| 1. |
- Ferm, Julia, et al.
(författare)
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Phylogeny of the Neotropical legume genera Zygia and Marmaroxylon and close relatives
- 2019
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Ingår i: Taxon. - : International Association for Plant Taxonomy. - 0040-0262 .- 1996-8175. ; 68:4, s. 661-672
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Tidskriftsartikel (refereegranskat)abstract
- The Neotropical legume genera Zygia and Marmaroxylon have traditionally been considered closely related and are sometimes treated as congeners. They have been referred to the mimosoid tribe Ingeae based on their possession of flowers with basally fused stamen filaments. However, their systematic status and position have not been analysed in a phylogenetic context. This study provides the first molecular phylogeny of Zygia and Marmaroxylon and closely related mimosoid legume genera, particularly from the tribe Ingeae. DNA sequence data were derived from the nuclear external transcribed spacer (ETS) and the internal transcribed spacer (ITS), and from the chloroplast psbA-trnH and trnL-trnF regions, and were analysed using Bayesian inference. In all, 29 species of Zygia and 7 species of Marmaroxylon were included in the study along with representative species from the closely related genera Abarema, Acacia s.str., Archidendropsis, Calliandra, Chloroleucon, Cojoba, Faidherbia, Havardia, Hydrochorea, Inga, Leucochloron, Macrosamanea, Pithecellobium, Pseudosamanea, Samanea, Senegalia, Vachellia and Zapoteca. The results show that neither Zygia nor Marmaroxylon are monophyletic as presently circumscribed. Furthermore, these two genera are not monophyletic together. None of the nine presently recognized sections of Zygia that contain more than one species are shown to be monophyletic. Two of the monospecific sections of Zygia, sect. Ingopsis (Z. inundata) and sect. Pseudocojoba (Z. sabatieri), were found in a clade together with species of Inga. Marmaroxylon ocumarense and M. magdalenae, previously treated as synonyms (as Zygia), are not conspecific, and are found in a clade with Macrosamanea and in a clade with species of Abarema and Hydrochorea, respectively. Our results also show the Inga alliance to be non-monophyletic. In correspondence with the results presented, all species referred to Marmaroxylon, except for M. ocumarense and M. magdalenae, are here included in Zygia, and Z. inundata is treated in Inga, in which genus it was first described.
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| 2. |
- Geiger, Jennifer M.O., et al.
(författare)
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Molecular phylogenetic relationships of Cibotium and origin of the Hawaiian endemics
- 2013
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Ingår i: American Fern Journal. - : American Fern Society. - 0002-8444 .- 1938-422X. ; 103:3, s. 141-152
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Tidskriftsartikel (refereegranskat)abstract
- The tree fern genus Cibotium comprises nine species distributed in tropical regions of Asia, Mesoamerica, and the Hawaiian Islands. The four Hawaiian species are endemic to the Hawaiian Islands. The goals of this paper were to determine the relationships among the Cibotium species, determine whether the Hawaiian species are monophyletic, and infer the dispersal pathway likely responsible for delivering an ancestral Cibotium species to the Hawaiian Islands. Molecular phylogenetic analyses based on four coding and five non-coding plastid DNA sequences supported Hawaiian Cibotium as monophyletic, suggesting a single colonization of the Hawaiian Islands. Hawaiian Cibotium are most closely related to species in Mesoamerica. If the ancestor of Hawaiian Cibotium dispersed to the Hawaiian Islands via wind dispersed spores, our analyses suggest the trade winds or storms delivered spores from Mesoamerica or the Hawaiian Islands were colonized first by a species from Asia, followed by subsequent dispersal to Mesoamerica from Hawai'i. Our analyses do not allow us to favor one hypothesis over the other.
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| 3. |
- Kao, Tzu-Tong, et al.
(författare)
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Origins of the Endemic Scaly Tree Ferns on the Galapagos and Cocos Islands
- 2015
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Ingår i: International journal of plant sciences. - : University of Chicago Press. - 1058-5893 .- 1537-5315. ; 176:9, s. 869-879
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Tidskriftsartikel (refereegranskat)abstract
- Premise of research.Successful long-distance dispersal is rarely observed in scaly tree ferns (Cyatheaceae). Nevertheless, recent molecular evidence has suggested that the four endemic scaly tree ferns on the Galapagos Archipelago (Cyathea weatherbyana) and Cocos Island (Cyathea alfonsiana, Cyathea nesiotica, and Cyathea notabilis), two oceanic island groups west of Central and northern South America, probably each originated from different mainland America ancestors. However, the phylogenetic relationships inferred among these endemics and their mainland relatives have been unclear. This study is aimed at better resolving the relationships and tracing the origins of these island endemics.Methodology.Five plastid regions from 35 Cyathea species were analyzed to reconstruct phylogenetic relationships using parsimony, likelihood, and Bayesian approaches. We also estimated divergence times of these species, and our chronogram was used to reconstruct their biogeographical range history.Pivotal results.Our well-resolved phylogenetic tree of Cyathea, which is in agreement with previous studies, shows that when the four Galapagos and Cocos endemics are included, they each belong to separate subclades. Our biogeographical study suggests that the four endemics originated from independent colonization events from mainland America and that there was no dispersal of Cyathea between the island groups. We reveal more detailed relationships among the endemics and their respective close mainland relatives; some of these relationships differ from previous studies. Our findings are corroborated by new morphological data from ongoing stem anatomy studies.Conclusions.The four scaly tree ferns endemic to the Galapagos and Cocos Islands each did indeed originate as independent colonization events from separate sources in mainland America, and their closest relatives are identified here.
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| 4. |
- Korall, Petra, 1968-, et al.
