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Wang M, Zhu M, Qian J, Yang Z, Shang F, Egan AN, Li P, Liu L. Phylogenomics of mulberries (Morus, Moraceae) inferred from plastomes and single copy nuclear genes. Mol Phylogenet Evol 2024; 197:108093. [PMID: 38740145 DOI: 10.1016/j.ympev.2024.108093] [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: 08/01/2023] [Revised: 04/30/2024] [Accepted: 05/06/2024] [Indexed: 05/16/2024]
Abstract
Mulberries (genus Morus), belonging to the order Rosales, family Moraceae, are important woody plants due to their economic values in sericulture, as well as for nutritional benefits and medicinal values. However, the taxonomy and phylogeny of Morus, especially for the Asian species, remains challenging due to its wide geographical distribution, morphological plasticity, and interspecific hybridization. To better understand the evolutionary history of Morus, we combined plastomes and a large-scale nuclear gene analyses to investigate their phylogenetic relationships. We assembled the plastomes and screened 211 single-copy nuclear genes from 13 Morus species and related taxa. The plastomes of Morus species were relatively conserved in terms of genome size, gene content, synteny, IR boundary and codon usage. Using nuclear data, our results elucidated identical topologies based on coalescent and concatenation methods. The genus Morus was supported as monophyletic, with M. notabilis as the first diverging lineage and the two North American Morus species, M. microphylla and M. rubra, as sister to the other Asian species. In the Asian Morus species, interspecific relationships were completely resolved. However, cyto-nuclear discordances and gene tree-species tree conflicts were detected in the phylogenies of Morus, with multiple evidences supporting hybridization/introgression as the main cause of discordances between nuclear and plastid phylogenies, while gene tree-species tree conflicts were mainly caused by ILS.
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Affiliation(s)
- Meizhen Wang
- College of Life Sciences, Henan Normal University, Xinxiang 453000, China; Systematic & Evolutionary Botany and Biodiversity Group, MOE Key Laboratory of Biosystems Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Mengmeng Zhu
- Laboratory of Plant Germplasm and Genetic Engineering, School of Life Sciences, Henan University, Kaifeng 475001, China
| | - Jiayi Qian
- College of Life Sciences, Henan Agricultural University, Zhengzhou 450002, China
| | - Zhaoping Yang
- College of Life Sciences and Technologies, Tarim University, Alar 843300, China
| | - Fude Shang
- Laboratory of Plant Germplasm and Genetic Engineering, School of Life Sciences, Henan University, Kaifeng 475001, China; College of Life Sciences, Henan Agricultural University, Zhengzhou 450002, China.
| | - Ashley N Egan
- Department of Biology, Utah Valley University, Orem, UT 84058, United States.
| | - Pan Li
- Systematic & Evolutionary Botany and Biodiversity Group, MOE Key Laboratory of Biosystems Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Luxian Liu
- College of Life Sciences, Henan Normal University, Xinxiang 453000, China; Laboratory of Plant Germplasm and Genetic Engineering, School of Life Sciences, Henan University, Kaifeng 475001, China.
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Lakušić D, Zbiljić M, Šatović Z, Kuzmanović N, Liber Z. Asymmetric Introgression and Cryptic Natural Hybridization between Two Species of Teucrium Section Polium (Lamiaceae) on the Balkan Peninsula. PLANTS (BASEL, SWITZERLAND) 2024; 13:1617. [PMID: 38931049 PMCID: PMC11207346 DOI: 10.3390/plants13121617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 06/01/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024]
Abstract
In this work, we analyzed the morphology and genetic structure of Teucrium montanum, T. capitatum and their hybrid T. × rohlenae from three syntopic populations. A morphometric study showed that the parents and their hybrids exhibited continuous morphological variation, with the hybrid positioned exactly between the parents. Genetic analysis revealed that plants morphologically identified as T. × rohlenae are fertile hybrids that produce hybrid swarms dominated by later-generation hybrids. This suggests that introgression, rather than speciation, is the more likely outcome of hybridization between these plant species. The extent and direction of gene flow between the two species differed markedly between the three syntopic localities. At the Trilj locality, it was clearly unidirectional, with T. capitatum playing the dominant role. At the Sićevo locality, gene flow was slightly asymmetric, favoring the genetic background of T. capitatum, while at the Sliven site, it was completely asymmetric in the opposite direction. The extreme case of unidirectional gene flow was observed at the Trilj locality where plants morphologically identified as T. montanum could not be genetically distinguished from T. capitatum. This suggests that interspecific hybridization occurred long ago, leading to introgression and cryptic hybrids, blurring of species boundaries and generating evolutionary noise.
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Affiliation(s)
- Dmitar Lakušić
- Institute of Botany and Botanical Garden, Faculty of Biology, University of Belgrade, Takovska 43, 11000 Belgrade, Serbia; (D.L.); (N.K.)
| | - Miloš Zbiljić
- Department of Botany, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11060 Belgrade, Serbia;
| | - Zlatko Šatović
- Department of Plant Biodiversity, Faculty of Agriculture, University of Zagreb, Svetošimunska 25, 10000 Zagreb, Croatia;
- Centre of Excellence for Biodiversity and Molecular Plant Breeding (CroP-BioDiv), Svetošimunska 25, 10000 Zagreb, Croatia
| | - Nevena Kuzmanović
- Institute of Botany and Botanical Garden, Faculty of Biology, University of Belgrade, Takovska 43, 11000 Belgrade, Serbia; (D.L.); (N.K.)
| | - Zlatko Liber
- Centre of Excellence for Biodiversity and Molecular Plant Breeding (CroP-BioDiv), Svetošimunska 25, 10000 Zagreb, Croatia
- Division of Botany, Department of Biology, Faculty of Science, University of Zagreb, Marulićev trg 9A, 10000 Zagreb, Croatia
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Sianta SA, Moeller DA, Brandvain Y. The extent of introgression between incipient Clarkia species is determined by temporal environmental variation and mating system. Proc Natl Acad Sci U S A 2024; 121:e2316008121. [PMID: 38466849 PMCID: PMC10963018 DOI: 10.1073/pnas.2316008121] [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: 09/18/2023] [Accepted: 02/07/2024] [Indexed: 03/13/2024] Open
Abstract
Introgression is pervasive across the tree of life but varies across taxa, geography, and genomic regions. However, the factors modulating this variation and how they may be affected by global change are not well understood. Here, we used 200 genomes and a 15-y site-specific environmental dataset to investigate the effects of environmental variation and mating system divergence on the magnitude of introgression between a recently diverged outcrosser-selfer pair of annual plants in the genus Clarkia. These sister taxa diverged very recently and subsequently came into secondary sympatry where they form replicated contact zones. Consistent with observations of other outcrosser-selfer pairs, we found that introgression was asymmetric between taxa, with substantially more introgression from the selfer to the outcrosser. This asymmetry was caused by a bias in the direction of initial F1 hybrid formation and subsequent backcrossing. We also found extensive variation in the outcrosser's admixture proportion among contact zones, which was predicted nearly entirely by interannual variance in spring precipitation. Greater fluctuations in spring precipitation resulted in higher admixture proportions, likely mediated by the effects of spring precipitation on the expression of traits that determine premating reproductive isolation. Climate-driven hybridization dynamics may be particularly affected by global change, potentially reshaping species boundaries and adaptation to novel environments.
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Affiliation(s)
- Shelley A. Sianta
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN55108
| | - David A. Moeller
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN55108
| | - Yaniv Brandvain
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN55108
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Huang JF, Darwell CT, Peng YQ. Enhanced and asymmetric signatures of hybridization at climatic margins: Evidence from closely related dioecious fig species. PLANT DIVERSITY 2024; 46:181-193. [PMID: 38807912 PMCID: PMC11128846 DOI: 10.1016/j.pld.2023.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 08/17/2023] [Accepted: 08/21/2023] [Indexed: 05/30/2024]
Abstract
Hybridization plays a significant role in biological evolution. However, it is not clear whether ecological contingency differentially influences likelihood of hybridization, particularly at ecological margins where parental species may exhibit reduced fitnesses. Moreover, it is unknown whether future ecosystem change will increase the prevalence of hybridization. Ficus heterostyla and F. squamosa are closely related species co-distributed from southern Thailand to southwest China where hybridization, yielding viable seeds, has been documented. As a robust test of ecological factors driving hybridization, we investigated spatial hybridization signatures based on nuclear microsatellites from extensive population sampling across a widespread contact range. Both species showed high population differentiation and strong patterns of isolation by distance. Admixture estimates exposed asymmetric interspecific gene flow. Signatures of hybridization increase significantly towards higher latitude zones, peaking at the northern climatic margins. Geographic variation in reproductive phenology combined with ecologically challenging marginal habitats may promote this phenomenon. Our work is a first systematic evaluation of such patterns in a comprehensive, latitudinally-based clinal context, and indicates that tendency to hybridize appears strongly influenced by environmental conditions. Moreover, that future climate change scenarios will likely alter and possibly augment cases of hybridization at ecosystem scales.
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Affiliation(s)
- Jian-Feng Huang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China
| | - Clive T. Darwell
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Yan-Qiong Peng
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China
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Indira Cervantes-Díaz C, Patiño-Conde V, González-Rodríguez A, Quesada M, Cuevas E. Molecular and morphological evidence of hybridization between two dimorphic sympatric species of Fuchsia (Onagraceae). AOB PLANTS 2024; 16:plad089. [PMID: 38213511 PMCID: PMC10783250 DOI: 10.1093/aobpla/plad089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 12/16/2023] [Indexed: 01/13/2024]
Abstract
Hybridization is commonly reported in angiosperms, generally based on morphology, and in few cases confirmed by molecular markers. Fuchsia has a long tradition of ornamental cultivars with different hybrids produced by artificial crosses, so natural hybridization between sympatric Fuchsia species could be common. Natural hybridization between F. microphylla and F. thymifolia was tested using six newly developed microsatellites for F. microphylla in addition to other molecular markers with codominant and maternal inheritance. Geometric morphometrics of leaves and floral structures were also used to identify putative hybrids. Hybrids showed a different degree of genetic admixture between both parental species. Chloroplast DNA (cpDNA) sequences indicated that hybridization occurs in both directions, in fact, some of the hybrids showed new haplotypes for cpDNA and ITS (internal transcriber spacer of nuclear ribosomal RNA genes) sequences. The morphology of hybrid individuals varied between the two parental species, but they could be better identified by their leaves and floral tubes. Our study is the first to confirm the hybridization in natural populations of Fuchsia species and suggests that hybridization has probably occurred repeatedly throughout the entire distribution of the species. Phylogeographic analysis of both species will be essential to understanding the impact of hybridization throughout their complete distribution.
