contingent on adaptive floral trait changes to alternative rewards and mechanisms facilitating pollen dispersal. Our results provide evidence that abiotic environmental conditions (i.e. mountain climate) may indeed reduce the efficiency of a plant clade's ancestral pollinator group and correlate with shifts to more efficient new pollinators.
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Affiliation(s)
- Agnes S Dellinger
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, Vienna, 1030, Austria
| | - Rocio Pérez-Barrales
- School of Biological Sciences, University of Portsmouth, King Henry 1st Street, Portsmouth, PO1 2DY, UK
| | - Fabián A Michelangeli
- Institute of Systematic Botany, The New York Botanical Garden, 2900 Southern Blvd, Bronx, NY, 10458-5125, USA
| | - Darin S Penneys
- Biology & Marine Biology, University of North Carolina Wilmington, 601 South College Road, Wilmington, NC, 28403-5915, USA
| | | | - Jürg Schönenberger
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, Vienna, 1030, Austria
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Esposito F, Costa R, Boieiro M. Foraging Behavior and Pollen Transport by Flower Visitors of the Madeira Island Endemic Echium candicans. Insects 2021; 12:insects12060488. [PMID: 34074007 PMCID: PMC8225069 DOI: 10.3390/insects12060488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 05/04/2021] [Accepted: 05/18/2021] [Indexed: 11/20/2022]
Abstract
Simple Summary The successful conservation of many endangered island plants depends on the pollination services provided by animals. In this study, we identify the flower visitors of Echium candicans, a charismatic plant exclusive to the island of Madeira, and also evaluate their performance as pollinators by analyzing their behavior on the flowers and the pollen they transport on their body. We found that many different animals visit this plant’s flowers, from insects to reptiles, but bees were the most frequent visitors. Large bees visited more flowers and transported more pollen of Echium candicans compared to other pollinators, like butterflies and hoverflies. However, by visiting many flowers in the same plant large bees might contribute to inbreeding, whilst the other animals visited fewer flowers in each plant favoring outcrossing. We conclude that the different flower visitors of Echium candicans provide complementary services as pollinators and highlight the importance of having diverse communities of pollinators to ensure successful pollination in many island plants. Abstract The study of flower visitor behavior and pollen transport dynamics within and between plants can be of great importance, especially for threatened or rare plant species. In this work, we aim to assess the flower visitor assemblage of the Madeiran endemic Echium candicans and evaluate the performance of the most common visitors through the analysis of their foraging behavior and pollen loads. The flower visitor assemblage of E. candicans is diverse, including several insect groups and the endemic lizard Teira dugesii, but bees are the most common visitors. In general, large bees (Amegilla quadrifasciata, Apis mellifera, and Bombus spp.) had the highest average visitation rates (>18 flowers/min) and their pollen loads had higher percentages of homospecific pollen (>66%) when compared with butterflies and hoverflies. The honeybee (Apis mellifera) and two bumblebees (Bombus terrestris and B. ruderatus) were the most efficient flower visitors of E. candicans, but their foraging behavior seems to favor geitonogamy. Other visitors, such as butterflies and the small bee Lasioglossum wollastoni, may have a complementary role to the honeybee and bumblebee species, as their high mobility is associated with fewer flower visits on each plant and may promote xenogamy. Two non-native bees (A. mellifera and B. ruderatus) are important flower visitors of E. candicans and may contribute mostly to self-pollination rendering the endemic plant more vulnerable to inbreeding effects.
