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Baldwin BG, Wood KR, Freyman WA. Directionally biased habitat shifts and biogeographically informative cytonuclear discordance in the Hawaiian silversword alliance (Compositae). AMERICAN JOURNAL OF BOTANY 2021; 108:2015-2037. [PMID: 34694624 DOI: 10.1002/ajb2.1757] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 07/12/2021] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
PREMISE Expanded phylogenetic analyses of the Hawaiian silversword alliance (Argyroxiphium, Dubautia, Wilkesia; Compositae) were undertaken to assess evolutionary and biogeographic informativeness of cytonuclear discordance and any biases in evolutionary directionality of ecological transitions within this prominent example of adaptive radiation. METHODS Samples spanning the geographic and ecological distributions of all recognized taxa were included in phylogenetic and biogeographic analyses of nuclear ribosomal DNA (nrDNA) and cpDNA sequences. Bayesian model testing approaches were used to model ecological evolution and the evolution of nuclear chromosomal arrangements while accounting for phylogenetic uncertainty. RESULTS Cytonuclear discordance detected previously appears to reflect chloroplast capture, at least in part, with nrDNA trees being largely congruent with nuclear chromosomal structural data and fine-scale taxonomy. Comparison of biogeographic histories estimated from the posterior distributions of nrDNA and cpDNA trees, including inferred chloroplast-capture events, provides additional resolution of dispersal history, including a back-dispersal to Maui Nui from Hawai'i. A newly resolved major nrDNA clade of endemic Kaua'i taxa that mostly were described as new-to-science since the 1980s strengthens the earlier hypothesis that diversification on Kaua'i has not waned since the island began to decline in area through subsidence and erosion. Bias in habitat shifts was estimated, with transitions from dry-to-mesic or -wet and from wet-to-mesic or -bog habitats dominating diversification of the silversword alliance from a dry-adapted tarweed ancestor. CONCLUSIONS The habitat-transition biases estimated here may indicate more limited pathways of ecological evolution than proposed previously for an adaptive radiation involving such major ecological shifts.
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Affiliation(s)
- Bruce G Baldwin
- Jepson Herbarium and Department of Integrative Biology, 1001 Valley Life Sciences Building #2465, University of California, Berkeley, California, 94720-2465, USA
| | - Kenneth R Wood
- National Tropical Botanical Garden, 3530 Papalina Road, Kalaheo, Hawaii, 96741, USA
| | - William A Freyman
- Jepson Herbarium and Department of Integrative Biology, 1001 Valley Life Sciences Building #2465, University of California, Berkeley, California, 94720-2465, USA
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Li J, Zhang Y, Ruhsam M, Milne RI, Wang Y, Wu D, Jia S, Tao T, Mao K. Seeing through the hedge: Phylogenomics of Thuja (Cupressaceae) reveals prominent incomplete lineage sorting and ancient introgression for Tertiary relict flora. Cladistics 2021; 38:187-203. [PMID: 34551153 DOI: 10.1111/cla.12491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 08/15/2021] [Accepted: 08/27/2021] [Indexed: 12/16/2022] Open
Abstract
The Eastern Asia (EA) - North America (NA) disjunction is a well-known biogeographic pattern of the Tertiary relict flora; however, few studies have investigated the evolutionary history of this disjunction using a phylogenomic approach. Here, we used 2369 single copy nuclear genes and nearly full plastomes to reconstruct the evolutionary history of the small Tertiary relict genus Thuja, which consists of five disjunctly distributed species. The nuclear species tree strongly supported an EA clade Thuja standishii-Thuja sutchuenensis and a "disjunct clade", where western NA species T. plicata is sister to an EA-eastern NA disjunct Thuja occidentalis-Thuja koraiensis group. Our results suggested that the observed topological discordance among the gene trees as well as the cytonuclear discordance is mainly due to incomplete lineage sorting, probably facilitated by the fast diversification of Thuja around the Early Miocene and the large effective population sizes of ancestral lineages. Furthermore, approximately 20% of the T. sutchuenensis nuclear genome is derived from an unknown ancestral lineage of Thuja, which might explain the close resemblance of its cone morphology to that of an ancient fossil species. Overall, our study demonstrates that single genes may not resolve interspecific relationships for disjunct taxa, and that more reliable results will come from hundreds or thousands of loci, revealing a more complex evolutionary history. This will steadily improve our understanding of their origin and evolution.