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Affiliation(s)
- Cinthya Indira Cervantes-Díaz
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores, Unidad Morelia, Universidad Nacional Autónoma de México, Morelia 58190, Michoacán, México
- Facultad de Biología, Universidad Michoacana de San Nicolás de Hidalgo 58000, Morelia, Michoacán, México
| | - Violeta Patiño-Conde
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores, Unidad Morelia, Universidad Nacional Autónoma de México, Morelia 58190, Michoacán, México
| | - Antonio González-Rodríguez
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia 58190, Michoacán, México
| | - Mauricio Quesada
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores, Unidad Morelia, Universidad Nacional Autónoma de México, Morelia 58190, Michoacán, México
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia 58190, Michoacán, México
| | - Eduardo Cuevas
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores, Unidad Morelia, Universidad Nacional Autónoma de México, Morelia 58190, Michoacán, México
- Facultad de Biología, Universidad Michoacana de San Nicolás de Hidalgo 58000, Morelia, Michoacán, México
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Greaves E, Kron P, Husband BC. Demographic and reproductive impacts of hybridization unrelated to hybrid viability in a native plant. AMERICAN JOURNAL OF BOTANY 2023; 110:e16208. [PMID: 37409880 DOI: 10.1002/ajb2.16208] [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: 12/15/2022] [Revised: 04/28/2023] [Accepted: 05/03/2023] [Indexed: 07/07/2023]
Abstract
PREMISE Introduced species can influence native congeners through production of hybrids and introgression, but impacts not involving viable hybrids, such as reduced conspecific offspring and increased asexual seed production, are rarely examined. Here we tested for these demographic and reproductive consequences of hybridization between introduced, domesticated apple (Malus domestica) and native crabapple (M. coronaria) in southern Canada. METHODS We applied four pollination treatments (open, M. coronaria, M. domestica, open + M. coronaria) to focal M. coronaria trees across multiple years and assessed the number and reproductive origins of resulting seeds (hybrid or conspecific endosperm and, for each, sexual or asexual embryo) using flow cytometry. RESULTS In open-pollinated fruit, 27% of seeds had hybrid endosperm; 52% of embryos were asexual. The number of conspecific embryos (sexual or asexual) per fruit did not decline significantly with increasing hybridization, indicating no seed discounting, but hand pollinations using only domestic apple or crabapple pollen reduced the number of conspecific embryos significantly. Hybridization was not associated with a change in percentage asexual embryos, overall, but there was an increase in asexual embryos in tetraploid seeds, the maternal and most common offspring ploidy. CONCLUSIONS We conclude that hybridization can influence native Malus in ways beyond the production of viable hybrids, with significant implications for population dynamics and genetic structure.
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Affiliation(s)
- Elaina Greaves
- Department of Integrative Biology, University of Guelph, 50 Stone Road E., Guelph, Ontario, N1G 2W1, Canada
| | - Paul Kron
- Department of Integrative Biology, University of Guelph, 50 Stone Road E., Guelph, Ontario, N1G 2W1, Canada
| | - Brian C Husband
- Department of Integrative Biology, University of Guelph, 50 Stone Road E., Guelph, Ontario, N1G 2W1, Canada
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Carnicero P, Kröll J, Schönswetter P. Homoploid hybrids are common but evolutionary dead ends, whereas polyploidy is not linked to hybridization in a group of Pyrenean saxifrages. Mol Phylogenet Evol 2023; 180:107703. [PMID: 36632928 DOI: 10.1016/j.ympev.2023.107703] [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: 10/25/2022] [Revised: 12/28/2022] [Accepted: 01/06/2023] [Indexed: 01/09/2023]
Abstract
Hybridization and polyploidy are major forces in plant evolution. Homoploid hybridization can generate new species via hybrid speciation, or modify extant evolutionary lineages through introgression. Polyploidy enables instantaneous reproductive isolation from the parental lineage(s) and is often coupled with evolutionary innovations, especially when linked to hybridization. While allopolyploidy is a well-known and common mechanism of plant speciation, the evolutionary role of autopolyploidy might have been underestimated. Here, we studied the saxifrages of Saxifraga subsection Saxifraga in the Pyrenees, which easily hybridise and include polyploid populations of uncertain origin, as a model to unravel evolutionary consequences and origin of hybridization and polyploidy. Additionally, we investigate the phylogenetic relationship between the two subspecies of the endemic S. pubescens to ascertain whether they should rather be treated as different species. For these purposes, we combined ploidy-informed restriction associated DNA analyses, plastid DNA sequences and morphological data on a comprehensive population sample of seven species. Our results unravel multiple homoploid hybridization events at the diploid level between different species pairs, but with limited evolutionary impact. The ploidy-informed analyses reveal that all tetraploid populations detected in the present study belong to the widespread alpine species S. moschata. Although of autopolyploid origin, they are to some extent morphologically differentiated and underwent a different evolutionary pathway than their diploid parent. However, the high plastid DNA diversity and the internal structure within eastern and western population groups suggest multiple origins of the polyploids. Finally, our phylogenetic analyses show that S. pubescens and S. iratiana are clearly not sister lineages, and should consequently be considered as independent species.
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Affiliation(s)
- Pau Carnicero
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria.
| | - Joelle Kröll
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Peter Schönswetter
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
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Bitani N, Shivambu TC, Shivambu N, Downs CT. An impact assessment of alien invasive plants in South Africa generally dispersed by native avian species. NEOBIOTA 2022. [DOI: 10.3897/neobiota.74.83342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Invasive alien plant species have been identified as a major threat to biodiversity and the relationship with native avian dispersers may increase their invasion potential. The impact of invasive plant species needs to be quantified using comparable assessment tools across different habitats and species to allocate limited resources to high-priority species. Here, we used the Generic Impact Scoring System (GISS) to assess the impacts of 16 fleshy-fruited alien invasive plant species in South Africa generally dispersed by native avian species. The results showed that fleshy-fruited invasive species have both environmental and socio-economic impacts. The cumulated impact scores for lantana (Lantana camara) and the tree of heaven (Ailanthus altissima) were the highest, with scores of 42 and 32, respectively. Some species, such as white mulberry (Morus alba), camphor tree (Cinnamomum camphora), American bramble (Rubus cuneifolius) and Brazilian pepper tree (Schinus terebinthifolius), had low overall impact scores of 8, 18, 14 and 16, respectively, but scored the maximum impact of 5 for certain mechanisms. Environmental impacts of fleshy-fruited invasive plant species had a high impact magnitude through effects on the ecosystem and vegetation. Socio-economic impacts were mainly through effects on forest production, agriculture and human health. Species with large crop sizes, small seeds and fruit sizes had higher environmental and socio-economic impact magnitude. The information generated in this study is important for guiding resource allocation and preventing the uncontrolled introduction of invasive species in South Africa. The impact of the fleshy-fruited invasive species transcended sectors and, therefore, effective management of invasive species will require the collaboration of multiple and inter-sectoral stakeholders in South Africa.
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Dependence of the Distribution and Structure of the White Mulberry ( Morus alba) Population in Wrocław on the Intensity of Anthropopressure and Thermal Conditions. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19020838. [PMID: 35055660 PMCID: PMC8776231 DOI: 10.3390/ijerph19020838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/05/2022] [Accepted: 01/07/2022] [Indexed: 02/04/2023]
Abstract
The selection of species which show the highest possible tolerance to negative habitat conditions, also among plants of foreign origin, is a pressing issue. One of the species we would like to recommend for planting in urban areas is the white mulberry species (Morus alba) due to both its outstanding adaptability and its ecosystem services. There are no reliable studies on the distribution of this species in urbanized areas in Poland, nor sufficient analyses of the methods of its renewal, both deliberate and spontaneous spread through self-seeding. Collecting data on the population of an alien species within individual regions and forecasting potential changes in the population’s size and structure, as well as its possible impacts on other organisms, is one of the basic measures to reduce biological invasions, which is one of the six priority objectives of the European Biodiversity Strategy and an element of the Strategy on Invasive Alien Species. The aim of this study was to determine the size and structure of the white mulberry population in the city of Wrocław and to analyse the relationship between this structure and intensity of anthropopressure and thermal conditions.
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Marchetti L, Saviane A, Montà AD, Paglia G, Pellati F, Benvenuti S, Bertelli D, Cappellozza S. Determination of 1-Deoxynojirimycin (1-DNJ) in Leaves of Italian or Italy-Adapted Cultivars of Mulberry ( Morus sp.pl.) by HPLC-MS. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10081553. [PMID: 34451598 PMCID: PMC8402161 DOI: 10.3390/plants10081553] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 05/09/2023]
Abstract
Recently, 1-DNJ has been widely studied by scientists for its capacity to inhibit α-glucosidase and reduce postprandial blood glucose and fat accumulation. To the best of our knowledge, this is the first analytical determination of 1-DNJ in Morus sp.pl. leaves carried out on Italian crops, and it could be used as a reference to assess the quality of the plant material in comparison to Far Eastern Asia cultivations. The effects of two thermal treatments were compared to test the incidence of the drying process on the 1-DNJ extractability. In addition, two harvesting seasons in the same year (2017) and two subsequent harvesting years (2017-2018) were considered. The amount of 1-DNJ herein found was comparable to that reported in the scientific literature for Asian cultivations. The increase in 1-DNJ along the summer and the higher level of this compound in the apical leaves also complies with previous findings. However, a strong implication for the climatic conditions in the different years and a significant interaction between climate and genotypes suggest exploring very carefully the agronomic practices and selecting cultivars according to different environmental conditions with a view to standardize the 1-DNJ amount in leaves.
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Affiliation(s)
- Lucia Marchetti
- Department of Life Sciences, University of Modena and Reggio Emilia, Via G. Campi 103, 41125 Modena, Italy; (L.M.); (F.P.); (S.B.)
- Doctorate School in Clinical and Experimental Medicine (CEM), University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Alessio Saviane
- Consiglio per la Ricerca in Agricoltura e L’Analisi Dell’Economia Agraria (CREA)-Centro per la Ricerca Agricoltura e Ambiente, Laboratorio di Gelsibachicoltura, Via Eulero, 6a, 35143 Padova, Italy; (A.S.); (A.d.M.); (G.P.); (S.C.)
| | - Antonella dalla Montà
- Consiglio per la Ricerca in Agricoltura e L’Analisi Dell’Economia Agraria (CREA)-Centro per la Ricerca Agricoltura e Ambiente, Laboratorio di Gelsibachicoltura, Via Eulero, 6a, 35143 Padova, Italy; (A.S.); (A.d.M.); (G.P.); (S.C.)
| | - Graziella Paglia
- Consiglio per la Ricerca in Agricoltura e L’Analisi Dell’Economia Agraria (CREA)-Centro per la Ricerca Agricoltura e Ambiente, Laboratorio di Gelsibachicoltura, Via Eulero, 6a, 35143 Padova, Italy; (A.S.); (A.d.M.); (G.P.); (S.C.)
| | - Federica Pellati
- Department of Life Sciences, University of Modena and Reggio Emilia, Via G. Campi 103, 41125 Modena, Italy; (L.M.); (F.P.); (S.B.)
| | - Stefania Benvenuti
- Department of Life Sciences, University of Modena and Reggio Emilia, Via G. Campi 103, 41125 Modena, Italy; (L.M.); (F.P.); (S.B.)
| | - Davide Bertelli
- Department of Life Sciences, University of Modena and Reggio Emilia, Via G. Campi 103, 41125 Modena, Italy; (L.M.); (F.P.); (S.B.)
- Correspondence: ; Tel.: +39-0592058561
| | - Silvia Cappellozza
- Consiglio per la Ricerca in Agricoltura e L’Analisi Dell’Economia Agraria (CREA)-Centro per la Ricerca Agricoltura e Ambiente, Laboratorio di Gelsibachicoltura, Via Eulero, 6a, 35143 Padova, Italy; (A.S.); (A.d.M.); (G.P.); (S.C.)