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Affiliation(s)
- Fabiana Esposito
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal;
- Correspondence:
| | - Ricardo Costa
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal;
| | - Mário Boieiro
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Azorean Biodiversity Group, University of Azores, 9700-042 Angra do Heroísmo, Portugal;
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Chen XH, Tan SL, Liang YL, Huang L, Xiao HW, Luo HL, Xiong DJ, Yang BY, Ren ZX. The pollination of Habenaria rhodocheila (Orchidaceae) in South China: When butterflies take sides. Ecol Evol 2021; 11:2849-2861. [PMID: 33767841 PMCID: PMC7981216 DOI: 10.1002/ece3.7242] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/06/2021] [Accepted: 01/13/2021] [Indexed: 11/10/2022] Open
Abstract
Habenaria is one of the largest terrestrial genera in the family Orchidaceae. Most field studies on Habenaria species with greenish-white and nocturnal scented flowers are pollinated by nocturnal hawkmoths and settling moths. However, H. rhodocheila presents reddish flowers lacking a detectable scent and fails to fit the moth pollination syndrome. We investigated the pollinators, breeding system, and functional traits of H. rhodocheila in South China and found that two diurnal swallowtail butterflies Papilio helenus and Papilio nephelus (Papilionidae) were the effective pollinators. When butterflies foraged for nectar in the spur, the pollinia became attached between the palpi. A triangular projected median rostellar lobe was found at the entrance (sinus) of the spur of H. rhodocheila. This lobe divided the spur opening into two entrances forcing butterflies to enter their proboscides through the left or right side. When the projection of median rostellar lobe was removed, the site of pollinium attachment changed to the eyes of the butterflies, leading to a higher rate of pollinium removal but lower rate of pollinium deposition. Our quartz glass cylinder choice experiment suggested that visual rather than olfactory cues provided the major stimuli for butterflies to locate these flowers. Hand pollination experiments suggested this species was self-compatible but pollinator-dependent. However, the proportion of seeds with large embryos produced in self-pollinated fruits was significantly lower than in cross-pollinated fruits, indicating a significant inbreeding depression. Unlike many other orchid species, fruit set was higher than rates of pollinium removal, indicating a high level of pollination efficiency in a species with friable pollinia. Shifts from moth to butterfly pollination in the genus Habenaria parallel other orchid lineages providing insights into the potential for pollinator-mediated floral trait selection.
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Affiliation(s)
- Xing-Hui Chen
- Jiangxi Key Laboratory of Plant Resources School of Life Sciences Nanchang University Nanchang China
| | - Shao-Lin Tan
- Jiangxi Key Laboratory of Plant Resources School of Life Sciences Nanchang University Nanchang China
| | - Yue-Long Liang
- Jiulianshan National Natural Reserve Administration Bureau Ganzhou China
| | - Lang Huang
- Jiangxi Key Laboratory of Plant Resources School of Life Sciences Nanchang University Nanchang China
| | - Han-Wen Xiao
- Jiangxi Key Laboratory of Plant Resources School of Life Sciences Nanchang University Nanchang China
| | - Huo-Lin Luo
- Jiangxi Key Laboratory of Plant Resources School of Life Sciences Nanchang University Nanchang China
| | - Dong-Jin Xiong
- Jiangxi Key Laboratory of Plant Resources School of Life Sciences Nanchang University Nanchang China
| | - Bo-Yun Yang
- Jiangxi Key Laboratory of Plant Resources School of Life Sciences Nanchang University Nanchang China
| | - Zong-Xin Ren
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of Botany Chinese Academy of Sciences Kunming China
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14
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Wu T, Tang J, Huang SQ. Foraging behavior and pollination efficiency of generalist insects in an understory dioecious shrub Helwingia japonica. Am J Bot 2020; 107:1274-1282. [PMID: 32895943 DOI: 10.1002/ajb2.1524] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 06/11/2020] [Indexed: 06/11/2023]
Abstract
PREMISE It has been hypothesized that pollination success in animal-pollinated dioecious plants relies on opportunistic pollinators with no discrimination against female flowers. However, empirical studies of pollinator foraging behavior and pollination effectiveness in dioecious species are few. METHODS To investigate potential pollinators in Helwingia japonica, a dioecious shrub with small, inconspicuous flowers, we compared floral visitors and visit frequency to female and male plants for three flowering seasons in two field populations in subtropical forests in southwest China. Pollen placement on the insect bodies of four groups (solitary bees and other bees, fungus gnats, and other flies) was compared, and insect foraging behavior was observed. Pollen removal and conspecific and heterospecific pollen deposition per visit were measured to compare pollination effectiveness among the four groups. RESULTS Floral visitors usually did not discriminate between male and female flowers and did not gather pollen into collections. Our measurements of pollen transfer efficiency showed that solitary bees were the most effective pollinators with the highest conspecific pollen deposition. These insects seemed to be opportunistic visitors because pollen grains of H. japonica were distributed evenly over different regions of the visitor's body, and heterospecific pollen accounted for over 50% of total pollen loads on stigmas in the two populations. CONCLUSIONS Our investigations indicated that potential pollinators were generalists and did not discriminate against female flowers, as predicted for dioecious species pollinated by insects. A perspective of pollen removal by floral visitors offers insights into the evolution of plant sexual systems.