(författare)
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A molecular phylogeny of scaly tree ferns (Cyatheaceae)
- 2007
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Ingår i: American Journal of Botany. - : Wiley. - 0002-9122 .- 1537-2197. ; 94:5, s. 873-886
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Tidskriftsartikel (refereegranskat)abstract
- Tree ferns recently were identified as the closest sister group to the hyperdiverse clade of ferns, the polypods. Although most of the 600 species of tree ferns are arborescent, the group encompasses a wide range of morphological variability, from diminutive members to the giant scaly tree ferns, Cyatheaceae. This well-known family comprises most of the tree fern diversity (similar to 500 species) and is widespread in tropical, subtropical, and south temperate regions of the world. Here we investigate the phylogenetic relationships of scaly tree ferns based on DNA sequence data from five plastid regions (rbcL, rbcL-accD IGS, rbcL-atpB IGS, trnG-trnR, and trnL-trnF). A basal dichotomy resolves Sphaeropteris as sister to all other taxa and scale features support these two clades: Sphaeropteris has conform scales, whereas all other taxa have marginate scales. The marginate-scaled clade consists of a basal trichotomy, with the three groups here termed (1) Cyathea (including Cnemidaria, Hymenophyllopsis, Trichipteris), (2) Alsophila sensu stricto, and (3) Gymnosphaera (previously recognized as a section within Alsophila) + A. capensis. Scaly tree ferns display a wide range of indusial structures, and although indusium shape is homoplastic it does contain useful phylogenetic information that supports some of the larger clades recognised.
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| 5. |
- Korall, Petra, et al.
(författare)
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ABRUPT DECELERATION OF MOLECULAR EVOLUTION LINKED TO THE ORIGIN OF ARBORESCENCE IN FERNS
- 2010
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Ingår i: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; 64:9, s. 2786-2792
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Tidskriftsartikel (refereegranskat)abstract
- Molecular rate heterogeneity, whereby rates of molecular evolution vary among groups of organisms, is a well-documented phenomenon. Nonetheless, its causes are poorly understood. For animals, generation time is frequently cited because longer-lived species tend to have slower rates of molecular evolution than their shorter-lived counterparts. Although a similar pattern has been uncovered in flowering plants, using proxies such as growth form, the underlying process has remained elusive. Here, we find a deceleration of molecular evolutionary rate to be coupled with the origin of arborescence in ferns. Phylogenetic branch lengths within the ""tree fern"" clade are considerably shorter than those of closely related lineages, and our analyses demonstrate that this is due to a significant difference in molecular evolutionary rate. Reconstructions reveal that an abrupt rate deceleration coincided with the evolution of the long-lived tree-like habit at the base of the tree fern clade. This suggests that a generation time effect may well be ubiquitous across the green tree of life, and that the search for a responsible mechanism must focus on characteristics shared by all vascular plants. Discriminating among the possibilities will require contributions from various biological disciplines, but will be necessary for a full appreciation of molecular evolution.
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| 6. |
- Korall, Petra, 1968-, et al.
(författare)
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Global biogeography of scaly tree ferns (Cyatheaceae): evidence for Gondwanan vicariance and limited transoceanic dispersal
- 2014
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Ingår i: Journal of Biogeography. - : Wiley-Blackwell. - 0305-0270 .- 1365-2699. ; 41:2, s. 402-413
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Tidskriftsartikel (refereegranskat)abstract
- AimScaly tree ferns, Cyatheaceae, are a well-supported group of mostly tree-forming ferns found throughout the tropics, the subtropics and the south-temperate zone. Fossil evidence shows that the lineage originated in the Late Jurassic period. We reconstructed large-scale historical biogeographical patterns of Cyatheaceae and tested the hypothesis that some of the observed distribution patterns are in fact compatible, in time and space, with a vicariance scenario related to the break-up of Gondwana.LocationTropics, subtropics and south-temperate areas of the world.MethodsThe historical biogeography of Cyatheaceae was analysed in a maximum likelihood framework using Lagrange. The 78 ingroup taxa are representative of the geographical distribution of the entire family. The phylogenies that served as a basis for the analyses were obtained by Bayesian inference analyses of mainly previously published DNA sequence data using MrBayes. Lineage divergence dates were estimated in a Bayesian Markov chain Monte Carlo framework using beast.ResultsCyatheaceae originated in the Late Jurassic in either South America or Australasia. Following a range expansion, the ancestral distribution of the marginate-scaled clade included both these areas, whereas Sphaeropteris is reconstructed as having its origin only in Australasia. Within the marginate-scaled clade, reconstructions of early divergences are hampered by the unresolved relationships among the Alsophila, Cyathea and Gymnosphaera lineages. Nevertheless, it is clear that the occurrence of the Cyathea and Sphaeropteris lineages in South America may be related to vicariance, whereas transoceanic dispersal needs to be inferred for the range shifts seen in Alsophila and Gymnosphaera.Main conclusionsThe evolutionary history of Cyatheaceae involves both Gondwanan vicariance scenarios as well as long-distance dispersal events. The number of transoceanic dispersals reconstructed for the family is rather few when compared with other fern lineages. We suggest that a causal relationship between reproductive mode (outcrossing) and dispersal limitations is the most plausible explanation for the pattern observed.
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| 7. |
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| 8. |
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| 9. |
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| 10. |
- Korall, Petra, 1968-, et al.
(författare)
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PHYLOGENETIC RELATIONSHIPS IN SELAGINELLACEAE BASED ON RBCL SEQUENCES
- 2002
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Ingår i: American Journal of Botany. - 0002-9122 .- 1537-2197. ; 89:3, s. 506-517
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Tidskriftsartikel (refereegranskat)abstract
- A phylogenetic framework is developed for the clubmoss family Selaginellaceae based on maximum parsimony analyses of molecular data. The chloroplast gene rbcL was sequenced for 62 species, which represent nearly 10% of living species diversity in the family. Taxa were chosen to reflect morphological, geographical, and ecological diversity. The analyses provide support for monophyly of subgenera Selaginella and Tetragonostachys. Stachygynandrum and Heterostachys are polyphyletic. Monophyly of Ericetorum is uncertain. Results also indicate a large number of new groupings not previously recognized on morphological grounds. Some of these new groups seem to have corresponding morphological synapomorphies, such as the presence of rhizophores (distinctive root-like structures), aspects of rhizophore development, and leaf and stem morphology. Others share distinctive ecological traits (e.g., xerophytism). For many groups, however, no morphological, ecological, or physiological markers are known. This could reflect patchy sampling and a lack of detailed knowledge about many species. Despite a lengthy fossil record dating from the Carboniferous Period, cladogram topology indicates that most of the living tropical species are probably the products of more recent diversifications. Resurrection plants, extreme xerophytes characterized by aridity-driven inrolling of branches and rapid revival on rehydration, have evolved at least three times in quite different clades.