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Zaya DN, Leicht-Young SA, Pavlovic NB, Ashley MV. Heterospecific pollination by an invasive congener threatens the native American bittersweet, Celastrus scandens. PLoS One 2021; 16:e0248635. [PMID: 33755682 PMCID: PMC7987179 DOI: 10.1371/journal.pone.0248635] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 03/02/2021] [Indexed: 11/19/2022] Open
Abstract
Invasive plants have the potential to interfere with native species’ reproductive success through a number of mechanisms, including heterospecific pollination and hybridization. This study investigated reproductive interactions between a native North American woody vine (American bittersweet, Celastrus scandens) and an introduced congener (oriental bittersweet, C. orbiculatus). The decline of C. scandens in the eastern portion of its range is coincident with the introduction and spread of C. orbiculatus, and the two species are known to hybridize. The relationship between proximity and floral production of conspecific and heterospecific males on fertilization and hybridization rates was measured at a field site in northwestern Indiana, USA where both species occur and reproduce. We found that the invasive vine had an extreme advantage in both male and female floral production, producing nearly 200 times more flowers per staminate plant and 65 times more flowers per pistillate plant than the native. Using nuclear microsatellite DNA markers we found that hybridization rates were asymmetric; 39% of the C. scandens seeds tested were hybrids, compared to only 1.6% of C. orbiculatus seeds. The asymmetric hybridization rates were likely not solely due to greater abundance of C. orbiculatus pollen because experimental hand crosses revealed that C. scandens had a higher rate (41%) of heterospecific fertilization than C. orbiculatus (2.4%). We previously reported that few hybrids were observed in the wild, and hybrids had greatly reduced fecundity. Thus, in our system, the threat posed by heterospecific pollen is not replacement by hybrids or introgression, but rather asymmetric reproductive interference. Reproductive interference extended to distances as great as 100 meters, thus, efforts to conserve the native species must reduce its exposure to C. orbiculatus over a relatively large spatial scale.
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Affiliation(s)
- David N. Zaya
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
| | - Stacey A. Leicht-Young
- U.S. Geological Survey, Great Lakes Science Center, Chesterton, Indiana, United States of America
| | - Noel B. Pavlovic
- U.S. Geological Survey, Great Lakes Science Center, Chesterton, Indiana, United States of America
| | - Mary V. Ashley
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
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Caeiro-Dias G, Brelsford A, Kaliontzopoulou A, Meneses-Ribeiro M, Crochet PA, Pinho C. Variable levels of introgression between the endangered Podarcis carbonelli and highly divergent congeneric species. Heredity (Edinb) 2021; 126:463-476. [PMID: 33199832 PMCID: PMC8027454 DOI: 10.1038/s41437-020-00386-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 10/27/2020] [Accepted: 10/29/2020] [Indexed: 11/08/2022] Open
Abstract
Recent empirical studies have demonstrated that speciation with gene flow is more common than previously thought. From a conservation perspective, the potential negative effects of hybridization raise concerns on the genetic integrity of endangered species. However, introgressive hybridization has also been growingly recognized as a source of diversity and new advantageous alleles. Carbonell's wall lizard (Podarcis carbonelli) is an endangered species whose distribution overlaps with four other congeneric species. Our goal here was to determine whether P. carbonelli is completely reproductively isolated from its congeners and to evaluate the relevance of hybridization and interspecific gene flow for developing a conservation plan. We used restriction site associated DNA (RAD) sequencing to discover SNPs in samples from four contact zones between P. carbonelli and four other species. Principal component analysis, multilocus genotype assignment and interspecific heterozygosity suggest incomplete reproductive isolation and ongoing gene flow between species. However, hybridization dynamics vary across all pairs, suggesting complex interactions between multiple intrinsic and extrinsic barriers. Despite seemingly ubiquitous interspecific gene flow, we found evidence of strong reproductive isolation across most contact zones. Instead, indirect effects of hybridization like waste of reproductive effort in small isolated populations may be more problematic. Our results highlight the need to further evaluate the consequences of introgression for P. carbonelli, both on a geographic and genomic level and included in a comprehensive and urgently needed conservation plan. Besides, those findings will add important insights on the potential effects of hybridization and introgression for endangered species.
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Affiliation(s)
- Guilherme Caeiro-Dias
- Centro de Investigação em Biodiversidade e Recursos Genéticos, CIBIO/InBIO, Universidade do Porto, Vairão, Portugal.
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal.
- CEFE, CNRS, Université de Montpellier, EPHE, IRD, Université Paul Valéry Montpellier 3, Montpellier, France.
| | - Alan Brelsford
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Biology Department, University of California Riverside, Riverside, CA, USA
| | - Antigoni Kaliontzopoulou
- Centro de Investigação em Biodiversidade e Recursos Genéticos, CIBIO/InBIO, Universidade do Porto, Vairão, Portugal
| | - Mariana Meneses-Ribeiro
- Centro de Investigação em Biodiversidade e Recursos Genéticos, CIBIO/InBIO, Universidade do Porto, Vairão, Portugal
| | - Pierre-André Crochet
- CEFE, CNRS, Université de Montpellier, EPHE, IRD, Université Paul Valéry Montpellier 3, Montpellier, France
| | - Catarina Pinho
- Centro de Investigação em Biodiversidade e Recursos Genéticos, CIBIO/InBIO, Universidade do Porto, Vairão, Portugal
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13
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Dong CM, Rankin KJ, McLean CA, Stuart-Fox D. Maternal reproductive output and F1 hybrid fitness may influence contact zone dynamics. J Evol Biol 2021; 34:680-694. [PMID: 33580546 DOI: 10.1111/jeb.13772] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 01/31/2021] [Accepted: 02/01/2021] [Indexed: 12/19/2022]
Abstract
The outcome of secondary contact between divergent lineages or species may be influenced by both the reproductive traits of parental species and the fitness of offspring; however, their relative contributions have rarely been evaluated, particularly in longer-lived vertebrate species. We performed pure and reciprocal laboratory crosses between Ctenophorus decresii (tawny dragon) and C. modestus (swift dragon) to examine how parental reproductive traits and ecologically relevant offspring fitness traits may explain contact zone dynamics in the wild. The two species meet in a contact zone of post-F1 hybrids with asymmetric backcrossing and predominantly C. modestus mtDNA haplotypes. We found no evidence for reduced parental fecundity or offspring fitness for F1 hybrid crosses. However, maternal reproductive strategy differed between species, irrespective of the species of their mate. Ctenophorus modestus females had higher fecundity and produced more and larger clutches with lower embryonic mortality. Parental species also influenced sex ratios and offspring traits, with C. modestus ♀ × C. decresii ♂ hybrids exhibiting higher trait values for more fitness measures (growth rate, sprint speed, bite force) than offspring from all other pairings. Together, these patterns are consistent with the prevalence of C. modestus mtDNA in the contact zone, and asymmetric backcrossing likely reflects fitness effects that manifest in the F2 generation. Our results highlight how parental species can influence multiple offspring traits in different ways, which together may combine to influence offspring fitness and shape contact zone dynamics.
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Affiliation(s)
- Caroline M Dong
- School of BioSciences, The University of Melbourne, Parkville, Vic., Australia.,Sciences Department, Museums Victoria, Melbourne, Vic., Australia
| | - Katrina J Rankin
- School of BioSciences, The University of Melbourne, Parkville, Vic., Australia
| | - Claire A McLean
- School of BioSciences, The University of Melbourne, Parkville, Vic., Australia.,Sciences Department, Museums Victoria, Melbourne, Vic., Australia
| | - Devi Stuart-Fox
- School of BioSciences, The University of Melbourne, Parkville, Vic., Australia
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14
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Maxwell LM, Walsh J, Olsen BJ, Kovach AI. Patterns of introgression vary within an avian hybrid zone. BMC Ecol Evol 2021; 21:14. [PMID: 33509089 PMCID: PMC7853311 DOI: 10.1186/s12862-021-01749-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 01/20/2021] [Indexed: 12/29/2022] Open
Abstract
Background Exploring hybrid zone dynamics at different spatial scales allows for better understanding of local factors that influence hybrid zone structure. In this study, we tested hypotheses about drivers of introgression at two spatial scales within the Saltmarsh Sparrow (Ammospiza caudacuta) and Nelson’s Sparrow (A. nelsoni) hybrid zone. Specifically, we evaluated the influence of neutral demographic processes (relative species abundance), natural selection (exogenous environmental factors and genetic incompatibilities), and sexual selection (assortative mating) in this mosaic hybrid zone. By intensively sampling adults (n = 218) and chicks (n = 326) at two geographically proximate locations in the center of the hybrid zone, we determined patterns of introgression on a fine scale across sites of differing habitat. We made broadscale comparisons of patterns from the center with those of prior studies in the southern edge of the hybrid zone. Results A panel of fixed SNPs (135) identified from ddRAD sequencing was used to calculate a hybrid index and determine genotypic composition/admixture level of the populations. Another panel of polymorphic SNPs (589) was used to assign paternity and reconstruct mating pairs to test for sexual selection. On a broad-scale, patterns of introgression were not explained by random mating within marshes. We found high rates of back-crossing and similarly low rates of recent-generation (F1/F2) hybrids in the center and south of the zone. Offspring genotypic proportions did not meet those expected from random mating within the parental genotypic distribution. Additionally, we observed half as many F1/F2 hybrid female adults than nestlings, while respective male groups showed no difference, in support of Haldane’s Rule. The observed proportion of interspecific mating was lower than expected when accounting for mate availability, indicating assortative mating was limiting widespread hybridization. On a fine spatial scale, we found variation in the relative influence of neutral and selective forces between inland and coastal habitats, with the smaller, inland marsh influenced primarily by neutral demographic processes, and the expansive, coastal marsh experiencing higher selective pressures in the form of natural (exogenous and endogenous) and sexual selection. Conclusions Multiple drivers of introgression, including neutral and selective pressures (exogenous, endogenous, and sexual selection), are structuring this hybrid zone, and their relative influence is site and context-dependent.
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Affiliation(s)
- Logan M Maxwell
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, USA
| | - Jennifer Walsh
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, USA.,Fuller Evolutionary Biology Program, Cornell Laboratory of Ornithology, Ithaca, NY, 14850, USA
| | - Brian J Olsen
- School of Biology & Ecology, University of Maine, Orono, ME, USA
| | - Adrienne I Kovach
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, USA.
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15
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Ostevik KL, Rifkin JL, Xia H, Rausher MD. Morning glory species co-occurrence is associated with asymmetrically decreased and cascading reproductive isolation. Evol Lett 2020; 5:75-85. [PMID: 33552537 PMCID: PMC7857285 DOI: 10.1002/evl3.205] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 10/04/2020] [Accepted: 10/19/2020] [Indexed: 01/25/2023] Open
Abstract
Hybridization between species can affect the strength of the reproductive barriers that separate those species. Two extensions of this effect are (1) the expectation that asymmetric hybridization or gene flow will have asymmetric effects on reproductive barrier strength and (2) the expectation that local hybridization will affect only local reproductive barrier strength and could therefore alter within‐species compatibility. We tested these hypotheses in a pair of morning glory species that exhibit asymmetric gene flow from highly selfing Ipomoea lacunosa into mixed‐mating Ipomoea cordatotriloba in regions where they co‐occur. Because of the direction of this gene flow, we predicted that reproductive barrier strength would be more strongly affected in I. cordatotriloba than I. lacunosa. We also predicted that changes to reproductive barriers in sympatric I. cordatotriloba populations would affect compatibility with allopatric populations of that species. We tested these predictions by measuring the strength of a reproductive barrier to seed set across the species’ ranges. Consistent with our first prediction, we found that sympatric and allopatric I. lacunosa produce the same number of seeds in crosses with I. cordatotriloba, whereas crosses between sympatric I. cordatotriloba and I. lacunosa are more successful than crosses between allopatric I. cordatotriloba and I. lacunosa. This difference in compatibility appears to reflect an asymmetric decrease in the strength of the barrier to seed set in sympatric I. cordatotriloba, which could be caused by I. lacunosa alleles that have introgressed into I. cordatotriloba. We further demonstrated that changes to sympatric I. cordatotriloba have decreased its ability to produce seeds with allopatric populations of the same species, in line with our second prediction. Thus, in a manner analogous to cascade reinforcement, we suggest that introgression associated with hybridization not only influences between‐species isolation but can also contribute to isolation within a species.
