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Tao J, Yang Y, Wang Q. Two Growing-Season Warming Partly Promoted Growth but Decreased Reproduction and Ornamental Value of Impatiens oxyanthera. PLANTS (BASEL, SWITZERLAND) 2024; 13:511. [PMID: 38498484 PMCID: PMC10892807 DOI: 10.3390/plants13040511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 02/06/2024] [Accepted: 02/09/2024] [Indexed: 03/20/2024]
Abstract
Climate warming profoundly affects the vegetative growth, flowering phenology and sexual reproduction of plants; therefore, it affects the ornamental value of wild flowers. Despite this, the extent and mechanism of the impact remain unclear. Here, we conducted a warming experiment for two growing seasons (increases of 1.89 °C in 2017 and 2.37 °C in 2018) with infrared heaters to examine the effects of warming on the ornamental value of the wild flower Impatiens oxyanthera, endemic to China, in Mount Emei. We evaluated the comprehensive ornamental value based on plant morphology and flowering characteristics using the analytic hierarchy process (AHP) and disentangled the impact of the two traits on ornamental value using principal component analysis (PCA) and the partial least squares structural equation model (PLS-SEM) under ambient and warming treatments. We hypothesized that warming would reduce the ornamental value of I. oxyanthera in terms of plant morphology and flowering traits. Our results showed that warming significantly decreased plant height and crown width and increased branch number and single-leaf area. Warming also decreased vexillum length, corolla tube length, nectar spur length and pedicel length. In addition, warming shortened flowering duration per plant and reduced flower number, while there was no significant effect on flower longevity and flower color at full-bloom stage between the control and warming treatment. Therefore, the comprehensive ornamental value under warming was lower than that under the control. Pedicel length, flower color, flower longevity and flowering duration per plant were the main factors affecting the comprehensive ornamental value. The PLS-SEM showed that warming had an indirect negative effect on ornamental value via direct negative effects on flowering traits. Collectively, these results indicate that, although promoting vegetative growth, short-term warming significantly decreased the ornamental value of I. oxyanthera due to warming-caused smaller flowers and shorter flowering duration.
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Affiliation(s)
- Jiayu Tao
- Southwest Key Laboratory of Wildlife Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China
| | - Youqin Yang
- Southwest Key Laboratory of Wildlife Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China
| | - Qiong Wang
- Southwest Key Laboratory of Wildlife Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China
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2
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Štenc J, Janošík L, Matoušková E, Hadrava J, Mikát M, Janovský Z. Pollinator visitation closely tracks diurnal patterns in pollen release. AMERICAN JOURNAL OF BOTANY 2023:e16179. [PMID: 37200483 DOI: 10.1002/ajb2.16179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 05/20/2023]
Abstract
PREMISE Animal-pollinated plants face a high risk of pollen loss during its transfer. To limit the negative effect of pollen losses by pollen consumption and heterospecific transfer, plant species may adjust and stratify their pollen availability during the day (i.e., "schedule" their pollen presentation) and attract pollinators in specific time frames. METHODS We investigated diurnal patterns of pollen availability and pollinator visitation in three coflowering plant species: Succisa pratensis with open flowers and accessible pollen, pollinated mainly by pollen-feeding hoverflies; Centaurea jacea with open flowers and less accessible pollen, pollinated mainly by pollen-collecting bees; and Trifolium hybridum with closed flowers and pollen accessible only after the active opening of the flower, pollinated exclusively by bees. RESULTS The three plant species differed in the peak pollen availability, tracked by the visitation activity of their pollinators. Succisa pratensis released all pollen in the morning, while pollinator activity was still low and peaked with a slight delay. In contrast, C. jacea and T. hybridum had distinct pollen presentation schedules, peaking in the early afternoon. The pollinator visitation to both of these species closely matched their pollen availability. CONCLUSIONS Stratifying pollen availability to pollinators during the day may be one of several mechanisms that allow coflowering plants to share their pollinators and decrease the probability of heterospecific pollen transfer.
