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Leidinger L, Vedder D, Cabral JS. Temporal environmental variation may impose differential selection on both genomic and ecological traits. OIKOS 2021. [DOI: 10.1111/oik.08172] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Ludwig Leidinger
- Center for Computational and Theoretical Biology, Faculty of Biology, Univ. of Würzburg Würzburg Germany
| | - Daniel Vedder
- Center for Computational and Theoretical Biology, Faculty of Biology, Univ. of Würzburg Würzburg Germany
| | - Juliano Sarmento Cabral
- Center for Computational and Theoretical Biology, Faculty of Biology, Univ. of Würzburg Würzburg Germany
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2
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Hedrén M, Birkedal S, de Boer H, Ghorbani A, Gravendeel B, Hansson S, Svensson Å, Zarre S. Asymmetric contributions of seed and pollen to gene dispersal in the marsh orchid Dactylorhiza umbrosa in Asia Minor. Mol Ecol 2021; 30:1791-1805. [PMID: 33587812 DOI: 10.1111/mec.15848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 07/25/2020] [Accepted: 08/05/2020] [Indexed: 11/29/2022]
Abstract
Orchids differ from other plants in their extremely small and partly air-filled seeds that can be transported long distances by wind. Seed dispersal in orchids is expected to contribute strongly to overall gene flow, and orchids generally express low levels of genetic differentiation between populations and low pollen to seed flow ratios. However, studies in orchids distributed in northern Europe have often found a poor geographic structuring of genetic variation. Here, we studied geographic differentiation in the marsh orchid Dactylorhiza umbrosa, which is widely distributed in upland regions from Asia Minor to Central Asia. These areas were less affected by Pleistocene ice ages than northern Europe and the orchid should have been able to survive the last ice age in local refugia. In the plastid genome, which is dispersed by seeds, populations at close distance were clearly divergent, but the differentiation still increased with geographic distance, and a significant phylogeographic structure had developed. In the nuclear genome, which is dispersed by both seeds and pollen, populations showed an even stronger correlation between genetic and geographic distance, but average levels of differentiation were lower than in the plastid genome, and no phylogeographic structure was evident. Combining plastid and nuclear data, we found that the ratio of pollen to seed dispersal (mp/ms) decreases with physical distance. Comparison with orchids that grow in parts of Europe that were glaciated during the last ice suggests that a balanced structure of genetic diversity develops only slowly in many terrestrial orchids, despite efficient seed dispersal.
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Affiliation(s)
- Mikael Hedrén
- Department of Biology, University of Lund, Lund, Sweden
| | | | - Hugo de Boer
- Natural History Museum, University of Oslo, Oslo, Norway.,Department of Organismal Biology, Uppsala University, Uppsala, Sweden.,Endless Forms Group, Naturalis Biodiversity Center, Leiden, The Netherlands
| | | | - Barbara Gravendeel
- Endless Forms Group, Naturalis Biodiversity Center, Leiden, The Netherlands
| | | | - Åke Svensson
- Department of Dermatology, Malmö University Hospital SUS, Malmö, Sweden
| | - Shahin Zarre
- Department of Plant Sciences, School of Biology, College of Science, University of Tehran, Tehran, Iran
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Kotilínek M, Těšitelová T, Košnar J, Fibich P, Hemrová L, Koutecký P, Münzbergová Z, Jersáková J. Seed dispersal and realized gene flow of two forest orchids in a fragmented landscape. PLANT BIOLOGY (STUTTGART, GERMANY) 2020; 22:522-532. [PMID: 32056355 DOI: 10.1111/plb.13099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 02/01/2020] [Indexed: 06/10/2023]
Abstract
Species with vast production of dust-like windborne seeds, such as orchids, should not be limited by seed dispersal. This paradigm, however, does not fit recent studies showing that many sites suitable for orchids are unoccupied and most seeds land close to their maternal plant. To explore this issue, we studied seed dispersal and gene flow of two forest orchid species, Epipactis atrorubens and Cephalanthera rubra, growing in a fragmented landscape of forested limestone hills in southwest Bohemia, Czech Republic. We used a combination of seed trapping and plant genotyping methods (microsatellite DNA markers) to quantify short- and long-distance dispersal, respectively. In addition, seed production of both species was estimated. We found that most seeds landed very close to maternal plants (95% of captured seeds were within 7.2 m) in both species, and dispersal distance was influenced by forest type in E. atrorubens. In addition, C. rubra showed clonal reproduction (20% of plants were of clonal origin) and very low fruiting success (only 1.6% of plants were fruiting) in comparison with E. atrorubens (25.7%). Gene flow was frequent up to 2 km in C. rubra and up to 125 km in E. atrorubens, and we detected a relatively high dispersal rate among regions in both species. Although both species occupy similar habitats and have similar seed dispersal abilities, C. rubra is notably rarer in the study area. Considerably low fruiting success in this species likely limits its gene flow to longer distances and designates it more sensitive to habitat loss and fragmentation.
