Phylogeny of Cobaea (Polemoniaceae) Based on Sequence Data from the ITS Region of Nuclear Ribosomal DNA

1998 ◽  
Vol 23 (1) ◽  
pp. 57 ◽  
Author(s):  
L. Alan Prather ◽  
Robert K. Jansen
Keyword(s):  
Ribosomal Dna ◽  
Sequence Data ◽  
Its Region ◽  
Nuclear Ribosomal Dna

Phylogeny of Sisymbrium (Brassicaceae) based on ITS sequences of nuclear ribosomal DNA

2002 ◽  
Vol 80 (9) ◽  
pp. 1002-1017 ◽  
Author(s):  
Suzanne I Warwick ◽  
Ihsan A Al-Shehbaz ◽  
Robert A Price ◽  
Connie Sauder
Keyword(s):  
Ribosomal Dna ◽  
New World ◽  
Sequence Data ◽  
Its Region ◽  
Internal Transcribed Spacers ◽  
Nuclear Ribosomal Dna ◽  
Maximum Parsimony Analysis ◽  
Rrna Gene ◽  
Old World ◽  
5.8S Rrna Gene

The genus Sisymbrium as currently circumscribed includes about 94 species disjunctly distributed in the Old (41 spp.) and the New World (53 spp.). Sisymbrium has been variously delimited, with several segregate genera proposed (subtribe Sisymbriinae) primarily for the new World taxa, including Schoenocrambe, Coelophragmus, and Mostacillastrum. Using sequence data from the internal transcribed spacers of nuclear ribosomal DNA and the 5.8S rRNA gene (collectively, ITS region), we examined the evolutionary relationships of Old and New World Sisymbrium species with its segregate genera and the validity of O.E. Schulz's classical sectional treatment of Sisymbrium. Sequence data were obtained from 33 Sisymbrium species, representing all 14 sections and two Sisymbrium species formerly assigned to segregate genera Coelophragmus and Mostacillastrum (subtribe Sisymbriinae), and two putative Sisymbrium species currently assigned to Neotorularia. Sequence data were also obtained from 26 taxa from segregate or related genera includingSchoenocrambe, Werdermannia (subtribe Sisymbriinae), eight genera in the Thelypodieae, Sibara (tribe Arabideae) and Pringlea (tribe Pringleeae), four members of the tribe Brassiceae, and three other Neotorularia species. Results from maximum parsimony analysis showed a polyphyletic origin for Sisymbrium and did not correspond well to Schulz's sectional classification. Sisymbrium species were split into three major clades: Old World Sisymbrium (including Neotorularia aculeolata, Neotorularia afghanica, and the type species of Schoenocrambe, Schoenocrambe linifolia, the sole New World member of this Old World clade); New World Sisymbrium (along with the remaining New World taxa) and designated as the New World Thelypodieae alliance; and the tribe Brassiceae ( including Sisymbrium supinum and Sisymbrium thellungii).Key words: Sisymbrium, Schoenocrambe, ITS, Thelypodieae, taxonomy, Brassicaceae.

Higher-level relationships among the eucalypts are resolved by ITS-sequence data

2002 ◽  
Vol 15 (1) ◽  
pp. 49 ◽  
Author(s):  
Dorothy A. Steane ◽  
Dean Nicolle ◽  
Gay E. McKinnon ◽  
René E. Vaillancourt ◽  
Brad M. Potts
Keyword(s):  
Internal Transcribed Spacer ◽  
Sequence Data ◽  
Its Region ◽  
Molecular Data ◽  
Nuclear Ribosomal Dna ◽  
Its Sequence ◽  
Phylogenetic Groups ◽  
Single Section ◽  
Western Australian ◽  
Genus Eucalyptus

