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Sgambelluri LR, Jarvis JC, Kamel SJ. Multiple paternity, fertilization success, and male quality: Mating system variation in the eelgrass, Zostera marina. Ecol Evol 2024; 14:e11608. [PMID: 38919644 PMCID: PMC11197038 DOI: 10.1002/ece3.11608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 05/31/2024] [Accepted: 06/05/2024] [Indexed: 06/27/2024] Open
Abstract
Genetic diversity can modulate a population's response to a changing environment and plays a critical role in its ecological function. While multiple processes act to maintain genetic diversity, sexual reproduction remains the primary driving force. Eelgrass (Zostera marina) is an important habitat-forming species found in temperate coastal ecosystems across the globe. Recent increases in sea surface temperatures have resulted in shifts to a mixed-annual life-history strategy (i.e., displaying characteristics of both annual and perennial meadows) at its southern edge-of-range. Given that mating systems are intimately linked to standing levels of genetic variation, understanding the scope of sexual reproduction can illuminate the processes that shape genetic diversity. To characterize edge-of-range eelgrass mating systems, developing seeds on flowering Z. marina shoots were genotyped from three meadows in Topsail, North Carolina. In all meadows, levels of multiple mating were high, with shoots pollinated by an average of eight sires (range: 3-16). The number of fertilized seeds (i.e., reproductive success) varied significantly across sires (range: 1-25) and was positively correlated with both individual heterozygosity and self-fertilization. Outcrossing rates were high (approx. 70%) and varied across spathes. No clones were detected, and kinship among sampled flowering shoots was low, supporting observed patterns of reproductive output. Given the role that genetic diversity plays in enhancing resistance to and resilience from ecological disturbance, disentangling the links between life history, sexual reproduction, and genetic variation will aid in informing the management and conservation of this key foundation species.
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Affiliation(s)
- Lauren R. Sgambelluri
- Department of Biology and Marine Biology, Center for Marine ScienceUniversity of North Carolina WilmingtonWilmingtonNorth CarolinaUSA
| | - Jessie C. Jarvis
- Department of Biology and Marine Biology, Center for Marine ScienceUniversity of North Carolina WilmingtonWilmingtonNorth CarolinaUSA
| | - Stephanie J. Kamel
- Department of Biology and Marine Biology, Center for Marine ScienceUniversity of North Carolina WilmingtonWilmingtonNorth CarolinaUSA
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2
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Masaka K, Takada T. Transition model for the hermaphroditism-dioecy continuum in higher plants. Ecol Modell 2023. [DOI: 10.1016/j.ecolmodel.2022.110135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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3
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Lin X, Dong J, Yang Q, Zhou W, Wang Y, Zhang Y, Ahmad M, Sun Y, Wang Y, Ling J. Identification of three seagrass species in coral reef ecosystem by using multiple genes of DNA barcoding. ECOTOXICOLOGY (LONDON, ENGLAND) 2021; 30:919-928. [PMID: 33830383 DOI: 10.1007/s10646-021-02397-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/14/2021] [Indexed: 06/12/2023]
Abstract
Seagrasses constitute a significant part of coral reef ecosystems, representing high primary productivity and one of the most important coastal habitats in marine ecosystems. Though seagrasses possess irreplaceable ecological services to the marine environment, taxonomical ambiguity still exists due to similar morphological characters and phenotypic plasticity. As an emerging technology, DNA barcoding can effectively identify cryptic species using a short orthologous DNA region. In this study, we collected samples from five different locations (Daya Bay, Xincun Bay, Sanya Bay, Xisha Islands, and Nansha Islands), and three seagrass species Cymodocea rotundata, Thalassia hemprichii and Halophila ovalis was evaluated. Moreover, ITS, matK and rbcL genes were used as DNA barcodes. The results indicated that single ITS and concatenated ITS/matK/rbcL both conducted better species resolution than single matK and rbcL. Nevertheless, single ITS was more convenient. Furthermore, in all the four topology trees, three species resolved as 3 clusters as well H. ovalis and T. hemprichii grouped as sister clade. In the meantime, differentiation lay in intra-species based on the result of single ITS and three-locus analysis. Within H. ovalis and T. hemprichii separately, individuals from Xisha Islands first group together, then grouped with individuals from Nansha Islands and/or Xincun Bay and/or Sanya Bay and/or Daya Bay, which indicated that geographical distribution influenced population evolution. However, intra-species differentiation did not emerge in the tree of matK or rbcL.
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Affiliation(s)
- Xiancheng Lin
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Junde Dong
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
- Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences and Hainan Key Laboratory of Tropical Marine Biotechnology, Sanya, 572000, China
- Guangdong Science and Technology Library (Guangdong Institute of Scientific and Technical Information and Development Strategy), Guangzhou, 510070, China
| | - Qingsong Yang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences and Hainan Key Laboratory of Tropical Marine Biotechnology, Sanya, 572000, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Weiguo Zhou
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences and Hainan Key Laboratory of Tropical Marine Biotechnology, Sanya, 572000, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Yan Wang
- Guangdong Science and Technology Library (Guangdong Institute of Scientific and Technical Information and Development Strategy), Guangzhou, 510070, China
| | - Ying Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Manzoor Ahmad
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yingting Sun
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
| | - Youshao Wang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Juan Ling
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
- Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences and Hainan Key Laboratory of Tropical Marine Biotechnology, Sanya, 572000, China.
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, China.
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Students’ Word Associations with Different Terms Related to the Wadden Sea: Does the Place of Residence (Coast or Inland) Have an Influence? EDUCATION SCIENCES 2021. [DOI: 10.3390/educsci11060284] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
This paper presents students’ word associations with terms regarding the Wadden Sea. A continuous free word-association method was used in which the students from secondary schools (n = 3119, average age: 13.54 years) reported their associations with the stimulus words Wadden Sea, mudflat hiking tour, and tides in written form. Data were collected from students living close to the Wadden Sea and from students living inland. We performed a quantitative content analysis including the corresponding formation of categories. In addition, students’ school, out-of-school with the class, and private experiences the Wadden Sea ecosystem were recorded. The study shows that not only subject-related concepts should be considered at different levels, but non-subject-related aspects as well. The associations of the inland and non-inland students are statistically significantly different. The Wadden Sea and its biome were found to be completely unknown to some students. Students’ school, out-of-school with the class, and private experiences of the wetlands are also very mixed, regarding their Wadden Sea visitation frequency, and surprisingly cannot be directly derived from their place of residence. This research makes an important contribution towards the design of future biology didactic studies on the Wadden Sea.