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Affiliation(s)
- Kate L Ostevik
- Department of Biology Duke University Durham North Carolina 27708
| | - Joanna L Rifkin
- Department of Ecology and Evolutionary Biology University of Toronto Toronto ON M5S 3B2 Canada
| | - Hanhan Xia
- College of Horticulture and Landscape Architecture Zhongkai University of Agriculture and Engineering Guangzhou 510225 China
| | - Mark D Rausher
- Department of Biology Duke University Durham North Carolina 27708
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16
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Cheng J, Zhang N, Sha Z. Nuclear microsatellites reveal population genetic structuring and fine-scale pattern of hybridization in the Japanese mantis shrimp Oratosquilla oratoria. PeerJ 2020; 8:e10270. [PMID: 33194430 PMCID: PMC7649012 DOI: 10.7717/peerj.10270] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 10/08/2020] [Indexed: 11/27/2022] Open
Abstract
The interplay between historical and contemporary processes can produce complex patterns of genetic differentiation in the marine realm. Recent mitochondrial and nuclear sequence analyses revealed cryptic speciation in the Japanese mantis shrimp Oratosquilla oratoria. Herein, we applied nuclear microsatellite markers to examine patterns and causes of genetic differentiation in this morphotaxon. Population structure analyses revealed two genetically divergent and geographically structured clades in O. oratoria, one dominating the temperate zone of the Northwestern (NW) Pacific and the other occurring in the subtropical and tropical waters where are influenced by the Kuroshio Current. Two sympatric zones, one around the Changjiang Estuary in China coast and the other in the northern Japan Sea, were demonstrated to be hybrid zones where introgressive hybridization occurred asymmetrically. The interaction between historical climate shifts and contemporary factors (e.g., freshwater discharge, temperature gradient and isolation by distance) may contribute to the present-day genetic architecture in the Japanese mantis shrimp. Range shift induced by climate changes and oceanographic factors may promote hybridization and gene flow between the O. oratoria complex. Our results provide insights into the interacting mechanisms that give rise to diversification and speciation of coastal species in the NW Pacific.
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Affiliation(s)
- Jiao Cheng
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Nan Zhang
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Zhongli Sha
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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17
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Tisshaw K, Freeland J, Dorken M. Salinity, not genetic incompatibilities, limits the establishment of the invasive hybrid cattail Typha × glauca in coastal wetlands. Ecol Evol 2020; 10:12091-12103. [PMID: 33209272 PMCID: PMC7663983 DOI: 10.1002/ece3.6831] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/31/2020] [Accepted: 09/03/2020] [Indexed: 11/08/2022] Open
Abstract
Hybrids of a single pair of parent species can be much more common in some geographical regions than in others. The reasons for this are not well understood, but could help explain processes such as species diversification or the range expansion of invasive hybrids. The widespread cattails Typha latifolia and T. angustifolia seldom hybridize in some parts of their range, but in other areas produce the dominant hybrid T. × glauca. We used a combination of field and greenhouse experiments to investigate why T. × glauca has invaded wetlands in the Laurentian Great Lakes region of southern Ontario, Canada, but is much less common in the coastal wetlands of Nova Scotia (NS) in eastern Canada. One potentially important environmental difference between these two regions is salinity. We therefore tested three hypotheses: (1) T. latifolia and T. angustifolia in NS are genetically incompatible; (2) the germination or growth of T. × glauca is reduced by salinity; and (3) T. latifolia, a main competitor of T. × glauca, is locally adapted to saline conditions in NS. Our experiments showed that NS T. latifolia and T. angustifolia are genetically compatible, and that saline conditions do not impede growth of hybrid plants. However, we also found that under conditions of high salinity, germination rates of hybrid seeds were substantially lower than those of NS T. latifolia. In addition, germination rates of NS T. latifolia were higher than those of Ontario T. latifolia, suggesting local adaptation to salinity in coastal wetlands. This study adds to the growing body of literature which identifies the important roles that local habitat and adaptation can play in the distributions and characteristics of hybrid zones.
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Affiliation(s)
- Kathryn Tisshaw
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughONCanada
| | - Joanna Freeland
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughONCanada
- Department of BiologyTrent UniversityPeterboroughONCanada
| | - Marcel Dorken
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughONCanada
- Department of BiologyTrent UniversityPeterboroughONCanada
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18
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Xuan Y, Wu Y, Li P, Liu R, Luo Y, Yuan J, Xiang Z, He N. Molecular phylogeny of mulberries reconstructed from ITS and two cpDNA sequences. PeerJ 2019; 7:e8158. [PMID: 31844573 PMCID: PMC6911693 DOI: 10.7717/peerj.8158] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 11/04/2019] [Indexed: 11/20/2022] Open
Abstract
Background Species in the genus Morus (Moraceae) are deciduous woody plants of great economic importance. The classification and phylogenetic relationships of Morus, especially the abundant mulberry resources in China, is still undetermined. Internal transcribed spacer (ITS) regions are among the most widely used molecular markers in phylogenetic analyses of angiosperms. However, according to the previous phylogenetic analyses of ITS sequences, most of the mulberry accessions collected in China were grouped into the largest clade lacking for phylogenetic resolution. Compared with functional ITS sequences, ITS pseudogenes show higher sequence diversity, so they can provide useful phylogenetic information. Methods We sequenced the ITS regions and the chloroplast DNA regions TrnL-TrnF and TrnT-TrnL from 33 mulberry accessions, and performed phylogenetic analyses to explore the evolution of mulberry. Results We found ITS pseudogenes in 11 mulberry accessions. In the phylogenetic tree constructed from ITS sequences, clade B was separated into short-type sequence clades (clades 1 and 2), and a long-type sequence clade (clade 3). Pseudogene sequences were separately clustered into two pseudogroups, designated as pseudogroup 1 and pseudogroup 2. The phylogenetic tree generated from cpDNA sequences also separated clade B into two clades. Conclusions Two species were separated in clade B. The existence of three connection patterns and incongruent distribution patterns between the phylogenetic trees generated from cpDNA and ITS sequences suggested that the ITS pseudogene sequences connect with genetic information from the female progenitor. Hybridization has played important roles in the evolution of mulberry, resulting in low resolution of the phylogenetic analysis based on ITS sequences. An evolutionary pattern illustrating the evolution history of mulberry is proposed. These findings have significance for the conservation of local mulberry resources. Polyploidy, hybridization, and concerted evolution have all played the roles in the evolution of ITS sequences in mulberry. This study will expand our understanding of mulberry evolution.
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Affiliation(s)
- Yahui Xuan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Yue Wu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Peng Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Ruiling Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Yiwei Luo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Jianglian Yuan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Zhonghuai Xiang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Ningjia He
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
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19
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Nieto Feliner G, Rosato M, Alegre G, San Segundo P, Rosselló JA, Garnatje T, Garcia S. Dissimilar molecular and morphological patterns in an introgressed peripheral population of a sand dune species (Armeria pungens, Plumbaginaceae). PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:1072-1082. [PMID: 31349366 DOI: 10.1111/plb.13035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 07/23/2019] [Indexed: 05/26/2023]
Abstract
Introgression is a poorly understood evolutionary outcome of hybridisation because it may remain largely undetected whenever it involves the transfer of small parts of the genome from one species to another. Aiming to understand the early stages of this process, a putative case from the southernmost border of the Armeria pungens range from its congener A. macrophylla is revisited following the discovery of a subpopulation that does not show phenotypic signs of introgression and resembles typical A. pungens. We analysed morphometrics, nuclear ribosomal DNA ITS and plastid DNA (trnL-trnF) sequences, genome size, 45S and 5S rDNA loci-FISH data and nrDNA IGS sequences. Within the study site, most individuals match morphologies of either of the two hybridising species, particularly the new subpopulation, with intermediate phenotypes being scarce. This pattern does not fully fit molecular evidence revealing two ITS ribotypes co-occurring intragenomically in most plants from the study site and one single plastid haplotype. Genome size and structural features of the IGS sequences both indicate that A. pungens from the study site is genetically more similar to its sympatric congener than to the remainder of its conspecifics. Introgression of A. macrophylla into A. pungens and plastid capture explain all the evidence analysed. However, important features to understand the origin and fate of the introgressed population, such as the degree and direction of introgression, which are important for understanding early stages of hybridisation in plants with low reproductive barriers, should be addressed with new data.
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Affiliation(s)
| | - M Rosato
- Jardín Botánico, ICBIBE-Unidad Asociada CSIC, Universidad de Valencia, Valencia, Spain
| | - G Alegre
- Institut Botànic de Barcelona (IBB-CSIC-ICUB), Barcelona, Catalonia, Spain
| | | | - J A Rosselló
- Jardín Botánico, ICBIBE-Unidad Asociada CSIC, Universidad de Valencia, Valencia, Spain
| | - T Garnatje
- Institut Botànic de Barcelona (IBB-CSIC-ICUB), Barcelona, Catalonia, Spain
| | - S Garcia
- Institut Botànic de Barcelona (IBB-CSIC-ICUB), Barcelona, Catalonia, Spain
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20
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Hu YN, Zhao L, Buggs RJA, Zhang XM, Li J, Wang N. Population structure of Betula albosinensis and Betula platyphylla: evidence for hybridization and a cryptic lineage. ANNALS OF BOTANY 2019; 123:1179-1189. [PMID: 30916314 PMCID: PMC6612935 DOI: 10.1093/aob/mcz024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/15/2019] [Accepted: 02/05/2019] [Indexed: 05/20/2023]
Abstract
BACKGROUND AND AIMS Differences in local abundance and ploidy level are predicted to impact the direction of introgression between species. Here, we tested these hypotheses on populations of Betula albosinensis (red birch) and Betula platyphylla (white birch) which were thought to differ in ploidy level, the former being tetraploid and the latter diploid. METHODS We sampled 391 birch individuals from nine localities in China, and classified them into species based on leaf morphology. Twelve nuclear microsatellite markers were genotyped in each sample, and analysed using principal coordinates analysis and STRUCTURE software. We compared the effects of two different methods of scoring polyploid genotypes on population genetic analyses. We analysed the effect of ploidy, local species abundance and latitude on levels of introgression between the species. KEY RESULTS Leaf morphology divided our samples into red and white birch, but genetic analyses unexpectedly revealed two groups within red birch, one of which was tetraploid, as expected, but the other of which appeared to have diploid microsatellite genotypes. Five individuals were identified as early-generation hybrids or backcrosses between white birch and red birch and five were identified between red birch and 'diploid' red birch. Cline analysis showed that levels of admixture were not significantly correlated with latitude. Estimated genetic differentiation among species was not significantly different between determined tetraploid and undetermined tetraploid genotypes. CONCLUSIONS Limited hybridization and gene flow have occurred between red birch and white birch. Relative species abundance and ploidy level do not impact the direction of introgression between them, as genetic admixture is roughly symmetrical. We unexpectedly found populations of apparently diploid red birch and this taxon may be a progenitor of allotetraploid red birch populations. Incomplete lineage sorting may explain patterns of genetic admixture between apparently diploid and allotetraploid red birch.