This expanded survey of ITS sequences represents the largest analysis of molecular data ever attempted on Eucalyptus. Sequences of the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA were included in an analysis of 90 species of Eucalyptus s.s. and 28 species representing eight other genera (Allosyncarpia, Angophora, Arillastrum, Corymbia, Eucalyptopsis, Stockwellia, Lophostemon and Metrosideros). The results of the study indicate that Angophora and Corymbia form a well-supported clade that is highly differentiated from Eucalyptus s.s. Corymbia species are divided between two clades, one of which may be the sister to Angophora. Allosyncarpia, Arillastrum, Eucalyptopsis and ‘Stockwellia’ are also highly differentiated from Eucalyptus s.s. If the genus Eucalyptus is to be expanded to include Angophora and Corymbia(sensu Brooker 2000), ITS data suggest that Allosyncarpia, Eucalyptopsis, ‘Stockwellia’ and potentially Arillastrum should also be included in Eucalyptus s.l. The ITS data suggest that subg. Symphyomyrtus is paraphyletic and that subg. Minutifructus should be included within it. Within subg.Symphyomyrtus, only sect. Maidenaria appears to be monophyletic. Sections Adnataria and Dumaria are probably monophyletic; sections Exsertaria and Latoangulatae are very close and probably should be combined in a single section. Section Bisectae is polyphyletic and is divided into two distinct lineages. The phylogenetic groups depicted by ITS data are consistent with the frequency of natural inter-specific hybridisations as well as data from controlled crosses within subgenus Symphyomyrtus. The ITS data illustrate that subg. Idiogenes and western Australian monocalypts are early evolutionary lines relative to E. diversifolia, E. rubiginosa (monotypic subg. Primitiva) and the eastern monocalypts and that subg. Primitiva should be sunk into subg. Eucalyptus. Subgenus Eudesmia may be monophyletic, grouping with subgenera Idiogenes and Eucalyptus. Further work is required to confirm the phylogenetic positions of the monotypic subgenera Alveolata, Cruciformes, Acerosae and Cuboidea.

Synonymy of the three Villaria Rolfe species (Rubiaceae): evidence from morphological and nuclear ribosomal DNA sequence data

Acta Manilana ◽  
2010 ◽  
Vol 56 (0) ◽  
Author(s):  
GJD Alejandro ◽  
DLA Arlegui ◽  
PMO Detabali ◽  
EA Espino ◽  
EG Layson ◽  
...  
Keyword(s):  
Dna Sequence ◽  
Ribosomal Dna ◽  
Sequence Data ◽  
Nuclear Ribosomal Dna ◽  
Dna Sequence Data ◽  
Ribosomal Dna Sequence

Phylogenetic position of Arabis arenicola and generic limits of Aphragmus and Eutrema (Brassicaceae) based on sequences of nuclear ribosomal DNA

2006 ◽  
Vol 84 (2) ◽  
pp. 269-281 ◽  
Author(s):  
Suzanne I. Warwick ◽  
Ihsan A. Al-Shehbaz ◽  
Connie A. Sauder
Keyword(s):  
Internal Transcribed Spacer ◽  
Sequence Data ◽  
Its Region ◽  
Molecular Data ◽  
The Other ◽  
Nuclear Ribosomal Dna ◽  
Phylogenetic Position ◽  
New Combinations ◽  
Arabidopsis Lyrata ◽  
Relationship Of

Sequence data from the nuclear ribosomal internal transcribed spacer (ITS) region of 45 taxa were used to determine the phylogenetic relationship of Arabis arenicola to Arabis , Arabidopsis , Braya , and Eutrema , and that of Eutrema to the purportedly related genera Aphragmus , Lignariella , Neomartinella , Platycraspedum , Taphrospermum , and Thellungiella . Arabis arenicola was originally described as Eutrema in 1830, transferred to Arabis in 1898, and has remained in Arabis to the present, even though it is morphologically more similar to Arabidopsis, Braya, and Eutrema. Sequence data were obtained from representative taxa of Arabis, Arabidopsis, and related Boechera and Catolobus, Braya and Neotorularia, and Eutrema, Aphragmus, Lignariella, Neomartinella, Platycraspedum, Taphrospermum, and Thellungiella. The five Arabis arenicola accessions examined had ITS sequences that were identical to each other and to four Arabidopsis lyrata accessions. In both maximum parsimony and maximum likelihood analyses, Arabis arenicola fell within the Arabidopsis clade and was closely aligned with Arabidopsis lyrata. Two of six purportedly related genera were not closely related to Eutrema. Both analyses placed Lignariella within a separate well-supported clade with Aphragmus, while the other four genera, Neomartinella, Platycraspedum, Taphrospermum, and Thellungiella, fell within a well-supported clade with Eutrema. Morphology and molecular data strongly suggest transferring Arabis arenicola to Arabidopsis, expanding Aphragmus to include Lignariella, and expanding Eutrema to include Neomartinella, Platycraspedum, Taphrospermum, and Thellungiella. New combinations in Arabidopsis and Aphragmus are proposed.

