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Surina B, Balant M, Glasnović P, Radosavljević I, Fišer Ž, Fujs N, Castro S. Population size as a major determinant of mating system and population genetic differentiation in a narrow endemic chasmophyte. BMC PLANT BIOLOGY 2023; 23:383. [PMID: 37553615 PMCID: PMC10411015 DOI: 10.1186/s12870-023-04384-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 07/18/2023] [Indexed: 08/10/2023]
Abstract
BACKGROUND Mating system is one of the major determinants of intra- and interspecific genetic structure, but may vary within and between plant populations. Our study model included all known populations of Moehringia tommasinii (Caryophyllaceae), a narrow endemic plant inhabiting rock crevices in the northwestern Adriatic, and some populations of co-occurring and widespread M. muscosa, an ecologically divergent relative with an overlapping flowering period. We performed reciprocal crosses within and between taxa and used molecular markers to assess the extent of gene flow within and between populations and taxa. Using coefficient of inbreeding, population size, seed weight, pollen-to-ovule ratio, and flower display size, we also looked for evidence of a selfing syndrome. RESULTS A surprisingly high variation in mating systems was observed among populations of M. tommasinii. These populations exhibited genetic structuring, with their size positively correlated with both seed weight and pollen production. Although a selfing syndrome could not be confirmed as the majority of selfing resulted from allogamous treatments, the occurrence of selfing was notable. In the presence of M. muscosa, at a site where both species coexist closely, a distinct pattern of fruit production was observed in M. tommasinii following various pollination treatments. Molecular and morphometric data provided evidence of hybridization followed by local extinction at this site. CONCLUSIONS Population size proved to be the most important factor affecting the mating system in genetically structured populations of M. tommasinii. Lighter seeds and lower pollen production observed in populations with pronounced selfing do not provide enough evidence for the selfing syndrome. Detected gene flow between M. tommasinii and the sympatric M. muscosa suggested weak reproductive barriers between the taxa, which could pose a conservation problems for the former species. Hybridization leading to local extinction may also resulted in floral polymorphism and disruption of mating patterns of M. tommasinii.
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Affiliation(s)
- Boštjan Surina
- Natural History Museum Rijeka, Lorenzov prolaz 1, 51000, Rijeka, Croatia.
- Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška 8, 6000, Koper, Slovenia.
| | - Manica Balant
- Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška 8, 6000, Koper, Slovenia
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s.n., Parc de Montjuïc, 08038, Barcelona, Spain
| | - Peter Glasnović
- Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška 8, 6000, Koper, Slovenia
| | - Ivan Radosavljević
- Division of Botany, Department of Biology, Faculty of Science, University of Zagreb, Marulićev trg 9a, 10000, Zagreb, Croatia
- Centre of Excellence for Biodiversity and Molecular Plant Breeding, Svetošimunska cesta 25, 10000, Zagreb, Croatia
| | - Živa Fišer
- Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška 8, 6000, Koper, Slovenia
| | - Nataša Fujs
- Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška 8, 6000, Koper, Slovenia
| | - Sílvia Castro
- Centre for Functional Ecology-Science for People & the Planet, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal
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Microhabitat and Pollinator Differentiation Drive Reproductive Isolation between Two Sympatric Salvia Species (Lamiaceae). PLANTS 2022; 11:plants11182423. [PMID: 36145824 PMCID: PMC9506227 DOI: 10.3390/plants11182423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/05/2022] [Accepted: 09/13/2022] [Indexed: 11/16/2022]
Abstract
Evaluation of multiple barriers contributing to reproductive isolation between sympatric plant species is key to understanding the mechanism of their coexistence; however, such investigations in biodiversity hotspots are still rare. In this study, we investigated and compared geography, microhabitat, phenology, flora, and pollinators, in addition to pollen–pistil interactions, seed production, and seed germination of the closely related sympatric Salvia digitaloides and S. flava on Yulong Snow Mountain, Southwestern Yunnan, China. The geographic distribution of these species overlapped, but their adaptation to physical and chemical properties of soil microhabitats differed. They shared the same flowering time but differed in flower size, style length, nectar volume, sugar concentration, and flower longevity. Both species shared bumblebees as effective pollinators, but flower constancy for the two species was relatively strong. Pollen tube growth, seed production, and seed germination were lower in interspecific than in intraspecific crosses. Our study suggested that microhabitat and pollinator isolation acted as the most important isolating barriers in maintaining the coexistence of the two Salvia species. Our study also highlighted that post-pollination barriers play an important role in preventing the gene flow between these two Salvia species.
