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1.
Forty-five sequences from members of all genera of Asteraceae indigenous to New Zealand and 50 published sequences representing the tribal diversity in the family were analyzed to assess the utility of ITS sequences to resolve phylogenetic relationships. Previous studies using chloroplast DNA sequences and morphology provided support for several clades in the Asteraceae, yet the relationships among some of these were uncertain. The results from ITS analysis were largely consistent with these earlier studies. The New Zealand species are included in at least six clades, most of these corresponding to recognized tribes. Our results have also clarified the tribal affinities of a few anomalous genera. Haastia, previously aligned with the Gnaphalieae or the Astereae, is nested in the Senecioneae. Centipeda, previously included in the Astereae or Anthemideae, emerges near the Heliantheae. The relationships of Abrotanella remain unresolved. Received August 8, 2001 Accepted November 6, 2001  相似文献   

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Li WP  Yang FS  Jivkova T  Yin GS 《Annals of botany》2012,109(7):1341-1357

Background and Aims

The classification and phylogeny of Eurasian (EA) Aster (Asterinae, Astereae, Asteraceae) remain poorly resolved. Some taxonomists adopt a broad definition of EA Aster, whereas others favour a narrow generic concept. The present study aims to delimit EA Aster sensu stricto (s.s.), elucidate the phylogenetic relationships of EA Aster s.s. and segregate genera.

Methods

The internal and external transcribed spacers of nuclear ribosomal DNA and the plastid DNA trnL-F region were used to reconstruct the phylogeny of EA Aster through maximum parsimony and Bayesian analyses.

Key Results

The analyses strongly support an Aster clade including the genera Sheareria, Rhynchospermum, Kalimeris (excluding Kalimeris longipetiolata), Heteropappus, Miyamayomena, Turczaninowia, Rhinactinidia, eastern Asian Doellingeria, Asterothamnus and Arctogeron. Many well-recognized species of Chinese Aster s.s. lie outside of the Aster clade.

Conclusions

The results reveal that EA Aster s.s. is both paraphyletic and polyphyletic. Sheareria, Rhynchospermum, Kalimeris (excluding K. longipetiolata), Heteropappus, Miyamayomena, Turczaninowia, Rhinactinidia, eastern Asian Doellingeria, Asterothamnus and Arctogeron should be included in Aster, whereas many species of Chinese Aster s.s. should be excluded. The recircumscribed Aster should be divided into two subgenera and nine sections. Kalimeris longipetiolata, Aster batangensis, A. ser. Albescentes, A. series Hersileoides, a two-species group composed of A. senecioides and A. fuscescens, and a six-species group including A. asteroides, should be elevated to generic level. With the Aster clade, they belong to the Australasian lineages. The generic status of Callistephus should be maintained. Whether Galatella (including Crinitina) and Tripolium should remain as genera or be merged into a single genus remains to be determined. In addition, the taxonomic status of A. auriculatus and the A. pycnophyllus–A. panduratus clade remains unresolved, and the systematic position of some segregates of EA Aster requires further study.  相似文献   

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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   

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The phylogeny of the four genera of Aizoaceae subfamily Sesuvioideae (Sesuvium, Cypselea, Trianthema and Zaleya) is elucidated employing internal transcribed spacer (ITS) sequences and 23 morphological characters. Phylogenetic analysis based on ITS sequences and a combined molecular-morphological analysis provide largely congruent results. The monophyly of Sesuvioideae and its close relationship to Aizooideae s.l. and Mesembryanthemoideae is confirmed. Zaleya is placed within Trianthema and Cypselea within Sesuvium by ITS analysis, but in the combined analysis, Zaleya forms an unresolved polytomy with the two Trianthema clades and Cypselea, as well as two Sesuvium species, remain unresolved. Sesuvium sesuvioides and S. hydaspicum, previously treated as synonyms, are closely related, but molecular data do not support conspecifity. The Trianthema triquetra complex needs further intensive study because the African T. triquetra sample is closer to the NE African-Arabian T. sheilae than to Australian samples of T. triquetra. The close relationship of four species of Trianthema (T. patellitecta, T. rhynchocalyptra, T. megasperma, and T. pilosa) from Australia based on molecular data is supported morphologically by the exclusive possession of a well-developed indumentum in these taxa.  相似文献   

