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Haghighatnia M, Machac A, Schmickl R, Lafon Placette C. Darwin's 'mystery of mysteries': the role of sexual selection in plant speciation. Biol Rev Camb Philos Soc 2023; 98:1928-1944. [PMID: 37337476 DOI: 10.1111/brv.12991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 06/02/2023] [Accepted: 06/07/2023] [Indexed: 06/21/2023]
Abstract
Sexual selection is considered one of the key processes that contribute to the emergence of new species. While the connection between sexual selection and speciation has been supported by comparative studies, the mechanisms that mediate this connection remain unresolved, especially in plants. Similarly, it is not clear how speciation processes within plant populations translate into large-scale speciation dynamics. Here, we review the mechanisms through which sexual selection, pollination, and mate choice unfold and interact, and how they may ultimately produce reproductive isolation in plants. We also overview reproductive strategies that might influence sexual selection in plants and illustrate how functional traits might connect speciation at the population level (population differentiation, evolution of reproductive barriers; i.e. microevolution) with evolution above the species level (macroevolution). We also identify outstanding questions in the field, and suitable data and tools for their resolution. Altogether, this effort motivates further research focused on plants, which might potentially broaden our general understanding of speciation by sexual selection, a major concept in evolutionary biology.
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Affiliation(s)
- Mohammadjavad Haghighatnia
- Department of Botany, Faculty of Science, Charles University, Benatska 2, Prague, CZ-128 01, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, Průhonice, 252 43, Czech Republic
| | - Antonin Machac
- Laboratory of Environmental Microbiology, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, Prague, 14220, Czech Republic
| | - Roswitha Schmickl
- Department of Botany, Faculty of Science, Charles University, Benatska 2, Prague, CZ-128 01, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, Průhonice, 252 43, Czech Republic
| | - Clément Lafon Placette
- Department of Botany, Faculty of Science, Charles University, Benatska 2, Prague, CZ-128 01, Czech Republic
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2
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Cisternas-Fuentes A, Dwyer R, Johnson N, Finnell L, Gilman J, Koski MH. Disentangling the components of pollen limitation in a widespread herb with gametophytic self-incompatibility. AMERICAN JOURNAL OF BOTANY 2023; 110:e16122. [PMID: 36571452 DOI: 10.1002/ajb2.16122] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
PREMISE Seed production is frequently limited by the receipt of insufficient or low-quality pollen, collectively termed "pollen limitation" (PL). In taxa with gametophytic self-incompatibility (GSI), incompatible pollen can germinate on stigmas but pollen tubes are arrested in styles. This allows for estimates of pollen performance before, during, and after self-recognition, as well as insight into the factors underlying pollen quality limitation in GSI taxa. METHODS We scored pollen performance following self and outcross pollinations in Argentina anserina to identify the location of self-recognition and establish the relationship between pollen tubes and seed production. We then estimated quantity and quality components of PL from >3300 field-collected styles. We combined our results with other studies to test the prediction that low pollen quality, but not quantity, drives higher PL in self-incompatible (SI) taxa than in self-compatible taxa (SC). RESULTS Self and outcross pollen germinated readily on stigmas, but 96% of germinated self-pollen was arrested during early tube elongation. Reproduction in the field was more limited by pollen quality than by quantity, and pollen failure near the location of self-recognition was a stronger barrier to fertilization than pollen germination. Across 26 taxa, SI species experienced stronger pollen quality, but not quantity, limitation than SC species. CONCLUSIONS Evaluating pollen performance at multiple points within pistils can elucidate potential causes of pollen quality limitation. The receipt of incompatible pollen inhibits fertilization success more than insufficient pollen receipt or poor pollen germination in A. anserina. Likewise, pollen quality limitation drives high overall PL in other SI taxa.
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Affiliation(s)
- Anita Cisternas-Fuentes
- Department of Biological Sciences, 132 Long Hall, Clemson University, Clemson, South Carolina, 29634, USA
| | - Roslynn Dwyer
- Department of Biological Sciences, 132 Long Hall, Clemson University, Clemson, South Carolina, 29634, USA
| | - Nicole Johnson
- Department of Biological Sciences, 132 Long Hall, Clemson University, Clemson, South Carolina, 29634, USA
| | - Lindsay Finnell
- Department of Biological Sciences, 132 Long Hall, Clemson University, Clemson, South Carolina, 29634, USA
| | - Jeffrey Gilman
- Department of Biological Sciences, 132 Long Hall, Clemson University, Clemson, South Carolina, 29634, USA
| | - Matthew H Koski
- Department of Biological Sciences, 132 Long Hall, Clemson University, Clemson, South Carolina, 29634, USA
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3
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Chemical constituents and phytochemical properties of floral maize pollen. PLoS One 2021; 16:e0247327. [PMID: 33626109 PMCID: PMC7906078 DOI: 10.1371/journal.pone.0247327] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/05/2021] [Indexed: 11/19/2022] Open
Abstract
Currently, bee-gathered pollen (bee pollen) is commonly used worldwide as a dietary supplement and is recognized for its curative properties. Floral pollen is also important but is less recognized due to a lack of investigation. This study aims to determine the morphological characteristics and nutritional and phytochemical properties of floral maize pollen. Fresh pollen grains harvested from a farm of maize plants are yellow in colour and spheroid in shape. They change to amber and indented prismatic solid shapes when dehydrated. The main composition of floral maize pollen is carbohydrates (44.30±3.73%), followed by moisture (23.38±5.73%), crude proteins (17.16±3.13%), crude fibres (9.56±0.92%), and ash (4.98±0.11%), while the lowest content is observed for crude fats (0.62±0.06%). The predominant mineral is potassium (768.50±11.40 mg 100 g-1), followed by sodium (695.10±9.70 mg 100 g-1), calcium (147.20±12.60 mg 100 g-1), and magnesium (97.30±2.9 mg 100 g-1). The microelements (with average values) consist of iron (49.50±3.30 mg 100 g-1) and zinc (30.00±3.70 mg 100 g-1). Excellent phytochemical properties add value to floral maize pollen. Maize pollen contains a high total phenolic content (TPC) and total flavonoid content (TFC) of 783.02 mg GAE 100 g-1 and 1706.83 mg QE 100 g-1, respectively, and possesses strong antioxidant activity of 10.54 mg mL-1. Maize floral pollen and derived products can serve as future food resources for human consumption and as a source of functional and bioactive compounds in nutraceutical and pharmaceutical industries.
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Varga S, Soulsbury CD. Environmental stressors affect sex ratios in sexually dimorphic plant sexual systems. PLANT BIOLOGY (STUTTGART, GERMANY) 2020; 22:890-898. [PMID: 32333831 DOI: 10.1111/plb.13125] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 03/29/2020] [Indexed: 06/11/2023]
Abstract
Revealing the environmental pressures determining the frequency of females amongst populations of sexually dimorphic plants is a key research question. Analyses of sex ratio variation have been mainly done in dioecious plants, which misses key plant sexual systems that might represent intermediate stages in the evolution of dioecy from hermaphroditism. We investigated female frequency across populations of sexually dimorphic plant species in relation to environmental stressors (temperature, precipitation), totaling 342 species, 2011 populations, representing 40 orders and three different sexual systems (dioecy, gynodioecy and subdioecy). We also included the biome where the population was located to test how female frequency may vary more broadly with climate conditions. After correcting for phylogeny, our results for gynodioecious systems showed a positive relationship between female frequency and increased environmental stress, with the main effects being temperature-related. Subdioecious systems also showed strong positive relationships with temperature, and positive and negative relationships related to precipitation, while no significant effects on sex ratio in dioecious plants were detected. Combined, we show that female frequencies in an intermediate sexual system on the pathway from hermaphroditism to dioecy respond strongly to environmental stressors and have different selective agents driving female frequency.
