Phylogenetic analyses of New Caledonian Metrosideros and Carpolepis (Myrtaceae) from nrDNA (ITS) sequences

2000 ◽  
Vol 13 (6) ◽  
pp. 919 ◽  
Author(s):  
Shane D. Wright ◽  
D. Jeannette Keeling ◽  
Fern G. Ashton ◽  
John W. Dawson ◽  
Richard C. Gardner

We have analysed the phylogenetic relationships of all known species in the genera Metrosideros and Carpolepis (Myrtaceae) from New Caledonia. Variation in nucleotide characters from the internally transcribed spacers of nuclear ribosomal DNA was used to construct parsimony and neighbour-joining phylogenies. These show that there is a large measure of congruence between the existing morphological taxonomy for those species and the relationships inferred from analyses of sequence variation. However, the DNA analyses suggest that Carpolepis may have only equal ranking to the infrageneric Metrosideros clades. The DNA analyses also nest M. tetrasticha among the species of subg. Metrosideros, as opposed to its present classification as a monotypic section (Neocaledonica) within subg. Mearnsia. On the basis of these findings, and of the observed differentiation shown in the analyses between the sectional clades Calyptropetala and Mearnsia of subg. Mearnsia, equivalent rankings may be appropriate for four infrageneric clades in Metrosideros. These four are currently classified as the genus Carpolepis (three species), and subg. Metrosideros (seven species), subg. Mearnsia sect. Mearnsia (five species) and subg. Mearnsia sect. Calyptropetala (five species) within Metrosideros.

PhytoKeys ◽  
2020 ◽  
Vol 140 ◽  
pp. 11-22
Author(s):  
Izai A. B. Sabino Kikuchi ◽  
Paul J. A. Keβler ◽  
André Schuiteman ◽  
Jin Murata ◽  
Tetsuo Ohi-Toma ◽  
...  

The orchid tribe Tropidieae comprises three genera, Tropidia, Corymborkis and Kalimantanorchis. There are three fully mycoheterotrophic species within Tropidieae: Tropidia saprophytica, T. connata and Kalimantanorchis nagamasui. A previous phylogenetic study of K. nagamasui, based only on plastid matK data, placed K. nagamasui outside the clade of Tropidia and Corymborkis without support. In this study, we performed phylogenetic analyses using a nuclear ribosomal DNA spacer (ITS1-5.8S-ITS2), a low-copy nuclear coding gene (Xdh) and a mitochondrial intron (nad1b-c intron) to study the phylogenetic relationships within Tropidieae. We included six photosynthetic and all three fully mycoheterotrophic Tropidieae species. The resulting phylogenetic trees placed these fully mycoheterotrophic species inside the Tropidia clade with high support. In our trees, these three species do not form a monophyletic group together, because the photosynthetic T. graminea is nested amongst them. Our results also suggest that the loss of photosynthetic ability occurred at least twice in Tropidia.


Phytotaxa ◽  
2019 ◽  
Vol 427 (3) ◽  
pp. 186-199
Author(s):  
ARCHANA SINGH ◽  
NIKHIL KUMAR SINGH ◽  
PARAS NATH SINGH ◽  
RAGHVENDRA SINGH ◽  
NAWAL KISHORE DUBEY

Ochroconis helicteris, a novel species of the oligotrophic genus Ochroconis (Sympoventuriaceae, Venturiales), has been described and illustrated. Morphologically, this species has characters similar to allied species in the genus Ochroconis, but differs in conidial dimensions and shape. Phylogenetic analyses using nuclear ribosomal DNA gene ITS and protein coding gene BT2 revealed it clustering as monophyletic clade which was separated from known Ochroconis species. New species was isolated from leaf surface of medicinal plant Helicteris isora L.


2012 ◽  
Vol 88 (1) ◽  
pp. 64-68 ◽  
Author(s):  
G.H. Liu ◽  
W. Zhou ◽  
A.J. Nisbet ◽  
M.J. Xu ◽  
D.H. Zhou ◽  
...  