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| 11. |
- Korall, Petra, 1968-
(författare)
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Phylogeny of Selaginellaceae
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The phylogeny of Selaginellaceae, a small, but historically important family of heterosporous lycopods, has been the focus of this thesis. The approximately 700 extant species are herbaceous and distributed all over the world, with most species in the tropics and subtropics. Lycopods constituted a dominant element of the Upper Carboniferous flora, but Selaginellaceae were probably established already in the Lower Carboniferous some 345 million years ago, as revealed by macrofossil data. Major patterns of relationships were investigated based on a representative sample of global diversity and molecular (plastid gene rbcL, nuclear region 26S rDNA) and morphological data. Analyses were performed using parsimony and Bayesian inference. A survey of megaspore surface and wall structures was carried out for living species and included in the phylogenetic analyses. The resulting phylogenetic trees were used to evaluate various hypotheses on the evolution of the group, including the origins of tropical and temperate species diversity, as well as the evolution of xerophytism. Results showed that Selaginellaceae are monophyletic, and many subclades were identified. In a basal dichotomy two species, Selaginella selaginoides (L.) Link and S. deflexa Brackenridge, appear in a strongly supported clade as sister group to a clade comprising all other species (rhizophoric clade). The rhizophoric clade is recognised by the presence of rhizophores, which are highly characteristic root-like organs, and on the presence of decussately arranged sporophylls. Within the rhizophoric clade a basal dichotomy is most often found resulting in two more or less equally sized sister groups. These and many other groupings within these clades are new and have not previously been recognized in any other systematic study. Some of the new groups seem to have corresponding morphological synapomorphies, such as aspects of rhizophore development and megaspore characteristics. Others share distinctive ecological traits (e.g., xerophytism). For many groups, however, no morphological, ecological, or physiological markers are yet known.The inclusion of megaspore fossils allowed for tentative ages to be assigned to certain clades within the family. The phylogenetic tree is inconclusive with regard to a tropical or temperate origin of modern species diversity, but there is clear evidence for multiple independent origins of xerophytic strategies. Besides the phylogenetic results, this study reveals exceptionally high levels of substitution rates and rate heterogeneity in Selaginellaceae.
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| 12. |
- Korall, Petra, 1968-, et al.
(författare)
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Phylogeny of selaginellaceae : Evaluation of generic subgeneric relationships based on rbcL gene sequences
- 1999
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Ingår i: International journal of plant sciences. - : University of Chicago Press. - 1058-5893 .- 1537-5315. ; 160:3, s. 585-594
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Tidskriftsartikel (refereegranskat)abstract
- A cladistic analysis based on rbcL gene sequences from a representative sample of 18 species yields three most parsimonious trees that strongly support monophyly of Selaginellaceae. Within Selaginellaceae, the morphologically distinctive subgenus Selaginella is resolved as sister group to a clade composed of all other species, here termed the rhizophoric clade. In the rhizophoric clade, subgenus Stachygynandrum is paraphyletic to subgenera Ericetorum, Tetragonostachys, and Heterostachys. Monophyly of Ericetorum and Tetragonostachys is strongly corroborated. Results support a close relationship between "resurrection plants" in Stachygynandrum and the mat-forming or tufted drought-tolerant species of Tetragonostachys, indicating a common origin of xerophytism in these groups. A close relationship for all isophyllous species, as hypothesized in many classifications, is not supported by the rbcL data. Leaf isophylly and reduction in Ericetorum and Tetragonostachys most probably represent independent reversals of the marked anisophyllous condition in Stachygynandrum, Leaf reduction is one of a suite of characters that may have evolved in response to seasonal drought.
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| 13. |
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| 14. |
- Korall, Petra, 1968-, et al.
(författare)
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Tree ferns : Monophyletic groups and their relationships as revealed by four protein-coding plastid loci
- 2006
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 39:3, s. 830-845
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Tidskriftsartikel (refereegranskat)abstract
- Tree ferns are a well-established clade within leptosporangiate ferns. Most of the 600 species (in seven families and 13 genera) are arborescent, but considerable morphological variability exists, spanning the giant scaly tree ferns (Cyatheaceae), the low, erect plants (Plagiogyriaceae), and the diminutive endemics of the Guayana Highlands (Hymenophyllopsidaceae). In this study, we investigate phylogenetic relationships within tree ferns based on analyses of four protein-coding, plastid loci (atpA, atpB, rbeL, and rps4). Our results reveal four well-supported clades, with genera of Dicksoniaceae (sensu Kubitzki, 1990) interspersed among them: (A) (Loxomataceae, (Culcita, Plagiogyriaceae)), (B) (Calochlaena, (Dicksonia, Lophosoriaceae)), (C) Cibotium, and (D) Cyatheaceae, with Hymenophyllopsidaceae nested within. How these four groups are related to one other, to Thyrsopteris, or to Metaxyaceae is weakly supported. Our results show that Dicksoniaceae and Cyatheaceae, as currently recognised, are not monophyletic and new circumscriptions for these families are needed. (c) 2006 Elsevier Inc. All rights reserved.
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| 15. |
- Larsson, Anders, et al.
(författare)
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Extensive polyploid hybridization within the fern genus Woodsia
- 2013
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In the process of resolving the phylogeny of the cosmopolitan Woodsia ferns we have conducted the most comprehensive nuclear phylogeny of ferns. We have sequenced two nuclear regions (pgiC and RPA2) on up to 175 different specimen corresponding to some 30 species. In addition to the nuclear markers we have also sequenced 5 chloroplast regions (matK, rbcL, atpA, atpB and trnGR).The results show an extensive hybridization and chromosome doubling within the genus Woodsia. As many as 19 out of the 32 species we identify in the phylogeny are polyploids.The Scandinavian species Woodsia alpina is the allopolyploid hybrid of Woodsia ilvensis x Woodsia glabella. In this study we show that the hybrid has originated multiple times, and also that both parents have, at least once each, acted as the donor of the maternally inherited chloroplast genome.An extreme hybrid is Woodsia ×abbeae. It is an hybrid between the two species Woodsia ilvensis and Woodsia oregana ssp. cathcartiana separated by as much as 30-50 million years.
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| 16. |
- Larsson, Anders, et al.