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Affiliation(s)
- S Varga
- School of Life Sciences, University of Lincoln, Joseph Banks Laboratories, Lincoln, LN6 7TS, UK
| | - C D Soulsbury
- School of Life Sciences, University of Lincoln, Joseph Banks Laboratories, Lincoln, LN6 7TS, UK
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5
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Pers-Kamczyc E, Tyrała-Wierucka Ż, Rabska M, Wrońska-Pilarek D, Kamczyc J. The higher availability of nutrients increases the production but decreases the quality of pollen grains in Juniperus communis L. JOURNAL OF PLANT PHYSIOLOGY 2020; 248:153156. [PMID: 32244105 DOI: 10.1016/j.jplph.2020.153156] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 03/11/2020] [Accepted: 03/11/2020] [Indexed: 06/11/2023]
Abstract
Next to global warming, excessive deposition of nitrogen has an alarming environmental impact on forest ecology, especially within dioecious species. Resource availability affects seed quality and can affect the distribution of plant species. Lower seed productivity can also be a result of limited pollen availability or lower pollen quality. A few studies have assessed the effect of nutrient availability on the quantity and quality of pollen grains produced. Therefore, rooted shoots of dioecious, male Juniperus communis L. grown in different nutritional conditions were used to assess the impact on productivity and quality attributes of produced pollen grains (pollen volume, morphology, germination, and chemical composition). The results indicated that nutrient availability impacts pollen grain development. Male plants growing in nutrient-rich environments appear to compensate for the lower quality of produced pollen grains by producing a higher number of male cones and thus a greater quantity of pollen. In contrast, the opposite was observed in plants growing in nutrient-poor environments. The availability of nitrogen and other nutrients will probably continue to impact soils in the foreseeable future due to anthropogenic activity and can be one of the drivers that can impact the reproduction and distribution of plants.
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Affiliation(s)
- Emilia Pers-Kamczyc
- Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland.
| | - Żanna Tyrała-Wierucka
- University of Zielona Góra, Faculty of Biological Sciences, Licealna 9, 65-417 Zielona Góra, Poland.
| | - Mariola Rabska
- Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland.
| | - Dorota Wrońska-Pilarek
- Poznan University of Life Sciences, Faculty of Forestry, Department of Forest Botany, Wojska Polskiego 71E, 60-625 Poznań, Poland.
| | - Jacek Kamczyc
- Poznan University of Life Sciences, Faculty of Forestry, Department of Game Management and Forest Protection, Wojska Polskiego 71C, 60-625 Poznań, Poland.
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6
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Christopher DA, Mitchell RJ, Karron JD. Pollination intensity and paternity in flowering plants. ANNALS OF BOTANY 2020; 125:1-9. [PMID: 31586397 PMCID: PMC6948204 DOI: 10.1093/aob/mcz159] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/06/2019] [Accepted: 10/01/2019] [Indexed: 05/10/2023]
Abstract
BACKGROUND Siring success plays a key role in plant evolution and reproductive ecology, and variation among individuals creates an opportunity for selection to act. Differences in male reproductive success can be caused by processes that occur during two stages, the pollination and post-pollination phases of reproduction. In the pollination phase, heritable variation in floral traits and floral display affect pollinator visitation patterns, which in turn affect variation among plants in the amount of pollen exported and deposited on recipient stigmas. In the post-pollination phase, differences among individuals in pollen grain germination success and pollen tube growth may cause realized paternity to differ from patterns of pollen receipt. The maternal plant can also preferentially provision some developing seeds or fruits to further alter variation in siring success. SCOPE In this review, we describe studies that advance our understanding of the dynamics of the pollination and post-pollination phases, focusing on how variation in male fitness changes in response to pollen limitation. We then explore the interplay between pollination and post-pollination success, and how these processes respond to ecological factors such as pollination intensity. We also identify pressing questions at the intersection of pollination and paternity and describe novel experimental approaches to elucidate the relative importance of pollination and post-pollination factors in determining male reproductive success. CONCLUSIONS The relative contribution of pollination and post-pollination processes to variation in male reproductive success may not be constant, but rather may vary with pollination intensity. Studies that quantify the effects of pollination and post-pollination phases in concert will be especially valuable as they will enable researchers to more fully understand the ecological conditions influencing male reproductive success.
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Affiliation(s)
- Dorothy A Christopher
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | | | - Jeffrey D Karron
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
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Alves CML, Noyszewski AK, Smith AG. Nicotiana tabacum pollen-pistil interactions show unexpected spatial and temporal differences in pollen tube growth among genotypes. PLANT REPRODUCTION 2019; 32:341-352. [PMID: 31359145 DOI: 10.1007/s00497-019-00375-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 07/12/2019] [Indexed: 06/10/2023]
Abstract
KEY MESSAGE This research revealed diverse PTG rates among intraspecific pollen-pistil interactions that showed variable dependency on the stigma and mature TT. Pollen-pistil interactions regulate pollen tube growth (PTG) rates and are determinants of fertilization and seed set. This research focuses on the diversity of intraspecific PTG rates and the spatial and temporal regulation of PTG among Nicotiana tabacum genotypes. Nonrandom mating within self-compatible species has been noted, but little is known on the mechanisms involved. To begin research on nonrandom mating, we took advantage of the model reproductive system of N. tabacum and used seventeen diverse N. tabacum genotypes in a complete pollination diallel to measure the diversity of intraspecific pollen-pistil interactions. The 289 intraspecific interactions showed surprisingly large differences in PTG rates. The interaction between specific males and females resulted in 18 specific combining abilities that were significantly different, indicating the importance of the specific genotype interaction in regulating intraspecific PTG. No single female or male genotype exerted overall control of PTG rates, as determined by a general combining ability analysis. Slow and fast pollen-pistil interactions showed spatial differences in growth rates along the style. Slower interactions had a slower initial PTG rate while fast interactions had faster consistent rates of growth indicating spatial regulation of PTG in the pistil. Removal of the stigma or the mature transmitting tissue (TT) showed the tissue-specific component of PTG regulation. Stigma removal resulted in slower or no change in PTG rate depending on the pollen and pistil genotypes. Removal of the TT, which necessitated removal of the stigma, showed no change, slower or unexpectedly, increased growth rates relative to growth rates without a stigma. These data show the diverse nature of pollen-pistil interactions in N. tabacum genotypes providing a system to further investigate the regulation of PTG.
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Affiliation(s)
- Camila M L Alves
- Department of Horticultural Science, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Andrzej K Noyszewski
- Department of Horticultural Science, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Alan G Smith
- Department of Horticultural Science, University of Minnesota, Saint Paul, MN, 55108, USA.
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Burbano Erazo E, Caetano CM. Maize plants grown on low pH soil incur plural meiotic abnormalities during microsporogenesis. THE NUCLEUS 2019. [DOI: 10.1007/s13237-018-0247-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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9
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Tonin R, Gerdol R, Tomaselli M, Petraglia A, Carbognani M, Wellstein C. Intraspecific Functional Trait Response to Advanced Snowmelt Suggests Increase of Growth Potential but Decrease of Seed Production in Snowbed Plant Species. FRONTIERS IN PLANT SCIENCE 2019; 10:289. [PMID: 30923530 PMCID: PMC6426784 DOI: 10.3389/fpls.2019.00289] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 02/21/2019] [Indexed: 06/09/2023]
Abstract
In ecological theory, it is currently unclear if intraspecific trait responses to environmental variation are shared across plant species. We use one of the strongest environmental variations in alpine ecosystems, i.e., advanced snowmelt due to climate warming, to answer this question for alpine snowbed plants. Snowbeds are extreme habitats where long-lasting snow cover represents the key environmental factor affecting plant life. Intraspecific variation in plant functional traits is a key to understanding the performance and vulnerability of species in a rapidly changing environment. We sampled snowbed species after an above-average warm winter to assess their phenotypic adjustment to advanced snowmelt, based on differences in the natural snowmelt dynamics with magnitudes reflecting predicted future warming. We measured nine functional traits related to plant growth and reproduction in seven vascular species, comparing snowbeds of early and late snowmelt across four snowbed sites in the southern Alps in Italy. The early snowbeds provide a proxy for the advanced snowmelt caused by climatic warming. Seed production was reduced under advanced snowmelt in all seed-forming snowbed species. Higher specific leaf area (SLA) and lower leaf dry matter content (LDMC) were indicative of improved growth potential in most seed-forming species under advanced snowmelt. We conclude, first, that in the short term, advanced snowmelt can improve snowbed species' growth potential. However, in the long term, results from other studies hint at increasing competition in case of ongoing improvement of conditions for plant growth under continued future climate warming, representing a risk for snowbed species. Second, a lower seed production can negatively affect the seed rain. A reduction of propagule pressure can be crucial in a context of loss of the present snowbed sites and the formation of new ones at higher altitudes along with climate warming. Finally, our findings encourage using plant functional traits at the intraspecific level across species as a tool to understand the future ecological challenges of plants in changing environments.