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Delgado-Dávila R, Martén-Rodríguez S. A test of the reproductive assurance hypothesis in Ipomoea hederacea: does inbreeding depression counteract the benefits of self-pollination? AMERICAN JOURNAL OF BOTANY 2021; 108:2162-2173. [PMID: 34786691 DOI: 10.1002/ajb2.1794] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 07/15/2021] [Accepted: 07/19/2021] [Indexed: 06/13/2023]
Abstract
PREMISE Darwin proposed that self-pollination in allegedly outcrossing species might act as a reproductive assurance mechanism when pollinators or mates are scarce; however, in natural populations, the benefits of selfing may be opposed by seed discounting and inbreeding depression. While empirical studies show variation among species and populations in the magnitude of reproductive assurance, little is known about the counterbalancing effects of inbreeding depression. METHODS By comparing the female reproductive success of emasculated and open-pollinated flowers, we assessed the reproductive assurance hypothesis in two Mexican populations of Ipomoea hederacea. In one population, we assessed temporal variation in reproductive assurance for three years. We evaluated inbreeding depression on seed production, seedling germination, and dry plant mass by contrasting self- and cross-hand pollination treatments in one population for two years. RESULT The contribution of self-pollination to female reproductive success was high and consistent between populations, but there was variation in reproductive assurance across years. Inbreeding depression was absent in the early stages of progeny development, but there was a small negative effect of inbreeding in the probability of germination and the mass of adult progeny. CONCLUSIONS Self-pollination provided significant reproductive assurance in I. hederacea but this contribution was variable across time. The contribution of reproductive assurance is probably reduced by inbreeding depression in later stages of progeny development, but this counter effect was small in the study populations. This study supports the hypothesis that reproductive assurance with limited inbreeding depression is likely an important selective force in the evolution of self-pollination in the genus Ipomoea.
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Affiliation(s)
- Ruth Delgado-Dávila
- Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193, Spain
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores, unidad Morelia, Universidad Nacional Autónoma de México, 58089, Morelia, Michoacán, México
| | - Silvana Martén-Rodríguez
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores, unidad Morelia, Universidad Nacional Autónoma de México, 58089, Morelia, Michoacán, México
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Orsucci M, Sicard A. Flower evolution in the presence of heterospecific gene flow and its contribution to lineage divergence. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:971-989. [PMID: 33537708 DOI: 10.1093/jxb/eraa549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
Abstract
The success of species depends on their ability to exploit ecological resources in order to optimize their reproduction. However, species are not usually found within single-species ecosystems but in complex communities. Because of their genetic relatedness, closely related lineages tend to cluster within the same ecosystem, rely on the same resources, and be phenotypically similar. In sympatry, they will therefore compete for the same resources and, in the case of flowering plants, exchange their genes through heterospecific pollen transfer. These interactions, nevertheless, pose significant challenges to species co-existence because they can lead to resource limitation and reproductive interference. In such cases, divergent selective pressures on floral traits will favour genotypes that isolate or desynchronize the reproduction of sympatric lineages. The resulting displacement of reproductive characters will, in turn, lead to pre-mating isolation and promote intraspecific divergence, thus initiating or reinforcing the speciation process. In this review, we discuss the current theoretical and empirical knowledge on the influence of heterospecific pollen transfer on flower evolution, highlighting its potential to uncover the ecological and genomic constraints shaping the speciation process.