(författare)
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Omfattande hybridisering inom ormbunkssläktet Hällebräken (Woodsia)
- 2012
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- För att kunna beskriva hällebräknarnas släktskap samt omfattningen av hybridisering vid deras artbildning har vi genomfört den hittills största studien med nukleära markörer av ormbunkars släktskap. För upp till 170 olika kollekter fördelat på ca 30 arter har vi har sekvenserat två olika nukleära regioner (pgiC och RPA2), samt även 5 kloroplastregioner (matK, rbcL, atpA, atpB och trnGR).Analysen visar att det har skett och fortfarande pågår en omfattande hybridisering och kromosomfördubbling inom ormbunkssläktet Woodsia.Vi kan också visa den i Sverige förekommande fjällhällebräken (Woodsia alpina) har uppstått flera gånger och är en allopolyploid hybrid mellan hällebräken och dvärghällebräken (Woodsia ilvensis x Woodsia glabella). Skillnaden i gensekvenser mellan fjällhällebräken (Woodsia alpina) och föräldraarterna är minimal vilket innebär att hybridisering har skett nyligen alternativt sker kontinuerligt.För att ytterligare belysa hällebräknarnas promiskuösa leverne kan noteras att spontan hybridisering sker mellan arter som gick skilda vägar för så länge sedan som uppskattningsvis 30-50 miljoner år sedan (Woodsia ilvensis x Woodsia oregana ssp. oregana).Vi tittade även på de olika arternas utbredning och det visar sig att deras geografiska utbredning korrelerar mycket väl med släktträdet. Närstående arter har nästan alltid närliggande utbredningsområden. Att ormbunkar med sina små sporer skulle vara väldigt lättspridda bekräftas inte (de etablerar sig iallafall inte på platser långt från deras kärnområde). Ett undantag finns dock där arten Woodsia montevidensis har spridids från Sydamerika till Afrika och etablerat en population där.
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| 17. |
- Larsson, Anders, et al.
(författare)
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Phylogeny of Woodsia (Woodsiaceae): recent speciation through polyploidization is common in old diploid stock.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Woodsia is a genus of small tufted ferns growing in rocky habitats. It is widely distributed in temperate and montane regions of the world. Through previous cytological studies and allozyme work it is known to have a complex evolutionary history and includes numerous polyploid taxa and hybrids. We present here for the first time detailed phylogenetic analyses of a wide range of taxa within Woodsia, including samples from many chromosome-counted specimens. Five plastid (atpA, atpB, matK, rbcL and trnG-R) and two nuclear (pgiC and RPA2) regions have been used from an ingroup of 188 samples representing 36 taxa and six hybrids. In a complementary expanded analysis the polyploid speciation frequency is estimated within the 10 families most closely related to Woodsiaceae (the Eupolypods II). Woodsia is monophyletic if the often segregated genera Protowoodsia, Cheilanthopsis and Hymenocystis are included. The genus comprises two major well-supported clades, one including the circumboreal and most of the Asian species, and the other including all American and the remaining Asian species. The split between these clades is estimated to 45 Ma. Woodsia × abbae is a remarkable triploid hybrid between members of these two clades. Most taxa in Woodsia are polyploid and polyploidization is the most common mode of speciation in the genus with an estimated polyploid speciation rate of 54%. The polyploids are mostly young. Some of the polyploid taxa, such as W. alpina and W. obtusa, seem to have been formed multiple times. The Eupolypod II study agrees with the Woodsia study in showing a high proportion of polyploids with a polyploid speciation rate of 46%. Old polyploid lineages are rare. The circumboreal species do not form a monophyletic group and are nested among various Asian species, whereas the "American clade" is monophyletic and nested among Asian species. Within the American clade W. montevidensis has its main distribution in South America, but also has made a recent leap to Southern Africa and Madagascar.
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| 18. |
- Larsson, Anders
(författare)
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Systematics of Woodsia : Ferns, bioinformatics and more
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Ferns are one of the three main clades of vascular plants. They have few easily studied morphological characters, reflected in a historically unstable classification. The fern genus Woodsia is known to have a complex evolutionary history including numerous polyploid taxa and hybrids. It is a cosmopolitan group of small rock loving ferns mainly found in montane areas.This thesis aims at analyzing the patterns of diploid and polyploid evolution in Woodsia and to resolve and classify the relationships of Woodsiaceae and the other families in the large fern clade Eupolypods II.The Eupolypods II family relationships were inferred with DNA sequences from 81 specimens representing all major lineages. This resulted in the first well supported phylogeny of this clade and revealed Woodsiaceae to be non-monophyletic. The genera previously placed in this family were reclassified into five new or resurrected families. Swedish fern genera that have changed family classification are Woodsia (hällebräknar), now in the monogeneric family Woodsiaceae, Athyrium (majbräknar), now in Athyriaceeae and Cystopteris (stenbräknar) and Gymnocarpium (ekbräknar) now in Cystopteridaceae.To analyze the evolution of Woodsia, phylogenies were produced from five plastid and two nuclear regions sequenced from 188 specimens. The results show that most taxa in Woodsia are polyploid. Polyploidization is the most common mode of speciation in the genus with an estimated polyploid speciation rate of 54%. The polyploids are mostly young and many of the polyploid taxa seem to have formed multiple times. The results also address several taxonomic and biogeographic questions.In the process of the work we made methodological advancements and developed 20 new low copy nuclear marker regions as well as a software pipeline for finding primers in transcriptome datasets. The alignment editor software AliView was developed for handling the increasing size datasets in a user friendly way.In conclusion this thesis provides new insights into the complexities of the evolution of a fern genus in which much of the diversity is accommodated in young species formed through polyploidization. It provides a framework of phylogenetic relationships at different levels that both answers long standing questions and generates new ones.
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| 19. |
- Larsson, Anders, et al.
(författare)
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"Var hör hällebräken, ekbräken och svartbräknar hemma? - Äntligen en fylogeni över Eupolypods II"
- 2010
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Konferensbidrag (refereegranskat)abstract
- De flesta ormbunkar ser nästan likadana ut och det finns tämligen få morfologiska synapomorfier som ger indikationer på hur släkten och familjer relaterar till varandra. Detta har gjort att familjeavgränsningar och inbördes familjerelationer har varit , inte minst inom Eupolypods II. Denna stora gruppering omfattar ca 1/3 av världens ormbunksarter fördelade inom familjerna Woodsiaceae (hällebräkenväxter), Thelypteridaceae (kärrbräkenväxter), Aspleniaceae (svartbräkenväxter), Blechnaceae (kambräkenväxter) och Onocleaceae. Vill du ha svenska namnen först och latinet i parentes som du har på artnamnen nedan??Med hjälp av sekvensdata från fem kloroplastregioner (rbcL, atpA, atpB, trnG-R, matK) från 81 arter, vilka innefattar samtliga tidigare svårplacerade släkten, har vi lyckats beskriva tidigare okända relationer inom Eupolypods II, och utvärderat monofylin hos familjerna..Analysen visar att stenbräken (Cystopteris fragilis) och ekbräken (Gymnocarpium dryopteris) ingår i systergruppen till övriga ormbunkar i Eupolypods II .Vidare är Woodsiaceae i sin nuvarande avgränsning parafyletisk och måste omformas. Om man vill behålla namnet Woodsiaceae innebär det att familjen blir monotypisk och endast innefattar släktet Woodsia, Hällebräknar.
