Molecular phylogenetic studies in the genus Amanita

1998 ◽  
Vol 76 (7) ◽  
pp. 1170-1179 ◽  
Author(s):  
Michael Weiß ◽  
Zhu-Liang Yang ◽  
Franz Oberwinkler

A group of 49 Amanita species that had been thoroughly examined morphologically and anatomically was analyzed by DNA sequence comparison to estimate natural groups and phylogenetic relationships within the genus. Nuclear DNA sequences coding for a part of the ribosomal large subunit were determined and evaluated using neighbor-joining with bootstrap analysis, parsimony analysis, conditional clustering, and maximum likelihood methods. Sections Amanita, Caesarea, Vaginatae, Validae, Phalloideae, and Amidella were substantially confirmed as monophyletic groups, while the monophyly of section Lepidella remained unclear. Branching topologies between and within sections could also partially be derived. Subgenera Amanita and Lepidella were not supported. The Mappae group was included in section Validae. Grouping hypotheses obtained by DNA analyses are discussed in relation to the distribution of morphological and anatomical characters in the studied species.Key words: fungi, basidiomycetes phylogeny, Agaricales, Amanita systematics, large subunit rDNA, 28S.

2012 ◽  
Vol 279 (1737) ◽  
pp. 2396-2401 ◽  
Author(s):  
Rachunliu G. Kamei ◽  
Diego San Mauro ◽  
David J. Gower ◽  
Ines Van Bocxlaer ◽  
Emma Sherratt ◽  
...  

The limbless, primarily soil-dwelling and tropical caecilian amphibians (Gymnophiona) comprise the least known order of tetrapods. On the basis of unprecedented extensive fieldwork, we report the discovery of a previously overlooked, ancient lineage and radiation of caecilians from threatened habitats in the underexplored states of northeast India. Molecular phylogenetic analyses of mitogenomic and nuclear DNA sequences, and comparative cranial anatomy indicate an unexpected sister-group relationship with the exclusively African family Herpelidae. Relaxed molecular clock analyses indicate that these lineages diverged in the Early Cretaceous, about 140 Ma. The discovery adds a major branch to the amphibian tree of life and sheds light on both the evolution and biogeography of caecilians and the biotic history of northeast India—an area generally interpreted as a gateway between biodiversity hotspots rather than a distinct biogeographic unit with its own ancient endemics. Because of its distinctive morphology, inferred age and phylogenetic relationships, we recognize the newly discovered caecilian radiation as a new family of modern amphibians.


2000 ◽  
Vol 77 (12) ◽  
pp. 1790-1800 ◽  
Author(s):  
Alexandra Riethmüller ◽  
Michael Weiß ◽  
Franz Oberwinkler

To reveal phylogenetic relationships within the Peronosporomycetes (Oomycetes), we sequenced a part of the nuclear rDNA coding for the ribosomal large subunit of 46 Peronosporomycetes species and one representative of the Xanthophyta. The main emphasis of our study was put on the phylogenetic relationships within the Saprolegniomycetidae. We supplemented our data with a sequence of Phytophthora megasperma Drechsler from GenBank. Two sets of sequences were analysed using the neighbor-joining method, statistically supported by the bootstrap method, as well as the maximum parsimony method. Our results are well compatible with the tripartite subclassification of the Peronosporomycetes into Saprolegniomycetidae, Rhipidiomycetidae and Peronosporomycetidae, as well as with the placement of the orders Saprolegniales and Leptomitales in the Saprolegniomycetidae. Pachymetra chaunorhiza Croft & Dick, which has been placed in the Sclerosporales, was grouped within the Saprolegniales. Within the Peronosporomycetidae, the orders Peronosporales and Pythiales could not be separated. There are indications that Phytophthora de Bary and the Peronosporales form a common natural group. The genus Achlya Nees proved to be a heterogeneous group.


