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Mennicken S, Paula CCPD, Vogt-Schilb H, Jersáková J. Diversity of Mycorrhizal Fungi in Temperate Orchid Species: Comparison of Culture-Dependent and Culture-Independent Methods. J Fungi (Basel) 2024; 10:92. [PMID: 38392764 PMCID: PMC10890429 DOI: 10.3390/jof10020092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 01/14/2024] [Accepted: 01/17/2024] [Indexed: 02/24/2024] Open
Abstract
Many orchid species are endangered due to anthropogenic pressures such as habitat destruction and overharvesting, meanwhile, all orchids rely on orchid mycorrhizal fungi (OMF) for seed germination and seedling growth. Therefore, a better understanding of this intimate association is crucial for orchid conservation. Isolation and identification of OMF remain challenging as many fungi are unculturable. In our study, we tested the efficiency of both culture-dependent and culture-independent methods to describe OMF diversity in multiple temperate orchids and assessed any phylogenetic patterns in cultivability. The culture-dependent method involved the cultivation and identification of single pelotons (intracellular hyphal coils), while the culture-independent method used next-generation sequencing (NGS) to identify root-associated fungal communities. We found that most orchid species were associated with multiple fungi, and the orchid host had a greater impact than locality on the variability in fungal communities. The culture-independent method revealed greater fungal diversity than the culture-dependent one, but despite the lower detection, the isolated fungal strains were the most abundant OMF in adult roots. Additionally, the abundance of NGS reads of cultured OTUs was correlated with the extent of mycorrhizal root colonization in orchid plants. Finally, this limited-scale study tentatively suggests that the cultivability character of OMF may be randomly distributed along the phylogenetic trees of the rhizoctonian families.
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Affiliation(s)
- Sophie Mennicken
- Department of Ecosystem Biology, Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czech Republic
| | - Caio César Pires de Paula
- Department of Ecosystem Biology, Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czech Republic
- Institute of Hydrobiology, Biology Centre CAS, 37005 České Budějovice, Czech Republic
| | - Hélène Vogt-Schilb
- Department of Ecosystem Biology, Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czech Republic
- Centre d'Écologie Fonctionnelle et Évolutive (CEFE), Centre National de la Recherche Scientifique (CNRS), Université de Montpellier, École Pratique des Hautes Études (EPHE), Institut de Recherche pour le Développement (IRD), 1919 Route de Mende, 34293 Montpellier, France
| | - Jana Jersáková
- Department of Ecosystem Biology, Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czech Republic
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Kolanowska M. Loss of fungal symbionts and changes in pollinator availability caused by climate change will affect the distribution and survival chances of myco-heterotrophic orchid species. Sci Rep 2023; 13:6848. [PMID: 37100884 PMCID: PMC10133392 DOI: 10.1038/s41598-023-33856-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 04/20/2023] [Indexed: 04/28/2023] Open
Abstract
The first comprehensive species distribution models for orchid, its fungal symbionts and pollinator are presented. To evaluate impact of global warming on these organisms three different projections and four various climate change scenarios were analysed. The niche modelling was based on presence-only records of Limodorum abortivum, two species of Russula and three insects pollinating orchid (Anthophora affinis, Bombus terrestris, Rhodanthidium septemdentatum). Two sets of orchid predictions were examined-the first one included only climatic data and the second one was based on climate data and data on future distribution of orchid fungal symbionts. Overall, a poleward range shift is predicted to occur as a result of climate change and apparently global warming will be favorable for L. abortivum and its potential geographical range will expand. However, due to the negative effect of global warming on fungal symbionts of L. abortivum, the actual extension of the suitable niches of the orchid will be much limited. Considering future possibility of cross-pollination, the availability of A. affinis for L. abortivum will decrease and this bee will be available in the worst case scenarios only for 21% of orchid populations. On the other hand, the overlap of orchid and the buff-tailed bumblebee will increase and as much as 86.5% of plant populations will be located within B. terrestris potential range. Also the availability of R. septemdentatum will be higher than currently observed in almost all analysed climate change projections. This study showed the importance of inclusion of ecological factors in species distribution models as the climate data itself are not enough to estimate the future distribution of plant species. Moreover, the availability of pollen vectors which is crucial for long-term survival of orchid populations should be analysed in context of climate changes.
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Affiliation(s)
- Marta Kolanowska
- Department of Geobotany and Plant Ecology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237, Lodz, Poland.
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Arifin AR, Phillips RD, Linde CC. Strong phylogenetic congruence between Tulasnella fungi and their associated Drakaeinae orchids. J Evol Biol 2023; 36:221-237. [PMID: 36309962 PMCID: PMC10091943 DOI: 10.1111/jeb.14107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 09/09/2022] [Accepted: 09/12/2022] [Indexed: 01/11/2023]
Abstract
The study of congruency between phylogenies of interacting species can provide a powerful approach for understanding the evolutionary history of symbiotic associations. Orchid mycorrhizal fungi can survive independently of orchids making cospeciation unlikely, leading us to predict that any congruence would arise from host-switches to closely related fungal species. The Australasian orchid subtribe Drakaeinae is an iconic group of sexually deceptive orchids that consists of approximately 66 species. In this study, we investigated the evolutionary relationships between representatives of all six Drakaeinae orchid genera (39 species) and their mycorrhizal fungi. We used an exome capture dataset to generate the first well-resolved phylogeny of the Drakaeinae genera. A total of 10 closely related Tulasnella Operational Taxonomic Units (OTUs) and previously described species were associated with the Drakaeinae orchids. Three of them were shared among orchid genera, with each genus associating with 1-6 Tulasnella lineages. Cophylogenetic analyses show Drakaeinae orchids and their Tulasnella associates exhibit significant congruence (p < 0.001) in the topology of their phylogenetic trees. An event-based method also revealed significant congruence in Drakaeinae-Tulasnella relationships, with duplications (35), losses (25), and failure to diverge (9) the most frequent events, with minimal evidence for cospeciation (1) and host-switches (2). The high number of duplications suggests that the orchids speciate independently from the fungi, and the fungal species association of the ancestral orchid species is typically maintained in the daughter species. For the Drakaeinae-Tulasnella interaction, a pattern of phylogenetic niche conservatism rather than coevolution likely explains the observed phylogenetic congruency in orchid and fungal phylogenies. Given that many orchid genera are characterized by sharing of fungal species between closely related orchid species, we predict that these findings may apply to a wide range of orchid lineages.
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Affiliation(s)
- Arild R Arifin
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia.,Department of Plant Pathology, Washington State University Tree Fruit Research and Extension Center, Wenatchee, Washington, USA
| | - Ryan D Phillips
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia.,Department of Ecology, Environment & Evolution, La Trobe University, Bundoora, Victoria, Australia.,Department of Biodiversity, Conservation and Attractions, Kings Park Science, Perth, Western Australia, Australia.,Royal Botanic Gardens Victoria, Victoria, Australia
| | - Celeste C Linde
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
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Kitahara M, Nagamune K, Kinoshita A, Yugeta C, Ohara N, Shimazaki A, Yamashita Y, Yukawa T, Endo N, Ogura-Tsujita Y. <i>In-vitro</i> symbiotic germination of seeds of five mycoheterotrophic <i>Gastrodia</i> orchids with <i>Mycena</i> and <i>Marasmiaceae</i> fungi. MYCOSCIENCE 2022; 63:88-95. [PMID: 37089632 PMCID: PMC10042302 DOI: 10.47371/mycosci.2022.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 03/27/2022] [Accepted: 04/01/2022] [Indexed: 11/16/2022]
Abstract
We performed in-vitro germination tests on seeds from five Gastrodia orchids (G. confusa, G. elata var. elata, G. elata var. pallens, G. nipponica, and G. pubilabiata) using one Marasmiaceae and two Mycena isolates. Mycena sp. 1 promoted germination of all five Gastrodia orchids, with root and/or tuber formation observed in G. confusa, G. nipponica, and G. pubilabiata. No additional growth was observed in the other two orchids. Mycena sp. 2 induced G. confusa, G. elata var. elata, and G. nipponica germination, whereas Marasmiaceae sp. 1 induced G. nipponica and G. pubilabiata germination. Phylogenetic analyses indicated that the two Mycena isolates represent distinct lineages within the Mycenaceae. Mycena sp. 1 and Marasmiaceae sp. 1 are closely related to Mycena abramsii and Marasmiellus rhizomorphogenus, respectively. Our results imply that Mycena and marasmioid fungi play important roles in early development in Gastrodia species, and that Mycena fungi in particular may be common mycobionts of Gastrodia species. Root and/or tuber development was observed with four plant-fungus combinations, implying that these associations persist throughout the life cycle, whereas G. elata var. elata may require different associates over time. Our findings will contribute to elucidating the mycorrhizal associations of mycoheterotrophic orchids throughout their life cycle.
