1
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Pezzi PH, Wheeler LC, Freitas LB, Smith SD. Incomplete lineage sorting and hybridization underlie tree discordance in Petunia and related genera (Petunieae, Solanaceae). Mol Phylogenet Evol 2024; 198:108136. [PMID: 38909873 DOI: 10.1016/j.ympev.2024.108136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 06/06/2024] [Accepted: 06/17/2024] [Indexed: 06/25/2024]
Abstract
Despite the overarching history of species divergence, phylogenetic studies often reveal distinct topologies across regions of the genome. The sources of these gene tree discordances are variable, but incomplete lineage sorting (ILS) and hybridization are among those with the most biological importance. Petunia serves as a classic system for studying hybridization in the wild. While field studies suggest that hybridization is frequent, the extent of reticulation within Petunia and its closely related genera has never been examined from a phylogenetic perspective. In this study, we used transcriptomic data from 11 Petunia, 16 Calibrachoa, and 10 Fabiana species to illuminate the relationships between these species and investigate whether hybridization played a significant role in the diversification of the clade. We inferred that gene tree discordance within genera is linked to hybridization events along with high levels of ILS due to their rapid diversification. Moreover, network analyses estimated deeper hybridization events between Petunia and Calibrachoa, genera that have different chromosome numbers. Although these genera cannot hybridize at the present time, ancestral hybridization could have played a role in their parallel radiations, as they share the same habitat and life history.
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Affiliation(s)
- Pedro H Pezzi
- Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
| | - Lucas C Wheeler
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, USA
| | - Loreta B Freitas
- Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Stacey D Smith
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, USA
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2
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Leal JL, Milesi P, Hodková E, Zhou Q, James J, Eklund DM, Pyhäjärvi T, Salojärvi J, Lascoux M. Complex Polyploids: Origins, Genomic Composition, and Role of Introgressed Alleles. Syst Biol 2024; 73:392-418. [PMID: 38613229 PMCID: PMC11282369 DOI: 10.1093/sysbio/syae012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 12/18/2023] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
Introgression allows polyploid species to acquire new genomic content from diploid progenitors or from other unrelated diploid or polyploid lineages, contributing to genetic diversity and facilitating adaptive allele discovery. In some cases, high levels of introgression elicit the replacement of large numbers of alleles inherited from the polyploid's ancestral species, profoundly reshaping the polyploid's genomic composition. In such complex polyploids, it is often difficult to determine which taxa were the progenitor species and which taxa provided additional introgressive blocks through subsequent hybridization. Here, we use population-level genomic data to reconstruct the phylogenetic history of Betula pubescens (downy birch), a tetraploid species often assumed to be of allopolyploid origin and which is known to hybridize with at least four other birch species. This was achieved by modeling polyploidization and introgression events under the multispecies coalescent and then using an approximate Bayesian computation rejection algorithm to evaluate and compare competing polyploidization models. We provide evidence that B. pubescens is the outcome of an autoploid genome doubling event in the common ancestor of B. pendula and its extant sister species, B. platyphylla, that took place approximately 178,000-188,000 generations ago. Extensive hybridization with B. pendula, B. nana, and B. humilis followed in the aftermath of autopolyploidization, with the relative contribution of each of these species to the B. pubescens genome varying markedly across the species' range. Functional analysis of B. pubescens loci containing alleles introgressed from B. nana identified multiple genes involved in climate adaptation, while loci containing alleles derived from B. humilis revealed several genes involved in the regulation of meiotic stability and pollen viability in plant species.
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Affiliation(s)
- J Luis Leal
- Plant Ecology and Evolution, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
| | - Pascal Milesi
- Plant Ecology and Evolution, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
- Science for Life Laboratory (SciLifeLab), Uppsala University, 75237 Uppsala, Sweden
| | - Eva Hodková
- Plant Ecology and Evolution, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 16521 Prague, Czech Republic
| | - Qiujie Zhou
- Plant Ecology and Evolution, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
| | - Jennifer James
- Plant Ecology and Evolution, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
| | - D Magnus Eklund
- Physiology and Environmental Toxicology, Department of Organismal Biology, Uppsala University, Norbyvägen 18A, 75236 Uppsala, Sweden
| | - Tanja Pyhäjärvi
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, P.O. Box 65 (Viikinkaari 1), 00014 Helsinki, Finland
- Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Jarkko Salojärvi
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, P.O. Box 65 (Viikinkaari 1), 00014 Helsinki, Finland
| | - Martin Lascoux
- Plant Ecology and Evolution, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
- Science for Life Laboratory (SciLifeLab), Uppsala University, 75237 Uppsala, Sweden
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3
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Dorey T, Frachon L, Rieseberg LH, Kreiner JM, Schiestl FP. Biotic interactions promote local adaptation to soil in plants. Nat Commun 2024; 15:5186. [PMID: 38890322 PMCID: PMC11189560 DOI: 10.1038/s41467-024-49383-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 05/30/2024] [Indexed: 06/20/2024] Open
Abstract
Although different ecological factors shape adaptative evolution in natural habitats, we know little about how their interactions impact local adaptation. Here we used eight generations of experimental evolution with outcrossing Brassica rapa plants as a model system, in eight treatment groups that varied in soil type, herbivory (with/without aphids), and pollination mode (hand- or bumblebee-pollination), to study how biotic interactions affect local adaptation to soil. First, we show that several plant traits evolved in response to biotic interactions in a soil-specific way. Second, using a reciprocal transplant experiment, we demonstrate that significant local adaptation to soil-type evolved in the "number of open flowers", a trait used as a fitness proxy, but only in plants that evolved with herbivory and bee pollination. Whole genome re-sequencing of experimental lines revealed that biotic interactions caused a 10-fold increase in the number of SNPs across the genome with significant allele frequency change, and that alleles with opposite allele frequency change in different soil types (antagonistic pleiotropy) were most common in plants with an evolutionary history of herbivory and bee pollination. Our results demonstrate that the interaction with mutualists and antagonists can facilitate local adaptation to soil type through antagonistic pleiotropy.
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Affiliation(s)
- Thomas Dorey
- Department of Systematic and Evolutionary Botany, University of Zürich, Zürich, Switzerland
- Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Léa Frachon
- Department of Systematic and Evolutionary Botany, University of Zürich, Zürich, Switzerland
- Agroécologie, INRAE, Institut Agro, Univ. Bourgogne, Univ. Bourgogne Franche-Comté, Dijon, France
| | - Loren H Rieseberg
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, Canada
| | - Julia M Kreiner
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, Canada
| | - Florian P Schiestl
- Department of Systematic and Evolutionary Botany, University of Zürich, Zürich, Switzerland.
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4
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Wang C, Yu X, Wang J, Zhao Z, Wan J. Genetic and molecular mechanisms of reproductive isolation in the utilization of heterosis for breeding hybrid rice. J Genet Genomics 2024; 51:583-593. [PMID: 38325701 DOI: 10.1016/j.jgg.2024.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/09/2024]
Abstract
Heterosis, also known as hybrid vigor, is commonly observed in rice crosses. The hybridization of rice species or subspecies exhibits robust hybrid vigor, however, the direct harnessing of this vigor is hindered by reproductive isolation. Here, we review recent advances in the understanding of the molecular mechanisms governing reproductive isolation in inter-subspecific and inter-specific hybrids. This review encompasses the genetic model of reproductive isolation within and among Oryza sativa species, emphasizing the essential role of mitochondria in this process. Additionally, we delve into the molecular intricacies governing the interaction between mitochondria and autophagosomes, elucidating their significant contribution to reproductive isolation. Furthermore, our exploration extends to comprehending the evolutionary dynamics of reproductive isolation and speciation in rice. Building on these advances, we offer a forward-looking perspective on how to overcome the challenges of reproductive isolation and facilitate the utilization of heterosis in future hybrid rice breeding endeavors.
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Affiliation(s)
- Chaolong Wang
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, Jiangsu 210095, China; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiaowen Yu
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, Jiangsu 210095, China
| | - Jian Wang
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zhigang Zhao
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, Jiangsu 210095, China.
| | - Jianmin Wan
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, Jiangsu 210095, China; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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5
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Long Z, Rieseberg LH. Documenting homoploid hybrid speciation. Mol Ecol 2024:e17412. [PMID: 38780141 DOI: 10.1111/mec.17412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/11/2024] [Accepted: 04/30/2024] [Indexed: 05/25/2024]
Abstract
Homoploid hybrid speciation is challenging to document because hybridization can lead to outcomes other than speciation. Thus, some authors have argued that establishment of homoploid hybrid speciation should include evidence that reproductive barriers isolating the hybrid neo-species from its parental species were derived from hybridization. While this criterion is difficult to satisfy, several recent papers have successfully employed a common pipeline to identify candidate genes underlying such barriers and (in one case) to validate their function. We describe this pipeline, its application to several plant and animal species and what we have learned about homoploid hybrid speciation as a consequence. We argue that - given the ubiquity of admixture and the polygenic basis of reproductive isolation - homoploid hybrid speciation could be much more common and more protracted than suggested by earlier conceptual arguments and theoretical studies.
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Affiliation(s)
- Zhiqin Long
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Loren H Rieseberg
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
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6
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Sinaga P, Klichowska E, Nowak A, Nobis M. Hybridization and introgression events in cooccurring populations of closely related grasses (Poaceae: Stipa) in high mountain steppes of Central Asia. PLoS One 2024; 19:e0298760. [PMID: 38412151 PMCID: PMC10898772 DOI: 10.1371/journal.pone.0298760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 01/31/2024] [Indexed: 02/29/2024] Open
Abstract
Stipa is a genus comprising ca. 150 species found in warm temperate regions of the Old World and around 30% of its representatives are of hybrid origin. In this study, using integrative taxonomy approach, we tested the hypothesis that hybridization and introgression are the explanations of the morphological intermediacy in species belonging to Stipa sect. Smirnovia, one of the species-rich sections in the mountains of Central Asia. Two novel nothospecies, S. magnifica × S. caucasica subsp. nikolai and S. lingua × S. caucasica subsp. nikolai, were identified based on a combination of morphological characters and SNPs markers. SNPs marker revealed that all S. lingua × S. caucasica samples were F1 hybrids, whereas most of S. magnifica × S. caucasica samples were backcross hybrids. Furthermore, the above mentioned hybrids exhibit transgressive morphological characters to each of their parental species. These findings have implications for understanding the process of hybridization in the genus Stipa, particularly in the sect. Smirnovia. As a taxonomic conclusion, we describe the two new nothospecies S. × muksuensis (from Tajikistan) and S. × ochyrae (from Kyrgyzstan) and present an identification key to species morphologically similar to the taxa mentioned above.
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Affiliation(s)
- Patar Sinaga
- Institute of Botany, Faculty of Biology, Jagiellonian University, Kraków, Poland
- Doctoral School of Exact and Natural Sciences, Jagiellonian University, Kraków, Poland
| | - Ewelina Klichowska
- Institute of Botany, Faculty of Biology, Jagiellonian University, Kraków, Poland
| | - Arkadiusz Nowak
- Polish Academy of Sciences Botanical Garden – Center for Biological Diversity Conservation in Powsin, Warszawa, Poland
- Botanical Garden of the Wrocław University, Wrocław, Poland
| | - Marcin Nobis
- Institute of Botany, Faculty of Biology, Jagiellonian University, Kraków, Poland
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7
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Albuquerque-Lima S, Lopes AV, Machado IC. Reproductive isolation between two sympatric bat-pollinated Bauhinia (Leguminosae). JOURNAL OF PLANT RESEARCH 2024; 137:65-77. [PMID: 37991585 DOI: 10.1007/s10265-023-01508-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 11/06/2023] [Indexed: 11/23/2023]
Abstract
Several barriers contribute to reproductive isolation between plant species, which can be classified as pre- or post-pollination. Understanding the strength of these barriers could clarify the factors that maintain reproductive isolation and thus species integrity. In this study, we quantified reproductive isolation between two bat-pollinated co-occurring Bauhinia species (B. acuruana and B. pentandra) with similar flower morphology. Over the course of 18 months, we assessed reproductive isolation between these two Bauhinia species by quantifying the individual strengths and absolute contributions of five pre- and post- pollination barriers. Our data showed that both species are completely isolated in their reproduction by a combination of several barriers. Although they co-occur in a few populations, we found a high degree of geographic isolation between them. And although their flowering periods overlap, there is a significant difference in flowering peaks. Both species have the same pollinating bats, but the interspecific transfer of pollen between the plant species may be reduced due to the different length of the flower stamens, resulting in different pollen deposition on the bats' bodies. We have documented complete incompatibility between taxa and conclude that pre- and post-pollination barriers are important factors in preventing gene flow, even in contact zones between these two species of Bauhinia. We highlight that our work is the first study to use methods to estimate the strength of reproductive isolation barriers between bat-pollinated species.
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Affiliation(s)
- Sinzinando Albuquerque-Lima
- Laboratório de Biologia Floral e Reprodutiva and Programa de Pós-Graduação em Biologia Vegetal, Departamento de Botânica, Universidade Federal de Pernambuco, Recife, 50670-901, Pernambuco, Brazil.
- Kunming Institute of Botany, Chinese Academy of Sciences, 123, Lanhei Road, Panlong District, Kunming, 650201, China.
| | - Ariadna Valentina Lopes
- Laboratório de Biologia Floral e Reprodutiva and Programa de Pós-Graduação em Biologia Vegetal, Departamento de Botânica, Universidade Federal de Pernambuco, Recife, 50670-901, Pernambuco, Brazil
| | - Isabel Cristina Machado
- Laboratório de Biologia Floral e Reprodutiva and Programa de Pós-Graduação em Biologia Vegetal, Departamento de Botânica, Universidade Federal de Pernambuco, Recife, 50670-901, Pernambuco, Brazil.