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Affiliation(s)
- Ting Wu
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Ju Tang
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Shuang-Quan Huang
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
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15
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Abstract
Bird pollination systems are dominated by specialist nectarivores, such as hummingbirds in the Americas and sunbirds in Africa. Opportunistic (generalist) avian nectarivores such as orioles, weavers and bulbuls have also been implicated as plant pollinators, but their effectiveness as agents of pollen transfer is poorly known. Here, we compare the single-visit effectiveness of specialist and opportunistic avian nectarivores as pollinators of Aloe ferox, a plant that relies almost exclusively on birds for seed production. We found that the number of pollen grains on stigmas of flowers receiving single visits by opportunistic avian nectarivores was approximately threefold greater than on those receiving single visits by specialist sunbirds and about twofold greater than on those that received single visits by honeybees. The number of pollen grains on stigmas of flowers visited by sunbirds was similar to that on stigmas of unvisited flowers. These results show that opportunistic birds are highly effective pollinators of A. ferox, supporting the idea that some plants are specialized for pollination by opportunistic birds.
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Affiliation(s)
- Carolina Diller
- Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermartizburg 3209, South Africa
| | - Miguel Castañeda-Zárate
- Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermartizburg 3209, South Africa
| | - Steven D Johnson
- Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermartizburg 3209, South Africa
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16
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Vlasáková B, Pinc J, Jůna F, Kotyková Varadínová Z. Pollination efficiency of cockroaches and other floral visitors of Clusia blattophila. Plant Biol (Stuttg) 2019; 21:753-761. [PMID: 30620429 DOI: 10.1111/plb.12956] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 01/04/2019] [Indexed: 06/09/2023]
Abstract
Cockroaches have rarely been documented as pollinators. In this paper we examine whether this is because they might be inefficient at pollination compared to other pollinators. Clusia blattophila, a dioecious shrub growing on isolated rocky outcrops in French Guiana, is pollinated by Amazonina platystylata cockroaches and provides a valuable system for the study of cockroach pollination efficiency. We examined the species composition of the visitor guild and visitation rates by means of camcorder recordings and visitor sampling. Then, we investigated the capacity for pollen transfer of principal visitors and found correlations between visitation rates and pollen loads on stigmas. In an exclusion experiment we determined the contributions of individual species to pollination success. Amazonina platystylata, crickets and two species of Diptera transferred pollen, but the number of transferred pollen grains was only related to visitation rates in the case of cockroaches. Crickets visited and rarely carried pollen. Dipterans were as frequent as cockroaches, carried similar pollen loads, but transferred much less pollen. An estimated 41% and 17% of ovules were pollinated by cockroaches and dipterans, respectively. The remaining ovules were not pollinated. There was no spatial variation in pollinator guild composition, but cockroaches visited flowers less frequently at the smaller study site. We demonstrate that cockroaches pollinate a large proportion of ovules. Their pollination service is not confined to one study site and, unlike that provided by dipterans, is not limited to certain years. We suggest that cockroach pollination has been overlooked and that cockroach-pollinated plants, which share certain floral features, possess adaptations to pollination by cockroaches.
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Affiliation(s)
- B Vlasáková
- Department of Population Ecology, Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice, Czech Republic
| | - J Pinc
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic
| | - F Jůna
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Z Kotyková Varadínová
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
- Department of Zoology, National Museum, Prague, Czech Republic
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17
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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18
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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: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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19
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Rodríguez-García E, Mezquida ET, Olano JM. You'd better walk alone: Changes in forest composition affect pollination efficiency and pre-dispersal cone damage in Iberian Juniperus thurifera forests. Plant Biol (Stuttg) 2017; 19:934-941. [PMID: 28834121 DOI: 10.1111/plb.12613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/13/2017] [Indexed: 06/07/2023]
Abstract
Changes in land-use patterns are a major driver of global environmental change. Cessation of traditional land-use practices has led to forest expansion and shifts in forest composition. Consequently, former monospecific forests maintained by traditional management are progressing towards mixed forests. However, knowledge is scarce on how the presence of other tree species will affect reproduction of formerly dominant species. We explored this question in the wind-pollinated tree Juniperus thurifera. We hypothesised that the presence of heterospecific trees would have a negative effect on cone production and on the proportion of cones attacked by specialised predators. We assessed the relative importance of forest composition on cone production, seed development and pre-dispersal cone damage on nine paired pure and mixed J. thurifera forests in three regions across the Iberian Peninsula. The effects of forest composition on crop size, cone and seed characteristics, as well as damage by pre-dispersal arthropods were tested using mixed models. Cone production was lower and seed abortion higher in mixed forests, suggesting higher pollination failure. In contrast, cone damage by arthropods was higher in pure forests, supporting the hypothesis that presence of non-host plants reduces damage rates. However, the response of each arthropod to forest composition was species-specific and the relative rates of cone damage varied depending on individual tree crops. Larger crop sizes in pure forests compensated for the higher cone damage rates, leading to a higher net production of sound seeds compared to mixed forests. This study indicates that ongoing changes in forest composition after land abandonment may impact tree reproduction.