AbstractTrichuris trichiura and Trichuris suis parasitize (at the adult stage) the caeca of humans and pigs, respectively, causing trichuriasis. Despite these parasites being of human and animal health significance, causing considerable socio-economic losses globally, little is known of the molecular characteristics of T. trichiura and T. suis from China. In the present study, the entire first and second internal transcribed spacer (ITS-1 and ITS-2) regions of nuclear ribosomal DNA (rDNA) of T. trichiura and T. suis from China were amplified by polymerase chain reaction (PCR), the representative amplicons were cloned and sequenced, and sequence variation in the ITS rDNA was examined. The ITS rDNA sequences for the T. trichiura and T. suis samples were 1222–1267 bp and 1339–1353 bp in length, respectively. Sequence analysis revealed that the ITS-1, 5.8S and ITS-2 rDNAs of both whipworms were 600–627 bp and 655–661 bp, 154 bp, and 468–486 bp and 530–538 bp in size, respectively. Sequence variation in ITS rDNA within and among T. trichiura and T. suis was examined. Excluding nucleotide variations in the simple sequence repeats, the intra-species sequence variation in the ITS-1 was 0.2–1.7% within T. trichiura, and 0–1.5% within T. suis. For ITS-2 rDNA, the intra-species sequence variation was 0–1.3% within T. trichiura and 0.2–1.7% within T. suis. The inter-species sequence differences between the two whipworms were 60.7–65.3% for ITS-1 and 59.3–61.5% for ITS-2. These results demonstrated that the ITS rDNA sequences provide additional genetic markers for the characterization and differentiation of the two whipworms. These data should be useful for studying the epidemiology and population genetics of T. trichiura and T. suis, as well as for the diagnosis of trichuriasis in humans and pigs.


Phytotaxa ◽  
2019 ◽  
Vol 392 (2) ◽  
pp. 127
Author(s):  
ERIK ZAJTA ◽  
TORDA VARGA ◽  
GÁBOR M KOVÁCS ◽  
BÁLINT DIMA

The ectomycorrhiza forming basidiomycete Hygrophorus penarius sensu lato was recognized as two species, H. penarioides and H. penarius in 2007 based on molecular and morphological evidence. However, this was based on few collections of restricted geographical origin and no studies have performed molecular analysis on additional specimens to date.To this end we sequenced the nrDNA ITS regions of 29 H. penarius s. l. collections from Hungary and Slovakia and analysed with collections from previous studies. Bayesian and Maximum Likelihood phylogenetic analyses confirmed the separation of H. penarioides and H. penarius in two clades with the majority of the specimens belonging to H. penarioides and only three to H. penarius. Despite the strong support of the lineages, there was no coherent difference in basidiome and spore traits. We also provide the first evidence of an intraspecific nrDNA sequence variation in the ITS2 region of H. penarioides together with morphological variability that has not been reported to date.On the basis of our result, we conclude that the Quercus associated H. penarioides is far more common in Hungary than the Fagus associated H. penarius and we suggest that identification of the two species in the absence of DNA sequence analysis should be handled with caution, especially when herbarium specimens are examined.


2019 ◽  
Vol 190 (4) ◽  
pp. 345-358 ◽  
Author(s):  
Yasaman Salmaki ◽  
Günther Heubl ◽  
Maximilian Weigend

AbstractStachydeae, comprising c. 470 species, are one of the most diverse and taxonomically puzzling groups in Lamioideae. In the present study, the phylogenetic relationships in the Eurystachys clade (a phylogenetic name for all genera attributed to Stachydeae except Melittis) were reconstructed utilizing nuclear ribosomal DNA sequences (nrETS, 5S-NTS) from 148 accessions in 12 genera. Our phylogenetic results recovered Stachys as paraphyletic with numerous traditionally recognized genera nested in it. A broadly defined Eurystachys clade, however, was monophyletic. Unlike previous studies, the present study was able to resolve the group into 12 well-supported clades, named here as (1) Eriostomum, (2) Stachys, (3) Prasium, (4) Setifolia, (5) Distantes, (6) Burgsdorfia, (7) Hesiodia, (8) Empedoclia, (9) Sideritis, (10) Marrubiastrum, (11) Swainsoniana and (12) Olisia. These 12 clades were formally named in a phylogenetic nomenclature for the Eurystachys clade. Several infrageneric units were retrieved as monophyletic, namely Sideritis sections Burgsdorfia, Empedoclia and Hesiodia, Sideritis subgenus Marrubiastrum and Stachys sections Eriostomum (including Stachys section Mucronata) and Setifolia. The findings of this study also provide the basis for a future formal classification, with two options: (1) splitting of the Eurystachys clade into 12 monophyletic genera, all of them based on pre-existing genus names and redefined to encompass additional taxa, but without clear morphological apomorphies; or (2) lumping of all segregates into a broadly defined Stachys, including widely recognized and well-defined segregates such as Prasium and Sideritis.


Sign in / Sign up

Export Citation Format

Share Document