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Affiliation(s)
- Jakub Štenc
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 41, Prague, Czech Republic
| | - Lukáš Janošík
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 41, Prague, Czech Republic
| | - Eva Matoušková
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, CZ-128 41, Prague, Czech Republic
| | - Jiří Hadrava
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, CZ-128 41, Prague, Czech Republic
| | - Michael Mikát
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, CZ-128 41, Prague, Czech Republic
- Department of Biology, Faculty of Science, York University, 4700 Keele Street, 203D, M3J 1P3, Toronto, Canada
- Department of General Zoology, Faculty of Natural Sciences 1-Biosciences, Martin Luther University, Hoher Weg 8, 06100 Halle (Saale), Germany
| | - Zdeněk Janovský
- Svatý Jan t. Krsovice 1, 285 04 Uhlířské Janovice, Czech Republic
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Wang H, Zhang ZQ, Zhang B, Wang LP, Guo W, Fang Y, Li QJ. Architectural effects regulate resource allocation within the inflorescences with nonlinear blooming patterns. AMERICAN JOURNAL OF BOTANY 2022; 109:1191-1202. [PMID: 35588305 DOI: 10.1002/ajb2.16001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 05/04/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
PREMISE Spatial and temporal resource allocations within inflorescences have been well-studied in many plants based on flowering sequence or floral position. However, there had been few attempts to investigate architectural effects and resource competition in species where the blooming pattern does not follow a linear positional pattern within the inflorescence. Moreover, most flowering plants show female-biased sex allocation in early or basal flowers, but it is unclear in species with inherent and changeless ovule production. METHODS We investigated intra-inflorescence variation in reproductive traits of Salvia przewalskii, a perennial herb with 4-ouvle ovary flowers and flowering sequence-floral position decoupled inflorescences. To detect the effects of resource competition and architectural effects on reproductive success, we manipulated inflorescence (removed floral buds by position and flowering sequence) and pollination (opened and supplemented pollination). RESULTS Pollen production and dry mass deceased from bottom to top flowers but did not significantly differ following flowering sequence, resulting in male-biased sex allocation in basal flowers. The seed production, fruit set, and bud development exhibited significant declining trends from proximal to distal positions regardless of the thinning and pollen treatments. Meanwhile, the seed production, fruit set, and bud development success did not significant differ when thinning was conducted according to flowering sequence. CONCLUSIONS Architectural effects plays a crucial role in resource allocation within decoupled flowering inflorescences. Moreover, our results highlighted that inherent floral traits such as changeless ovule production, may modify architectural effects on sex allocation.
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Affiliation(s)
- Hao Wang
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, and State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming, 650504, Yunnan, China
| | - Zhi-Qiang Zhang
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, and State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming, 650504, Yunnan, China
| | - Bo Zhang
- Key Laboratory of Grassland Ecosystem of Ministry of Education, and Sino-U.S. Centers for Grazingland Ecosystem Sustainability, College of Grassland Science, Gansu Agricultural University, Lanzhou, 730070, China
| | - Li-Ping Wang
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, and State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming, 650504, Yunnan, China
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Wen Guo
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, and State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming, 650504, Yunnan, China
| | - Ye Fang
- Shangri-La Alpine Botanical Garden, Diqing, 674400, China
| | - Qing-Jun Li
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, and State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming, 650504, Yunnan, China
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Ohashi K, Jürgens A, Thomson JD. Trade-off mitigation: a conceptual framework for understanding floral adaptation in multispecies interactions. Biol Rev Camb Philos Soc 2021; 96:2258-2280. [PMID: 34096158 PMCID: PMC8518848 DOI: 10.1111/brv.12754] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 05/15/2021] [Accepted: 05/18/2021] [Indexed: 11/26/2022]
Abstract