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Affiliation(s)
- E Rodríguez-García
- Laboratorio de Botánica, Department of Agroforestry Sciences - iuFOR, Universidad de Valladolid, Soria, Spain
| | - E T Mezquida
- Department of Ecology, Faculty of Sciences, Autonomous University of Madrid, Madrid, Spain
| | - J M Olano
- Laboratorio de Botánica, Department of Agroforestry Sciences - iuFOR, Universidad de Valladolid, Soria, Spain
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20
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Fernández de Castro AG, Moreno-Saiz JC, Fuertes-Aguilar J. Ornithophily for the nonspecialist: Differential pollination efficiency of the Macaronesian island paleoendemic Navaea phoenicea (Malvaceae) by generalist passerines. Am J Bot 2017; 104:1556-1568. [PMID: 29885219 DOI: 10.3732/ajb.1700204] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 08/31/2017] [Indexed: 06/08/2023]
Abstract
PREMISE OF THE STUDY A bird pollination syndrome exists in the Canary Islands archipelago across independent plant lineages despite the absence of specialist birds. The pollination efficiency of current floral visitors remains unknown for many plant species despite this being a fundamental factor in testing hypotheses about the origin of the syndrome. Here, we studied the components of pollination efficiency in the paleoendemic Navaea phoenicea, a species exhibiting conspicuous anatomical modifications associated with bird pollination. METHODS We measured the components of the pollination efficiency (PE) of species foraging on flowers. The measured quantitative components were visitation frequency patterns to plants and individual flowers. The qualitative components were the contributions to the fitness of male and female functions (pollen removal and deposition and fruit set). KEY RESULTS Pollination by warbler species was highly efficient, but visit frequency was low; conversely, Canarian chiffchaffs had high visit frequency and low efficiency. Overall PE was almost 0 for blue tits due to disruptive behavior. We also found insects acting as nectar robbers. CONCLUSIONS Pollination efficiency of three of the four bird species visiting flowers of Navaea phoenicea may be high enough to maintain selective pressure on floral traits of a relict pollination syndrome. The behavior of these birds plays a crucial role in their pollination efficiency. Perching, by generalist passerines when visiting N. phoenicea flowers, is the most efficient habit. The frequency and PE of insect visits calls into question their role as legitimate visitors.
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Affiliation(s)
| | - Juan Carlos Moreno-Saiz
- Departamento de Biología (Botánica), Calle Darwin 2, Campus de Cantoblanco, Universidad Autónoma de Madrid 28049 Madrid, Spain
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21
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Wang H, Cao GX, Wang LL, Yang YP, Zhang ZQ, Duan YW. Evaluation of pollinator effectiveness based on pollen deposition and seed production in a gynodieocious alpine plant, Cyananthus delavayi. Ecol Evol 2017; 7:8156-8160. [PMID: 29075439 PMCID: PMC5648671 DOI: 10.1002/ece3.3391] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 07/26/2017] [Accepted: 08/03/2017] [Indexed: 11/24/2022] Open
Abstract
Examining variations in pollinator effectiveness can enhance our understanding of how pollinators and plants interact. Pollen deposition and seed production after a single visit by a pollinator are often used to estimate pollinator effectiveness. However, seed production is not always directly related to pollen deposition because not all pollen grains that are deposited on a stigma are compatible or conspecific. In the field, we tested pollinator effectiveness based on pollen deposition and the resulting seed production after single visits by different pollinator groups in a gynodieocious alpine plant Cyananthus delavayi (Campanulaceae). Our results showed that mean pollen deposition was generally inconsistent with mean seed production when comparisons were performed among different pollinator groups and sexes. In general, the correlations were not significant between pollen deposition and seed production in both perfect and female flowers after single visits by halictid bees, bumble bees, and hoverflies. We suggest seed set of virgin flowers after single visits is a more reliable indicator of pollinator effectiveness than pollen deposition and would be a better indicator of pollinator effectiveness for future studies.