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Affiliation(s)
| | - Kosuke Nagamune
- Graduate School of Sustainability Science, Tottori University
| | - Akihiko Kinoshita
- Kyusyu Research Center, Forestry and Forest Products Research Institute
| | | | | | | | - Yumi Yamashita
- Faculty of Symbiotic Systems Science, Fukushima University
| | - Tomohisa Yukawa
- Tsukuba Botanical Garden, National Museum of Nature and Science
| | - Naoki Endo
- Fungus/Mushroom Resource and Research Center, Faculty of Agriculture, Tottori University
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Bersweden L, Viruel J, Schatz B, Harland J, Gargiulo R, Cowan RS, Calevo J, Juan A, Clarkson JJ, Leitch AR, Fay MF. Microsatellites and petal morphology reveal new patterns of admixture in Orchis hybrid zones. Am J Bot 2021; 108:1388-1404. [PMID: 34418070 DOI: 10.1002/ajb2.1710] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 02/20/2021] [Accepted: 02/23/2021] [Indexed: 05/23/2023]
Abstract
PREMISE The genetic structure of hybrid zones provides insight into the potential for gene flow to occur between plant taxa. Four closely related European orchid species (Orchis anthropophora, O. militaris, O. purpurea, and O. simia) hybridize when they co-occur. We aimed to characterize patterns of hybridization in O. militaris-O. purpurea, O. purpurea-O. simia, and O. anthropophora-O. simia hybrid zones using molecular and morphological data. METHODS We used 11 newly isolated nuclear microsatellites to genotype 695 individuals collected from seven hybrid zones and six allopatric parental populations in France. Geometric morphometric analysis was conducted using 15 labellum landmarks to capture the main aspects of petal shape. RESULTS Backcrossing was asymmetric toward O. militaris in multiple O. militaris-O. purpurea hybrid zones. Hybrids in O. purpurea-O. simia and O. anthropophora-O. simia hybrid zones were largely limited to F1 and F2 generations, but further admixture had occurred. These patterns were reflected in labellum geometric morphometric data, which correlated strongly with nuclear microsatellite data in all three species combinations. CONCLUSIONS The coexistence of parental and admixed individuals in these Orchis hybrid zones implies they are likely to be tension zones being maintained by a balance between gene flow into the hybrid zone and selection acting against admixed individuals. The pattern of admixture in the three species combinations suggests intrinsic selection acting on the hybrids is weaker in more closely related taxa.
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Affiliation(s)
- Leif Bersweden
- Jodrell Laboratory, Royal Botanic Gardens, Kew TW9 3DS, UK
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Juan Viruel
- Jodrell Laboratory, Royal Botanic Gardens, Kew TW9 3DS, UK
| | - Bertrand Schatz
- Centre for Ecology and Evolution, University of Montpellier, Montpellier 34090, France
| | - Joanna Harland
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | | | - Robyn S Cowan
- Jodrell Laboratory, Royal Botanic Gardens, Kew TW9 3DS, UK
| | - Jacopo Calevo
- Department of Life Sciences and Systems Biology, University of Turin, Turin 10125, Italy
| | - Ana Juan
- Department of Environmental Sciences & Natural Resources, University of Alicante, San Vicente, Alicante 03690, Spain
| | | | - Andrew R Leitch
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Michael F Fay
- Jodrell Laboratory, Royal Botanic Gardens, Kew TW9 3DS, UK
- School of Plant Biology, University of Western Australia, Crawley, WA 6009, Australia
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McCormick M, Burnett R, Whigham D. Protocorm-Supporting Fungi Are Retained in Roots of Mature Tipularia discolor Orchids as Mycorrhizal Fungal Diversity Increases. Plants (Basel) 2021; 10:1251. [PMID: 34202964 DOI: 10.3390/plants10061251] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 06/17/2021] [Accepted: 06/17/2021] [Indexed: 11/20/2022]
Abstract
Mycorrhizal fungi are critical to understanding the distribution patterns of many plants, but they are especially important for orchids. Some orchids may change the mycorrhizal fungi they use through their lives, either in response to changes in abiotic or biotic conditions, or as a result of ontogenetic changes that alter the orchid’s need for fungal nutrition. The temperate terrestrial orchid Tipularia discolor germinates only on decomposing wood, but often persists well after the wood has completely decomposed and has been incorporated into the soil. We used PCR and Sanger sequencing to ask: (1) Do mature T. discolor retain protocorm fungi or are protocorm and adult mycorrhizal fungi mutually exclusive? (2) Are protocorm fungi limited to areas with decomposing wood? (3) Does the abundance of protocorm fungi in the substrate differ between decomposing wood and bare soil? We found that T. discolor retained protocorm fungi into maturity, regardless of whether they were growing in persistent decomposing wood or soil. Protocorm fungi were not restricted to decomposing wood but were more common and abundant in it. We conclude that the mycorrhizal fungi associated with T. discolor change during the ontogeny of individuals. These results highlight the importance of assessing protocorm fungi, in addition to mycorrhizal fungi associating with adult orchids, to understand the conditions needed for orchid germination, growth, and reproduction.
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Li T, Wu S, Yang W, Selosse MA, Gao J. How Mycorrhizal Associations Influence Orchid Distribution and Population Dynamics. Front Plant Sci 2021; 12:647114. [PMID: 34025695 PMCID: PMC8138319 DOI: 10.3389/fpls.2021.647114] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 04/13/2021] [Indexed: 05/04/2023]
Abstract
Orchid distribution and population dynamics are influenced by a variety of ecological factors and the formation of holobionts, which play key roles in colonization and ecological community construction. Seed germination, seedling establishment, reproduction, and survival of orchid species are strongly dependent on orchid mycorrhizal fungi (OMF), with mycorrhizal cheating increasingly observed in photosynthetic orchids. Therefore, changes in the composition and abundance of OMF can have profound effects on orchid distribution and fitness. Network analysis is an important tool for the study of interactions between plants, microbes, and the environment, because of the insights that it can provide into the interactions and coexistence patterns among species. Here, we provide a comprehensive overview, systematically describing the current research status of the effects of OMF on orchid distribution and dynamics, phylogenetic signals in orchid-OMF interactions, and OMF networks. We argue that orchid-OMF associations exhibit complementary and specific effects that are highly adapted to their environment. Such specificity of associations may affect the niche breadth of orchid species and act as a stabilizing force in plant-microbe coevolution. We postulate that network analysis is required to elucidate the functions of fungal partners beyond their effects on germination and growth. Such studies may lend insight into the microbial ecology of orchids and provide a scientific basis for the protection of orchids under natural conditions in an efficient and cost-effective manner.