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Affiliation(s)
- Ya-Nan Hu
- College of Forestry, Shandong Agricultural University, Tai’an city, Shandong province, China
| | - Lei Zhao
- Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
| | - Richard J A Buggs
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, UK
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Xue-Min Zhang
- Mulan-Weichang National Forestry Administration, Chengde, China
| | - Jun Li
- Mulan-Weichang National Forestry Administration, Chengde, China
| | - Nian Wang
- College of Forestry, Shandong Agricultural University, Tai’an city, Shandong province, China
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21
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Mota MR, Pinheiro F, Leal BSS, Wendt T, Palma-Silva C. The role of hybridization and introgression in maintaining species integrity and cohesion in naturally isolated inselberg bromeliad populations. PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:122-132. [PMID: 30195257 DOI: 10.1111/plb.12909] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 09/06/2018] [Indexed: 05/02/2023]
Abstract
Hybridization is a widespread phenomenon present in numerous lineages across the tree of life. Its evolutionary consequences range from effects on the origin and maintenance, to the loss of biodiversity. We studied genetic diversity and intra- and interspecific gene flow between two sympatric populations of closely-related species, Pitcairnia flammea and P. corcovadensis (Bromeliaceae), which are adapted to naturally fragmented Neotropical inselbergs, based on nuclear and plastidial DNA. Our main results indicate a strong reproductive isolation barrier, although low levels of interspecific gene flow were observed in both sympatric populations. The low rates of intraspecific gene flow observed for both P. corcovadensis and P. flammea populations corroborate the increasing body of evidence that inselberg bromeliad species are maintained as discrete evolutionary units despite the presence of low genetic connectivity. Nuclear patterns of genetic diversity and gene flow revealed that hybridization and introgression might not cause species extinction via genetic assimilation of the rare P. corcovadensis. In the face of reduced intraspecific gene exchange, hybridization and introgression may be important aspects of the Pitcairnia diversification process, with a positive evolutionary impact at the bromeliad community level, and thus contribute to increasing and maintaining genetic diversity in local isolated inselberg populations.
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Affiliation(s)
- M R Mota
- Departamento de Ecologia, Instituto de Biociências, Universidade Estadual Paulista, Rio Claro, Brazil
| | - F Pinheiro
- Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil
| | - B S S Leal
- Departamento de Ecologia, Instituto de Biociências, Universidade Estadual Paulista, Rio Claro, Brazil
| | - T Wendt
- Departamento de Botânica, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - C Palma-Silva
- Departamento de Ecologia, Instituto de Biociências, Universidade Estadual Paulista, Rio Claro, Brazil
- Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil
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22
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Macková L, Vít P, Urfus T. Crop-to-wild hybridization in cherries-Empirical evidence from Prunus fruticosa. Evol Appl 2018; 11:1748-1759. [PMID: 30344640 PMCID: PMC6183504 DOI: 10.1111/eva.12677] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 06/14/2018] [Accepted: 06/19/2018] [Indexed: 12/25/2022] Open
Abstract
Crop cultivation can lead to genetic swamping of indigenous species and thus pose a serious threat for biodiversity. The rare Eurasian tetraploid shrub Prunus fruticosa (ground cherry) is suspected of hybridizing with cultivated allochthonous tetraploid P. cerasus and autochthonous diploid P. avium. Three Prunus taxa (447 individuals of P. fruticosa, 43 of P. cerasus and 73 of P. avium) and their hybrids (198 individuals) were evaluated using analysis of absolute genome size/ploidy level and multivariate morphometrics. Flow cytometry revealed considerable differentiation in absolute genome size at the tetraploid level (average 2C of P. fruticosa = 1.30 pg, average 2C of P. cerasus = 1.42 pg, i.e., a 9.2% difference). The combination of methods used allowed us to ascertain the frequency of hybrids occurring under natural conditions in Central Europe. The morphological evaluation of leaves was based upon distance-based morphometrics supplemented by elliptic Fourier analysis. The results provided substantial evidence for ongoing hybridization (hybrids occurred in 39.5% of P. fruticosa populations). We detected homoploid introgressive hybridization with alien P. cerasus at the tetraploid level. We also found previously overlooked but frequent triploid hybrids resulting from heteroploid hybridization with indigenous P. avium, which, however, probably represent only the F1 generation. Although both hybrids differ in ploidy, they cannot be distinguished using morphometrics. Hybrids are frequent and may endanger wild populations of genuine P. fruticosa via direct niche competition or, alternatively or in addition, via introgression at the homoploid level (i.e., genetic swamping). The cultivation of cherries thus substantially threatens the existence of genuine P. fruticosa.
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Affiliation(s)
- Lenka Macková
- Department of BotanyFaculty of ScienceCharles UniversityPragueCzech Republic
| | - Petr Vít
- Institute of BotanyThe Czech Academy of SciencesPrůhoniceCzech Republic
- Faculty of Environmental SciencesCzech University of Life Sciences PraguePragueCzech Republic
| | - Tomáš Urfus
- Department of BotanyFaculty of ScienceCharles UniversityPragueCzech Republic
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Roberts WR, Roalson EH. Phylogenomic analyses reveal extensive gene flow within the magic flowers (Achimenes). AMERICAN JOURNAL OF BOTANY 2018; 105:726-740. [PMID: 29702729 DOI: 10.1002/ajb2.1058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 02/02/2018] [Indexed: 06/08/2023]
Abstract
PREMISE OF THE STUDY The Neotropical Gesneriaceae is a lineage known for its colorful and diverse flowers, as well as an extensive history of intra- and intergeneric hybridization, particularly among Achimenes (the magic flowers) and other members of subtribe Gloxiniinae. Despite numerous studies seeking to elucidate the evolutionary relationships of these lineages, relatively few have sought to infer specific patterns of gene flow despite evidence of widespread hybridization. METHODS To explore the utility of phylogenomic data for reassessing phylogenetic relationships and inferring patterns of gene flow among species of Achimenes, we sequenced 12 transcriptomes. We used a variety of methods to infer the species tree, examine gene tree discordance, and infer patterns of gene flow. KEY RESULTS Phylogenomic analyses resolve clade relationships at the crown of the lineage with strong support. In contrast to previous analyses, we recovered strong support for several new relationships despite a significant amount of gene tree discordance. We present evidence for at least two introgression events between two species pairs that share pollinators, and suggest that the species status of Achimenes admirabilis be reexamined. CONCLUSIONS Our study demonstrates the utility of transcriptome data for phylogenomic analyses, and inferring patterns of gene flow despite gene tree discordance. Moreover, these data provide another example of prevalent interspecific gene flow among Neotropical plants that share pollinators.
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Affiliation(s)
- Wade R Roberts
- Molecular Plant Sciences Graduate Program, Washington State University, Pullman, Washington, 99164-1030, USA
- School of Biological Sciences, Washington State University, Pullman, Washington, 99164-4236, USA
| | - Eric H Roalson
- Molecular Plant Sciences Graduate Program, Washington State University, Pullman, Washington, 99164-1030, USA
- School of Biological Sciences, Washington State University, Pullman, Washington, 99164-4236, USA
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Duckworth RA, Semenov GA. Hybridization Associated with Cycles of Ecological Succession in a Passerine Bird. Am Nat 2017; 190:E94-E105. [DOI: 10.1086/693160] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Herklotz V, Ritz CM. Multiple and asymmetrical origin of polyploid dog rose hybrids (Rosa L. sect. Caninae (DC.) Ser.) involving unreduced gametes. ANNALS OF BOTANY 2017; 120:209-220. [PMID: 28028016 PMCID: PMC5737388 DOI: 10.1093/aob/mcw217] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 09/14/2016] [Indexed: 05/18/2023]
Abstract
BACKGROUND AND AIMS Polyploidy and hybridization are important factors for generating diversity in plants. The species-rich dog roses ( Rosa sect. Caninae ) originated by allopolyploidy and are characterized by unbalanced meiosis producing polyploid egg cells (usually 4 x ) and haploid sperm cells (1 x ). In extant natural stands species hybridize spontaneously, but the extent of natural hybridization is unknown. The aim of the study was to document the frequency of reciprocal hybridization between the subsections Rubigineae and Caninae with special reference to the contribution of unreduced egg cells (5 x ) producing 6 x offspring after fertilization with reduced (1 x ) sperm cells. We tested whether hybrids arose by independent multiple events or via a single or few incidences followed by a subsequent spread of hybrids. METHODS Population genetics of 45 mixed stands of dog roses across central and south-eastern Europe were analysed using microsatellite markers and flow cytometry. Hybrids were recognized by the presence of diagnostic alleles and multivariate statistics were used to display the relationships between parental species and hybrids. KEY RESULTS Among plants classified to subsect. Rubigineae , 32 % hybridogenic individuals were detected but only 8 % hybrids were found in plants assigned to subsect. Caninae . This bias between reciprocal crossings was accompanied by a higher ploidy level in Rubigineae hybrids, which originated more frequently by unreduced egg cells. Genetic patterns of hybrids were strongly geographically structured, supporting their independent origin. CONCLUSIONS The biased crossing barriers between subsections are explained by the facilitated production of unreduced gametes in subsect. Rubigineae . Unreduced egg cells probably provide the highly homologous chromosome sets required for correct chromosome pairing in hybrids. Furthermore, the higher frequency of Rubigineae hybrids is probably influenced by abundance effects because the plants of subsect. Caninae are much more abundant and thus provide large quantities of pollen. Hybrids are formed spontaneously, leading to highly diverse mixed stands, which are insufficiently characterized by the actual taxonomy.
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Affiliation(s)
- V. Herklotz
- Department of Botany, Senckenberg Museum of Natural History Görlitz, Am Museum 1, D-02826 Görlitz, Germany
| | - C. M. Ritz
- Department of Botany, Senckenberg Museum of Natural History Görlitz, Am Museum 1, D-02826 Görlitz, Germany
- For correspondence. E-mail
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Genetic Diversity in Relict and Fragmented Populations of Ulmus glabra Hudson in the Central System of the Iberian Peninsula. FORESTS 2017. [DOI: 10.3390/f8050143] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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de Lafontaine G, Bousquet J. Asymmetry matters: A genomic assessment of directional biases in gene flow between hybridizing spruces. Ecol Evol 2017; 7:3883-3893. [PMID: 28616185 PMCID: PMC5468134 DOI: 10.1002/ece3.2682] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 11/16/2016] [Accepted: 11/20/2016] [Indexed: 01/08/2023] Open
Abstract
Assessing directional bias in interspecific gene flow might be important in determining the evolutionary trajectory of closely related species pairs. Using a set of 300 single nucleotide polymorphisms (SNPs) having variable propensity to cross species boundary, we evaluated the genomic extent and direction of interspecific gene flow in a progenitor‐derivative spruce species pair (black spruce and red spruce). A higher rate of gene flow was found from black spruce toward red spruce purebreds than vice versa. This asymmetry could reflect the historical gene flow between the two taxa at the time of species inception and during postglacial colonization. A clear asymmetry in introgression was depicted by a greater gene flow between red spruce and hybrids than between black spruce and hybrids. While backcrossing toward red spruce was invariably high across the genome, the actual species boundary is between hybrids and black spruce where gene flow is impeded at those genomic regions impermeable to introgression. Associations between hybrid index and climatic variables (total annual precipitation and mean annual temperature) were tested, as these might indicate a role for exogenous selection in maintaining the species boundary. While an apparent association was found between the hybrid index and precipitation, it collapsed when considered in light of the directional bias in interspecific gene flow. Hence, considering asymmetrical patterns of introgression allowed us to falsify an apparent role for exogenous selection. Although this was not formerly tested here, we suggest that this pattern could result from asymmetrical endogenous selection, a contention that deserves further investigations.
