| 1. |
- Aagaard, Sunniva M.D. 1977-, et al.
(författare)
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Resolving maternal relationships in the clubmoss genus Diphasiastrum (Lycopodiaceae)
- 2009
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Ingår i: Taxon. - 0040-0262 .- 1996-8175. ; 58:3, s. 835-848
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Tidskriftsartikel (refereegranskat)abstract
- Diphasiastrum comprises 20-30 species. In addition to a number of species with a circumboreal distribution, several island endemics and putative diploid hybrid species contribute to the diversity of the group. To assess the integrity and relationships of the recognized species, a global phylogeny of Diphasiastrum is constructed using five chloroplast regions comprising ~9000 bp. Six monophyletic groups are identified. Accessions identified as hybrid species cluster in all but one case together with one of its putative parents. Two microsatellite loci are identified, and allelic information combined with sequence information is found diagnostic for the three putative parental taxa in the Central Europe hybrid complexes. Haplotype screening is performed on six Central European populations, from where one or more putative diploid hybrid species have been reported to grow in sympatry with their parent species. The most common parental haplotypes are identified in all populations. Additional intraspecific variation, restricted to single populations, is identified in all sympatric populations at very low frequencies. Taking the low degree of sequence and microsatellite variation into consideration, the acknowledged morphological diversity in Central Europe is probably best explained by phenotypic plasticity, ancestral polymorphisms or relatively recent events of reticulate evolution.
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| 2. |
- Andreasen, Katarina, et al.
(författare)
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Successful DNA amplification of a more than 200-year-old herbarium specimen : recovering genetic material from the Linnaean era
- 2009
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Ingår i: Taxon. - 0040-0262 .- 1996-8175. ; 58:3, s. 959-962
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Tidskriftsartikel (refereegranskat)abstract
- The limit for successful DNA extraction was tested by amplification and sequencing of an over 200-year-old herbarium specimen collected by Adam Afzelius, a student of Carl Linnaeus. We amplified and sequenced a 800-bp region between 16S ribosomal DNA and the 3′ part of the trnI gene (16S-trnI) in the chloroplast genomeof Phaulopsis talbotii S. Moore (Acanthaceae). To test the replicability and to control for contamination the procedure was performed in sealed vials and with negative PCR controls. The procedure was also repeated in a separate laboratory. In addition, the chloroplast rpl16 intron was successfully amplified and sequenced and the rps16 intron amplified. Sequences of taxa closely related to Acanthaceae were found to be most similar to the produced sequences. The results suggest that molecular investigations of other 18th century botanical collections are feasible and that molecular methods could be employed for comparative studies to extant plant collections. An important application would be to identify descendants or clones of Linnaean lectotypes by comparing DNA from these with potentially remnant plants from Linnaeus’ cultivations.
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| 3. |
- Backlund, Maria, et al.
(författare)
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Paraphyly of Paederieae, recognition of Putorieae and expansion of Plocama (Rubiaceae-Rubioideae)
- 2007
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Ingår i: Taxon. - 0040-0262 .- 1996-8175. ; 56:2, s. 315-328
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Tidskriftsartikel (refereegranskat)abstract
- Phylogenetic analyses of taxa that have been included in the tribe Paederieae are performed on the basis of a molecular dataset of plastid DNA sequences (the rbcL gene, rps16 intron, and the regions trnT-F). The paraphyly of Paederieae as currently circumscribed is confirmed. A clade comprising Paederia, Spermadictyon, Leptodermis, and Serissa is retrieved and the circumscription of Paederieae is proposed to be restricted to this clade. Paederia is sister to a clade with Spermadictyon, Leptodermis, and Serissa. Paederia is subdivided into an Asian and an African clade, and within the African clade seven species endemic to Madagascar are sister to P. pospischilii in north-eastern Africa. The position of Kelloggia as sister to Rubieae is confirmed and a position of Saprosma in the Spermacoceae alliance is supported. The genera Putoria, Gaillonia (with segregates), Plocama, and Aitchisonia form a clade that is sister to Theligoneae/Kelloggia/Rubieae. The name Putorieae is resurrected for the members of this clade. A synopsis of Putorieae is provided, where all species are placed in an expanded Plocama with 34 species. Thirty-one new combinations in Plocama are proposed. Plocama pendula on the Canary Islands is strongly supported as sister to a clade with P. crocyllis (former Crocyllis) in southern Africa and P. yemenensis and P. tinctoria (former Gaillonia) in southern Arabia/Horn of Africa.
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| 4. |
- Backlund, Maria, et al.
(författare)
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Revision of the Mediterranean species of Plocama (Rubiaceae)
- 2007
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Ingår i: Taxon. - 0040-0262 .- 1996-8175. ; 56:2, s. 516-520
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Tidskriftsartikel (refereegranskat)abstract
- The Mediterranean species of Plocama (incl. Putoria) are revised and two species, the widespread P. calabrica, comb. nov., and P. brevifolia, comb. nov., in Morocco and Algeria, are recognized. The variation and circumscription of the species are discussed and distribution maps are provided. Several names are reduced to synonymy and seven lectotypes are designated.