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Affiliation(s)
- Taiqiang Li
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Shimao Wu
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Wenke Yang
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Marc-André Selosse
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
- Institut de Systématique, Évolution, Biodiversité, UMR 7205, CNRS, MNHN, UPMC, EPHE, Muséum National d’Histoire Naturelle, Sorbonne Universités, Paris, France
- Department of Plant Taxonomy and Nature Conservation, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Jiangyun Gao
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
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Li T, Yang W, Wu S, Selosse MA, Gao J. Progress and Prospects of Mycorrhizal Fungal Diversity in Orchids. Front Plant Sci 2021; 12:646325. [PMID: 34025694 PMCID: PMC8138444 DOI: 10.3389/fpls.2021.646325] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 04/12/2021] [Indexed: 05/03/2023]
Abstract
Orchids form mycorrhizal symbioses with fungi in natural habitats that affect their seed germination, protocorm growth, and adult nutrition. An increasing number of studies indicates how orchids gain mineral nutrients and sometime even organic compounds from interactions with orchid mycorrhizal fungi (OMF). Thus, OMF exhibit a high diversity and play a key role in the life cycle of orchids. In recent years, the high-throughput molecular identification of fungi has broadly extended our understanding of OMF diversity, revealing it to be a dynamic outcome co-regulated by environmental filtering, dispersal restrictions, spatiotemporal scales, biogeographic history, as well as the distribution, selection, and phylogenetic spectrum width of host orchids. Most of the results show congruent emerging patterns. Although it is still difficult to extend them to all orchid species or geographical areas, to a certain extent they follow the "everything is everywhere, but the environment selects" rule. This review provides an extensive understanding of the diversity and ecological dynamics of orchid-fungal association. Moreover, it promotes the conservation of resources and the regeneration of rare or endangered orchids. We provide a comprehensive overview, systematically describing six fields of research on orchid-fungal diversity: the research methods of orchid-fungal interactions, the primer selection in high-throughput sequencing, the fungal diversity and specificity in orchids, the difference and adaptability of OMF in different habitats, the comparison of OMF in orchid roots and soil, and the spatiotemporal variation patterns of OMF. Further, we highlight certain shortcomings of current research methodologies and propose perspectives for future studies. This review emphasizes the need for more information on the four main ecological processes: dispersal, selection, ecological drift, and diversification, as well as their interactions, in the study of orchid-fungal interactions and OMF community structure.
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Affiliation(s)
- Taiqiang Li
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Wenke Yang
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Shimao Wu
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Marc-André Selosse
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
- Institut de Systématique, Évolution, Biodiversité, UMR 7205, CNRS, MNHN, UPMC, EPHE, Muséum National d’Histoire Naturelle, Sorbonne Universités, Paris, France
- Department of Plant Taxonomy and Nature Conservation, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Jiangyun Gao
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
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Shao SC, Luo Y, Jacquemyn H. Co-Cultures of Mycorrhizal Fungi Do Not Increase Germination and Seedling Development in the Epiphytic Orchid Dendrobium nobile. Front Plant Sci 2020; 11:571426. [PMID: 33193505 PMCID: PMC7644947 DOI: 10.3389/fpls.2020.571426] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 09/29/2020] [Indexed: 05/27/2023]
Abstract
Orchids are highly dependent on mycorrhizal fungi for seed germination and subsequent growth to a seedling as they provide essential carbon, water, and mineral nutrients to developing seeds. Although there is mounting evidence that orchid seeds are often colonized by multiple fungi simultaneously, most in vitro germination experiments focus on mycorrhizal monocultures and little is known about how mycorrhizal assemblages affect seed germination and growth of seedlings. In this study, we compared the effects of mycorrhizal monocultures and co-cultures on seed germination and seedling growth of the epiphytic orchid Dendrobium nobile. In situ baiting was used to isolate mycorrhizal fungi from protocorms for germination experiments. Germination experiments were conducted under two light regimes for 90 days. In total, five fungal strains were isolated from protocorms of D. nobile, indicating that the species was not highly specific to its fungal partners. Four strains (JC-01, JC-02, JC-04, and JC-05) belonged to the Serendipitaceae and one (JC-03) to the Tulasnellaceae. In vitro germination experiments showed that germination percentages were higher under light-dark conditions than under complete dark conditions, supporting previous findings that light facilitates germination in epiphytic orchids. While all strains were able to induce protocorm formation and growth into the seedling stage, large differences between fungal strains were observed. Co-cultures did not result in significantly higher seed germination percentages and seedling development than monocultures. Taken together, these results demonstrate that effects of fungal assemblages are not predictable from those of component species, and that more work is needed to better understand the role of fungal assemblages determining seed germination and subsequent growth under natural conditions.
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Affiliation(s)
- Shi-Cheng Shao
- Gardening and Horticulture Department, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, China
| | - Yan Luo
- Gardening and Horticulture Department, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, China
| | - Hans Jacquemyn
- Department of Biology, Plant Conservation and Population Biology, KU Leuven, Leuven, Belgium
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Evans A, Janssens S, Jacquemyn H. Impact of Climate Change on the Distribution of Four Closely Related Orchis (Orchidaceae) Species. Diversity 2020; 12:312. [DOI: 10.3390/d12080312] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Long-term monitoring programs and population demographic models have shown that the population dynamics of orchids are to a large extent dependent on prevailing weather conditions, suggesting that the changes in climatic conditions can have far reaching effects on the population dynamics and hence the distribution of orchids. Although a better understanding of the effects of climate change on the distribution of plants has become increasingly important during the final years, only a few studies have investigated the effects of changing temperature and precipitation on the distribution of orchids. In this study, we investigated the impact of climate change on the distribution of four terrestrial orchid species (Orchis anthropophora, Orchis militaris, Orchis purpurea and Orchis simia). Using bioclimatic data for current and future climate scenarios, habitat suitability, range shifts and the impact of different abiotic factors on the range of each species were modelled using Maxent. The results revealed an increase in suitable habitat area for O. anthropophora, O. purpurea and O. simia under each RCP (Representative Concentration Pathway) scenario, while a decrease was observed for O. militaris. Furthermore, all four of the orchids showed a shift to higher latitudes under the three RCPs leading to a significant range extension under mild climate change. Under severe climate change, a significant decline in the distribution area at the warm edge of their distributions was observed. Overall, these results show that mild climate change may be beneficial for the studied orchid species and lead to range expansion. However, continued warming may yet prove detrimental, as all species also showed pronounced declines at lower latitudes when temperature increases were larger than 4 °C.
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Pecoraro L, Wang X, Venturella G, Gao W, Wen T, Gafforov Y, Gupta VK. Molecular evidence supports simultaneous association of the achlorophyllous orchid Chamaegastrodia inverta with ectomycorrhizal Ceratobasidiaceae and Russulaceae. BMC Microbiol 2020; 20:236. [PMID: 32746782 PMCID: PMC7397628 DOI: 10.1186/s12866-020-01906-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 07/14/2020] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Achlorophyllous orchids are mycoheterotrophic plants, which lack photosynthetic ability and associate with fungi to acquire carbon from different environmental sources. In tropical latitudes, achlorophyllous forest orchids show a preference to establish mycorrhizal relationships with saprotrophic fungi. However, a few of them have been recently found to associate with ectomycorrhizal fungi and there is still much to be learned about the identity of fungi associated with tropical orchids. The present study focused on mycorrhizal diversity in the achlorophyllous orchid C. inverta, an endangered species, which is endemic to southern China. The aim of this work was to identify the main mycorrhizal partners of C. inverta in different plant life stages, by means of morphological and molecular methods. RESULTS Microscopy showed that the roots of analysed C. inverta samples were extensively colonized by fungal hyphae forming pelotons in root cortical cells. Fungal ITS regions were amplified by polymerase chain reaction, from DNA extracted from fungal mycelia isolated from orchid root samples, as well as from total root DNA. Molecular sequencing and phylogenetic analyses showed that the investigated orchid primarily associated with ectomycorrhizal fungi belonging to a narrow clade within the family Ceratobasidiaceae, which was previously detected in a few fully mycoheterotrophic orchids and was also found to show ectomycorrhizal capability on trees and shrubs. Russulaceae fungal symbionts, showing high similarity with members of the ectomycorrhizal genus Russula, were also identified from the roots of C. inverta, at young seedling stage. Ascomycetous fungi including Chaetomium, Diaporthe, Leptodontidium, and Phomopsis genera, and zygomycetes in the genus Mortierella were obtained from orchid root isolated strains with unclear functional role. CONCLUSIONS This study represents the first assessment of root fungal diversity in the rare, cryptic and narrowly distributed Chinese orchid C. inverta. Our results provide new insights on the spectrum of orchid-fungus symbiosis suggesting an unprecedented mixed association between the studied achlorophyllous forest orchid and ectomycorrhizal fungi belonging to Ceratobasidiaceae and Russulaceae. Ceratobasidioid fungi as dominant associates in the roots of C. inverta represent a new record of the rare association between the identified fungal group and fully mycoheterotrophic orchids in nature.