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Affiliation(s)
- Guillaume de Lafontaine
- Canada Research Chair in Forest Genomics Centre for Forest Research and Institute of Systems and Integrative Biology Université Laval Québec QC Canada.,Department of Plant Biology University of Illinois Urbana IL USA
| | - Jean Bousquet
- Canada Research Chair in Forest Genomics Centre for Forest Research and Institute of Systems and Integrative Biology Université Laval Québec QC Canada
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Bog M, Bässler C, Oberprieler C. Lost in the hybridisation vortex: high-elevation Senecio hercynicus (Compositae, Senecioneae) is genetically swamped by its congener S. ovatus in the Bavarian Forest National Park (SE Germany). Evol Ecol 2017. [DOI: 10.1007/s10682-017-9890-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Campbell LG, Shukla K, Sneck ME, Chaplin C, Mercer KL. The Effect of Altered Soil Moisture on Hybridization Rate in a Crop-Wild System (Raphanus spp.). PLoS One 2016; 11:e0166802. [PMID: 27936159 PMCID: PMC5147839 DOI: 10.1371/journal.pone.0166802] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 11/03/2016] [Indexed: 11/18/2022] Open
Abstract
Since plant mating choices are flexible and responsive to the environment, rates of spontaneous hybridization may vary across ecological clines. Developing a robust and predictive framework for rates of plant gene flow requires assessing the role of environmental sensitivity on plant reproductive traits, relative abundance, and pollen vectors. Therefore, across a soil moisture gradient, we quantified pollinator movement, life-history trait variation, and unidirectional hybridization rates from crop (Raphanus sativus) to wild (Raphanus raphanistrum) radish populations. Both radish species were grown together in relatively dry (no rain), relatively wet (double rain), or control soil moisture conditions in Ohio, USA. We measured wild and crop radish life-history, phenology and pollinator visitation patterns. To quantify hybridization rates from crop-to-wild species, we used a simply inherited morphological marker to detect F1 hybrid progeny. Although crop-to-wild hybridization did not respond to watering treatments, the abundance of hybrid offspring was higher in fruits produced late in the period of phenological overlap, when both species had roughly equal numbers of open flowers. Therefore, the timing of fruit production and its relationship to flowering overlap may be more important to hybrid zone formation in Raphanus spp. than soil moisture or pollen vector movements.
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Affiliation(s)
- Lesley G. Campbell
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
- Department of Biosciences, Rice University, Houston, Texas, United States of America
| | - Kruti Shukla
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
| | - Michelle E. Sneck
- Department of Biosciences, Rice University, Houston, Texas, United States of America
| | - Colleen Chaplin
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
| | - Kristin L. Mercer
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio, United States of America
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Crystal PA, Lichti NI, Woeste KE, Jacobs DF. Vegetative and Adaptive Traits Predict Different Outcomes for Restoration Using Hybrids. FRONTIERS IN PLANT SCIENCE 2016; 7:1741. [PMID: 27920788 PMCID: PMC5118422 DOI: 10.3389/fpls.2016.01741] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 11/04/2016] [Indexed: 05/22/2023]
Abstract
Hybridization has been implicated as a driver of speciation, extinction, and invasiveness, but can also provide resistant breeding stock following epidemics. However, evaluating the appropriateness of hybrids for use in restoration programs is difficult. Past the F1 generation, the proportion of a progenitor's genome can vary widely, as can the combinations of parental genomes. Detailed genetic analysis can reveal this information, but cannot expose phenotypic alterations due to heterosis, transgressive traits, or changes in metabolism or development. In addition, because evolution is often driven by extreme individuals, decisions based on phenotypic averages of hybrid classes may have unintended results. We demonstrate a strategy to evaluate hybrids for use in restoration by visualizing hybrid phenotypes across selected groups of traits relative to both progenitor species. Specifically, we used discriminant analysis to differentiate among butternut (Juglans cinerea L.), black walnut (J. nigra L.), and Japanese walnut (J. ailantifolia Carr. var. cordiformis) using vegetative characters and then with functional adaptive traits associated with seedling performance. When projected onto the progenitor trait space, naturally occurring hybrids (J. × bixbyi Rehd.) between butternut and Japanese walnut showed introgression toward Japanese walnut at vegetative characters but exhibited a hybrid swarm at functional traits. Both results indicate that hybrids have morphological and ecological phenotypes that distinguish them from butternut, demonstrating a lack of ecological equivalency that should not be carried into restoration breeding efforts. Despite these discrepancies, some hybrids were projected into the space occupied by butternut seedlings' 95% confidence ellipse, signifying that some hybrids were similar at the measured traits. Determining how to consistently identify these individuals is imperative for future breeding and species restoration efforts involving hybrids. Discriminant analysis provides a useful technique to visualize past selection mechanisms and current variation in hybrid populations, especially when key ecological traits that distinguish progenitors are unknown. Furthermore, discriminant analysis affords a tool to assess ecological equivalency of hybrid populations and breeding program efforts to select for certain traits and monitor the amount of variability of those traits, relative to progenitors.
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Affiliation(s)
- Philip A. Crystal
- Hardwood Tree Improvement and Regeneration Center, Department of Forestry and Natural Resources, Purdue UniversityWest Lafayette, IN, USA
- Department of Biology, Colby CollegeWaterville, ME, USA
| | - Nathanael I. Lichti
- Hardwood Tree Improvement and Regeneration Center, Department of Forestry and Natural Resources, Purdue UniversityWest Lafayette, IN, USA
| | - Keith E. Woeste
- Hardwood Tree Improvement and Regeneration Center, Department of Forestry and Natural Resources, Purdue UniversityWest Lafayette, IN, USA
- Hardwood Tree Improvement and Regeneration Center, Northern Research Station, USDA Forest ServiceWest Lafayette, IN, USA
| | - Douglass F. Jacobs
- Hardwood Tree Improvement and Regeneration Center, Department of Forestry and Natural Resources, Purdue UniversityWest Lafayette, IN, USA
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Walsh J, Olsen BJ, Ruskin KJ, Gregory Shriver W, O'Brien KM, Kovach AI. Extrinsic and intrinsic factors influence fitness in an avian hybrid zone. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12837] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Jennifer Walsh
- Department of Natural Resources and the Environment; University of New Hampshire; Durham NH USA
| | - Brian J. Olsen
- School of Biology and Ecology; University of Maine; Orono ME USA
| | | | - W. Gregory Shriver
- Department of Entomology and Wildlife Ecology; University of Delaware; Newark DE USA
| | - Kathleen M. O'Brien
- US Fish and Wildlife Service; Rachel Carson National Wildlife Refuge; Wells ME USA
| | - Adrienne I. Kovach
- Department of Natural Resources and the Environment; University of New Hampshire; Durham NH USA
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Rostgaard Nielsen L, Brandes U, Dahl Kjaer E, Fjellheim S. Introduced Scotch broom (Cytisus scoparius) invades the genome of native populations in vulnerable heathland habitats. Mol Ecol 2016; 25:2790-804. [DOI: 10.1111/mec.13666] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 03/21/2016] [Accepted: 04/12/2016] [Indexed: 11/27/2022]
Affiliation(s)
- Lene Rostgaard Nielsen
- Department of Geosciences and Natural Resource Management; University of Copenhagen; Rolighedsvej 23 Frederiksberg C 1958 Denmark
| | - Ursula Brandes
- Department of Plant Sciences; Norwegian University of Life Sciences; Ås NO-1432 Norway
| | - Erik Dahl Kjaer
- Department of Geosciences and Natural Resource Management; University of Copenhagen; Rolighedsvej 23 Frederiksberg C 1958 Denmark
| | - Siri Fjellheim
- Department of Plant Sciences; Norwegian University of Life Sciences; Ås NO-1432 Norway
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33
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Campbell LG, Lee D, Shukla K, Waite TA, Bartsch D. An ecological approach to measuring the evolutionary consequences of gene flow from crops to wild or weedy relatives. APPLICATIONS IN PLANT SCIENCES 2016; 4:apps1500114. [PMID: 27011898 PMCID: PMC4795919 DOI: 10.3732/apps.1500114] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 01/28/2016] [Indexed: 06/01/2023]
Abstract
PREMISE OF THE STUDY Agricultural practices routinely create opportunities for crops to hybridize with wild relatives, leading to crop gene introgression into wild genomes. Conservationists typically worry this introgression could lead to genetic homogenization of wild populations, over and above the central concern of transgene escape. Alternatively, viewing introgression as analogous to species invasion, we suggest that increased genetic diversity may likewise be an undesirable outcome. METHODS Here, we compare the sensitivity of conventional population genetic metrics with species diversity indices as indicators of the impact of gene flow on genetic diversity. We illustrate this novel approach using multilocus genotype data (12 allozyme loci) from 10 wild (Beta vulgaris subsp. maritima) and eight putative crop-wild hybrid beet populations (B. vulgaris subsp. vulgaris × B. vulgaris subsp. maritima) scattered throughout Europe. RESULTS Conventional population genetic metrics mostly failed to detect shifts in genetic composition of putative hybrid populations. By contrast, species diversity indices unambiguously revealed increased genetic diversity in putative hybrid populations. DISCUSSION We encourage other workers to explore the utility of our more sensitive approach for risk assessment prior to the release of transgenic crops, with a view toward widespread adoption of our method in studies aimed at detecting allelic invasion.
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Affiliation(s)
- Lesley G. Campbell
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario M5B 2K3, Canada
| | - David Lee
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario M5B 2K3, Canada
| | - Kruti Shukla
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario M5B 2K3, Canada
| | - Thomas A. Waite
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, Ohio 43210 USA
| | - Detlef Bartsch
- Abteilung Gentechnik, Bundesamt für Verbraucherschutz und Lebensmittelsicherheit, Mauerstr. 39–42, 10117 Berlin, Germany
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Campbell LG, Teitel Z, Miriti MN. Contemporary evolution and the dynamics of invasion in crop-wild hybrids with heritable variation for two weedy life-histories. Evol Appl 2016; 9:697-708. [PMID: 27247620 PMCID: PMC4869411 DOI: 10.1111/eva.12366] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 01/06/2016] [Indexed: 11/27/2022] Open
Abstract
Gene flow in crop-wild complexes between phenotypically differentiated ancestors may transfer adaptive genetic variation that alters the fecundity and, potentially, the population growth (λ) of weeds. We created biotypes with potentially invasive traits, early flowering or long leaves, in wild radish (Raphanus raphanistrum) and F5 crop-wild hybrid (R. sativus × R. raphanistrum) backgrounds and compared them to randomly mated populations, to provide the first experimental estimate of long-term fitness consequences of weedy life-history variation. Using a life table response experiment design, we modeled λ of experimental, field populations in Pellston, MI, and assessed the relative success of alternative weed strategies and the contributions of individual vital rates (germination, survival, seed production) to differences in λ among experimental populations. Growth rates (λ) were most influenced by seed production, a trait altered by hybridization and selection, compared to other vital rates. More seeds were produced by wild than hybrid populations and by long-leafed than early-flowering lineages. Although we did not detect a biotype by selection treatment effect on lambda, lineages also exhibited contrasting germination and survival strategies. Identifying life-history traits affecting population growth contributes to our understanding of which portions of the crop genome are most likely to introgress into weed populations.