1993 ◽  
Vol 71 (9) ◽  
pp. 1249-1265 ◽  
Author(s):  
G. Hausner ◽  
J. Reid ◽  
G. R. Klassen

Phylogenetic analysis of partial rDNA sequences suggests that Ophiostoma should remain the sole genus of the Ophiostomataceae, and this should be the sole family within the Ophiostomatales, whereas Ceratocystis s.s. would be best disposed within the Microascales. Although morphological criteria suggest that the genus Ophiostoma is heterogeneous, analysis of partial small subunit rDNA sequence data shows that Ophiostoma (excluding O. roraimense) represents a monophyletic taxon. Analysis of a partial large subunit rDNA data set, which included sequences from 55 species assignable to Ophiostoma, failed to support the strict subdivision of the genus based on either ascospore characters or the nature of the anamorph. Key words: Ceratocystis, Microascus, Ophiostoma, partial rDNA sequences, phylogeny.


2012 ◽  
Vol 87 (2) ◽  
pp. 160-173 ◽  
Author(s):  
A. Chaudhary ◽  
H.S. Singh

AbstractThe present paper describes the taxonomy of two new monogeneans, namely, Thaparocleidus longiphallus sp. n. and T. siloniansis sp. n., based on morphological, morphometric and molecular biological analysis, collected from the fish Wallago attu (Bloch & Schn.) and Silonia silondia (Ham.), respectively, at Meerut, UP, India. Genetic characterization of the two new species is based on sequence analyses of the rDNA 28S gene using neighbour-joining and maximum-parsimony techniques. These methods are congruent in depicting T. longiphallus sp. n. and T. siloniansis sp. n. as closely related species, but distinct from each other and forming a subclade with other species of the genus Thaparocleidus Jain, 1952. Secondary-structure models of the large subunit rDNA of the two species were also predicted using a combined comparative and thermodynamic approach. Molecular morphometric and phylogenetic relationships of the isolates of the Thaparocleidus species are discussed in detail.


The Auk ◽  
2002 ◽  
Vol 119 (3) ◽  
pp. 695-714 ◽  
Author(s):  
I. J. Lovette ◽  
E. Bermingham

AbstractThe wood-warblers (family Parulidae) fall within a radiation of passerine birds commonly known as the New World nine-primaried oscines. Defining familial relationships within that radiation has previously been challenging because of its extremely high diversity, a paucity of phylogenetically informative morphological characters, and an apparent high rate of cladogenesis early in the radiation's history. Here, analyses of mitochondrial and nuclear DNA sequences demonstrate that the 25 extant genera traditionally placed in the Parulidae do not form a monophyletic group. Instead, all reconstructions identify a well-resolved clade of 19 genera (Vermivora, Parula, Dendroica, Catharopeza, Mniotilta, Setophaga, Protonotaria, Helmitheros, Limnothlypis, Seiurus, Oporornis, Geothlypis, Wilsonia, Cardellina, Ergaticus, Myioborus, Euthlypis, Basileuterus, and Phaeothlypis) that are all morphologically typical wood-warblers traditionally placed in the Parulidae. Six genera traditionally assigned to the Parulidae—Microligea, Teretistris, Zeledonia, Icteria, Granatellus, and Xenoligea—fall outside this highly supported clade in all mtDNA-based and nuclear DNA-based reconstructions, and each is probably more closely allied to taxa traditionally placed in other nine-primaried oscine families. The long, well-supported, and independently confirmed internode at the base of this wood-warbler clade provides the opportunity to define a monophyletic Parulidae using several complementary molecular phylogenetic criteria. Support for those relationships comes from reconstructions based on a range of nucleotide-intensive (from 894 to 3,638 nucleotides per taxon) and taxon-intensive (45 to 128 species) analyses of mtDNA sequences, as well as independent reconstructions based on nucleotide substitutions in the nuclear-encoded c-mos gene. Furthermore, the 19 typical wood-warbler genera share a synapomorphic one-codon c-mos deletion not found in other passerines. At a slightly deeper phylogenetic level, our mtDNA-based reconstructions are consistent with previous morphologic and genetic studies in suggesting that many nine-primaried oscine taxa have unanticipated affinities, that many lineages arose during an early and explosive period of cladogenesis, and that the generation of a robust nine-primaried oscine phylogeny will require robust taxonomic sampling and extensive phylogenetic information.