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8
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Fu PC, Twyford AD, Hao YT, Zhang Y, Chen SL, Sun SS. Hybridization and divergent climatic preferences drive divergence of two allopatric Gentiana species on the Qinghai-Tibet Plateau. ANNALS OF BOTANY 2023; 132:1271-1288. [PMID: 37963010 PMCID: PMC10902892 DOI: 10.1093/aob/mcad179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 10/19/2023] [Accepted: 11/13/2023] [Indexed: 11/16/2023]
Abstract
BACKGROUND AND AIMS Exploring how species diverge is vital for understanding the drivers of speciation. Factors such as geographical separation and ecological selection, hybridization, polyploidization and shifts in mating system are all major mechanisms of plant speciation, but their contributions to divergence are rarely well understood. Here we test these mechanisms in two plant species, Gentiana lhassica and G. hoae, with the goal of understanding recent allopatric species divergence on the Qinghai-Tibet Plateau (QTP). METHODS We performed Bayesian clustering, phylogenetic analysis and estimates of hybridization using 561 302 nuclear genomic single nucleotide polymorphisms (SNPs). We performed redundancy analysis, and identified and annotated species-specific SNPs (ssSNPs) to explore the association between climatic preference and genetic divergence. We also estimated genome sizes using flow cytometry to test for overlooked polyploidy. KEY RESULTS Genomic evidence confirms that G. lhassica and G. hoae are closely related but distinct species, while genome size estimates show divergence occurred without polyploidy. Gentiana hoae has significantly higher average FIS values than G. lhassica. Population clustering based on genomic SNPs shows no signature of recent hybridization, but each species is characterized by a distinct history of hybridization with congeners that has shaped genome-wide variation. Gentiana lhassica has captured the chloroplast and experienced introgression with a divergent gentian species, while G. hoae has experienced recurrent hybridization with related taxa. Species distribution modelling suggested range overlap in the Last Interglacial Period, while redundancy analysis showed that precipitation and temperature are the major climatic differences explaining the separation of the species. The species differ by 2993 ssSNPs, with genome annotation showing missense variants in genes involved in stress resistance. CONCLUSIONS This study suggests that the distinctiveness of these species on the QTP is driven by a combination of hybridization, geographical isolation, mating system differences and evolution of divergent climatic preferences.
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Affiliation(s)
- Peng-Cheng Fu
- School of Life Science, Luoyang Normal University, 6 Jiqing Road, Luoyang 471934, P. R. China
| | - Alex D Twyford
- Institute of Ecology and Evolution, The University of Edinburgh, Edinburgh, EH9 3FL, UK
- Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh, EH3 5LR, UK
| | - Yu-Tong Hao
- School of Life Science, Luoyang Normal University, 6 Jiqing Road, Luoyang 471934, P. R. China
| | - Yue Zhang
- School of Life Science, Luoyang Normal University, 6 Jiqing Road, Luoyang 471934, P. R. China
| | - Shi-Long Chen
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, 810001 Xining, P. R. China
| | - Shan-Shan Sun
- School of Life Science, Luoyang Normal University, 6 Jiqing Road, Luoyang 471934, P. R. China
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9
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MacNeill BN, Ortiz-Brunel JP, Rodríguez A, Ruiz-Sánchez E, Navarro-Moreno J, Hofford NP, McKain MR. Floral Diversity and Pollination Syndromes in Agave subgenus Manfreda. Integr Comp Biol 2023; 63:1376-1390. [PMID: 37673672 DOI: 10.1093/icb/icad118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 08/09/2023] [Accepted: 08/19/2023] [Indexed: 09/08/2023] Open
Abstract
The genus Agave is an ecological keystone of American deserts and both culturally and economically important in Mexico. Agave is a large genus of about 250 species. The radiation of Agave is marked by an initial adaptation to desert environments and then a secondary diversification of species associated with pollinator groups, such as hummingbirds and nocturnal moths. Phylogenetic analyses place Agave subgenus Manfreda, or the "herbaceous agaves," in a monophyletic clade that likely evolved in part as an adaptation to novel pollination vectors. Here, we present a morphological and observational study assessing the evolution of floral form in response to pollinator specialization within this understudied group. We found significant visitation by hummingbirds and nocturnal moths to several species within the Agave subgenus Manfreda. These observations also align with our morphological analyses of floral organs and support the evolution of distinct pollination syndromes. We found that not all floral morphology is consistent within a pollination syndrome, suggesting hidden diversity in the evolution of floral phenotypes in Agave. We also characterize the morphological variation between herbarium and live specimens, demonstrating that special consideration needs to be made when combining these types of data. This work identifies the potential for studying the functional evolution of diverse floral forms within Agave and demonstrates the need to further explore ecological and evolutionary relationships to understand pollinator influence on diversification in the genus.
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Affiliation(s)
- Bryan N MacNeill
- Department of Biological Sciences, The University of Alabama, 300 Hackberry Lane, Tuscaloosa, AL 35487, USA
| | | | - Aarón Rodríguez
- Department of Botany and Zoology, University of Guadalajara, Zapopan, Jal. 45200 , Mexico
| | - Eduardo Ruiz-Sánchez
- Department of Botany and Zoology, University of Guadalajara, Zapopan, Jal. 45200 , Mexico
| | - Jesús Navarro-Moreno
- Department of Botany and Zoology, University of Guadalajara, Zapopan, Jal. 45200 , Mexico
| | - Nathaniel P Hofford
- Department of Biological Sciences, The University of Alabama, 300 Hackberry Lane, Tuscaloosa, AL 35487, USA
| | - Michael R McKain
- Department of Biological Sciences, The University of Alabama, 300 Hackberry Lane, Tuscaloosa, AL 35487, USA
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10
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Muniz AC, de Oliveira Buzatti RS, de Lemos-Filho JP, Heuertz M, Nazareno AG, Lovato MB. Genomic signatures of ecological divergence between savanna and forest populations of a Neotropical tree. ANNALS OF BOTANY 2023; 132:523-540. [PMID: 37642427 PMCID: PMC10667007 DOI: 10.1093/aob/mcad120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 08/25/2023] [Indexed: 08/31/2023]
Abstract
BACKGROUND AND AIMS In eastern Neotropical South America, the Cerrado, a large savanna vegetation, and the Atlantic Forest harbour high biodiversity levels, and their habitats are rather different from each other. The biomes have intrinsic evolutionary relationships, with high lineage exchange that can be attributed, in part, to a large contact zone between them. The genomic study of ecotypes, i.e. populations adapted to divergent habitats, can be a model to study the genomic signatures of ecological divergence. Here, we investigated two ecotypes of the tree Plathymenia reticulata, one from the Cerrado and the other from the Atlantic Forest, which have a hybrid zone in the ecotonal zone of Atlantic Forest-Cerrado. METHODS The ecotypes were sampled in the two biomes and their ecotone. The evolutionary history of the divergence of the species was analysed with double-digest restriction site-associated DNA sequencing. The genetic structure and the genotypic composition of the hybrid zone were determined. Genotype-association analyses were performed, and the loci under putative selection and their functions were investigated. KEY RESULTS High divergence between the two ecotypes was found, and only early-generation hybrids were found in the hybrid zone, suggesting a partial reproductive barrier. Ancient introgression between the Cerrado and Atlantic Forest was not detected. The soil and climate were associated with genetic divergence in Plathymenia ecotypes and outlier loci were found to be associated with the stress response, with stomatal and root development and with reproduction. CONCLUSIONS The high genomic, ecological and morphophysiological divergence between ecotypes, coupled with partial reproductive isolation, indicate that the ecotypes represent two species and should be managed as different evolutionary lineages. We advise that the forest species should be re-evaluated and restated as vulnerable. Our results provide insights into the genomic mechanisms underlying the diversification of species across savanna and forest habitats and the evolutionary forces acting in the species diversification in the Neotropics.
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Affiliation(s)
- André Carneiro Muniz
- Departamento de Genética, Ecologia e Evolução, Universidade Federal de Minas Gerais, CP 486, Belo Horizonte, MG 31270-901, Brazil
| | | | - José Pires de Lemos-Filho
- Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Myriam Heuertz
- Biogeco, INRAE, Univ. Bordeaux, 69 route d’Arcachon, 33610 Cestas, France
| | - Alison Gonçalves Nazareno
- Departamento de Genética, Ecologia e Evolução, Universidade Federal de Minas Gerais, CP 486, Belo Horizonte, MG 31270-901, Brazil
| | - Maria Bernadete Lovato
- Departamento de Genética, Ecologia e Evolução, Universidade Federal de Minas Gerais, CP 486, Belo Horizonte, MG 31270-901, Brazil
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11
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Ichida H, Murata H, Hatakeyama S, Yamada A, Ohta A. Near-complete de novo assembly of Tricholoma bakamatsutake chromosomes revealed the structural divergence and differentiation of Tricholoma genomes. G3 (BETHESDA, MD.) 2023; 13:jkad198. [PMID: 37659058 PMCID: PMC10627285 DOI: 10.1093/g3journal/jkad198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 08/08/2023] [Accepted: 08/14/2023] [Indexed: 09/05/2023]
Abstract
Tricholoma bakamatsutake, which is an edible ectomycorrhizal fungus associated with Fagaceae trees, may have diverged before the other species in Tricholoma section Caligata. We generated a highly contiguous whole-genome sequence for T. bakamatsutake SF-Tf05 isolated in an Oak (Quercus salicina) forest in Japan. The assembly of high-fidelity long reads, with a median read length of 12.3 kb, resulted in 13 chromosome-sized contigs comprising 142,068,211 bases with an average guanine and cytosine (GC) content of 43.94%. The 13 chromosomes were predicted to encode 11,060 genes. A contig (122,566 bases) presumably containing the whole circular mitochondrial genome was also recovered. The chromosome-wide comparison of T. bakamatsutake and Tricholoma matsutake (TMA_r1.0) indicated that the basic number of chromosomes (13) was conserved, but the structures of the corresponding chromosomes diverged, with multiple inversions and translocations. Gene conservation and cluster analyses revealed at least 3 phylogenetic clades in Tricholoma section Caligata. Specifically, all T. bakamatsutake strains belonged to the "bakamatsutake" clade, which is most proximal to the "caligatum" clade consisting of Tricholoma caligatum and Tricholoma fulvocastaneum. The constructed highly contiguous nearly telomere-to-telomere genome sequence of a T. bakamatsutake isolate will serve as a fundamental resource for future research on the evolution and differentiation of Tricholoma species.
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Affiliation(s)
- Hiroyuki Ichida
- Ion Beam Breeding Group, RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama 351-0198, Japan
| | - Hitoshi Murata
- Forestry and Forest Products Research Institute (FFPRI), Forest Research and Management Organization, Tsukuba, Ibaraki 305-8687, Japan
| | - Shin Hatakeyama
- Department of Regulatory Biology, Faculty of Science, Saitama University, Saitama, Saitama 338-8570, Japan
| | - Akiyoshi Yamada
- Faculty of Agriculture, Shinshu University, Minami-minowa, Nagano 399-4598, Japan
| | - Akira Ohta
- Kansai Research Center, FFPRI, Kyoto, Kyoto 612-0855, Japan
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12
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Zeng L, Shu W, He H, Li T, Yang X, Li L. Post-pollination barriers contribute to coexistence of partially pollinator-sharing Arisaema species (Araceae). Ecol Evol 2023; 13:e10696. [PMID: 37928192 PMCID: PMC10620566 DOI: 10.1002/ece3.10696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 10/14/2023] [Accepted: 10/19/2023] [Indexed: 11/07/2023] Open
Abstract
Reproductive isolation plays an important role in maintaining the species integrity of sympatric close relatives. For sympatric Arisaema species, interspecific gene flow is expected to be effectively prevented by pre-pollination barriers, particularly strong pollinator isolation mediated by fungus gnats. However, due to the lack of quantitative studies combining multiple pre- and post-pollination barriers, it is not known whether pre-pollination isolation is complete, and whether post-pollination barriers also contribute to reproductive isolation among some Arisaema species. In this study, we quantified the individual strengths and absolute contributions of four pre- and post-pollination barriers (phenological isolation, pollinator isolation, hybrid fruit formation, and hybrid seed formation) among three sympatric Arisaema species (A. bockii, A. lobatum, and A. erubescens). Although phenological isolation and pollinator isolation reduced the frequencies of interspecific pollen transfer among these species, the partial overlap of flowering times and pollinator assemblages resulted in incomplete pre-pollination isolation. Post-pollination barriers also contributed to reproductive isolation at the hybrid fruit and seed formation stages. We propose that, although pre-pollination barriers are expected to contribute more to total isolation than post-pollination barriers in Arisaema, pre-pollination barriers may not completely prevent interspecific pollen transfer among some Arisaema species. Post-pollination barriers, which are generally ignored, may also have contributed significantly to reproductive isolation in Arisaema.
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Affiliation(s)
- Luo Zeng
- College of Biology and Environmental Sciences, Jishou UniversityJishouHunanChina
| | - Wei‐Jie Shu
- College of Biology and Environmental Sciences, Jishou UniversityJishouHunanChina
| | - Hua He
- College of Biology and Environmental Sciences, Jishou UniversityJishouHunanChina
| | - Tao Li
- College of Biology and Environmental Sciences, Jishou UniversityJishouHunanChina
| | - Xiao‐Chen Yang
- College of Biology and Environmental Sciences, Jishou UniversityJishouHunanChina
| | - Li Li
- College of Biology and Environmental Sciences, Jishou UniversityJishouHunanChina
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13
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Farnitano MC, Sweigart AL. Strong postmating reproductive isolation in Mimulus section Eunanus. J Evol Biol 2023; 36:1393-1410. [PMID: 37691442 PMCID: PMC10592011 DOI: 10.1111/jeb.14219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 09/12/2023]
Abstract
Postmating reproductive isolation can help maintain species boundaries when premating barriers to reproduction are incomplete. The strength and identity of postmating reproductive barriers are highly variable among diverging species, leading to questions about their genetic basis and evolutionary drivers. These questions have been tackled in model systems but are less often addressed with broader phylogenetic resolution. In this study we analyse patterns of genetic divergence alongside direct measures of postmating reproductive barriers in an overlooked group of sympatric species within the model monkeyflower genus, Mimulus. Within this Mimulus brevipes species group, we find substantial divergence among species, including a cryptic genetic lineage. However, rampant gene discordance and ancient signals of introgression suggest a complex history of divergence. In addition, we find multiple strong postmating barriers, including postmating prezygotic isolation, hybrid seed inviability and hybrid male sterility. M. brevipes and M. fremontii have substantial but incomplete postmating isolation. For all other tested species pairs, we find essentially complete postmating isolation. Hybrid seed inviability appears linked to differences in seed size, providing a window into possible developmental mechanisms underlying this reproductive barrier. While geographic proximity and incomplete mating isolation may have allowed gene flow within this group in the distant past, strong postmating reproductive barriers today have likely played a key role in preventing ongoing introgression. By producing foundational information about reproductive isolation and genomic divergence in this understudied group, we add new diversity and phylogenetic resolution to our understanding of the mechanisms of plant speciation.