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The Genetic Component of Seagrass Restoration: What We Know and the Way Forwards. WATER 2021. [DOI: 10.3390/w13060829] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Seagrasses are marine flowering plants providing key ecological services and functions in coasts and estuaries across the globe. Increased environmental changes fueled by human activities are affecting their existence, compromising natural habitats and ecosystems’ biodiversity and functioning. In this context, restoration of disturbed seagrass environments has become a worldwide priority to reverse ecosystem degradation and to recover ecosystem functionality and associated services. Despite the proven importance of genetic research to perform successful restoration projects, this aspect has often been overlooked in seagrass restoration. Here, we aimed to provide a comprehensive perspective of genetic aspects related to seagrass restoration. To this end, we first reviewed the importance of studying the genetic diversity and population structure of target seagrass populations; then, we discussed the pros and cons of different approaches used to restore and/or reinforce degraded populations. In general, the collection of genetic information and the development of connectivity maps are critical steps for any seagrass restoration activity. Traditionally, the selection of donor population preferred the use of local gene pools, thought to be the best adapted to current conditions. However, in the face of rapid ocean changes, alternative approaches such as the use of climate-adjusted or admixture genotypes might provide more sustainable options to secure the survival of restored meadows. Also, we discussed different transplantation strategies applied in seagrasses and emphasized the importance of long-term seagrass monitoring in restoration. The newly developed information on epigenetics as well as the application of assisted evolution strategies were also explored. Finally, a view of legal and ethical issues related to national and international restoration management is included, highlighting improvements and potential new directions to integrate with the genetic assessment. We concluded that a good restoration effort should incorporate: (1) a good understanding of the genetic structure of both donors and populations being restored; (2) the analysis of local environmental conditions and disturbances that affect the site to be restored; (3) the analysis of local adaptation constraints influencing the performances of donor populations and native plants; (4) the integration of distribution/connectivity maps with genetic information and environmental factors relative to the target seagrass populations; (5) the planning of long-term monitoring programs to assess the performance of the restored populations. The inclusion of epigenetic knowledge and the development of assisted evolution programs are strongly hoped for the future.
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Lloyd MW, Tumas HR, Neel MC. Limited pollen dispersal, small genetic neighborhoods, and biparental inbreeding in Vallisneria americana. AMERICAN JOURNAL OF BOTANY 2018; 105:227-240. [PMID: 29578290 DOI: 10.1002/ajb2.1031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 01/08/2018] [Indexed: 06/08/2023]
Abstract
PREMISE OF THE STUDY Pollen dispersal is a key process that influences ecological and evolutionary dynamics of plant populations by facilitating sexual reproduction and gene flow. Habitat loss and fragmentation have the potential to reduce pollen dispersal within and among habitat patches. We assessed aquatic pollen dispersal and mating system characteristics in Vallisneria americana-a water-pollinated plant with a distribution that has been reduced from historic levels. METHODS We examined pollen neighborhood size, biparental inbreeding, and pollen dispersal, based on seed paternity using the indirect paternity method KinDist, from samples of 18-39 mothers and 14-20 progeny per mother from three sites across 2 years. KEY RESULTS On average, fruits contained seeds sired by seven fathers. We found significant biparental inbreeding and limited pollen dispersal distances (0.8-4.34 m). However, in a number of cases, correlated paternity did not decline with distance, and dispersal could not be reliably estimated. CONCLUSIONS Frequent pollen dispersal is not expected among patches, and even within patches, gene flow via pollen will be limited. Limited pollen dispersal establishes genetic neighborhoods, which, unless overcome by seed and propagule dispersal, will lead to genetic differentiation even in a continuous population. Unless loss and fragmentation drive populations to extreme sex bias, local pollen dispersal is likely to be unaffected by habitat loss and fragmentation per se because the spatial scale of patch isolation already exceeds pollen dispersal distances. Therefore, managing specifically for pollen connectivity is only relevant over very short distances.
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Affiliation(s)
- Michael W Lloyd
- Department of Plant Science and Landscape Architecture and Department of Entomology, University of Maryland-College Park, 2116 Plant Sciences Building, College Park, Maryland, 20742-4452, USA
| | - Hayley R Tumas
- Department of Plant Science and Landscape Architecture and Department of Entomology, University of Maryland-College Park, 2116 Plant Sciences Building, College Park, Maryland, 20742-4452, USA
| | - Maile C Neel
- Department of Plant Science and Landscape Architecture and Department of Entomology, University of Maryland-College Park, 2116 Plant Sciences Building, College Park, Maryland, 20742-4452, USA
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Soissons LM, Haanstra EP, van Katwijk MM, Asmus R, Auby I, Barillé L, Brun FG, Cardoso PG, Desroy N, Fournier J, Ganthy F, Garmendia JM, Godet L, Grilo TF, Kadel P, Ondiviela B, Peralta G, Puente A, Recio M, Rigouin L, Valle M, Herman PMJ, Bouma TJ. Latitudinal Patterns in European Seagrass Carbon Reserves: Influence of Seasonal Fluctuations versus Short-Term Stress and Disturbance Events. FRONTIERS IN PLANT SCIENCE 2018; 9:88. [PMID: 29449859 PMCID: PMC5799261 DOI: 10.3389/fpls.2018.00088] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 01/15/2018] [Indexed: 05/21/2023]
Abstract
Seagrass meadows form highly productive and valuable ecosystems in the marine environment. Throughout the year, seagrass meadows are exposed to abiotic and biotic variations linked to (i) seasonal fluctuations, (ii) short-term stress events such as, e.g., local nutrient enrichment, and (iii) small-scale disturbances such as, e.g., biomass removal by grazing. We hypothesized that short-term stress events and small-scale disturbances may affect seagrass chance for survival in temperate latitudes. To test this hypothesis we focused on seagrass carbon reserves in the form of starch stored seasonally in rhizomes, as these have been defined as a good indicator for winter survival. Twelve Zostera noltei meadows were monitored along a latitudinal gradient in Western Europe to firstly assess the seasonal change of their rhizomal starch content. Secondly, we tested the effects of nutrient enrichment and/or biomass removal on the corresponding starch content by using a short-term manipulative field experiment at a single latitude in the Netherlands. At the end of the growing season, we observed a weak but significant linear increase of starch content along the latitudinal gradient from south to north. This agrees with the contention that such reserves are essential for regrowth after winter, which is more severe in the north. In addition, we also observed a weak but significant positive relationship between starch content at the beginning of the growing season and past winter temperatures. This implies a lower regrowth potential after severe winters, due to diminished starch content at the beginning of the growing season. Short-term stress and disturbances may intensify these patterns, because our manipulative experiments show that when nutrient enrichment and biomass loss co-occurred at the end of the growing season, Z. noltei starch content declined. In temperate zones, the capacity of seagrasses to accumulate carbon reserves is expected to determine carbon-based regrowth after winter. Therefore, processes affecting those reserves might affect seagrass resilience. With increasing human pressure on coastal systems, short- and small-scale stress events are expected to become more frequent, threatening the resilience of seagrass ecosystems, particularly at higher latitudes, where populations tend to have an annual cycle highly dependent on their storage capacity.
