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1.
The phylogenetic relationships of two cavefish, Phreatichthys andruzzii and Garra barreimiae, belonging to the family Cyprinidae, were investigated by sequencing the mitochondrial cytochrome b gene. These cavefish species are native to Somalia (eastern Africa) and Oman (southeastern Arabian peninsula), respectively, and so far no molecular support to their taxonomy and phylogenetic position was ever provided. The analysis of cytochrome b sequences showed that the species are monophyletic taxa, closely related to each other and to other species of the genus Garra. Molecular clock calculations allowed to date the origin of these hypogaean species back to the Plio-Pleistocene and support the hypothesis that African cyprinids originated from Miocenic immigrations of Asian ancestors.  相似文献   

2.
Nodulosphaeria is a ubiquitous genus that comprises saprobic, endophytic and pathogenic species associated with a wide variety of substrates and has 64 species epithets listed in Index Fungorum. The classification of species in the genus has been a major challenge due to a lack of understanding of the importance of characters used to distinguish taxa, as well as the lack of reference strains. The present study clarifies the phylogenetic placement of the genus and related species, using fresh collections from Italy. Four Nodulosphaeria species are characterized based on multi-loci analyses of ITS, LSU, SSU, TEF and RPB2 sequence datasets. Phylogenetic analyses indicate that Nodulosphaeria species group within the family Phaeosphaeriaceae as a distinct genus. The sexual morphs of Nodulosphaeria hirta and N. spectabilis are described and illustrated using modern concepts. Two new Nodulosphaeria species are introduced. The phylogenetic relationships and taxonomy of the genus Nodulosphaeria are discussed, but further sampling with fresh collections, reference or ex-type strains and molecular data are needed to obtain a better and natural classification for the genus.  相似文献   

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Recent collections and the type specimen of Marasmiellus juniperinus, the type species of the genus, were examined. Phylogenetic placement, based on ribosomal large subunit (LSU) and internally transcribed spacer (ITS) sequences, is within the lentinuloid clade, nested among Gymnopus taxa. This placement dictates genus name usage and phylogenetic position of other putative species of Marasmiellus. The mating system is tetrapolar.  相似文献   

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Nymphs and larvae belonging to Ixodes spp. were collected from a red fox in Turkey. The ticks were identified morphologically and molecularly (16S rDNA PCR and phylogenetic analysis) as I. kaiseri. Sequence and phylogenetic analyses show that our I. kaiseri isolate is very similar to I. kaiseri isolates collected from Germany, Serbia, Romania, and Hungary. Therefore, the existence of I. kaiseri has been demonstrated for the first time in Turkey. More studies relating to the regional distribution and vectorial competence of I. kaiseri are needed.  相似文献   

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This study was conducted to investigate the applicability of rpoB, which encodes the β subunit of RNA polymerase, to be used as an alternative to 16S rRNA gene sequence similarity analysis in the thermophilic genus Anoxybacillus. Partial rpoB sequences were generated for the 14 type strains of Anoxybacillus species and 6 other strains of four Anoxybacillus species. The sequences and the phylogenetic tree of rpoB were compared with those obtained from 16S rRNA gene analysis. The rpoB gene was found to provide a better resolution for Anoxybacillus species, with lower interspecies sequence similarities. The rpoB sequence similarity analysis permitted a more accurate discrimination of the species within the Anoxybacillus genus than the more commonly used 16S rRNA gene. Furthermore, rapid and reproducible repetitive extragenic palindromic fingerprinting techniques (REP-, ERIC-, and BOX-PCR) were employed for the specimens of genus Anoxybacillus. Through comparison of the three methods, it was found that the BOX-PCR method generated more informative results than REP-PCR for the studied strains; BOX-PCR profiles were more distinct for the different strains, including a higher number of bands. Rapid and reproducible repetitive extragenic palindromic fingerprinting techniques (rep-PCR) constitute a suitable molecular approach for the validation and maintenance of taxonomy within the Anoxybacillus genus. The results of this study show that rpoB and rep-PCR provide rapid and reliable methods for molecular typing of Anoxybacillus species.  相似文献   

9.
Morphological revision of Fulvifomes robiniae, as well as phylogenetic inferences based on nITS and nLSU markers, indicated that the species has a narrower concept in its morphology and distribution. Other morphologically related taxa arise from this taxonomic approach. Fulvifomes cedrelae is not accepted as a synonym of F. robiniae, and Fulvifomes squamosus sp. nov. is described as new based on Peruvian specimens. Based on morphology, phylogenetic relationships and host distributions, the taxonomic implication for the genus and other related taxa are discussed.  相似文献   

