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1.
Species delimitation in Cystoderma and Cystodermella was evaluated based on ITS and LSU rDNA sequences as well as morphological data. Two species of Cystoderma are synonymised with C. carcharias and three species with C. jasonis, distinguishing the synonymised taxa as varieties of these accepted species. Analyses of partial LSU rDNA sequences revealed Cystoderma and Cystodermella as distinct monophyletic genera, with Ripartitella representing a well-supported sister group of the latter. Phaeolepiota aurea represents either an unsupported sister group or member of Cystoderma in the phylogenies based on LSU and ITS sequences rDNA data, respectively. The tribe Cystodermateae sensu Singer did not appear monophyletic according to analyses of LSU sequences. On the basis of these data, the phylogenetic relationships among most of the analyzed genera could not be resolved unequivocally.  相似文献   

2.
 To solve problems concerning the status of the taxa described in the genus Sarcocapnos, we have conducted a study using morphological, pollen morphology (light microscopy), cytogenetic and molecular techniques. Focusing on the last technique, we have sequenced ITS-1 and ITS-2 of nuclear rDNA. The species differ basically according to 5 morphological traits (leaf shape, flower spur, corolla colour, corolla size, and crest of the stigmatic surface). The cytogenetic analyses indicated n=16 to be the standard chromosome number. The ITS analyses showed that the genus is monophyletic, defining two main well-supported clades, one containing S. saetabensis and S. enneaphylla, and one containing the rest of the species. In this second clade, S. speciosa, S. pulcherrima, and S. baetica subsp. ardalii are related, as are S. integrifolia, S. crassifolia subsp. crassifolia, and S. crassifolia subsp. atlantis; S. baetica subsp. baetica forms a trichotomy with the foregoing groups. S. speciosa is shown to be a species separate from S. crassifolia subsp. crassifolia, as in the case of S. baetica with respect to S. integrifolia. Palynologically, the parameters used enabled us to establish clear differences between the taxa, often corroborating the macromorphological and genetic data. The flower spur has been reduced several times in different groups of the genus, for which the classifications established on the basis of this trait are paraphyletic. Received July 16, 2002; accepted December 11, 2002 Published online: March 31, 2003  相似文献   

3.
Traditionally classifications of the Urostyloida have been mainly based on morphology and morphogenesis. Recent molecular phylogenetic analyses have been largely based on single‐gene data for a limited number of taxa. Consequently, incongruence has arisen between the morphological/morphogenetic and the molecular data. In this study, the three phylogenetic markers (SSU rDNA, ITS1‐5.8S‐ITS2 region, and LSU‐rDNA) of three urostyloid genera represented by four species (Bakuella granulifera, Anteholosticha monilata, Caudiholosticha sylvatica, and C. tetracirra) were sequenced to investigate their phylogeny. The results show that: (1) all three genera should be regarded as the members of the order Urostyloida within the subclass Hypotrichia, as indicated by morphological characters; (2) phylogenetic analyses and sequence similarities both indicate that neither Anteholosticha nor Caudiholosticha are monophyletic and the systematic assignment of both genera awaits further evaluation; and (3) Bakuella has a closer relationship with Urostyla than with bakuellids (e.g. Apobakuella and Metaurostylopsis), suggesting Bakuella may belong to the family Urostylidae rather than the family Bakuellidae.  相似文献   

4.
Based on 28 taxa, including six species of Phylloporia, and respectively one representative of 17 genera of the Hymenochaetales, a phylogenetic analysis of a region of the large subunit of the nuclear encoded ribosomal DNA was performed. Molecular sequence data as well as morphological and anatomical features show the genus to be monophyletic. Next related to Phylloporia is Fulvifomes. The phylogenetic relationships of Phylloporia are discussed. In addition the genus Phylloporia is monographed; 12 species are accepted and described with a key.  相似文献   