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Affiliation(s)
- Marion Orsucci
- Department of Plant Biology, Swedish University of Agricultural, Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
| | - Adrien Sicard
- Department of Plant Biology, Swedish University of Agricultural, Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
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Secondary Somatic Embryogenesis in Centaurium erythraea Rafn. PLANTS 2021; 10:plants10020199. [PMID: 33494461 PMCID: PMC7912690 DOI: 10.3390/plants10020199] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/11/2021] [Accepted: 01/14/2021] [Indexed: 12/21/2022]
Abstract
Somatic embryogenesis (SE) is a developmental process during which plant somatic cells, under suitable conditions, produce embryogenic cells that develop into somatic embryos (se). SE is the most important method for plant propagation in vitro, having both fundamental and applicative significance. SE can be induced from different tissues and organs, but when se are used as explants, the process is recognized as secondary or cyclic SE. We induced secondary SE in Centaurium erythraea by application of 2,4-dichlorophenoxyacetic acid (2,4-D) and N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU). A medium containing 0.1 mgL−1 2,4-D and 0.25 mgL−1 CPPU was optimal in terms of the number of primary SE explants forming se, the number of well-developed se per explant, and morphological appearance of the obtained se. These concentrations allowed SE to progress through three cycles, whereas at higher concentrations of 0.2 mgL−1 2,4-D and 0.5 mgL−1 CPPU, only two cycles were achieved. Histological analysis revealed that secondary se are formed both directly and indirectly. Secondary SE readily germinated and converted into plantlets. Induction of cyclic SE contributes to the conservation efforts of this endangered medicinal plant and expands the spectrum of in vitro developmental pathways described in centaury—an emerging model in developmental biology.
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Suetsugu K. Gynomonoecy in a mycoheterotrophic orchid Eulophia zollingeri with autonomous selfing hermaphroditic flowers and putatively outcrossing female flowers. PeerJ 2020; 8:e10272. [PMID: 33194432 PMCID: PMC7597633 DOI: 10.7717/peerj.10272] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/08/2020] [Indexed: 11/20/2022] Open
Abstract
Most orchid species exhibit an extreme case of hermaphroditism, owing to the fusion of male and female organs into a gynostemium. Exceptions to this rule have only been reported from the subtribes Catasetinae and Satyriinae. Here, I report an additional orchidaceous example whose flowers are not always hermaphroditic. In several Japanese populations of Eulophia zollingeri (Rchb.f.) J.J.Sm, a widespread Asian and Oceanian orchid, some flowers possess both the anther (i.e., anther cap and pollinaria) and stigma, whereas others possess only the stigma. Therefore, pollination experiments, an investigation of floral morphology and observations of floral visitors were conducted to understand the reproductive biology of E. zollingeri in Miyazaki Prefecture, Japan. It was confirmed that E. zollingeri studied here possesses a gynomonoecious reproductive system, a sexual system in which a single plant has both female flowers and hermaphroditic flowers. In addition, hermaphroditic flowers often possess an effective self-pollination system while female flowers could avoid autogamy but suffered from severe pollinator limitation, due to a lack of agamospermy and low insect-mediated pollination. The present study represents the first documented example of gynomonoecy within Orchidaceae. Gynomonoecy in E. zollingeri may be maintained by the tradeoff in reproductive traits between female flowers (with low fruit set but potential outcrossing benefits) and hermaphroditic flowers (with high fruit set but inbreeding depression in selfed offspring). This mixed mating is probably important in mycoheterotrophic E. zollingeri because it occurs in shaded forest understorey with a paucity of pollinators.
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Affiliation(s)
- Kenji Suetsugu
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
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Moreira-Hernández JI, Muchhala N. Importance of Pollinator-Mediated Interspecific Pollen Transfer for Angiosperm Evolution. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2019. [DOI: 10.1146/annurev-ecolsys-110218-024804] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Understanding how pollen moves between species is critical to understanding speciation, diversification, and evolution of flowering plants. For co-flowering species that share pollinators, competition through interspecific pollen transfer (IPT) can profoundly impact floral evolution, decreasing female fitness via heterospecific pollen deposition on stigmas and male fitness via pollen misplacement during visits to heterospecific flowers. The pollination literature demonstrates that such reproductive interference frequently selects for reproductive character displacement in floral traits linked to pollinator attraction, pollen placement, and mating systems and has also revealed that IPT between given pairs of species is typically asymmetric. More recent work is starting to elucidate its importance to the speciation process, clarifying the link between IPT and current and historical patterns of hybridization, the evolution of phenotypic novelty through adaptive introgression, and the rise of reproductive isolation. Our review aims to stimulate further research on IPT as a ubiquitous mechanism that plays a central role in angiosperm diversification.