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Affiliation(s)
- Laura M. Soissons
- Department of Estuarine and Delta Systems, NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, Yerseke, Netherlands
| | - Eeke P. Haanstra
- Department of Estuarine and Delta Systems, NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, Yerseke, Netherlands
| | - Marieke M. van Katwijk
- Department of Environmental Science, Institute for Water and Wetland Research, Radboud University, Nijmegen, Netherlands
| | - Ragnhild Asmus
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
| | - Isabelle Auby
- Institut Français de Recherche pour l’Exploitation de la Mer – Laboratoire Environnement-Ressources d’Arcachon, Arcachon, France
| | - Laurent Barillé
- Equipe Mer-Molécules-Sante EA 2160, Faculté des Sciences et des Techniques, Université de Nantes, Nantes, France
| | - Fernando G. Brun
- Departamento de Biología, Área de Ecología, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Cádiz, Spain
| | - Patricia G. Cardoso
- Department of Life Sciences, Marine and Environmental Research Centre, University of Coimbra, Coimbra, Portugal
| | - Nicolas Desroy
- Institut Français de Recherche pour l’Exploitation de la Mer – Laboratoire Environnement et Ressources, Dinard, France
| | - Jerome Fournier
- Centre National de la Recherche Scientifique, UMR 7208 Biologie des Organismes et Ecosystèmes Aquatiques, Paris, France
| | - Florian Ganthy
- Institut Français de Recherche pour l’Exploitation de la Mer – Laboratoire Environnement-Ressources d’Arcachon, Arcachon, France
| | - Joxe-Mikel Garmendia
- Centro Tecnológico Experto en Innovación Marina y Alimentaria-Tecnalia, Marine Research Division, Pasaia, Spain
| | - Laurent Godet
- Centre National de la Recherche Scientifique, UMR 6554 Littoral, Environnement, Teledetection, Geomatique-Nantes Géolittomer, Université de Nantes, Nantes, France
| | - Tiago F. Grilo
- Marine and Environmental Sciences Centre, Laboratorio Maritimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal
| | - Petra Kadel
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
| | - Barbara Ondiviela
- Environmental Hydraulics Institute “IH Cantabria”, Universidad de Cantabria, Santander, Spain
| | - Gloria Peralta
- Departamento de Biología, Área de Ecología, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Cádiz, Spain
| | - Araceli Puente
- Environmental Hydraulics Institute “IH Cantabria”, Universidad de Cantabria, Santander, Spain
| | - Maria Recio
- Environmental Hydraulics Institute “IH Cantabria”, Universidad de Cantabria, Santander, Spain
| | - Loic Rigouin
- Institut Français de Recherche pour l’Exploitation de la Mer – Laboratoire Environnement-Ressources d’Arcachon, Arcachon, France
| | - Mireia Valle
- Centro Tecnológico Experto en Innovación Marina y Alimentaria-Tecnalia, Marine Research Division, Pasaia, Spain
- Escuela de Gestión Ambiental, Pontificia Universidad Católica del Ecuador Sede Esmeraldas – PUCESE, Esmeraldas, Ecuador
| | - Peter M. J. Herman
- Department of Estuarine and Delta Systems, NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, Yerseke, Netherlands
- Department of Environmental Science, Institute for Water and Wetland Research, Radboud University, Nijmegen, Netherlands
| | - Tjeerd J. Bouma
- Department of Estuarine and Delta Systems, NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, Yerseke, Netherlands
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Genetic divergence of the endangered seagrass Zostera japonica Ascherson & Graebner between temperate and subtropical coasts of China based on partial sequences of matK and ITS. BIOCHEM SYST ECOL 2016. [DOI: 10.1016/j.bse.2016.06.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Van Tussenbroek BI, Valdivia‐Carrillo T, Rodríguez‐Virgen IT, Sanabria‐Alcaraz SNM, Jiménez‐Durán K, Van Dijk KJ, Marquez‐Guzmán GJ. Coping with potential bi-parental inbreeding: limited pollen and seed dispersal and large genets in the dioecious marine angiosperm Thalassia testudinum. Ecol Evol 2016; 6:5542-5556. [PMID: 27942375 PMCID: PMC5127610 DOI: 10.1002/ece3.2309] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 05/31/2016] [Accepted: 06/23/2016] [Indexed: 12/02/2022] Open
Abstract
The high prevalence of dioecy in marine angiosperms or seagrasses (>50% of all species) is thought to enforce cross-fertilization. However, seagrasses are clonal plants, and they may still be subject to sibling-mating or bi-parental inbreeding if the genetic neighborhood is smaller than the size of the genets. We tested this by determining the genetic neighborhoods of the dioecious seagrass Thalassia testudinum at two sites (Back-Reef and Mid-Lagoon) in Puerto Morelos Reef Lagoon, Mexico, by measuring dispersal of pollen and seeds in situ, and by fine-scale spatial autocorrelation analysis with eight polymorphic microsatellite DNA markers. Prevalence of inbreeding was verified by estimating pairwise kinship coefficients; and by analysing the genotypes of seedlings grown from seeds in mesocosms. Average dispersal of pollen was 0.3-1.6 m (max. 4.8 m) and of seeds was 0.3-0.4 m (max. 1.8 m), resulting in a neighborhood area of 7.4 m2 (range 3.4-11.4 m2) at Back-Reef and 1.9 (range 1.87-1.92 m2) at Mid-Lagoon. Neighborhood area (Na) derived from spatial autocorrelation was 0.1-20.5 m2 at Back-Reef and 0.1-16.9 m2 at Mid-Lagoon. Maximal extensions of the genets, in 19 × 30 m plots, were 19.2 m (median 7.5 m) and 10.8 m (median 4.8 m) at Back-Reef and Mid-Lagoon. There was no indication of deficit or excess of heterozygotes nor were coefficients of inbreeding (FIS) significant. The seedlings did not show statistically significant deficit of heterozygotes (except for 1 locus at Back-Reef). Contrary to our expectations, we did not find evidence of bi-parental inbreeding in this dioecious seagrass with large genets but small genetic neighborhoods. Proposed mechanisms to avoid bi-parental inbreeding are possible selection against homozygotes during fecundation or ovule development. Additionally, the genets grew highly dispersed (aggregation index Ac was 0.09 and 0.10 for Back-Reef and Mid-Lagoon, respectively); such highly dispersed guerrilla-like clonal growth form likely increases the probability of crossing between different potentially unrelated genets.