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Affiliation(s)
- Jialiang Li
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, 610065, China
| | - Yujiao Zhang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, 610065, China
| | - Markus Ruhsam
- Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh, EH3 5LR, UK
| | - Richard Ian Milne
- Institute of Molecular Plant Sciences, The University of Edinburgh, Edinburgh, EH9 3JH, UK
| | - Yi Wang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, 610065, China
| | - Dayu Wu
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, 610065, China
| | - Shiyu Jia
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, 610065, China
| | - Tongzhou Tao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, 610065, China
| | - Kangshan Mao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, 610065, China.,College of Science, Tibet University, Lhasa, Xizang Autonomous Region, 850012, China
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Köhler M, Oakley LJ, Font F, Peñas MLL, Majure LC. On the continuum of evolution: a putative new hybrid speciation event in Opuntia (Cactaceae) between a native and an introduced species in southern South America. SYST BIODIVERS 2021. [DOI: 10.1080/14772000.2021.1967510] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Matias Köhler
- Programa de Pós-Graduação em Botânica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- University of Florida Herbarium (FLAS), Florida Museum of Natural History, Gainesville, FL, USA
| | - Luis J. Oakley
- Cátedra de Botánica, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, Santa Fe, Argentina
- Red List Authority Coordinator for the Temperate South American Plant Specialist Groups – International Union for Conservation of Nature (IUCN), Gland, Switzerland
| | - Fabián Font
- Herbario Museo de Farmacobotánica “Juan A. Domínguez” (BAF), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - M. Laura Las Peñas
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), Facultas de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba – CONICET, Córdoba, Argentina
| | - Lucas C. Majure
- University of Florida Herbarium (FLAS), Florida Museum of Natural History, Gainesville, FL, USA
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Owens GL, Todesco M, Bercovich N, Légaré JS, Mitchell N, Whitney KD, Rieseberg LH. Standing variation rather than recent adaptive introgression probably underlies differentiation of the texanus subspecies of Helianthus annuus. Mol Ecol 2021; 30:6229-6245. [PMID: 34080243 DOI: 10.1111/mec.16008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 05/17/2021] [Accepted: 05/26/2021] [Indexed: 12/24/2022]
Abstract
The origins of geographic races in wide-ranging species are poorly understood. In Texas, the texanus subspecies of Helianthus annuus has long been thought to have acquired its defining phenotypic traits via introgression from a local congener, H. debilis, but previous tests of this hypothesis were inconclusive. Here, we explore the origins of H. a. texanus using whole genome sequencing data from across the entire range of H. annuus and possible donor species, as well as phenotypic data from a common garden study. We found that although it is morphologically convergent with H. debilis, H. a. texanus has conflicting signals of introgression. Genome wide tests (Patterson's D and TreeMix) only found evidence of introgression from H. argophyllus (sister species to H. annuus and also sympatric), but not H. debilis, with the exception of one individual of 109 analysed. We further scanned the genome for localized signals of introgression using PCAdmix and found minimal but nonzero introgression from H. debilis and significant introgression from H. argophyllus in some populations. Given the paucity of introgression from H. debilis, we argue that the morphological convergence observed in Texas is probably from standing genetic variation. We also found that genomic differentiation in H. a. texanus is mostly driven by large segregating inversions, several of which have signatures of natural selection based on haplotype frequencies.
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Affiliation(s)
- Gregory L Owens
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Marco Todesco
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Natalia Bercovich
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Jean-Sébastien Légaré
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Nora Mitchell
- Department of Biology, University of Wisconsin - Eau Claire, Eau Claire, WI, USA.,Department of Biology, University of New Mexico, Albuquerque, NM, USA
| | - Kenneth D Whitney
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
| | - Loren H Rieseberg
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
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Nge FJ, Biffin E, Thiele KR, Waycott M. Reticulate Evolution, Ancient Chloroplast Haplotypes, and Rapid Radiation of the Australian Plant Genus Adenanthos (Proteaceae). Front Ecol Evol 2021. [DOI: 10.3389/fevo.2020.616741] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cytonuclear discordance, commonly detected in phylogenetic studies, is often attributed to hybridization and/or incomplete lineage sorting (ILS). New sequencing technologies and analytical approaches can provide new insights into the relative importance of these processes. Hybridization has previously been reported in the Australian endemic plant genus Adenanthos (Proteaceae). Like many Australian genera, Adenanthos is of relatively ancient origin, and provides an opportunity to examine long-term evolutionary consequences of gene flow between lineages. Using a hybrid capture approach, we assembled densely sampled low-copy nuclear and plastid DNA sequences for Adenanthos, inferred its evolutionary history, and used a Bayesian posterior predictive approach and coalescent simulations to assess relative contributions of hybridization and ILS to cytonuclear discordance. Our analyses indicate that strong incongruence detected between our plastid and nuclear phylogenies is not only the result of ILS, but also results from extensive ancient introgression as well as recent chloroplast capture and introgression between extant Adenanthos species. The deep reticulation was also detected from long-persisting chloroplast haplotypes shared between evolutionarily distant species. These haplotypes may have persisted for over 12 Ma in localized populations across southwest Western Australia, indicating that the region is not only an important area for old endemic lineages and accumulation of species, but is also characterized by persistence of high genetic diversity. Deep introgression in Adenanthos coincided with the rapid radiation of the genus during the Miocene, a time when many Australian temperate plant groups radiated in response to large-scale climatic change. This study suggests that ancient introgression may play an important role in the evolution of the Australian flora more broadly.
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Turner KG, Ostevik KL, Grassa CJ, Rieseberg LH. Genomic Analyses of Phenotypic Differences Between Native and Invasive Populations of Diffuse Knapweed (Centaurea diffusa). Front Ecol Evol 2021. [DOI: 10.3389/fevo.2020.577635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Invasive species represent excellent opportunities to study the evolutionary potential of traits important to success in novel environments. Although some ecologically important traits have been identified in invasive species, little is typically known about the genetic mechanisms that underlie invasion success in non-model species. Here, we use a genome-wide association (GWAS) approach to identify the genetic basis of trait variation in the non-model, invasive, diffuse knapweed [Centaurea diffusa Lam. (Asteraceae)]. To assist with this analysis, we have assembled the first draft genome reference and fully annotated plastome assembly for this species, and one of the first from this large, weedy, genus, which is of major ecological and economic importance. We collected phenotype data from 372 individuals from four native and four invasive populations of C. diffusa grown in a common environment. Using these individuals, we produced reduced-representation genotype-by-sequencing (GBS) libraries and identified 7,058 SNPs. We identify two SNPs associated with leaf width in these populations, a trait which significantly varies between native and invasive populations. In this rosette forming species, increased leaf width is a major component of increased biomass, a common trait in invasive plants correlated with increased fitness. Finally, we use annotations from Arabidopsis thaliana to identify 98 candidate genes that are near the associated SNPs and highlight several good candidates for leaf width variation.