5.
An hypothesis of phylogenetic relationships of Asilidae and its constituent taxa is presented, combining morphological and DNA sequence data in a total evidence framework. It is based on 77 robber fly species, 11 Asiloidea outgroup species, 211 morphological characters of the adult fly, and approximately 7300 bp of nuclear DNA from five genes (18S and 28S rDNA, AATS, CAD, and EF-1α protein-encoding DNA). The equally weighted, simultaneous parsimony analysis under dynamic homology in POY resulted in a single most parsimonious cladogram with a cost of 27,582 (iterative pass optimization; 27,703 under regular direct optimization). Six of the 12 included subfamily taxa are recovered as monophyletic. Trigonomiminae, previously always considered as monophyletic based on morphology, is shown to be non-monophyletic. Two of the three Trigonomiminae genera, Holcocephala Jaennicke, 1867 and Rhipidocephala Hermann, 1926, group unexpectedly as the sister taxon to all other Asilidae. Laphriinae, previously seen in the latter position, is the sister group of the remaining Asilidae. Five other subfamily taxa, i.e. Brachyrhopalinae, Dasypogoninae, Stenopogoninae, Tillobromatinae, and Willistonininae, are also shown to be non-monophyletic. The phylogenetic relationships among the higher-level taxa are partly at odds with findings of a recently published morphological study based on more extensive taxon sampling. The total evidence hypothesis is considered as the most informative one, but the respective topologies from the total-evidence, morphology-only, and molecular-only analyses are compared and contrasted in order to discuss the signals from morphological versus molecular data, and to analyze whether the molecular data outcompete the fewer morphological characters. A clade Apioceridae+Mydidae is corroborated as the sister taxon to Asilidae.  相似文献   

6.
Cladonia subturgida and C. iberica constitute the whole of a Mediterranean problematic species, which shows great morphological polymorphism. A study was carried out in order to delimit the extant taxa within this group. The variability of the group was studied morphologically, chemically and phylogenetically. The phylogeny was based on three loci (ITS rDNA, rpb2 and mtLSU), using Maximum Parsimony and Bayesian analyses. Six chemotypes were identified, the most common one containing atranorin and protolichesterinic acid. Our results prove that C. subturgida and C. iberica constitute a single, morphologically and chemically polymorphic species. The taxonomic rank of C. turgida var. corsicana was also studied based on analyses of morphological, chemical and ITS rDNA data. The new nomenclatural combination, C. corsicana, is proposed.  相似文献   

7.
The tropical Asian taxa of the species‐rich genus Solanum (Solanaceae) have been less well studied than their highly diverse New World relatives. Most of these tropical Asian species, including the cultivated brinjal eggplant/aubergine and its wild progenitor, are part of the largest monophyletic Solanum lineage, the ‘spiny solanums’ (subgenus Leptostemonum or the Leptostemonum clade). Here we present the first phylogenetic analysis of spiny solanums that includes broad sampling of the tropical Asian species, with 42 of the 56 currently recognized species represented. Two nuclear and three plastid regions [internal transcribed spacer (ITS), waxy, ndhF‐rpL32, trnS‐trnG and trnT‐trnF] were amplified and used to reconstruct phylogenetic relationships using maximum likelihood and Bayesian methods. Our analyses show that Old World spiny solanums do not resolve in a single clade, but are part of three unrelated lineages, suggesting at least three independent introductions from the New World. We identify and describe several monophyletic groups in Old World solanums that have not been previously recognized. Some of these lineages are coherent in terms of morphology and geography, whereas others show considerable morphological variation and enigmatic distribution patterns. Tropical Asia occupies a key position in the biogeography of Old World spiny solanums, with tropical Asian taxa resolved as the closest relatives of diverse groups of species from Australia and Africa.  相似文献   

8.
T艾蒂 《菌物学报》1991,10(Z1):59-64
本文报导了中国新记录Cladtna stygtaCladonta maxima,对生长于越南的新种Cladonta ntttda进行了描述。中国过去记载的Cladtna tmshauguCladonta subfurcata是根据错误的鉴定,应从中国地衣志中排除。Cladonta gractlts subsp turbtnata在中国许多省分都很常见。  相似文献   

