scholarly journals Systematic Relationship of Weeping Katsura Based on Nuclear Ribosomal DNA Sequences

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.

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.


1994 ◽  
Vol 51 (S1) ◽  
pp. 198-204 ◽  
Author(s):  
Ruth B. Phillips ◽  
Susan A. Manley ◽  
Thomas J. Daniels

DNA sequences of the second internal transcribed spacer (ITS2) of the nuclear ribosomal DNA were determined for six species of the genus Salvelinus: S. alpinus (Arctic char), S. malma (Dolly Varden), S. confluentus (bull trout), S. leucomaenis (Japanese char), S. fontinalis (brook trout), and S. namaycush (lake trout), and for Hucho perryi (huchen). The ITS2 sequence data (approximately 375 base pairs (bp)) were combined with previously determined sequence data for the ITS1 (approximately 575 bp), giving a total of 981 bp of aligned sequence for each species. Phylogenetic analysis of the aligned sequences was done using maximum parsimony, maximum likelihood, and distance matrix methods with H. perryi as an outgroup. The results were consistent with previous work based on comparisons of morphologies, allozymes, and karyotypes. Comparison of these results with those based on mitochondrial DNA sequences suggests that hybridization may have occurred between S. confluentus and S. alpinus or S. malma.


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.


2002 ◽  
Vol 80 (9) ◽  
pp. 1002-1017 ◽  
Author(s):  
Suzanne I Warwick ◽  
Ihsan A Al-Shehbaz ◽  
Robert A Price ◽  
Connie Sauder

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.


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.


1999 ◽  
Vol 37 (12) ◽  
pp. 3957-3964 ◽  
Author(s):  
Kerstin Voigt ◽  
Elizabeth Cigelnik ◽  
Kerry O'donnell

A molecular database for all clinically important Zygomycetes was constructed from nucleotide sequences from the nuclear small-subunit (18S) ribosomal DNA and domains D1 and D2 of the nuclear large-subunit (28S) ribosomal DNA. Parsimony analysis of the aligned 18S and 28S DNA sequences was used to investigate phylogenetic relationships among 42 isolates representing species of Zygomycetes reported to cause infections in humans and other animals, together with commonly cultured contaminants, with emphasis on members of the Mucorales. The molecular phylogeny provided strong support for the monophyly of the Mucorales, exclusive of Echinosporangium transversale andMortierella spp., which are currently misclassified within the Mucorales. Micromucor ramannianus, traditionally classified within Mortierella, and Syncephalastrum racemosum represent the basal divergences within the Mucorales. Based on the 18S gene tree topology, Absidia corymbiferaand Rhizomucor variabilis appear to be misplaced taxonomically. A. corymbifera is strongly supported as a sister group of the Rhizomucor miehei-Rhizomucor pusillusclade, while R. variabilis is nested withinMucor. The aligned 28S sequences were used to design 13 taxon-specific PCR primer pairs for those taxa most commonly implicated in infections. All of the primers specifically amplified DNA of the size predicted based on the DNA sequence data from the target taxa; however, they did not cross-react with phylogenetically related species. These primers have the potential to be used in a PCR assay for the rapid and accurate identification of the etiological agents of mucormycoses and entomophthoromycoses.


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.


2018 ◽  
Vol 93 (04) ◽  
pp. 486-493 ◽  
Author(s):  
N.B. Chilton ◽  
F. Huby-Chilton ◽  
A. Koehler ◽  
R.B. Gasser ◽  
I. Beveridge

AbstractThe phylogenetic relationships of 42 species of cloacinine nematodes belonging to three tribes (Coronostrongylinea, Macropostrongylinea and Zoniolaiminea) were examined based on sequence data of the first and second internal transcribed spacers (ITS-1 and ITS-2) of the nuclear ribosomal DNA. All nematodes examined are parasites of Australian macropodid marsupials. None of the three nematode tribes was monophyletic. Paraphyly was also encountered in three genera: Papillostrongylus, Monilonema and Wallabinema. Species within the genus Thallostonema were limited to a single host genus (i.e. Thylogale), whereas species within the five principal genera (Coronostrongylus, Macropostrongylus, Popovastrongylus, Wallabinema and Zoniolaimus) were found to occur in multiple host genera. Potential modes of evolution among these nematodes are discussed.


1997 ◽  
Vol 75 (4) ◽  
pp. 519-532 ◽  
Author(s):  
Y. J. Liu ◽  
S. O. Rogers ◽  
Y. J. Liu ◽  
J. F. Ammirati

The genus Cortinarius Fr. (Cortinariaceae, Agaricales) is divided into four or more subgenera. Dermocybe (Fr.) Sacc. has been recognized as either a subgenus of Cortinarius or a separate genus, distinguished in part by the presence of various anthraquinonic pigments. Nucleotide sequences of ribosomal DNA 5.8S and internal transcribed spacers were used to investigate the phylogenetic relationships among species of Dermocybe and selected taxa from subgenera of Cortinarius. Sequence data from 47 herbarium specimens representing 31 taxa (28 species plus 3 varieties) of Dermocybe and Cortinarius were analyzed using parsimony, maximum likelihood, and neighbor joining. In general, molecular data support the morphological groupings of the taxa, although they more closely correspond to biochemical (anthraquinone and other) analyses. Phylogenetic trees showed that, while the sections Dermocybe and Malicoriae are monophyletic, and the concolorous or almost concolorous red species (section Sanguineae, such as D. sanguinea and relatives) together formed a coherent clade, the subgenus Dermocybe sensu lato itself is polyphyletic. Cortinarius californicus clusters with taxa in Cortinarius, subgenus Telamonia, section Armillati. Dermocybe olivaceopicta is more closely related to other subgenera of Cortinarius than to Dermocybe. Within the genus Cortinarius, certain of the subgenera may actually represent coherent genera. Of the subgenera examined, Telamonia, Phlegmacium, and possibly Sericeocybe appear to represent well defined taxonomic groupings. However, current assignments of taxa within Leprocybe and Myxacium were inconsistent with the molecular data. Reorganization of some taxa and taxonomic groups is suggested. Key words: Dermocybe, Cortinarius, molecular phylogeny, rDNA, ITS1, ITS2.


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