Peucedanum huangshanense (Apiaceae), a new species from Anhui, China

Phytotaxa ◽  
2020 ◽  
Vol 430 (1) ◽  
pp. 17-24
Author(s):  
SHAN-SHAN CHU ◽  
DE-QUN WANG ◽  
HUA-SHENG PENG ◽  
LU-QI HUANG
Keyword(s):  
New Species ◽  
Ribosomal Dna ◽  
Internal Transcribed Spacer ◽  
Its Region ◽  
Distinct Species ◽  
Nuclear Ribosomal Dna ◽  
Phylogenetic Position ◽  
A New Species

Peucedanum huangshanense, a new species discovered in Anhui, China, is illustrated and described. Detailed morphological comparisons have showed that it is similar to P. praeruptorum but differs from the latter by having larger compound umbels (5–14 cm across), rays up to 25, and long-ovoid mericarps with lateral ribs narrowly winged. To explore the phylogenetic position of this species, nuclear ribosomal DNA internal transcribed spacer (ITS) region was sequenced for P. huangshanense and P. praeruptorum collected in different places. The morphological and molecular evidences support the hypothesis that P. huangshanense is a new distinct species.

scholarly journals Characterizing the ribosomal tandem repeat and its utility as a DNA barcode in lichen-forming fungi

2019 ◽  
Author(s):  
Michael Bradshaw ◽  
Felix Grewe ◽  
Anne Thomas ◽  
Cody H. Harrison ◽  
Hanna Lindgren ◽  
...  
Keyword(s):  
Species Complex ◽  
High Throughput Sequencing ◽  
Sequence Data ◽  
Dna Barcode ◽  
Intergenic Spacer ◽  
Its Region ◽  
Nuclear Ribosomal Dna ◽  
Nucleotide Position ◽  
Ribosomal Operon ◽  
Intragenomic Variation

Abstract Background: Regions within the nuclear ribosomal operon are a major tool for inferring evolutionary relationships and investigating diversity in fungi. In spite of the prevalent use of ribosomal markers in fungal research, central features of nuclear ribosomal DNA (nrDNA) evolution are poorly characterized for fungi in general, including lichenized fungi. The internal transcribed spacer (ITS) region of the nrDNA has been adopted as the primary DNA barcode identification marker for fungi. However, little is known about intragenomic variation in the nrDNA in symbiotic fungi. In order to better understand evolution of nrDNA and the utility of the ITS region for barcode identification of lichen-forming fungal species, we generated nearly complete nuclear ribosomal operon sequences from nine species in the Rhizoplaca melanophthalma species complex using short reads from high-throughput sequencing. Results: We estimated copy numbers for the nrDNA operon, ranging from nine to 48 copies for members of thiscomplex, and found low levels of intragenomic variation in the standard barcode region (ITS). Monophyly of currently described species in this complex was supported in phylogenetic inferences based on the ITS, 28S, IGS, and some intronic regions; however, a phylogenetic inference based on the 18S provided much lower resolution. Phylogenetic analysis of concatenated ITS and intergenic spacer sequence data generated from 496 specimens collected worldwide revealed previously unrecognized lineages in the nrDNA phylogeny. Conclusions: The results from our study support the general assumption that the ITS region of the nrDNA is an effective barcoding marker for fungi. For the R. melanophthalma group, the limited amount of potential intragenomic variability in the ITS region did not correspond to fixed diagnostic nucleotide position characters separating taxa within this species complex. Previously unrecognized lineages inferred from ITS sequence data may represent undescribed species-level lineages or reflect uncharacterized aspects of nrDNA evolution in the R. melanophthalma species complex.

