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1.
The flora of Western Europe is rich in endemic species of Apiaceae, many of which have been poorly investigated and whose phylogenetic relationships are poorly known. To investigate relationships among three endemic European genera (Dethawia, Meum, and Rivasmartinezia gen. nov.) and to ascertain their higher-level phylogenetic placements within the subfamily Apioideae, we examined nuclear ribosomal DNA ITS sequences and the plastid trnL-trnF region. Phylogenies estimated using parsimony and Bayesian inference reveal that (1) the historically known “Conioselinum chinense” Clade (Conioselinum chinense; C. scopulorum; Ligusticum canadense; L. porteri; Meum athamanticum; Mutellina purpurea; and Trochiscanthes nodiflora) comprise a strongly supported monophyletic group (100% BS); (2) the genera Dethawia and Meum comprise a strongly supported monophyletic group also included in the “Conioselinum chinense” Clade; and finally (3) a new genus (Rivasmartinezia) with one species (R. vazquezii) from the Northwestern of the Iberian Peninsula, and placed in the basal position in the “Conioselinum chinense” Clade, is described for the family Apiaceae subfamily Apioideae.  相似文献   

2.
The angiosperm Apiaceae tribe Scandiceae includes four major clades—subtribes Daucinae, Ferulinae, Torilidinae, and Scandicinae—that originated ca. 20 Mya. Although all four subtribes are highly supported in molecular analyses, and morphological data indicate a sister relationship between Daucinae and Torilidinae, their branching order has not been resolved using standard Sanger multilocus data. Therefore, in this study, we test the utility of genomic RAD seq data in resolving deep phylogenetic relationships (up to 20 Mya) in Apiaceae subfamily Apioideae, with special emphasis on tribe Scandiceae using 12 representative species. We used two bioinformatic pipelines, pyRAD and RADIS (based on STACKS), to assemble RAD seq data and we tested the influence of various combinations of parameters on the robustness of the inferred tree topologies. Although different data processing approaches produced alignments with various amounts of missing data, they converged to two well‐supported topologies, irrespective of the phylogenetic method applied. Highly supported trees showed Scandicinae as sister to all other clades and indicated that Daucinae and Torilidinae are sister groups, thus confirming the relationship inferred from morphology. We conclude that the RAD seq method can be successfully used to resolve deep relationships formed 20 Mya within Apiaceae. We provide recommendations for parameter settings in RADIS and pyRAD for the analysis of taxa that have accumulated considerable genomic divergence.  相似文献   

3.
The current study represents phylogenetic analyses of Eremurus, Asphodelus and Asphodeline (Xanthorrhoeaceae-Asphodeloideae) using both plastids genome (trnL-F) and the nuclear ribosomal internal transcribed spacer (nrDNA ITS) sequence data. The analyses revealed that each of the investigated genera is monophyletic. Eremurus subgenus Eremurus is monophyletic, whereas the E. subgenus Henningia is paraphyletic. Trachyandra is the closest relative of Eremurus. Bulbinella and Kniphofia are subsequent sisters of Eremurus and Trachyandra. Aloe, Haworthia and Bulbine were nested in a single clade, sister to the last four genera. Asphodeline section Asphodeline appeared to be non-monophyletic, because of the inclusion of A. damascena. All species of Asphodelus analyzed herein, formed a well-supported clade that it is sister to the clade of Asphodeline species.  相似文献   

