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Nathan M, Gruner DS. Sustained mangrove reproduction despite major turnover in pollinator community composition at expanding range edge. Ann Bot 2023; 132:107-120. [PMID: 37389585 PMCID: PMC10550273 DOI: 10.1093/aob/mcad085] [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] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 06/29/2023] [Indexed: 07/01/2023]
Abstract
BACKGROUND AND AIMS How well plants reproduce near their geographic range edge can determine whether distributions will shift in response to changing climate. Reproduction at the range edge can be limiting if pollinator scarcity leads to pollen limitation, or if abiotic stressors affect allocation to reproduction. For many animal-pollinated plants with expanding ranges, the mechanisms by which they have overcome these barriers are poorly understood. METHODS In this study, we examined plant-pollinator interactions hypothesized to impact reproduction of the black mangrove, Avicennia germinans, which is expanding northward in coastal Florida, USA. We monitored insects visiting A. germinans populations varying in proximity to the geographic range edge, measured the pollen loads of the most common insect taxa and pollen receipt by A. germinans stigmas, and quantified flower and propagule production. KEY RESULTS We found that despite an 84 % decline in median floral visits by insects at northernmost versus southernmost sites, range-edge pollen receipt remained high. Notably, local floral visitor assemblages exhibited substantial turnover along the study's latitudinal gradient, with large-bodied bees and hover flies increasingly common at northern sites. We also observed elevated flower production in northern populations and higher per capita reproductive output at the range edge. Furthermore, mean propagule mass in northern populations was 18 % larger than that from the southernmost populations. CONCLUSIONS These findings reveal no erosion of fecundity in A. germinans populations at range limits, allowing rapid expansion of mangrove cover in the region. These results also illustrate that substantial turnover in the assemblage of flower-visiting insects can occur at an expanding range edge without altering pollen receipt.
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Affiliation(s)
- Mayda Nathan
- Department of Entomology, University of Maryland, College Park, MD 20742, USA
| | - Daniel S Gruner
- Department of Entomology, University of Maryland, College Park, MD 20742, USA
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2
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Rauf A, Saeed S, Ali M, Nadeem Tahir MH. Comparative Efficiency of Native Insect Pollinators in Reproductive Performance of Medicago sativa L. in Pakistan. Insects 2021; 12:1029. [PMID: 34821829 DOI: 10.3390/insects12111029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 11/16/2022]
Abstract
Lucerne (Medicago sativa L.) is a cross-pollinated crop and requires entomophilous pollination for tripping of flowers and subsequent pod and seed set. To discover the best pollinators for lucerne seed production, a two-year field trial was carried out at the research farm of MNS University of Agriculture, Multan, Pakistan. Abundance and diversity of insect pollinators along with the foraging behavior were recorded in terms of tripping efficiency, stay time, visitation rate and pollen harvest. The single-visit efficiency of abundant insect pollinators was also evaluated in terms of number of seeds and seed weight per raceme along with germination percentage. Ten most abundant floral visitors (five solitary bee species, three honeybee species and two syrphid fly species) were tested for their pollination efficiency. Honeybees were most abundant in both the years followed by the solitary bees and syrphid flies. Single-visit efficacy in terms of number of pods per raceme, number of seeds per raceme, 1000 seed weight and germination percentage revealed Megachile cephalotes as the most efficient insect pollinator followed by Megachile hera and Amegilla sp. Future studies should investigate the biology and ecology of these bee species with special emphasis on their nesting behavior and seasonality.