9.
Previous studies using the nuclear SSU rDNA and partial LSU rDNA have demonstrated that the euglenoid loricate taxa form a monophyletic clade within the photosynthetic euglenoid lineage. It was unclear, however, whether the loricate genera Trachelomonas and Strombomonas were monophyletic. In order to determine the relationships among the loricate taxa, SSU and LSU nuclear rDNA sequences were obtained for eight Strombomonas and 25 Trachelomonas strains and combined in a multigene phylogenetic analysis. Conserved regions of the aligned data set were used to generate maximum‐likelihood (ML) and Bayesian phylogenies. Both methods recovered a strongly supported monophyletic loricate clade with Strombomonas and Trachelomonas species separated into two sister clades. Taxa in the genus Strombomonas sorted into three subclades. Within the genus Trachelomonas, five strongly supported subclades were recovered in all analyses. Key morphological features could be attributed to each of the subclades, with the major separation being that all of the spine‐bearing taxa were located in two sister subclades, while the more rounded, spineless taxa formed the remaining three subclades. The separation of genera and subclades was supported by 42 distinct molecular signatures (33 in Trachelomonas and nine in Strombomonas). The morphological and molecular data supported the retention of Trachelomonas and Strombomonas as separate loricate genera.  相似文献   

10.
With approximately 25 endemic species, the genus Pyrus (pears) is highly diverse in the Caucasus ecoregion. The majority of Caucasian pears inhabit xerophytic open woodlands or similar habitats, to which they display morphological adaptations, such as narrow leaves. The other species, both Caucasian and non‐Caucasian taxa, mainly inhabit mesophytic forests and display broad leaves. Using a representative taxon sampling of Pyrus from the Caucasus, Europe and Asia, we reconstruct phylogenetic relationships in the genus based on multiple plastid regions. We also estimate the divergence times of major clades in Pyrus, reconstruct the evolution of leaf shapes, and discuss the emergence of xeromorphic leaf traits. Our results confirm the monophyly of Pyrus and the existence of two major clades: (a) an E Asian clade with a crown group age of 15.7 (24.02–8.37 95% HPD) My, and (b) a W Eurasian clade that comprises species from Europe, SW Asia and the Caucasus and that displays a slightly younger crown group of 12.38 (19.02–6.41 95% HPD) My. The existing infrageneric classification of Pyrus was found partially incongruent with the inferred phylogenetic trees. Several currently accepted species were not recovered as monophyletic, indicating that current species limits require re‐evaluation. Ancestral character state reconstructions revealed several independent transitions from broad‐ to narrow‐shaped leaves in Pyrus, probably via intermediate‐shaped leaves.  相似文献   

11.
Wolbachia are intracellular prokaryotic endosymbionts associated with a wide distribution of arthropod and nematode hosts. Their association ranges from parasitism to mutualism, and there is growing evidence that Wolbachia can have dramatic effects on host reproduction, physiology, and immunity. Although all Wolbachia are currently considered as single species, W. pipientis, phylogenetic studies reveal about a dozen monophyletic groups, each designated as a supergroup. This study uses 16S rRNA gene sequences to examine the genetic diversity of Wolbachia present in three species of Great Salt Lake brine flies, Cirrula hians, Ephydra gracilis, and Mosillus bidentatus. The brine fly Wolbachia sequences are highly similar, with an average nucleotide sequence divergence among the three species of 0.00174. The brine fly Wolbachia form a monophyletic group that is affiliated with a subset of supergroup B, indicating that this supergroup may be more diverse than previously thought. These findings expand the phylogenetic diversity of Wolbachia and extend their host range to taxa adapted to a hypersaline environment.  相似文献   

12.
This study investigates the genetic and morphological variability of the lichen Cladonia rei inhabiting strongly contaminated postsmelting slag dumps in southern Poland. Altogether, 27 C. rei samples were analysed, including 17 from a single population in one dump. The phylogenetic analysis includes samples of C. rei, outgroup species, and external sequences of Cladonia section representatives from GenBank. Comparative analysis of the internal transcribed spacer (ITS) rDNA sequences revealed the presence of 19 C. rei haplotypes overall, including several of the most frequent, of which 11 are represented by single individuals only. As many as 12 haplotypes were recorded within a single population. Three strongly supported monophyletic clades comprised of specimens from different geographical regions were recovered. Morphometric analysis showed great phenotypic variability within particular clades. Apart from a full range of previously known morphological forms of the species, an additional specific morphotype was recognised in the dumps; however, its representatives do not create a monophyletic group. High genetic variability within a single population suggests that C. rei has a great potential for colonising anthropogenic habitats. This attribute emphasises the role of this lichen as an essential pioneer in the early stages of natural regeneration of such sites.  相似文献   