Explanations of floral adaptation to diverse pollinator faunas have often invoked visitor‐mediated trade‐offs in which no intermediate, generalized floral phenotype is optimal for pollination success, i.e. fitness valleys are created. In such cases, plant species are expected to specialize on particular groups of flower visitors. Contrary to this expectation, it is commonly observed that flowers interact with various groups of visitors, while at the same time maintaining distinct phenotypes among ecotypes, subspecies, or congeners. This apparent paradox may be due to a gap in our understanding of how visitor‐mediated trade‐offs could affect floral adaptation. Here we provide a conceptual framework for analysing visitor‐mediated trade‐offs with the hope of stimulating empirical and theoretical studies to fill this gap. We propose two types of visitor‐mediated trade‐offs to address negative correlations among fitness contributions of different visitors: visitor‐mediated phenotypic trade‐offs (phenotypic trade‐offs) and visitor‐mediated opportunity trade‐offs (opportunity trade‐offs). Phenotypic trade‐offs occur when different groups of visitors impose conflicting selection pressures on a floral trait. By contrast, opportunity trade‐offs emerge only when some visitors’ actions (e.g. pollen collection) remove opportunities for fitness contribution by more beneficial visitors. Previous studies have observed disruptive selection due to phenotypic trade‐offs less often than expected. In addition to existing explanations, we propose that some flowers have achieved ‘adaptive generalization’ by evolving features to avoid or eliminate the fitness valleys that phenotypic trade‐offs tend to produce. The literature suggests a variety of pathways to such ‘trade‐off mitigation’. Trade‐off mitigation may also evolve as an adaptation to opportunity trade‐offs. We argue that active exclusion, or floral specialization, can be viewed as a trade‐off mitigation, occurring only when flowers cannot otherwise avoid strong opportunity trade‐offs. These considerations suggest that an evolutionary strategy for trade‐off mitigation is achieved often by acquiring novel combinations of traits. Thus, phenotypic diversification of flowers through convergent evolution of certain trait combinations may have been enhanced not only through adaptive specialization for particular visitors, but also through adaptive generalization for particular visitor communities. Explorations of how visitor‐mediated trade‐offs explain the recurrent patterns of floral phenotypes may help reconcile the long‐lasting controversy on the validity of pollination syndromes.
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Affiliation(s)
- Kazuharu Ohashi
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan.,Department of Biology, Chemical Plant Ecology, Technische Universität Darmstadt, Schnittspahnstrasse 4, 64287 Darmstadt, Germany
| | - Andreas Jürgens
- Department of Biology, Chemical Plant Ecology, Technische Universität Darmstadt, Schnittspahnstrasse 4, 64287 Darmstadt, Germany
| | - James D Thomson
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Harbord St., Toronto, ON, M5S 3G5, Canada
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Optimal pollen stickiness to pollinators for maximizing paternal fitness: Increased number of recipient flowers or increased pollen deposition on recipient flowers? J Theor Biol 2021; 524:110731. [PMID: 33915145 DOI: 10.1016/j.jtbi.2021.110731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 03/31/2021] [Accepted: 04/16/2021] [Indexed: 11/22/2022]
Abstract
A plant can sire more seeds by increasing the number of pollen recipient flowers or the amount of pollen deposited on recipient flowers. We theoretically analyzed how pollen stickiness contributes to paternal fitness through changing the pattern of pollen dispersal including both the number of recipient flowers and overall pollen deposition (the overall amount of pollen deposited on recipient flowers) in animal-pollinated plants. We developed a numerical model in which pollen stickiness to pollinators increases with production of expensive materials on pollen surfaces, and a high level of stickiness diminishes the proportions of pollen lost from a pollinator body during a flight and pollen deposited on a stigma during a visit. We found that the number of recipient flowers monotonically increased with increasing pollen stickiness allocation while overall pollen deposition was maximized at a certain amount of stickiness allocation. We demonstrated that evolutionarily stable pollen stickiness attained many recipient flowers at the expense of overall pollen deposition in most cases while it merely favored maximization of overall pollen deposition in all other cases. Sticky pollen evolved if pollinators were highly likely to drop pollen during flights and did not diffuse well. In this situation, the evolutionarily stable pattern of pollen dispersal was acquisition of many pollen recipient flowers rather than maximization of overall pollen deposition. Sticky pollen also evolved if additional sticking elements were moderately effective in increasing the force of adhesion to pollinators. Pollen stickiness has a significant effect on the pattern of pollen dispersal via the extent of pollen carryover, and our results suggest that plants maximize paternal fitness by giving pollen the optimal stickiness, which varies with pollinating partners.