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Affiliation(s)
- Lorenzo Pecoraro
- School of Pharmaceutical Science and Technology, Health Sciences Platform, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, China.
| | - Xiao Wang
- School of Pharmaceutical Science and Technology, Health Sciences Platform, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, China
| | - Giuseppe Venturella
- Department of Agricultural, Food and Forest Sciences, University of Palermo, Palermo, Italy
| | - Wenyuan Gao
- School of Pharmaceutical Science and Technology, Health Sciences Platform, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, China
| | - Tingchi Wen
- The Engineering Research Center of Southwest Bio-Pharmaceutical Resources, Ministry of Education, Guizhou University, Guiyang, China
| | - Yusufjon Gafforov
- Laboratory of Mycology, Institute of Botany, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan
| | - Vijai Kumar Gupta
- AgroBioSciences and Chemical & Biochemical Sciences Department, University Mohammed VI Polytechnic, Hay Moulay Rachid, Ben Guerir, Morocco
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Meng Y, Fan X, Zhou L, Shao S, Liu Q, Selosse M, Gao J. Symbiotic fungi undergo a taxonomic and functional bottleneck during orchid seeds germination: a case study on Dendrobium moniliforme. Symbiosis 2019; 79:205-12. [DOI: 10.1007/s13199-019-00647-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Meng YY, Zhang WL, Selosse MA, Gao JY. Are fungi from adult orchid roots the best symbionts at germination? A case study. Mycorrhiza 2019; 29:541-547. [PMID: 31312918 DOI: 10.1007/s00572-019-00907-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 07/09/2019] [Indexed: 05/03/2023]
Abstract
We studied mycobionts from advanced seedlings and adult mycorrhizal roots of the terrestrial orchid Arundina graminifolia. Fungi were isolated, identified by ITS sequencing, and tested for their impact on seed germination, protocorm formation, and development of advanced seedlings (emergence of first leaf) in vitro. Among the six fungal species isolated, four were not standard orchid mycorrhizal fungi (Fusarium solani, Cylindrocarpon sp., Acremonium sp., and Phlebiopsis flavidoalba) and did not support germination beyond imbibition and greening of the seeds during a span of 35 days. Over the same time, one Tulasnella species isolated from adult mycorrhiza allowed protocorm formation but not further development. However, another Tulasnella species isolated from advanced seedlings facilitated development to the advanced seedling stage. Our results support (i) the inability of occasional orchid root colonizers to support late seed germination, and (ii) the growing literature showing that fungal associates can change over orchid development. Functionally, we show that mycorrhizal taxa isolated from advanced seedlings can be more efficient than those from adults in supporting germination in some species, leading to recommendations for ex situ orchid conservation.
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Affiliation(s)
- Yuan-Yuan Meng
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, Yunnan, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wen-Liu Zhang
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, 650500, Yunnan, China
| | - Marc-André Selosse
- Département Systématique et Evolution, UMR 7205 ISYEB, Muséum national d'Histoire naturelle, CP50, 45 rue Buffon, 75005, Paris, France
- Faculty of Biology, University of Gdansk, ul. Wita Stwosza 59, 80-308, Gdansk, Poland
| | - Jiang-Yun Gao
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, 650500, Yunnan, China.
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Abstract
BACKGROUND Gastrodia elata is a widely distributed achlorophyllous orchid and is highly valued as both medicine and food. Gastrodia elata produces dust-like seeds and relies on mycorrhizal fungi for its germination and growth. In its life cycle, G. elata is considered to switch from a specific single-fungus relationship (Mycena) to another single-fungus relationship (Armillaria). However, no studies have investigated the changes in the plant-fungus relationship during the growth of G. elata in the wild. In this study, high-throughput sequencing was used to characterize the fungal community of tubers in different growth phases as well as the soils surrounding G. elata. RESULTS The predominant fungi were Basidiomycota (60.44%) and Ascomycota (26.40%), which exhibited changes in abundance and diversity with the growth phases of G. elata. Diverse basidiomycetes in protocorms (phase P) were Hyphodontia, Sistotrema, Tricholoma, Mingxiaea, Russula, and Mycena, but the community changed from a large proportion of Resinicium bicolor (40%) in rice-like tubers (phase M) to an unidentified Agaricales operational taxonomic unit 1(OTU1,98.45%) in propagation vegetation tubers (phase B). The soil fungi primarily included Simocybe, Psathyrella, Conocybe, and Subulicystidium. Three Mycena OTUs obtained in this study were differentially distributed among the growth phases of G. elata, accounting for less than 1.0% of the total reads, and were phylogenetically close to Mycena epipterygia and M. alexandri. CONCLUSIONS Our data indicated that G. elata interacts with a broad range of fungi beyond the Mycena genus. These fungi changed with the growth phases of G. elata. In addition, these data suggested that the development of the fungal community during the growth of G. elata was more complex than previously assumed and that at least two different fungi could be involved in development before the arrival of Armillaria.
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Affiliation(s)
- Lin Chen
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, 650091, China
- School of Ecology and Environmental Science, Yunnan University, Kunming, 650091, China
- School of Life Sciences, Yunnan University, Kunming, 650091, China
| | - Yu-Chuan Wang
- Gastrodia Tuber Research Institute of Zhaotong, Zhaotong, 657000, Yunnan Province, China
| | - Li-Yuan Qin
- School of Life Sciences, Yunnan University, Kunming, 650091, China
| | - Hai-Yan He
- Gastrodia Tuber Research Institute of Zhaotong, Zhaotong, 657000, Yunnan Province, China
| | - Xian-Lun Yu
- Gastrodia Tuber Research Institute of Zhaotong, Zhaotong, 657000, Yunnan Province, China
| | - Ming-Zhi Yang
- School of Life Sciences, Yunnan University, Kunming, 650091, China.
| | - Han-Bo Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, 650091, China.
- School of Ecology and Environmental Science, Yunnan University, Kunming, 650091, China.
- School of Life Sciences, Yunnan University, Kunming, 650091, China.
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Tao Z, Ren Z, Bernhardt P, Liang H, Li H, Zhao Y, Wang H, Li D. Does reproductive isolation reflect the segregation of color forms in Spiranthes sinensis (Pers.) Ames complex (Orchidaceae) in the Chinese Himalayas? Ecol Evol 2018; 8:5455-5469. [PMID: 29938065 PMCID: PMC6010815 DOI: 10.1002/ece3.4067] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 03/09/2018] [Accepted: 03/12/2018] [Indexed: 01/16/2023] Open
Abstract
Isolation between species, or taxa sharing a common lineage, depends primarily on the relative strengths of various reproductive barriers. Previous studies on reproductive isolation between orchids emphasized mechanical and ethological barriers in flowers of species showing food and/or sexual mimicry. In this study, we investigated and quantified a series of prepollination and postpollination barriers between pink and white forms of Spiranthes sinensis sl, a nectar-secreting complex. We generated ML trees based on trnS-G and matK to explore phylogenetic relationships in this species complex. Spiranthes sinensis sl segregated from some other congeners, but the white form constituted a distinct clade in relation to the pink form. The white form secreted 2-Phenylethanol as it is a single-scent compound and was pollinated almost exclusively by native, large-bodied Apis cerana and Bombus species (Apidae). Apis cerana showed a high floral constancy to this form. The scentless, pink form was pollinated primarily by smaller bees in the genera Ceratina (Apidae), and members of the family Halictidae, with infrequent visits by A. cerana and Bombus species. Fruit set and the production of large embryos following interform pollination treatments were significantly lower compared to intraform pollination results for the white form. Our results suggested that pollinator isolation, based on color and scent cues, may result in greater floral constancy in white populations when both forms are sympatric as two different, guilds of pollinators forage selectively preventing or reducing prospective gene flow. Postpollination barriers appear weaker than prepollination barriers but they also play a role in interform isolation, especially in the white form. Our findings suggest that floral color forms in S. sinensis do not represent an unbalanced polymorphism. Interpretations of the evolutionary status of these forms are discussed.