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Jing S, Kryger P, Markussen B, Boelt B. Pollination and Plant Reproductive Success of Two Ploidy Levels in Red Clover ( Trifolium pratense L.). Front Plant Sci 2021; 12:720069. [PMID: 34421974 PMCID: PMC8374103 DOI: 10.3389/fpls.2021.720069] [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] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 07/06/2021] [Indexed: 06/13/2023]
Abstract
Plant reproduction in red clover requires cross-fertilization via insect pollination. However, the influences of visitation rate and timing on maximizing ovule utilization are yet to be determined. We aimed to study the influences of visitation rate, flowering stage, and self-incompatibility on reproductive success. We applied hand and honey bee pollination in the study of eight red clover cultivars with two ploidy levels released between 1964 and 2001. In hand pollination, increasing the visitation rates (from 10 to 80 pollinated florets per flower head) increased the seed number per flower head but reduced the seed number per pollinated floret. Different flowering stages (early, middle, and full flowering) did not influence the seed number per pollinated floret significantly. There was a marked difference in reproductive success depending on the ploidy level, with 0.52 seeds per pollinated floret in diploid and 0.16 in tetraploid cultivars. During the cultivar release history, seed number per pollinated floret seemed to decrease in diploid cultivars, whereas it increased in tetraploids. In honey bee pollination, diploid cultivars had more two-seeded florets than tetraploids. Different visitation rates and the stochastic nature of pollen transfer resulted in difficulties when the plant reproductive success between hand and bee pollination was compared. A maximum of 0.27 seeds per pollinated floret were produced in hand pollination compared to the 0.34 in honey bee pollination. In spite of this, hand pollination provided a valuable method for studying the pollination biology and reproduction of red clover. Future studies may employ hand pollination to unravel further aspects of the low reproductive success with the future perspective of improving seed number per pollinated floret in tetraploid red clover.
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Affiliation(s)
- Shuxuan Jing
- Department of Agroecology, Aarhus University, Slagelse, Denmark
| | - Per Kryger
- Department of Agroecology, Aarhus University, Slagelse, Denmark
| | - Bo Markussen
- Department of Mathematical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Birte Boelt
- Department of Agroecology, Aarhus University, Slagelse, Denmark
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Buide ML, Del Valle JC, Prado-Comesaña A, Narbona E. The effects of pollination, herbivory and autonomous selfing on the maintenance of flower colour variation in Silenelittorea. Plant Biol (Stuttg) 2021; 23:275-284. [PMID: 33179369 DOI: 10.1111/plb.13209] [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: 06/26/2020] [Accepted: 10/30/2020] [Indexed: 05/23/2023]
Abstract
Intraspecific flower colour variation has been generally proposed to evolve as a result of selection driven by biotic or abiotic agents. In a polymorphic population of Silene littorea with pink- and white-flowered plants, we studied pollinators, analysed flower colour perception and tested for differences in pollinator visitation. We also experimentally analysed pollinator limitation in fruit and seed set, and the degree of autonomous selfing. The incidence of florivory and leaf herbivory was compared over 3-4 years. Silene littorea is mainly pollinated by bees and butterflies. Pollinators preferred pink flowers, which did not show pollinator limitation. On the contrary, white flowers showed pollinator limitation in fruit set. White-flowered plants had less floral display and higher levels of florivory than pink plants. Flower colour morphs of S. littorea can reproduce in the absence of pollinators by autonomous selfing, setting 20% and 12% of fruit and seeds in the pink morph and 27% and 20% in the white morph, respectively. Fruit set of white flowers produced by autonomous selfing did not differ from open-pollinated flowers. In conclusion, S. littorea is pollinated by insects of different orders that more frequently visit pink flowers, which is reflected in pollinator limitation of fruit set in white flowers. Moreover, this species has a mixed mating system in which both colour morphs can reproduce in the absence of pollinators by autonomous selfing, although white flowers mainly produce fruits by autogamy. We suggest that reproductive assurance by autonomous selfing helps to maintain flower colour polymorphism in this population.