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Affiliation(s)
- Lesley G Campbell
- Department of Chemistry & Biology Ryerson University Toronto ON Canada
| | - Zachary Teitel
- Department of Chemistry & Biology Ryerson University Toronto ON Canada; Present address: Department of Integrative Biology University of Guelph Guelph ON Canada
| | - Maria N Miriti
- Department of Evolution, Ecology and Organismal Biology The Ohio State University Columbus OH USA
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Johnson MG, Lang K, Manos P, Golet GH, Schierenbeck KA. Evidence for genetic erosion of a California native tree, Platanus racemosa, via recent, ongoing introgressive hybridization with an introduced ornamental species. CONSERV GENET 2016. [DOI: 10.1007/s10592-015-0808-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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36
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Zhang JJ, Montgomery BR, Huang SQ. Evidence for asymmetrical hybridization despite pre- and post-pollination reproductive barriers between two Silene species. AOB PLANTS 2016; 8:plw032. [PMID: 27178066 PMCID: PMC4940505 DOI: 10.1093/aobpla/plw032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 04/27/2016] [Indexed: 05/14/2023]
Abstract
Interspecific hybridization is widespread among plants; nevertheless, pre- and post-zygotic isolating mechanisms may maintain species integrity for interfertile species in sympatry despite some gene flow. Interspecific hybridization and potential isolating barriers were evaluated between co-flowering Silene asclepiadea and Silene yunnanensis in an alpine community in southwest China. We investigated morphological and molecular (nuclear microsatellites and chloroplast gene sequence) variation in sympatric populations of S. asclepiadea and S. yunnanensis. Additionally, we analyzed pollinator behaviour and compared reproductive success between the putative hybrids and their parental species. Both the molecular and morphological data indicate that there were putative natural hybrids in the field, with S. asclepiadae the ovule parent and S. yunnanensis the pollen parent. Bumblebees were the primary visitors to S. asclepiadae and putative hybrids, while butterflies were the primary visitors to S. yunnanensis Pollen production and viability were significantly lower in putative hybrids than the parental species. The direction of hybridization is quite asymmetric from S. yunnanensis to S. asclepiadea Protandry combined with later peak flowering of S. yunnanensis, and pollinator preference may have contributed to the asymmetric pattern of hybridization, but putative hybrids were rare. Our results thus suggest that despite gene flow, S. asclepiadea and S. yunnanensis can maintain species boundaries, perhaps as a result of floral isolation and low fecundity of the hybrids.
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Affiliation(s)
- Jin-Ju Zhang
- School of Life Sciences, Central China Normal University, Wuhan 430079, China State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Benjamin R Montgomery
- Division of Natural Sciences & Engineering, University of South Carolina Upstate, Spartanburg, SC 29303, USA
| | - Shuang-Quan Huang
- School of Life Sciences, Central China Normal University, Wuhan 430079, China
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Definition of Eight Mulberry Species in the Genus Morus by Internal Transcribed Spacer-Based Phylogeny. PLoS One 2015; 10:e0135411. [PMID: 26266951 PMCID: PMC4534381 DOI: 10.1371/journal.pone.0135411] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 07/21/2015] [Indexed: 11/19/2022] Open
Abstract
Mulberry, belonging to the order Rosales, family Moraceae, and genus Morus, has received attention because of both its economic and medicinal value, as well as for its important ecological function. The genus Morus has a worldwide distribution, however, its taxonomy remains complex and disputed. Many studies have attempted to classify Morus species, resulting in varied numbers of designated Morus spp. To address this issue, we used information from internal transcribed spacer (ITS) genetic sequences to study the taxonomy of all the members of generally accepted genus Morus. We found that intraspecific 5.8S rRNA sequences were identical but that interspecific 5.8S sequences were diverse. M. alba and M. notabilis showed the shortest (215 bp) and the longest (233 bp) ITS1 sequence length, respectively. With the completion of the mulberry genome, we could identify single nucleotide polymorphisms within the ITS locus in the M. notabilis genome. From reconstruction of a phylogenetic tree based on the complete ITS data, we propose that the Morus genus should be classified into eight species, including M. alba, M. nigra, M. notabilis, M. serrata, M. celtidifolia, M. insignis, M. rubra, and M. mesozygia. Furthermore, the classification of the ITS sequences of known interspecific hybrid clones into both paternal and maternal clades indicated that ITS variation was sufficient to distinguish interspecific hybrids in the genus Morus.
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Genetic characterization of hybridization between native and invasive bittersweet vines (Celastrus spp.). Biol Invasions 2015. [DOI: 10.1007/s10530-015-0926-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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May-McNally SL, Quinn TP, Taylor EB. Low levels of hybridization between sympatric Arctic char (Salvelinus alpinus) and Dolly Varden char (Salvelinus malma) highlights their genetic distinctiveness and ecological segregation. Ecol Evol 2015; 5:3031-45. [PMID: 26356310 PMCID: PMC4559047 DOI: 10.1002/ece3.1583] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 06/02/2015] [Accepted: 06/03/2015] [Indexed: 11/07/2022] Open
Abstract
Understanding the extent of interspecific hybridization and how ecological segregation may influence hybridization requires comprehensively sampling different habitats over a range of life history stages. Arctic char (Salvelinus alpinus) and Dolly Varden (S. malma) are recently diverged salmonid fishes that come into contact in several areas of the North Pacific where they occasionally hybridize. To better quantify the degree of hybridization and ecological segregation between these taxa, we sampled over 700 fish from multiple lake (littoral and profundal) and stream sites in two large, interconnected southwestern Alaskan lakes. Individuals were genotyped at 12 microsatellite markers, and genetic admixture (Q) values generated through Bayesian-based clustering revealed hybridization levels generally lower than reported in a previous study (<0.6% to 5% of samples classified as late-generation hybrids). Dolly Varden and Arctic char tended to make different use of stream habitats with the latter apparently abandoning streams for lake habitats after 2-3 years of age. Our results support the distinct biological species status of Dolly Varden and Arctic char and suggest that ecological segregation may be an important factor limiting opportunities for hybridization and/or the ecological performance of hybrid char.
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Affiliation(s)
- Shannan L May-McNally
- Department of Zoology, Biodiversity Research Centre and Beaty Biodiversity Museum, University of British Columbia 6270 University Ave., Vancouver, BC, Canada, V6T 1Z4
| | - Thomas P Quinn
- School of Aquatic and Fishery Sciences, University of Washington Seattle, Washington, 98195
| | - Eric B Taylor
- Department of Zoology, Biodiversity Research Centre and Beaty Biodiversity Museum, University of British Columbia 6270 University Ave., Vancouver, BC, Canada, V6T 1Z4
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40
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Cinget B, de Lafontaine G, Gérardi S, Bousquet J. Integrating phylogeography and paleoecology to investigate the origin and dynamics of hybrid zones: insights from two widespread North American firs. Mol Ecol 2015; 24:2856-70. [DOI: 10.1111/mec.13194] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 04/02/2015] [Accepted: 04/08/2015] [Indexed: 12/20/2022]
Affiliation(s)
- Benjamin Cinget
- Canada Research Chair in Forest and Environmental Genomics; Centre for Forest Research and Institute for Systems and Integrative Biology; Université Laval; 1030 Avenue de la Médecine Québec QC Canada G1V0A6
| | - Guillaume de Lafontaine
- Canada Research Chair in Forest and Environmental Genomics; Centre for Forest Research and Institute for Systems and Integrative Biology; Université Laval; 1030 Avenue de la Médecine Québec QC Canada G1V0A6
| | - Sébastien Gérardi
- Canada Research Chair in Forest and Environmental Genomics; Centre for Forest Research and Institute for Systems and Integrative Biology; Université Laval; 1030 Avenue de la Médecine Québec QC Canada G1V0A6
| | - Jean Bousquet
- Canada Research Chair in Forest and Environmental Genomics; Centre for Forest Research and Institute for Systems and Integrative Biology; Université Laval; 1030 Avenue de la Médecine Québec QC Canada G1V0A6
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Yao X, Liu L, Yan M, Li D, Zhong C, Huang H. Exon primed intron-crossing (EPIC) markers reveal natural hybridization and introgression in Actinidia (Actinidiaceae) with sympatric distribution. BIOCHEM SYST ECOL 2015. [DOI: 10.1016/j.bse.2015.01.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Balao F, Casimiro-Soriguer R, García-Castaño JL, Terrab A, Talavera S. Big thistle eats the little thistle: does unidirectional introgressive hybridization endanger the conservation of Onopordum hinojense? THE NEW PHYTOLOGIST 2015; 206:448-458. [PMID: 25401776 DOI: 10.1111/nph.13156] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 09/28/2014] [Indexed: 06/04/2023]
Abstract
Hybridization is known to have a creative role in plant evolution. However, it can also have negative effects on parental species. Onopordum is a large genus whose species frequently hybridize. In the Southwest Iberian Peninsula, the rare O. hinojense co-occurs with the widely distributed O. nervosum, and hybrids between these two taxa have been described as O. × onubense. In this study we determine the extinction risk in a hybrid zone, both for hybrids and parentals, using analyses of morphological and cytogenetic traits as well as genetic markers and demographic models. To investigate the introgression process we used amplified fragment length polymorphism (AFLP) markers, Bayesian analyses and genome scan methods. Morphology, genome size and molecular markers confirmed homoploid hybridization and also indicated unidirectional backcrossing of F₁ hybrids with O. nervosum, which is likely to swamp O. hinojense, the parental with lower pollen size and a very low fruit set (8%). Genome scan methods revealed several loci significantly deviating from neutrality. Finally, our demographic modeling indicated that the higher fitness of O. nervosum threats the survival of O. hinojense by demographic swamping. Our study provides strong new evidence for a scenario of rapid extinction by unidirectional introgression and demographic swamping. The multifaceted approach used here sheds new light on the role of introgression in plant extinctions.
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Affiliation(s)
- Francisco Balao
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Apdo. 1095, 41080, Sevilla, Spain
- Department of Systematic and Evolutionary Botany, University of Vienna, Rennweg 14, 1030, Austria
| | - Ramón Casimiro-Soriguer
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Apdo. 1095, 41080, Sevilla, Spain
- Departmento de Biología, CASEM, Universidad de Cádiz, Campus Río San Pedro, E-11510, Puerto Real, Spain
| | - Juan Luis García-Castaño
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Apdo. 1095, 41080, Sevilla, Spain
| | - Anass Terrab
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Apdo. 1095, 41080, Sevilla, Spain
- Department of Systematic and Evolutionary Botany, University of Vienna, Rennweg 14, 1030, Austria
| | - Salvador Talavera
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Apdo. 1095, 41080, Sevilla, Spain
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Genetic architecture and genomic patterns of gene flow between hybridizing species of Picea. Heredity (Edinb) 2015; 115:153-64. [PMID: 25806545 PMCID: PMC4815442 DOI: 10.1038/hdy.2015.19] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 02/17/2015] [Accepted: 02/18/2015] [Indexed: 01/16/2023] Open
Abstract
Hybrid zones provide an opportunity to study the effects of selection and gene flow in natural settings. We employed nuclear microsatellites (single sequence repeat (SSR)) and candidate gene single-nucleotide polymorphism markers (SNPs) to characterize the genetic architecture and patterns of interspecific gene flow in the Picea glauca × P. engelmannii hybrid zone across a broad latitudinal (40–60 degrees) and elevational (350–3500 m) range in western North America. Our results revealed a wide and complex hybrid zone with broad ancestry levels and low interspecific heterozygosity, shaped by asymmetric advanced-generation introgression, and low reproductive barriers between parental species. The clinal variation based on geographic variables, lack of concordance in clines among loci and the width of the hybrid zone points towards the maintenance of species integrity through environmental selection. Congruency between geographic and genomic clines suggests that loci with narrow clines are under strong selection, favoring either one parental species (directional selection) or their hybrids (overdominance) as a result of strong associations with climatic variables such as precipitation as snow and mean annual temperature. Cline movement due to past demographic events (evidenced by allelic richness and heterozygosity shifts from the average cline center) may explain the asymmetry in introgression and predominance of P. engelmannii found in this study. These results provide insights into the genetic architecture and fine-scale patterns of admixture, and identify loci that may be involved in reproductive barriers between the species.