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Affiliation(s)
- Rita Tonin
- Faculty of Science and Technology, Free University of Bozen-Bolzano, Bolzano, Italy
| | - Renato Gerdol
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Marcello Tomaselli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Alessandro Petraglia
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Michele Carbognani
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Camilla Wellstein
- Faculty of Science and Technology, Free University of Bozen-Bolzano, Bolzano, Italy
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Minnaar C, Anderson B, de Jager ML, Karron JD. Plant-pollinator interactions along the pathway to paternity. ANNALS OF BOTANY 2019; 123:225-245. [PMID: 30535041 PMCID: PMC6344347 DOI: 10.1093/aob/mcy167] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 11/23/2018] [Indexed: 05/09/2023]
Abstract
Background The male fitness pathway, from pollen production to ovule fertilization, is thought to strongly influence reproductive trait evolution in animal-pollinated plants. This pathway is characterized by multiple avenues of pollen loss which may lead to reductions in male fitness. However, empirical data on the mechanistic processes leading to pollen loss during transport are limited, and we therefore lack a comprehensive understanding of how male fitness is influenced by each step in the pollination process. Scope This review assesses the history of studying male function in plants and identifies critical gaps in our understanding of the ecology and evolution of pollen transport. We explore male reproductive function along the steps of the pathway to paternity and discuss evolutionary options to overcome barriers to siring success. In particular, we present a newly emerging idea that bodies of pollinators function as a dynamic arena facilitating intense male-male competition, where pollen of rival males is constantly covered or displaced by competitors. This perspective extends the pollen-competitive arena beyond the confines of the stigma and style, and highlights the opportunity for important new breakthroughs in the study of male reproductive strategies and floral evolution.
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Affiliation(s)
- Corneile Minnaar
- Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
| | - Bruce Anderson
- Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
| | - Marinus L de Jager
- Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
| | - Jeffrey D Karron
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
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Lankinen Å, Lindström SAM, D’Hertefeldt T. Variable pollen viability and effects of pollen load size on components of seed set in cultivars and feral populations of oilseed rape. PLoS One 2018; 13:e0204407. [PMID: 30235318 PMCID: PMC6147549 DOI: 10.1371/journal.pone.0204407] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 09/07/2018] [Indexed: 11/19/2022] Open
Abstract
Pollination success is important for crop yield, but may be cultivar dependent. Less is known about which floral traits influence pollination success. Floral traits, e.g. traits related to attraction and reward, can also contribute to gene flow via pollen, the latter being of particular importance in oilseed rape (Brassica napus) where gene flow occurs between plants of crop, volunteer and feral origin as well as related taxa. We investigated the relationship between pollen load size and seed set in winter oilseed rape. We compared variability in pollen-viability traits, flower production (flowers from the main raceme times number of branches) and seed number and weight per siliqua among cultivars and feral populations (growing outside of agricultural fields) under controlled conditions. Both seed number and weight were saturated at relatively low pollen loads in the tested cultivar. Pollen viability and estimated flower production differed among cultivars, indicating that these traits could contribute to yield variability. Seed weight per siliqua, but not pollen traits or flower production, was lower in ferals compared to cultivars. Thus, while the probability of establishment may be reduced in ferals (due to lower seed weight per siliqua) this will not necessarily impact their contribution to gene flow via pollen. In oilseed rape a relatively low pollen load may be sufficient for full seed set in some cultivars, suggesting less dependence on insect pollination for high yield than generally expected. Our results also showed that previously less investigated floral traits, such as pollen viability, pollen tube growth rate and flower number, can differ between cultivars. Studies of these traits may provide targets for increasing crop yield and provide general knowledge about gene flow between cultivated, feral and related wild populations.
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Affiliation(s)
- Åsa Lankinen
- Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
- * E-mail:
| | - Sandra A. M. Lindström
- Biodiversity, Department of Biology, Lund University, Lund, Sweden
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Swedish Rural Economy and Agricultural Society in Scania, Kristianstad, Sweden
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12
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Lázaro A, Larrinaga AR. A multi-level test of the seed number/size trade-off in two Scandinavian communities. PLoS One 2018; 13:e0201175. [PMID: 30052656 PMCID: PMC6063417 DOI: 10.1371/journal.pone.0201175] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/10/2018] [Indexed: 01/09/2023] Open
Abstract
Seed size is a fundamental life-history trait for plants. A seed number/size trade-off is assumed because the resources invested in reproduction are limited; however, such a trade-off is not always observed. This could be a consequence of the method used for testing it, where the null hypothesis is dictated by common statistical practice, rather than being based on any underlying theory. Alternatively, there might be some population- and species-dependent variables that affect resource availability and, in turn, influence the presence and intensity of this trade-off. Using data on 42 herbs from two communities (lowland and alpine) from Southern Norway, we tested the validity of the classical linear model vs. two previously proposed models, based on resource competition, when assessing the existence of this trade-off at different levels. We also evaluated whether some species- (fruit aggregation, ovules/flower) and population-dependent (pollen limitation) variables could affect this trade-off. Classical linear modelling outperformed the other proposed functional models. Significant seed number/size relationships were negative in single-fruited species, whereas they were positive in species with infructescences of one-seeded fruits. Concordantly, fruit organization was the most influencing variable for the intra-specific trade-off in the lowland community. In the alpine community, species suffering higher pollen limitation showed more strongly negative slopes between seed size and seed number at the fruit/infructescence level. Across species, seed size and number were negatively related, although the relationship was significant in only one of the communities. No evidence of trade-off was found at the plant level. Linear models provide a flexible framework that allows coping with the variability in the seed number/size relationship. The emergence of the intra-specific relationship between seed number and size depends on species- and population-dependent variables, related to resource allocation and the pollination environment.
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Affiliation(s)
- Amparo Lázaro
- Global Change Research Group, Mediterranean Institute for Advanced Studies (UIB-CSIC), C/ Miquel Marqués 21, Esporles, Balearic Islands, Spain
| | - Asier R. Larrinaga
- eNeBaDa, Rúa das Penas 57, Santiago de Compostela, A Coruña, and Misión Biológica de Galicia (CSIC), Carballeira 8, Salcedo, Pontevedra, Spain
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13
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Rosbakh S, Pacini E, Nepi M, Poschlod P. An Unexplored Side of Regeneration Niche: Seed Quantity and Quality Are Determined by the Effect of Temperature on Pollen Performance. FRONTIERS IN PLANT SCIENCE 2018; 9:1036. [PMID: 30073009 PMCID: PMC6058057 DOI: 10.3389/fpls.2018.01036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 06/26/2018] [Indexed: 05/21/2023]
Abstract
In 1977, Peter Grubb introduced the regeneration niche concept, which assumes that a plant species cannot persist if the environmental conditions are only suitable for adult plant growth and survival, but not for seed production, dispersal, germination, and seedling establishment. During the last decade, this concept has received considerable research attention as it helps to better understand community assembly, population dynamics, and plant responses to environmental changes. Yet, in its present form, it focuses too much on the post-fertilization stages of plant sexual reproduction, neglecting the fact that the environment can operate as a constraint at many points in the chain of processes necessary for successful regeneration. In this review, we draw the attention of the plant ecology research community to the pre-fertilization stages of plant sexual reproduction, an almost ignored but important aspect of the regeneration niche, and their potential consequences for successful seed production. Particularly, we focus on how temperature affects pollen performance and determines plant reproduction success by playing an important role in the temporal and spatial variations in seed quality and quantity. We also review the pollen adaptations to temperature stresses at different levels of plant organization and discuss the plasticity of the performance of pollen under changing temperature conditions. The reviewed literature demonstrates that pre-fertilization stages of seed production, particularly the extreme sensitivity of male gametophyte performance to temperature, are the key determinants of a species' regeneration niche. Thus, we suggest that previous views stating that the regeneration niche begins with the production of seeds should be modified to include the preceding stages. Lastly, we identify several gaps in pollen-related studies revealing a framework of opportunities for future research, particularly how these findings could be used in the field of plant biology and ecology.
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Affiliation(s)
- Sergey Rosbakh
- Chair of Ecology and Conservation Biology, University of Regensburg, Regensburg, Germany
| | - Ettore Pacini
- Department of Life Sciences, University of Siena, Siena, Italy
| | - Massimo Nepi
- Department of Life Sciences, University of Siena, Siena, Italy
| | - Peter Poschlod
- Chair of Ecology and Conservation Biology, University of Regensburg, Regensburg, Germany
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Abstract
For the last 100 years, it has been uncontroversial to state that the plant germline is set aside late in development, but there is surprisingly little evidence to support this view. In contrast, much evolutionary theory and several recent empirical studies seem to suggest the opposite-that the germlines of some and perhaps most plants may be set aside early in development. But is this really the case? How much does it matter? How can we reconcile the new evidence with existing knowledge of plant development? And is there a way to reliably establish the timing of germline segregation in both model and nonmodel plants? Answering these questions is vital to understanding one of the most fundamental aspects of plant development and evolution.