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Affiliation(s)
- M L Buide
- Department of Molecular Biology and Biochemical Engineering, Pablo de Olavide University, Seville, Spain
| | - J C Del Valle
- Department of Molecular Biology and Biochemical Engineering, Pablo de Olavide University, Seville, Spain
| | - A Prado-Comesaña
- Department of Analytical and Food Chemistry, University of Vigo, Vigo, Spain
| | - E Narbona
- Department of Molecular Biology and Biochemical Engineering, Pablo de Olavide University, Seville, Spain
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Medel R, González-Browne C, Salazar D, Ferrer P, Ehrenfeld M. The most effective pollinator principle applies to new invasive pollinators. Biol Lett 2019; 14:rsbl.2018.0132. [PMID: 29899130 DOI: 10.1098/rsbl.2018.0132] [Citation(s) in RCA: 10] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 05/21/2018] [Indexed: 01/01/2023] Open
Abstract
G. L. Stebbins' most effective pollinator principle states that when pollinators are not limiting, plants are expected to specialize and adapt to the most abundant and effective pollinator species available. In this study, we quantify the effectiveness of bees, hummingbirds and hawkmoths in a Chilean population of Erythranthe lutea (Phrymaceae), and examine whether flower traits are subject to pollinator-mediated selection by the most effective pollinator species during two consecutive years. Unlike most species in the pollinator community, the visitation rate of the recently arrived Bombus terrestris did not change substantially between years, which together with its high and stable pollen delivery to flower stigmas made this species the most important in the pollinator assemblage, followed by the solitary bee Centris nigerrima Flower traits were under significant selection in the direction expected for short-tongue bees, suggesting that E. lutea is in the initial steps of adaptation to the highly effective exotic bumblebee. Our results illustrate the applicability of Stebbins' principle for new invasive pollinators, and stress their importance in driving flower adaptation of native plant species, a critical issue in the face of biotic exchange and homogenization.
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Affiliation(s)
- Rodrigo Medel
- Departamento de Ecología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Santiago, Chile
| | - Catalina González-Browne
- Departamento de Ecología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Santiago, Chile
| | - Daniela Salazar
- Departamento de Ecología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Santiago, Chile
| | - Pedro Ferrer
- Departamento de Ecología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Santiago, Chile
| | - Mildred Ehrenfeld
- Departamento de Ecología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Santiago, Chile
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Fijen TPM, Scheper JA, Boom TM, Janssen N, Raemakers I, Kleijn D. Insect pollination is at least as important for marketable crop yield as plant quality in a seed crop. Ecol Lett 2018; 21:1704-1713. [PMID: 30189466 DOI: 10.1111/ele.13150] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [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: 03/20/2018] [Revised: 04/23/2018] [Accepted: 08/06/2018] [Indexed: 11/30/2022]
Abstract
The sustainability of agriculture can be improved by integrating management of ecosystem services, such as insect pollination, into farming practices. However, large-scale adoption of ecosystem services-based practices in agriculture is lacking, possibly because growers undervalue the benefits of ecosystem services compared to those of conventional management practices. Here we show that, under representative real-world conditions, pollination and plant quality made similar contributions to marketable seed yield of hybrid leek (Allium porrum). Relative to the median, a 25% improvement of plant quality and pollination increased crop value by an estimated $18 007 and $17 174 ha-1 respectively. Across five crop lines, bumblebees delivered most pollination services, while other wild pollinator groups made less frequent but nevertheless substantial contributions. Honeybees actively managed for pollination services did not make significant contributions. Our results show that wild pollinators are an undervalued agricultural input and managing for enhancing pollinators makes sense economically in high-revenue insect-pollinated cropping systems.