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Affiliation(s)
- Brigitta Ine Van Tussenbroek
- Instituto de Ciencias del Mar y LimnologíaUnidad Académica Sistemas Arrecifales‐Puerto MorelosUniversidad Nacional Autónoma de MéxicoProlongación Niños Héroes S/NPuerto MorelosQuintana RooMéxico
| | - Tania Valdivia‐Carrillo
- Instituto de Ciencias del Mar y LimnologíaUnidad Académica Sistemas Arrecifales‐Puerto MorelosUniversidad Nacional Autónoma de MéxicoProlongación Niños Héroes S/NPuerto MorelosQuintana RooMéxico
| | - Irene Teresa Rodríguez‐Virgen
- Instituto de Ciencias del Mar y LimnologíaUnidad Académica Sistemas Arrecifales‐Puerto MorelosUniversidad Nacional Autónoma de MéxicoProlongación Niños Héroes S/NPuerto MorelosQuintana RooMéxico
- Present address: Department of Life and Health SciencesUniversity of North Texas at DallasDallasTexas
| | - Sylvia Nashieli Marisela Sanabria‐Alcaraz
- Instituto de Ciencias del Mar y LimnologíaUnidad Académica Sistemas Arrecifales‐Puerto MorelosUniversidad Nacional Autónoma de MéxicoProlongación Niños Héroes S/NPuerto MorelosQuintana RooMéxico
| | - Karina Jiménez‐Durán
- Instituto de Ciencias del Mar y LimnologíaUnidad Académica Sistemas Arrecifales‐Puerto MorelosUniversidad Nacional Autónoma de MéxicoProlongación Niños Héroes S/NPuerto MorelosQuintana RooMéxico
- Facultad de CienciasLaboratorio de Desarrollo de PlantasCiudad UniversitariaUniversidad Nacional Autónoma de MéxicoCoyoacanDistrito FederalMéxico
| | - Kor Jent Van Dijk
- Instituto de Ciencias del Mar y LimnologíaUnidad Académica Sistemas Arrecifales‐Puerto MorelosUniversidad Nacional Autónoma de MéxicoProlongación Niños Héroes S/NPuerto MorelosQuintana RooMéxico
- Present address: School of Biological ScienceUniversity of AdelaideAdelaideSouth Australia5005Australia
| | - Guadalupe Judith Marquez‐Guzmán
- Facultad de CienciasLaboratorio de Desarrollo de PlantasCiudad UniversitariaUniversidad Nacional Autónoma de MéxicoCoyoacanDistrito FederalMéxico
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10
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Van Tussenbroek BI, Soissons LM, Bouma TJ, Asmus R, Auby I, Brun FG, Cardoso PG, Desroy N, Fournier J, Ganthy F, Garmendia JM, Godet L, Grilo TF, Kadel P, Ondiviela B, Peralta G, Recio M, Valle M, Van der Heide T, Van Katwijk MM. Pollen limitation may be a common Allee effect in marine hydrophilous plants: implications for decline and recovery in seagrasses. Oecologia 2016; 182:595-609. [PMID: 27272209 DOI: 10.1007/s00442-016-3665-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 05/25/2016] [Indexed: 11/25/2022]
Abstract
Pollen limitation may be an important factor in accelerated decline of sparse or fragmented populations. Little is known whether hydrophilous plants (pollen transport by water) suffer from an Allee effect due to pollen limitation or not. Hydrophilous pollination is a typical trait of marine angiosperms or seagrasses. Although seagrass flowers usually have high pollen production, floral densities are highly variable. We evaluated pollen limitation for intertidal populations of the seagrass Zostera noltei in The Netherlands and found a significant positive relation between flowering spathe density and fruit-set, which was suboptimal at <1200 flowering spathes m(-2) (corresponding to <600 reproductive shoots m(-2)). A fragmented population had ≈35 % lower fruit-set at similar reproductive density than a continuous population. 75 % of all European populations studied over a large latitudinal gradient had flowering spathe densities below that required for optimal fruit-set, particularly in Southern countries. Literature review of the reproductive output of hydrophilous pollinated plants revealed that seed- or fruit-set of marine hydrophilous plants is generally low, as compared to hydrophilous freshwater and wind-pollinated plants. We conclude that pollen limitation as found in Z. noltei may be a common Allee effect for seagrasses, potentially accelerating decline and impairing recovery even after environmental conditions have improved substantially.