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57
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Kandziora M, Sklenář P, Kolář F, Schmickl R. How to Tackle Phylogenetic Discordance in Recent and Rapidly Radiating Groups? Developing a Workflow Using Loricaria (Asteraceae) as an Example. FRONTIERS IN PLANT SCIENCE 2021; 12:765719. [PMID: 35069621 PMCID: PMC8777076 DOI: 10.3389/fpls.2021.765719] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 11/22/2021] [Indexed: 05/17/2023]
Abstract
A major challenge in phylogenetics and -genomics is to resolve young rapidly radiating groups. The fast succession of species increases the probability of incomplete lineage sorting (ILS), and different topologies of the gene trees are expected, leading to gene tree discordance, i.e., not all gene trees represent the species tree. Phylogenetic discordance is common in phylogenomic datasets, and apart from ILS, additional sources include hybridization, whole-genome duplication, and methodological artifacts. Despite a high degree of gene tree discordance, species trees are often well supported and the sources of discordance are not further addressed in phylogenomic studies, which can eventually lead to incorrect phylogenetic hypotheses, especially in rapidly radiating groups. We chose the high-Andean Asteraceae genus Loricaria to shed light on the potential sources of phylogenetic discordance and generated a phylogenetic hypothesis. By accounting for paralogy during gene tree inference, we generated a species tree based on hundreds of nuclear loci, using Hyb-Seq, and a plastome phylogeny obtained from off-target reads during target enrichment. We observed a high degree of gene tree discordance, which we found implausible at first sight, because the genus did not show evidence of hybridization in previous studies. We used various phylogenomic analyses (trees and networks) as well as the D-statistics to test for ILS and hybridization, which we developed into a workflow on how to tackle phylogenetic discordance in recent radiations. We found strong evidence for ILS and hybridization within the genus Loricaria. Low genetic differentiation was evident between species located in different Andean cordilleras, which could be indicative of substantial introgression between populations, promoted during Pleistocene glaciations, when alpine habitats shifted creating opportunities for secondary contact and hybridization.
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Affiliation(s)
- Martha Kandziora
- Department of Botany, Faculty of Science, Charles University, Prague, Czechia
- *Correspondence: Martha Kandziora,
| | - Petr Sklenář
- Department of Botany, Faculty of Science, Charles University, Prague, Czechia
| | - Filip Kolář
- Department of Botany, Faculty of Science, Charles University, Prague, Czechia
- Institute of Botany, The Czech Academy of Sciences, Průhonice, Czechia
| | - Roswitha Schmickl
- Department of Botany, Faculty of Science, Charles University, Prague, Czechia
- Institute of Botany, The Czech Academy of Sciences, Průhonice, Czechia
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58
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Uckele KA, Adams RP, Schwarzbach AE, Parchman TL. Genome-wide RAD sequencing resolves the evolutionary history of serrate leaf Juniperus and reveals discordance with chloroplast phylogeny. Mol Phylogenet Evol 2020; 156:107022. [PMID: 33242585 DOI: 10.1016/j.ympev.2020.107022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 10/06/2020] [Accepted: 11/17/2020] [Indexed: 12/22/2022]
Abstract
Juniper (Juniperus) is an ecologically important conifer genus of the Northern Hemisphere, the members of which are often foundational tree species of arid regions. The serrate leaf margin clade is native to topologically variable regions in North America, where hybridization has likely played a prominent role in their diversification. Here we use a reduced-representation sequencing approach (ddRADseq) to generate a phylogenomic data set for 68 accessions representing all 22 species in the serrate leaf margin clade, as well as a number of close and distant relatives, to improve understanding of diversification in this group. Phylogenetic analyses using three methods (SVDquartets, maximum likelihood, and Bayesian) yielded highly congruent and well-resolved topologies. These phylogenies provided improved resolution relative to past analyses based on Sanger sequencing of nuclear and chloroplast DNA, and were largely consistent with taxonomic expectations based on geography and morphology. Calibration of a Bayesian phylogeny with fossil evidence produced divergence time estimates for the clade consistent with a late Oligocene origin in North America, followed by a period of elevated diversification between 12 and 5 Mya. Comparison of the ddRADseq phylogenies with a phylogeny based on Sanger-sequenced chloroplast DNA revealed five instances of pronounced discordance, illustrating the potential for chloroplast introgression, chloroplast transfer, or incomplete lineage sorting to influence organellar phylogeny. Our results improve understanding of the pattern and tempo of diversification in Juniperus, and highlight the utility of reduced-representation sequencing for resolving phylogenetic relationships in non-model organisms with reticulation and recent divergence.
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Affiliation(s)
- Kathryn A Uckele
- Department of Biology, MS 314, University of Nevada, Reno, Max Fleischmann Agriculture Building, 1664 N Virginia St., Reno, NV 89557, USA.
| | - Robert P Adams
- Baylor University, Utah Lab, 201 N 5500 W, Hurricane, UT 84790, USA.
| | - Andrea E Schwarzbach
- Department of Health and Biomedical Sciences, University of Texas - Rio Grande Valley, 1 W University Drive, Brownsville, TX 78520, USA.
| | - Thomas L Parchman
- Department of Biology, MS 314, University of Nevada, Reno, Max Fleischmann Agriculture Building, 1664 N Virginia St., Reno, NV 89557, USA.