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| 5. |
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| 6. |
- Elbrächter, Malte, et al.
(författare)
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Establishing an Agenda for Calcareous Dinoflagellate Research (Thoracosphaeraceae, Dinophyceae) including a nomenclatural synopsis of generic names
- 2008
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Ingår i: Taxon. - 0040-0262 .- 1996-8175. ; 57:4, s. 1289-1303
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Tidskriftsartikel (refereegranskat)abstract
- Calcareous dinoflagellates are considered to be a monophyletic group of peridinoid taxa that have the potential to produce calcified exoskeletal structures during the life cycle, or that derive from such forms. Frequently, these calcareous bodies are excellently preserved in the fossil record and have received increased attention during the past three decades with regard to their use in biostratigraphy, climate and environmental reconstruction. Fossil and extant taxa have been classified in various, partly concurring, systematic concepts, using character complexes of the theca, cyst wall ultrastructure and archaeopyle/operculum morphology. The significance of such character complexes is briefly discussed in the light of molecular data that have been accumulated during the past decade. Over the years, the number of published taxonomic names has increased, partly due to nomenclatural changes. We propose that the entirety of calcareous dinoflagellates, and non-calcareous relatives derived from them, is accommodated in a single family of the order Peridiniales, the Thoracosphaeraceae, combining the former segregated taxonomic units Calciodinelloideae, a subfamily within Peridiniaceae, and Thoracosphaerales, a separate dinoflagellate order. As a result of a meeting of calcareous dinoflagellate specialists, we outline major subjects that are in need of re-investigation and -evaluation (an Agenda for Calcareous Dinoflagellate Research). In order to contribute to a consistent and stable nomenclature and taxonomy of calcareous dinoflagellates, we list 97 published generic names assigned to known calcareous dinoflagellates in a nomenclatural synopsis, with species names indicating their types and information on type locality and stratigraphy. We evaluate the status of these names—whether validly published and, if so, whether legitimate—,a crucial first step for any revisionary work in the future.
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| 7. |
- Frajman, Božo, et al.
(författare)
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Phylogenetic relationships of Atocion and Viscaria (Sileneae, Caryophyllaceae) inferred from chloroplast, nuclear ribosomal, and low-copy gene DNA sequences
- 2009
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Ingår i: Taxon. - 0040-0262 .- 1996-8175. ; 58:3, s. 811-824
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Tidskriftsartikel (refereegranskat)abstract
- Atocion and Viscaria are two of seven small genera recognised in the tribe Sileneae on the basis of molecular phylogenies. The aim of the present study is to infer phylogenetic relationships among their subordinate taxa, using chloroplast (rps16 intron,psbE-petG spacer region) and nuclear (ITS and the RNA polymerase gene family) DNA sequences. Relative dating was used to discriminate among intralineage and interlineage processes that cause incongruence among different gene-tree topologies. Atocion asterias is demonstrated to belong to Viscaria, which contains three species: V vulgaris (incl. V atropurpurea), V alpina, and V asterias. Infraspecific differentiation of V alpina is not supported by the sequence data. The traditional sectional delimitation of Atocion taxa within Silene is not supported phylogenetically, and Silene tatarinowii as well as S. hoefftiana do not belong to Atocion, as classified previously. Atocion contains six species: A. armeria, A. compactum, A. lerchenfeldianum, A. reuterianum, A. rupestre, and A. scythicinum (not included in our study). With this circumscription, Atocion and Viscaria, respectively, form monophyletic groups in the cpDNA, ITS, RPD2a and RPD2b trees, but not in the RPA2 tree, where such relationships were possibly distorted by ancient hybridisation. Hybridisation with subsequent chloroplast capture is likely to have taken place in the evolutionary history of A. compactum. Three novel nomenclatural combinations are made: Atocion reuterianum, A. scythicinum and Viscaria asterias.
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| 10. |
- Gueidan, Cecile, et al.
(författare)
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Generic classification of the Verrucariaceae (Ascomycota) based on molecular and morphological evidence : recent progress and remaining challenges
- 2009
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Ingår i: Taxon. - 0040-0262 .- 1996-8175. ; 58:1, s. 184-208
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Forskningsöversikt (refereegranskat)abstract
- Recent molecular phylogenetic analyses and morphological Studies have shown that it is necessary to revise the present morphology-based generic delineation of the lichen family Verrucariaceae in order to account for evolutionary relatedness between species. Consequently, several genera were recently described or resurrected, and others were re-circumscribed. As an additional step toward this generic revision, three new genera (Hydropunctaria, Parabagliettoa, Wahlenbergiella) and eleven new combinations are proposed here. A summary of the Current taxonomic and morphological circumscription of all genera investigated so far is also presented. Several monophyletic groups are identified for which further taxonomical changes will be required, but for which taxon and gene sampling is presently viewed as insufficient. Clear morphological synapomorphies were found to be rare for newly delimited genera. In some cases (reduced morphology or plesiomorphism), even the combinations of slightly homoplasious phenotypic characters do not allow a clear morphological generic circumscription. Molecular features are envisioned as characters for delimiting these taxa.
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