4.
沼兰族是兰科植物的大族之一,约2000种,除了极地和沙漠地区,全球均有分布.该族植物主要分布在热带地区,尤其在东南亚、热带美洲、非洲以及澳大利亚等地区种类非常丰富.目前,已有关于该族植物形态和分子系统的研究,但有关该族亚族和属间的系统关系尚不清楚,属的界定争议也较大.该文基于核基因片段 ITS 和叶绿体基因片段 mat K 序列,采用最大简约法、最大似然法贝叶斯推理分析法,对现有沼兰族主要属的123种植物和10个外类群植物进行了分子系统学研究.结果表明:沼兰族主要分为3个亚族分支,包括附生的鸢尾兰亚族(Oberoniinae)、地生的羊耳蒜亚族(Liparidinae)和沼兰亚族分支(Crepidium clade).鸢尾兰亚族包括6个属、羊耳蒜亚族分支包括5个属、沼兰亚族分支包括4个属;丫瓣兰亚族(Ypsilorchidinae)应归并为鸢尾兰亚族;Disticholiparis 属与 Stichorkis 属的模式标本相同,应并入 Stichorkis 属;沼兰属(Cre-pidium )和无耳沼兰属(Dienia )的唇瓣结构差异较大,但二者均为单系类群.此外,在收集野外实验材料过程中,发现了2种产自中国西南部和越南北部的沼兰族新种,分别命名为麻栗坡羊耳蒜(Platystyliparis mali-poensis G.D.Tang,X.Y.Zhuang & Z.J.Liu)和秉滔羊耳蒜(Cestichis pingtaoi G.D.Tang,X.Y.Zhuang &Z.J.Liu).  相似文献   

5.
6.
  • Introgression is a poorly understood evolutionary outcome of hybridisation because it may remain largely undetected whenever it involves the transfer of small parts of the genome from one species to another. Aiming to understand the early stages of this process, a putative case from the southernmost border of the Armeria pungens range from its congener A. macrophylla is revisited following the discovery of a subpopulation that does not show phenotypic signs of introgression and resembles typical A. pungens.
  • We analysed morphometrics, nuclear ribosomal DNA ITS and plastid DNA (trnL‐trnF) sequences, genome size, 45S and 5S rDNA loci‐FISH data and nrDNA IGS sequences.
  • Within the study site, most individuals match morphologies of either of the two hybridising species, particularly the new subpopulation, with intermediate phenotypes being scarce. This pattern does not fully fit molecular evidence revealing two ITS ribotypes co‐occurring intragenomically in most plants from the study site and one single plastid haplotype. Genome size and structural features of the IGS sequences both indicate that A. pungens from the study site is genetically more similar to its sympatric congener than to the remainder of its conspecifics.
  • Introgression of A. macrophylla into A. pungens and plastid capture explain all the evidence analysed. However, important features to understand the origin and fate of the introgressed population, such as the degree and direction of introgression, which are important for understanding early stages of hybridisation in plants with low reproductive barriers, should be addressed with new data.
  相似文献   

7.
We studied the morphology and molecular phylogeny of Myoschiston duplicatum, a peritrich ciliate that has been recorded as an epibiont of crustaceans, but which we also identified on marine algae from Korea. The important morphological characteristics revealed by silver staining of Myoschiston species have not been described because they are rarely collected. Using morphological methods, we redescribed the type species of the genus, Myoschiston duplicatum, and provided an improved diagnosis of Myoschiston. In addition, the coding regions for nuclear small subunit (SSU) rRNA and internal transcribed spacer 1‐5.8S‐internal transcribed spacer 2 sequences were sequenced. Phylogenetic analyses that included available SSU rDNA sequences of peritrichs from GenBank strongly supported a position of M. duplicatum within the family Zoothamniidae. In addition, phylogenetic analyses were performed with single datasets (ITS1‐5.8S‐ITS2) and combined datasets (SSU rDNA + ITS1‐5.8S‐ITS2) to explore further the phylogenetic relationship in the family Zoothamniidae between the three morphologically similar genera—Zoothamnium, Myoschiston, and Zoothamnopsis.  相似文献   