Zootaxa ◽  
2007 ◽  
Vol 1668 (1) ◽  
pp. 413-425 ◽  
Author(s):  
P. J. GULLAN ◽  
L. G. COOK

The superfamily Coccoidea contains nearly 8000 species of plant-feeding hemipterans comprising up to 32 families divided traditionally into two informal groups, the archaeococcoids and the neococcoids. The neococcoids form a monophyletic group supported by both morphological and genetic data. In contrast, the monophyly of the archaeococcoids is uncertain and the higher level ranks within it have been controversial, particularly since the late Professor Jan Koteja introduced his multi-family classification for scale insects in 1974. Recent phylogenetic studies using molecular and morphological data support the recognition of up to 15 extant families of archaeococcoids, including 11 families for the former Margarodidae sensu lato, vindicating Koteja’s views. Archaeococcoids are represented better in the fossil record than neococcoids, and have an adequate record through the Tertiary and Cretaceous but almost no putative coccoid fossils are known from earlier. In contrast, the sister group of the scale insects (Aphidoidea) has a more informative Jurassic and Triassic record. Relationships among most scale insect families are unresolved in phylogenetic trees based on nuclear DNA sequences, and most nodes in trees based on morphological data, including those from adult males, are poorly supported. Within the neococcoids, the Eriococcidae is not monophyletic and the monophyly of the Coccidae and Diaspididae may be compromised by the current family-level recognition of a few species-poor autapomorphic groups.


2020 ◽  
Vol 44 (1) ◽  
pp. 206-239 ◽  
Author(s):  
Y.-F. Sun ◽  
D.H. Costa-Rezende ◽  
J.-H. Xing ◽  
J.-L. Zhou ◽  
B. Zhang ◽  
...  

Amauroderma s.lat. has been defined mainly by the morphological features of non-truncate and double-walled basidiospores with a distinctly ornamented endospore wall. In this work, taxonomic and phylogenetic studies on species of Amauroderma s.lat. are carried out by morphological examination together with ultrastructural observations, and molecular phylogenetic analyses of multiple loci including the internal transcribed spacer regions (ITS), the large subunit of nuclear ribosomal RNA gene (nLSU), the largest subunit of RNA polymerase II (RPB1) and the second largest subunit of RNA polymerase II (RPB2), the translation elongation factor 1-α gene (TEF) and the β-tubulin gene (TUB). The results demonstrate that species of Ganodermataceae formed ten clades. Species previously placed in Amauroderma s.lat. are divided into four clades: Amauroderma s.str., Foraminispora, Furtadoa and a new genus Sanguinoderma. The classification of Amauroderma s. lat. is thus revised, six new species are described and illustrated, and eight new combinations are proposed. SEM micrographs of basidiospores of Foraminispora and Sanguinoderma are provided, and the importance of SEM in delimitation of taxa in this study is briefly discussed. Keys to species of Amauroderma s.str., Foraminispora, Furtadoa, and Sanguinoderma are also provided.


2012 ◽  
Vol 58 (6) ◽  
pp. 837-850 ◽  
Author(s):  
Lanping Zheng ◽  
Junxing Yang ◽  
Xiaoyong Chen

Abstract The Labeoninae is a subfamily of the family Cyprinidae, Order Cypriniformes. Oromandibular morphology within the Labeoninae is the greatest among cyprinid fishes. Although several phylogenetic studies about labeonines have been undertaken the results have been inconsistent and a comprehensive phylogeny is needed. Further, an incongruence between morphological and molecular phylogeny requires a systematic exploration of the significance of morphological characters on the basis of the molecular phylogeny. In this study, a total of 292 nucleotide sequences from 73 individuals (representing 24 genera and 73 species) of Labeoninae were analyzed. The results of the phylogenetic analysis indicate that there are four major clades within Labeoninae and three monophyletic lineages within the fourth clade. Results of the character evolution show that all oroman-dibular morphological characters are homoplastically distributed on the molecular phylogenetic tree and suggests that these characters evolved several times during the history of labeonines. In particular, the labeonine , a specific disc on the lower lip, has been acquired three times and reversed twice. These morphological characters do not have systematic significance but can be useful for taxonomy. The results of biogeography suggest that the Labeoninae originated from Southeast Asia and separately dispersed to Africa, East Asia and South Asia.


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