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Teixido AL, Duarte MO, Ballego-Campos I, Sanín D, Cunha JS, Oliveira CS, Silveira FAO. One for all and all for one: retention of colour-unchanged old flowers increases pollinator attraction in a hermaphroditic plant. PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:167-175. [PMID: 30184303 DOI: 10.1111/plb.12906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 08/27/2018] [Indexed: 06/08/2023]
Abstract
Long-lived flowers increase pollen transfer rates, but these entail high water and carbon maintenance costs. The retention of pollinated and reward-free old flowers enhances pollinator visitation to young receptive flowers by increasing floral display size. This mechanism is associated with acropetal inflorescences or changes in flower colour and openness, but the retention of unchanging solitary flowers remains overlooked. We examined pollination-dependent variation in floral longevity and determined stigmatic receptivity, pollen viability and pollen removal rates among flower ages in Kielmeyera regalis, a Neotropical savanna shrub. We also evaluated the effects of floral display size on pollinator visitation rates. Lastly, we determined whether old flowers are unvisited and exclusively increase pollinator attraction to young flowers through flower removal experiments. Regardless of pollination treatment, flowers lasted fully open with no detectable physical changes for 3 days. Over time, stigmas remained receptive but >95% of pollen was removed. Pollinator visitation significantly increased with floral display size and intermediate percentages (15-30%) of newly opened flowers. Accordingly, the retention of reward-free and unvisited old flowers increased young flower-pollinator interaction. Our results reveal the importance of a prolonged floral longevity in increasing pollinator attraction toward newly opened receptive flowers without changes in flower colour and form. We conclude that the retention of pollinated, reward-free and unvisited colour-unchanged old flowers in K. regalis is a strategy that counteracts the water use costs associated with the maintenance of large flowers with increased mate opportunities in a pollen-limited scenario.
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Affiliation(s)
- A L Teixido
- Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - M O Duarte
- Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - I Ballego-Campos
- Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - D Sanín
- Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - J S Cunha
- Departamento de Biologia Geral, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - C S Oliveira
- Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - F A O Silveira
- Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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7
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Tobe H, Huang YL, Kadokawa T, Tamura MN. Floral structure and development in Nartheciaceae (Dioscoreales), with special reference to ovary position and septal nectaries. JOURNAL OF PLANT RESEARCH 2018; 131:411-428. [PMID: 29569170 DOI: 10.1007/s10265-018-1026-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 02/26/2018] [Indexed: 06/08/2023]
Abstract
We present a comparative study of the floral structure and development of Nartheciaceae, a small dioscorealean family consisting of five genera (Aletris, Lophiola, Metanarthecium, Narthecium, and Nietneria). A noticeable diversity existed in nine floral characters. Analyses of their respective character states in the light of a phylogenetic context revealed that the flowers of Nartheciaceae, whose plesiomorphies occur in Aletris and Metanarthecium, have evolved toward in all or part of Lophiola, Narthecium, and Nietneria: (1) loss of a perianth tube; (2) stamen insertion at the perianth base; (3) congenital carpel fusion; (4) loss of the septal nectaries; (5) unilocular style; (6) unfused lateral carpellary margins in the style; (7) flower with the median outer tepal on the abaxial side; (8) flower with moniliform hairs; and (9) flower with weak monosymmetry. We further found that, as the flowers developed, the ovary shifted its position from inferior to superior. As a whole, their structure changes suggest that the Nartheciaceae flowers have evolved in close association with pollination and seed dispersal. By considering inferior ovaries and the presence of septal nectaries as plesiomorphies of Nartheciaceae, we discussed evolution of the ovary position and septal nectaries in all the monocots.