13.
Thirty species and one variety of Symplocos (Symplocaceae), including all taxa distributed in Japan, were phylogenetically analyzed with DNA sequence data. The evolution of morphological characters is discussed on the basis of the phylogenetic relationships obtained. All species were Asian, except one, S. austromexicana, from Mexico. The nuclear ribosomal internal transcribed spacer (ITS) region and two intergenic spacer regions, between trnL and trnF, and between trnH and psbA of chloroplast DNA were used. The topologies of trees obtained from ITS and the chloroplast intergenic spacers are largely congruent. S. sonoharae, the representative of the subgenus Symplocos in Asia, was sister to all other species. The position of the American species, S. austromexicana, which also belongs to the subgenus Symplocos, was not well resolved. The phylogenetic tree based on combined sequence data largely supports the monophyletic origin of the infrageneric sections proposed earlier. However, the phylogenetic relationship between them is not well resolved, probably due to rapid diversification. The section Palura, a deciduous group, is well defined in the DNA analysis, suggesting its independent status in the genus Symplocos. In spite of their morphological divergence, the three endemic species of the Bonin Islands are monophyletic. The occurrence of curved seeds seems to be homoplastic, scattered over the phylogenetic tree without showing a particular infrageneric relationship.  相似文献   

14.
Lake Baikal, the oldest lake in the world, is home to spectacular biodiversity and extraordinary levels of endemism. While many of the animal species flocks from Lake Baikal are famous examples of evolutionary radiations, the lake also includes a wide diversity of endemic algae that are not well investigated with regards to molecular‐biological taxonomy and phylogeny. The endemic taxa of the green algal order Cladophorales show a range of divergent morphologies that led to their classification in four genera in two families. We sequenced partial large‐ and small‐subunit rDNA as well as the internal transcribed spacer region of 14 of the 16 described endemic taxa to clarify their phylogenetic relationships. One endemic morphospecies, Cladophora kusnetzowii, was shown to be conspecific with the widespread Aegagropila linnaei. All other endemic morphospecies formed a monophyletic group nested within the genus Rhizoclonium (Cladophoraceae), a very surprising result, in stark contrast to their morphological affinities. The Baikal clade represents a species flock of closely related taxa with very low genetic differentiation. Some of the morphospecies were congruent with lineages recovered in the phylogenies, but due to the low phylogenetic signal in the rDNA sequences the relationships within the Baikal clade were not all well resolved. The Baikal clade appears to represent a recent radiation, based on the low molecular divergence within the group, and it is hypothesized that the large morphological variation results from diversification in sympatry from a common ancestor in Lake Baikal.  相似文献   

15.
The phylogenetic relationships among the fishes in the perciform tribe Epinephelini (Serranidae) have long been poorly understood, in large part because of the numerous taxa that must be considered and the large, circumtropical distribution of the group. In this study, genetic data from two nuclear (Tmo-4C4 and histone H3) and two mitochondrial (16S and 12S) genes were gathered from 155 serranid and acanthomorph species as a means of developing a phylogenetic hypothesis using both maximum-likelihood and -parsimony criteria. The maximum-parsimony analysis recovered 675 most parsimonious trees of length 5703 steps (CI = 0.2523, HI = 0.7477, RI = 0.6582), and the maximum-likelihood analysis recovered 1 tree at −lnLikelihood = 28279.58341. These phylogenetic hypotheses are discussed in light of previous morphological evidence to evaluate the evolutionary history of the group and their implications for the currently recognized taxonomy. Our results question the monophyly of the Serranidae, as well as the genera Cephalopholis, Epinephelus, and Mycteroperca as currently defined. The Serranidae is monophyletic only with the exclusion of the genera Acanthistius and Niphon. We propose a revised classification of the tribe Epinephelini that reflects the hypothesized shared ancestry of the group and recognizes 11 genera: Alphestes, Cephalopholis, Dermatolepis, Epinephelus, Gonioplectrus, Hyporthodus (which is resurrected for 11 species of deep-bodied groupers), Mycteroperca (including 7 species heretofore allocated to Epinephelus), Plectropomus, Saloptia, Triso, and Variola.  相似文献   