8.
ITS of the nrDNA were sequenced for 21 taxa inIxoroideae and outgroups (Rubiaceae) and compared with sequences of the cp-generbcL. Separate and combined analyses were performed. ITS-variation was extensive and, because of alignment ambiguities, some sites were excluded from the analyses. Several topologies from therbcL analysis that conflicted with earlier classifications are corroborated by the ITS data: 1)Posoqueria should be excluded fromGardenieae. 2) The disputed genusBertiera, previously inGardenieae, is basal in an extendedCoffeeae, includingTricalysia. 3)Ixora should be excluded fromPavetteae. 4)Vangueria, (Antirheoideae), belongs toIxoroideae. This affiliation ofAntirheoideae tribes withIxoroideae is also shown by new ITS andrbcL data forAlberta. Incongruities found between the two data sets may be caused by density of taxon sampling, different evolutionary rates, phylogenetic sorting, homoplasy caused by functional constraints, or sampling of non-orthologous ITS types.  相似文献   

9.
Though Berberis (Berberidaceae) is widely distributed across the Eurasian landmass it is most diverse in the Himalaya–Hengduan Mountain (HHM) region. There are more than 200 species in China where it is one of the most common mountain shrubs. The study on the taxonomy and evolution of Berberis in this region can thus provide an important insight into the origin and diversification of its flora. A prerequisite to this is mapping and describing the various species of Berberis in the region – a task that despite recent progress is by no means complete. It is clear that in China there may be a significant number of species still to be described and that even with published species much about their distribution remains to be discovered. As a contribution to the first of these tasks seven new species from the northern Hengduan Mountain of N. Sichuan and S. Qinghai: Berberis chinduensis, Berberis degexianensis, Berberis jiajinshanensis, Berberis jinwu, Berberis litangensis, Berberis longquensis and Berberis riparia, are described here. Differences in overall morphology and especially in floral structures with each other and with similar species of Berberis in the same region are presented. The report is the result of phylogenetic analyses based on plastome and partial nrDNA sequences of both the seven proposed new species and a significant number of similar species already published. Provisional conclusions as to the insights provides on the history of the genetic divergence are discussed.  相似文献   

10.
We investigated the phylogenetic relationships in Tulipa in Turkey using DNA sequences from the plastid trnL‐trnF region and the internal transcribed spacer (ITS) of nuclear ribosomal DNA. We generated trnL‐trnF and nuclear ITS sequences for 11 Tulipa spp. from Turkey and compared the utility of trnL‐trnF and ITS sequences for phylogenetic analysis. Neighbor‐joining, Bayesian and maximum parsimony methods were implemented using the same matrices. Our study of Tulipa based on molecular data revealed congruent results with previous studies. Despite the relatively lower resolution of trnL‐trnF than that of ITS, both sequence matrices generated similar results. Three clades were clearly distinguished, corresponding to subgenera Tulipa, Eriostemones and Orithyia. It is not fully resolved whether Clusianae should be recognized as a separate section of subgenus Tulipa or a distinct subgenus. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172 , 270–279.  相似文献   

11.
Myrtaceae are one of the most species‐rich families of flowering plants in the Neotropics. They include several complex genera and species; Hexachlamys is one of the complex genera. It has not been recognized as a distinct genus and has been included in Eugenia, based on morphological grounds. Therefore, molecular systematic studies may be useful to understand and to help to solve these relationships. Here, we performed a molecular phylogenetic analysis using plastid and nuclear data in order to check the inclusion of Hexachlamys in Eugenia. Plastid (accD, rpoB, rpoC1, trnH‐psbA) and nuclear (ITS2) sequence data were analysed using Bayesian and maximum parsimony methods. The trees constructed using ITS2 and trnH‐psbA were the best able to resolve the relationships between species and genera, revealing the non‐monophyly of Hexachlamys. The molecular phylogenetic analyses were in agreement with previous morphological revisions that have included Hexachlamys in Eugenia. These results reinforce the importance of uniting knowledge and strategies to understand better issues of delimitation of genera and species in groups of plants with taxonomic problems. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172 , 532–543.  相似文献   