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Ren T, Li ZX, Xie DF, Gui LJ, Peng C, Wen J, He XJ. Plastomes of eight Ligusticum species: characterization, genome evolution, and phylogenetic relationships. BMC PLANT BIOLOGY 2020; 20:519. [PMID: 33187470 PMCID: PMC7663912 DOI: 10.1186/s12870-020-02696-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 10/12/2020] [Indexed: 05/24/2023]
Abstract
BACKGROUND The genus Ligusticum consists of approximately 60 species distributed in the Northern Hemisphere. It is one of the most taxonomically difficult taxa within Apiaceae, largely due to the varied morphological characteristics. To investigate the plastome evolution and phylogenetic relationships of Ligusticum, we determined the complete plastome sequences of eight Ligusticum species using a de novo assembly approach. RESULTS Through a comprehensive comparative analysis, we found that the eight plastomes were similar in terms of repeat sequence, SSR, codon usage, and RNA editing site. However, compared with the other seven species, L. delavayi exhibited striking differences in genome size, gene number, IR/SC borders, and sequence identity. Most of the genes remained under the purifying selection, whereas four genes showed relaxed selection, namely ccsA, rpoA, ycf1, and ycf2. Non-monophyly of Ligusticum species was inferred from the plastomes and internal transcribed spacer (ITS) sequences phylogenetic analyses. CONCLUSION The plastome tree and ITS tree produced incongruent tree topologies, which may be attributed to the hybridization and incomplete lineage sorting. Our study highlighted the advantage of plastome with mass informative sites in resolving phylogenetic relationships. Moreover, combined with the previous studies, we considered that the current taxonomy system of Ligusticum needs to be improved and revised. In summary, our study provides new insights into the plastome evolution, phylogeny, and taxonomy of Ligusticum species.
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Affiliation(s)
- Ting Ren
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Zi-Xuan Li
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Deng-Feng Xie
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Ling-Jian Gui
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Chang Peng
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Jun Wen
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Xing-Jin He
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China.
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Bianconi ME, Dunning LT, Curran EV, Hidalgo O, Powell RF, Mian S, Leitch IJ, Lundgren MR, Manzi S, Vorontsova MS, Besnard G, Osborne CP, Olofsson JK, Christin PA. Contrasted histories of organelle and nuclear genomes underlying physiological diversification in a grass species. Proc Biol Sci 2020; 287:20201960. [PMID: 33171085 PMCID: PMC7735283 DOI: 10.1098/rspb.2020.1960] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
C4 photosynthesis evolved multiple times independently in angiosperms, but most origins are relatively old so that the early events linked to photosynthetic diversification are blurred. The grass Alloteropsis semialata is an exception, as this species encompasses C4 and non-C4 populations. Using phylogenomics and population genomics, we infer the history of dispersal and secondary gene flow before, during and after photosynthetic divergence in A. semialata. We further analyse the genome composition of individuals with varied ploidy levels to establish the origins of polyploids in this species. Detailed organelle phylogenies indicate limited seed dispersal within the mountainous region of origin and the emergence of a C4 lineage after dispersal to warmer areas of lower elevation. Nuclear genome analyses highlight repeated secondary gene flow. In particular, the nuclear genome associated with the C4 phenotype was swept into a distantly related maternal lineage probably via unidirectional pollen flow. Multiple intraspecific allopolyploidy events mediated additional secondary genetic exchanges between photosynthetic types. Overall, our results show that limited dispersal and isolation allowed lineage divergence, with photosynthetic innovation happening after migration to new environments, and pollen-mediated gene flow led to the rapid spread of the derived C4 physiology away from its region of origin.
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Affiliation(s)
- Matheus E Bianconi
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Luke T Dunning
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Emma V Curran
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Oriane Hidalgo
- Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK
| | - Robyn F Powell
- Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK
| | - Sahr Mian
- Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK
| | - Ilia J Leitch
- Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK
| | - Marjorie R Lundgren
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Sophie Manzi
- Laboratoire Evolution and Diversité Biologique (EDB UMR5174), Université de Toulouse III - Paul Sabatier, CNRS, IRD, 118 route de Narbonne, 31062 Toulouse, France
| | - Maria S Vorontsova
- Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK
| | - Guillaume Besnard
- Laboratoire Evolution and Diversité Biologique (EDB UMR5174), Université de Toulouse III - Paul Sabatier, CNRS, IRD, 118 route de Narbonne, 31062 Toulouse, France
| | - Colin P Osborne
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Jill K Olofsson
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Pascal-Antoine Christin
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
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Meerow AW, Gardner EM, Nakamura K. Phylogenomics of the Andean Tetraploid Clade of the American Amaryllidaceae (Subfamily Amaryllidoideae): Unlocking a Polyploid Generic Radiation Abetted by Continental Geodynamics. FRONTIERS IN PLANT SCIENCE 2020; 11:582422. [PMID: 33250911 PMCID: PMC7674842 DOI: 10.3389/fpls.2020.582422] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 10/12/2020] [Indexed: 05/27/2023]
Abstract
One of the two major clades of the endemic American Amaryllidaceae subfam. Amaryllidoideae constitutes the tetraploid-derived (n = 23) Andean-centered tribes, most of which have 46 chromosomes. Despite progress in resolving phylogenetic relationships of the group with plastid and nrDNA, certain subclades were poorly resolved or weakly supported in those previous studies. Sequence capture using anchored hybrid enrichment was employed across 95 species of the clade along with five outgroups and generated sequences of 524 nuclear genes and a partial plastome. Maximum likelihood phylogenetic analyses were conducted on concatenated supermatrices, and coalescent-based species tree analyses were run on the gene trees, followed by hybridization network, age diversification and biogeographic analyses. The four tribes Clinantheae, Eucharideae, Eustephieae, and Hymenocallideae (sister to Clinantheae) are resolved in all analyses with > 90 and mostly 100% support, as are almost all genera within them. Nuclear gene supermatrix and species tree results were largely in concordance; however, some instances of cytonuclear discordance were evident. Hybridization network analysis identified significant reticulation in Clinanthus, Hymenocallis, Stenomesson and the subclade of Eucharideae comprising Eucharis, Caliphruria, and Urceolina. Our data support a previous treatment of the latter as a single genus, Urceolina, with the addition of Eucrosia dodsonii. Biogeographic analysis and penalized likelihood age estimation suggests an origin in the Cauca, Desert and Puna Neotropical bioprovinces for the complex in the mid-Oligocene, with more dispersals than vicariances in its history, but no extinctions. Hymenocallis represents the only instance of long-distance vicariance from the tropical Andean origin of its tribe Hymenocallideae. The absence of extinctions correlates with the lack of diversification rate shifts within the clade. The Eucharideae experienced a sudden lineage radiation ca. 10 Mya. We tie much of the divergences in the Andean-centered lineages to the rise of the Andes, and suggest that the Amotape-Huancabamba Zone functioned as both a corridor (dispersal) and a barrier to migration (vicariance). Several taxonomic changes are made. This is the largest DNA sequence data set to be applied within Amaryllidaceae to date.