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Affiliation(s)
- B I Van Tussenbroek
- Department of Environmental Science, Institute for Wetland and Water Research, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
- Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Apdo Postal 1152, Cancún, Q. Roo, Mexico
| | - L M Soissons
- Department of Estuarine and Delta Systems (EDS), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, 4400 AC, Yerseke, The Netherlands.
| | - T J Bouma
- Department of Estuarine and Delta Systems (EDS), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, 4400 AC, Yerseke, The Netherlands
| | - R Asmus
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar-und Meeresforschung, Wadden Sea Station Sylt, Hafenstrasse 43, 25992, List, Germany
| | - I Auby
- IFREMER-LER/AR, Quai du Commandant Silhouette, 33120, Arcachon, France
| | - F G Brun
- Departamento de Biología, Área de Ecología, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Puerto Real, 11510, Cádiz, Spain
| | - P G Cardoso
- Department of Life Sciences, IMAR-Institute of Marine Research, University of Coimbra, 3004-517, Coimbra, Portugal
| | - N Desroy
- IFREMER-LER Dinard, 38 rue du Port Blanc, 35800, Dinard, France
| | - J Fournier
- UMR 7208 BOREA, Station de Biologie Marine MNHN, CNRS, Place de la Croix, BP 225, 29182, Concarneau Cedex, France
| | - F Ganthy
- IFREMER-LER/AR, Quai du Commandant Silhouette, 33120, Arcachon, France
| | - J M Garmendia
- Marine Research Division, AZTI-Tecnalia, Herrera Kaia Portualdea z/g, 20110, Pasaia, Spain
| | - L Godet
- CNRS, UMR 6554 LETG-Nantes Géolittomer, Université de Nantes, B.P. 81227, 44312, Nantes Cedex 3, France
| | - T F Grilo
- Department of Life Sciences, CFE-Centre for Functional Ecology, University of Coimbra, 3001-455, Coimbra, Portugal
| | - P Kadel
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar-und Meeresforschung, Wadden Sea Station Sylt, Hafenstrasse 43, 25992, List, Germany
| | - B Ondiviela
- Environmental Hydraulics Institute "IH Cantabria", Parque Científico y Tecnológico de Cantabria, Universidad de Cantabria, C/Isabel Torres No 15, 39011, Santander, Spain
| | - G Peralta
- Departamento de Biología, Área de Ecología, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Puerto Real, 11510, Cádiz, Spain
| | - M Recio
- Environmental Hydraulics Institute "IH Cantabria", Parque Científico y Tecnológico de Cantabria, Universidad de Cantabria, C/Isabel Torres No 15, 39011, Santander, Spain
| | - M Valle
- Marine Research Division, AZTI-Tecnalia, Herrera Kaia Portualdea z/g, 20110, Pasaia, Spain
- Central Research Department, Universidad Laica Eloy Alfaro de Manabí, Ciudadela Universitaria, vía San Mateo s/n, 13-05-2732, Manta, Manabí, Ecuador
| | - T Van der Heide
- Department of Aquatic Ecology and Environmental Biology, Institute for Wetland and Water Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - M M Van Katwijk
- Department of Environmental Science, Institute for Wetland and Water Research, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
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Jahnke M, Christensen A, Micu D, Milchakova N, Sezgin M, Todorova V, Strungaru S, Procaccini G. Patterns and mechanisms of dispersal in a keystone seagrass species. MARINE ENVIRONMENTAL RESEARCH 2016; 117:54-62. [PMID: 27085058 DOI: 10.1016/j.marenvres.2016.04.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 03/31/2016] [Accepted: 04/04/2016] [Indexed: 06/05/2023]
Abstract
Mechanisms and vectors of long-distance dispersal remain unknown for many coastal benthic species, including plants. Indications for the possibility for long-distance dispersal come from dispersal modelling and from genetic assessments, but have rarely been assessed with both methods. To this end, we assessed dispersal of the seagrass Zostera noltei, an important foundation species of the coastal zone. We investigate whether small scale seed dispersal and long-distance propagule dispersal do play a role for meta-population dynamics, using both genetic assessments based on eight microsatellite markers and physical modelling of ocean currents. Such assessments enhance our understanding of the biology and population dynamics of an important coastal foundation species. They are relevant for large scale conservation strategies as they give insights in the maintenance of genetic diversity and connectivity that may enhance resilience and resistance to stresses associated with seagrass loss.
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Affiliation(s)
- Marlene Jahnke
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy
| | - Asbjørn Christensen
- Technical University of Denmark, National Institute of Aquatic Resources, Jægersborg Allé 1, 2920 Charlottenlund, Denmark
| | - Dragos Micu
- National Institute for Marine Research and Development "Grigore Antipa", 900581 Constanţa, Romania
| | - Nataliya Milchakova
- The A.O. Kovalevsky Institute of Marine Biological Researches, 299011 Sevastopol, Russia
| | - Murat Sezgin
- Sinop University, Faculty of Fisheries, Department of Marine Biology and Ecology, TR57000 Sinop, Turkey
| | | | - Stefan Strungaru
- Alexandru Ioan Cuza University, Faculty of Biology, Department of Biology, Bd. Carol I 11, 700506 Iaşi, Romania
| | - Gabriele Procaccini
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
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12
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Kendrick GA, Orth RJ, Statton J, Hovey R, Ruiz Montoya L, Lowe RJ, Krauss SL, Sinclair EA. Demographic and genetic connectivity: the role and consequences of reproduction, dispersal and recruitment in seagrasses. Biol Rev Camb Philos Soc 2016; 92:921-938. [DOI: 10.1111/brv.12261] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 02/12/2016] [Accepted: 02/16/2016] [Indexed: 12/14/2022]
Affiliation(s)
- Gary A. Kendrick
- School of Plant Biology, Faculty of Science; University of Western Australia; Crawley Western Australia 6009 Australia
- UWA Oceans Institute; University of Western Australia; Crawley Western Australia 6009 Australia
| | - Robert J. Orth
- Virginia Institute of Marine Science; College of William and Mary; Gloucester Point VA 23062 U.S.A
| | - John Statton
- School of Plant Biology, Faculty of Science; University of Western Australia; Crawley Western Australia 6009 Australia
- UWA Oceans Institute; University of Western Australia; Crawley Western Australia 6009 Australia
| | - Renae Hovey
- School of Plant Biology, Faculty of Science; University of Western Australia; Crawley Western Australia 6009 Australia
- UWA Oceans Institute; University of Western Australia; Crawley Western Australia 6009 Australia
| | - Leonardo Ruiz Montoya
- School of Plant Biology, Faculty of Science; University of Western Australia; Crawley Western Australia 6009 Australia
- UWA Oceans Institute; University of Western Australia; Crawley Western Australia 6009 Australia
| | - Ryan J. Lowe
- UWA Oceans Institute; University of Western Australia; Crawley Western Australia 6009 Australia
- School of Earth and Environment; University of Western Australia; Crawley Western Australia 6009 Australia