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14
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Bock DG, Cai Z, Elphinstone C, González-Segovia E, Hirabayashi K, Huang K, Keais GL, Kim A, Owens GL, Rieseberg LH. Genomics of plant speciation. PLANT COMMUNICATIONS 2023; 4:100599. [PMID: 37050879 PMCID: PMC10504567 DOI: 10.1016/j.xplc.2023.100599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/21/2023] [Accepted: 04/06/2023] [Indexed: 06/19/2023]
Abstract
Studies of plants have been instrumental for revealing how new species originate. For several decades, botanical research has complemented and, in some cases, challenged concepts on speciation developed via the study of other organisms while also revealing additional ways in which species can form. Now, the ability to sequence genomes at an unprecedented pace and scale has allowed biologists to settle decades-long debates and tackle other emerging challenges in speciation research. Here, we review these recent genome-enabled developments in plant speciation. We discuss complications related to identification of reproductive isolation (RI) loci using analyses of the landscape of genomic divergence and highlight the important role that structural variants have in speciation, as increasingly revealed by new sequencing technologies. Further, we review how genomics has advanced what we know of some routes to new species formation, like hybridization or whole-genome duplication, while casting doubt on others, like population bottlenecks and genetic drift. While genomics can fast-track identification of genes and mutations that confer RI, we emphasize that follow-up molecular and field experiments remain critical. Nonetheless, genomics has clarified the outsized role of ancient variants rather than new mutations, particularly early during speciation. We conclude by highlighting promising avenues of future study. These include expanding what we know so far about the role of epigenetic and structural changes during speciation, broadening the scope and taxonomic breadth of plant speciation genomics studies, and synthesizing information from extensive genomic data that have already been generated by the plant speciation community.
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Affiliation(s)
- Dan G Bock
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Zhe Cai
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Cassandra Elphinstone
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Eric González-Segovia
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | | | - Kaichi Huang
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Graeme L Keais
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Amy Kim
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Gregory L Owens
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Loren H Rieseberg
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada.
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15
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Gawrońska B, Marszałek M, Kosiński P, Podsiedlik M, Bednorz L, Zeyland J. No wonder, it is a hybrid. Natural hybridization between Jacobaea vulgaris and J. erucifolia revealed by molecular marker systems and its potential ecological impact. Ecol Evol 2023; 13:e10467. [PMID: 37664498 PMCID: PMC10468328 DOI: 10.1002/ece3.10467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 08/09/2023] [Accepted: 08/18/2023] [Indexed: 09/05/2023] Open
Abstract
Progressive changes in the environment are related to modifications of the habitat. Introducing exotic species, and interbreeding between species can lead to processes that in the case of rare species or small populations threatens their integrity. Given the declining trends of many populations due to increased hybridization, early recognition of hybrids becomes important in conservation management. Natural hybridization is prevalent in Jacobaea. There are many naturally occurring interspecific hybrids in this genus, including those between Jacobaea vulgaris and its relatives. Although Jacobaea erucifolia and J. vulgaris often co-occur and are considered closely related, apart from the few reports of German botanists on the existence of such hybrids, there is no information on research confirming hybridization between them. Morphologically intermediate individuals, found in the sympatric distributions of J. vulgaris and J. erucifolia, were hypothesized to be their hybrids. Two molecular marker systems (nuclear and chloroplast DNA markers) were employed to test this hypothesis and characterize putative hybrids. Nuclear and chloroplast DNA sequencing results and taxon-specific amplified fragment length polymorphism (AFLP) fragment distribution analysis confirmed the hybrid nature of all 25 putative hybrids. The AFLP patterns of most hybrids demonstrated a closer relationship to J. erucifolia, suggesting frequent backcrossing. Moreover, they showed that several individuals previously described as pure were probably also of hybrid origin, backcrosses to J. erucifolia and J. vulgaris. This study provides the first molecular confirmation that natural hybrids between J. vulgaris and J. erucifolia occur in Poland. Hybridization appeared to be bidirectional but asymmetrical with J. vulgaris as the usual maternal parent.
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Affiliation(s)
- Barbara Gawrońska
- Department of Biochemistry and Biotechnology, Faculty of Agronomy, Horticulture and BioengineeringPoznań University of Life SciencesPoznańPoland
| | - Małgorzata Marszałek
- Department of Biochemistry and Biotechnology, Faculty of Agronomy, Horticulture and BioengineeringPoznań University of Life SciencesPoznańPoland
| | - Piotr Kosiński
- Department of Botany, Faculty of Agronomy, Horticulture and BioengineeringPoznań University of Life SciencesPoznańPoland
- Institute of DendrologyPolish Academy of SciencesKórnikPoland
| | - Marek Podsiedlik
- Natural History Collections, Faculty of BiologyAdam Mickiewicz University in PoznańPoznańPoland
| | - Leszek Bednorz
- Department of Botany, Faculty of Agronomy, Horticulture and BioengineeringPoznań University of Life SciencesPoznańPoland
| | - Joanna Zeyland
- Department of Biochemistry and Biotechnology, Faculty of Agronomy, Horticulture and BioengineeringPoznań University of Life SciencesPoznańPoland
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16
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Yu X, Qin M, Qu M, Jiang Q, Guo S, Chen Z, Shen Y, Fu G, Fei Z, Huang H, Gao L, Yao X. Genomic analyses reveal dead-end hybridization between two deeply divergent kiwifruit species rather than homoploid hybrid speciation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 115:1528-1543. [PMID: 37258460 DOI: 10.1111/tpj.16336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/24/2023] [Accepted: 05/29/2023] [Indexed: 06/02/2023]
Abstract
Despite the importance of hybridization in evolution, the evolutionary consequence of homoploid hybridizations in plants remains poorly understood. Specially, homoploid hybridization events have been rarely documented due to a lack of genomic resources and methodological limitations. Actinidia zhejiangensis was suspected to have arisen from hybridization of Actinidia eriantha and Actinidia hemsleyana or Actinidia rufa. However, this species was very rare in nature and exhibited sympatric distribution with its potential parent species, which implied it might be a spontaneous hybrid of ongoing homoploid hybridization. Here, we illustrate the dead-end homoploid hybridization and genomic basis of isolating barriers between A. eriantha and A. hemsleyana through whole genome sequencing and population genomic analyses. Chromosome-scale genome assemblies of A. zhejiangensis and A. hemsleyana were generated. The chromosomes of A. zhejiangensis are confidently assigned to the two haplomes, and one of them originates from A. eriantha and the other originates from A. hemsleyana. Whole genome resequencing data reveal that A. zhejiangensis are mainly F1 hybrids of A. hemsleyana and A. eriantha and gene flow initiated about 0.98 million years ago, implying both strong genetic barriers and ongoing hybridization between these two deeply divergent kiwifruit species. Five inversions containing genes involved in pollen germination and pollen tube growth might account for the fertility breakdown of hybrids between A. hemsleyana and A. eriantha. Despite its distinct morphological traits and long recurrent hybrid origination, A. zhejiangensis does not initiate speciation. Collectively, our study provides new insights into homoploid hybridization in plants and provides genomic resources for evolutionary and functional genomic studies of kiwifruit.
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Affiliation(s)
- Xiaofen Yu
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, 430070, China
| | - Mengyun Qin
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Minghao Qu
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Quan Jiang
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Sumin Guo
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
| | - Zhenghai Chen
- Forest Resources Monitoring Center of Zhejiang Province, Hangzhou, Zhejiang, 310020, China
| | - Yufang Shen
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
| | - Guodong Fu
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhangjun Fei
- Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, New York, 14853, USA
- U.S. Department of Agriculture-Agricultural Research Service, Robert W. Holley Center for Agriculture and Health, Ithaca, New York, 14853, USA
| | - Hongwen Huang
- Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang, Jiangxi, 332900, China
| | - Lei Gao
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, 430070, China
| | - Xiaohong Yao
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
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17
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Wang C, Wang J, Lu J, Xiong Y, Zhao Z, Yu X, Zheng X, Li J, Lin Q, Ren Y, Hu Y, He X, Li C, Zeng Y, Miao R, Guo M, Zhang B, Zhu Y, Zhang Y, Tang W, Wang Y, Hao B, Wang Q, Cheng S, He X, Yao B, Gao J, Zhu X, Yu H, Wang Y, Sun Y, Zhou C, Dong H, Ma X, Guo X, Liu X, Tian Y, Liu S, Wang C, Cheng Z, Jiang L, Zhou J, Guo H, Jiang L, Tao D, Chai J, Zhang W, Wang H, Wu C, Wan J. A natural gene drive system confers reproductive isolation in rice. Cell 2023; 186:3577-3592.e18. [PMID: 37499659 DOI: 10.1016/j.cell.2023.06.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 02/02/2023] [Accepted: 06/28/2023] [Indexed: 07/29/2023]
Abstract
Hybrid sterility restricts the utilization of superior heterosis of indica-japonica inter-subspecific hybrids. In this study, we report the identification of RHS12, a major locus controlling male gamete sterility in indica-japonica hybrid rice. We show that RHS12 consists of two genes (iORF3/DUYAO and iORF4/JIEYAO) that confer preferential transmission of the RHS12-i type male gamete into the progeny, thereby forming a natural gene drive. DUYAO encodes a mitochondrion-targeted protein that interacts with OsCOX11 to trigger cytotoxicity and cell death, whereas JIEYAO encodes a protein that reroutes DUYAO to the autophagosome for degradation via direct physical interaction, thereby detoxifying DUYAO. Evolutionary trajectory analysis reveals that this system likely formed de novo in the AA genome Oryza clade and contributed to reproductive isolation (RI) between different lineages of rice. Our combined results provide mechanistic insights into the genetic basis of RI as well as insights for strategic designs of hybrid rice breeding.
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Affiliation(s)
- Chaolong Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jian Wang
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jiayu Lu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yehui Xiong
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhigang Zhao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaowen Yu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaoming Zheng
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jing Li
- Food Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650200, China
| | - Qibing Lin
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yulong Ren
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yang Hu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaodong He
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Chao Li
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yonglun Zeng
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Rong Miao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Mali Guo
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Bosen Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ying Zhu
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Yunhui Zhang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Weijie Tang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yunlong Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Benyuan Hao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Qiming Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Siqi Cheng
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaojuan He
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Bowen Yao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Junwen Gao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xufei Zhu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Hao Yu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yong Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yan Sun
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Chunlei Zhou
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Hui Dong
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaoding Ma
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiuping Guo
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xi Liu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yunlu Tian
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Shijia Liu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Chunming Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhijun Cheng
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Ling Jiang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Jiawu Zhou
- Food Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650200, China
| | - Huishan Guo
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Liwen Jiang
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Dayun Tao
- Food Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650200, China
| | - Jijie Chai
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Wei Zhang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Haiyang Wang
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Chuanyin Wu
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Jianmin Wan
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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18
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Gong H, Chang Y, Xu J, Yu X, Gong W. Unilateral cross-incompatibility between Camellia oleifera and C. yuhsienensis provides new insights for hybridization in Camellia spp. FRONTIERS IN PLANT SCIENCE 2023; 14:1182745. [PMID: 37465382 PMCID: PMC10350491 DOI: 10.3389/fpls.2023.1182745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 05/31/2023] [Indexed: 07/20/2023]
Abstract
Camellia yuhsienensis was used to cross with Camellia oleifera to improve the resistance of oil camellia anthracnose. However, unilateral cross-incompatibility (UCI) between C. oleifera and C. yuhsienensis was found during the breeding process. Five C.oleifera cultivars and four C. uhsienensis materials were tested to confirm the UCI between C. oleifera and C. yuhsienensis. 'Huashuo' (HS) and 'Youza 2' (YZ2) were used to represent these two species to characterize the UCI, including pollen tube growth, fertilization and fruit development. The results demonstrated that UCI was prevalent between C. oleifera and C. yuhsienensis. The asynchronous flowering period was a pre-pollination barrier that limited mating between these two species under natural conditions. Interspecific pollen tubes were observed through the styles of these two plants, though the growth rates differed considerably. At 96 hours after pollination, the pollen tube of YZ2 barely entered the ovule, but remained at the base of the style and became swollen. However, the HS pollen tube entered the ovule 48 hours after pollination, double fertilization was observed, and the fruit and seeds developed commonly. Relative to compatible combinations, most unfertilized ovules in incompatible combinations failed to grow, turned brown 150 days after pollination, and the fruits were smaller than expected with uneven enlargement. Investigations on both semi-in vivo and in vitro pollen tubes gave us new idea for thought: the HS style has a stronger inhibitory effect on the interspecific pollen tubes, while calcium alleviates the inhibitory of styles but failed to prevent the appearance of abnormal pollen tube morphology. This study provides useful information on interspecific hybridization between C. oleifera and C. yuhsienensis for understanding reproductive isolation mechanisms and breeding programs in genus Camellia.
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19
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Zou TT, Lyu ST, Jiang QL, Shang SH, Wang XF. Pre- and post-pollination barriers between two exotic and five native Sagittaria species: Implications for species conservation. PLANT DIVERSITY 2023; 45:456-468. [PMID: 37601545 PMCID: PMC10435913 DOI: 10.1016/j.pld.2022.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 10/04/2022] [Accepted: 10/10/2022] [Indexed: 08/22/2023]
Abstract
Anthropogenic introduction of species has resulted in a breakdown of geographical barriers and hybridization in previously allopatric species. Thus, examining hybridization proneness of exotic species contributes to revealing its potential threat. Moreover, reproductive barriers may be strengthened or weakened due to long-term geographical isolation for these newly sympatric species. However, few studies have evaluated multiple barriers between alien and native species. In this study, we quantified the importance of four pre-pollination barriers (phenological, floral traits, pollen production, and floral constancy) and four post-pollination barriers (pollen-pistil incompatibility, seed set, seed viability, and seedling survival) between two introduced and five native Sagittaria species. Results showed that introduced S. platyphylla was cross-compatible with two native species, whereas introduced S. montevidensis was incapable of hybridizing with any native species. Different barriers were asymmetric within species pairs and multiple barriers acted in concert to maintain species boundaries. Post-pollination barriers contributed more to total reproductive isolation in native species, whereas pre-pollination barriers played a stronger role in total reproductive isolation for two introduced species. Seed set was the only barrier that was positively correlated with genetic distance. Our results provide a perspective to better understand reproductive barriers for secondary contact species. We highlight the importance of monitoring hybridization events before human introduction and the possible conservation strategies to remove invasive species with hybridization proneness.