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Affiliation(s)
- Hao Wang
- Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of Botany Chinese Academy of Sciences Kunming China.,Department of Forestry Sichuan Agricultural University Chengdu China
| | - Guo-Xing Cao
- Department of Forestry Sichuan Agricultural University Chengdu China
| | - Lin-Lin Wang
- Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of Botany Chinese Academy of Sciences Kunming China
| | - Yong-Ping Yang
- Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of Botany Chinese Academy of Sciences Kunming China
| | - Zhi-Qiang Zhang
- Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of Botany Chinese Academy of Sciences Kunming China.,Laboratory of Ecology and Evolutionary Biology State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan Yunnan University Kunming China
| | - Yuan-Wen Duan
- Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of Botany Chinese Academy of Sciences Kunming China
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22
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Jin XF, Ye ZM, Amboka GM, Wang QF, Yang CF. Stigma Sensitivity and the Duration of Temporary Closure Are Affected by Pollinator Identity in Mazus miquelii (Phrymaceae), a Species with Bilobed Stigma. Front Plant Sci 2017; 8:783. [PMID: 28539934 PMCID: PMC5423900 DOI: 10.3389/fpls.2017.00783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 04/25/2017] [Indexed: 06/07/2023]
Abstract
A sensitive bilobed stigma is thought to assure reproduction, avoid selfing and promote outcrossing. In addition, it may also play a role in pollinator selection since only pollinators with the appropriate body size can trigger this mechanism. However, no experimental study has investigated how the sensitive stigma responds to different pollinators and its potential effects on pollination. Mazus miquelii (Phrymaceae), a plant with a bilobed stigma was studied to investigate the relationship between stigma behaviors and its multiple insect pollinators. The reaction time of stigma closure after touched, duration of temporary closure, and factors determining permanent closure of the stigma were studied when flowers were exposed to different visitors and conducted with hand pollination. Manual stimulation was also used to detect the potential differences in stigmas when touched with different degrees of external forces. Results indicated that, compared to pollinators with a small body size, larger pollinators transferred more pollen grains to the stigma, causing a rapid stigma response and resulting in a higher percentage of permanent closures. Duration of temporary closure was negatively correlated with the speed of stigma closure; a stigma that closed more rapidly reopened more slowly. Manual stimulation showed that reaction time of stigma closure was likely a response to external mechanical forces. Hand pollination treatments revealed that the permanent closure of a stigma was determined by the size of stigmatic pollen load. For large pollinators, the speedy reaction of the stigma might help to reduce pollen loss, enhance pollen germination and avoid obstructing pollen export. Stigmas showed low sensitivity when touched by inferior pollinators, which may have increased the possibility of pollen deposition by subsequent visits. Therefore, the stigma behavior in M. miquelii is likely a mechanism of pollinator selection to maximize pollination success.