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| 20. |
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| 21. |
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| 22. |
- Rothfels, Carl J., et al.
(författare)
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Overcoming Deep Roots, Fast Rates, and Short Internodes to Resolve the Ancient Rapid Radiation of Eupolypod II Ferns
- 2012
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Ingår i: Systematic Biology. - : Oxford University Press (OUP). - 1063-5157 .- 1076-836X. ; 61:3, s. 490-509
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Tidskriftsartikel (refereegranskat)abstract
- Backbone relationships within the large eupolypod II clade, which includes nearly a third of extant fern species, have resisted elucidation by both molecular and morphological data. Earlier studies suggest that much of the phylogenetic intractability of this group is due to three factors: (i) a long root that reduces apparent levels of support in the ingroup; (ii) long ingroup branches subtended by a series of very short backbone internodes (the "ancient rapid radiation" model); and (iii) significantly heterogeneous lineage-specific rates of substitution. To resolve the eupolypod II phylogeny, with a particular emphasis on the backbone internodes, we assembled a data set of five plastid loci (atpA, atpB, matK, rbcL, and trnG-R) from a sample of 81 accessions selected to capture the deepest divergences in the clade. We then evaluated our phylogenetic hypothesis against potential confounding factors, including those induced by rooting, ancient rapid radiation, rate heterogeneity, and the Bayesian star-tree paradox artifact. While the strong support we inferred for the backbone relationships proved robust to these potential problems, their investigation revealed unexpected model-mediated impacts of outgroup composition, divergent effects of methods for countering the star-tree paradox artifact, and gave no support to concerns about the applicability of the unrooted model to data sets with heterogeneous lineage-specific rates of substitution. This study is among few to investigate these factors with empirical data, and the first to compare the performance of the two primary methods for overcoming the Bayesian star-tree paradox artifact. Among the significant phylogenetic results is the near-complete support along the eupolypod II backbone, the demonstrated paraphyly of Woodsiaceae as currently circumscribed, and the well-supported placement of the enigmatic genera Homalosorus, Diplaziopsis, and Woodsia.
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| 23. |
- Rothfels, Carl J., et al.
(författare)
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The evolutionary history of ferns inferred from 25 low-copy nuclear genes
- 2015
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Ingår i: American Journal of Botany. - : Wiley. - 0002-9122 .- 1537-2197. ; 102:7, s. 1089-1107
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Tidskriftsartikel (refereegranskat)abstract
- PREMISE OF THE STUDY: Understanding fern (monilophyte) phylogeny and its evolutionary timescale is critical for broad investigations of the evolution of land plants, and for providing the point of comparison necessary for studying the evolution of the fern sister group, seed plants. Molecular phylogenetic investigations have revolutionized our understanding of fern phylogeny, however, to date, these studies have relied almost exclusively on plastid data. METHODS: Here we take a curated phylogenomics approach to infer the first broad fern phylogeny from multiple nuclear loci, by combining broad taxon sampling (73 ferns and 12 outgroup species) with focused character sampling (25 loci comprising 35 877 bp), along with rigorous alignment, orthology inference and model selection. KEY RESULTS: Our phylogeny corroborates some earlier inferences and provides novel insights; in particular, we find strong support for Equisetales as sister to the rest of ferns, Marattiales as sister to leptosporangiate ferns, and Dennstaedtiaceae as sister to the eupolypods. Our divergence-time analyses reveal that divergences among the extant fern orders all occurred prior to similar to 200 MYA. Finally, our species-tree inferences are congruent with analyses of concatenated data, but generally with lower support. Those cases where species-tree support values are higher than expected involve relationships that have been supported by smaller plastid datasets, suggesting that deep coalescence may be reducing support from the concatenated nuclear data. CONCLUSIONS: Our study demonstrates the utility of a curated phylogenomics approach to inferring fern phylogeny, and highlights the need to consider underlying data characteristics, along with data quantity, in phylogenetic studies.
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| 24. |
- Rothfels, Carl J., et al.
(författare)
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Transcriptome-Mining for Single-Copy Nuclear Markers in Ferns
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:10, s. e76957-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Molecular phylogenetic investigations have revolutionized our understanding of the evolutionary history of ferns-the second-most species-rich major group of vascular plants, and the sister clade to seed plants. The general absence of genomic resources available for this important group of plants, however, has resulted in the strong dependence of these studies on plastid data; nuclear or mitochondrial data have been rarely used. In this study, we utilize transcriptome data to design primers for nuclear markers for use in studies of fern evolutionary biology, and demonstrate the utility of these markers across the largest order of ferns, the Polypodiales. Principal Findings: We present 20 novel single-copy nuclear regions, across 10 distinct protein-coding genes: ApPEFP_C, cryptochrome 2, cryptochrome 4, DET1, gapCpSh, IBR3, pgiC, SQD1, TPLATE, and transducin. These loci, individually and in combination, show strong resolving power across the Polypodiales phylogeny, and are readily amplified and sequenced from our genomic DNA test set (from 15 diploid Polypodiales species). For each region, we also present transcriptome alignments of the focal locus and related paralogs-curated broadly across ferns-that will allow researchers to develop their own primer sets for fern taxa outside of the Polypodiales. Analyses of sequence data generated from our genomic DNA test set reveal strong effects of partitioning schemes on support levels and, to a much lesser extent, on topology. A model partitioned by codon position is strongly favored, and analyses of the combined data yield a Polypodiales phylogeny that is well-supported and consistent with earlier studies of this group. Conclusions: The 20 single-copy regions presented here more than triple the single-copy nuclear regions available for use in ferns. They provide a much-needed opportunity to assess plastid-derived hypotheses of relationships within the ferns, and increase our capacity to explore aspects of fern evolution previously unavailable to scientific investigation.