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Affiliation(s)
- Ting-Ting Zou
- Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Sen-Tao Lyu
- Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Qi-Lin Jiang
- Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Shu-He Shang
- Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xiao-Fan Wang
- Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China
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20
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Liu SH, Hung KH, Hsu TW, Hoch PC, Peng CI, Chiang TY. New insights into polyploid evolution and dynamic nature of Ludwigia section Isnardia (Onagraceae). BOTANICAL STUDIES 2023; 64:14. [PMID: 37269434 DOI: 10.1186/s40529-023-00387-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 05/17/2023] [Indexed: 06/05/2023]
Abstract
BACKGROUND While polyploids are common in plants, the evolutionary history and natural dynamics of most polyploid groups are still unclear. Owing to plentiful earlier systematic studies, Ludwigia sect. Isnardia (comprising 22 wetland taxa) is an ideal allopolyploid complex to investigate polyploid evolution and natural dynamics within and among taxa. With a considerable sampling, we concentrated on revisiting earlier phylogenies of Isnardia, reevaluating the earlier estimated age of the most recent common ancestor (TMRCA), exploring the correlation between infraspecific genetic diversity and ploidy levels, and inspecting interspecific gene flows among taxa. RESULTS Phylogenetic trees and network concurred with earlier phylogenies and hypothesized genomes by incorporating 192 atpB-rbcL and ITS sequences representing 91% of Isnardia taxa. Moreover, we detected three multi-origin taxa. Our findings on L. repens and L. sphaerocarpa were consistent with earlier studies; L. arcuata was reported as a multi-origin taxon here, and an additional evolutionary scenario of L. sphaerocarpa was uncovered, both for the first time. Furthermore, estimated Isnardia TMRCA ages based on our data (5.9 or 8.9 million years ago) are in accordance with earlier estimates, although younger than fossil dates (Middle Miocene). Surprisingly, infraspecific genetic variations of Isnardia taxa did not increase with ploidy levels as anticipated from many other polyploid groups. In addition, the exuberant, low, and asymmetrical gene flows among Isnardia taxa indicated that the reproductive barriers may be weakened owing to allopolyploidization, which has rarely been reported. CONCLUSIONS The present research gives new perceptions of the reticulate evolution and dynamic nature of Isnardia and points to gaps in current knowledge about allopolyploid evolution.
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Affiliation(s)
- Shih-Hui Liu
- Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung, 804, Taiwan
| | - Kuo-Hsiang Hung
- Graduate Institute of Bioresources, National Pingtung University of Science and Technology, Pingtung, 912, Taiwan
| | - Tsai-Wen Hsu
- Endemic Species Research Institute, Nantou, 552, Taiwan
| | - Peter C Hoch
- Missouri Botanical Garden, St. Louis, MO, 63166, USA
| | - Ching-I Peng
- Biodiversity Research Center, Academia Sinica, Taipei, 11529, Taiwan
| | - Tzen-Yuh Chiang
- Department of Life Sciences, National Cheng Kung University, Tainan, 701, Taiwan.
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21
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Weng Y, Li H, Yang J, Zhang Z. The past, present, and future of ecogeographic isolation between closely related Aquilegia plants. Ecol Evol 2023; 13:e10098. [PMID: 37250449 PMCID: PMC10212700 DOI: 10.1002/ece3.10098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 03/27/2023] [Accepted: 04/27/2023] [Indexed: 05/31/2023] Open
Abstract
Quantifying the strength of the ecogeographic barrier is an important aspect of plant speciation research, and serves as a practical step to understanding the evolutionary trajectory of plants under climate change. Here, we quantified the extent of ecogeographic isolation in four closely related Aquilegia species that radiated in the Mountains of SW China and adjacent regions, often lacking intrinsic barriers. We used environmental niche models to predict past, present, and future species potential distributions and compared them to determine the degree of overlap and ecogeographic isolation. Our investigation found significant ecological differentiation in all studied species pairs except A. kansuensis and A. ecalacarata. The current strengths of ecogeographic isolation are above 0.5 in most cases. Compared with current climates, most species had an expanding range in the Last Glacial Maximum, the Mid Holocene, and under four future climate scenarios. Our results suggested that ecogeographic isolation contributes to the diversification and maintenance of Aquilegia species in the Mountains of northern and SW China and would act as an essential reproductive barrier in the future.
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Affiliation(s)
- Yulin Weng
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, School of Ecology and Environmental Sciences, Institute of BiodiversityYunnan UniversityKunmingChina
- College of Environment and EcologyXiamen UniversityXiamenChina
| | - Huiqiong Li
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, School of Ecology and Environmental Sciences, Institute of BiodiversityYunnan UniversityKunmingChina
| | - Jiqin Yang
- Gansu Liancheng National Nature ReserveLanzhouChina
| | - Zhi‐Qiang Zhang
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, School of Ecology and Environmental Sciences, Institute of BiodiversityYunnan UniversityKunmingChina
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22
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Messerschmid TFE, Abrahamczyk S, Bañares-Baudet Á, Brilhante MA, Eggli U, Hühn P, Kadereit JW, dos Santos P, de Vos JM, Kadereit G. Inter- and intra-island speciation and their morphological and ecological correlates in Aeonium (Crassulaceae), a species-rich Macaronesian radiation. ANNALS OF BOTANY 2023; 131:697-721. [PMID: 36821492 PMCID: PMC10147336 DOI: 10.1093/aob/mcad033] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 02/22/2023] [Indexed: 05/20/2023]
Abstract
BACKGROUND AND AIMS The most species-rich and ecologically diverse plant radiation on the Canary Islands is the Aeonium alliance (Crassulaceae). In island radiations like this, speciation can take place either within islands or following dispersal between islands. Aiming at quantifying intra- and inter-island speciation events in the evolution of Aeonium, and exploring their consequences, we hypothesized that (1) intra-island diversification resulted in stronger ecological divergence of sister lineages, and that (2) taxa on islands with a longer history of habitation by Aeonium show stronger ecological differentiation and produce fewer natural hybrids. METHODS We studied the biogeographical and ecological setting of diversification processes in Aeonium with a fully sampled and dated phylogeny inferred using a ddRADseq approach. Ancestral areas and biogeographical events were reconstructed in BioGeoBEARS. Eleven morphological characters and three habitat characteristics were taken into account to quantify the morphological and ecological divergence between sister lineages. A co-occurrence matrix of all Aeonium taxa is presented to assess the spatial separation of taxa on each island. KEY RESULTS We found intra- and inter-island diversification events in almost equal numbers. In lineages that diversified within single islands, morphological and ecological divergence was more pronounced than in lineages derived from inter-island diversification, but only the difference in morphological divergence was significant. Those islands with the longest history of habitation by Aeonium had the lowest percentages of co-occurring and hybridizing taxon pairs compared with islands where Aeonium arrived later. CONCLUSIONS Our findings illustrate the importance of both inter- and intra-island speciation, the latter of which is potentially sympatric speciation. Speciation on the same island entailed significantly higher levels of morphological divergence compared with inter-island speciation, but ecological divergence was not significantly different. Longer periods of shared island habitation resulted in the evolution of a higher degree of spatial separation and stronger reproductive barriers.
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Affiliation(s)
- Thibaud F E Messerschmid
- Botanischer Garten München-Nymphenburg, Staatliche Naturwissenschaftliche Sammlungen Bayerns, 80638 München, Germany
- Prinzessin Therese von Bayern-Lehrstuhl für Systematik, Biodiversität & Evolution der Pflanzen, Ludwig-Maximilians-Universität München, 80638 München, Germany
| | - Stefan Abrahamczyk
- Nees-Institut für Biodiversität der Pflanzen, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
- Abteilung Botanik, Staatliches Museum für Naturkunde Stuttgart, 70191 Stuttgart, Germany
| | - Ángel Bañares-Baudet
- Departamento de Botánica, Ecología y Fisiología Vegetal, Universidad de La Laguna, E-38200 La Laguna, Tenerife, Spain
| | - Miguel A Brilhante
- Linking Landscape, Environment, Agriculture and Food (LEAF), Instituto Superior de Agronomia (ISA), Universidade de Lisboa, 1340-017 Lisboa, Portugal
| | - Urs Eggli
- Sukkulenten-Sammlung Zürich/Grün Stadt Zürich, 8002 Zürich, Switzerland
| | - Philipp Hühn
- Institut für Organismische und Molekulare Evolutionsbiologie, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - Joachim W Kadereit
- Institut für Organismische und Molekulare Evolutionsbiologie, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - Patrícia dos Santos
- Centre for Ecology, Evolution and Environmental Changes (cE3c) and Global Change and Sustainability Institute (CHANGE), Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
- Department of Environmental Sciences – Botany, University of Basel, 4056 Basel, Switzerland
| | - Jurriaan M de Vos
- Department of Environmental Sciences – Botany, University of Basel, 4056 Basel, Switzerland
| | - Gudrun Kadereit
- Botanischer Garten München-Nymphenburg, Staatliche Naturwissenschaftliche Sammlungen Bayerns, 80638 München, Germany
- Prinzessin Therese von Bayern-Lehrstuhl für Systematik, Biodiversität & Evolution der Pflanzen, Ludwig-Maximilians-Universität München, 80638 München, Germany
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23
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Spadafora ND, Eggermont D, Křešťáková V, Chenet T, Van Rossum F, Purcaro G. Comprehensive analysis of floral scent and fatty acids in nectar of Silene nutans through modern analytical gas chromatography techniques. J Chromatogr A 2023; 1696:463977. [PMID: 37054636 DOI: 10.1016/j.chroma.2023.463977] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/31/2023] [Accepted: 04/06/2023] [Indexed: 04/15/2023]
Abstract
The aim of this work was to show the potential of multidimensional gas chromatography combined with mass spectrometry and suitable chemometrics means based on untargeted and profiling data analysis to strengthen the information provided by floral scent and nectar fatty acids of four genetically differentiated lineages (E1, W1, W2, and W3) of the nocturnal moth-pollinated herb Silene nutans. Volatile organic compounds emitted by flowers were trapped for a total of 42 samples by in-vivo sampling dynamic head space for analysing floral scent by untargeted approach, while 37 samples of nectar were collected for analysing fatty acids through profiling analysis. The resulting data from floral scent analysis were aligned and compared using a tile-based methodology followed by data mining to access high-level information. Based on floral scent and nectar fatty acid results, it was possible to distinguish E1 from the W lineages, and W3 from W1 and W2. This work puts the bases for a larger study aiming to clarify the existence of prezygotic barriers involved in speciation among lineages of S. nutans, and thus the possible implication of different flower scents and nectar compositions in this phenomenon.
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Affiliation(s)
- Natasha Damiana Spadafora
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, 44121, Ferrara, Italy
| | - Damien Eggermont
- Gembloux Agro-Bio Tech, University of Liège, Passage des Déportés 2, Gembloux, 5030, Belgium
| | - Veronika Křešťáková
- Gembloux Agro-Bio Tech, University of Liège, Passage des Déportés 2, Gembloux, 5030, Belgium; Department of Biochemistry, Faculty of Science, Masaryk University, 32500, Brno, Czech Republic
| | - Tatiana Chenet
- Department of Environment and Prevention Sciences, University of Ferrara, 44121, Ferrara, Italy
| | - Fabienne Van Rossum
- Meise Botanic Garden, Nieuwelaan 38, 1860, Meise, Belgium; Service général de l'Enseignement supérieur et de la Recherche scientifique, Fédération Wallonie-Bruxelles, rue A. Lavallée 1, 1080, Brussels, Belgium
| | - Giorgia Purcaro
- Gembloux Agro-Bio Tech, University of Liège, Passage des Déportés 2, Gembloux, 5030, Belgium.
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24
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Jiménez-López FJ, Arista M, Talavera M, Cerdeira Morellato LP, Pannell JR, Viruel J, Ortiz Ballesteros PL. Multiple pre- and postzygotic components of reproductive isolation between two co-occurring Lysimachia species. THE NEW PHYTOLOGIST 2023; 238:874-887. [PMID: 36683441 DOI: 10.1111/nph.18767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 01/12/2023] [Indexed: 06/17/2023]
Abstract
Genetic divergence between species depends on reproductive isolation (RI) due to traits that reduce interspecific mating (prezygotic isolation) or are due to reduced hybrid fitness (postzygotic isolation). Previous research found that prezygotic barriers tend to be stronger than postzygotic barriers, but most studies are based on the evaluation of F1 hybrid fitness in early life cycle stages. We combined field and experimental data to determine the strength of 17 prezygotic and postzygotic reproductive barriers between two Lysimachia species that often co-occur and share pollinators. We assessed postzygotic barriers up to F2 hybrids and backcrosses. The two species showed near complete RI due to the cumulative effect of multiple barriers, with an uneven and asymmetric contribution to isolation. In allopatry, prezygotic barriers contributed more to reduce gene flow than postzygotic barriers, but their contributions were more similar in sympatry. The strength of postzygotic RI was up to three times lower for F1 progeny than for F2 or backcrossed progenies, and RI was only complete when late F1 stages and either F2 or backcrosses were accounted for. Our results thus suggest that the relative strength of postzygotic RI may be underestimated when its effects on late stages of the life cycle are disregarded.