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Affiliation(s)
- Xiao-Fang Jin
- Institute of Ecology and Environmental Science, Nanchang Institute of TechnologyNanchang, China
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
| | - Zhong-Ming Ye
- Jiangxi Provincial Key Laboratory of Soil Erosion and Prevention, Jiangxi Institute of Soil and Water ConservationNanchang, China
| | - Grace M. Amboka
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
- College of Life Sciences, University of Chinese Academy of SciencesBeijing, China
| | - Qing-Feng Wang
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
| | - Chun-Feng Yang
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
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23
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Abstract
UNLABELLED • PREMISE OF THE STUDY Although rewarding orchids are believed to have a high pollination efficiency, pollination success is often low, suggesting that rewarding orchids may be prone to pollen limitation. Assuming that selfing contributes significantly to fruit and seed set (i.e., reproductive assurance) and that the quality of selfed seeds is high (i.e., low inbreeding depression), it can be hypothesized that under these circumstances populations evolve to facultative or even complete self-pollination.• METHODS In this study, we performed emasculation and pollen supplementation experiments in the field to assess the extent of outcross pollen limitation and the contribution of autonomous self-pollination to fruit and seed set in the rewarding orchid Epipactis palustris. Hand-pollinations using cross and self-pollen were performed in the greenhouse to investigate the impact of selfing on seed set and seed quality and to assess the magnitude of inbreeding depression.• KEY RESULTS Fruit set under natural conditions was high: ca. 70% of all flowers set fruit. Percentage fruit set of emasculated plants was 56%, implying that fruit set in about 14% of all flowers was the result of autonomous self-pollination. Pollen supplementation significantly increased fruit and seed set, indicating strong outcross pollen limitation. Hand-pollination with cross pollen resulted in significantly higher seed set and seed quality compared with manual self-pollination, indicating high levels of early inbreeding depression (δ = 0.46 ± 0.08).• CONCLUSIONS Overall, these results indicate that, despite the high pollination efficiency, populations of this rewarding orchid species were strongly pollen limited. Costs of early inbreeding depression, on the other hand, were high, which may prevent rapid evolution of complete selfing.
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Affiliation(s)
- Hans Jacquemyn
- KU Leuven, Biology Department, Plant Conservation and Population Biology, Kasteelpark Arenberg 31, B-3001 Heverlee, Belgium
| | - Rein Brys
- KU Leuven, Biology Department, Plant Conservation and Population Biology, Kasteelpark Arenberg 31, B-3001 Heverlee, Belgium
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Nagano Y, Abe K, Kitazawa T, Hattori M, Hirao AS, Itino T. Changes in pollinator fauna affect altitudinal variation of floral size in a bumblebee-pollinated herb. Ecol Evol 2014; 4:3395-407. [PMID: 25535556 PMCID: PMC4228614 DOI: 10.1002/ece3.1191] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 07/17/2014] [Accepted: 07/21/2014] [Indexed: 11/07/2022] Open
Abstract
Geographic trait variations are often caused by locally different selection regimes. As a steep environmental cline along altitude strongly influences adaptive traits, mountain ecosystems are ideal for exploring adaptive differentiation over short distances. We investigated altitudinal floral size variation of Campanula punctata var. hondoensis in 12 populations in three mountain regions of central Japan to test whether the altitudinal floral size variation was correlated with the size of the local bumblebee pollinator and to assess whether floral size was selected for by pollinator size. We found apparent geographic variations in pollinator assemblages along altitude, which consequently produced a geographic change in pollinator size. Similarly, we found altitudinal changes in floral size, which proved to be correlated with the local pollinator size, but not with altitude itself. Furthermore, pollen removal from flower styles onto bees (plant's male fitness) was strongly influenced by the size match between flower style length and pollinator mouthpart length. These results strongly suggest that C. punctata floral size is under pollinator-mediated selection and that a geographic mosaic of locally adapted C. punctata exists at fine spatial scale.