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Affiliation(s)
- Juan Isaac Moreira-Hernández
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri–St. Louis, St. Louis, Missouri 63121, USA;,
| | - Nathan Muchhala
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri–St. Louis, St. Louis, Missouri 63121, USA;,
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Teixido AL, Aizen MA. Reproductive assurance weakens pollinator-mediated selection on flower size in an annual mixed-mating species. ANNALS OF BOTANY 2019; 123:1067-1077. [PMID: 30778517 PMCID: PMC6589515 DOI: 10.1093/aob/mcz014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 01/14/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND AND AIMS In animal-pollinated plants, direct and indirect selection for large and small flowers in predominantly outcrossing and selfing species, respectively, is a common consequence of pollen limitation (PL). However, many hermaphroditic species show a mixed-mating system known as delayed selfing, which provides reproductive assurance (RA) only when outcrossing is not realized. Although RA is expected to reduce pollinator-mediated selection towards larger flowers, the consequences of delayed selfing for selection on flower size in mixed-mating species remain overlooked. We investigated whether RA weakens selection on flower size in Tuberaria guttata, a mixed-mating annual herb. METHODS We related pollinator visitation rates to flower size and measured seed production in emasculated, hand cross-pollinated and intact (control) flowers in three natural populations. For each population, we estimated variation in PL and RA across individuals differing in flower size and phenotypic selection on this trait. KEY RESULTS Pollinator visitation increased and RA decreased with flower size in all populations. Increasing RA diminished but did not fully alleviate PL, because of early-acting inbreeding depression. In the least-visited and most pollen-limited population, RA increased seed production by >200 %, intensely counteracting the strong pollinator-mediated selection for larger corollas. In the most-visited population, however, RA increased seed production by an average of only 9 %. This population exhibited the largest fraction of individuals that showed a decrease in seed production due to selfing and the weakest pollinator-mediated selection on flower size. CONCLUSIONS The results suggest that the balance between the extent of RA and outcrossing contributes to determine flower size in mixed-mating systems. Pollinator-mediated selection favours larger flowers by increasing outcrossed seeds, but the benefits of RA greatly lessen this effect, especially under severe conditions of pollen limitation. Our findings also indicate that a mixed-mating system can represent an 'evolutionary trap' under an adequate pollinator supply.
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Affiliation(s)
- Alberto L Teixido
- Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, Madrid, Spain
| | - Marcelo A Aizen
- Grupo de Ecología de la Polinización, Universidad Nacional del Comahue and INIBIOMA-CONICET, Río Negro, Argentina
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Glasnović P, Temunović M, Lakušić D, Rakić T, Grubar VB, Surina B. Understanding biogeographical patterns in the western Balkan Peninsula using environmental niche modelling and geostatistics in polymorphic Edraianthus tenuifolius. AOB PLANTS 2018; 10:ply064. [PMID: 30425822 PMCID: PMC6220721 DOI: 10.1093/aobpla/ply064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/09/2018] [Indexed: 06/09/2023]
Abstract
The Balkan Peninsula represents one of the three southern European glacial refugia where biodiversity persisted throughout the climatically unstable Quaternary. This study considered the 'refugia within refugia' model, which assumes the environmental heterogeneity over time and space in larger refugia. To better understand patterns shaped during the Quaternary climatic oscillations, the present and last glacial maximum (LGM) environmental conditions and current morphological variability of Edraianthus tenuifolius, an endemic plant of the western Balkans with a well-known therphical structure, were considered. Potential present and LGM distributions were studied through environmental niche modelling using 161 data of occurrences and six bioclimatic variables, hindcasting the model to LGM conditions using three different global circulation models. To test the geographical variability of the reproductive region, 41 characters of 667 inflorescences from 35 populations within the distribution range were measured. Geographical patterns, using geostatistics together with univariate and multivariate statistical approaches, were analysed. The environmental niche model suggested the current potential distribution in correspondence to its known occurrences. The hindcast to LGM conditions suggested two separate areas of environmental suitability, one in the present-day northern Adriatic coast of Croatia (Istrian Peninsula, Kvarner) and another on the present-day south-eastern Adriatic coast (southern Dalmatia, Montenegro and northern Albania). Morphological variability showed a similar pattern, where southern populations separated from northern populations according to a major split in the central part of its distribution range (central Dalmatia). On other levels, stronger barriers were predicted to separate northern populations from the eastern Istrian Peninsula and the Kvarner area. The results suggested congruent biogeographical patterns to the already known phylogeographical structure. Both environmental niche modelling and the geographical variability of morphological characters suggested spatial partitioning, indicating the potential presence of two separate refugia during the LGM.