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Affiliation(s)
- Thijs P M Fijen
- Wageningen University, Plant Ecology and Nature Conservation Group, Droevendaalsesteeg 3a, Wageningen, 6708 PB, The Netherlands
| | - Jeroen A Scheper
- Wageningen University, Plant Ecology and Nature Conservation Group, Droevendaalsesteeg 3a, Wageningen, 6708 PB, The Netherlands.,Animal Ecology Team, Wageningen Environmental Research, Droevendaalsesteeg 3a, Wageningen, 6708 PB, The Netherlands
| | - Timo M Boom
- Wageningen University, Plant Ecology and Nature Conservation Group, Droevendaalsesteeg 3a, Wageningen, 6708 PB, The Netherlands
| | - Nicole Janssen
- Wageningen University, Plant Ecology and Nature Conservation Group, Droevendaalsesteeg 3a, Wageningen, 6708 PB, The Netherlands
| | - Ivo Raemakers
- Van Caldenborghstraat 26, Gronsveld, 6247CG, The Netherlands
| | - David Kleijn
- Wageningen University, Plant Ecology and Nature Conservation Group, Droevendaalsesteeg 3a, Wageningen, 6708 PB, The Netherlands
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Sapir Y, Karoly K, Koelling VA, Sahli HF, Knapczyk FN, Conner JK. Effect of expanded variation in anther position on pollinator visitation to wild radish, Raphanus raphanistrum. Ann Bot 2017; 120:665-672. [PMID: 28531293 PMCID: PMC5714124 DOI: 10.1093/aob/mcx041] [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: 11/26/2016] [Revised: 02/04/2017] [Accepted: 03/17/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND AND AIMS Plant-pollinator interactions shape the evolution of flowers. Floral attraction and reward traits have often been shown to affect pollinator behaviour, but the possible effect of efficiency traits on visitation behaviour has rarely been addressed. Anther position, usually considered a trait that influences efficiency of pollen deposition on pollinators, was tested here for its effect on pollinator visitation rates and visit duration in flowers of wild radish, Raphanus raphanistrum . METHODS Artificial selection lines from two experiments that expanded the naturally occurring phenotypic variation in anther position were used. In one experiment, plant lines were selected either to increase or to decrease anther exsertion. The other experiment decreased anther dimorphism, which resulted in increased short stamen exsertion. The hypothesis was that increased exsertion would increase visitation of pollen foragers due to increased visual attraction. Another hypothesis was that exsertion of anthers above the corolla would interfere with nectar foragers and increase the duration of visit per flower. KEY RESULTS In the exsertion selection experiment, increased exsertion of both short and long stamens resulted in an increased number of fly visits per plant, and in the dimorphism experiment bee visits increased with increased short stamen exsertion. The duration of visits of nectar feeders declined significantly with increasing long stamen exsertion, which was opposite to the hypothesis. CONCLUSIONS Until now, anther position was considered to be an efficiency trait to enhance pollen uptake and deposition. Anther position in wild radish is shown here also to have an ecological significance in attracting pollen foragers. This study suggests an additional adaptive role for anther position beyond efficiency, and highlights the multiple ecological functions of floral traits in plant-pollinator interactions.
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Affiliation(s)
- Yuval Sapir
- The Botanical Garden, School of Plant Sciences and Food Security, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Keith Karoly
- Biology Department, Reed College, 3203 S.E. Woodstock Boulevard, Portland, OR 97202, USA
| | - Vanessa A Koelling
- Biology Department, Reed College, 3203 S.E. Woodstock Boulevard, Portland, OR 97202, USA
| | - Heather F Sahli
- Kellogg Biological Station and Department of Plant Biology, Michigan State University, 3700 East Gull Lake Drive, Hickory Corners, MI 49060, USA
| | - Frances N Knapczyk
- Kellogg Biological Station and Department of Plant Biology, Michigan State University, 3700 East Gull Lake Drive, Hickory Corners, MI 49060, USA
| | - Jeffrey K Conner
- Kellogg Biological Station and Department of Plant Biology, Michigan State University, 3700 East Gull Lake Drive, Hickory Corners, MI 49060, USA
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Huda AN, Salmah MRC, Hassan AA, Hamdan A, Razak MNA. Pollination Services of Mango Flower Pollinators. J Insect Sci 2015; 15:iev090. [PMID: 26246439 PMCID: PMC4672212 DOI: 10.1093/jisesa/iev090] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 07/05/2015] [Indexed: 06/04/2023]
Abstract
Measuring wild pollinator services in agricultural production is very important in the context of sustainable management. In this study, we estimated the contribution of native pollinators to mango fruit set production of two mango cultivars Mangifera indica (L). cv. 'Sala' and 'Chok Anan'. Visitation rates of pollinators on mango flowers and number of pollen grains adhering to their bodies determined pollinator efficiency for reproductive success of the crop. Chok Anan failed to produce any fruit set in the absence of pollinators. In natural condition, we found that Sala produced 4.8% fruit set per hermaphrodite flower while Chok Anan produced 3.1% per flower. Hand pollination tremendously increased fruit set of naturally pollinated flower for Sala (>100%), but only 33% for Chok Anan. Pollinator contribution to mango fruit set was estimated at 53% of total fruit set production. Our results highlighted the importance of insect pollinations in mango production. Large size flies Eristalinus spp. and Chrysomya spp. were found to be effective pollen carriers and visited more mango flowers compared with other flower visitors.
