Search results for "Systematics"
showing 10 items of 6702 documents
Morphologically similar but not closely related: the long-spored species of Subulicystidium (Trechisporales, Basidiomycota)
2020
AbstractSpecies boundaries and geographic distribution of corticioid fungi (resupinate Basidiomycota) are often poorly known. Our recent study on Subulicystidium showed that species diversity in this genus is at least twice as high as previously recognized. This re-estimation of the species diversity was based on a study of only a part of the genus. The present study sheds light on molecular and morphological diversity of three more species. We generated 27 ITS and 24 28S nuclear ribosomal DNA sequences from 49 specimens labelled as Subulicystidium cochleum, S. longisporum and S. perlongisporum and collected in distant geographic localities. We assessed pairwise dissimilarities and phylogen…
Molecular Evolution and the Phylogenetic Relationships of the African Toad, Bufo danielae PERRET, 1977 (Salientia : Bufonidae)
1980
Abstract Phylogenetic relationships of the African toad Bufo danielae are investigated using a variety of biochemical approaches. Nuclear DNA content was assayed and compared to representatives of three species groups of African Bufo. Cellogel electrophoresis of plasma proteins was performed and patterns of B. danielae compared with those of representatives of the African B. regularis species complex. Finally microcomplement fixation analyses of albumin relationships of B. danielae and African Bufo were carried out. The strengths of the varied approaches for phylogenetic analysis are discussed. B. danielae appears most closely related to B. maculatus and B. pusillus, it being some 5-6 mill…
Salicornia L. (Amaranthaceae) in South Africa and Namibia: rapid spread and ecological diversification of cryptic species
2013
In Salicornia, morphology does not provide reliable diagnostic characters supporting the true extent of evolutionary divergence in the genus, and species concepts have been challenged by molecular analyses. Here, we report the results of an analysis of 91 accessions of the S. meyeriana complex from South Africa and Namibia using the measurements of 38 morphological traits and external transcribed spacer (ETS) sequence data. Morphological data were analysed using discriminant analysis, principal coordinate analysis and nonmetric multidimensional scaling. Phylogenetic divergence was compared with the geographical and ecological diversity of the sampled populations. Tree topology corresponds t…
Phaenoglyphis villosa(Hartig 1841) (Hymenoptera: Figitidae: Charipinae): a complex of species or a single but very variable species?
2007
The status of Phaenoglyphis villosa (Hartig 1841), the only species in this genus with the radial cell partially open along the wing margin, is discussed. A complete synonymy list, redescription, morphological variability and some biological peculiarities of P. villosa are given. After studying numerous specimens from different countries from all continents, we concluded that this species is either very variable or might be a complex of sibling species. Auloxysta tarsata Belizin 1973, is a new synonym of P. villosa and P. dolichocera (Cameron 1889) was re-established as a valid species. Resume. Phaenoglyphis villosa (Hartig 1841) (Hymenoptera : Figitidae : Charipinae) : un complexe d'espece…
Deterioration patterns in diapausing egg banks of Brachionus (Müller, 1786) rotifer species
2005
Rotifers are cyclical parthenogens that produce sexual diapausing eggs at some stage in their life cycle. These eggs are encysted embryos that remain viable for extended periods in lake and pond sediments, thus acting as an egg bank with many ecological and evolutionary consequences. Despite its importance to rotifer evolution, there are no studies on resting egg deterioration and associated processes in natural environments. In this study, more than 4000 diapausing eggs of species from the Brachionus plicatilis complex, which includes several closely related cryptic species, were collected from different sediment depths in 15 ponds in eastern Spain and were classified according to three fe…
Gisekia(Gisekiaceae): Phylogenetic relationships, biogeography, and ecophysiology of a poorly known C4lineage in the Caryophyllales
2014
• Premise of the study: Gisekiaceae are a monogeneric family of the core Caryophyllales distributed in arid regions of Africa and Asia. The only widespread species of the genus, Gisekia pharnaceoides, performs C4 photosynthesis based on CO2 compensation point measurements. This study investigates the C4 syndrome and its evolution in Gisekia. The infrageneric relationships, distribution and bioclimatic preferences of Gisekia are also investigated.• Methods: Leaf gas exchange characteristics, activity of Rubisco and major C4 cycle enzymes, and ultrastructural characteristics of mesophyll and bundle sheath cells are studied for Gisekia pharnaceoides. δ13C values and leaf anatomy are analyzed f…
Convergent evolution of aposematic coloration in Neotropical poison frogs: a molecular phylogenetic perspective
2003
Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2014-02-26T17:17:10Z No. of bitstreams: 1 WOS000186417800006.pdf: 196897 bytes, checksum: cbe901a47807d22aec173ee8cc011a64 (MD5) Made available in DSpace on 2014-02-26T17:17:10Z (GMT). No. of bitstreams: 1 WOS000186417800006.pdf: 196897 bytes, checksum: cbe901a47807d22aec173ee8cc011a64 (MD5) Previous issue date: 2003-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:59:12Z No. of bitstreams: 1 WOS000186417800006.pdf: 196897 bytes, checksum: cbe901a47807d22aec173ee8cc011a64 (MD5) Made available in DSpace on 2014-05-20T13:59:12Z (GMT). No. of bitstreams: 1 WOS000186417800006.pdf: 196…
A mitochondrial phylogeography of Brachidontes variabilis (Bivalvia: Mytilidae) reveals three cryptic species
2007
This study examined genetic variation across the range of Brachidontes variabilis to produce a molecular phylogeography. Neighbour joining (NJ), minimum evolution (ME) and maximum parsimony (MP) trees based on partial mitochondrial DNA sequences of 16S-rDNA and cytochrome oxidase (COI) genes revealed three monophyletic clades: (1) Brachidontes pharaonis s.l. from the Mediterranean Sea and the Red Sea; (2) B. variabilis from the Indian Ocean; (3) B. variabilis from the western Pacific Ocean. Although the three clades have never been differentiated by malacologists employing conventional morphological keys, they should be ascribed to the taxonomic rank of species. The nucleotide divergences b…
New insights into the taxonomy and phylogeny of social voles inferred from mitochondrial cytochrome b sequences
2012
We sequenced the entire cytochrome b gene in Microtus paradoxus from Turkmenistan and Microtus socialis from Crimea and Kalmykia. Phylogenetic relationships among social voles were reconstructed by the inclusion into analyses of a further 23 published haplotypes belonging to six species. The two probabilistic methods which were used in phylogenetic analyses, the Bayesian inference and Maximum Likelihood, yielded very similar results. Both trees showed two highly divergent lineages which were further subdivided into seven species. The socialis lineage encompassed four species (M. socialis, M. irani, M. anatolicus, and M. paradoxus), and the remaining three species clustered into the guenther…
Verrucoccum (Dothideomycetes, Dictyosporiaceae), a new genus of lichenicolous fungi on Lobaria s. lat. for the Dothidea hymeniicola species complex
2021
Two lichenicolous fungi, one growing on the thallus of Lobaria pulmonaria in the United Kingdom (Scotland) and the other in apothecia of Lobaria linita and L. oregana in northwestern North America (Alaska and British Columbia) and northeast Asia (Russian Far East, Khabarovsk Krai), show similarities to the species originally described as Dothidea hymeniicola (later transferred to Polycoccum s. lat and Endococcus) from a Lobaria s. lat. species in Central America. Critical morphological comparison showed that, despite the superficial resemblance between Alaskan, Canadian, Russian, and Scottish collections and the holotype of Dothidea hymeniicola, they can be distinguished by detailed microsc…