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Affiliation(s)
- Francisco Javier Jiménez-López
- Department of Plant Biology and Ecology, Faculty of Biology, University of Seville, Apdo. 1095, 41080, Seville, Spain
- Phenology Lab, Department of Biodiversity, Biosciences Institute, UNESP - São Paulo State University, São Paulo, Brazil
| | - Montserrat Arista
- Department of Plant Biology and Ecology, Faculty of Biology, University of Seville, Apdo. 1095, 41080, Seville, Spain
| | - María Talavera
- Department of Plant Biology and Ecology, Faculty of Biology, University of Seville, Apdo. 1095, 41080, Seville, Spain
| | | | - John R Pannell
- Department of Ecology and Evolution, University of Lausanne, Lausanne, CH-1015, Switzerland
| | - Juan Viruel
- Royal Botanic Gardens, Kew, TW9 3DS, Richmond, UK
| | - Pedro L Ortiz Ballesteros
- Department of Plant Biology and Ecology, Faculty of Biology, University of Seville, Apdo. 1095, 41080, Seville, Spain
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25
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Adhikari J, Chandnani R, Vitrakoti D, Khanal S, Ployaram W, Paterson AH. Comparative transmission genetics of introgressed chromatin in reciprocal advanced backcross populations in Gossypium (cotton) polyploids. Heredity (Edinb) 2023; 130:209-222. [PMID: 36754975 PMCID: PMC10076365 DOI: 10.1038/s41437-023-00594-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 01/11/2023] [Accepted: 01/23/2023] [Indexed: 02/10/2023] Open
Abstract
Introgression is a potential source of valuable genetic variation and interspecific introgression lines are important resources for plant breeders to access novel alleles. Experimental advanced-generation backcross populations contain individuals with genomic compositions similar to those resulting from natural interspecific hybridization and provide opportunities to study the nature and transmission pattern of donor chromatin in recipient genomes. Here, we analyze transmission of donor chromatin in reciprocal backcrosses between G. hirsutum and G. barbadense. Across the genome, recurrent backcrossing in both backgrounds yielded donor chromatin at slightly higher frequencies than the Mendelian expectation in BC5F1 plants, while the average frequency of donor alleles in BC5F2 segregating families was less than expected. In the two subgenomes of polyploid cotton, the rate of donor chromatin introgression was similar. Although donor chromatin was tolerated over much of the recipient genomes, 21 regions recalcitrant to donor alleles were identified. Only limited correspondence is observed between the recalcitrant regions in the two backgrounds, suggesting the effect of species background on introgression of donor segments. Genetic breakdown was progressive, with floral abscission and seed inviability ongoing during backcrossing cycles. Regions of either high or low introgression tended to be in terminal chromosomal regions that are generally rich in both genes and crossover events, with long stretches around the centromere having limited crossover activity resulting in relatively constant low introgression frequencies. Constraints on fixation and selection of donor alleles highlights the challenges of utilizing introgression breeding in crop improvement.
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Affiliation(s)
- Jeevan Adhikari
- Plant Genome Mapping Laboratory, Department of Crop and Soil Sciences, University of Georgia, Athens, GA, USA
| | | | - Deepak Vitrakoti
- Plant Genome Mapping Laboratory, Department of Crop and Soil Sciences, University of Georgia, Athens, GA, USA
| | - Sameer Khanal
- Institute of Plant Breeding Genetics and Genomics, Department of Crop and Soil Sciences, University of Georgia, Tifton, GA, USA
| | - Wiriyanat Ployaram
- Plant Genome Mapping Laboratory, Department of Crop and Soil Sciences, University of Georgia, Athens, GA, USA
| | - Andrew H Paterson
- Plant Genome Mapping Laboratory, Department of Crop and Soil Sciences, University of Georgia, Athens, GA, USA.
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26
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Li C, Binaghi M, Pichon V, Cannarozzi G, Brandão de Freitas L, Hanemian M, Kuhlemeier C. Tight genetic linkage of genes causing hybrid necrosis and pollinator isolation between young species. NATURE PLANTS 2023; 9:420-432. [PMID: 36805038 PMCID: PMC10027609 DOI: 10.1038/s41477-023-01354-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 01/19/2023] [Indexed: 05/18/2023]
Abstract
The mechanisms of reproductive isolation that cause phenotypic diversification and eventually speciation are a major topic of evolutionary research. Hybrid necrosis is a post-zygotic isolation mechanism in which cell death develops in the absence of pathogens. It is often due to the incompatibility between proteins from two parents. Here we describe a unique case of hybrid necrosis due to an incompatibility between loci on chromosomes 2 and 7 between two pollinator-isolated Petunia species. Typical immune responses as well as endoplasmic reticulum stress responses are induced in the necrotic line. The locus on chromosome 2 encodes ChiA1, a bifunctional GH18 chitinase/lysozyme. The enzymatic activity of ChiA1 is dispensable for the development of necrosis. We propose that the extremely high expression of ChiA1 involves a positive feedback loop between the loci on chromosomes 2 and 7. ChiA1 is tightly linked to major genes involved in the adaptation to different pollinators, a form of pre-zygotic isolation. This linkage of pre- and post-zygotic barriers strengthens reproductive isolation and probably contributes to rapid diversification and speciation.
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Affiliation(s)
- Chaobin Li
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - Marta Binaghi
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - Vivien Pichon
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Gina Cannarozzi
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
- Chemistry/Biology/Pharmacy Information Center, ETH Zürich, Zürich, Switzerland
| | - Loreta Brandão de Freitas
- Department of Genetics, Laboratory of Molecular Evolution, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Mathieu Hanemian
- Institute of Plant Sciences, University of Bern, Bern, Switzerland.
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), INRAE, CNRS, Université de Toulouse, Castanet-Tolosan, France.
| | - Cris Kuhlemeier
- Institute of Plant Sciences, University of Bern, Bern, Switzerland.
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27
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Pfeilsticker TR, Jones RC, Steane DA, Vaillancourt RE, Potts BM. Molecular insights into the dynamics of species invasion by hybridisation in Tasmanian eucalypts. Mol Ecol 2023; 32:2913-2929. [PMID: 36807951 DOI: 10.1111/mec.16892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/26/2022] [Accepted: 01/26/2023] [Indexed: 02/22/2023]
Abstract
In plants where seed dispersal is limited compared with pollen dispersal, hybridisation may enhance gene exchange and species dispersal. We provide genetic evidence of hybridisation contributing to the expansion of the rare Eucalyptus risdonii into the range of the widespread Eucalyptus amygdalina. These closely related tree species are morphologically distinct, and observations suggest that natural hybrids occur along their distribution boundaries and as isolated trees or in small patches within the range of E. amygdalina. Hybrid phenotypes occur outside the range of normal dispersal for E. risdonii seed, yet in some hybrid patches small individuals resembling E. risdonii occur and are hypothesised to be a result of backcrossing. Using 3362 genome-wide SNPs assessed from 97 individuals of E. risdonii and E. amygdalina and 171 hybrid trees, we show that (i) isolated hybrids match the genotypes expected of F1 /F2 hybrids, (ii) there is a continuum in the genetic composition among the isolated hybrid patches from patches dominated by F1 /F2 -like genotypes to those dominated by E. risdonii-backcross genotypes, and (iii) the E. risdonii-like phenotypes in the isolated hybrid patches are most-closely related to proximal larger hybrids. These results suggest that the E. risdonii phenotype has been resurrected in isolated hybrid patches established from pollen dispersal, providing the first steps in its invasion of suitable habitat by long-distance pollen dispersal and complete introgressive displacement of E. amygdalina. Such expansion accords with the population demographics, common garden performance data, and climate modelling which favours E. risdonii and highlights a role of interspecific hybridisation in climate change adaptation and species expansion.
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Affiliation(s)
- Thais R Pfeilsticker
- School of Natural Sciences and ARC Training Centre for Forest Value, University of Tasmania, Hobart, Tasmania, Australia
| | - Rebecca C Jones
- School of Natural Sciences and ARC Training Centre for Forest Value, University of Tasmania, Hobart, Tasmania, Australia
| | - Dorothy A Steane
- School of Natural Sciences and ARC Training Centre for Forest Value, University of Tasmania, Hobart, Tasmania, Australia
| | - René E Vaillancourt
- School of Natural Sciences and ARC Training Centre for Forest Value, University of Tasmania, Hobart, Tasmania, Australia
| | - Brad M Potts
- School of Natural Sciences and ARC Training Centre for Forest Value, University of Tasmania, Hobart, Tasmania, Australia
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28
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Ferriol M, Simó U, Mansanet CJ, Torres A, Picó B, Monforte AJ, Romero C. Pre- and Post-Zygotic Barriers Contribute to Reproductive Isolation and Correlate with Genetic Distance in Cucumis. PLANTS (BASEL, SWITZERLAND) 2023; 12:926. [PMID: 36840274 PMCID: PMC9963866 DOI: 10.3390/plants12040926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 02/07/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
Hybridization between Cucumis species, including cultivated melon (C. melo), is hampered by Interspecific Reproductive Barriers (IRBs). However, the nature of IRBs in Cucumis is largely unknown. This study explores locations, timing, and contribution to reproductive isolation (RI) of pre- and post-zygotic IRBs in Cucumis. To do this, we assessed crossability among Cucumis African wild species and C. melo at the pre-zygotic level by visualizing pollen tubes under fluorescence microscopy and, post-zygotically, by evaluating fruit/seed set and F1 hybrid fertility. Genetic distances among Cucumis species were inferred from Genotyping-by-Sequencing, and its correlation with RI stages was analyzed. Observed pre- and post-zygotic IRBs included pollen tube arrest, fruit set failure, and hybrid male sterility. Unilateral cross-incongruity/incompatibility (UCI) was detected in some hybridizations, and dominant gene action is suggested for pistil-side UCI in interspecific F1 hybrids. Notably, the allotetraploid C. ficifolius was very fertile as a seed parent but infertile in all reciprocal crosses. Contribution to RI was found significant for both pre- and post-zygotic IRBs. Additionally, a significant positive correlation was detected between genetic distance and pre- and post-zygotic RI stages. Interestingly, UCI offers an accessible system to dissect the genetics of IRBs in Cucumis, which may facilitate the use of wild relatives in breeding.
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Affiliation(s)
- María Ferriol
- Instituto Agroforestal Mediterráneo, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain
| | - Unzué Simó
- Instituto Agroforestal Mediterráneo, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas—Universitat Politècnica de València, c/Fausto Elio s/n, 46022 Valencia, Spain
| | - Carme J. Mansanet
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas—Universitat Politècnica de València, c/Fausto Elio s/n, 46022 Valencia, Spain
| | - Alejandro Torres
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas—Universitat Politècnica de València, c/Fausto Elio s/n, 46022 Valencia, Spain
| | - Belén Picó
- Instituto Universitario de Conservación y Mejora de la Agrodiversidad Valenciana, Universitat Politècnica de València, c/Fausto Elio s/n, 46022 Valencia, Spain
| | - Antonio J. Monforte
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas—Universitat Politècnica de València, c/Fausto Elio s/n, 46022 Valencia, Spain
| | - Carlos Romero
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas—Universitat Politècnica de València, c/Fausto Elio s/n, 46022 Valencia, Spain
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Toll K. An evolutionary framework for understanding habitat partitioning in plants. AMERICAN JOURNAL OF BOTANY 2023; 110:e16119. [PMID: 36585942 PMCID: PMC10107657 DOI: 10.1002/ajb2.16119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 06/17/2023]
Abstract
Many plant species with overlapping geographic ranges segregate at smaller spatial scales. This spatial segregation-zonation when it follows an abiotic gradient and habitat partitioning when it does not-has been experimentally investigated for over a century often using distantly related taxa, such as different genera of algae or barnacles. In those foundational studies, trade-offs between stress tolerance and competitive ability were found to be the major driving factors of habitat partitioning for both animals and plants. Yet, the evolutionary relationships among segregating species are usually not taken into account. Since close relatives are hypothesized to compete more intensely and are more likely to interact during mating compared to distant relatives, the mechanisms underlying habitat partitioning may differ depending on the relatedness of the species in question. Here, I propose an integration of ecological and evolutionary factors contributing to habitat partitioning in plants, specifically how the relative contributions of factors predictably change with relatedness of taxa. Interspecific reproductive interactions in particular are understudied, yet important drivers of habitat partitioning. In spatially segregated species, interspecific mating can reduce the fitness of rare immigrants, preventing their establishment and maintaining patterns of spatial segregation. In this synthesis, I review the literature on mechanisms of habitat partitioning in plants within an evolutionary framework, identifying knowledge gaps and detailing future directions for this rapidly growing field of study.
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Affiliation(s)
- Katherine Toll
- Department of Plant BiologyMichigan State UniversityEast LansingMI48824USA
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Stubbs RL, Theodoridis S, Mora‐Carrera E, Keller B, Yousefi N, Potente G, Léveillé‐Bourret É, Celep F, Kochjarová J, Tedoradze G, Eaton DAR, Conti E. Whole-genome analyses disentangle reticulate evolution of primroses in a biodiversity hotspot. THE NEW PHYTOLOGIST 2023; 237:656-671. [PMID: 36210520 PMCID: PMC10099377 DOI: 10.1111/nph.18525] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Biodiversity hotspots, such as the Caucasus mountains, provide unprecedented opportunities for understanding the evolutionary processes that shape species diversity and richness. Therefore, we investigated the evolution of Primula sect. Primula, a clade with a high degree of endemism in the Caucasus. We performed phylogenetic and network analyses of whole-genome resequencing data from the entire nuclear genome, the entire chloroplast genome, and the entire heterostyly supergene. The different characteristics of the genomic partitions and the resulting phylogenetic incongruences enabled us to disentangle evolutionary histories resulting from tokogenetic vs cladogenetic processes. We provide the first phylogeny inferred from the heterostyly supergene that includes all species of Primula sect. Primula. Our results identified recurrent admixture at deep nodes between lineages in the Caucasus as the cause of non-monophyly in Primula. Biogeographic analyses support the 'out-of-the-Caucasus' hypothesis, emphasizing the importance of this hotspot as a cradle for biodiversity. Our findings provide novel insights into causal processes of phylogenetic discordance, demonstrating that genome-wide analyses from partitions with contrasting genetic characteristics and broad geographic sampling are crucial for disentangling the diversification of species-rich clades in biodiversity hotspots.