- ARC Centre of Excellence for Coral Reef Studies; James Cook University Townsville; Queensland 4811 Australia
| | - Siegfried L. Krauss
- School of Plant Biology, Faculty of Science; University of Western Australia; Crawley Western Australia 6009 Australia
- Kings Park and Botanic Garden; West Perth Western Australia 6005 Australia
| | - Elizabeth A. Sinclair
- School of Plant Biology, Faculty of Science; University of Western Australia; Crawley Western Australia 6009 Australia
- UWA Oceans Institute; University of Western Australia; Crawley Western Australia 6009 Australia
- Kings Park and Botanic Garden; West Perth Western Australia 6005 Australia
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13
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Sinclair EA, Statton J, Hovey R, Anthony JM, Dixon KW, Kendrick GA. Reproduction at the extremes: pseudovivipary, hybridization and genetic mosaicism in Posidonia australis (Posidoniaceae). ANNALS OF BOTANY 2016; 117:237-247. [PMID: 26578720 PMCID: PMC4724040 DOI: 10.1093/aob/mcv162] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 08/12/2015] [Accepted: 09/04/2015] [Indexed: 06/05/2023]
Abstract
BACKGROUND AND AIMS Organisms occupying the edges of natural geographical ranges usually survive at the extreme limits of their innate physiological tolerances. Extreme and prolonged fluctuations in environmental conditions, often associated with climate change and exacerbated at species' geographical range edges, are known to trigger alternative responses in reproduction. This study reports the first observations of adventitious inflorescence-derived plantlet formation in the marine angiosperm Posidonia australis, growing at the northern range edge (upper thermal and salinity tolerance) in Shark Bay, Western Australia. These novel plantlets are described and a combination of microsatellite DNA markers and flow cytometry is used to determine their origin. METHODS Polymorphic microsatellite DNA markers were used to generate multilocus genotypes to determine the origin of the adventitious inflorescence-derived plantlets. Ploidy and genome size were estimated using flow cytometry. KEY RESULTS All adventitious plantlets were genetically identical to the maternal plant and were therefore the product of a novel pseudoviviparous reproductive event. It was found that 87 % of the multilocus genotypes contained three alleles in at least one locus. Ploidy was identical in all sampled plants. The genome size (2 C value) for samples from Shark Bay and from a separate site much further south was not significantly different, implying they are the same ploidy level and ruling out a complete genome duplication (polyploidy). CONCLUSIONS Survival at range edges often sees the development of novel responses in the struggle for survival and reproduction. This study documents a physiological response at the trailing edge, whereby reproductive strategy can adapt to fluctuating conditions and suggests that the lower-than-usual water temperature triggered unfertilized inflorescences to 'switch' to growing plantlets that were adventitious clones of their maternal parent. This may have important long-term implications as both genetic and ecological constraints may limit the ability to adapt or range-shift; this seagrass meadow in Shark Bay already has low genetic diversity, no sexual reproduction and no seedling recruitment.
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Affiliation(s)
- Elizabeth A Sinclair
- School of Plant Biology, University of Western Australia, Crawley 6009, Western Australia, Kings Park and Botanic Gardens, West Perth 6005, Western Australia, Oceans Institute, University of Western Australia, Crawley 6009, Western Australia and
| | - John Statton
- School of Plant Biology, University of Western Australia, Crawley 6009, Western Australia, Oceans Institute, University of Western Australia, Crawley 6009, Western Australia and
| | - Renae Hovey
- School of Plant Biology, University of Western Australia, Crawley 6009, Western Australia, Oceans Institute, University of Western Australia, Crawley 6009, Western Australia and
| | - Janet M Anthony
- School of Plant Biology, University of Western Australia, Crawley 6009, Western Australia, Kings Park and Botanic Gardens, West Perth 6005, Western Australia
| | - Kingsley W Dixon
- School of Plant Biology, University of Western Australia, Crawley 6009, Western Australia, Kings Park and Botanic Gardens, West Perth 6005, Western Australia, Environment and Agriculture, Curtin University, Bentley 6102, Western Australia
| | - Gary A Kendrick
- School of Plant Biology, University of Western Australia, Crawley 6009, Western Australia, Oceans Institute, University of Western Australia, Crawley 6009, Western Australia and
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Furman BT, Peterson BJ. Sexual Recruitment in Zostera marina: Progress toward a Predictive Model. PLoS One 2015; 10:e0138206. [PMID: 26368792 PMCID: PMC4569585 DOI: 10.1371/journal.pone.0138206] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/27/2015] [Indexed: 11/18/2022] Open
Abstract
Ecophysiological stress and physical disturbance are capable of structuring meadows through a combination of direct biomass removal and recruitment limitation; however, predicting these effects at landscape scales has rarely been successful. To model environmental influence on sexual recruitment in perennial Zostera marina, we selected a sub-tidal, light-replete study site with seasonal extremes in temperature and wave energy. During an 8-year observation period, areal coverage increased from 4.8 to 42.7%. Gains were stepwise in pattern, attributable to annual recruitment of patches followed by centrifugal growth and coalescence. Recruitment varied from 13 to 4,894 patches per year. Using a multiple linear regression approach, we examined the association between patch appearance and relative wave energy, atmospheric condition and water temperature. Two models were developed, one appropriate for the dispersal of naked seeds, and another for rafted flowers. Results indicated that both modes of sexual recruitment varied as functions of wind, temperature, rainfall and wave energy, with a regime shift in wind-wave energy corresponding to periods of rapid colonization within our site. Temporal correlations between sexual recruitment and time-lagged climatic summaries highlighted floral induction, seed bank and small patch development as periods of vulnerability. Given global losses in seagrass coverage, regions of recovery and re-colonization will become increasingly important. Lacking landscape-scale process models for seagrass recruitment, temporally explicit statistical approaches presented here could be used to forecast colonization trajectories and to provide managers with real-time estimates of future meadow performance; i.e., when to expect a good year in terms of seagrass expansion. To facilitate use as forecasting tools, we did not use statistical composites or normalized variables as our predictors. This study, therefore, represents a first step toward linking remotely acquired environmental data to sexual recruitment, an important measure of seagrass performance that translates directly into landscape-scale coverage change.