16.
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   

17.
The taxonomy of the Cladophoraceae, a large family of filamentous green algae, has been problematic for a long time due to morphological simplicity, parallel evolution, phenotypic plasticity, and unknown distribution ranges. Partial large subunit (LSU) rDNA sequences were generated for 362 isolates, and the analyses of a concatenated dataset consisting of unique LSU and small subunit (SSU) rDNA sequences of 95 specimens greatly clarified the phylogeny of the Cladophoraceae. The phylogenetic reconstructions showed that the three currently accepted genera Chaetomorpha, Cladophora, and Rhizoclonium are polyphyletic. The backbone of the phylogeny is robust and the relationships of the main lineages were inferred with high support, only the phylogenetic position of both Chaetomorpha melagonium and Cladophora rupestris could not be inferred unambiguously. There have been at least three independent switches between branched and unbranched morphologies within the Cladophoraceae. Freshwater environments have been colonized twice independently, namely by the freshwater Cladophora species as well as by several lineages of the Rhizoclonium riparium clade. In an effort to establish monophyletic genera, the genera Acrocladus and Willeella are resurrected and two new genera are described: Pseudorhizoclonium and Lurbica.  相似文献   

18.
The phylogenetic relationships of Chalara and allied taxa are studied based on ribosomal DAN sequences. Partial 28S rDNA and 18S rDNA regions from 26 strains were sequenced in this study. These and related sequences from GenBank were analyzed using parsimony and Bayesian analyses. Most of the Chalara species clustered in a strongly supported monophyletic lineage representing Helotiales. However, a few Chalara species appeared closely related to Xylariales. The phylogenetic significance of morphological characters observed in Chalara species are evaluated based on our sequence analyses. Conidial septation, conidial width and conidiophore pigmentation are thought to be indicative in understanding their evolutionary relationships. Sterile setae, which traditionally have been used to delimitate Chaetochalara from Chalara, are phylogenetically insignificant.  相似文献   

19.
Morphologies of pollen and seed surfaces were investigated with SEM technology for eight natural Ophrys taxa collected from southeastern Mediterranean countries and Turkey. The morphometric characteristics ofO. transhyrcana, O. sphegodes, O. epirotica, O. mammosa, O. pseudomammosa, O. oestrifera subsp.oestrifera, O. cornuta, andO. apifera were recorded and compared statistically. In general, the current species could be separated, in detail, according to those characteristics. These findings were also compared with those from recent studies, and were examined in terms of the present neighbouring taxa.  相似文献   

20.
Carminator Shaw is a small genus of parasitic wasps that is mainly distributed in Southeast Asia. Eight species are recognized here, including Carminator coronatus sp.n. and Carminator gracilis sp.n. A data set comprising 54 morphological characters and including all the known species of Carminator, as well as four out‐group taxa (two Cryptalyra spp., one Ettchellsia sp. and one Megalyra sp.), was assembled and analysed. Carminator is retrieved as monophyletic. All weighted analyses place Carminator affinis as the sister group to the rest of the genus. A northern clade comprising species occurring on the Japanese Isles, Taiwan and Vietnam (Carminator japonicus (Carminator gracilis sp.n. (Carminator cavus + Carminator helios))) is strongly supported and nested inside the more southerly distributed species. C. helios is found on Nakanoshima Island, which emerged post‐Pliocene, and so C. helios is considered to have dispersed there via a land‐bridge connection from the Ryukyu Islands. A key to all known species of Carminator is provided.  相似文献   

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