Phylogenetic relationships of 10 grass species: an assessment of phylogenetic utility of the internal transcribed spacer region in nuclear ribosomal DNA in monocots

Genome ◽  
1994 ◽  
Vol 37 (1) ◽  
pp. 112-120 ◽  
Author(s):  
C. Hsiao ◽  
N. J. Chatterton ◽  
K. H. Asay ◽  
K. B. Jensen

Entire sequences of the internal transcribed spacers (ITSs) and 5.8S subunit of nuclear ribosomal DNA (nrDNA) were obtained from nine grass species by direct double-stranded sequencing of polymerase chain reaction (PCR) amplified DNA fragments. These sequences from subfamily Pooideae (Triticum aestivum, Crithodium monococcum, Sitopsis speltoides, Hordeum vulgare, Secale montanum, Avena longiglumis, Bromus inermis, Brachypodium distachyon) and subfamily Panicoideae (Sorghum bicolor) together with published ITS sequence of rice (Oryza sativa, Bambusoideae) were analyzed using Wagner parsimony (PAUP) and the neighbor-joining distance method to assess the phylogenetic utility of ITS sequences at various taxonomic levels. Among the aligned sequences that ranged from 588 to 603 nucleotides in length, 118 of 269 variable sites contained potential phylogenetic information. A member of Bromus, B. inermis, was the sister taxon to the Triticeae species. Brachypodium was more distantly related to Triticeae than was Bromus or Avena. These data, with Oryza sativa as the outgroup, indicate monophyly of the Pooideae species and of the members of the tribe Triticeae within Pooideae. Phylogenetic trees of the 10 grass species generated from the ITS sequence data were in general agreement with phylogenies based on molecular data from ribosomal RNA (rRNA) and chloroplast DNA (cpDNA) of similar grass taxa. This study reaffirms that sequences of the ITS region are useful for phylogenetic inference among closely related monocot species.Key words: Poaceae, Pooideae, Triticeae, DNA sequences, molecular phylogeny.

2020 ◽  
Vol 48 (3) ◽  
pp. 1332-1340
Author(s):  
Ilhan KAYA ◽  
Ibrahim DEMIR ◽  
Mustafa USTA ◽  
Hikmet M. SIPAHIOĞLU

Nuclear ribosomal DNA (nrDNA) sequence data of the Cuscuta genus, which have been considered as one of the most popular sequences for phylogenetic inference in plants, have been studied from a phylogenetic perspective in agricultural and non-agricultural lands of Turkey. The samples of Cuscuta spp. were collected from different geographical regions of Turkey between the years of 2013-2015. Some other species, not available locally, were taken from the herbarium samples of some research units. In order to study the phylogenetic relations of collected species, DNA isolations were made from body tissue samples. Conserved regions on ribosomal DNA (rDNA) were amplified by universal primers via PCR method and cloned into a proper cloning vector. The cloned DNA fragments were sequenced and analysed by web-based and computer programs. DNA sequences of certain species were recorded to the National Center for Biotechnology Information (NCBI) database. Based on the morphological examination and molecular analyses of fresh and the herbarium specimen, 8 species were identified. The identified species were C. hyalina (Gene bank accession no. KY020420), C. monogyna (KY020421), C. europaea (KY020422), C. palaestina (KY020423), C. approximata (KY020424), C. kurdica (KY020427), C. kotschyana (KY020430) and C. babylonica (KY020431). The ITS (Internal Transcribed Spacer) region contains several indels in identified Cuscuta species with the length varying from 668 to 730 bp. Sequence divergence ranges from 1.00% to 8.00% within Cuscuta spp. Based on our findings, the ITS sequences provided phylogenetically informative results in combination with the secondary structures.


2000 ◽  
Vol 57 (2) ◽  
pp. 261-270 ◽  
Author(s):  
T. H. WOOD ◽  
W. M. WHITTEN ◽  
N. H. WILLIAMS

The phylogeny of Hedychium J. Koenig was estimated using sequence data of internal transcribed spacer regions 1 and 2 (ITS1, ITS2) and 5.8S nuclear ribosomal DNA. Sequences were determined for 29 taxa, one interspecific hybrid of Hedychium and one species in each of 16 other genera of Zingiberaceae representing tribes Hedychieae, Globbeae, Zingibereae and Alpinieae. Cladistic analysis of these data strongly supports the monophyly of Hedychium, but relationships to other genera are poorly supported. Within Hedychium, four major clades are moderately supported. These clades are also distinguishable on the basis of number of flowers per bract and distribution. Stahlianthus, Curcuma, and Hitchenia also form a strongly supported clade. Based on this limited sample, the currently defined tribes of Zingiberoideae are not monophyletic. The Asiatic genera form a monophyletic group within this broadly defined Hedychieae. The taxonomy and biogeography of Hedychium are reviewed.


2018 ◽  
Vol 25 (2) ◽  
pp. 209-214
Author(s):  
M. Ajmal Ali

The nuclear ribosomal DNA (nrDNA) internal transcribed spacers (ITS) sequences is extensively used in the plant molecular phylogenetics for plant taxonomic identification and DNA barcoding purposes because the nrDNA ITS gene is easy to amplify by using the universal primers, its length is shorter and thus easy to sequence, and has strong discrimination power to distinguish the taxon at the species level. The present molecular phylogenetic analysis of ITS nrDNA sequences focuses to determine the taxonomic status of an unresolved endemic taxon Kickxia abhaica D.A. Sutton (Family Plantaginaceae, tribe Antirrhineae) reported from Saudi Arabia. The analysis supports the transfer of K. abhaica under the genus Nanorrhinum.