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Affiliation(s)
- Alan W. Meerow
- USDA-ARS-SHRS, National Clonal Germplasm Repository, Miami, FL, United States
| | - Elliot M. Gardner
- Singapore Botanic Gardens, National Parks Board, Singapore, Singapore
- Institute of Environment, Florida International University, Miami, FL, United States
| | - Kyoko Nakamura
- USDA-ARS-SHRS, National Clonal Germplasm Repository, Miami, FL, United States
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Forsythe ES, Nelson ADL, Beilstein MA. Biased Gene Retention in the Face of Introgression Obscures Species Relationships. Genome Biol Evol 2020; 12:1646-1663. [PMID: 33011798 PMCID: PMC7533067 DOI: 10.1093/gbe/evaa149] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2020] [Indexed: 12/13/2022] Open
Abstract
Phylogenomic analyses are recovering previously hidden histories of hybridization, revealing the genomic consequences of these events on the architecture of extant genomes. We applied phylogenomic techniques and several complementary statistical tests to show that introgressive hybridization appears to have occurred between close relatives of Arabidopsis, resulting in cytonuclear discordance and impacting our understanding of species relationships in the group. The composition of introgressed and retained genes indicates that selection against incompatible cytonuclear and nuclear-nuclear interactions likely acted during introgression, whereas linkage also contributed to genome composition through the retention of ancient haplotype blocks. We also applied divergence-based tests to determine the species branching order and distinguish donor from recipient lineages. Surprisingly, these analyses suggest that cytonuclear discordance arose via extensive nuclear, rather than cytoplasmic, introgression. If true, this would mean that most of the nuclear genome was displaced during introgression whereas only a small proportion of native alleles were retained.
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63
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Liu Z, Gu W, Seiler GJ, Jan CC. A Unique Cytoplasmic-Nuclear Interaction in Sunflower ( Helianthus annuus L.) Causing Reduced-Vigor Plants and the Genetics of Vigor Restoration. FRONTIERS IN PLANT SCIENCE 2020; 11:1010. [PMID: 32754176 PMCID: PMC7367100 DOI: 10.3389/fpls.2020.01010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 06/19/2020] [Indexed: 06/11/2023]
Abstract
Wild Helianthus species are an important genetic resource for sunflower improvement, but sometimes there are adverse interactions between the wild and cultivated sunflowers. This study reports the inheritance of reduced vigor and its restoration resulting from an interaction of perennial Helianthus cytoplasms with nuclear genes of cultivated sunflower lines. The large number of vigor restoration (V) genes identified in cultivated lines are all located at the same locus, designated V1 , suggesting a common origin of these genes. Additional V genes derived from the wild perennial species H. giganteus L. and H. hirsutus Raf. are located at a different locus than V1 , designated V2 . A major difference between the wild annual Helianthus cytoplasms and perennial cytoplasms is the lack of the vigor-reducing cytoplasms, but surprisingly V genes were observed in wild annual H. annuus L. and H. petiolaris Nutt. which were at the same locus as V1 . A common vigor-reducing cytoplasmic effect of the perennial Helianthus species and the existence of a common vigor restoration V gene in most perennial Helianthus species could be explained as a result of vigor selection during Helianthus speciation. V1 was mapped on linkage group (LG) 7 of the sunflower genome, using an F2 population derived from MOL-RV/HA 821. V1 co-segregated with an InDel marker ZVG31, with three single-nucleotide polymorphism (SNP) markers, SFW01024, SFW07230, and SFW00604, located above it on the map at a genetic distance of 0.8 cM, and another SNP marker, SFW08671, below it at a distance of 0.4 cM. The physical distance between the two closest flanking SNP markers corresponds to 0.56 and 1.37 Mb on the HA 412-HO and XRQ assemblies, respectively. The tightly linked markers will help select normal vigor progenies when using perennial Helianthus cytoplasms in a breeding program, which will also provide a basis for studying the mechanism of the cytonuclear interaction, and the speciation of annual and perennial Helianthus species.