scholarly journals DNAbased detection of western gall rust

2004 ◽  
Vol 57 ◽  
pp. 146-150 ◽  
Author(s):  
T.D. Ramsfield ◽  
D.R. Vogler
Keyword(s):  
Ribosomal Dna ◽  
Internal Transcribed Spacer ◽  
Rust Fungus ◽  
Its Region ◽  
Pcr Primers ◽  
Host Tissue ◽  
Nuclear Ribosomal Dna ◽  
Infected Host ◽  
The Novel ◽  
Pcr Product

The internal transcribed spacer (ITS) region of the nuclear ribosomal DNA of the western gall rust fungus (Peridermium harknessii) was amplified using the basidiomycetespecific PCR primers ITS1F and ITS4B The PCR product was then sequenced and aligned with other pine stem rust ITS sequences and a conserved region within P harknessii was targeted with the novel PCR primer Phar1 Our PCR protocol was able to differentiate P harknessii from Cronartium comandrae and C coleosporioides and detected P harknessii within infected host tissue However P harknessii was not distinguishable from C quercuum fsp fusiforme The method provides a rapid and sensitive detection protocol for P harknessii and C quercuum fsp fusiforme within infected host tissue

scholarly journals Characterizing the ribosomal tandem repeat and its utility as a DNA barcode in lichen-forming fungi

2019 ◽  
Author(s):  
Michael Bradshaw ◽  
Felix Grewe ◽  
Anne Thomas ◽  
Cody H. Harrison ◽  
Hanna Lindgren ◽  
...  
Keyword(s):  
Species Complex ◽  
Sequence Data ◽  
Dna Barcode ◽  
Intergenic Spacer ◽  
Its Region ◽  
Nuclear Ribosomal Dna ◽  
Nucleotide Position ◽  
Phylogenetic Reconstructions ◽  
Ribosomal Operon ◽  
Intragenomic Variation

Abstract Background Regions within the nuclear ribosomal operon are a major tool for inferring evolutionary relationships and investigating diversity in fungi. In spite of the prevalent use of ribosomal markers in fungal research, central features of nuclear ribosomal DNA (nrDNA) evolution are poorly characterized for fungi in general, including lichenized fungi. The internal transcribed spacer (ITS) region of the nrDNA has been adopted as the primary DNA barcode identification marker for fungi. However, little is known about intragenomic variation in the nrDNA in symbiotic fungi. In order to better understand evolution of nrDNA and the utility of the ITS region for barcode identification of lichen-forming fungal species, we generated nearly complete nuclear ribosomal operon sequences from approximate nine species in the Rhizoplaca melanophthalma species complex using short reads from high-throughput sequencing.Results We estimated copy numbers for the nrDNA operon, ranging from nine to 48 copies for members of this complex, and found low levels of intragenomic variation in the standard barcode region (ITS). Monophyly of currently described species in this complex was supported in phylogenetic reconstructions of the ITS, 28S, IGS, and some intronic regions; however, phylogenetic reconstructions based on the 18S provided much lower resolution. Phylogenetic analysis of concatenated ITS and intergenic spacer sequence data generated from 496 specimens collected worldwide revealed, previously unrecognized lineages in the nrDNA phylogeny.Conclusions The results from our study support the general assumption that the ITS region of the nrDNA is an effective barcoding marker for fungi. For the R. melanophthalma group, the limited number of potentially polymorphic sites generally do not correspond to fixed diagnostic nucleotide position characters separating taxa within this species complex. Previously unrecognized lineages inferred from ITS sequence data may represent undescribed species-level lineages or reflect uncharacterized aspects of nrDNA evolution.

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