2005 ◽  
Vol 79 (3) ◽  
pp. 257-267 ◽  
Author(s):  
M.D. Bargues ◽  
S. Mas-Coma

AbstractSnails of the family Lymnaeidae are of great parasitological importance due to the numerous helminth species they transmit, mainly trematodiases (such as fascioliasis) of considerable medical and veterinary impact. The present knowledge of the genetics and host–parasite relationships of this gastropod group is far from adequate. Fascioliasis is caused by two species, Fasciola hepatica and F. gigantica, which, as in the case of other trematodes, show a marked snail host specificity. Many lymnaeid species involved in fascioliasis transmission still show a confused systematic-taxonomic status. The need for tools to distinguish and characterize species and populations of lymnaeids is evident and the present review concerns new molecular tools developed in recent years using nuclear ribosomal DNA sequences. The small subunit or 18S gene and the internal transcribed spacers ITS-2 and ITS-1 are analysed and evaluated as markers for taxon differentiation and relationships within the Lymnaeidae from genus and species levels to subspecies and population levels. rDNA sequence differences and genetic distances, and their value for reconstructing phylogenetic trees using different methods are considered. Nuclear rDNA sequences are appropriate tools on which to base a review of the systematics and taxonomy of the family Lymnaeidae, without excluding other valuable snail characteristics already available. A reconstruction of the lymnaeid system towards a more natural classification will undoubtedly be helpful in understanding parasite transmission and epidemiological features as well the dispersion of an emerging-reemerging disease such as fascioliasis. Nomenclature for nuclear rDNA genotyping in lymnaeids includes the main rDNA sequence regions able to furnish important information on interspecific differentiation and grouping as well as intraspecific variability of lymnaeid species. The composite haplotype code includes the rDNA markers arranged in order according to their well-known usefulness, in its turn related to their respective, more or less rapid evolutionary ratios, to distinguish between different taxonomic levels, from supraspecific taxa to the species level and up to the population level.


2003 ◽  
Vol 16 (1) ◽  
pp. 19 ◽  
Author(s):  
Daniel J. Murphy ◽  
Joseph T. Miller ◽  
Randall J. Bayer ◽  
Pauline Y. Ladiges

The largest monophyletic group within Acacia is subgenus Phyllodineae, with more than 950 predominately Australian species, the majority characterised by adult foliage consisting of phyllodes. Molecular sequence data from the internal transcribed spacers (ITS) of the nuclear ribosomal DNA repeat were used to investigate the monophyly of seven sections within the subgenus. A nested PCR approach was used to amplify the ITS region. Fifty-one species representative of all sections were sequenced together with one outgroup taxon Lysiloma divaricata (Ingeae).Phylogenetic parsimony analysis suggested that there are two main clades within Phyllodineae but that only one section, Lycopodiifoliae, is apparently monophyletic. In one of the main clades, Lycopodifoliae is related to some taxa in sections Alatae and Pulchellae and some members of section Phyllodineae. In the second main clade, sections Juliflorae, Plurinerves and Botrycephalae cluster with other members of section Phyllodineae. The two sections that are characterised by bipinnate foliage, Botrycephalae and Pulchellae, are nested within phyllodinous clades, indicating that at least two separate reversals to bipinnate leaves have occurred. Botrycephalae is paraphyletic with respect to taxa from section Phyllodineae that have single-nerved phyllodes and racemose inflorescences.


HortScience ◽  
2002 ◽  
Vol 37 (3) ◽  
pp. 595-598 ◽  
Author(s):  
Jianhua Li ◽  
Michael S. Dosmann ◽  
Peter Del Tredici ◽  
Susyn Andrews

Sequences of the internal transcribed spacers (ITS) of nuclear ribosomal DNA were used to examine genetic divergence of the two species of katsura [Cercidiphyllum japonicum Sieb. & Zucc. and Cercidiphyllum magnificum (Nakai) Nakai] and four clones of weeping katsura (`Amazing Grace', `Tidal Wave', `Pendulum', and `Morioka Weeping'), and to characterize the affinity of these weeping katsura to both species. Our results indicate that C. japonicum and C. magnificum are genetically distinct, supporting the recognition of them as separate species. Based on our DNA sequence data and morphological evidence, all weeping selections are phylogenetically derived from C. japonicum, not C. magnificum; nor are they of a hybrid origin between C. japonicum and C. magnificum. We propose the new cultivar-group Cercidiphyllum japonicum Weeping Group to include all katsura clones of weeping or pendulous habit, and recognize the cultivar epithet `Morioka Weeping' and its application to the excurrent and upright clone obtained from Japan and distributed in North America by the Arnold Arboretum.


2000 ◽  
Vol 86 (3) ◽  
pp. 588 ◽  
Author(s):  
Steven A. Nadler ◽  
Eric P. Hoberg ◽  
Deborah S. S. Hudspeth ◽  
Lora G. Rickard

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