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Affiliation(s)
- Peter Glasnović
- Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška, Koper, Slovenia
| | - Martina Temunović
- Faculty of Forestry, Department of Forest Genetics, Dendrology and Botany, University of Zagreb, Svetošimunska, Zagreb, Croatia
| | - Dmitar Lakušić
- Faculty of Biology, Institute of Botany and Botanical Garden ‘Jevremovac’, University of Belgrade, Takovska, Belgrade, Serbia
| | - Tamara Rakić
- Faculty of Biology, Institute of Botany and Botanical Garden ‘Jevremovac’, University of Belgrade, Takovska, Belgrade, Serbia
| | | | - Boštjan Surina
- Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška, Koper, Slovenia
- Natural History Museum Rijeka, Lorenzov Prolaz, Rijeka, Croatia
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Mertens A, Brys R, Schouppe D, Jacquemyn H. The impact of floral morphology on genetic differentiation in two closely related biennial plant species. AOB PLANTS 2018; 10:ply051. [PMID: 30323915 PMCID: PMC6178171 DOI: 10.1093/aobpla/ply051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 09/05/2018] [Indexed: 06/08/2023]
Abstract
The genetic diversity and structure of plant populations are determined by the interaction of three distinct processes: gene flow, genetic drift and natural selection. These processes are to some extent dependent on the mating system of plants, which in turn is largely determined by floral morphology and the level of herkogamy in particular. In this study, we used molecular markers to investigate the impact of floral morphology on genetic differentiation and structure in two closely related Centaurium species that display large variation in floral morphology across two distinct geographic regions in Europe (mainland Europe and the UK). Our results showed that genetic differences between regions and populations within regions were similar for both species, but that patterns of genetic structure largely depended on the observed variation in floral morphology. Populations of Centaurium erythraea showed higher genetic differentiation and clear isolation by distance (IBD) in mainland Europe, but limited IBD in the UK. Opposite patterns were found in Centaurium littorale, with higher genetic differentiation and significant IBD in populations sampled in the UK and lower genetic differentiation in Continental populations with no pattern of IBD. Overall, these results indicate that variation in floral morphology has a profound impact on structuring of genetic diversity, with populations displaying low levels of herkogamy showing the strongest patterns of genetic structuring and the reverse pattern in populations showing high levels of herkogamy.
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Affiliation(s)
- Arne Mertens
- Department of Biology, Plant Conservation and Population Biology, KU Leuven, Leuven, Belgium
| | - Rein Brys
- Research Institute for Nature and Forest, Geraardsbergen, Belgium
| | - Dorien Schouppe
- Department of Biology, Plant Conservation and Population Biology, KU Leuven, Leuven, Belgium
| | - Hans Jacquemyn
- Department of Biology, Plant Conservation and Population Biology, KU Leuven, Leuven, Belgium
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Correlation between the timing of autonomous selfing and floral traits: a comparative study from three selfing Gentianopsis species (Gentianaceae). Sci Rep 2018; 8:3634. [PMID: 29483537 PMCID: PMC5827715 DOI: 10.1038/s41598-018-21930-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 02/13/2018] [Indexed: 11/11/2022] Open
Abstract
About 20% of angiosperms employ self-fertilization as their main mating strategy. In this study, we aimed to examine how the selfing timing correlated with floral traits in three Gentianopsis species in which autonomous selfing is achieved through filament elongation. Although the three Gentianopsis species exhibit no significant variation in their capacity for autonomous selfing, flowers of G. grandis last longer, are larger and have a higher corolla biomass, P/O ratios and male biomass allocation than those of G. paludosa, and especially those of G. contorta. Autonomous selfing occurs in the early floral life of G. paludosa and G. contorta and in the later floral life of G. grandis. Seed production mainly results from autonomous selfing in G. paludosa and G. contorta; however, G. grandis could be more described as having a mixed mating system. We suggest that autonomous selfing in later floral life increases the chance of cross-pollination prior to this, while autonomous selfing in early floral life offers a selective advantage to plants by reducing the resource investment in traits that may increase pollinator attraction and visitation.
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