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Affiliation(s)
- Rebecca L. Stubbs
- Department of Systematic and Evolutionary BotanyUniversity of ZurichZollikerstrasse 107Zurich8008Switzerland
| | - Spyros Theodoridis
- Senckenberg Biodiversity and Climate Research Centre (SBiK‐F)Frankfurt am Main60325Germany
| | - Emiliano Mora‐Carrera
- Department of Systematic and Evolutionary BotanyUniversity of ZurichZollikerstrasse 107Zurich8008Switzerland
| | - Barbara Keller
- Department of Systematic and Evolutionary BotanyUniversity of ZurichZollikerstrasse 107Zurich8008Switzerland
| | - Narjes Yousefi
- Department of Systematic and Evolutionary BotanyUniversity of ZurichZollikerstrasse 107Zurich8008Switzerland
| | - Giacomo Potente
- Department of Systematic and Evolutionary BotanyUniversity of ZurichZollikerstrasse 107Zurich8008Switzerland
| | - Étienne Léveillé‐Bourret
- Département de Sciences Biologiques, Institut de Recherche en Biologie Végétale (IRBV)Université de MontréalQuébecH1X 2B2Canada
| | - Ferhat Celep
- Department of Biology, Faculty of Arts and SciencesKırıkkale UniversityKırıkkale71450Turkey
| | - Judita Kochjarová
- Department of Phytology, Faculty of ForestryTechnical University in ZvolenZvolen96001Slovak Republic
| | - Giorgi Tedoradze
- Department of Plant Systematics and Geography, Institute of BotanyIlia State UniversityTbilisi0105Georgia
| | - Deren A. R. Eaton
- Department of Ecology, Evolution and Environmental BiologyColumbia UniversityNew YorkNY10027USA
| | - Elena Conti
- Department of Systematic and Evolutionary BotanyUniversity of ZurichZollikerstrasse 107Zurich8008Switzerland
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Perrier A, Willi Y. Intraspecific variation in reproductive barriers between two closely related Arabidopsis sister species. J Evol Biol 2023; 36:121-130. [PMID: 36436201 PMCID: PMC10100320 DOI: 10.1111/jeb.14122] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/07/2022] [Accepted: 09/25/2022] [Indexed: 11/29/2022]
Abstract
Reproductive isolation (RI) is a critical component of speciation and varies strongly in timing and strength among different sister taxa, depending on, for example the geography of speciation and divergence time. However, these factors may also produce variation in timing and strength among populations within species. Here we tested for variation in the expression of RI among replicate population pairs between the sister taxa Arabidopsis lyrata subsp. lyrata and A. arenicola. While the former is predominantly outcrossing, the latter is predominantly selfing. We focused on intrinsic prezygotic and postzygotic RI as both species occur largely in allopatry. We assessed RI by performing within-population crosses and interspecific between-population crosses, and by raising offspring. RI was generally high between all interspecific population pairs, but it varied in timing and strength depending on population history. Prezygotic isolation was strongest between the closest-related population pair, while early postzygotic isolation was high for all other population pairs. Furthermore, the timing and strength of RI depended strongly on cross direction. Our study provides empirical support that reproductive barriers between species are highly variable among population pairs and asymmetric within population pairs, and this variation seems to follow patterns typically described across species pairs.
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Affiliation(s)
- Antoine Perrier
- Department of Environmental Sciences, University of Basel, Basel, Switzerland.,Department of Biology, University of Virginia, Charlottesville, Virginia, USA
| | - Yvonne Willi
- Department of Environmental Sciences, University of Basel, Basel, Switzerland
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32
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Mating system and speciation I: Accumulation of genetic incompatibilities in allopatry. PLoS Genet 2022; 18:e1010353. [PMID: 36520924 PMCID: PMC9799327 DOI: 10.1371/journal.pgen.1010353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 12/29/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022] Open
Abstract
Self-fertilisation is widespread among hermaphroditic species across the tree of life. Selfing has many consequences on the genetic diversity and the evolutionary dynamics of populations, which may in turn affect macroevolutionary processes such as speciation. On the one hand, because selfing increases genetic drift and reduces migration rate among populations, it may be expected to promote speciation. On the other hand, because selfing reduces the efficacy of selection, it may be expected to hamper ecological speciation. To better understand under which conditions and in which direction selfing affects the build-up of reproductive isolation, an explicit population genetics model is required. Here, we focus on the interplay between genetic drift, selection and genetic linkage by studying speciation without gene flow. We test how fast populations with different rates of selfing accumulate mutations leading to genetic incompatibilities. When speciation requires populations to pass through a fitness valley caused by underdominant and compensatory mutations, selfing reduces the depth and/or breadth of the valley, and thus overall facilitates the fixation of incompatibilities. When speciation does not require populations to pass through a fitness valley, as for Bateson-Dobzhanzky-Muller incompatibilities (BDMi), the lower effective population size and higher genetic linkage in selfing populations both facilitate the fixation of incompatibilities. Interestingly, and contrary to intuitive expectations, local adaptation does not always accelerate the fixation of incompatibilities in outcrossing relative to selfing populations. Our work helps to clarify how incompatibilities accumulate in selfing vs. outcrossing lineages, and has repercussions on the pace of speciation as well as on the genetic architecture of reproductive isolation.
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Osmolovsky I, Shifrin M, Gamliel I, Belmaker J, Sapir Y. Eco-Geography and Phenology Are the Major Drivers of Reproductive Isolation in the Royal Irises, a Species Complex in the Course of Speciation. PLANTS (BASEL, SWITZERLAND) 2022; 11:3306. [PMID: 36501345 PMCID: PMC9739335 DOI: 10.3390/plants11233306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 10/30/2022] [Accepted: 11/25/2022] [Indexed: 06/17/2023]
Abstract
The continuous nature of speciation implies that different species are found at different stages of divergence, from no- to complete reproductive isolation. This process and its underlying mechanisms are best viewed in incipient species. Moreover, the species complex can offer unique insight into how reproductive isolation (RI) has evolved. The royal irises (Iris section Oncocyclus) are a young group of species in the course of speciation, providing an ideal system for speciation study. We quantified pre- and post-zygotic reproductive barriers between the eight Israeli species of this complex and estimated the total RI among them. We tested for both pre-pollination and post-pollination reproductive barriers. Pre-pollination barriers, i.e., eco-geographic divergence and phenological differentiation were the major contributors to RI among the Iris species. On the other hand, post-pollination barriers, namely pollen-stigma interactions, fruit set, and seed viability had negligible contributions to total RI. The strength of RI was not uniform across the species complex, suggesting that species may have diverged at different rates. Overall, this study in a young, recently diverged group of species provides insight into the first steps of speciation, suggesting a crucial role of the pre-zygotic barriers.
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Affiliation(s)
- Inna Osmolovsky
- The Botanical Garden, School of Plant Science and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Mariana Shifrin
- The Botanical Garden, School of Plant Science and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Inbal Gamliel
- School of Zoology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Jonathan Belmaker
- School of Zoology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yuval Sapir
- The Botanical Garden, School of Plant Science and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
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Mehravi S, Karimzadeh G, Kordenaeej A, Hanifei M. Mixed-Ploidy and Dysploidy in Hypericum perforatum: A Karyomorphological and Genome Size Study. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11223068. [PMID: 36432797 PMCID: PMC9695836 DOI: 10.3390/plants11223068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 11/11/2022] [Accepted: 11/11/2022] [Indexed: 06/13/2023]
Abstract
Karyomorphology and genome size of 15 St John's wort (Hypericum perforatum L.) populations are reported for the first time. Root tips and fresh young leaves were used for karyological studies and flow cytometric (FCM) measurements, respectively. The chromosome length varied from 0.81 µm to 1.16 µm, and chromosome types were determined as "m". Eight different somatic chromosome numbers were found (2n = 16, 22, 24, 26, 28, 30, 32, 38). Based on the observed basic (x) chromosome numbers of x = 8, 11, 13, 14, 15, 19, this may correspond to diploid (2x), triploid (3x), tetraploid (4x), respectively. Interestingly, we found mixoploidy (3x - 4x) in the root tips of one of the populations. Hybridization, polyploidy and dysploid variation may be the main factors associated with the chromosome number evolution of this species. FCM showed that 2C DNA contents vary from 0.87 to 2.02 pg, showing more than a 2-fold variation. The mean amount of 2C DNA/chromosome and the mean of monoploid genome size were not proportional to ploidy.
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Affiliation(s)
- Shaghayegh Mehravi
- Department of Plant Genetics and Breeding, Faculty of Agriculture, Tarbiat Modares University, Tehran 14115-336, Iran
- School of Biological Sciences, University of Western Australia, Perth, WA 6009, Australia
| | - Ghasem Karimzadeh
- Department of Plant Genetics and Breeding, Faculty of Agriculture, Tarbiat Modares University, Tehran 14115-336, Iran
| | - Alaeddin Kordenaeej
- Department of Agronomy and Plant Breeding, Faculty of Agriculture, University of Shahed, Tehran 33191-18651, Iran
| | - Mehrdad Hanifei
- Department of Plant Genetics and Breeding, Faculty of Agriculture, Tarbiat Modares University, Tehran 14115-336, Iran
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35
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Cornet C, Noret N, Van Rossum F. Pollinator sharing between reproductively isolated genetic lineages of Silene nutans. FRONTIERS IN PLANT SCIENCE 2022; 13:927498. [PMID: 36340351 PMCID: PMC9634645 DOI: 10.3389/fpls.2022.927498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
High reciprocal pollination specialization leading to pollinator isolation can prevent interspecific pollen transfer and competition for pollinators. Sharing pollinators may induce mating costs, but it may also increase pollination services and pollen dispersal and offer more resources to pollinators, which may be important in case of habitat fragmentation leading to pollination disruption. We estimated pollen dispersal and pollinator isolation or sharing between two reproductively isolated genetic lineages of Silene nutans (Caryophyllaceae), which are rare and occur in parapatry in southern Belgium, forming two edaphic ecotypes. As inter-ecotypic crosses may lead to pollen wastage and inviable progeny, pollinator isolation might have evolved between ecotypes. Silene nutans is mainly pollinated by nocturnal moths, including nursery pollinators, which pollinate and lay their eggs in flowers, and whose caterpillars feed on flowers and seeds. Pollinator assemblages of the two ecotypes are largely unknown and inter-ecotypic pollen flows have never been investigated. Fluorescent powdered dyes were used as pollen analogues to quantify intra- and inter-ecotypic pollen transfers and seeds were germinated to detect chlorotic seedlings resulting from inter-ecotypic pollination. Nocturnal pollinators were observed using infrared cameras on the field, and seed-eating caterpillars were collected and reared to identify nursery pollinator species. No pollinator isolation was found: we detected long-distance (up to 5 km) inter-ecotypic dye transfers and chlorotic seedlings, indicating inter-ecotypic fertilization events. The rare moth Hadena albimacula, a nursery pollinator specialized on S. nutans, was found on both ecotypes, as well as adults visiting flowers (cameras recordings) as seed-eating caterpillars. However, S. nutans populations harbor different abundance and diversity of seed predator communities, including other rare nursery pollinators, suggesting a need for distinct conservation strategies. Our findings demonstrate the efficiency of moths, especially of nursery pollinators, to disperse pollen over long distances in natural landscapes, so to ensure gene flow and population sustainability of the host plant. Seed-predator specificities between the two reproductively isolated genetic lineages of S. nutans, and pollinator sharing instead of pollinator isolation when plants occur in parapatry, suggest that conservation of the host plant is also essential for sustaining (rare) pollinator and seed predator communities.
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Affiliation(s)
- Camille Cornet
- Laboratoire d’Ecologie végétale et Biogéochimie, Université libre de Bruxelles, Brussels, Belgium
| | - Nausicaa Noret
- Laboratoire d’Ecologie végétale et Biogéochimie, Université libre de Bruxelles, Brussels, Belgium
| | - Fabienne Van Rossum
- Laboratoire d’Ecologie végétale et Biogéochimie, Université libre de Bruxelles, Brussels, Belgium
- Research Department, Meise Botanic Garden, Meise, Belgium
- Service général de l’Enseignement supérieur et de la Recherche scientifique, Fédération Wallonie-Bruxelles, Brussels, Belgium
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36
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Christie K, Fraser LS, Lowry DB. The strength of reproductive isolating barriers in seed plants: Insights from studies quantifying premating and postmating reproductive barriers over the past 15 years. Evolution 2022; 76:2228-2243. [PMID: 35838076 PMCID: PMC9796645 DOI: 10.1111/evo.14565] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 06/23/2022] [Accepted: 06/30/2022] [Indexed: 01/22/2023]
Abstract
Speciation is driven by the evolution of reproductive isolating barriers that reduce, and ultimately prevent, substantial gene flow between lineages. Despite its central role in evolutionary biology, the process can be difficult to study because it proceeds differently among groups and may occur over long timescales. Due to this complexity, we typically rely on generalizations of empirical data to describe and understand the process. Previous reviews of reproductive isolation (RI) in flowering plants have suggested that prezygotic or extrinsic barriers generally have a stronger effect on reducing gene flow compared to postzygotic or intrinsic barriers. Past conclusions have rested on relatively few empirical estimates of RI; however, RI data have become increasingly abundant over the past 15 years. We analyzed data from recent studies quantifying multiple pre- and postmating barriers in plants and compared the strengths of isolating barriers across 89 taxa pairs using standardized RI metrics. Individual prezygotic barriers were on average stronger than individual postzygotic barriers, and the total strength of prezygotic RI was approximately twice that of postzygotic RI. These findings corroborate that ecological divergence and extrinsic factors, as opposed to solely the accumulation of genetic incompatibilities, are important to speciation and the maintenance of species boundaries in plants. Despite an emphasis in the literature on asymmetric postmating and postzygotic RI, we found that prezygotic barriers acted equally asymmetrically. Overall, substantial variability in the strengths of 12 isolating barriers highlights the great diversity of mechanisms that contribute to plant diversification.
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Affiliation(s)
- Kyle Christie
- Department of Plant BiologyMichigan State UniversityEast LansingMichigan48824,Department of Biological SciencesNorthern Arizona UniversityFlagstaffArizona86011
| | - Linnea S. Fraser
- Department of Plant BiologyMichigan State UniversityEast LansingMichigan48824
| | - David B. Lowry
- Department of Plant BiologyMichigan State UniversityEast LansingMichigan48824
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37
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Van Drunen WE, Friedman J. Autopolyploid establishment depends on life-history strategy and the mating outcomes of clonal architecture. Evolution 2022; 76:1953-1970. [PMID: 35861365 DOI: 10.1111/evo.14582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 06/21/2022] [Accepted: 07/11/2022] [Indexed: 01/22/2023]
Abstract
Polyploidy is a significant component in the evolution of many taxa, particularly plant groups. However, new polyploids face substantial fitness disadvantages due to a lack of same-cytotype mates, and the factors promoting or preventing polyploid establishment in natural populations are often unclear. We develop spatially explicit agent-based simulation models to test the hypothesis that a perennial life history and clonal propagation facilitate the early stages of polyploid establishment and persistence. Our models show that polyploids are more likely to establish when they have longer life spans than diploids, especially when self-fertilization rates are high. Polyploids that combine sexual and clonal reproduction can establish across a wide range of life histories, but their success is moderated by clonal strategy. By tracking individuals and mating events, we reveal that clonal architecture has a substantial impact on the spatial structure of the mixed diploid-polyploid population during polyploid establishment: altering patterns of mating within or between cytotypes via geitonogamous self-fertilization, the mechanisms through which polyploid establishment proceeds, and the final composition of the polyploid population. Overall, our findings provide novel insight into the role of clonal structure in modulating the complex relationship between polyploidy, perenniality, and clonality and offer testable predictions for future empirical work.