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Affiliation(s)
- Robert Lanfear
- Ecology and Evolution, Research School of Biology, Australian National University, Canberra, Australia
- Biological Sciences, Macquarie University, Sydney, Australia
- * E-mail:
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15
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Distefano G, Gentile A, Hedhly A, La Malfa S. Temperatures during flower bud development affect pollen germination, self-incompatibility reaction and early fruit development of clementine (Citrus clementina Hort. ex Tan.). PLANT BIOLOGY (STUTTGART, GERMANY) 2018; 20:191-198. [PMID: 29106780 DOI: 10.1111/plb.12656] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 10/30/2017] [Indexed: 06/07/2023]
Abstract
One of the key environmental factors affecting plant reproductive systems is temperature. Characterising such effects is especially relevant for some commercially important genera such as Citrus. In this genus, failure of fertilisation results in parthenocarpic fruit development and seedlessness, which is a much-prized character. Here, we characterise the effects of temperature on flower and ovary development, and on pollen-pistil interactions in 'Comune' clementine (Citrus clementina Hort. ex Tan.). We examine flower bud development, in vitro pollen germination and pollen-pistil interaction at different temperatures (15, 20, 25 or 30 °C). These temperatures span the range from 'cold' to 'hot' weather during the flowering season in many citrus-growing regions. Temperature had a strong effect on flower and ovary development, pollen germination, and pollen tube growth kinetics. In particular, parthenocarpic fruit development (indicated by juice vesicle growth) was initiated early if flowers were exposed to warmer temperatures during anthesis. Exposure to different temperatures during flower bud development also alters expression of the self-incompatibility reaction. This affects the point in the pistil at which pollen tube growth is arrested and confirms the role of sub- and supra-optimal temperatures in determining the numbers of pollen tubes reaching the ovary.
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Affiliation(s)
- G Distefano
- Dipartimento di Agricoltura, Alimentazione e Ambiente, University of Catania, Catania, Italy
| | - A Gentile
- Dipartimento di Agricoltura, Alimentazione e Ambiente, University of Catania, Catania, Italy
| | - A Hedhly
- Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - S La Malfa
- Dipartimento di Agricoltura, Alimentazione e Ambiente, University of Catania, Catania, Italy
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16
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Mazer SJ, Hendrickson BT, Chellew JP, Kim LJ, Liu JW, Shu J, Sharma MV. Divergence in pollen performance between Clarkia sister species with contrasting mating systems supports predictions of sexual selection. Evolution 2018; 72:453-472. [PMID: 29359333 DOI: 10.1111/evo.13429] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 01/07/2018] [Accepted: 01/09/2018] [Indexed: 12/22/2022]
Abstract
Animal taxa that differ in the intensity of sperm competition often differ in sperm production or swimming speed, arguably due to sexual selection on postcopulatory male traits affecting siring success. In plants, closely related self- and cross-pollinated taxa similarly differ in the opportunity for sexual selection among male gametophytes after pollination, so traits such as the proportion of pollen on the stigma that rapidly enters the style and mean pollen tube growth rate (PTGR) are predicted to diverge between them. To date, no studies have tested this prediction in multiple plant populations under uniform conditions. We tested for differences in pollen performance in greenhouse-raised populations of two Clarkia sister species: the predominantly outcrossing C. unguiculata and the facultatively self-pollinating C. exilis. Within populations of each taxon, groups of individuals were reciprocally pollinated (n = 1153 pollinations) and their styles examined four hours later. We tested for the effects of species, population, pollen type (self vs. outcross), the number of competing pollen grains, and temperature on pollen performance. Clarkia unguiculata exhibited higher mean PTGR than C. exilis; pollen type had no effect on performance in either taxon. The difference between these species in PTGR is consistent with predictions of sexual selection theory.
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Affiliation(s)
- Susan J Mazer
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California 93106
| | - Brandon T Hendrickson
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California 93106
| | - Joseph P Chellew
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California 93106
| | - Lynn J Kim
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California 93106
| | - Jasen W Liu
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California 93106
| | - Jasper Shu
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California 93106
| | - Manju V Sharma
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California 93106
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17
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Bağcıoğlu M, Kohler A, Seifert S, Kneipp J, Zimmermann B. Monitoring of plant–environment interactions by high‐throughput
FTIR
spectroscopy of pollen. Methods Ecol Evol 2016. [DOI: 10.1111/2041-210x.12697] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Murat Bağcıoğlu
- Department of Mathematical Sciences and Technology Faculty of Environmental Science and Technology Norwegian University of Life Sciences 1432 Ås Norway
| | - Achim Kohler
- Department of Mathematical Sciences and Technology Faculty of Environmental Science and Technology Norwegian University of Life Sciences 1432 Ås Norway
- Nofima AS 1430 Ås Norway
| | - Stephan Seifert
- Department of Chemistry Humboldt‐Universität zu Berlin 12489 Berlin Germany
- BAM Federal Institute for Materials Research and Testing 12489 Berlin Germany
| | - Janina Kneipp
- Department of Chemistry Humboldt‐Universität zu Berlin 12489 Berlin Germany
- BAM Federal Institute for Materials Research and Testing 12489 Berlin Germany
| | - Boris Zimmermann
- Department of Mathematical Sciences and Technology Faculty of Environmental Science and Technology Norwegian University of Life Sciences 1432 Ås Norway
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18
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Lankinen Å, Hydbom S. Effects of soil resources on expression of a sexual conflict over timing of stigma receptivity in a mixed-mating plant. OIKOS 2016. [DOI: 10.1111/oik.03749] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Åsa Lankinen
- Plant Protection Biology; Swedish Univ. of Agricultural Sciences; PO Box 102 SE-230 53 Alnarp Sweden
| | - Sofia Hydbom
- Plant Protection Biology; Swedish Univ. of Agricultural Sciences; PO Box 102 SE-230 53 Alnarp Sweden
- Dept of Biology; Lund University; Ecology Building Lund Sweden
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19
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Lankinen Å, Strandh M. Differential selection on pollen and pistil traits in relation to pollen competition in the context of a sexual conflict over timing of stigma receptivity. AOB PLANTS 2016; 8:plw061. [PMID: 27562796 PMCID: PMC5063087 DOI: 10.1093/aobpla/plw061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 08/15/2016] [Indexed: 06/06/2023]
Abstract
Sexual conflict and its evolutionary consequences are understudied in plants, but the theory of sexual conflict may help explain how selection generates and maintains variability. Here, we investigated selection on pollen and pistil traits when pollen arrives sequentially to partially receptive pistils in relation to pollen competition and a sexual conflict over timing of stigma receptivity in the mixed-mating annual Collinsia heterophylla (Plantaginaceae). In this species the conflict is generated by early fertilizing pollen that reduces seed production, which is counteracted by delaying receptivity in the recipient. We performed sequential two-donor pollinations at early floral developmental stages involving two pollen deposition schedules (with or without a time lag of 1 day), using only outcross or self and outcross pollen. We investigated pollen and pistil traits in relation to siring success (male fitness) and seed production (female fitness). In contrast to previous findings in receptive pistils in C. heterophylla and in other species, last arriving pollen donors showed highest siring success in partially receptive pistils. The last male advantage was weaker when self pollen was the first arriving donor. Two measures of germination rate (early and late) and pollen tube growth rate of first arriving donors were important for siring success in crosses with a time lag, while only late germination rate had an effect in contemporary crosses. Curiously, late stigma receptivity was negatively related to seed production in our contemporary crosses, which was opposite to expectation. Our results in combination with previous studies suggest that pollen and pistil traits in C. heterophylla are differentially advantageous depending on stage of floral development and varying pollen deposition schedules. Variation in success of these traits over floral development time may result from sexually antagonistic selection.
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Affiliation(s)
- Åsa Lankinen
- Swedish University of Agricultural Sciences, Plant Protection Biology, PO Box 102, S-230 53 Alnarp, Sweden
| | - Maria Strandh
- Swedish University of Agricultural Sciences, Plant Protection Biology, PO Box 102, S-230 53 Alnarp, Sweden Department of Biology, Lund University, Ecology Building, S-223 62 Lund, Sweden
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20
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Yudakova OI, Tyrnov VS, Kunakh VA, Kozeretskaya IA, Parnikoza IY. Adaptation of the seed reproduction system to conditions of Maritime Antarctic in Deschampsia antarctica E. Desv. Russ J Dev Biol 2016. [DOI: 10.1134/s1062360416030073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Lankinen Å, Niss J, Madjidian JA. Effect of root contact on pollen competitive ability in a hermaphroditic winter-annual herb. Evol Ecol 2016. [DOI: 10.1007/s10682-016-9839-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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22
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Burkle LA, Runyon JB. Drought and leaf herbivory influence floral volatiles and pollinator attraction. GLOBAL CHANGE BIOLOGY 2016; 22:1644-54. [PMID: 26546275 DOI: 10.1111/gcb.13149] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 10/11/2015] [Accepted: 10/21/2015] [Indexed: 05/10/2023]
Abstract
The effects of climate change on species interactions are poorly understood. Investigating the mechanisms by which species interactions may shift under altered environmental conditions will help form a more predictive understanding of such shifts. In particular, components of climate change have the potential to strongly influence floral volatile organic compounds (VOCs) and, in turn, plant-pollinator interactions. In this study, we experimentally manipulated drought and herbivory for four forb species to determine effects of these treatments and their interactions on (1) visual plant traits traditionally associated with pollinator attraction, (2) floral VOCs, and (3) the visitation rates and community composition of pollinators. For all forbs tested, experimental drought universally reduced flower size and floral display, but there were species-specific effects of drought on volatile emissions per flower, the composition of compounds produced, and subsequent pollinator visitation rates. Moreover, the community of pollinating visitors was influenced by drought across forb species (i.e. some pollinator species were deterred by drought while others were attracted). Together, these results indicate that VOCs may provide more nuanced information to potential floral visitors and may be relatively more important than visual traits for pollinator attraction, particularly under shifting environmental conditions.