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Affiliation(s)
- A Nurul Huda
- School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - M R Che Salmah
- School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - A Abu Hassan
- School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - A Hamdan
- School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - M N Abdul Razak
- Faculty of Plantation and Agro-technology, Universiti Teknologi MARA, 02600 Arau, Perlis, Malaysia
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Delmas CEL, Escaravage N, Pornon A. Massive floral display affects insect visits but not pollinator-mediated pollen transfer in Rhododendron ferrugineum. Plant Biol (Stuttg) 2014; 16:234-243. [PMID: 23682673 DOI: 10.1111/plb.12039] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [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: 12/10/2012] [Accepted: 03/18/2013] [Indexed: 06/02/2023]
Abstract
Fragmentation of natural vegetation creates one of the largest threats to plant-pollinator interactions. Although fragmentation impacts on plant populations have been explored in many, mainly herbaceous, species, the response of wild mass-flowering species is poorly known. Here, we studied 28 heathland patches dominated by the mass-flowering shrub Rhododendron ferrugineum, each presenting different R. ferrugineum floral display sizes (total inflorescence number per patch) and patch isolation (median distance to the three nearest patches). We assessed the impacts of these two factors on (i) heathland patch visitor assemblage (considering R. ferrugineum versus surrounding community) and (ii) R. ferrugineum flower visitation rate and pollen transfer limitation (comparing seed set from emasculated to pollen-supplemented flowers). We found that diversity and abundance of bees visiting R. ferrugineum in heathland patches significantly decreased with decreasing R. ferrugineum floral display, while overall visitor density per patch and flower visitation rate increased. Moreover, a decrease in massive floral display and increase in patch isolation resulted in reduced visitor density in the surrounding community. Even in patches with few individuals, we found disproportionate visitor abundance in R. ferrugineum compared to the surrounding community. Finally, pollen transfer limitation in R. ferrugineum was neither affected by visitation rate nor by patch attributes. By disproportionally attracting pollinators from co-flowering species, and probably promoting geitonogamous pollen transfer, the mass-flowering trait appears adequate to compensate, in terms of conspecific pollen transfer, for the decrease in visitor diversity and abundance and in mate availability, which usually result from population fragmentation.
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Affiliation(s)
- C E L Delmas
- Université de Toulouse ENFA (Ecole Nationale de Formation Agronomique), UMR5174 EDB (Laboratoire Évolution & Diversité Biologique), F-31062, Toulouse, France
- CNRS (Centre National de la Recherche Scientifique), Université Paul Sabatier, UMR5174 EDB, F-31062, Toulouse, France
| | - N Escaravage
- Université de Toulouse ENFA (Ecole Nationale de Formation Agronomique), UMR5174 EDB (Laboratoire Évolution & Diversité Biologique), F-31062, Toulouse, France
- CNRS (Centre National de la Recherche Scientifique), Université Paul Sabatier, UMR5174 EDB, F-31062, Toulouse, France
| | - A Pornon
- Université de Toulouse ENFA (Ecole Nationale de Formation Agronomique), UMR5174 EDB (Laboratoire Évolution & Diversité Biologique), F-31062, Toulouse, France
- CNRS (Centre National de la Recherche Scientifique), Université Paul Sabatier, UMR5174 EDB, F-31062, Toulouse, France
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