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| 25. |
- Rydin, Catarina, et al.
(författare)
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Evolutionary relationships in Ephedra (Gnetales), with implications for seed plant phylogeny
- 2009
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Ingår i: International journal of plant sciences. - : University of Chicago Press. - 1058-5893 .- 1537-5315. ; 170:8, s. 1031-1043
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Tidskriftsartikel (refereegranskat)abstract
- Evolutionary relationships in Ephedra are difficult to resolve, mainly because there are few informative characters in investigated loci and long distances to outgroups. We address these problems by using a large data set that includes information from seven plastid and nuclear loci and 204 vascular plants. The deepest divergences in Ephedra are weakly supported and differ by analytical method, but they indicate a basal grade of species distributed in the Mediterranean area. New World species are monophyletic, with a South American clade possibly nested within a North American clade. A mainly Asian clade comprises several well-supported subgroups, of which some are endemic to restricted geographic regions in East or Central Asia; others have a broad distribution that may extend into Europe (E. distachya, E. major) and/or Africa (E. pachyclada-E. somalensis). Ephedra laristanica and E. somalensis are nested within other species, whereas the recognition of E. milleri as a separate species is supported. Our results provide another example of how exceptionally difficult it is to disentangle the early divergences of seed plants. Bayesian analysis strongly supports the "gnetifer'' hypothesis, a result rarely found in the literature, but it conflicts with our results from only chloroplast data ("gne-cup'') and with results of most maximum parsimony analyses ("Gnetales sister'').
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| 26. |
- Schmidt, Alexander R., et al.
(författare)
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Selaginella in Cretaceous amber from Myanmar
- 2022
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Ingår i: Willdenowia. - : BioOne. - 0511-9618 .- 1868-6397. ; 52:2, s. 179-245
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Tidskriftsartikel (refereegranskat)abstract
- Selaginella (Selaginellales, Selaginellaceae) is the most speciose genus of lycophytes and, with approximately 750 recognized present-day species, also one of the largest genera of vascular plants. However, the evolutionary history of this species richness remains largely unresolved. Recent research suggests that Selaginella was diverse already in the mid-Cretaceous and shows that S. subg. Stachygynandrum dates back at least to the incipient Angiosperm Terrestrial Revolution some 100 million years ago. Here, we describe 20 new fossil-species of Selaginella based on fertile shoots and spores preserved in mid-Cretaceous Kachin amber from Myanmar and emend the previously described S. cretacea. Ten of the species (S. ciliifera, S. cretacea, S. grimaldii, S. heterosporangiata, S. longifimbriata, S. minutissima, S. ohlhoffiorum, S. patrickmuelleri, S. villosa, S. wangxinii) represent S. subg. Stachygynandrum because they possess anisophyllous strobili. The other eleven species have isophyllous strobili. Two of them (S. isophylla, S. wunderlichiana) are tentatively assigned to S. subg. Ericetorum, whereas the others (S. amplexicaulis, S. aurita, S. heinrichsii, S. konijnenburgiae, S. obscura, S. ovoidea, S. pellucida, S. tomescui, S. wangboi) cannot be placed into any fossil or extant subgenus. The fossils described in this study nearly duplicate the documented record of free-sporing plants from Kachin amber. The abundance and diversity of cryptogams, along with the absence of xerophytes among the taxa, is suggestive of constantly high humidity in the understory of the source forests of this amber.
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| 27. |
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| 28. |
- Schuettpelz, Eric, et al.
(författare)
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A community-derived classification for extant lycophytes and ferns
- 2016
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Ingår i: Journal of Systematics and Evolution. - : Wiley. - 1674-4918 .- 1759-6831. ; 54:6, s. 563-603
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Tidskriftsartikel (refereegranskat)abstract
- Phylogeny has long informed pteridophyte classification. As our ability to infer evolutionary trees has improved, classifications aimed at recognizing natural groups have become increasingly predictive and stable. Here, we provide a modern, comprehensive classification for lycophytes and ferns, down to the genus level, utilizing a community-based approach. We use monophyly as the primary criterion for the recognition of taxa, but also aim to preserve existing taxa and circumscriptions that are both widely accepted and consistent with our understanding of pteridophyte phylogeny. In total, this classification treats an estimated 11 916 species in 337 genera, 51 families, 14 orders, and two classes. This classification is not intended as the final word on lycophyte and fern taxonomy, but rather a summary statement of current hypotheses, derived from the best available data and shaped by those most familiar with the plants in question. We hope that it will serve as a resource for those wanting references to the recent literature on pteridophyte phylogeny and classification, a framework for guiding future investigations, and a stimulus to further discourse.
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| 29. |
- Schuettpelz, Eric, et al.
(författare)
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Plastid atpA data provide improved support for deep relationships among ferns
- 2006
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Ingår i: Taxon. - 0040-0262 .- 1996-8175. ; 55:4, s. 897-906
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Tidskriftsartikel (refereegranskat)abstract
- DNA sequence data and phylogenetic approaches have contributed greatly to our understanding of fern relationships. Nonetheless, the datasets analyzed to date have not been sufficient to definitively resolve all parts of the global fern phylogeny; additional data and more extensive sampling are necessary. Here, we explore the phylogenetic utility of the plastid atpA gene. Using newly designed primers, we obtained atpA sequences for 52 fern and 6 outgroup taxa, and then evaluated the capabilities of atpA relative to four other molecular markers, as well as the contributions of atpA in combined analyses. The five single-gene datasets differed markedly in the number of variable characters they possessed; and although the relationships resolved in analyses of these datasets were largely congruent, the robustness of the hypotheses varied considerably. The atpA dataset had more variable characters and resulted in a more robustly supported phylogeny than any of the other single gene datasets examined, suggesting that atpA will be exceptionally useful in more extensive studies of fern phylogeny and perhaps also in studies of other plant lineages. When the atpA data were analyzed in combination with the other four markers, an especially robust hypothesis of fern relationships emerged. With the addition of the atpA data, support increased substantially at several nodes; three nodes, which were not well-supported previously, received both good posterior probability and good bootstrap support in the combined 5-gene (> 6 kb) analyses.
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| 30. |
- Smith, Alan R., et al.
(författare)
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16. Fern classification
- 2008
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Ingår i: Biology and evolution of ferns and lycophytes. - : Cambridge University Press, Cambridge. - 9780521874113
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 31. |
- Smith, Alan R., et al.