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Affiliation(s)
- Zhao Liu
- Department of Plant Sciences, North Dakota State University, Fargo, ND, United States
| | - Wei Gu
- Institute of Plant Protection, Postdoctoral Program, Heilongjiang Academy of Agricultural Sciences, Harbin, China
| | - Gerald J. Seiler
- USDA-ARS, Edward T. Schafer Agricultural Research Center, Fargo, ND, United States
| | - Chao-Chien Jan
- USDA-ARS, Edward T. Schafer Agricultural Research Center, Fargo, ND, United States
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64
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Massive haplotypes underlie ecotypic differentiation in sunflowers. Nature 2020; 584:602-607. [PMID: 32641831 DOI: 10.1038/s41586-020-2467-6] [Citation(s) in RCA: 186] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 04/16/2020] [Indexed: 12/22/2022]
Abstract
Species often include multiple ecotypes that are adapted to different environments1. However, it is unclear how ecotypes arise and how their distinctive combinations of adaptive alleles are maintained despite hybridization with non-adapted populations2-4. Here, by resequencing 1,506 wild sunflowers from 3 species (Helianthus annuus, Helianthus petiolaris and Helianthus argophyllus), we identify 37 large (1-100 Mbp in size), non-recombining haplotype blocks that are associated with numerous ecologically relevant traits, as well as soil and climate characteristics. Limited recombination in these haplotype blocks keeps adaptive alleles together, and these regions differentiate sunflower ecotypes. For example, haplotype blocks control a 77-day difference in flowering between ecotypes of the silverleaf sunflower H. argophyllus (probably through deletion of a homologue of FLOWERING LOCUS T (FT)), and are associated with seed size, flowering time and soil fertility in dune-adapted sunflowers. These haplotypes are highly divergent, frequently associated with structural variants and often appear to represent introgressions from other-possibly now-extinct-congeners. These results highlight a pervasive role of structural variation in ecotypic adaptation.
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65
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Rose JP, Toledo CAP, Lemmon EM, Lemmon AR, Sytsma KJ. Out of Sight, Out of Mind: Widespread Nuclear and Plastid-Nuclear Discordance in the Flowering Plant Genus Polemonium (Polemoniaceae) Suggests Widespread Historical Gene Flow Despite Limited Nuclear Signal. Syst Biol 2020; 70:162-180. [PMID: 32617587 DOI: 10.1093/sysbio/syaa049] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 06/10/2020] [Accepted: 06/23/2020] [Indexed: 12/13/2022] Open
Abstract
Phylogenomic data from a rapidly increasing number of studies provide new evidence for resolving relationships in recently radiated clades, but they also pose new challenges for inferring evolutionary histories. Most existing methods for reconstructing phylogenetic hypotheses rely solely on algorithms that only consider incomplete lineage sorting (ILS) as a cause of intra- or intergenomic discordance. Here, we utilize a variety of methods, including those to infer phylogenetic networks, to account for both ILS and introgression as a cause for nuclear and cytoplasmic-nuclear discordance using phylogenomic data from the recently radiated flowering plant genus Polemonium (Polemoniaceae), an ecologically diverse genus in Western North America with known and suspected gene flow between species. We find evidence for widespread discordance among nuclear loci that can be explained by both ILS and reticulate evolution in the evolutionary history of Polemonium. Furthermore, the histories of organellar genomes show strong discordance with the inferred species tree from the nuclear genome. Discordance between the nuclear and plastid genome is not completely explained by ILS, and only one case of discordance is explained by detected introgression events. Our results suggest that multiple processes have been involved in the evolutionary history of Polemonium and that the plastid genome does not accurately reflect species relationships. We discuss several potential causes for this cytoplasmic-nuclear discordance, which emerging evidence suggests is more widespread across the Tree of Life than previously thought. [Cyto-nuclear discordance, genomic discordance, phylogenetic networks, plastid capture, Polemoniaceae, Polemonium, reticulations.].
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Affiliation(s)
- Jeffrey P Rose
- Department of Botany, University of Wisconsin-Madison, Madison, WI 53706, USA.,Department of Biology, University of Nebraska at Kearney, Kearney, NE 68849, USA
| | - Cassio A P Toledo
- Programa de Pós-Graduação em Biologia Vegetal, Instituto de Biolgia, Universidade Estadual de Campinas-UNICAMP, Rua Monteiro Lobato, 255, Campinas, SP. CEP: 13083-862, Brazil
| | - Emily Moriarty Lemmon
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Alan R Lemmon
- Department of Scientific Computing, Florida State University, Tallahassee, FL 32306, USA
| | - Kenneth J Sytsma
- Department of Botany, University of Wisconsin-Madison, Madison, WI 53706, USA
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66
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Morales-Briones DF, Kadereit G, Tefarikis DT, Moore MJ, Smith SA, Brockington SF, Timoneda A, Yim WC, Cushman JC, Yang Y. Disentangling Sources of Gene Tree Discordance in Phylogenomic Data Sets: Testing Ancient Hybridizations in Amaranthaceae s.l. Syst Biol 2020; 70:219-235. [PMID: 32785686 PMCID: PMC7875436 DOI: 10.1093/sysbio/syaa066] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 03/01/2020] [Accepted: 09/03/2020] [Indexed: 12/26/2022] Open
Abstract
Gene tree discordance in large genomic data sets can be caused by evolutionary processes such as incomplete lineage sorting and hybridization, as well as model violation, and errors in data processing, orthology inference, and gene tree estimation. Species tree methods that identify and accommodate all sources of conflict are not available, but a combination of multiple approaches can help tease apart alternative sources of conflict. Here, using a phylotranscriptomic analysis in combination with reference genomes, we test a hypothesis of ancient hybridization events within the plant family Amaranthaceae s.l. that was previously supported by morphological, ecological, and Sanger-based molecular data. The data set included seven genomes and 88 transcriptomes, 17 generated for this study. We examined gene-tree discordance using coalescent-based species trees and network inference, gene tree discordance analyses, site pattern tests of introgression, topology tests, synteny analyses, and simulations. We found that a combination of processes might have generated the high levels of gene tree discordance in the backbone of Amaranthaceae s.l. Furthermore, we found evidence that three consecutive short internal branches produce anomalous trees contributing to the discordance. Overall, our results suggest that Amaranthaceae s.l. might be a product of an ancient and rapid lineage diversification, and remains, and probably will remain, unresolved. This work highlights the potential problems of identifiability associated with the sources of gene tree discordance including, in particular, phylogenetic network methods. Our results also demonstrate the importance of thoroughly testing for multiple sources of conflict in phylogenomic analyses, especially in the context of ancient, rapid radiations. We provide several recommendations for exploring conflicting signals in such situations. [Amaranthaceae; gene tree discordance; hybridization; incomplete lineage sorting; phylogenomics; species network; species tree; transcriptomics.]