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Affiliation(s)
- M Kotilínek
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - T Těšitelová
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - J Košnar
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - P Fibich
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
- Institute of Botany, Czech Academy of Sciences, Průhonice, Czech Republic
| | - L Hemrová
- Institute of Botany, Czech Academy of Sciences, Průhonice, Czech Republic
| | - P Koutecký
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Z Münzbergová
- Institute of Botany, Czech Academy of Sciences, Průhonice, Czech Republic
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic
| | - J Jersáková
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
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Zhang Z, Gale SW, Li JH, Fischer GA, Ren MX, Song XQ. Pollen-mediated gene flow ensures connectivity among spatially discrete sub-populations of Phalaenopsis pulcherrima, a tropical food-deceptive orchid. BMC PLANT BIOLOGY 2019; 19:597. [PMID: 31888488 PMCID: PMC6937714 DOI: 10.1186/s12870-019-2179-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 11/29/2019] [Indexed: 05/20/2023]
Abstract
BACKGROUND Gene flow in plants via pollen and seeds is asymmetrical at different geographic scales. Orchid seeds are adapted to long-distance wind dispersal but pollinium transfer is often influenced by pollinator behavior. We combined field studies with an analysis of genetic diversity among 155 physically mapped adults and 1105 F1 seedlings to evaluate the relative contribution of pollen and seed dispersal to overall gene flow among three sub-populations of the food-deceptive orchid Phalaenopsis pulcherrima on Hainan Island, China. RESULTS Phalaenopsis pulcherrima is self-sterile and predominantly outcrossing, resulting in high population-level genetic diversity, but plants are clumped and exhibit fine-scale genetic structuring. Even so, we detected low differentiation among sub-populations, with polynomial regression analysis suggesting gene flow via seed to be more restricted than that via pollen. Paternity analysis confirmed capsules of P. pulcherrima to each be sired by a single pollen donor, probably in part facilitated by post-pollination stigma obfuscation, with a mean pollen flow distance of 272.7 m. Despite limited sampling, we detected no loss of genetic diversity from one generation to the next. CONCLUSIONS Outcrossing mediated by deceptive pollination and self-sterility promote high genetic diversity in P. pulcherrima. Long-range pollinia transfer ensures connectivity among sub-populations, offsetting the risk of genetic erosion at local scales.
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Affiliation(s)
- Zhe Zhang
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants (Hainan University), Ministry of Education, College of Forestry, Hainan University, Haikou, People's Republic of China
- Key Laboratory of Germplasm Resources of Tropical Special Ornamental Plants of Hainan Province, College of Forestry, Hainan University, Haikou, People's Republic of China
| | - Stephan W Gale
- Kadoorie Farm & Botanic Garden, Lam Kam Road, Tai Po, Hong Kong, People's Republic of China.
| | - Ji-Hong Li
- Kadoorie Farm & Botanic Garden, Lam Kam Road, Tai Po, Hong Kong, People's Republic of China
| | - Gunter A Fischer
- Kadoorie Farm & Botanic Garden, Lam Kam Road, Tai Po, Hong Kong, People's Republic of China
| | - Ming-Xun Ren
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants (Hainan University), Ministry of Education, College of Forestry, Hainan University, Haikou, People's Republic of China
- Center for Terrestrial Biodiversity of the South China Sea, Hainan University, Haikou, People's Republic of China
| | - Xi-Qiang Song
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants (Hainan University), Ministry of Education, College of Forestry, Hainan University, Haikou, People's Republic of China.
- Key Laboratory of Germplasm Resources of Tropical Special Ornamental Plants of Hainan Province, College of Forestry, Hainan University, Haikou, People's Republic of China.