(författare)
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A classification for extant ferns
- 2006
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Ingår i: Taxon. - 0040-0262 .- 1996-8175. ; 55:3, s. 705-731
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Forskningsöversikt (refereegranskat)abstract
- We present a revised classification for extant ferns, with emphasis on ordinal and familial ranks, and a synopsis of included genera. Our classification reflects recently published phylogenetic hypotheses based on both morphological and molecular data. Within our new classification, we recognize four monophyletic classes, 11 monophyletic orders, and 37 families, 32 of which are strongly supported as monophyletic. One new family, Cibotiaceae Korall, is described. The phylogenetic affinities of a few genera in the order Polypodiales are unclear and their familial placements are therefore tentative. Alphabetical lists of accepted genera (including common synonyms), families, orders, and taxa of higher rank are provided.
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| 32. |
- Smith, Alan R., et al.
(författare)
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Selaginella pectinata resurrected : The correct name for an unusual endemic spikemoss from Madagascar
- 2016
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Ingår i: American Fern Journal. - : American Fern Society. - 0002-8444 .- 1938-422X. ; 106:2, s. 131-134
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Tidskriftsartikel (refereegranskat)abstract
- We review the nomenclature of Selaginella polymorpha Badre, endemic to Madagascar, and conclude that this name is illegitimate by superfluity under the International Code of Nomenclature. The name should be rejected and replaced by the older S. pectinata Spring, coined in 1843.
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| 33. |
- Weststrand, Stina, et al.
(författare)
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A subgeneric classification of Selaginella (Selaginellaceae)
- 2016
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Ingår i: American Journal of Botany. - : Wiley. - 0002-9122 .- 1537-2197. ; 103:12, s. 2160-2169
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Tidskriftsartikel (refereegranskat)abstract
- PREMISE OF THE STUDY: The lycophyte family Selaginellaceae includes approximately 750 herbaceous species worldwide, with the main species richness in the tropics and subtropics. We recently presented a phylogenetic analysis of Selaginellaceae based on DNA sequence data and, with the phylogeny as a framework, the study discussed the character evolution of the group focusing on gross morphology. Here we translate these findings into a new classification.METHODS: To present a robust and useful classification, we identified well-supported monophyletic groups from our previous phylogenetic analysis of 223 species, which together represent the diversity of the family with respect to morphology, taxonomy, and geographical distribution. Care was taken to choose groups with supporting morphology.KEY RESULTS: In this classification, we recognize a single genus Selaginella and seven subgenera: Selaginella, Rupestrae, Lepidophyllae, Gymnogynum, Exaltatae, Ericetorum, and Stachygynandrum. The subgenera are all well supported based on analysis of DNA sequence data and morphology. A key to the subgenera is presented.CONCLUSIONS: Our new classification is based on a well-founded hypothesis of the evolutionary relationships of Selaginella, and each subgenus can be identified by a suite of morphological features, most of them possible to study in the field. Our intention is that the classification will be useful not only to experts in the field, but also to a broader audience.
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| 34. |
- Weststrand, Stina, et al.
(författare)
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Biogeography lacks some spores. Spikemosses don't : Phylogeny, historical biogeography and phylogeography of Selaginella
- 2011
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Studying biogeography in a broad range of lineages is needed to pose general biogeographical hypotheses. However, plant biogeography studies have so far mainly focused on seed plants, and few have targeted plants that are dispersed by spores. In my PhD project I use the lycophyte family Selaginellaceae (spikemosses) as the study organism. The family has an origin in the Late Carboniferous, and it comprises the single genus Selaginella with approximately 700 species. The main species distribution is throughout subtropical and tropical areas, even though some ten percent of the species diversity is found in temperate regions. In contrast to most other spore dispersed plants, Selaginella is heterosporous meaning that two kinds of spores are produced, mega- and microspores. The spores give rise to a female and male gametophyte, respectively, implying that intragametophytic selfing is not possible. How does this affect the plants' ability to disperse?The main focus of my studies lies on the occurrence of long-distance dispersal on different temporal, spatial, and phylogenetic scales in Selaginella. The first part of the project addresses the question if the disjunct distributions seen in Selaginella are due to long-distance dispersal or historical vicariance events. To start with, I will focus on historical biogeography in the family Selaginellaceae as a whole, and evaluate possible vicariance scenarios as a response to the breakup of Gondwana. Subsequently, studies on a more regional scale will be conducted by investigating biogeographical patterns in a well-supported group of taxa in Southeast Asia/Australasia. This is a region with extensive land mass changes due to, among other events, the collision between India and Asia in the Eocene, and sea level fluctuations. The second part of the project will be conducted at the intraspecific level. I will test if any phylogeographical patterns are discernable in Selaginella, and the main study object will be the single Swedish species, Selaginella selaginoides. Overall my PhD project aims to give us new insights into which impact long-distance dispersal has in shaping the biogeography of spore dispersed plants.
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| 35. |
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| 36. |
- Weststrand, Stina, et al.
(författare)
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Phylogeny of Selaginellaceae : There is value in morphology after all!
- 2016
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Ingår i: American Journal of Botany. - : Wiley. - 0002-9122 .- 1537-2197. ; 103:12, s. 2136-2159
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Tidskriftsartikel (refereegranskat)abstract
- PREMISE OF THE STUDY: The cosmopolitan lycophyte family Selaginellaceae, dating back to the Late Devonian–Early Carboniferous, is notorious for its many species with a seemingly undifferentiated gross morphology. This morphological stasis has for a long time hampered our understanding of the evolutionary history of the single genus Selaginella. Here we present a large-scale phylogenetic analysis of Selaginella, and based on the resulting phylogeny, we discuss morphological evolution in the group.METHODS: We sampled about one-third of the approximately 750 recognized Selaginella species. Evolutionary relationships were inferred from both chloroplast (rbcL) and single-copy nuclear gene data (pgiC and SQD1) using a Bayesian inference approach. The morphology of the group was studied and important features mapped onto the phylogeny.KEY RESULTS: We present an overall well-supported phylogeny of Selaginella, and the phylogenetic positions of some previously problematic taxa (i.e., S. sinensis and allies) are now resolved with strong support. We show that even though the evolution of most morphological characters involves reversals and/or parallelisms, several characters are phylogenetically informative. Seven major clades are identified, which each can be uniquely diagnosed by a suite of morphological features. There is value in morphology after all!CONCLUSIONS: Our hypothesis of the evolutionary relationships of Selaginella is well founded based on DNA sequence data, as well as morphology, and is in line with previous findings. It will serve as a firm basis for further studies on Selaginella with respect to, e.g., the poorly known alpha taxonomy, as well as evolutionary questions such as historical biogeographic reconstructions.