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Affiliation(s)
- Zhi‐Bin Tao
- Key Laboratory for Plant Diversity and Biogeography of East AsiaKunming Institute of BotanyChinese Academy of SciencesKunmingChina
- Kunming College of Life SciencesUniversity of Chinese Academy of SciencesKunmingChina
| | - Zong‐Xin Ren
- Key Laboratory for Plant Diversity and Biogeography of East AsiaKunming Institute of BotanyChinese Academy of SciencesKunmingChina
| | | | - Huan Liang
- Key Laboratory for Plant Diversity and Biogeography of East AsiaKunming Institute of BotanyChinese Academy of SciencesKunmingChina
- Kunming College of Life SciencesUniversity of Chinese Academy of SciencesKunmingChina
| | - Hai‐Dong Li
- Key Laboratory for Plant Diversity and Biogeography of East AsiaKunming Institute of BotanyChinese Academy of SciencesKunmingChina
| | - Yan‐Hui Zhao
- Key Laboratory for Plant Diversity and Biogeography of East AsiaKunming Institute of BotanyChinese Academy of SciencesKunmingChina
| | - Hong Wang
- Key Laboratory for Plant Diversity and Biogeography of East AsiaKunming Institute of BotanyChinese Academy of SciencesKunmingChina
| | - De‐Zhu Li
- Germplasm Bank of Wild SpeciesKunming Institute of BotanyChinese Academy of SciencesKunmingChina
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Pecoraro L, Caruso T, Cai L, Gupta VK, Liu ZJ. Fungal networks and orchid distribution: new insights from above- and below-ground analyses of fungal communities. IMA Fungus 2018; 9:1-11. [PMID: 30018868 PMCID: PMC6048571 DOI: 10.5598/imafungus.2018.09.01.01] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 01/27/2018] [Indexed: 01/27/2023] Open
Abstract
Orchids are critically dependent on fungi for seedling establishment and growth, so the distribution and diversity of orchids might depend on the associated fungal communities. We characterised the communities associated with eight orchid species in three Mediterranean protected areas, using a combination of above-ground analyses of sporophores and below-ground molecular analyses of orchid root samples. In three years of sporophore collection in 25 plots around flowering orchid plants, 268 macrofungal species belonging to 84 genera were observed. Statistical analyses indicated a correlation between macrofungal diversity and orchid community variation, regardless of the effect of environmental and spatial factors characterizing the investigated orchid sites. Fungal ITS-DNA PCR amplification, cloning, and sequencing revealed Rhizoctonia-like fungi belonging to Ceratobasidiaceae (26 %), Tulasnellaceae (22.5 %), and Sebacinaceae (3.5 %), as well as other basidiomycetes and ascomycetes, in the roots of 99 orchid plants. Mycorrhizal specificity was low but co-occurring orchid species showed preferences for different partners. The diverse macrofungal communities found in the sites may contribute to orchid community variation without colonizing the orchid roots. Molecular analyses revealed a segregation of associated fungi, which may contribute to Mediterranean orchid coexistence in nature.
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Affiliation(s)
- Lorenzo Pecoraro
- Shenzhen Key Laboratory for Orchid Conservation and Utilization, The National Orchid Conservation Center of China and The Orchid Conservation and Research Center of Shenzhen, 518114 Shenzhen, China
- Center for Biotechnology & BioMedicine and Division of Life & Health Sciences, Graduate School at Shenzhen, Tsinghua University, 518055 Shenzhen, China
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, 100101 Beijing, China
| | - Tancredi Caruso
- School of Biological Sciences, Queen's University of Belfast, BT9 7BL Belfast, Northern Ireland
| | - Lei Cai
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, 100101 Beijing, China
| | - Vijai Kumar Gupta
- Department of Chemistry and Biotechnology, ERA Chair of Green Chemistry, School of Science, Tallinn University of Technology, 12618 Tallinn, Estonia
| | - Zhong-Jian Liu
- Shenzhen Key Laboratory for Orchid Conservation and Utilization, The National Orchid Conservation Center of China and The Orchid Conservation and Research Center of Shenzhen, 518114 Shenzhen, China
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18
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Schweiger JM, Bidartondo MI, Gebauer G. Stable isotope signatures of underground seedlings reveal the organic matter gained by adult orchids from mycorrhizal fungi. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13042] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Julienne M.‐I. Schweiger
- Laboratory of Isotope BiogeochemistryBayreuth Center of Ecology and Environmental Research (BayCEER)University of Bayreuth Bayreuth Germany
| | - Martin I. Bidartondo
- Department of Life SciencesImperial College London London UK
- Royal Botanic GardensKew Richmond UK
| | - Gerhard Gebauer
- Laboratory of Isotope BiogeochemistryBayreuth Center of Ecology and Environmental Research (BayCEER)University of Bayreuth Bayreuth Germany
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19
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Esposito F, Vereecken NJ, Gammella M, Rinaldi R, Laurent P, Tyteca D. Characterization of sympatric Platanthera bifolia and Platanthera chlorantha (Orchidaceae) populations with intermediate plants. PeerJ 2018; 6:e4256. [PMID: 29379684 PMCID: PMC5787349 DOI: 10.7717/peerj.4256] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 12/20/2017] [Indexed: 12/25/2022] Open
Abstract
Platanthera bifolia and P. chlorantha are terrestrial and rewarding orchids with a wide Eurasian distribution. Although genetically closely related, they exhibit significant morphological, phenological and ecological differences that maintain reproductive isolation between the species. However, where both species co-occur, individuals with intermediate phenotypic traits, often considered as hybrids, are frequently observed. Here, we combined neutral genetic markers (AFLPs), morphometrics and floral scent analysis (GC-MS) to investigate two mixed Platanthera populations where morphologically intermediate plants were found. Self-pollination experiments revealed a low level of autogamy and artificial crossings combined with assessments of fruit set and seed viability, showed compatibility between the two species. The results of the genetic analyses showed that morphologically intermediate plants had similar genetic patterns as the P. bifolia group. These results are corroborated also by floral scent analyses, which confirmed a strong similarity in floral scent composition between intermediate morphotypes and P. bifolia. Therefore, this study provided a much more detailed picture of the genetic structure of a sympatric zone between two closely allied species and supports the hypothesis that intermediate morphotypes in sympatry could reflect an adaptive evolution in response to local pollinator-mediated selection.