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Affiliation(s)
- Laura A Burkle
- Department of Ecology, Montana State University, Bozeman, MT, 59717, USA
| | - Justin B Runyon
- Rocky Mountain Research Station, USDA Forest Service, 1648 S. 7th Avenue, Bozeman, MT, 59717, USA
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23
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Hambä ck PA. Direct and indirect effects of herbivory: Feeding by spittlebugs affects pollinator visitation rates and seedset ofRudbeckia hirta. ECOSCIENCE 2016. [DOI: 10.1080/11956860.2001.11682629] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Swanson RJ, Hammond AT, Carlson AL, Gong H, Donovan TK. Pollen performance traits reveal prezygotic nonrandom mating and interference competition in Arabidopsis thaliana. AMERICAN JOURNAL OF BOTANY 2016; 103:498-513. [PMID: 26928008 DOI: 10.3732/ajb.1500172] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 10/01/2015] [Indexed: 06/05/2023]
Abstract
PREMISE The lack of ability to measure pollen performance traits in mixed pollinations has been a major hurdle in understanding the mechanisms of differential success of compatible pollen donors. In previous work, we demonstrated that nonrandom mating between two accessions of Arabidopsis thaliana, Columbia (Col) and Landsberg (Ler), is mediated by the male genotype. Despite these genetic insights, it was unclear at what stage of reproduction these genes were acting. Here, we used an experimental strategy that allowed us to differentiate different pollen populations in mixed pollinations to ask: (1) What pollen performance traits differed between Col and Ler accessions that direct nonrandom mating? (2) Is there evidence of interference competition? METHODS We used genetically marked pollen that can be visualized colorimetrically to quantify pollen performance of single populations of pollen in mixed pollinations. We used this and other assays to measure pollen viability, germination, tube growth, patterns of fertilization, and seed abortion. Finally, we assessed interference competition. RESULTS In mixed pollinations on Col pistils, Col pollen sired significantly more seeds than Ler pollen. Col pollen displayed higher pollen viability, faster and greater pollen germination, and faster pollen tube growth. We saw no evidence of nonrandom seed abortion. Finally, we found interference competition occurs in mixed pollinations. CONCLUSION The lack of differences in postzygotic processes coupled with direct observation of pollen performance traits indicates that nonrandom mating in Arabidopsis thaliana is prezygotic, due mostly to differential pollen germination and pollen tube growth rates. Finally, this study unambiguously demonstrates the existence of interference competition.
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Affiliation(s)
- Robert J Swanson
- Department of Biology, Valparaiso University, Valparaiso, Indiana 46383 USA
| | - Adam T Hammond
- Biophysical Sciences, The University of Chicago, Chicago, Illinois 60637 USA
| | - Ann L Carlson
- Department of Biology, Valparaiso University, Valparaiso, Indiana 46383 USA
| | - Hui Gong
- Department of Mathematics and Computer Science, Valparaiso University, Valparaiso, Indiana 46383 USA
| | - Thad K Donovan
- Smith Donovan Marketing & Communications, Chesterton, Indiana 46304 USA
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25
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McCallum B, Chang SM. Pollen competition in style: Effects of pollen size on siring success in the hermaphroditic common morning glory, Ipomoea purpurea. AMERICAN JOURNAL OF BOTANY 2016; 103:460-70. [PMID: 26905086 DOI: 10.3732/ajb.1500211] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/12/2015] [Indexed: 05/16/2023]
Abstract
PREMISE OF THE STUDY Pollen size varies greatly among flowering plant species and has been shown to influence the delivery of sperm cells to the eggs. Relatively little is known, however, about the functional significance of within-species genetic variation in pollen size. This study tests whether pollen size influences the relative siring success of a pollen donor during in vivo pollen competition experiments. METHODS We used two groups of Ipomoea purpurea plants genetically divergent in their pollen sizes and applied equal number of pollen grains from one large-pollen and one small-pollen donor onto the same stigma. Using microsatellite genetic markers, we identified the pollen parent of each of the resulting progeny to determine the relative siring success of the competing donors. Competitions between donors of equal-sized pollen served as a control. KEY RESULTS Differences in pollen size significantly affected the relative siring success of a pollen donor; larger-grained individuals outcompeted smaller-grained competitors but not equal-sized competitors. Relative siring success, however, sometimes varied across different pollen recipients. CONCLUSIONS Pollen size can influence the relative siring success of different individuals competing on the same stigma during postpollination processes. However, other factors, such as pollen-pistil interaction and environmental conditions, are likely to influence these competitions as well.
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Affiliation(s)
- Britnie McCallum
- Department of Plant Biology, University of Georgia, Athens, Georgia 30602 USA
| | - Shu-Mei Chang
- Department of Plant Biology, University of Georgia, Athens, Georgia 30602 USA
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26
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Marshall DL, Evans AS. Can selection on a male mating character result in evolutionary change? A selection experiment on California wild radish, Raphanus sativus. AMERICAN JOURNAL OF BOTANY 2016; 103:553-567. [PMID: 26872491 DOI: 10.3732/ajb.1500171] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 09/25/2015] [Indexed: 06/05/2023]
Abstract
PREMISE OF THE STUDY Whenever more pollen grains arrive on stigmas than necessary to fertilize ovules, sexual selection is possible. However, the role of sexual selection remains controversial, in part because of lack of evidence on genetic bases of traits and the response of relevant characters to selection. METHODS In an experiment with Raphanus sativus, we selected on tendency to sire seeds in the stylar or basal regions of fruits. This character is likely related to pollen tube growth rate, and seed position affects rates of abortion and seed predation. We measured differences among families in seed siring and related characters and evaluated responses to selection. KEY RESULTS All replicates showed strong effects of pollen donor family on proportion of seeds sired per fruit in mixed pollinations. Most also showed effects of pollen donor family on number of pollen grains per flower and pollen diameter. Two of four replicates showed a response to selection on position of seeds sired. In responding replicates, we found trade-offs in pollen grain size and number; plants with larger pollen grains sired more seeds in the basal region. CONCLUSIONS Our data suggest a genetic basis for pollen donor ability to sire seeds in competition. The significant response to selection in two replicates shows that position of seeds sired can respond to selection. Thus, all components for sexual selection to occur and affect traits are present. Variation in results among replicates might be due to changes in greenhouse conditions. Environmental effects may contribute to the maintenance of variation in these fitness-related characters.
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Affiliation(s)
- Diane L Marshall
- Department of Biology, MSC03-2020, 1 University of New Mexico, Albuquerque, New Mexico 87131 USA
| | - Ann S Evans
- Department of Biology, 99 Thomas Nelson Drive, Thomas Nelson Community College, Hampton, Virginia 23666 USA
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27
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Husband BC. Effect of inbreeding on pollen tube growth in diploid and tetraploid Chamerion angustifolium: Do polyploids mask mutational load in pollen? AMERICAN JOURNAL OF BOTANY 2016; 103:532-40. [PMID: 26944354 DOI: 10.3732/ajb.1500243] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 10/21/2015] [Indexed: 05/16/2023]
Abstract
PREMISE OF THE STUDY Deleterious recessive mutations are an important determinant of fitness (mutational load) in the sporophytic phase of plants and a major cause of inbreeding depression; however, their role in gametophyte function is less well documented but may account for variation in pollen tube growth and siring ability, especially between diploid and polyploid plants, which can mask the load. METHODS We investigated the role of mutational load in pollen performance using the perennial polyploid Chamerion angustifolium by comparing tube growth of pollen, in styles and in growth medium, from inbred (selfed) and outbred diploids to that of inbred and outbred tetraploids. Pollen from tetraploids is expected to mask deleterious mutations more effectively in the outbred condition but reveal them after inbreeding. In contrast, gametophytes from diploids should express the same genetic load in inbred or outbred plants. KEY RESULTS Pollen tube growth measured in growth medium was highest in outbred tetraploids and generally lower in inbred than outbred plants. The effect of selfing was significant in pollen from tetraploids but not diploids. The differential effect of selfing was also evident in the proportion of pollen reaching the base of styles, but the ploidy × pollination interaction was not significant. Selfing also had a negative effect on sporophyte fitness but was greater in diploids than tetraploids. CONCLUSIONS Pollen performance is influenced by the expression of mutational load, which is masked in polyploids. This effect may partly explain strong siring success of tetraploids in this species.