12.
pleurum of Apiaceae in China. This paper reports chromosome numbers of six species and two varieties of Bupleurum, and for four species and two varieties their chromosome numbers are reported for the first time. The phylogeny of Bupleurum was investigated based on the ITS region of the nuclear ribosomal DNA (nrDNA) of 14 taxa from the Hengduan Mountains, 3 taxa from the North China (Hebei and Heilongjiang), and 16 taxa from Africa and the Mediterranean region. Varia-tions in chromosome numbers and the ITS sequences were used to infer phylogenetic relationships between Bupleurum species in Hengduan Mountains. The results showed that the Hengduan Mountains might represent one of the frequency and diversity centers for Bupleurum. The ancestors of Bupleurum species in the Hengduan Mountains may be related to the woody B. fruticosum in North Africa, or the species in the western Mediterranean region. It is postulated that the ancestral population migrated into Hengduan Mountains through the Middle East and the Caucasus. Furthermore, the neo-endemic B. mundtii in South Africa appeared to be a close relative of the species in the Hengduan Mountains. In the trend of basic chromosome number evolution, x = 8 should be regarded as the ancestral basic number, while x = 6, 7 as the derived ones. The Bupleurum species in the Hengduan Moun-tains have been undergoing changes in the basic chromosome numbers or the ploidy level. The ITS phylogenetic tree showed that the Chinese species were divided into two clades: one with the basic chromosome number x = 8, and the other with x = 6, 7. The results rejected the previous infrageneric classification of Bupleurum in China. We further suggested to raise B. marginatum var. stenophyllum to species rank based on the combined evidence from morphology, karyology, pollen morphology, and the ITS phylogenetic tree.  相似文献   

13.
Convolvulus boissieri is an edaphic endemic plant which grows in the Baetic ranges always in association with high mountain xeric dolomitic outcrops. As these dolomitic areas appear in a ‘soil‐island’ pattern, the distribution of this species is disjunct. Populations of this species frequently include a low number of individuals, which could have an important impact on their genetic diversity and viability. Convolvulus boissieri provides an excellent opportunity to study the genetic and phylogeographical aspects of species linked to dolomites. We used amplified fragment length polymorphism markers and nuclear (internal transcribed spacer region of the nuclear ribosomal cistron) and plastid sequences (trnL‐trnF, rpl32‐trnL and trnQ‐5′rps16). Data were generated from 15 populations, representing the distribution area of the species. For sequence analysis and estimation of divergence times we also used sequences from other Convolvulus species. Results revealed low intrapopulational genetic diversity and a strong interpopulational structure. Furthermore, we found clear‐cut differentiation caused by the existence of two large population groups separated by the Guadiana Menor river basin. Estimation of divergence times indicated that divergence took place during the Pleistocene glaciations. Genetic diversity and differentiation are similar to those other species exhibiting naturally fragmented distribution with a sky islands pattern. In phylogeographical terms, the successive glaciation–interglaciation cycles caused the species to spread from the western sites to eastern sites, the latter being more exposed to the effects of glaciation. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 176 , 506–523.  相似文献   

14.
横断山区是中国柴胡属Bupleurum植物的分布中心。本文对横断山区6个种2变种进行了染色体记数报道,其中4个种2变种是首次报道。对横断山区的10个种4个变种、中国北方(河北和黑龙江)的3个种的nrDNA ITS进行测序,同时从GenBank里面下载同属的来自非洲和地中海西部的16个nrDNA ITS序列数据,结合染色体数目变化结果,初步探讨了横断山区柴胡属植物的系统发育。结果表明横断山区可能是现代柴胡属植物的频度中心和多样分布中心之一。它们的祖先种可能是非洲北部的木本柴胡属植物B.fruticosum,或者是地中海西部的柴胡属植物,推测是通过中东和高加索扩散而形成的,其中与非洲南部特有种B.mundtii的亲缘关系也较近;染色体基数演化趋势是:8是较原始基数,6和7是次生基数,其染色体异基数变异和多倍化可能是物种形成、进化以及向外扩散的主要方式;在ITS系统发育树中,中国柴胡属植物染色体基数为8的种类聚为一支,染色体基数为6和7的种类聚为了一支,不支持舒璞等(1998)关于中国柴胡属的属下分类系统。结合已有的形态学、细胞学、孢粉学证据和ITS系统发育树,建议窄竹叶柴胡B.marginatum var.stenophyllum独立成种。  相似文献   