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Affiliation(s)
- Bradley T Furman
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York, United States of America
| | - Bradley J Peterson
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York, United States of America
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Ardehed A, Johansson D, Schagerström E, Kautsky L, Johannesson K, Pereyra RT. Complex spatial clonal structure in the macroalgae Fucus radicans with both sexual and asexual recruitment. Ecol Evol 2015; 5:4233-45. [PMID: 26664675 PMCID: PMC4667831 DOI: 10.1002/ece3.1629] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 07/03/2015] [Accepted: 07/08/2015] [Indexed: 11/19/2022] Open
Abstract
In dioecious species with both sexual and asexual reproduction, the spatial distribution of individual clones affects the potential for sexual reproduction and local adaptation. The seaweed Fucus radicans, endemic to the Baltic Sea, has separate sexes, but new attached thalli may also form asexually. We mapped the spatial distribution of clones (multilocus genotypes, MLGs) over macrogeographic (>500 km) and microgeographic (<100 m) scales in the Baltic Sea to assess the relationship between clonal spatial structure, sexual recruitment, and the potential for natural selection. Sexual recruitment was predominant in some areas, while in others asexual recruitment dominated. Where clones of both sexes were locally intermingled, sexual recruitment was nevertheless low. In some highly clonal populations, the sex ratio was strongly skewed due to dominance of one or a few clones of the same sex. The two largest clones (one female and one male) were distributed over 100–550 km of coast and accompanied by small and local MLGs formed by somatic mutations and differing by 1–2 mutations from the large clones. Rare sexual events, occasional long‐distance migration, and somatic mutations contribute new genotypic variation potentially available to natural selection. However, dominance of a few very large (and presumably old) clones over extensive spatial and temporal scales suggested that either these have superior traits or natural selection has only been marginally involved in the structuring of genotypes.
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Affiliation(s)
- Angelica Ardehed
- Department of Biology and Environmental Sciences University of Gothenburg Box 463, SE 405 30 Gothenburg Sweden
| | - Daniel Johansson
- Department of Biology and Environmental Sciences University of Gothenburg Box 463, SE 405 30 Gothenburg Sweden
| | - Ellen Schagerström
- Department of Ecology, Environment and Plant Sciences Stockholm University SE 106 91 Stockholm Sweden
| | - Lena Kautsky
- Department of Ecology, Environment and Plant Sciences Stockholm University SE 106 91 Stockholm Sweden
| | - Kerstin Johannesson
- Department of Marine Sciences-Tjärnö University of Gothenburg SE 452 96 Strömstad Sweden
| | - Ricardo T Pereyra
- Department of Marine Sciences-Tjärnö University of Gothenburg SE 452 96 Strömstad Sweden
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O father where art thou? Paternity analyses in a natural population of the haploid-diploid seaweed Chondrus crispus. Heredity (Edinb) 2014; 114:185-94. [PMID: 25227258 DOI: 10.1038/hdy.2014.82] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 08/11/2014] [Accepted: 08/11/2014] [Indexed: 02/03/2023] Open
Abstract
The link between life history traits and mating systems in diploid organisms has been extensively addressed in the literature, whereas the degree of selfing and/or inbreeding in natural populations of haploid-diploid organisms, in which haploid gametophytes alternate with diploid sporophytes, has been rarely measured. Dioecy has often been used as a proxy for the mating system in these organisms. Yet, dioecy does not prevent the fusion of gametes from male and female gametophytes originating from the same sporophyte. This is likely a common occurrence when spores from the same parent are dispersed in clumps and recruit together. This pattern of clumped spore dispersal has been hypothesized to explain significant heterozygote deficiency in the dioecious haploid-diploid seaweed Chondrus crispus. Fronds and cystocarps (structures in which zygotes are mitotically amplified) were sampled in two 25 m(2) plots located within a high and a low intertidal zone and genotyped at 5 polymorphic microsatellite loci in order to explore the mating system directly using paternity analyses. Multiple males sired cystocarps on each female, but only one of the 423 paternal genotypes corresponded to a field-sampled gametophyte. Nevertheless, larger kinship coefficients were detected between males siring cystocarps on the same female in comparison with males in the entire population, confirming restricted spermatial and clumped spore dispersal. Such dispersal mechanisms may be a mode of reproductive assurance due to nonmotile gametes associated with putatively reduced effects of inbreeding depression because of the free-living haploid stage in C. crispus.
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Sinclair EA, Gecan I, Krauss SL, Kendrick GA. Against the odds: complete outcrossing in a monoecious clonal seagrass Posidonia australis (Posidoniaceae). ANNALS OF BOTANY 2014; 113:1185-96. [PMID: 24812250 PMCID: PMC4030814 DOI: 10.1093/aob/mcu048] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 02/21/2014] [Indexed: 05/22/2023]
Abstract
BACKGROUND AND AIMS Seagrasses are marine, flowering plants with a hydrophilous pollination strategy. In these plants, successful mating requires dispersal of filamentous pollen grains through the water column to receptive stigmas. Approximately 40 % of seagrass species are monoecious, and therefore little pollen movement is required if inbreeding is tolerated. Outcrossing in these species is further impacted by clonality, which is variable, but can be extensive in large, dense meadows. Despite this, little is known about the interaction between clonal structure, genetic diversity and mating systems in hydrophilous taxa. METHODS Polymorphic microsatellite DNA markers were used to characterize genetic diversity, clonal structure, mating system and realized pollen dispersal in two meadows of the temperate, monoecious seagrass, Posidonia australis, in Cockburn Sound, Western Australia. KEY RESULTS Within the two sampled meadows, genetic diversity was moderate among the maternal shoots (R = 0·45 and 0·64) and extremely high in the embryos (R = 0·93-0·97). Both meadows exhibited a highly clumping (or phalanx) structure among clones, with spatial autocorrelation analysis showing significant genetic structure among shoots and embryos up to 10-15 m. Outcrossing rates were not significantly different from one. Pollen dispersal distances inferred from paternity assignment averaged 30·8 and 26·8 m, which was larger than the mean clone size (12·8 and 13·8 m). CONCLUSIONS These results suggest highly effective movement of pollen in the water column. Despite strong clonal structure and moderate genetic diversity within meadows, hydrophilous pollination is an effective vector for completely outcrossed offspring. The different localized water conditions at each site (highly exposed conditions vs. weak directional flow) appear to have little influence on the success and pattern of successful pollination in the two meadows.