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Affiliation(s)
- Brian C Husband
- Department of Integrative Biology, University of Guelph, 50 Stone Road E., Guelph, Ontario, N1G 2W1 Canada
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28
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Reinhardt K, Dobler R, Abbott J. An Ecology of Sperm: Sperm Diversification by Natural Selection. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2015. [DOI: 10.1146/annurev-ecolsys-120213-091611] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Using basic ecological concepts, we introduce sperm ecology as a framework to study sperm cells. First, we describe environmental effects on sperm and conclude that evolutionary and ecological research should not neglect the overwhelming evidence presented here (both in external and internal fertilizers and in terrestrial and aquatic habitats) that sperm function is altered by many environments, including the male environment. Second, we determine that the evidence for sperm phenotypic plasticity is overwhelming. Third, we find that genotype-by-environment interaction effects on sperm function exist, but their general adaptive significance (e.g., local adaptation) awaits further research. It remains unresolved whether sperm diversification occurs by natural selection acting on sperm function or by selection on male and female microenvironments that enable optimal plastic performance of sperm (sperm niches). Environmental effects reduce fitness predictability under sperm competition, predict species distributions under global change, explain adaptive behavior, and highlight the role of natural selection in behavioral ecology and reproductive medicine.
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Affiliation(s)
- Klaus Reinhardt
- Applied Zoology, Department of Biology, Technische Universität Dresden, 01062 Dresden, Germany;,
| | - Ralph Dobler
- Applied Zoology, Department of Biology, Technische Universität Dresden, 01062 Dresden, Germany;,
| | - Jessica Abbott
- Department of Biology, Lund University, 223 62 Lund, Sweden
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29
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Li Y, Maki M. Variation in the frequency and extent of hybridization between Leucosceptrum japonicum and L. stellipilum (Lamiaceae) in the Central Japanese Mainland. PLoS One 2015; 10:e0116411. [PMID: 25738505 PMCID: PMC4349587 DOI: 10.1371/journal.pone.0116411] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 12/09/2014] [Indexed: 11/18/2022] Open
Abstract
Variations in the frequency and extent of hybridization among mixed populations located in the same contact zone provide natural laboratories for the study of extrinsic reproductive isolation maintaining species integrity. In this study, we examined the pattern of hybridization between L. japonicum and L. stellipilum among mixed populations in different localities of a contact zone. The genetic structures from three sympatric populations and six mixed populations in the hybrid zone, and five reference populations far from the contact zone, were characterized using 10 neutral nuclear microsatellite markers. Evidence from genetic distance-based clustering analysis, the frequency distribution of admixture proportion values, and the hybrid category assignment approaches indicated that the frequency and extent of hybridization varied considerably among populations in the contact zone between L. japonicum and L. stellipilum. One likely explanation is that variation in exogenous (ecological) selection among populations might contribute to differences in frequency and extent of hybridization. The present study will facilitate future research exploring the evolution of reproductive isolation between L. japonicum and L. stellipilum.
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Affiliation(s)
- Yue Li
- Division of Plant Evolutionary Biology, Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Aoba, Sendai 980–8578, Japan
- Botanical Gardens, Tohoku University, Kawauchi 12–2, Aoba, Sendai 980–0862, Japan
| | - Masayuki Maki
- Botanical Gardens, Tohoku University, Kawauchi 12–2, Aoba, Sendai 980–0862, Japan
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30
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Lagache L, Klein EK, Ducousso A, Petit RJ. Distinct male reproductive strategies in two closely related oak species. Mol Ecol 2014; 23:4331-43. [DOI: 10.1111/mec.12766] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 03/12/2014] [Accepted: 04/08/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Lélia Lagache
- INRA; UMR 1202 Biogeco; F-33610 Cestas France
- Univ. Bordeaux; UMR1202 Biogeco; F-33400 Talence France
| | - Etienne K. Klein
- Biostatistique et Processus Spatiaux (BioSP); INRA; UR546; F-84914 Avignon France
| | - Alexis Ducousso
- INRA; UMR 1202 Biogeco; F-33610 Cestas France
- Univ. Bordeaux; UMR1202 Biogeco; F-33400 Talence France
| | - Rémy J. Petit
- INRA; UMR 1202 Biogeco; F-33610 Cestas France
- Univ. Bordeaux; UMR1202 Biogeco; F-33400 Talence France
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Varga S, Vega-Frutis R, Kytöviita MM. Transgenerational effects of plant sex and arbuscular mycorrhizal symbiosis. THE NEW PHYTOLOGIST 2013; 199:812-821. [PMID: 23659431 DOI: 10.1111/nph.12305] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 04/02/2013] [Indexed: 06/02/2023]
Abstract
In gynodioecious plants, females are predicted to produce more and/or better offspring than hermaphrodites in order to be maintained in the same population. In the field, the roots of both sexes are usually colonized by arbuscular mycorrhizal (AM) fungi. Transgenerational effects of mycorrhizal symbiosis are largely unknown, although theoretically expected. We examined the maternal and paternal effects of AM fungal symbiosis and host sex on seed production and posterior seedling performance in Geranium sylvaticum, a gynodioecious plant. We hand-pollinated cloned females and hermaphrodites in symbiosis with AM fungi or in nonmycorrhizal conditions and measured seed number and mass, and seedling survival and growth in a glasshouse experiment. Females produced more seeds than hermaphrodites, but the seeds did not germinate, survive or grow better. Mycorrhizal plants were larger, but did not produce more seeds than nonmycorrhizal plants. Transgenerational parental effects of AM fungi were verified in seedling performance. This is the first study to show transgenerational mycorrhiza-mediated parental effects in a gynodioecious species. Mycorrhizal symbiosis affects plant fitness mainly through female functions with enduring effects on the next generation.
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Affiliation(s)
- Sandra Varga
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland.
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Hove AA, Mazer SJ. Pollen Performance in Clarkia Taxa with Contrasting Mating Systems: Implications for Male Gametophytic Evolution in Selfers and Outcrossers. PLANTS (BASEL, SWITZERLAND) 2013; 2:248-78. [PMID: 27137375 PMCID: PMC4844357 DOI: 10.3390/plants2020248] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 03/13/2013] [Accepted: 04/03/2013] [Indexed: 12/03/2022]
Abstract
We tested three predictions regarding the joint evolution of pollen performance and mating system. First, due to the potential for intense intrasexual competition in outcrossing populations, we predicted that outcrossers would produce faster-growing pollen than their selfing relatives. Second, if elevated competition promotes stronger selection on traits that improve pollen performance, then, among-plant variation in pollen performance would be lower in outcrossers than in selfers. Third, given successive generations of adaptation to the same maternal genotype in selfers, we predicted that, in selfing populations (but not in outcrossing ones), pollen would perform better following self- than cross-pollinations. We tested these predictions in field populations of two pairs of Clarkia (Onagraceae) sister taxa. Consistent with our predictions, one outcrosser (C. unguiculata) exhibited faster pollen germination and less variation in pollen tube growth rate (PTGR) among pollen donors than its selfing sister species, C. exilis. Contrary to our predictions, the selfing C. xantiana ssp. parviflora exhibited faster PTGR than the outcrossing ssp. xantiana, and these taxa showed similar levels of variation in this trait. Pollen performance following self- vs. cross-pollinations did not differ within either selfing or outcrossing taxa. While these findings suggest that mating system and pollen performance may jointly evolve in Clarkia, other factors clearly contribute to pollen performance in natural populations.
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Affiliation(s)
- Alisa A Hove
- Biology Department, Warren Wilson College, P.O. Box 9000, Asheville, NC 28815, USA.
| | - Susan J Mazer
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA.