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Affiliation(s)
- Hiroshi Tobe
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan.
| | - Yu-Ling Huang
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan
- National Museum of Natural Science, Guancian Rd., Taichung, 404, Taiwan
| | - Tomoki Kadokawa
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan
| | - Minoru N Tamura
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan
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8
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Forrest JRK. Plant Size, Sexual Selection, and the Evolution of Protandry in Dioecious Plants. Am Nat 2014; 184:338-51. [DOI: 10.1086/677295] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Harder LD, Prusinkiewicz P. The interplay between inflorescence development and function as the crucible of architectural diversity. ANNALS OF BOTANY 2013; 112:1477-93. [PMID: 23243190 PMCID: PMC3828939 DOI: 10.1093/aob/mcs252] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
BACKGROUND Most angiosperms present flowers in inflorescences, which play roles in reproduction, primarily related to pollination, beyond those served by individual flowers alone. An inflorescence's overall reproductive contribution depends primarily on the three-dimensional arrangement of the floral canopy and its dynamics during its flowering period. These features depend in turn on characteristics of the underlying branching structure (scaffold) that supports and supplies water and nutrients to the floral canopy. This scaffold is produced by developmental algorithms that are genetically specified and hormonally mediated. Thus, the extensive inflorescence diversity evident among angiosperms evolves through changes in the developmental programmes that specify scaffold characteristics, which in turn modify canopy features that promote reproductive performance in a particular pollination and mating environment. Nevertheless, developmental and ecological aspects of inflorescences have typically been studied independently, limiting comprehensive understanding of the relations between inflorescence form, reproductive function, and evolution. SCOPE This review fosters an integrated perspective on inflorescences by summarizing aspects of their development and pollination function that enable and guide inflorescence evolution and diversification. CONCLUSIONS The architecture of flowering inflorescences comprises three related components: topology (branching patterns, flower number), geometry (phyllotaxis, internode and pedicel lengths, three-dimensional flower arrangement) and phenology (flower opening rate and longevity, dichogamy). Genetic and developmental evidence reveals that these components are largely subject to quantitative control. Consequently, inflorescence evolution proceeds along a multidimensional continuum. Nevertheless, some combinations of topology, geometry and phenology are represented more commonly than others, because they serve reproductive function particularly effectively. For wind-pollinated species, these combinations often represent compromise solutions to the conflicting physical influences on pollen removal, transport and deposition. For animal-pollinated species, dominant selective influences include the conflicting benefits of large displays for attracting pollinators and of small displays for limiting among-flower self-pollination. The variety of architectural components that comprise inflorescences enable diverse resolutions of these conflicts.
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Affiliation(s)
- Lawrence D. Harder
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- For correspondence. Email
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Marshall DL, Avritt JJ, Maliakal-Witt S, Medeiros JS, Shaner MGM. The impact of plant and flower age on mating patterns. ANNALS OF BOTANY 2010; 105:7-22. [PMID: 19875519 PMCID: PMC2794063 DOI: 10.1093/aob/mcp260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 08/18/2009] [Accepted: 09/18/2009] [Indexed: 05/06/2023]
Abstract
BACKGROUND Over a season, plant condition, amount of ongoing reproduction and biotic and abiotic environmental factors vary. As flowers age, flower condition and amount of pollen donated and received also vary. These internal and external changes are significant for fitness if they result in changes in reproduction and mating. SCOPE Literature from several fields was reviewed to provide a picture of the changes that occur in plants and flowers that can affect mating over a season. As flowers age, both the entire flower and individual floral whorls show changes in appearance and function. Over a season, changes in mating often appear as alteration in seed production vs. pollen donation. In several species, older, unpollinated flowers are more likely to self. If flowers are receiving pollen, staying open longer may increase the number of mates. In wild radish, for which there is considerable information on seed paternity, older flowers produce fewer seeds and appear to discriminate less among pollen donors. Pollen donor performance can also be linked to maternal plant age. Different pollinators and mates are available across the season. Also in wild radish, maternal plants appear to exert the most control over paternity when they are of intermediate age. CONCLUSIONS Although much is known about the characters of plants and flowers that can change over a season, there is less information on the effects of age on mating. Several studies document changes in self-pollination over time, but very few, other than those on wild radish, consider more subtle aspects of differential success of pollen donors over time.