15.
A series of recent molecular systematic studies of the African electric fishes (Mormyroidea) have challenged many aspects of their traditional taxonomy and precladistic hypotheses of their phylogeny. However, poor resolution of some interrelationships within the subfamily Mormyrinae in these studies highlights the need for additional data and analyses. Here we evaluate the phylogenetic information content of nucleotide sequences from the first two introns of the low‐copy nuclear S7 ribosomal protein gene in 40 mormyroid species. Alignment of S7 sequences from 38 taxa within the subfamily Mormyrinae is non‐problematic, but these are difficult to align with sequences of Petrocephalus bovei (Petrocephalinae) and Gymnarchus niloticus (Gymnarchidae), which we exclude from our analysis. There are no significant differences in base frequencies among these sequences and base compositional bias is low. Maximum parsimony (MP) analysis on the S7 dataset, designating Myomyrus macrops as the outgroup, generates a phylogenetic hypothesis for these taxa with a low level of homoplasy (RI = 0.87). We examine agreement between the S7 data with previously published mitochondrial (12S/16S, cytochrome b) and nuclear (rag 2) datasets for the same taxa by means of incongruence length difference tests and partitioned Bremer support (decay) analysis. While we find significant agreement between the S7 dataset and the others, MP analysis of the S7 data alone and in combination with the other datasets indicates two novel relationships within the Mormyrinae: (1) Mormyrus is the sister group to Brienomyrus brachyistius and Isichthys henryi, and (2) Hippopotamyrus pictus is the sister group of a clade, previously recovered, containing Marcusenius senegalensis. S7 data provide additional support for a number of clades recovered in the earlier molecular studies, some of which conflict with current mormyrid taxonomy. Inferred indels and a single inversion in the S7 fragment provide supplemental character support for many of these relationships. These phylogenetic results strengthen recent hypotheses concerning the evolution of electric organ structure in these fishes. The evolutionary characteristics of this nuclear marker and its phylogenetic utility in this group suggests that it could be widely useful for systematic studies at the subfamilial level in teleost fishes. © 2003 The Linnean Society of London. Biological Journal of the Linnean Society, 2003, 78 , 273–292.  相似文献   

16.
The taxonomic status of Primula ranunculoides and other members of section Ranunuculoides is reappraised here based on data from morphological, reproductive and molecular characters. Multivariate analysis of morphological characters indicates that P. ranunculoides is a coherent species that can be distinguished from its sectional congeners P. cicutariifolia and P. merrilliana by the characters of simple kidney‐shaped outer leaves and the unique clonal reproductive ability by which apices of the scape differentiate into bulblets at the late phases of flowering. Recognition of P. ranunculoides at the specific level is also supported by palynological characters, breeding system, cross pollination results and molecular phylogenetic analysis of nrDNA internal transcribed spacer sequences. A taxonomic revision of section Ranunuculoides is presented and a possible mechanism of speciation discussed. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169 , 338–349.  相似文献   

17.
A phylogenetic analysis based on a comparison of nucleotide sequences of six regions (petN-psbM, trnD-trnT, trnC-petN, psaA-ycf3, petG-trnP, and rpoB-trnC) of cpDNA and ITS rDNA allowed for elucidating the relationship among species and sections belonging to the Salix subgenus and, more generally, to the Salix genus, as well as revealing the relations of the Chosenia genus. The definition of the subgenera Pleuradenia (including the Urbanianae section and the Chosenia genus), Salix (without the Triandrae section), Triandrae, and Longifoliae is essentially consistent with current classification schemes of the Salix genus. The previously defined genera of Chosenia and Toisusu (Urbanianae) are not only merged with the Salix genus but are also closely related between themselves. The Protitea subgenus only corresponds to the American species of the Humboldtianae section (S. humboldtiana, S. amygdaloides, S. gooddingii). The relationship of S. chaenomeloides, which is a nomenclatural type of this subgenus, as well as the relationship of the Wilsonia section, remains unresolved. The Humboldtianae section should be interpreted more narrowly, apparently, separating Acmophyllae and Tetraspermae sections from it. The monotypic American Floridanae section is related to the Salix, Salicaster, Tetraspermae, and Wilsonia sections.  相似文献   