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Affiliation(s)
- Yusuke Nagano
- Department of Biology, Faculty of Science, Shinshu University3-1-1 Asahi, Matsumoto, Nagano, 390-8621, Japan
| | - Kota Abe
- Department of Biology, Faculty of Science, Shinshu University3-1-1 Asahi, Matsumoto, Nagano, 390-8621, Japan
| | - Tomoaki Kitazawa
- Department of Biology, Faculty of Science, Shinshu University3-1-1 Asahi, Matsumoto, Nagano, 390-8621, Japan
| | - Mitsuru Hattori
- Department of Biology, Faculty of Science, Shinshu University3-1-1 Asahi, Matsumoto, Nagano, 390-8621, Japan
| | - Akira S Hirao
- Sugadaira Montane Research Center, University of TsukubaUeda, Nagano, 386–2201, Japan
| | - Takao Itino
- Department of Biology, Faculty of Science, Shinshu University3-1-1 Asahi, Matsumoto, Nagano, 390-8621, Japan
- Institute of Mountain Science, Shinshu University3-1-1 Asahi, Matsumoto, Nagano, 390-8621, Japan
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Li XX, Wang H, Gituru RW, Guo YH, Yang CF. Pollen packaging and dispensing: adaption of patterns of anther dehiscence and flowering traits to pollination in three Epimedium species. Plant Biol (Stuttg) 2014; 16:227-233. [PMID: 23614841 DOI: 10.1111/plb.12040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 03/20/2013] [Indexed: 06/02/2023]
Abstract
Pollen presentation theory (PPT) predicts that plant species typically pollinated by frequent and wasteful pollinators ought to be much more parsimonious and only gradually release pollen compared to plant species pollinated by infrequent pollinators that are efficient at delivering the pollen they remove. To test PPT, we compare the pollen presentation schedules and pollination systems in three related Epimedium species, having different pollinators. Results showed that differences in anther dehiscence and flowering traits resulted in different pollen packaging schedules. For E. sutchuenense and E. franchetii, a special 'roll-up' movement of the anther wall during anther dehiscence increased pollen removal compared to the dehiscence pattern in E. mikinorii, which lacked the 'roll-up' movement. Investigations revealed that honeybees had a higher pollen removal rate and lower stigmatic pollen load compared to bumblebees. In accordance with PPT, E. sutchuenense presents pollen sequentially and slowly for the frequent and wasteful honeybees. In comparison to E. sutchuenense, E. franchetii had a faster presentation rate and was adapted to the efficient and infrequent bumblebees. However, E. mikinorii was pollinated by both bumblebees and honeybees at high frequency and had the fastest pollen presentation. This pattern could reduce pollen wastage by honeybees and might be an adaptation to its short flower longevity (less than 1 day), to increase the chances of pollen deposition on stigmas. The study indicates that pollen presentation schedules can be a consequence of interactions among anther dehiscence, flowering traits and pollination environments for a given species.
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Affiliation(s)
- X-X Li
- College of Life Sciences, Wuhan University, Wuhan, China
| | - H Wang
- College of Life Sciences, Wuhan University, Wuhan, China
| | - R W Gituru
- Sino-African Biodiversity Resource Conservation centre, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Y-H Guo
- College of Life Sciences, Wuhan University, Wuhan, China
| | - C-F Yang
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan, China
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Hargreaves AL, Harder LD, Johnson SD. Floral traits mediate the vulnerability of aloes to pollen theft and inefficient pollination by bees. Ann Bot 2012; 109:761-772. [PMID: 22278414 PMCID: PMC3286288 DOI: 10.1093/aob/mcr324] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 12/09/2011] [Indexed: 05/30/2023]
Abstract
BACKGROUND AND AIMS Pollen-collecting bees are among the most important pollinators globally, but are also the most common pollen thieves and can significantly reduce plant reproduction. The pollination efficiency of pollen collectors depends on the frequency of their visits to female(-phase) flowers, contact with stigmas and deposition of pollen of sufficient quantity and quality to fertilize ovules. Here we investigate the relative importance of these components, and the hypothesis that floral and inflorescence characteristics mediate the pollination role of pollen collection by bees. METHODS For ten Aloe species that differ extensively in floral and inflorescence traits, we experimentally excluded potential bird pollinators to quantify the contributions of insect visitors to pollen removal, pollen deposition and seed production. We measured corolla width and depth to determine nectar accessibility, and the phenology of anther dehiscence and stigma receptivity to quantify herkogamy and dichogamy. Further, we compiled all published bird-exclusion studies of aloes, and compared insect pollination success with floral morphology. KEY RESULTS Species varied from exclusively insect pollinated, to exclusively bird pollinated but subject to extensive pollen theft by insects. Nectar inaccessibility and strong dichogamy inhibited pollination by pollen-collecting bees by discouraging visits to female-phase (i.e. pollenless) flowers. For species with large inflorescences of pollen-rich flowers, pollen collectors successfully deposited pollen, but of such low quality (probably self-pollen) that they made almost no contribution to seed set. Indeed, considering all published bird-exclusion studies (17 species in total), insect pollination efficiency varied significantly with floral shape. CONCLUSIONS Species-specific floral and inflorescence characteristics, especially nectar accessibility and dichogamy, control the efficiency of pollen-collecting bees as pollinators of aloes.
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Affiliation(s)
- Anna L Hargreaves
- Department of Biological Sciences, University of Calgary, Alberta, Canada.