10.
The subclass Microbotryomycetidae (Basidiomycota, Urediniomycetes) comprises a remarkably diverse assemblage of fungi. This group includes phytoparasites, mycoparasites and probably also saprobes that show a wide range of ecological preferences. In order to study the phylogenetic relationships within the Microbotryomycetidae, and to develop a more natural classification system, mitosporic and meiosporic taxa were investigated using an integrated approach. Sequence data of 26S rDNA D1/D2 domains were analyzed using several procedures, including the Bayesian Markov chain Monte Carlo method of phylogenetic inference. Ultrastructural markers such as the type of septal pore and presence / absence of colacosomes were investigated and micromorphological and nutritional properties were compared. In this study the current concept of the genus Leucosporidium and its apparent polyphyletic nature were addressed, as well as the relationships of this genus with the Microbotryales and Mastigobasidium. The classification of the anamorphic species closely related to Leucosporidium, and the concepts of the order Sporidiales and family Sporidiobolaceae were also reviewed.  相似文献   

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The phylum Fibrobacteres currently comprises one formal genus, Fibrobacter, and two cultured species, Fibrobacter succinogenes and Fibrobacter intestinalis, that are recognised as major bacterial degraders of lignocellulosic material in the herbivore gut. Historically, members of the genus Fibrobacter were thought to only occupy mammalian intestinal tracts. However, recent 16S rRNA gene-targeted molecular approaches have demonstrated that novel centres of variation within the genus Fibrobacter are present in landfill sites and freshwater lakes, and their relative abundance suggests a potential role for fibrobacters in cellulose degradation beyond the herbivore gut. Furthermore, a novel subphylum within the Fibrobacteres has been detected in the gut of wood-feeding termites, and proteomic analyses have confirmed their involvement in cellulose hydrolysis. The genome sequence of F. succinogenes rumen strain S85 has recently suggested that within this group of organisms a “third” way of attacking the most abundant form of organic carbon in the biosphere, cellulose, has evolved. This observation not only has evolutionary significance, but the superior efficiency of anaerobic cellulose hydrolysis by Fibrobacter spp., in comparison to other cellulolytic rumen bacteria that typically utilise membrane-bound enzyme complexes (cellulosomes), may be explained by this novel cellulase system. There are few bacterial phyla with potential functional importance for which there is such a paucity of phenotypic and functional data. In this review, we highlight current knowledge of the Fibrobacteres phylum, its taxonomy, phylogeny, ecology and potential as a source of novel glycosyl hydrolases of biotechnological importance.  相似文献   

13.
The genus Phlomis is one of the largest genera of subfamily Lamioideae (Lamiaceae) with more than 100 recognised species distributed in Asia, southern Europe and northern Africa. Morphological studies have suggested that the species can be split into two morphologically distinct groups that have previously been recognised as either sections or separate genera. The current study represents the first molecular phylogenetic study of the genus in which taxa representative of the entire genus are included. In contrast to considerable morphological and ecological variation among taxa, sequence variation in the trnL intron, the trnLF intergenic spacer, and the rps16 intron was low, resulting in sparse phylogenetic resolution, particularly among the South West Asian and Mediterranean taxa. However, the results support a split of the genus into two separate groups that are recognised here as the genera Phlomoides and Phlomis in order to decrease taxonomic complexity. The close relationship between Phlomis s.l. and Eremostachys, pointed out by several authors, is confirmed, and in a noteworthy new finding, the small Asian genus Notochaete, is more closely related to the Phlomis s.l. lineage than previously assumed. The two monotypic genera Pseuderemostachys and Lamiophlomis as well as Notochaete hamosa are transferred to Phlomoides and three new combinations are made. Character optimisation analyses based on geographic distributions of all taxa show that the groups obtained by molecular phylogenetic analysis correlate well with biogeography. The results suggest that the Phlomis s.l. lineage has a Central Asian origin in an area around Western China.  相似文献   

14.
A new hyphomycetous fungus, Micronematobotrys verrucosus, isolated as an endophyte from Quercus liaotungensis and Ulmus macrocarpa in the Dongling Mountain of Beijing is described as a new monotypic genus represented by M. verrucosus. This new species differs morphologically from Botrytis-like fungi and other similar genera in possessing micronematous conidiophores and colored verrucose conidia. The phylogenetic relationships of Micronematobotrys among sexual ascomycetes are examined based on 18S and 28S rDNA sequence data using maximum parsimony and Bayesian methods. The phylogenetic analyses suggest that M. verrucosus is a member of Pyronemataceae in Pezizales.  相似文献   

15.
A new species, Strobilomyces verruculosus, is described and illustrated. It is morphologically distinct from other species of Strobilomyces by having a verruculose pileus with small subpyramidal scales, a long and thick stipe with small warty to appressed scales, subdecurrent tubes, and incompletely reticulate basidiospores. Molecular phylogenetic analyses using the mitochondrial cytochrome oxidase subunit 3 (cox3) gene support that it belongs to the genus Strobilomyces and is highly differentiated from the other members of this genus found in Japan.  相似文献   