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Schaeffer RN, Manson JS, Irwin RE. Effects of abiotic factors and species interactions on estimates of male plant function: a meta-analysis. Ecol Lett 2012; 16:399-408. [DOI: 10.1111/ele.12044] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 10/16/2012] [Accepted: 11/03/2012] [Indexed: 11/27/2022]
Affiliation(s)
- Robert N. Schaeffer
- Department of Biological Sciences; Dartmouth College; Hanover; NH; 03755; USA
| | | | - Rebecca E. Irwin
- Department of Biological Sciences; Dartmouth College; Hanover; NH; 03755; USA
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Lankinen Å, Larsson MC, Fransson AM. Allocation to pollen competitive ability versus seed production inViola tricoloras an effect of plant size, soil nutrients and presence of a root competitor. OIKOS 2012. [DOI: 10.1111/j.1600-0706.2012.00067.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Caruso CM, Case AL, Bailey MF. The evolutionary ecology of cytonuclear interactions in angiosperms. TRENDS IN PLANT SCIENCE 2012; 17:638-643. [PMID: 22784826 DOI: 10.1016/j.tplants.2012.06.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 06/08/2012] [Accepted: 06/13/2012] [Indexed: 06/01/2023]
Abstract
Interactions between cytoplasmic and nuclear genomes have significant evolutionary consequences. In angiosperms, the most common cytonuclear interaction is between mitochondrial genes that disrupt pollen production (cytoplasmic male sterility, CMS) and nuclear genes that restore it (nuclear male fertility restorers, Rf). The outcome of CMS/Rf interactions can depend on whether Rf alleles have negative pleiotropic effects on fitness. Although these fitness costs are often considered to be independent of the ecological context, we argue that the effects of Rf alleles on fitness should be context dependent. Thus, measuring the cost of restoration across a range of environments could help explain geographic and phylogenetic variation in the distribution of Rf alleles and the outcome of CMS/Rf interactions.
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Affiliation(s)
- Christina M Caruso
- Department of Integrative Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
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Lora J, Herrero M, Hormaza JI. Pollen performance, cell number, and physiological state in the early-divergent angiosperm Annona cherimola Mill. (Annonaceae) are related to environmental conditions during the final stages of pollen development. ACTA ACUST UNITED AC 2012; 25:157-67. [DOI: 10.1007/s00497-012-0187-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 04/18/2012] [Indexed: 12/01/2022]
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Steinacher G, Wagner J. Effect of temperature on the progamic phase in high-mountain plants. PLANT BIOLOGY (STUTTGART, GERMANY) 2012; 14:295-305. [PMID: 21973184 DOI: 10.1111/j.1438-8677.2011.00498.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Progamic processes are particularly temperature-sensitive and, in lowland plants, are usually drastically reduced below 10 °C and above 30 °C. Little is known about how effectively sexual processes of mountain plants function under the large temperature fluctuations at higher altitudes. The present study examines duration and thermal thresholds for progamic processes in six common plant species (Cerastium uniflorum, Gentianella germanica, Ranunculus alpestris, R. glacialis, Saxifraga bryoides, S. caesia) from different altitudinal zones in the European Alps. Whole plants were collected from natural sites shortly before anthesis and kept in a climate chamber until further processing. Flowers with receptive stigmas were hand-pollinated with allopollen and exposed to controlled temperatures between -2 and 40 °C. Pollen performance (adhesion to the stigma, germination, tube growth, fertilisation) was quantitatively analysed, using the aniline blue fluorescence method. Pollen adhesion was possible from -2 to 40 °C. Pollen germination and tube growth occurred from around 0 to 35 °C in most species. Fertilisation was observed from 5 to 30-32 °C (0-35 °C in G. germanica). The progamic phase was shortest in G. germanica (2 h at 30 °C, 12 h at 5 °C, 24 h at 0 °C), followed by R. glacialis (first fertilisation after 2 h at 30 °C, 18 h at 5 °C). In the remaining species, first fertilisation usually occurred after 4-6 h at 30 °C and after 24-30 h at 5 °C. Thus, mountain plants show remarkably flexible pollen performance over a wide temperature range and a short progamic phase, which may be essential for successful reproduction in the stochastic high-mountain climate.
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Affiliation(s)
- G Steinacher
- Faculty of Biology, Institute of Botany, University of Innsbruck, Innsbruck, Austria
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38
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Inbreeding depression in Solanum carolinense (Solanaceae) under field conditions and implications for mating system evolution. PLoS One 2011; 6:e28459. [PMID: 22174810 PMCID: PMC3236180 DOI: 10.1371/journal.pone.0028459] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 11/08/2011] [Indexed: 11/23/2022] Open
Abstract
The clonal weed Solanum carolinense exhibits plasticity in the strength of its self-incompatibility (SI) system and suffers low levels of inbreeding depression (δ) in the greenhouse. We planted one inbred and one outbred plant from each of eight maternal plants in a ring (replicated twice) and monitored clonal growth, herbivory, and reproduction over two years. Per ramet δ was estimated to be 0.63 in year one and 0.79 in year two, and outbred plants produced 2.5 times more ramets than inbred plants in the spring of year two. Inbred plants also suffered more herbivore damage than outbred plants in both fields, suggesting that inbreeding compromises herbivore resistance. Total per genet δ was 0.85 over the two years, indicating that S. carolinense is unlikely to become completely self-compatible, and suggesting that plasticity in the SI system is part of a stable mixed-mating system permitting self-fertilization when cross pollen limits seed production.
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Ejsmond MJ, Wrońska-Pilarek D, Ejsmond A, Dragosz-Kluska D, Karpińska-Kołaczek M, Kołaczek P, Kozłowski J. Does climate affect pollen morphology? Optimal size and shape of pollen grains under various desiccation intensity. Ecosphere 2011. [DOI: 10.1890/es11-00147.1] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Marshall DL, Tyler AP, Abrahamson NJ, Avritt JJ, Barnes MG, Larkin LL, Medeiros JS, Reynolds J, Shaner MGM, Simpson HL, Maliakal-Witt S. Pollen performance of Raphanus sativus (Brassicaceae) declines in response to elevated [CO(2)]. ACTA ACUST UNITED AC 2010; 23:325-36. [PMID: 20563606 DOI: 10.1007/s00497-010-0146-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 06/05/2010] [Indexed: 11/25/2022]
Abstract
Although increases in atmospheric [CO(2)] are known to affect plant physiology, growth and reproduction, understanding of these effects is limited because most studies of reproductive consequences focus solely on female function. Therefore, we examined the effects of CO(2) enrichment on male function in the annual Raphanus sativus. Pollen donors grown under elevated [CO(2)] initially sired a higher proportion of seeds per fruit than ambient [CO(2)]-grown plants when each was tested against two different standard competitors; however, by the end of the 5-month experiment, these pollen donors sired fewer seeds than ambient [CO(2)]-grown plants and produced a lower proportion of viable pollen grains. The results of this experiment confirm that elevated [CO(2)] can alter reproductive success. Additionally, the change in response to elevated [CO(2)] over time varied among pollen donor families; thus, changes in [CO(2)] could act as a selective force on this species.
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Affiliation(s)
- Diane L Marshall
- Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA.
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RAHMÉ J, WIDMER A, KARRENBERG S. Pollen competition as an asymmetric reproductive barrier between two closely relatedSilenespecies. J Evol Biol 2009; 22:1937-43. [DOI: 10.1111/j.1420-9101.2009.01803.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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42
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Mao YY, Huang SQ. Pollen resistance to water in 80 angiosperm species: flower structures protect rain-susceptible pollen. THE NEW PHYTOLOGIST 2009; 183:892-899. [PMID: 19563452 DOI: 10.1111/j.1469-8137.2009.02925.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Flowers exhibit adaptive responses to biotic and abiotic factors. It remains unclear whether pollen susceptibility to rain damage plays a role in the evolution of floral form. We investigated flower performance in rain and compared pollen longevity in dry conditions, pure water and solutions with different sucrose concentrations in 80 flowering species from 46 families with diverse floral shapes and pollination modes. A pollen viability test showed that pollen longevity in all studied species was greatly reduced by wetting. We found that pollen of species with complete protection by flower structures was susceptible to water damage and a high proportion of resistant pollen occurred in unprotected species. Flowers whose structures expose pollen to rain may also reduce rain damage through temporal patterns of pollen presentation. This prediction was supported by our direct measurement of pollen presentation duration on rainy days. Our observations showed that variation in pollen performance in water was associated with differences in floral forms. Water-resistant pollen and extended pollen presentation duration were favored by selection via rain contact in species in which pollen was not protected from rain. These findings support the functional hypothesis that flower structures protect susceptible pollen from rain, demonstrating that rain acts as a force shaping floral form.