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Affiliation(s)
- Elizabeth A Sinclair
- School of Plant Biology, University of Western Australia, Crawley, 6907 Western Australia Botanic Gardens & Parks Authority, Fraser Avenue, West Perth, 6005 Western Australia
| | - Ilena Gecan
- School of Plant Biology, University of Western Australia, Crawley, 6907 Western Australia
| | - Siegfried L Krauss
- School of Plant Biology, University of Western Australia, Crawley, 6907 Western Australia Botanic Gardens & Parks Authority, Fraser Avenue, West Perth, 6005 Western Australia
| | - Gary A Kendrick
- School of Plant Biology, University of Western Australia, Crawley, 6907 Western Australia Oceans Institute, University of Western Australia, Crawley, 6907 Western Australia
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18
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Vandepitte K, De Meyer T, Jacquemyn H, Roldán-Ruiz I, Honnay O. The impact of extensive clonal growth on fine-scale mating patterns: a full paternity analysis of a lily-of-the-valley population (Convallaria majalis). ANNALS OF BOTANY 2013; 111:623-8. [PMID: 23439847 PMCID: PMC3605957 DOI: 10.1093/aob/mct024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 01/03/2013] [Indexed: 05/26/2023]
Abstract
BACKGROUND AND AIMS The combination of clonality and a mating system promoting outcrossing is considered advantageous because outcrossing avoids the fitness costs of selfing within clones (geitonogamy) while clonality assures local persistence and increases floral display. The spatial spread of genetically identical plants (ramets) may, however, also decrease paternal diversity (the number of sires fertilizing a given dam) and fertility, particularly towards the centre of large clumped clones. This study aimed to quantify the impact of extensive clonal growth on fine-scale paternity patterns in a population of the allogamous Convallaria majalis. METHODS A full analysis of paternity was performed by genotyping all flowering individuals and all viable seeds produced during a single season using AFLP. Mating patterns were examined and the spatial position of ramets was related to the extent of multiple paternity, fruiting success and seed production. KEY RESULTS The overall outcrossing rate was high (91 %) and pollen flow into the population was considerable (27 %). Despite extensive clonal growth, multiple paternity was relatively common (the fraction of siblings sharing the same father was 0·53 within ramets). The diversity of offspring collected from reproductive ramets surrounded by genetically identical inflorescences was as high as among offspring collected from ramets surrounded by distinct genets. There was no significant relationship between the similarity of the pollen load received by two ramets and the distance between them. Neither the distance of ramets with respect to distinct genets nor the distance to the genet centre significantly affected fruiting success or seed production. CONCLUSIONS Random mating and considerable pollen inflow most probably implied that pollen dispersal distances were sufficiently high to mitigate local mate scarcity despite extensive clonal spread. The data provide no evidence for the intrusion of clonal growth on fine-scale plant mating patterns.
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Affiliation(s)
- Katrien Vandepitte
- Plant Conservation and Population Biology, Biology Department, University of Leuven, Kasteelpark Arenberg 31, B-3001 Heverlee, Belgium
| | - Tim De Meyer
- Laboratory for Bioinformatics and Computational Genomics, Mathematical Modelling, Statistics & Bioinformatics Department, Ghent University, Coupure Links 653, 9000 Ghent. Belgium
| | - Hans Jacquemyn
- Plant Conservation and Population Biology, Biology Department, University of Leuven, Kasteelpark Arenberg 31, B-3001 Heverlee, Belgium
| | - Isabel Roldán-Ruiz
- Plant Sciences Unit – Growth and Development, Institute for Agricultural and Fisheries Research ILVO, Caritasstraat 21, B-9090 Melle, Belgium
| | - Olivier Honnay
- Plant Conservation and Population Biology, Biology Department, University of Leuven, Kasteelpark Arenberg 31, B-3001 Heverlee, Belgium
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Lobelle D, Kenyon EJ, Cook KJ, Bull JC. Local competition and metapopulation processes drive long-term seagrass-epiphyte population dynamics. PLoS One 2013; 8:e57072. [PMID: 23437313 PMCID: PMC3578831 DOI: 10.1371/journal.pone.0057072] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 01/17/2013] [Indexed: 11/28/2022] Open
Abstract
It is well known that ecological processes such as population regulation and natural enemy interactions potentially occur over a range of spatial scales, and there is a substantial body of literature developing theoretical understanding of the interplay between these processes. However, there are comparatively few studies quantifying the long-term effects of spatial scaling in natural ecosystems. A key challenge is that trophic complexity in real-world biological communities quickly obscures the signal from a focal process. Seagrass meadows provide an excellent opportunity in this respect: in many instances, seagrasses effectively form extensive natural monocultures, in which hypotheses about endogenous dynamics can be formulated and tested. We present amongst the longest unbroken, spatially explict time series of seagrass abundance published to date. Data include annual measures of shoot density, total above-ground abundance, and associated epiphyte cover from five Zostera marina meadows distributed around the Isles of Scilly, UK, from 1996 to 2011. We explore empirical patterns at the local and metapopulation scale using standard time series analysis and develop a simple population dynamic model, testing the hypothesis that both local and metapopulation scale feedback processes are important. We find little evidence of an interaction between scales in seagrass dynamics but that both scales contribute approximately equally to observed local epiphyte abundance. By quantifying the long-term dynamics of seagrass-epiphyte interactions we show how measures of density and extent are both important in establishing baseline information relevant to predicting responses to environmental change and developing management plans. We hope that this study complements existing mechanistic studies of physiology, genetics and productivity in seagrass, whilst highlighting the potential of seagrass as a model ecosystem. More generally, this study provides a rare opportunity to test some of the predictions of ecological theory in a natural ecosystem of global conservation and economic value.
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Affiliation(s)
- Delphine Lobelle
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Emma J. Kenyon
- College of Medical and Dental Sciences, University of Birmingham, Birmingham, Alabama, United Kingdom
| | | | - James C. Bull
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
- * E-mail:
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Kendrick GA, Waycott M, Carruthers TJB, Cambridge ML, Hovey R, Krauss SL, Lavery PS, Les DH, Lowe RJ, Vidal OMI, Ooi JLS, Orth RJ, Rivers DO, Ruiz-Montoya L, Sinclair EA, Statton J, van Dijk JK, Verduin JJ. The Central Role of Dispersal in the Maintenance and Persistence of Seagrass Populations. Bioscience 2012. [DOI: 10.1525/bio.2012.62.1.10] [Citation(s) in RCA: 216] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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