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Li Y, Maki M. Variation in the frequency and extent of hybridization between Leucosceptrum japonicum and L. stellipilum (Lamiaceae) in the Central Japanese Mainland. PLoS One 2015; 10:e0116411. [PMID: 25738505 PMCID: PMC4349587 DOI: 10.1371/journal.pone.0116411] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 12/09/2014] [Indexed: 11/18/2022] Open
Abstract
Variations in the frequency and extent of hybridization among mixed populations located in the same contact zone provide natural laboratories for the study of extrinsic reproductive isolation maintaining species integrity. In this study, we examined the pattern of hybridization between L. japonicum and L. stellipilum among mixed populations in different localities of a contact zone. The genetic structures from three sympatric populations and six mixed populations in the hybrid zone, and five reference populations far from the contact zone, were characterized using 10 neutral nuclear microsatellite markers. Evidence from genetic distance-based clustering analysis, the frequency distribution of admixture proportion values, and the hybrid category assignment approaches indicated that the frequency and extent of hybridization varied considerably among populations in the contact zone between L. japonicum and L. stellipilum. One likely explanation is that variation in exogenous (ecological) selection among populations might contribute to differences in frequency and extent of hybridization. The present study will facilitate future research exploring the evolution of reproductive isolation between L. japonicum and L. stellipilum.
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Affiliation(s)
- Yue Li
- Division of Plant Evolutionary Biology, Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Aoba, Sendai 980–8578, Japan
- Botanical Gardens, Tohoku University, Kawauchi 12–2, Aoba, Sendai 980–0862, Japan
| | - Masayuki Maki
- Botanical Gardens, Tohoku University, Kawauchi 12–2, Aoba, Sendai 980–0862, Japan
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Beatty GE, Barker L, Chen PP, Kelleher CT, Provan J. Cryptic introgression into the kidney saxifrage (Saxifraga hirsuta) from its more abundant sympatric congener Saxifraga spathularis, and the potential risk of genetic assimilation. ANNALS OF BOTANY 2015; 115:179-86. [PMID: 25471098 PMCID: PMC4551084 DOI: 10.1093/aob/mcu226] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 08/26/2014] [Accepted: 09/29/2014] [Indexed: 05/22/2023]
Abstract
BACKGROUND AND AIMS Although hybridization can play a positive role in plant evolution, it has been shown that excessive unidirectional hybridization can result in replacement of a species' gene pool, and even the extinction of rare species via genetic assimilation. This study examines levels of introgression between the common Saxifraga spathularis and its rarer congener S. hirsuta, which have been observed to hybridize in the wild where they occur sympatrically. METHODS Seven species-specific single nucleotide polymorphisms (SNPs) were analysed in 1025 plants representing both species and their hybrid, S. × polita, from 29 sites across their ranges in Ireland. In addition, species distribution modelling was carried out to determine whether the relative abundance of the two parental species is likely to change under future climate scenarios. KEY RESULTS Saxifraga spathularis individuals tended to be genetically pure, exhibiting little or no introgression from S. hirsuta, but significant levels of introgression of S. spathularis alleles into S. hirsuta were observed, indicating that populations exhibiting S. hirsuta morphology are more like a hybrid swarm, consisting of backcrosses and F2s. Populations of the hybrid, S. × polita, were generally comprised of F1s or F2s, with some evidence of backcrossing. Species distribution modelling under projected future climate scenarios indicated an increase in suitable habitats for both parental species. CONCLUSIONS Levels of introgression observed in this study in both S. spathularis and S. hirsuta would appear to be correlated with the relative abundance of the species. Significant introgression of S. spathularis alleles was detected in the majority of the S. hirsuta populations analysed and, consequently, ongoing introgression would appear to represent a threat to the genetic integrity of S. hirsuta, particularly in areas where the species exists sympatrically with its congener and where it is greatly outnumbered.
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Affiliation(s)
- Gemma E Beatty
- School of Biological Sciences, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK, Institute for Global Food Security, Queen's University Belfast, UK and DBN Plant Molecular Laboratory, National Botanic Gardens, Glasnevin, Dublin 9, Ireland School of Biological Sciences, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK, Institute for Global Food Security, Queen's University Belfast, UK and DBN Plant Molecular Laboratory, National Botanic Gardens, Glasnevin, Dublin 9, Ireland
| | - Laura Barker
- School of Biological Sciences, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK, Institute for Global Food Security, Queen's University Belfast, UK and DBN Plant Molecular Laboratory, National Botanic Gardens, Glasnevin, Dublin 9, Ireland
| | - Pei-Pei Chen
- School of Biological Sciences, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK, Institute for Global Food Security, Queen's University Belfast, UK and DBN Plant Molecular Laboratory, National Botanic Gardens, Glasnevin, Dublin 9, Ireland
| | - Colin T Kelleher
- School of Biological Sciences, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK, Institute for Global Food Security, Queen's University Belfast, UK and DBN Plant Molecular Laboratory, National Botanic Gardens, Glasnevin, Dublin 9, Ireland
| | - Jim Provan
- School of Biological Sciences, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK, Institute for Global Food Security, Queen's University Belfast, UK and DBN Plant Molecular Laboratory, National Botanic Gardens, Glasnevin, Dublin 9, Ireland School of Biological Sciences, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK, Institute for Global Food Security, Queen's University Belfast, UK and DBN Plant Molecular Laboratory, National Botanic Gardens, Glasnevin, Dublin 9, Ireland
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El Mujtar VA, Gallo LA, Lang T, Garnier-Géré P. Development of genomic resources forNothofagusspecies using next-generation sequencing data. Mol Ecol Resour 2014; 14:1281-95. [DOI: 10.1111/1755-0998.12276] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 04/23/2014] [Accepted: 04/28/2014] [Indexed: 11/30/2022]
Affiliation(s)
- V. A. El Mujtar
- Unidad de Genética Ecológica y Mejoramiento Forestal; Instituto Nacional de Tecnología Agropecuaria (INTA) EEA Bariloche; Modesta Victoria 4450 (8400) Bariloche Río Negro Argentina
- INRA; UMR 1202 Biodiversity Genes & Communities; F- 33610 Cestas France
- UMR1202 Biodiversity Genes & Communities; University of Bordeaux; Bordeaux F-33400 Talence France
| | - L. A. Gallo
- Unidad de Genética Ecológica y Mejoramiento Forestal; Instituto Nacional de Tecnología Agropecuaria (INTA) EEA Bariloche; Modesta Victoria 4450 (8400) Bariloche Río Negro Argentina
| | - T. Lang
- Key Laboratory of Tropical Forest Ecology; Xishuangbanna Tropical Botanical Garden; Chinese Academy of Sciences; Mengla Yunnan 666303 China
| | - P. Garnier-Géré
- INRA; UMR 1202 Biodiversity Genes & Communities; F- 33610 Cestas France
- UMR1202 Biodiversity Genes & Communities; University of Bordeaux; Bordeaux F-33400 Talence France
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Sousa-Santos C, Gante HF, Robalo J, Proença Cunha P, Martins A, Arruda M, Alves MJ, Almada V. Evolutionary history and population genetics of a cyprinid fish (Iberochondrostoma olisiponensis) endangered by introgression from a more abundant relative. CONSERV GENET 2014. [DOI: 10.1007/s10592-014-0568-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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48
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Hybridization and introgression between the exotic Siberian elm, Ulmus pumila, and the native Field elm, U. minor, in Italy. Biol Invasions 2013. [DOI: 10.1007/s10530-013-0486-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Hoban SM, McCleary TS, Schlarbaum SE, Anagnostakis SL, Romero-Severson J. Human-impacted landscapes facilitate hybridization between a native and an introduced tree. Evol Appl 2012; 5:720-31. [PMID: 23144658 PMCID: PMC3492897 DOI: 10.1111/j.1752-4571.2012.00250.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 12/20/2011] [Indexed: 11/30/2022] Open
Abstract
Spatial and temporal dynamics of hybridization, in particular the influence of local environmental conditions, are well studied for sympatric species but less is known for native-introduced systems, especially for long-lived species. We used microsatellite and chloroplast DNA markers to characterize the influence of anthropogenic landscapes on the extent, direction, and spatial distribution of hybridization between a native North American tree Juglans cinerea (butternut) and an introduced tree Juglans ailantifolia (Japanese walnut) for 1363 trees at 48 locations across the native range of butternut. Remarkably, admixture in anthropogenic sites reached nearly 70%, while fragmented and continuous forests showed minimal admixture (<8%). Furthermore, more hybrids in anthropogenic sites had J. ailantifolia seed parents (95%) than hybrids in fragmented and continuous forests (69% and 59%, respectively). Our results show a strong influence of landscape type on rate and direction of realized gene flow. While hybrids are common in anthropogenic landscapes, our results suggest that even small forested landscapes serve as substantial barriers to hybrid establishment, a key consideration for butternut conservation planning, a species already exhibiting severe decline, and for other North American forest trees that hybridize with introduced congeners.
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Affiliation(s)
- Sean M Hoban
- Department of Biological Sciences, University of Notre Dame Notre Dame, IN, USA
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Nam S, Jang HW, Shibamoto T. Antioxidant activities of extracts from teas prepared from medicinal plants, Morus alba L., Camellia sinensis L., and Cudrania tricuspidata , and their volatile components. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:9097-9105. [PMID: 22871255 DOI: 10.1021/jf301800x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The antioxidant activity of essences of teas prepared from mulberry ( Morus alba L.), Camellia sinensis L., and Cudrania tricuspidata (Carr.) Burea plant was examined using two antioxidant assays. Selected volatile chemicals identified in these plants were also tested for antioxidant activity. All extracts exhibited antioxidant activity with a clear dose response in the aldehyde/carboxylic acid and the malonaldehyde/gas chromatography (MA/GC) assays. Antioxidant activity of extracts at the level of 500 μg/mL ranged from 77.02 ± 0.51% (stems of Burea plant) to 52.57 ± 0.92% (fermented tea of Camellia and stems of Mulberry tea) in the aldehydes/carboxylic acid assay. Their antioxidant activity at the level of 160 μg/mL ranged from 76.17 ± 0.27% (roots of Burea plant) to 59.32 ± 0.27% (stems of Mulberry tea) in the MA/GC assay. Among the positively identified compounds (11 terpenes and terpenoids, 15 alkyl compounds, 26 nitrogen containing heterocyclic compounds, 9 oxygen containing heterocyclic compounds, 18 aromatic compounds, 7 lactones, 6 acids, and 4 miscellaneous compounds), eugenol, 2,5-dihydroxyl acetophenone, and isoeugenol exhibited antioxidant activity comparable to that of BHT in both assays. Vanillin and 2-acetylpyrrole showed potent antioxidant activity in the aldehydes/carboxylic acid assay but only moderate activity in the MA/GC assay. These results suggest that consumption of antioxidant-rich beverages prepared from these plants may be beneficial to human health.
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Affiliation(s)
- Sanghae Nam
- Department of Food Science, Gyeongnam National University of Science & Technology , 33 Dongjinro, Jinju, Gyeongsangnamdo, 660-758, Republic of Korea
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