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Affiliation(s)
- Yun-Yun Mao
- College of Life Sciences, Wuhan University, Wuhan 430072, China
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Li JK, Huang SQ. Flower thermoregulation facilitates fertilization in Asian sacred lotus. ANNALS OF BOTANY 2009; 103:1159-63. [PMID: 19282320 PMCID: PMC2707905 DOI: 10.1093/aob/mcp051] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS The thermoregulatory flower of the Asian sacred lotus (Nelumbo nucifera) can maintain a relatively stable temperature despite great variations in ambient temperature during anthesis. The thermoregulation has been hypothesized to offer a direct energy reward for pollinators in lotus flowers. This study aims to examine whether the stable temperature maintained in the floral chamber influences the fertilization process and seed development. METHODS An artificial refrigeration instrument was employed to cool flowers during the fertilization process and post-fertilization period in an experimental population. The effect of temperature on post-pollination events was also examined by removing petals in two field populations. KEY RESULTS Treatments with low floral temperature did not reduce stigma receptivity or pollen viability in undehisced anthers. Low temperature during the fertilization period significantly decreased seed set per flower but low temperature during the phase of seed development had no effect, suggesting that temperature regulation by lotus flowers facilitated fertilization success. Hand-pollination treatments in two field populations indicated that seed set of flowers with petals removed was lower than that of intact flowers in north China, where ambient temperatures are low, but not in south China, confirming that reducing the temperature of carpels did influence post-pollination events. CONCLUSIONS The experiments suggest that floral thermoregulation in lotus could enhance female reproductive success by facilitating fertilization.
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Lora J, Herrero M, Hormaza JI. The coexistence of bicellular and tricellular pollen in Annona cherimola (Annonaceae): Implications for pollen evolution. AMERICAN JOURNAL OF BOTANY 2009; 96:802-808. [PMID: 21628235 DOI: 10.3732/ajb.0800167] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Most angiosperms release bicellular pollen. However, in about one-third of extant angiosperms, the second pollen mitosis occurs before anthesis such that pollen is tricellular upon release. The shift from bicellular to tricellular development has occurred several times independently, but its causes are largely unknown. In this work, we observed the coexistence of both kinds of pollen at anther dehiscence in Annona cherimola, a species that belongs to the basal angiosperm family Annonaceae. Examination of pollen cell number during anther development showed that this coexistence was due to a late mitosis starting shortly before pollen shedding. Both types of pollen germinated equally well over the course of development. Because variable proportions of bicellular and tricellular pollen were observed at different sampling times, we tested the role of temperature by performing field and growth chamber experiments, which showed that higher temperatures near anthesis advanced the time of pollen mitosis II. The results show that selection could favor the production of tricellular pollen under certain environmental circumstances that prime rapid pollen germination and provide evidence of a system in which developmental variation persists, but that can be modified by external factors such as temperature.
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Affiliation(s)
- Jorge Lora
- Estación Experimental "La Mayora", CSIC 29760 Algarrobo-Costa, Málaga, Spain
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45
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Seymour RS, Ito Y, Onda Y, Ito K. Effects of floral thermogenesis on pollen function in Asian skunk cabbage Symplocarpus renifolius. Biol Lett 2009; 5:568-70. [PMID: 19364718 DOI: 10.1098/rsbl.2009.0064] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The effects of temperature on pollen germination and pollen tube growth rate were measured in vitro in thermogenic skunk cabbage, Symplocarpus renifolius Schott ex Tzvelev, and related to floral temperatures in the field. This species has physiologically thermoregulatory spadices that maintain temperatures near 23 degrees C, even in sub-freezing air. Tests at 8, 13, 18, 23, 28 and 33 degrees C showed sharp optima at 23 degrees C for both variables, and practically no development at 8 degrees C. Thermogenesis is therefore a requirement for fertilization in early spring. The narrow temperature tolerance is probably related to a long period of evolution in flowers that thermoregulate within a narrow range.
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Affiliation(s)
- Roger S Seymour
- Ecology and Evolutionary Biology, University of Adelaide, Adelaide, South Australia 5005, Australia.
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Hedhly A, Hormaza JI, Herrero M. Global warming and sexual plant reproduction. TRENDS IN PLANT SCIENCE 2009; 14:30-6. [PMID: 19062328 DOI: 10.1016/j.tplants.2008.11.001] [Citation(s) in RCA: 211] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Revised: 10/30/2008] [Accepted: 11/06/2008] [Indexed: 05/19/2023]
Abstract
The sexual reproductive phase in plants might be particularly vulnerable to the effects of global warming. The direct effect of temperature changes on the reproductive process has been documented previously, and recent data from other physiological processes that are affected by rising temperatures seem to reinforce the susceptibility of the reproductive process to a changing climate. But the reproductive phase also provides the plant with an opportunity to adapt to environmental changes. Understanding phenotypic plasticity and gametophyte selection for prevailing temperatures, along with possible epigenetic changes during this process, could provide new insights into plant evolution under a global-warming scenario.
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Affiliation(s)
- Afif Hedhly
- Departamento de Pomología, Estación Experimental de Aula Dei, CSIC, Zaragoza, 50059, Spain; Estación Experimental la Mayora, CSIC, Málaga, 29760, Spain.
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Swenson NG, Fair JM, Heikoop J. Water Stress and Hybridization between Quercus gambelii and Quercus grisea. WEST N AM NATURALIST 2008. [DOI: 10.3398/1527-0904-68.4.498] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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48
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Fishman L, Aagaard J, Tuthill JC. TOWARD THE EVOLUTIONARY GENOMICS OF GAMETOPHYTIC DIVERGENCE: PATTERNS OF TRANSMISSION RATIO DISTORTION IN MONKEYFLOWER (MIMULUS) HYBRIDS REVEAL A COMPLEX GENETIC BASIS FOR CONSPECIFIC POLLEN PRECEDENCE. Evolution 2008; 62:2958-70. [DOI: 10.1111/j.1558-5646.2008.00475.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Du D, Winsor JA, Smith M, Denicco A, Stephenson AG. Resistance and tolerance to herbivory changes with inbreeding and ontogeny in a wild gourd (Cucurbitaceae). AMERICAN JOURNAL OF BOTANY 2008; 95:84-92. [PMID: 21632318 DOI: 10.3732/ajb.95.1.84] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Herbivory is a ubiquitous component of terrestrial communities that reduces plant growth and reproduction. Consequently, a goal of evolutionary ecology is to identify the causes and consequences of variation in herbivory within plant populations. This three-year study examined the effects of inbreeding on the resistance of wild gourd plants (Cucurbita pepo subsp. texana) to herbivory by cucumber beetles and the impact of the timing of herbivory on reproduction. We grew families of inbred and outbred gourds and recorded beetle damage at three developmental stages, incidence of beetle-vectored wilt disease, survival, and reproduction. While total beetle damage significantly depressed flower and fruit production, damage until mid-July did not depress any measure of reproduction, indicating that these gourds are tolerant of moderate levels of herbivory for most of the growing season. However, beetle damage accumulating after mid-July significantly depressed reproduction, indicating that plants have reduced tolerance during peak reproduction. Early damage, however, did increase the probability of contracting a deadly wilt disease that is vectored by the beetles, suggesting that tolerance and resistance are not alternative defense strategies. Inbreeding significantly reduced resistance to herbivory and, independently of beetle damage, reproductive output. Finally, we found additive genetic variation for both resistance and tolerance that varies with ontogeny.
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Affiliation(s)
- Daolin Du
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania 16802 USA
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50
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Nakazato T, Jung MK, Housworth EA, Rieseberg LH, Gastony GJ. A genomewide study of reproductive barriers between allopatric populations of a homosporous fern, Ceratopteris richardii. Genetics 2007; 177:1141-50. [PMID: 17720917 PMCID: PMC2034619 DOI: 10.1534/genetics.107.076851] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Biological factors involved in reproductive barriers between two divergent races of Ceratopteris richardii were investigated. We used a combination of spore germination rates, QTL analysis of spore germination rates, and transmission ratio distortion (TRD) of 729 RFLPs, AFLPs, and isozyme markers distributed across the genome on the basis of hybrid populations of 488 doubled haploid lines (DHLs) and 168 F(2)'s. Substantial reproductive barriers were found between the parental races, predominantly in the form of spore inviability (23.7% F(1) spore viability). Intrinsic genetic factors such as Bateson-Dobzhansky-Muller (BDM) incompatibilities involving both nuclear-nuclear and nuclear-cytoplasmic factors and chromosomal rearrangements appear to contribute to intrinsic postzygotic isolation. The genomewide distribution patterns of TRD loci support the hypothesis that reproductive barriers are a byproduct of divergence in allopatry and that the strong reproductive barriers are attributable to a small number of genetic elements scattered throughout the genome.
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Affiliation(s)
- Takuya Nakazato
- Department of Biology, Indiana University, Bloomington, Indiana 47405-7005, USA.
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