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Affiliation(s)
- Wendy E Van Drunen
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada.,Biology Department, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Jannice Friedman
- Biology Department, Queen's University, Kingston, ON, K7L 3N6, Canada
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38
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Xie H, Yang P, Xia Y, Kjellberg F, Darwell CT, Li ZB. Maintenance of specificity in sympatric host-specific fig/wasp pollination mutualisms. PeerJ 2022; 10:e13897. [PMID: 35975234 PMCID: PMC9375967 DOI: 10.7717/peerj.13897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 07/22/2022] [Indexed: 01/19/2023] Open
Abstract
Background Fig/wasp pollination mutualisms are extreme examples of species-specific plant-insect symbioses, but incomplete specificity occurs, with potentially important evolutionary consequences. Why pollinators enter alternative hosts, and the fates of pollinators and the figs they enter, are unknown. Methods We studied the pollinating fig wasp, Ceratosolen emarginatus, which concurrently interacts with its typical host Ficus auriculata and the locally sympatric alternative host F. hainanensis, recording frequencies of the wasp in figs of the alternative hosts. We measured ovipositor lengths of pollinators and style lengths in female and male figs in the two host species. Volatile organic compounds (VOCs) emitted by receptive figs of each species were identified using GC-MS. We tested the attraction of wasps to floral scents in choice experiments, and detected electrophysiologically active compounds by GC-EAD. We introduced C. emarginatus foundresses into figs of both species to reveal the consequences of entry into the alternative host. Results C. emarginatus entered a low proportion of figs of the alternative host, and produced offspring in a small proportion of them. Despite differences in the VOC profiles of the two fig species, they included shared semiochemicals. Although C. emarginatus females prefer receptive figs of F. auriculata, they are also attracted to those of F. hainanensis. C. emarginatus that entered male figs of F. hainanensis produced offspring, as their ovipositors were long enough to reach the bottom of the style; however, broods were larger and offspring smaller than in the typical host. Female figs of F. hainanensis failed to produce seeds when visited by C. emarginatus. These findings advance our current understanding of how these species-specific mutualisms usually remain stable and the conditions that allow their diversification.
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Affiliation(s)
- Hua Xie
- Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Southwest Forestry University, Kunming, Yunnan, China
| | - Pei Yang
- Yunnan University of Chinese Medicine, Kunming, Yunnan, China
| | - Yan Xia
- Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Southwest Forestry University, Kunming, Yunnan, China
| | - Finn Kjellberg
- CEFE, CNRS, Université de Montpellier, EPHE, IRD, Montpellier, France
| | - Clive T. Darwell
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Zong-Bo Li
- Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Southwest Forestry University, Kunming, Yunnan, China
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39
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Wang CH, Zou TT, Liu WQ, Wang XF. The influence of self-pollen deposition on female reproductive success in a self-incompatible plant, Akebia quinata. FRONTIERS IN PLANT SCIENCE 2022; 13:935217. [PMID: 36035715 PMCID: PMC9399832 DOI: 10.3389/fpls.2022.935217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Geitonogamy is inevitable in hermaphrodite and monecious. Even for self-incompatible species, the negative effects of self-pollen are unavoidable when geitonogamous or self-mating occurs. However, the influence of self-pollen on consecutive development of flowers (e.g., fruiting and seeding) was seldom evaluated. Here, the self-incompatible monecious species, Akebia quinata, was used to estimate the influence of self-pollen deposition. We evaluated the extent of pollen limitation and geitonogamous mating under natural conditions by count of stigmatic pollen load and pollen tracking experiment. Hand pollination with different amount and combinations of self vs. cross pollen grains was applied to detect the response of fruit and seed set. The results showed that geitonogamy and pollen limitation occurred under natural conditions in A. quinata. Carpel numbers, ratio of self- and cross-pollen, and the interactive effect of ratio of self- and cross-pollen and total mixed pollen numbers, and not total pollen grain number, determined the effect of self-pollen on female reproductive success. The effect of self-pollen depended on its intensity. In general, the transfer of self-pollen significantly affected young fruit set. However, a little self-pollen together with cross-pollen did not reduce young fruit production. Although self-incompatible plants have evolved physiological mechanisms that reduce self-fertilization, our results provide new insights into the effects of self-pollen and the adaptive significance of self-incompatible monecious species.
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Affiliation(s)
- Chun-Hui Wang
- College of Life Sciences, Wuhan University, Wuhan, China
- Ecology and Environment Monitoring and Scientific Research Center, Yangtze Basin Ecology and Environment Administration, Ministry of Ecology and Environment of the People's Republic of China, Wuhan, China
| | - Ting-Ting Zou
- College of Life Sciences, Wuhan University, Wuhan, China
| | - Wei-Qi Liu
- College of Life Sciences, Wuhan University, Wuhan, China
| | - Xiao-Fan Wang
- College of Life Sciences, Wuhan University, Wuhan, China
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40
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Zhang HP, Tao ZB, Trunschke J, Shrestha M, Scaccabarozzi D, Wang H, Ren ZX. Reproductive Isolation Among Three Nocturnal Moth-Pollinated Sympatric Habenaria Species (Orchidaceae). FRONTIERS IN PLANT SCIENCE 2022; 13:908852. [PMID: 35812980 PMCID: PMC9257206 DOI: 10.3389/fpls.2022.908852] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
Comparison and quantification of multiple pre- and post-pollination barriers to interspecific hybridization are important to understand the factors promoting reproductive isolation. Such isolating factors have been studied recently in many flowering plant species which seek after the general roles and relative strengths of different pre- and post-pollination barriers. In this study, we quantified six isolating factors (ecogeographic isolation, phenological isolation, pollinator isolation, pollinia-pistil interactions, fruit production, and seed development) that could possibly be acting as reproductive barriers at different stages among three sympatric Habenaria species (H. limprichtii, H. davidii, and H. delavayi). These three species overlap geographically but occupy different microhabitats varying in soil water content. They were isolated through pollinator interactions both ethologically (pollinator preference) and mechanically (pollinia attachment site), but to a variable degree for different species pairs. Interspecific crosses between H. limprichtii and H. davidii result in high fruit set, and embryo development suggested weak post-pollination barriers, whereas bidirectional crosses of H. delavayi with either of the other two species fail to produce fruits. Our results revealed that pollinators were the most important isolating barrier including both ethological and mechanical mechanisms, to maintain the boundaries among these three sympatric Habenaria species. Our study also highlights the importance of a combination of pre-and post-pollination barriers for species co-existence in Orchidaceae.
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Affiliation(s)
- Hai-Ping Zhang
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences (CAS), Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zhi-Bin Tao
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences (CAS), Kunming, China
- CAS Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences (CAS), Wuhan, China
| | - Judith Trunschke
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences (CAS), Kunming, China
| | - Mani Shrestha
- Department of Disturbance Ecology, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany
| | - Daniela Scaccabarozzi
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
- School of Molecular and Life Sciences, Curtin University, Bentley, WA, Australia
| | - Hong Wang
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences (CAS), Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
- Lijiang Forest Biodiversity National Observation and Research Station, Lijiang, China
| | - Zong-Xin Ren
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences (CAS), Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
- Lijiang Forest Biodiversity National Observation and Research Station, Lijiang, China
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Brzosko E, Frąckiel K, Jermakowicz E, Mirski P, Ostrowiecka B, Tałałaj I. Pollen transfer and patterns of reproductive success in pure and mixed populations of nectariferous Platanthera bifolia and P. chlorantha (Orchidaceae). PeerJ 2022; 10:e13362. [PMID: 35722265 PMCID: PMC9202541 DOI: 10.7717/peerj.13362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 04/09/2022] [Indexed: 01/13/2023] Open
Abstract
Plant species evolution is driven by many factors that have different roles in space and time. Using different field and laboratory methods, we studied reproductive patterns and their determinants in pure and mixed P. bifolia and P. chlorantha populations in different habitats. We also considered the probability of hybridisation between these two species and the role of intra-population processes in maintaining species integrity. Generally, we found a high level of reproductive success in both Platantherans. In both species, male (MRS) and female (FRS) reproductive success depended on floral display, and male reproductive success additionally on population structure. The flower traits were only weakly related to reproductive success. Moths' assemblages varied spatially and temporally, and their diversity and numbers were correlated with MRS in the year, when their abundance was markedly lower. Analysis of patterns of pollen transfer showed that pollen was transported up to 25 m (average 8.2 ± 4.83 m) and showed gene exchange between these two Platanthera species. The germination level of both species was significantly lower than seed viability, although P. bifolia seed germinated with higher frequency than P. chlorantha seeds. We noted differences in viability and germination of seeds developed as an effect of experimental interspecies crossings and those developed from natural pollination. The presence of intermediate ecotypes together with observations of spontaneous interspecies crosses in the field and viability of seeds produced in interspecies crossing suggest that both pre- and postzygotic reproductive barriers are not complete and do not prevent hybrid production.
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Affiliation(s)
- Emilia Brzosko
- Department of Biology and Plant Ecology, Faculty of Biology, University of Białystok, Białystok, Podlasie, Poland
| | | | - Edyta Jermakowicz
- Department of Biology and Plant Ecology, Faculty of Biology, University of Białystok, Białystok, Podlasie, Poland
| | - Paweł Mirski
- Department of Biology and Plant Ecology, Faculty of Biology, University of Białystok, Białystok, Podlasie, Poland
| | - Beata Ostrowiecka
- Department of Biology and Plant Ecology, Faculty of Biology, University of Białystok, Białystok, Podlasie, Poland
| | - Izabela Tałałaj
- Department of Biology and Plant Ecology, Faculty of Biology, University of Białystok, Białystok, Podlasie, Poland
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Zou TT, Wang CH, Lyu ST, Yu X, Deng LX, Liu WQ, Dai J, Wang XF. Effects of heterospecific pollen on stigma behavior in Campsis radicans: Causes and consequences. AMERICAN JOURNAL OF BOTANY 2022; 109:1004-1015. [PMID: 35567497 DOI: 10.1002/ajb2.1865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 04/18/2022] [Accepted: 04/19/2022] [Indexed: 06/15/2023]
Abstract
PREMISE Pollinator sharing of co-flowering plants may result in interspecific pollen receipt with a fitness cost. However, the underlying factors that determine the effects of heterospecific pollen (HP) are not fully understood. Moreover, the cost of stigma closure induced by HP may be more severe for plants with special touch-sensitive stigmas than for plants with non-touch-sensitive stigmas. Very few studies have assessed HP effects on stigma behavior. METHODS We conducted hand-pollination experiments with 10 HP donors to estimate HP effects on stigma behavior and stigmatic pollen germination in Campsis radicans (Bignoniaceae) at low and high pollen loads. We assessed the role of phylogenetic distance between donor and recipient, pollen size, and pollen aperture number in mediating HP effects. Additionally, we observed pollen tube growth to determine the conspecific pollen-tube-growth advantage. RESULTS Stigma behavior differed significantly with HP of different species. Pollen load increased, while pollen size decreased, the percentage of permanent closure and stigmatic germination of HP. Stigmatic HP germination increased with increasing aperture number. However, HP effects did not depend on phylogenetic distance. In addition, conspecific pollen had a pollen-tube-growth advantage over HP. CONCLUSIONS Our results provide a good basis for understanding the stigma-pollen recognition process of plant taxa with touch-sensitive stigmas. We concluded that certain flowering traits drive the HP effects on the post-pollination period. To better understand the impact of pollinator sharing and interspecific pollen transfer on plant evolution, we highlight the importance of evaluating more factors that determine HP effects at the community level.
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Affiliation(s)
- Ting-Ting Zou
- Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Chun-Hui Wang
- Ecology and Environment Monitoring and Scientific Research Center, Yangtze Basin Ecology and Environment Administration, Ministry of Ecology and Environment of the People's Republic of China, Wuhan, 430010, China
| | - Sen-Tao Lyu
- Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Xiaolei Yu
- State Key Laboratory of Hybrid Rice, Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Lu-Xi Deng
- Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Wei-Qi Liu
- Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Jie Dai
- Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Xiao-Fan Wang
- Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
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43
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Wu JF, Jia DR, Liu RJ, Zhou ZL, Wang LL, Chen MY, Meng LH, Duan YW. Multiple lines of evidence supports the two varieties of Halenia elliptica (Gentianaceae) as two species. PLANT DIVERSITY 2022; 44:290-299. [PMID: 35769593 PMCID: PMC9209875 DOI: 10.1016/j.pld.2021.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 09/03/2021] [Accepted: 09/07/2021] [Indexed: 06/15/2023]
Abstract
Delimiting species requires multiple sources of evidence. Here, we delimited two varieties of Halenia elliptica (Gentianaceae) using several lines of evidence, including morphological traits and mating system in a sympatric population, phylogenetic relationships based on nrITS and cpDNA (rpl16) data, and complete chloroplast genome sequences. Comparative analysis of 21 morphological traits clearly separates the two varieties of H. elliptica. Examination of the flowering process and pollination treatments indicate that H. elliptica var. grandiflora produces seeds via outcrossing, whereas H. elliptica var. elliptica produces seeds via mixed mating. Furthermore, hand-pollinated hybridization of the two varieties produced no seeds. Observations of pollinators showed that when bees began a pollination bout on H. elliptica var. grandiflora they preferred to continue pollinating this variety; however, when they began a pollination bout on H. elliptica var. elliptica, they showed no preference for either variety. Phylogenetic analysis confirmed the monophyly of H. elliptica, which was further divided into two monophyletic clades corresponding to the two varieties. A large number of variants from the chloroplast genomes reflected remarkable genetic dissimilarities between the two varieties of H. elliptica. We recommend that the two varieties of H. elliptica should be revised as two species (H. elliptica and H. grandiflora). Our findings indicate that H. elliptica varieties may have split into two separate species due to a shift in mating system, changes in flowering phenology and/or post-pollination reproductive isolation.