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Affiliation(s)
- Fabiana Esposito
- Earth and Life Institute-Biodiversity Research Centre, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Nicolas J Vereecken
- Agroecology Lab, Brussels Bioengineering School, Université libre de Bruxelles (ULB), Brussels, Belgium
| | | | - Rosita Rinaldi
- Department of Biology, University of Naples Federico II, Napoli, Italy
| | - Pascal Laurent
- Unit of General Chemistry, Université Libre de Bruxelles, Brussels, Belgium
| | - Daniel Tyteca
- Earth and Life Institute-Biodiversity Research Centre, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
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20
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Jacquemyn H, Kort HD, Broeck AV, Brys R. Immigrant and extrinsic hybrid seed inviability contribute to reproductive isolation between forest and dune ecotypes of Epipactis helleborine
(Orchidaceae). OIKOS 2017. [DOI: 10.1111/oik.04329] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Hans Jacquemyn
- Dept of Biology; Plant Conservation and Population Biology; BE-3001 Leuven Belgium
| | - Hanne De Kort
- Dept of Biology; Plant Conservation and Population Biology; BE-3001 Leuven Belgium
- Station d'Ecologie Théorique et Expérimentale du CNRS, Centre National de la Recherche Scientifique; Moulis France
| | | | - Rein Brys
- Research Inst. for Forest and Nature; Geraardsbergen Belgium
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21
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Gervasi DDL, Selosse MA, Sauve M, Francke W, Vereecken NJ, Cozzolino S, Schiestl FP. Floral scent and species divergence in a pair of sexually deceptive orchids. Ecol Evol 2017; 7:6023-6034. [PMID: 28808562 PMCID: PMC5551101 DOI: 10.1002/ece3.3147] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 04/14/2017] [Accepted: 05/17/2017] [Indexed: 01/08/2023] Open
Abstract
Speciation is typically accompanied by the formation of isolation barriers between lineages. Commonly, reproductive barriers are separated into pre‐ and post‐zygotic mechanisms that can evolve with different speed. In this study, we measured the strength of different reproductive barriers in two closely related, sympatric orchids of the Ophrys insectifera group, namely Ophrys insectifera and Ophrys aymoninii to infer possible mechanisms of speciation. We quantified pre‐ and post‐pollination barriers through observation of pollen flow, by performing artificial inter‐ and intraspecific crosses and analyzing scent bouquets. Additionally, we investigated differences in mycorrhizal fungi as a potential extrinsic factor of post‐zygotic isolation. Our results show that floral isolation mediated by the attraction of different pollinators acts apparently as the sole reproductive barrier between the two orchid species, with later‐acting intrinsic barriers seemingly absent. Also, the two orchids share most of their fungal mycorrhizal partners in sympatry, suggesting little or no importance of mycorrhizal symbiosis in reproductive isolation. Key traits underlying floral isolation were two alkenes and wax ester, present predominantly in the floral scent of O. aymoninii. These compounds, when applied to flowers of O. insectifera, triggered attraction and a copulation attempt of the bee pollinator of O. aymoninii and thus led to the (partial) breakdown of floral isolation. Based on our results, we suggest that adaptation to different pollinators, mediated by floral scent, underlies species isolation in this plant group. Pollinator switches may be promoted by low pollination success of individuals in dense patches of plants, an assumption that we also confirmed in our study.
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Affiliation(s)
- Daniel D L Gervasi
- Department of Systematic and Evolutionary Botany University of Zürich Zürich Switzerland
| | - Marc-Andre Selosse
- Institut de Systématique, Évolution, Biodiversité (ISYEB)UMR 7205 CNRS MNHN UPMC EPHE Muséum national d'Histoire naturelle Sorbonne Universités Paris France.,Department of Plant Taxonomy and Nature Conservation University of Gdansk Gdańsk Poland
| | - Mathieu Sauve
- Institut de Systématique, Évolution, Biodiversité (ISYEB)UMR 7205 CNRS MNHN UPMC EPHE Muséum national d'Histoire naturelle Sorbonne Universités Paris France
| | - Wittko Francke
- Institute of Organic Chemistry University of Hamburg Hamburg Germany
| | - Nicolas J Vereecken
- Agroecology and Pollination Group Landscape Ecology and Plant Production Systems Université libre de Bruxelles (ULB) Brussels Belgium
| | | | - Florian P Schiestl
- Department of Systematic and Evolutionary Botany University of Zürich Zürich Switzerland
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22
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Oja J, Vahtra J, Bahram M, Kohout P, Kull T, Rannap R, Kõljalg U, Tedersoo L. Local-scale spatial structure and community composition of orchid mycorrhizal fungi in semi-natural grasslands. Mycorrhiza 2017; 27:355-367. [PMID: 28039600 DOI: 10.1007/s00572-016-0755-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 11/30/2016] [Indexed: 05/20/2023]
Abstract
Orchid mycorrhizal (OrM) fungi play a crucial role in the ontogeny of orchids, yet little is known about how the structure of OrM fungal communities varies with space and environmental factors. Previous studies suggest that within orchid patches, the distance to adult orchids may affect the abundance of OrM fungi. Many orchid species grow in species-rich temperate semi-natural grasslands, the persistence of which depends on moderate physical disturbances, such as grazing and mowing. The aim of this study was to test whether the diversity, structure and composition of OrM fungal community are influenced by the orchid patches and management intensity in semi-natural grasslands. We detected putative OrM fungi from 0 to 32 m away from the patches of host orchid species (Orchis militaris and Platanthera chlorantha) in 21 semi-natural calcareous grasslands using pyrosequencing. In addition, we assessed different ecological conditions in semi-natural grasslands but primarily focused on the effect of grazing intensity on OrM fungal communities in soil. We found that investigated orchid species were mostly associated with Ceratobasidiaceae and Tulasnellaceae and, to a lesser extent, with Sebacinales. Of all the examined factors, the intensity of grazing explained the largest proportion of variation in OrM fungal as well as total fungal community composition in soil. Spatial analyses showed limited evidence for spatial clustering of OrM fungi and their dependence on host orchids. Our results indicate that habitat management can shape OrM fungal communities, and the spatial distribution of these fungi appears to be weakly structured outside the orchid patches.
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Affiliation(s)
- Jane Oja
- Institute of Ecology and Earth Sciences, University of Tartu, 14A Ravila, 50411, Tartu, Estonia.
| | - Johanna Vahtra
- Institute of Ecology and Earth Sciences, University of Tartu, 14A Ravila, 50411, Tartu, Estonia
| | - Mohammad Bahram
- Institute of Ecology and Earth Sciences, University of Tartu, 14A Ravila, 50411, Tartu, Estonia
- Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, SE 75236, Uppsala, Sweden
| | - Petr Kohout
- Institute of Ecology and Earth Sciences, University of Tartu, 14A Ravila, 50411, Tartu, Estonia
- Institute of Botany, Academy of Sciences of the Czech Republic, 252 43, Průhonice, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, CZ-128 01, Prague 2, Czech Republic
| | - Tiiu Kull
- Institute of Agricultural and Environmental Sciences Estonian, University of Life Sciences, 5 Kreutzwaldi, 51014, Tartu, Estonia
| | - Riinu Rannap
- Institute of Ecology and Earth Sciences, University of Tartu, 46 Vanemuise, 51014, Tartu, Estonia
| | - Urmas Kõljalg
- Institute of Ecology and Earth Sciences, University of Tartu, 14A Ravila, 50411, Tartu, Estonia
| | - Leho Tedersoo
- Institute of Ecology and Earth Sciences, University of Tartu, 14A Ravila, 50411, Tartu, Estonia
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Cevallos S, Sánchez-Rodríguez A, Decock C, Declerck S, Suárez JP. Are there keystone mycorrhizal fungi associated to tropical epiphytic orchids? Mycorrhiza 2017; 27:225-232. [PMID: 27882467 DOI: 10.1007/s00572-016-0746-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 11/15/2016] [Indexed: 05/20/2023]
Abstract
In epiphytic orchids, distinctive groups of fungi are involved in the symbiotic association. However, little is known about the factors that determine the mycorrhizal community structure. Here, we analyzed the orchid mycorrhizal fungi communities associated with three sympatric Cymbidieae epiphytic tropical orchids (Cyrtochilum flexuosum, Cyrtochilum myanthum, and Maxillaria calantha) at two sites located within the mountain rainforest of southern Ecuador. To characterize these communities at each orchid population, the ITS2 region was analyzed by Illumina MiSeq technology. Fifty-five mycorrhizal fungi operational taxonomic units (OTUs) putatively attributed to members of Serendipitaceae, Ceratobasidiaceae and Tulasnellaceae were identified. Significant differences in mycorrhizal communities were detected between the three sympatric orchid species as well as among sites/populations. Interestingly, some mycorrhizal OTUs overlapped among orchid populations. Our results suggested that populations of studied epiphytic orchids have site-adjusted mycorrhizal communities structured around keystone fungal species. Interaction with multiple mycorrhizal fungi could favor orchid site occurrence and co-existence among several orchid species.