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Kuriakose G, Sinu PA, Shivanna KR. Domestication of cardamom (Elettaria cardamomum) in Western Ghats, India: divergence in productive traits and a shift in major pollinators. Ann Bot 2009; 103:727-733. [PMID: 19126635 PMCID: PMC2707870 DOI: 10.1093/aob/mcn262] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 10/29/2008] [Accepted: 11/06/2008] [Indexed: 05/27/2023]
Abstract
BACKGROUND AND AIMS Elettaria cardamomum, a highly priced spice, is native to the Western Ghats of South India. Wild populations still occur in isolated patches in their natural habitats; however, much of today's commercial product comes from cultivated sources. There is no information on domestication-related traits of this species; the main objective of this study was to compare wild and cultivated populations of cardamom in terms of vegetative and reproductive features in order to identify domestication syndromes and to examine whether the two populations have developed reproductive barriers. METHODS Two wild populations and five cultivated plantations were used for the present study. Vegetative and floral traits, flowering phenology, pollination biology and breeding systems of wild and cultivated populations were compared. Effective pollinators amongst floral visitors were identified by confirming pollen transfer as well as by fruit set following their visit to virgin flowers. Manual pollinations were carried out in order to study the breeding systems of the two populations and reproductive barriers, if any, between them. KEY RESULTS Several productive traits including the number of branches, number of inflorescences, and total number of flowers per clump, number of flowers that open each day, the duration of flowering, the length of the flower and the amount of nectar per flower are significantly greater in cultivated cardamom. The principal pollinators in wild cardamom are solitary bees, Megachile sp. and two species of Amegilla, whereas those in cultivated cardamom are the social bees Apis dorsata, A. cerana and Trigona iridipennis. Both the wild and cultivated populations are self-compatible and there are no reproductive barriers between the two populations. CONCLUSIONS Domestication in cardamom has brought about significant changes in vegetative and reproductive traits and a shift in effective pollinators from native solitary bees to social bees. The shift in pollinators seems to be due to the availability of a large number of flowers for prolonged periods in cultivated cardamom that can attract and sustain social bees, rather than due to co-evolution of the flower and the pollinator.
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Michalski SG, Durka W. Synchronous pulsed flowering: analysis of the flowering phenology in Juncus (Juncaceae). Ann Bot 2007; 100:1271-85. [PMID: 17881343 PMCID: PMC2759248 DOI: 10.1093/aob/mcm206] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 06/29/2007] [Accepted: 07/16/2007] [Indexed: 05/17/2023]
Abstract
BACKGROUND AND AIMS The timing of flowering within and among individuals is of fundamental biological importance because of its influence on total seed production and, ultimately, fitness. Traditional descriptive parameters of flowering phenology focus on onset and duration of flowering and on synchrony among individuals. These parameters do not adequately account for variability in flowering across the flowering duration at individual and population level. This study aims to analyse the flowering phenology of wind-pollinated Juncus species that has been described as temporally highly variable ('pulsed flowering'). Additionally, an attempt is made to identify proximate environmental factors that may cue the flowering, and ultimate causes for the flowering patterns are discussed. METHODS Flowering phenology was examined in populations of nine Juncus species by estimating flowering synchrony and by using the coefficient of variation (CV) to describe the temporal variation in flowering on individual and population levels. Phenologies were compared with null models to test which patterns deviate from random flowering. All parameters assessed were compared with each other and the performance of the parameters in response to randomization and varying synchrony was evaluated using a model population. Flowering patterns were correlated with temperature and humidity. KEY RESULTS Most flowering patterns of Juncus were best described as synchronous pulsed flowering, characterized as population-wide concerted flowering events separated by days with no or few open flowers. Flowering synchrony and variability differed from a random pattern in most cases. CV values in combination with a measure of synchrony differentiated among flowering patterns found. Synchrony varied among species and was independent from variability in flowering. Neither temperature nor humidity could be determined as potential cues for the flowering pulses. CONCLUSIONS The results indicate that selection may act independently on synchrony and variability. We propose that synchronous pulsed flowering in Juncus is an evolved strategy that provides selective benefits by increasing outcrossing and by spreading the risk of reproductive failure.
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Affiliation(s)
- Stefan G Michalski
- Helmholtz Centre for Environmental Research - UFZ, Department of Community Ecology (BZF), Theodor-Lieser-Strasse 4, D-06120 Halle, Germany.
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