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Affiliation(s)
- Jin-Feng Wu
- School of Life Sciences, Yunnan Normal University, Kunming 650092, PR China
| | - Dong-Rui Jia
- School of Ecology and Environmental Science & Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, Yunnan University, Kunming 650091, PR China
| | - Rui-Juan Liu
- Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810001, PR China
| | - Zhi-Li Zhou
- The Germplasm Bank of Wild Species, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, PR China
| | - Lin-Lin Wang
- The Germplasm Bank of Wild Species, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, PR China
| | - Min-Yu Chen
- The Germplasm Bank of Wild Species, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, PR China
| | - Li-Hua Meng
- School of Life Sciences, Yunnan Normal University, Kunming 650092, PR China
| | - Yuan-Wen Duan
- The Germplasm Bank of Wild Species, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, PR China
- Yunnan Lijiang Forest Ecosystem National Observation and Research Station, Kunming Institute of Botany, Chinese Academy of Sciences, Lijiang 674100, Yunnan, PR China
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44
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Hopkins R. Predicting how pollinator behavior causes reproductive isolation. Ecol Evol 2022; 12:e8847. [PMID: 35462980 PMCID: PMC9019001 DOI: 10.1002/ece3.8847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 04/06/2022] [Indexed: 11/07/2022] Open
Abstract
Pollinator behavior is an important contributor to plants speciation, yet how variation in pollinator behavior causes variation in reproductive isolation (RI) is largely uncharacterized. Here I present a model that predicts how two aspects of pollinator behavior, constancy and preference, contribute to a barrier to reproduction in plants. This model is motivated by two observations: most co‐occurring plants vary in frequency over space and time, and most plants have multiple pollinators that differ in behavior. Thus, my goal was to understand how relative frequencies of plants and pollinators in a community influence ethological RI between co‐occurring plants. I find that RI for a focal plant generally increases with increasing relative plant frequency, but the shape of this relationship is highly dependent on the strength of pollinator behavior (constancy and preference). Additionally, when multiple pollinators express different behavior, I find that pollinators with stronger preference disproportionately influence RI. But, I show that RI caused by constancy is the average RI predicted from constancy of each pollinator weighted by pollinator frequency. I apply this model to examples of pollinator‐mediated RI in Phlox and in Ipomopsis to predict the relationships between plant frequency and ethological RI in natural systems. This model provides new insights into how and why pollinator specialization causes RI, and how RI could change with changing biological communities.
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Affiliation(s)
- Robin Hopkins
- The Department of Organismic and Evolutionary Biology and The Arnold ArboretumHarvard UniversityBostonMassachusettsUSA
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45
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Wang Z, Kang M, Li J, Zhang Z, Wang Y, Chen C, Yang Y, Liu J. Genomic evidence for homoploid hybrid speciation between ancestors of two different genera. Nat Commun 2022; 13:1987. [PMID: 35418567 PMCID: PMC9008057 DOI: 10.1038/s41467-022-29643-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 03/25/2022] [Indexed: 11/29/2022] Open
Abstract
Homoploid hybrid speciation (HHS) has been increasingly recognized as occurring widely during species diversification of both plants and animals. However, previous studies on HHS have mostly focused on closely-related species while it has been rarely reported or tested between ancestors of different genera. Here, we explore the likely HHS origin of Carpinus sect. Distegocarpus between sect. Carpinus and Ostrya in the family Betulaceae. We generate a chromosome-level reference genome for C. viminea of sect. Carpinus and re-sequence genomes of 44 individuals from the genera Carpinus and Ostrya. Our integrated analyses of all genomic data suggest that sect. Distegocarpus, which has three species, likely originates through HHS during the early divergence between Carpinus and Ostrya. Our study highlights the likelihood of an HHS event between ancestors of the extant genera during their initial divergences, which may have led to reticulate phylogenies at higher taxonomic levels.
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Affiliation(s)
- Zefu Wang
- State Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Minghui Kang
- State Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Jialiang Li
- State Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Zhiyang Zhang
- State Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Yufei Wang
- State Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Chunlin Chen
- State Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Yongzhi Yang
- State Key Laboratory of Grassland Agro-Ecosystem, College of Ecology, Lanzhou University, Lanzhou, Gansu, China
| | - Jianquan Liu
- State Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China.
- State Key Laboratory of Grassland Agro-Ecosystem, College of Ecology, Lanzhou University, Lanzhou, Gansu, China.
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46
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Yamaguchi R. Intermediate dispersal hypothesis of species diversity: New insights. Ecol Res 2022. [DOI: 10.1111/1440-1703.12313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ryo Yamaguchi
- Department of Advanced Transdisciplinary Science Hokkaido University Sapporo Japan
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47
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Hornych O, Férová A, Hori K, Košnar J, Ekrt L. Apomictic fern fathers: an experimental approach to the reproductive characteristics of sexual, apomict, and hybrid fern gametophytes. AMERICAN JOURNAL OF BOTANY 2022; 109:628-644. [PMID: 35072270 DOI: 10.1002/ajb2.1817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 01/05/2022] [Accepted: 01/13/2022] [Indexed: 06/14/2023]
Abstract
PREMISE Apomixis and hybridization are two essential and complementary factors in the evolution of plants, including ferns. Hybridization combines characteristics from different species, while apomixis conserves features within a lineage. When combined, these two processes result in apo-sex hybrids. The conditions leading to the formation of these hybrids are poorly understood in ferns. METHODS We cultivated spores from 66 fern samples (43 apomicts, 7 apo-sex hybrids, and 16 sexuals), and measured their development in vitro over 16 weeks. We evaluated germination, lateral meristem formation rates, sexual expression, and production of sporophytes and then compared ontogenetic patterns among the three groups. RESULTS The three examined groups formed antheridia (male gametangia) but differed in overall gametophyte development. Sexual species created archegonia (female, 86% of viable samples), but no sporophytes. Apomicts rarely created nonfunctional archegonia (8%) but usually produced apogamous sporophytes (75%). Surprisingly, apomictic and sexual species showed similar development speed. The sexually reproducing parents of viable studied hybrids formed about twice as many meristic gametophytes as the apomictic parents (39% vs. 20%, respectively). CONCLUSIONS We present the most thorough comparison of gametangial development of sexual and apomictic ferns, to date. Despite expectations, apomictic reproduction might not lead to earlier sporophyte formation. Apomicts produce functional sperm and thus can contribute this type of gamete to their hybrids. The development patterns found in the parents of hybrids indicate a possible increase of hybridization rates by antheridiogens. The apo-sex hybrids always inherit the apomictic reproductive strategy and are thus capable of self-perpetuation.
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Affiliation(s)
- Ondřej Hornych
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice, CZ-37005, Czech Republic
| | - Alžběta Férová
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice, CZ-37005, Czech Republic
| | - Kiyotaka Hori
- The Kochi prefectural Makino Botanical Garden, Godaisan 4200-6, Kochi, 781-8125, Japan
| | - Jiří Košnar
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice, CZ-37005, Czech Republic
| | - Libor Ekrt
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice, CZ-37005, Czech Republic
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48
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Wang Z, Jiang Y, Yang X, Bi H, Li J, Mao X, Ma Y, Ru D, Zhang C, Hao G, Wang J, Abbott RJ, Liu J. Molecular signatures of parallel adaptive divergence causing reproductive isolation and speciation across two genera. Innovation (N Y) 2022; 3:100247. [PMID: 35519515 PMCID: PMC9065898 DOI: 10.1016/j.xinn.2022.100247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 04/16/2022] [Indexed: 11/18/2022] Open
Abstract
Parallel evolution of reproductive isolation (PERI) provides strong evidence for natural selection playing a fundamental role in the origin of species. However, PERI has been rarely demonstrated for well established species drawn from different genera. In particular, parallel molecular signatures for the same genes in response to similar habitat divergence in such different lineages is lacking. Here, based on whole-genome sequencing data, we first explore the speciation process in two sister species of Carpinus (Betulaceae) in response to divergence for temperature and soil-iron concentration in habitats they occupy in northern and southwestern China, respectively. We then determine whether parallel molecular mutations occur during speciation in this pair of species and also in another sister-species pair of the related genus, Ostryopsis, which occupy similarly divergent habitats in China. We show that gene flow occurred during the origin of both pairs of sister species since approximately 9.8 or approximately 2 million years ago, implying strong natural selection during divergence. Also, in both species pairs we detected concurrent positive selection in a gene (LHY) for flowering time and in two paralogous genes (FRO4 and FRO7) of a gene family known to be important for iron tolerance. These changes were in addition to changes in other major genes related to these two traits. The different alleles of these particular candidate genes possessed by the sister species of Carpinus were functionally tested and indicated likely to alter flowering time and iron tolerance as previously demonstrated in the pair of Ostryopsis sister species. Allelic changes in these genes may have effectively resulted in high levels of prezygotic reproductive isolation to evolve between sister species of each pair. Our results show that PERI can occur in different genera at different timescales and involve similar signatures of molecular evolution at genes or paralogues of the same gene family, causing reproductive isolation as a consequence of adaptation to similarly divergent habitats. PERI provides strong evidence for natural selection playing a fundamental role in the origin of species PERI is rarely demonstrated for well-established species drawn from different genera We detected PERI across two genera (Carpinus and Ostryopsis) in the family Betulaceae PERI can occur in different genera at different timescales and involve molecular signatures at similar pathways
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Affiliation(s)
- Zefu Wang
- State Key Laboratory of Grassland Agro-Ecosystem, College of Ecology, Lanzhou University, Lanzhou 730000, China
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, China
| | - Yuanzhong Jiang
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, China
| | - Xiaoyue Yang
- State Key Laboratory of Grassland Agro-Ecosystem, College of Ecology, Lanzhou University, Lanzhou 730000, China
| | - Hao Bi
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, China
| | - Jialiang Li
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, China
| | - Xingxing Mao
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, China
| | - Yazhen Ma
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, China
| | - Dafu Ru
- State Key Laboratory of Grassland Agro-Ecosystem, College of Ecology, Lanzhou University, Lanzhou 730000, China
| | - Cheng Zhang
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, China
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Guoqian Hao
- Sichuan Tea College, Yibin University, Yibin 644000, China
| | - Jing Wang
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, China
| | | | - Jianquan Liu
- State Key Laboratory of Grassland Agro-Ecosystem, College of Ecology, Lanzhou University, Lanzhou 730000, China
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, China
- Corresponding author
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49
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Joffard N, Olofsson C, Friberg M, Sletvold N. Extensive pollinator sharing does not promote character displacement in two orchid congeners. Evolution 2022; 76:749-764. [PMID: 35188979 DOI: 10.1111/evo.14446] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 01/07/2022] [Accepted: 01/18/2022] [Indexed: 01/22/2023]
Abstract
Pollinator sharing between close relatives can be costly and can promote pollination niche partitioning and floral divergence. This should be reflected by a higher species divergence in sympatry than in allopatry. We tested this hypothesis in two orchid congeners with overlapping distributions and flowering times. We characterized floral traits and pollination niches and quantified pollen limitation in 15 pure and mixed populations, and we measured phenotypic selection on floral traits and performed controlled crosses in one mixed site. Most floral traits differed between species, yet pollinator sharing was extensive. Only the timing of scent emission diverged more in mixed sites than in pure sites, and this was not mirrored by the timing of pollinator visitation. We did not detect divergent selection on floral traits. Seed production was pollen limited in most populations but not more severely in mixed sites than in pure sites. Interspecific crosses produced the same or a higher proportion of viable seeds than intraspecific crosses. The two orchid species attract the same pollinator species despite showing divergent floral traits. However, this does not promote character displacement, implying a low cost of pollinator sharing. Our results highlight the importance of characterizing both traits and ecological niches in character displacement studies.
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Affiliation(s)
- Nina Joffard
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, Uppsala, 752 36, Sweden.,University of Lille, UMR 8198 - Evo-Eco-Paleo, Villeneuve d'Ascq, F-59655, France
| | - Caroliné Olofsson
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, Uppsala, 752 36, Sweden
| | - Magne Friberg
- Department of Biology, Lund University, Lund, SE-223 62, Sweden
| | - Nina Sletvold
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, Uppsala, 752 36, Sweden
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50
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Kolis KM, Berg CS, Nelson TC, Fishman L. Population genomic consequences of life-history and mating system adaptation to a geothermal soil mosaic in yellow monkeyflowers. Evolution 2022; 76:765-781. [PMID: 35266558 DOI: 10.1111/evo.14469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 01/13/2022] [Accepted: 01/26/2022] [Indexed: 01/21/2023]
Abstract
Local selection can promote phenotypic divergence despite gene flow across habitat mosaics, but adaptation itself may generate substantial barriers to genetic exchange. In plants, life-history, phenology, and mating system divergence have been proposed to promote genetic differentiation in sympatry. In this study, we investigate phenotypic and genetic variation in Mimulus guttatus (yellow monkeyflowers) across a geothermal soil mosaic in Yellowstone National Park (YNP). Plants from thermal annual and nonthermal perennial habitats were heritably differentiated for life-history and mating system traits, consistent with local adaptation to the ephemeral thermal-soil growing season. However, genome-wide genetic variation primarily clustered plants by geographic region, with little variation sorting by habitat. The one exception was an extreme thermal population also isolated by a 200 m geographical gap of no intermediate habitat. Individual inbreeding coefficients (FIS ) were higher (and predicted by trait variation) in annual plants and annual pairs showed greater isolation by distance at local (<1 km) scales. Finally, YNP adaptation does not reuse a widespread inversion that underlies M. guttatus life-history ecotypes range-wide, suggesting a novel genetic mechanism. Overall, this work suggests that life-history and mating system adaptation strong enough to shape individual mating patterns does not necessarily generate incipient speciation without geographical barriers.
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Affiliation(s)
- Kory M Kolis
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812.,Current Address: O'Connor Center for the Rocky Mountain West, University of Montana, Missoula, MT, 59812
| | - Colette S Berg
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812
| | - Thomas C Nelson
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812.,Current Address: Embark Veterinary, Inc., Boston, Massachusetts, 02210
| | - Lila Fishman
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812
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