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Affiliation(s)
- Stefania Cevallos
- Earth and Life Institute, Applied Microbiology, Mycology, Université catholique de Louvain, Croix du Sud 2, box L7.05.06, B-1348, Louvain-la-Neuve, Belgium
- Departamento de Ciencias Biológicas, Universidad Técnica Particular de Loja, 11-01-608, Loja, Ecuador
| | - Aminael Sánchez-Rodríguez
- Departamento de Ciencias Biológicas, Universidad Técnica Particular de Loja, 11-01-608, Loja, Ecuador
| | - Cony Decock
- Earth and Life Institute, Applied Microbiology, Mycology, Université catholique de Louvain, Mycothèque de l'Université catholique de Louvain (MUCL1), Croix du Sud 2, box L7.05.06, 1348, Louvain-la-Neuve, Belgium
| | - Stéphane Declerck
- Earth and Life Institute, Applied Microbiology, Mycology, Université catholique de Louvain, Croix du Sud 2, box L7.05.06, B-1348, Louvain-la-Neuve, Belgium
| | - Juan Pablo Suárez
- Departamento de Ciencias Biológicas, Universidad Técnica Particular de Loja, 11-01-608, Loja, Ecuador.
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Waud M, Brys R, Van Landuyt W, Lievens B, Jacquemyn H. Mycorrhizal specificity does not limit the distribution of an endangered orchid species. Mol Ecol 2017; 26:1687-1701. [DOI: 10.1111/mec.14014] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/08/2016] [Accepted: 01/11/2017] [Indexed: 01/26/2023]
Affiliation(s)
- Michael Waud
- Department of Biology, Plant Conservation and Population Biology; KU Leuven; B-3001 Leuven Belgium
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM); Department of Microbial and Molecular Systems (M2S); KU Leuven; Campus De Nayer B-2860 Sint-Katelijne-Waver Belgium
| | - Rein Brys
- Research Institute for Forest and Nature; B-1070 Brussels Belgium
| | | | - Bart Lievens
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM); Department of Microbial and Molecular Systems (M2S); KU Leuven; Campus De Nayer B-2860 Sint-Katelijne-Waver Belgium
| | - Hans Jacquemyn
- Department of Biology, Plant Conservation and Population Biology; KU Leuven; B-3001 Leuven Belgium
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Rasmussen HN, Dixon KW, Jersáková J, Těšitelová T. Germination and seedling establishment in orchids: a complex of requirements. Ann Bot 2015; 116:391-402. [PMID: 26271118 PMCID: PMC4549959 DOI: 10.1093/aob/mcv087] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 01/08/2015] [Accepted: 04/30/2015] [Indexed: 05/03/2023]
Abstract
BACKGROUND Seedling recruitment is essential to the sustainability of any plant population. Due to the minute nature of seeds and early-stage seedlings, orchid germination in situ was for a long time practically impossible to observe, creating an obstacle towards understanding seedling site requirements and fluctuations in orchid populations. The introduction of seed packet techniques for sowing and retrieval in natural sites has brought with it important insights, but many aspects of orchid seed and germination biology remain largely unexplored. KEY CONSIDERATIONS The germination niche for orchids is extremely complex, because it is defined by requirements not only for seed lodging and germination, but also for presence of a fungal host and its substrate. A mycobiont that the seedling can parasitize is considered an essential element, and a great diversity of Basidiomycota and Ascomycota have now been identified for their role in orchid seed germination, with fungi identifiable as imperfect Rhizoctonia species predominating. Specificity patterns vary from orchid species employing a single fungal lineage to species associating individually with a limited selection of distantly related fungi. A suitable organic carbon source for the mycobiont constitutes another key requirement. Orchid germination also relies on factors that generally influence the success of plant seeds, both abiotic, such as light/shade, moisture, substrate chemistry and texture, and biotic, such as competitors and antagonists. Complexity is furthermore increased when these factors influence seeds/seedling, fungi and fungal substrate differentially. CONCLUSIONS A better understanding of germination and seedling establishment is needed for conservation of orchid populations. Due to the obligate association with a mycobiont, the germination niches in orchid species are extremely complex and varied. Microsites suitable for germination can be small and transient, and direct observation is difficult. An experimental approach using several levels of environmental manipulation/control is recommended.
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Affiliation(s)
- Hanne N Rasmussen
- Geosciences and Nature Management, University of Copenhagen, Frederiksberg C, 1958, Denmark,
| | - Kingsley W Dixon
- School of Plant Biology, The University of Western Australia and Kings Park and Botanic Garden, WA 6005, Australia and
| | - Jana Jersáková
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Tamara Těšitelová
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
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Oja J, Kohout P, Tedersoo L, Kull T, Kõljalg U. Temporal patterns of orchid mycorrhizal fungi in meadows and forests as revealed by 454 pyrosequencing. New Phytol 2015; 205:1608-1618. [PMID: 25546739 DOI: 10.1111/nph.13223] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 11/13/2014] [Indexed: 05/20/2023]
Abstract
Orchid mycorrhizal (OrM) symbionts play a key role in the growth of orchids, but the temporal variation and habitat partitioning of these fungi in roots and soil remain unclear. Temporal changes in root and rhizosphere fungal communities of Cypripedium calceolus, Neottia ovata and Orchis militaris were studied in meadow and forest habitats over the vegetation period by using 454 pyrosequencing of the full internal transcribed spacer (ITS) region. The community of typical OrM symbionts differed by plant species and habitats. The root fungal community of N. ovata changed significantly in time, but this was not observed in C. calceolus and O. militaris. The rhizosphere community included a low proportion of OrM symbionts that exhibited a slight temporal turnover in meadow habitats but not in forests. Habitat differences in OrM and all fungal associates are largely attributable to the greater proportion of ectomycorrhizal fungi in forests. Temporal changes in OrM fungal communities in roots of certain species indicate selection of suitable fungal species by plants. It remains to be elucidated whether these shifts depend on functional differences inside roots, seasonality, climate or succession.
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Affiliation(s)
- Jane Oja
- Institute of Ecology and Earth Sciences, University of Tartu, 14A Ravila, 50411, Tartu, Estonia
| | - Petr Kohout
- Institute of Ecology and Earth Sciences, University of Tartu, 14A Ravila, 50411, Tartu, Estonia
- Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43, Průhonice, Czech Republic
| | - Leho Tedersoo
- Institute of Ecology and Earth Sciences, University of Tartu, 14A Ravila, 50411, Tartu, Estonia
| | - Tiiu Kull
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, 5 Kreutzwaldi, 51014, Tartu, Estonia
| | - Urmas Kõljalg
- Institute of Ecology and Earth Sciences, University of Tartu, 14A Ravila, 50411, Tartu, Estonia
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Pecoraro L, Girlanda M, Liu Z, Huang L, Perotto S. Molecular analysis of fungi associated with the Mediterranean orchid Ophrys bertolonii Mor. ANN MICROBIOL 2015; 65:2001-7. [DOI: 10.1007/s13213-015-1038-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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De Hert K, Honnay O, Jacquemyn H. Germination failure is not a critical stage of reproductive isolation between three congeneric orchid species. Am J Bot 2012; 99:1884-1890. [PMID: 23132617 DOI: 10.3732/ajb.1200381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
PREMISE OF THE STUDY In food-deceptive orchid species, postmating reproductive barriers (fruit set and embryo mortality) have been shown to be more important for reproductive isolation than premating barriers (pollinator isolation). However, currently there is very little knowledge about whether germination failure acts as a reproductive barrier in hybridizing orchid species. METHODS In this study, we investigated germination and protocorm development of pure and hybrid seeds of three species of the orchid genus Dactylorhiza. To test the hypothesis that germination failure contributed to total reproductive isolation, reproductive barriers based on germination were combined with already available data on early acting barriers (fruit set and embryo mortality) to calculate the relative and absolute contributions of these barriers to reproductive isolation. KEY RESULTS Protocorms were formed in all crosses, indicating that both hybrid and pure seeds were able to germinate and grow into protocorms. Also, the number of protocorms per seed packet was not significantly different between hybrid and pure seeds. High fruit set, high seed viability, and substantial seed germination resulted in very low reproductive isolation (average RI = 0.05). In two of six interspecific crosses, hybrids performed even better than the intraspecific crosses. CONCLUSIONS Very weak postmating reproductive barriers were observed between our study species and may explain the frequent occurrence of first-generation hybrids in mixed Dactylorhiza populations. Germination failure, which is regarded as one of the most important bottlenecks in the orchid life cycle, was not important for reproductive isolation.