18.
Sequences of the internal transcribed spacers (ITS) of nuclear ribosomal DNA were determined for 15 species ofIllicium (Illiciaceae) to examine phylogenetic relationships. The ITS trees show a major dichotomy between the two North American species (I. floridanum andI. parviflorum) and the remaining east Asian species. This suggests that the existing division between two sections (sect.Illicium and sect.Cymbostemon) ofIllicium based on tepal characters in unnatural. The ITS phylogeny shows congruence with palynology: of the species examined, the three species (I. angustisepalum, I. anisatum andI. fargesii) from sect.Illicium that possess trizonocolpate pollen consistently form a clade, although nesting within a clade consisting of the species of sect.Cymbostemon, which generally have trisyncolpate pollen. The low ITS sequence divergence and the close relationship among east Asian species suggest a recent diversification of this group of species or an unusual slowdown of sequence mutations.  相似文献   

19.
Species belonging to the dinophyte genus Scrippsiella are frequently reported in marine waters, but information on their distribution in brackish environments is limited. Here we describe a new species, S. plana, through incubation of non-calcified cysts from sediments collected in the South China Sea and Caspian Sea. The vegetative cells consist of a conical epitheca and a rounded hypotheca with the plate formula of Po, X, 4′, 3a, 7′′, 5C+t, 5S, 5′′′, 2′′′′. It differs from other Scrippsiella species by its flattened body in dorsoventral view and a small first anterior intercalary (1a) plate (half the size of plate 3a). Scrippsiella plana strains from the South China Sea and Caspian Sea share identical internal transcribed spacer (ITS) sequences, and show phenotypic plasticity and local adaptation in growth rate at various salinities, consistent with the environments in which they originated. In addition, two strains of S. spinifera were obtained by incubating ellipsoid cysts with calcareous spines from sediments collected along the Turkish and Hawaiian coast. They also share identical ITS sequences and differ from Duboscquodinium collinii (a parasite of tintinnids) only at two base pair positions (in the ITS2 region). Molecular phylogeny based on ITS and large subunit ribosomal DNA (LSU rDNA) sequences revealed that S. plana was nested within the Calciodinellum (CAL) clade and S. spinifera within the S. trochoidea (STR) clade. The phylogenetic position of ‘Peridiniumwisconsinense is reported for the first time, which supports multiple transitions of the Peridiniales to freshwater.  相似文献   

20.
We inferred secondary structure models of the internal transcribed spacers (ITS) 1 and 2 of bush crickets using a combined comparative and thermodynamic approach. The inferred secondary structure models were used to account for interdependency of interacting nucleotides in a phylogenetic analysis of the bush cricket genus Poecilimon. Our analysis indicates that the two previously reported conformational structures (i.e., hairpin and ring) of ITS2 are likely to fold in bush crickets as well and that both predicted structures are similar to those proposed for other eukaryotes. Comparing predicted ITS1 secondary structure models proved to be difficult because of substantial variation in their nucleotide sequence length. Our study revealed that the phylogenetic signal of ITS1 and ITS2 is largely congruent with that preserved in the mitochondrial genes 16S rRNA, tRNA‐Val and 12S rRNA. The phylogenetic signal in both the nuclear and the mitochondrial genome question the monophyly of the genus Poecilimon: species of the genera Poecilimonella, Parapoecilimon, Polysarcus and Phonochorion consistently cluster within Poecilimon.  相似文献   

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