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Affiliation(s)
- Diane L Marshall
- Department of Biology, University of New Mexico, MSC03 2020, Albuquerque, NM 87131, USA.
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Harder LD, Johnson SD. Adaptive plasticity of floral display size in animal-pollinated plants. Proc Biol Sci 2009; 272:2651-7. [PMID: 16321788 PMCID: PMC1559982 DOI: 10.1098/rspb.2005.3268] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Plants need not participate passively in their own mating, despite their immobility and reliance on pollen vectors. Instead, plants may respond to their recent pollination experience by adjusting the number of flowers that they display simultaneously. Such responsiveness could arise from the dependence of floral display size on the longevity of individual flowers, which varies with pollination rate in many plant species. By hand-pollinating some inflorescences, but not others, we demonstrate plasticity in display size of the orchid Satyrium longicauda. Pollination induced flower wilting, but did not affect the opening of new flowers, so that within a few days pollinated inflorescences displayed fewer flowers than unpollinated inflorescences. During subsequent exposure to intensive natural pollination, pollen removal and receipt increased proportionally with increasing display size, whereas pollen-removal failure and self-pollination accelerated. Such benefit-cost relations allow plants that adjust display size in response to the prevailing pollination rate to increase their attractiveness when pollinators are rare (large displays), or to limit mating costs when pollinators are abundant (small displays). Seen from this perspective, pollination-induced flower wilting serves the entire plant by allowing it to display the number of flowers that is appropriate for the current pollination environment.
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Affiliation(s)
- Lawrence D Harder
- Department of Biological Sciences, University of Calgary, Calgary, Alta. Canada T2N 1N4.
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Liao WJ, Hu Y, Zhu BR, Zhao XQ, Zeng YF, Zhang DY. Female reproductive success decreases with display size in monkshood, Aconitum kusnezoffii (Ranunculaceae). ANNALS OF BOTANY 2009; 104:1405-12. [PMID: 19767308 PMCID: PMC2778385 DOI: 10.1093/aob/mcp237] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2009] [Revised: 03/30/2009] [Accepted: 08/07/2009] [Indexed: 05/28/2023]
Abstract
BACKGROUND AND AIMS Reduction in female fitness in large clones can occur as a result of increased geitonogamous self-fertilization and its influence through inbreeding depression. This possibility was investigated in the self-compatible, bee-pollinated perennial herb Aconitum kusnezoffii which varies in clone size. METHODS Field investigations were conducted on pollinator behaviour, flowering phenology and variation in seed set. The effects of self-pollination following controlled self- and cross-pollination were also examined. Selfing rates of differently sized clones were assessed using allozyme markers. KEY RESULTS High rates of geitonogamous pollination were associated with large display size. Female fitness at the ramet level decreased with clone size. Fruit and seed set under cross-pollination were significantly higher than those under self-pollination. The pre-dispersal inbreeding depression was estimated as 0.502 based on the difference in seed set per flower between self- and cross-pollinated flowers. Selfing rates of differently sized clones did not differ. CONCLUSIONS It is concluded that in A. kusnezoffii the negative effects of self-pollination causing reduced female fertility with clone size arise primarily from a strong early-acting inbreeding depression leading to the abortion of selfed embryos prior to seed maturation.