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Affiliation(s)
- Diego F Morales-Briones
- Department of Plant and Microbial Biology, University of Minnesota-Twin Cities, 1445 Gortner Avenue, St. Paul, MN 55108, USA
| | - Gudrun Kadereit
- Institut für Molekulare Physiologie, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - Delphine T Tefarikis
- Institut für Molekulare Physiologie, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - Michael J Moore
- Department of Biology, Oberlin College, Science Center K111, 119 Woodland Street, Oberlin, OH 44074-1097, USA
| | - Stephen A Smith
- Department of Ecology & Evolutionary Biology, University of Michigan, 830 North University Avenue, Ann Arbor, MI 48109-1048, USA
| | - Samuel F Brockington
- Department of Plant Sciences, University of Cambridge, Tennis Court Road, Cambridge CB2 3EA, UK
| | - Alfonso Timoneda
- Department of Plant Sciences, University of Cambridge, Tennis Court Road, Cambridge CB2 3EA, UK
| | - Won C Yim
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, 89577, USA
| | - John C Cushman
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, 89577, USA
| | - Ya Yang
- Department of Plant and Microbial Biology, University of Minnesota-Twin Cities, 1445 Gortner Avenue, St. Paul, MN 55108, USA
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67
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Postel Z, Touzet P. Cytonuclear Genetic Incompatibilities in Plant Speciation. PLANTS 2020; 9:plants9040487. [PMID: 32290056 PMCID: PMC7238192 DOI: 10.3390/plants9040487] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/03/2020] [Accepted: 04/07/2020] [Indexed: 12/13/2022]
Abstract
Due to the endosymbiotic origin of organelles, a pattern of coevolution and coadaptation between organellar and nuclear genomes is required for proper cell function. In this review, we focus on the impact of cytonuclear interaction on the reproductive isolation of plant species. We give examples of cases where species exhibit barriers to reproduction which involve plastid-nuclear or mito-nuclear genetic incompatibilities, and describe the evolutionary processes at play. We also discuss potential mechanisms of hybrid fitness recovery such as paternal leakage. Finally, we point out the possible interplay between plant mating systems and cytonuclear coevolution, and its consequence on plant speciation.
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68
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Skim-Sequencing Reveals the Likely Origin of the Enigmatic Endangered Sunflower Helianthus schweinitzii. Genes (Basel) 2019; 10:genes10121040. [PMID: 31847493 PMCID: PMC6947582 DOI: 10.3390/genes10121040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/05/2019] [Accepted: 12/12/2019] [Indexed: 12/13/2022] Open
Abstract
Resolving the origin of endangered taxa is an essential component of conservation. This information can be used to guide efforts of bolstering genetic diversity, and also enables species recovery and future evolutionary studies. Here, we used low-coverage whole genome sequencing to clarify the origin of Helianthus schweinitzii, an endangered tetraploid sunflower that is endemic to the Piedmont Plateau in the eastern United States. We surveyed four accessions representing four populations of H. schweinitzii and 38 accessions of six purported parental species. Using de novo approaches, we assembled 87,004 bp of the chloroplast genome and 6770 bp of the nuclear 35S rDNA. Phylogenetic reconstructions based on the chloroplast genome revealed no reciprocal monophyly of taxa. In contrast, nuclear rDNA data strongly supported the currently accepted sections of the genus Helianthus. Information from combined cpDNA and rDNA provided evidence that H. schweinitzii is likely an allo-tetraploid that formed as a result of hybridization between the diploids Helianthus giganteus and Helianthus microcephalus.
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69
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Development of Plastid Genomic Resources for Discrimination and Classification of Epimedium wushanense (Berberidaceae). Int J Mol Sci 2019; 20:ijms20164003. [PMID: 31426439 PMCID: PMC6720487 DOI: 10.3390/ijms20164003] [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: 06/24/2019] [Revised: 08/03/2019] [Accepted: 08/14/2019] [Indexed: 02/07/2023] Open
Abstract
Epimedium wushanense (Berberidaceae) is recorded as the source plant of Epimedii Wushanensis Folium in the Chinese Pharmacopoeia. However, controversies exist on the classification of E. wushanense and its closely related species, namely, E. pseudowushanense, E. chlorandrum, E. mikinorii, E. ilicifolium, and E. borealiguizhouense. These species are often confused with one another because of their highly similar morphological characteristics. This confusion leads to misuse in the medicinal market threatening efficiency and safety. Here, we studied the plastid genomes of these Epimedium species. Results show that the plastid genomes of E. wushanense and its relative species are typical circular tetramerous structure, with lengths of 156,855–158,251 bp. A total of 112 genes were identified from the Epimedium plastid genomes, including 78 protein-coding, 30 tRNA, and 4 rRNA genes. A loss of rpl32 gene in E. chlorandrum was found for the first time in this study. The phylogenetic trees constructed indicated that E. wushanense can be distinguished from its closely related species. E. wushanense shows a closer relationship to species in ser. Dolichocerae. In conclusion, the use of plastid genomes contributes useful genetic information for identifying medicinally important species E. wushanense and provides new evidence for understanding phylogenetic relationships within the Epimedium genus.