16.
Chloroplast DNA sequences and microsatellites are useful tools for phylogenetic as well as population genetic analyses of plants. Chloroplast microsatellites tend to be less variable than nuclear microsatellites and therefore they may not be as powerful as nuclear microsatellites for within-species population analysis. However, chloroplast microsatellites may be useful for phylogenetic analysis between closely related taxa when more conventional loci, such as ITS or chloroplast sequence data, are not variable enough to resolve phylogenetic relationships in all clades. To determine the limits of chloroplast microsatellites as tools in phylogenetic analyses, we need to understand their evolution. Thus, we examined and compared phylogenetic relationships of species within the genus Clusia, using both chloroplast sequence data and variation at seven chloroplast microsatellite loci. Neither ITS nor chloroplast sequences were variable enough to resolve relationships within some sections of the genus, yet chloroplast microsatellite loci were too variable to provide any useful phylogenetic information. Size homoplasy was apparent, caused by base substitutions within the microsatellite, base substitutions in the flanking regions, indels in the flanking regions, multiple microsatellites within a fragment, and forward/reverse mutations of repeat length resulting in microsatellites of identical base composition that were not identical by descent.  相似文献   

17.
The relationship between Litsea and related genera is currently unclear. Previous molecular studies on these taxa using cpDNA and nrITS were unable to produce well-resolved phylogenetic trees. In this study, we explored the potential of the rpb2 gene as a source of molecular information to better resolve the phylogenetic analysis. Although rpb2 was believed to be a single-copy gene, our cloning results showed that most species examined possessed several copies of these sequences. However, the genetic distance among copies from any one species was low, and these copies always formed monophyletic groups in our molecular trees. Our phylogenetic analyses of rpb2 data resulted in better resolved tree topologies compared to those based on cpDNA or nrITS data. Our results show that monophyly of the genus Litsea is supported only for section Litsea. As a genus, Litsea was shown to be polyphyletic. The genera Actinodaphne and Neolitsea were resolved as monophyletic groups in all analyses. They were also shown to be sisters and closer to the genus Lindera than to the genus Litsea. Our results also revealed that the genus Lindera is not a monophyletic group.  相似文献   

18.
Phylogenetic relations within the genus Gordonia were analyzed using partial gyrB and secA1 gene sequences of 23 type species in comparison with those of 16S rRNA gene. The gyrB and secA1 phylogenies showed agreement with that constructed using 16S rRNA gene sequences. The degrees of divergence of the gyrB and secA1 genes were approximately 3.4 and 1.7 times greater, respectively, than that of 16S rRNA gene. The gyrB gene showed more discriminatory power than either the secA1 or 16S rRNA gene, facilitating clear differentiation of any two Gordonia species using gyrB gene analysis. Our data indicate that gyrB and secA1 gene sequences are useful as markers for phylogenetic study and identification at the species level of the genus Gordonia.  相似文献   

19.
Rallidae, with 34 genera including 142 species, is the largest family in the Gruiformes, the phylogenetic placement of this family was still in debate. The complete mitochondrial genomes (mitogenomes), with many advantageous characters, have become popular markers in phylogenetic analyses. We sequenced the mitogenomes of brown crake (Amaurornis akool) and white-breasted waterhen (Amaurornis phoenicurus), analyzed the genomic characters of mitogenomes in Rallidae, and explored the phylogenetic relationships between Rallidae and other four families in Gruiformes based on mitogenome sequences of 32 species with Bayesian method. The mitogenome of A. akool/A. phoenicurus was 16,950/17,213 bp in length, and contained 37 genes typical to avian mitogenomes and one control region, respectively. The genomic characters of mitogenomes in Rallidae were similar. The phylogenetic results indicated that, among five families, Rallidae had closest relationship with Heliornithidae, which formed a sister taxa to Gruidae, while Rhynochetidae located in the basal lineage. Within Rallidae, Rallina was ancestral clade. Gallirallus & Rallus and Aramides were closely related, Gallicrex & Amaurornis and Fulica & Gallinula had close relationships, and these two taxa formed a sister clade to Porphyrio & Coturnicops. Our phylogenetic analyses provided solid evidence for the phylogenetic placement of Rallidae and the evolutionary relationships among different genus within this family. In addition, the mitogenome data presented here provide useful information for further molecular systematic investigations on Gruiformes as well as conservation biology research of these species.  相似文献   

20.

Background  

Rosids are a major clade in the angiosperms containing 13 orders and about one-third of angiosperm species. Recent molecular analyses recognized two major groups (i.e., fabids with seven orders and malvids with three orders). However, phylogenetic relationships within the two groups and among fabids, malvids, and potentially basal rosids including Geraniales, Myrtales, and Crossosomatales remain to be resolved with more data and a broader taxon sampling. In this study, we obtained DNA sequences of the mitochondrial matR gene from 174 species representing 72 families of putative rosids and examined phylogenetic relationships and phylogenetic utility of matR in rosids. We also inferred phylogenetic relationships within the "rosid clade" based on a combined data set of 91 taxa and four genes including matR, two plastid genes (rbcL, atpB), and one nuclear gene (18S rDNA).  相似文献   

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