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Affiliation(s)
| | | | | | | | | | - Da-Yong Zhang
- State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, Beijing Normal University, Beijing 100875, China
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Kudo G, Ishii HS, Hirabayashi Y, Ida TY. A test of the effect of floral color change on pollination effectiveness using artificial inflorescences visited by bumblebees. Oecologia 2007; 154:119-28. [PMID: 17674052 DOI: 10.1007/s00442-007-0820-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Accepted: 07/12/2007] [Indexed: 11/26/2022]
Abstract
Floral color change has been recognized as a pollination strategy, but its relative effectiveness has been evaluated insufficiently with respect to other floral traits. In this study, effects of floral color change on the visitation pattern of bumblebees were empirically assessed using artificial flowers. Four inflorescence types were postulated as strategies of flowering behavior: type 1 has no retention of old flowers, resulting in a small display size; type 2 retains old flowers without nectar production; type 3 retains old flowers with nectar; and type 4 retains color-changed old flowers without nectar. Effects of these treatments varied depending on both the total display size (single versus multiple inflorescences) and the pattern of flower-opening. In the single inflorescence experiment, a large floral display due to the retention of old flowers (types 2-4) enhanced pollinator attraction, and the number of flower visits per stay decreased with color change (type 4), suggesting a decrease in geitonogamous pollination. Type-4 plants also reduced the foraging time of bees in comparison with type-2 plants. In the multiple inflorescence experiment, the retention of old flowers did not contribute to pollinator attraction. When flowering occurred sequentially within inflorescences, type-4 plants successfully decreased the number of visits and the foraging time in comparison with type-2 plants. In contrast, floral color change did not influence the number of visits, and it extended the foraging time when flowering occurred simultaneously within inflorescences but the opening of inflorescences progressed sequentially within a plant. Therefore, the effectiveness of floral color change is highly susceptible to the display size and flowering pattern within plants, and this may limit the versatility of the color change strategy in nature.
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Affiliation(s)
- Gaku Kudo
- Graduate School of Environmental Earth Science, Hokkaido University, Sapporo, 060-0810, Japan.
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ISHII HS, HARDER LD. The size of individual Delphinium flowers and the opportunity for geitonogamous pollination. Funct Ecol 2006. [DOI: 10.1111/j.1365-2435.2006.01181.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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15
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Newman DA, Thomson JD. Effects of nectar robbing on nectar dynamics and bumblebee foraging strategies inLinaria vulgaris(Scrophulariaceae). OIKOS 2005. [DOI: 10.1111/j.0030-1299.2005.13884.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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16
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Miyake YC, Sakai S. Effects of number of flowers per raceme and number of racemes per plant on bumblebee visits and female reproductive success in Salvia nipponica (Labiatae). Ecol Res 2005. [DOI: 10.1007/s11284-004-0035-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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17
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Ishii HS. Increase of male reproductive components with size in an animal-pollinated hermaphrodite, Narthecium asiaticum (Liliaceae). Funct Ecol 2004. [DOI: 10.1111/j.1365-2435.2004.00826.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Evanhoe L, Galloway LF. Floral longevity in Campanula americana (Campanulaceae): a comparison of morphological and functional gender phases. AMERICAN JOURNAL OF BOTANY 2002; 89:587-591. [PMID: 21665659 DOI: 10.3732/ajb.89.4.587] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Plastic responses to pollination and/or pollen removal may shift a flower's realized longevity closer to an optimal longevity that maximizes reproductive output per unit resource input. In particular, conditional responses to pollen removal and pollen deposition are expected in flowers of protandrous species in which the lengths of the male and female phases may be adjusted independently. We investigated plasticity in floral longevity in Campanula americana, a protandrous, insect-pollinated herb. In greenhouse studies, we found that the longevity of the morphological male phase was shortened by pollen removal and that the longevity of the morphological female phase was shortened by pollen deposition. In a natural population, male and female sexual functions saturated within a few hours of morphological gender phase onset. In contrast to theory, morphological gender phases did not terminate immediately upon saturation of sexual function. These findings are discussed in the context of current floral longevity theory.
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Affiliation(s)
- Laurelin Evanhoe
- Mountain Lake Biological Station, University of Virginia, Charlottesville, Virginia 22904-4328 USA
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Ishii HS, Sakai S. Implications of geitonogamous pollination for floral longevity in Iris gracilipes. Funct Ecol 2001. [DOI: 10.1046/j.0269-8463.2001.00560.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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20
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