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70
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Zhang X, Deng T, Moore MJ, Ji Y, Lin N, Zhang H, Meng A, Wang H, Sun Y, Sun H. Plastome phylogenomics of Saussurea (Asteraceae: Cardueae). BMC PLANT BIOLOGY 2019; 19:290. [PMID: 31266465 PMCID: PMC6604455 DOI: 10.1186/s12870-019-1896-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 06/19/2019] [Indexed: 05/12/2023]
Abstract
BACKGROUND Saussurea DC. is one of the largest and most morphologically heterogeneous genera in Asteraceae. The relationships within Saussurea have been poorly resolved, probably due an early, rapid radiation. To examine plastome evolution and resolve backbone relationships within Saussurea, we sequenced the complete plastomes of 17 species representing all four subgenera. RESULTS All Saussurea plastomes shared the gene content and structure of most Asteraceae plastomes. Molecular evolutionary analysis showed most of the plastid protein-coding genes have been under purifying selection. Phylogenomic analyses of 20 Saussurea plastomes that alternatively included nucleotide or amino acid sequences of all protein-coding genes, vs. the nucleotide sequence of the entire plastome, supported the monophyly of Saussurea and identified three clades within it. Three of the four traditional subgenera were recovered as paraphyletic. Seven plastome regions were identified as containing the highest nucleotide variability. CONCLUSIONS Our analyses reveal both the structural conservatism and power of the plastome for resolving relationships in congeneric taxa. It is very likely that differences in topology among data sets is due primarily to differences in numbers of parsimony-informative characters. Our study demonstrates that the current taxonomy of Saussurea is likely based at least partly on convergent morphological character states. Greater taxon sampling will be necessary to explore character evolution and biogeography in the genus. Our results here provide helpful insight into which loci will provide the most phylogenetic signal in Saussurea and Cardueae.
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Affiliation(s)
- Xu Zhang
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, Hubei, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China
| | - Tao Deng
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China
| | - Michael J Moore
- Department of Biology, Oberlin College, 119 Woodland St, Oberlin, OH, USA
| | - Yunheng Ji
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China
| | - Nan Lin
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, Hubei, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China
| | - Huajie Zhang
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, Hubei, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Aiping Meng
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, Hubei, China
| | - Hengchang Wang
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, Hubei, China.
| | - Yanxia Sun
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, Hubei, China.
| | - Hang Sun
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China.
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71
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Olmstead RG, Bedoya AM. Whole genomes: the holy grail. A commentary on: 'Molecular phylogenomics of the tribe Shoreeae (Dipterocarpaceae) using whole plastidgenomes'. ANNALS OF BOTANY 2019; 123:iv-v. [PMID: 31106809 PMCID: PMC6526312 DOI: 10.1093/aob/mcz055] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This article comments on: Jacqueline Heckenhauer, Ovidiu Paun, Mark W. Chase, Peter S. Ashton, A.S. Kamariah and Rosabelle Samuel. 2019. Molecular phylogenomics of the tribe Shoreeae (Dipterocarpaceae) using whole plastid genomes. Annals of Botany 123(5): 857–865.
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Affiliation(s)
| | - Ana M Bedoya
- Department of Biology, University of Washington, Seattle, WA, USA
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72
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Wang S, Song Q, Li S, Hu Z, Dong G, Song C, Huang H, Liu Y. Assembly of a Complete Mitogenome of Chrysanthemum nankingense Using Oxford Nanopore Long Reads and the Diversity and Evolution of Asteraceae Mitogenomes. Genes (Basel) 2018; 9:E547. [PMID: 30424578 PMCID: PMC6267336 DOI: 10.3390/genes9110547] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 11/03/2018] [Accepted: 11/07/2018] [Indexed: 12/22/2022] Open
Abstract
Diversity in structure and organization is one of the main features of angiosperm mitochondrial genomes (mitogenomes). The ultra-long reads of Oxford Nanopore Technology (ONT) provide an opportunity to obtain a complete mitogenome and investigate the structural variation in unprecedented detail. In this study, we compared mitogenome assembly methods using Illumina and/or ONT sequencing data and obtained the complete mitogenome (208 kb) of Chrysanthemum nankingense based on the hybrid assembly method. The mitogenome encoded 19 transfer RNA genes, three ribosomal RNA genes, and 34 protein-coding genes with 21 group II introns disrupting eight intron-contained genes. A total of seven medium repeats were related to homologous recombination at different frequencies as supported by the long ONT reads. Subsequently, we investigated the variations in gene content and constitution of 28 near-complete mitogenomes from Asteraceae. A total of six protein-coding genes were missing in all Asteraceae mitogenomes, while four other genes were not detected in some lineages. The core fragments (~88 kb) of the Asteraceae mitogenomes had a higher GC content (~46.7%) than the variable and specific fragments. The phylogenetic topology based on the core fragments of the Asteraceae mitogenomes was highly consistent with the topologies obtained from the corresponding plastid datasets. Our results highlighted the advantages of the complete assembly of the C. nankingense mitogenome and the investigation of its structural variation based on ONT sequencing data. Moreover, the method based on local collinear blocks of the mitogenomes could achieve the alignment of highly rearrangeable and variable plant mitogenomes as well as construct a robust phylogenetic topology.
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Affiliation(s)
- Shuaibin Wang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, the Chinese Academy of Sciences, Guangzhou 510650, China.
- Guangdong Provincial Key Laboratory of Applied Botany, Guangzhou 510650, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Qingwei Song
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, the Chinese Academy of Sciences, Guangzhou 510650, China.
- Guangdong Provincial Key Laboratory of Applied Botany, Guangzhou 510650, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Shanshan Li
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, the Chinese Academy of Sciences, Guangzhou 510650, China.
- Guangdong Provincial Key Laboratory of Applied Botany, Guangzhou 510650, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Zhigang Hu
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, China.
| | | | - Chi Song
- Wuhan Benagen Tech Solutions Company Limited, Wuhan 430070, China.
| | - Hongwen Huang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, the Chinese Academy of Sciences, Guangzhou 510650, China.
| | - Yifei Liu
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, China.
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