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| 37. |
- Weststrand, Stina, et al.
(författare)
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Selaginellaceae and its historical biogeography : How can the disjunct distributions seen today be explained?
- 2014
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Selaginellaceae, spikemosses, is a large family of lycophytes comprising approximately 700 species spread mainly across the tropics and subtropics. The family is interesting in many aspects, not the least since it has an origin in the Early Carboniferous (ca. 345 Ma), which makes it an important key for understanding the early evolution of vascular plants. In contrast to most other spore-dispersed plants, spikemosses are heterosporous. Thus, sperm and egg cells are produced by separate gametophytes that develop from micro- and megaspores, respectively. This may have implications for the plants’ ability to disperse, and studying dispersal and distribution patterns in Selaginellaceae can give us important contributions towards a broader understanding of plant dispersal biology.In this study, we present the first large-scale phylogeny of Selaginellaceae. We have assembled a dataset of both plastid and nuclear markers for approximately 200 species of Selaginella, making up for almost one third of the species diversity known today. The resulting phylogeny gives us many new insights into the evolutionary history of Selaginellaceae, and in particular it helps us make hypotheses about the historical biogeography of the family. Are for example the disjunct distributions seen in Selaginellaceae the result of historical vicariance events or long-distance dispersals?
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| 38. |
- Weststrand, Stina, 1987-
(författare)
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Spikemoss patterns : Systematics and historical biogeography of Selaginellaceae
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Selaginellaceae, spikemosses, is a heterosporous plant family belonging to the lycophytes. With an estimated age of some 350 million years, the family is historically important as one of the oldest known groups of vascular plants. Selaginellaceae is herbaceous with a worldwide distribution. However, the majority of the ca. 750 species in the single genus Selaginella are found in the tropics and subtropics.This thesis aims at elucidating the systematics and historical biogeography of Selaginellaceae. The evolutionary relationships of the family were inferred from DNA sequence data (plastid and single-copy nuclear) of one-third of the species richness in the group. Attention was paid to cover the previously undersampled taxonomic, morphological, and geographical diversity. Morphological features were studied and mapped onto the phylogeny. The results show an overall well-supported phylogeny and even more complex morphological patterns than previously reported. Despite this, many clades can be distinguished by unique suites of morphological features.With the phylogeny as a basis, together with the thorough morphological studies, a new subgeneric classification with seven subgenera, representing strongly supported monophyletic groups, is presented for Selaginella. By mainly using gross morphological features, easily studied by the naked eye or with a hand lens, the intention is that the classification should be useful to a broader audience.During the work with species determinations, it was revealed that the correct name for an endemic Madagascan Selaginella species is S. pectinata Spring, not S. polymorpha Badré as previously proposed.The robust phylogeny of Selaginellaceae allowed for a historical biogeographical analysis of the group. A time-calibrated phylogeny, together with extant species distribution data, formed the basis. The results show pre-Pangean diversification patterns, Gondwanan vicariance, and more recent Cenozoic long-distance dispersals. The many inferred transoceanic dispersals during the last 50 million years are surprising considering Selaginella’s large megaspores that are thought to have a negative effect on dispersal.In conclusion, this thesis presents a well-founded hypothesis of the evolutionary history of Selaginellaceae including its phylogeny, morphology, and historical biogeography. The thesis forms a firm basis for further studies on Selaginellaceae in particular, and gives us a better understanding of early land plant evolution in general.
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| 39. |
- Weststrand, Stina, et al.
(författare)
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There seems to be some morphology there after all! : Interpreting morphology in Selaginella in the context of phylogeny
- 2015
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The lycophyte family Selaginellaceae, with its single genus Selaginella, has long been considered a problematic family with few distinguishable morphological characters when it comes to recognizing subgroups. Several morphology-based classifications have been proposed, but phylogenetic analyses based on DNA sequence data have later shown that these classifications poorly reflect the evolutionary history of the group.Are there undiscovered morphological patterns in Selaginella? We have increased the sampling from previous molecular work to include data from both chloroplast and nuclear markers for more than one third of the 700 Selaginella species found worldwide. We here present a robust large-scale phylogeny that, together with a thorough review of the group's morphology, serves as a reference for a new subgeneric classification of Selaginella.
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| 40. |
- Weststrand, Stina, et al.
(författare)
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What can a new large-scale phylogeny of Selaginellaceae tell us?
- 2012
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Selaginellaceae, spikemosses, are a large family of lycophytes comprising approximately 700 species spread mainly across the tropics and subtropics. The family is interesting in many aspects, not the least since it has an origin in the Early Carboniferous (ca. 345 Ma), which makes it an important key for understanding the early evolution of vascular plants. In contrast to most other spore dispersed plants, Selaginellaceae are heterosporous, meaning that both megaspores and microspores are needed for reproduction. This might have implications for the plants’ ability to disperse, and studying dispersal and distribution patterns in Selaginellaceae can give us important contributions towards a broader understanding of plant dispersal biology.All evolutionary questions have to be put into a phylogenetic framework, and up to now no larger phylogeny of Selaginellaceae has been made. In this study a dataset of approximately 200 species of Selaginella has been assembled, making up for almost one third of the diversity known today. The resulting phylogeny gives us many new insights about the evolutionary history of Selaginellaceae, and in particular it helps us make hypotheses about the historical biogeography of the family. Is for example the disjunct distribution of Selaginellaceae a result of historical vicariance events or long-distance dispersal?
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| 41. |
- Weststrand, Stina, et al.
(författare)
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What have the spikemosses been up to during the last 350 million years?
- 2013
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The spikemosses, or the lycophyte family Selaginellaceae, have been around for about 350 million years and today they have a worldwide distribution. They are dispersed by spores and little is known about their dispersal and distribution patterns. As an example of a heterosporous plant, where two different kinds of spores are needed for reproduction, the spikemosses make up an interesting study system for plant dispersal biology. Is long-distance dispersal common in the group, or are disjunct distributions mainly a result of historical vicariance events? What can a large‐scale phylogeny and biogeographical analyses tell us?
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