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Torres E, Riofrío ML, Iriondo JM. Complex fine-scale spatial genetic structure in Epidendrum rhopalostele: an epiphytic orchid. Heredity (Edinb) 2019; 122:458-467. [PMID: 30185924 PMCID: PMC6460762 DOI: 10.1038/s41437-018-0139-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 06/06/2018] [Accepted: 08/05/2018] [Indexed: 11/08/2022] Open
Abstract
Orchid seeds are presumably dispersed by wind due to their very small size and thus can potentially travel long distances. However, the few related studies indicate that seeds fall close to their mother plants. Because seed dispersal and colonization patterns can have relevant consequences for long-term species persistence, we assessed the fine-scale genetic structure of the epiphytic orchid Epidendrum rhopalostele to provide insight into these patterns. All individuals in the studied population were georeferenced and genotyped with AFLP-markers. Genetic structure was evaluated at two levels (forest and tree) using three approaches: principal coordinates analysis, model-based clustering, and spatial autocorrelation analysis. Results showed two genetic groups, composed of individuals from almost every tree with orchids. Spatial autocorrelation analysis at the forest level found no significant genetic structure when all individuals were considered, but a pattern of genetic patches was revealed when the analysis was performed separately for each group. Genetic patches had an estimated diameter of 4 m and were composed of individuals from more than one tree. A weak genetic structure was detected at the tree level at distances less than 1.5 m. These results suggest that many seeds fall close to the mother plant and become established in the same host tree. Additionally, a sequential colonization process seems to be the predominant mode of expansion, whereby progeny from orchids in one tree colonize neighboring trees. Thus, the existence of two distinct genetic groups and the presence of genetic patches should be considered when seed sampling for ex situ conservation.
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Affiliation(s)
- Elena Torres
- Department of Biotechnology-Plant Biology, Universidad Politécnica de Madrid, Madrid, Spain.
| | - María-Lorena Riofrío
- Department of Biological Sciences, Universidad Técnica Particular de Loja, Loja, Ecuador
| | - José M Iriondo
- Area of Biodiversity and Conservation, Universidad Rey Juan Carlos, Móstoles, Spain
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Hedrén M, Olofsson SN, Paun O. Orchid colonization: multiple parallel dispersal events and mosaic genetic structure in Dactylorhiza majalis ssp. lapponica on the Baltic island of Gotland. ANNALS OF BOTANY 2018; 122:1019-1032. [PMID: 29955767 PMCID: PMC6266126 DOI: 10.1093/aob/mcy111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 05/29/2018] [Indexed: 06/08/2023]
Abstract
Background and Aims The island of Gotland in the Baltic Sea has had no contact with surrounding continental areas since the withdrawal of the Weichselian ice sheet at approx. 17 ka BP. Plants present on Gotland must have arrived by long-distance dispersal, so populations are expected to exhibit reduced levels of genetic diversity compared with populations on surrounding mainlands. However, orchids have very small seeds, which appear well adapted to long-distance dispersal, and they should therefore be less affected than other plant species by colonization bottlenecks. The aim of this study was to analyse the genetic structure of orchids colonizing isolated islands, using the marsh orchid Dactylorhiza majalis ssp. lapponica as a case study. Methods More than 500 samples from 27 populations were analysed for 15 plastid and eight nuclear marker loci. Population diversity and differentiation patterns were compared for nuclear and plastid marker systems and analysed in relation to geographical location. Key Results We found high genetic diversity but no clear geographical structure of genetic differentiation between populations on Gotland. However, the between-population differentiation in plastid and nuclear markers were correlated and the greatest diversity was found at sites at comparatively high elevations, which were the first to emerge above the water after the Ice Age. Conclusions The regional population on Gotland has been established by a minimum of four dispersal events from continental regions. Subsequent gene flow between sites has not yet homogenized the differentiation pattern originating from initial colonization. We conclude that long-distance seed dispersal in orchids has a strong impact on structuring genetic diversity during periods of expansion and colonization, but contributes less to gene flow between populations once a stable population structure has been achieved.
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Affiliation(s)
- Mikael Hedrén
- Department of Biology, University of Lund, Lund, Sweden
| | | | - Ovidiu Paun
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
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Dafni A, Vereecken NJ. Pollination biology from micro-morphological adaptations to community ecology of plant-pollinator interactions. PLANT BIOLOGY (STUTTGART, GERMANY) 2016; 18:3-8. [PMID: 26768999 DOI: 10.1111/plb.12411] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- A Dafni
- Department of Evolutionary and Environmental Biology, Institute of Evolution, Haifa University, Haifa, Israel.
| | - N J Vereecken
- Agroecology & Pollination Group, Landscape Ecology & Plant Production Systems, Interfaculty School of Bioengineering, Université Libre de Bruxelles (ULB), Boulevard du Triomphe CP 264/2, B-1050, Brussels, Belgium
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