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Affiliation(s)
- Koen De Hert
- Biology Department, Laboratory of Plant Conservation and Population Biology, University of Leuven, Kasteelpark Arenberg 31, B-3001 Heverlee, Belgium.
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De hert K, Jacquemyn H, Provoost S, Honnay O. Absence of Recruitment Limitation in Restored Dune Slacks Suggests That Manual Seed Introduction Can Be a Successful Practice for Restoring Orchid Populations. Restor Ecol 2012. [DOI: 10.1111/j.1526-100x.2012.00925.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Koen De hert
- Biology Department, Laboratory of Plant Conservation and Population Biology; University of Leuven; Kasteelpark Arenberg 31; B-3001; Heverlee; Belgium
| | - Hans Jacquemyn
- Biology Department, Laboratory of Plant Conservation and Population Biology; University of Leuven; Kasteelpark Arenberg 31; B-3001; Heverlee; Belgium
| | - Sam Provoost
- Research Institute for Nature and Forest (INBO); Kliniekstraat 25; B-1070; Brussels; Belgium
| | - Olivier Honnay
- Biology Department, Laboratory of Plant Conservation and Population Biology; University of Leuven; Kasteelpark Arenberg 31; B-3001; Heverlee; Belgium
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Abstract
AbstractWe have assessed the identities of fungi associated with Orchis tridentata, an endangered orchid species growing in open woodland and poor grassland of Central and Southern Europe. Fungal diversity in ten O. tridentata adult individuals collected in two protected areas of Central Italy was analysed by means of morphological and molecular methods. Sequencing of the cloned ITS fungal inserts corresponding to the dominant PCR products obtained from amplification of total root DNA with ITS1F and ITS4 primers revealed a variety of fungal species occurring in O. tridentata roots. Among them, members of the basidiomycete families Ceratobasidiaceae, Tulasnellaceae and Hymenogastraceae were recovered, together with ascomycetes belonging to Leptodontidium and Terfezia. The implications of these results in the understanding of O. tridentata biology and for the conservation of this threatened orchid species are discussed.
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Jacquemyn H, Brys R, Honnay O, Roldán-Ruiz I. Asymmetric gene introgression in two closely related Orchis species: evidence from morphometric and genetic analyses. BMC Evol Biol 2012; 12:178. [PMID: 22967086 DOI: 10.1186/1471-2148-12-178] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Accepted: 09/07/2012] [Indexed: 11/16/2022] Open
Abstract
Background In food-deceptive orchids of the genera Anacamptis, Neotinea and Orchis floral isolation has been shown to be weak, whereas late-acting reproductive barriers are mostly strong, often restricting hybridization to the F1 generation. Only in a few species hybridization extends beyond the F1 generation, giving rise to hybrid swarms. However, little is known about the abundance of later-generation hybrids and what factors drive their occurrence in hybrid populations. In this study, molecular analyses were combined with detailed morphological measurements in a hybrid population of two closely related Orchis species (Orchis militaris and O. purpurea) to investigate the hypothesis that the abundance of later-generation hybrids is driven by changes in floral characters after hybridization that exert selective pressures that in turn affect hybridization. Results Both the molecular and morphological data point to extensive genetic and morphological homogenization and asymmetric introgression. Estimating genomic clines from the multi-locus genotype data and testing for deviation from neutrality revealed that 30 out of 113 (27%) AFLP markers significantly deviated from neutral expectations. Plants with large floral displays or plant with flowers that resembled more O. purpurea had higher female fitness than plants with small floral displays or plants with flowers resembling more O. militaris, suggesting that directional selection may have contributed to the observed patterns of introgression. Conclusions These results indicate that in closely related orchid species hybridization and gene introgression may be partly driven by selection for floral traits of one of the parental types. However, because some pure individuals were still present in the studied population, the parental species appeared to be sufficiently isolated to survive the challenge of sympatry.
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Marques I, Aguilar JF, Martins-Loução MA, Feliner GN. Spatial–temporal patterns of flowering asynchrony and pollinator fidelity in hybridizing species of Narcissus. Evol Ecol 2012. [DOI: 10.1007/s10682-012-9554-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Jacquemyn H, Brys R, Honnay O, Roldán-Ruiz I, Lievens B, Wiegand T. Nonrandom spatial structuring of orchids in a hybrid zone of three Orchis species. New Phytol 2012; 193:454-464. [PMID: 21955096 DOI: 10.1111/j.1469-8137.2011.03913.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
• Nonrandom species-species associations may arise from a range of factors, including localized dispersal, intra- and interspecific interactions and heterogeneous environmental conditions. Because seed germination and establishment in orchids are critically dependent upon the availability of suitable mycorrhizal fungi, species-species associations in orchids may reflect associations with mycorrhizal fungi. • To test this hypothesis, we examined spatial association patterns, mycorrhizal associations and germination success in a hybrid zone containing three species of the genus Orchis (Orchis anthropophora, Orchis militaris and Orchis purpurea). • Hybridization occurred predominantly between O. purpurea and O. militaris. The spatial distribution patterns of most pure species and hybrids were independent from each other, except that of O. purpurea and its hybrids. The fungal community composition of established individuals differed significantly between pure species, but not between hybrids and O. purpurea. Seed germination experiments using pure seeds showed that the highest number of protocorms were found in regions where adult individuals were most abundant. In the case of hybrid seeds, germination was restricted to areas where the mother plant was most abundant. • Overall, these results suggest that the observed nonrandom spatial distribution of both pure and hybrid plants is dependent on the contingencies of the spatial distribution of suitable mycorrhizal fungi.
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Affiliation(s)
- Hans Jacquemyn
- Division of Plant Ecology and Systematics, Biology Department, KU Leuven, Heverlee, Belgium.
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Jacquemyn H, Merckx V, Brys R, Tyteca D, Cammue BPA, Honnay O, Lievens B. Analysis of network architecture reveals phylogenetic constraints on mycorrhizal specificity in the genus Orchis (Orchidaceae). New Phytol 2011; 192:518-28. [PMID: 21668874 DOI: 10.1111/j.1469-8137.2011.03796.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The specificity of orchids for their fungi can vary substantially, from highly specialist interactions to more generalist interactions, but little is known about the evolutionary history of the mycorrhizal specificity of orchids. Here, we used a network analysis approach to investigate orchid mycorrhizal associations in 16 species of the genus Orchis sampled across 11 different regions in Europe. We first examined in detail the structure of the network of associations and then tested for a phylogenetic signal in mycorrhizal specificity and identified the fungi with which the orchids associated. We found 20 different fungal lineages that associated with species of the genus Orchis, most of them being related to members of the Tulasnellaceae (84.33% of all identified associations) and a smaller proportion being related to members of the Ceratobasidiaceae (9.97%). Species associations formed a nested network that is built on asymmetric links among species. Evolution of mycorrhizal specificity in Orchis closely resembles a Brownian motion process, and the interaction between Orchis and Tulasnellaceae fungi is significantly influenced by the phylogenetic relationships between the Orchis species. Our results provide evidence of the presence of phylogenetic conservatism in mycorrhizal specificity in orchids and demonstrate that evolutionary processes may be an important factor in generating patterns of mycorrhizal associations.
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