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Plagiochila sect. Vagae is a large pantropical clade that is characterized morphologically by frequent terminal branching, vegetative distribution by propagules on the ventral surface of the leaves and a capsule wall with thickenings in all layers. Plagiochila corrugata from Brazil is characterized by strongly undulate, toothed leaf margins and represents the only known neotropical species of sect. Vagae with unispiral elaters. Plagiochila cambuena from Madagascar is distinguished by the same features. Maximum likelihood and parsimony analyses of 38 nrDNA ITS sequences of Plagiochila reveal P. corrugata and P. cambuena in a weakly (ML) to well (MP) supported monophyletic lineage within P.  sect.  Vagae . As an outcome of the morphological and molecular investigation, P. cambuena is relegated to the synonymy of P. corrugata. Plagiochila corrugata is placed in a Vagae -subclade with 11 further American species. The range of P. corrugata can be ascribed to long-range dispersal from the Neotropics rather than a Gondwanan distribution. Species from tropical Asia and Africa are placed at the base of the Vagae clade. Branch length within P.  sect.  Vagae points to a sudden radiation.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 469–481.  相似文献   

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Chamaecrista belongs to subtribe Cassiinae (Caesalpinioideae), and it comprises over 330 species, divided into six sections. The section Xerocalyx has been subjected to a profound taxonomic shuffling over the years. Therefore, we conducted a phylogenetic analysis using a cpDNA trnE-trnT intergenic spacer and nrDNA ITS/5.8S sequences from Cassiinae taxa, in an attempt to elucidate the relationships within this section from Chamaecrista. The tree topology was congruent between the two data sets studied in which the monophyly of the genus Chamaecrista was strongly supported. Our analyses reinforce that new sectional boundaries must be defined in the Chamaecrista genus, especially the inclusion of sections Caliciopsis and Xerocalyx in sect. Chamaecrista, considered here paraphyletic. The section Xerocalyx was strongly supported as monophyletic; however, the current data did not show C. ramosa (microphyllous) and C. desvauxii (macrophyllous) and their respective varieties in distinct clades, suggesting that speciation events are still ongoing in these specimens.  相似文献   

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Recent molecular systematic investigations suggested that Ferula, an umbellifer genus of about 170 species, is polyphyletic, with its members placed in the apioid superclade and within tribe Scandiceae. We analyzed ITS sequence variation from 134 accessions of Apiaceae, including 83 accessions (74 species) of Ferula to ascertain the phylogenetic position of the genus within the family. Phylogenetic analyses of these data using maximum parsimony, Bayesian, and neighbor-joining methods support the monophyly of Ferula upon the addition of Dorema and Leutea (as Ferula sensu lato) and its placement in tribe Scandiceae. Ferula sensu is closely allied with other major lineages of Scandiceae, corresponding to subtribes Scandicinae, Daucinae, and Torilidinae. Therefore, we recognize the Ferula clade as subtribe Ferulinae. Another addition to tribe Scandiceae is a clade composed of genera Glaucosciadium and Mozaffariania. The three accessions of Ferula misplaced in the apioid superclade represent a species of Silaum.  相似文献   

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The central Asian endemic Xylanthemum tianschanicum (Krasch.) Muradyan (Compositae, Anthemideae) is the only species of Xylanthemum Tzvelev with radiate capitula. While the species was formerly found to be closely related to members of the subtribe Handeliinae, other representatives of the genus were considered to be similar to members of Tanacetum. In order to assess its phylogenetic relationships and taxonomic classification, a molecular analysis based on ITS sequences of 13 representatives of the subtribe Handeliinae and 17 species of three other subtribes (Anthemidinae, Artemisiinae and Matricariinae) was performed. Due to the close relationship of the X. tianschanicum to the type species of Richteria (Richteria pyrethroides) in a well supported clade (PP = 1, BS = 100%), which is supported by morphological features concerning the indumentum, capitulum morphology, and pappus structure, the combination Richteria tianschanica (Krasch.) Sonboli & Oberpr. is proposed based on the basionym Pyrethrum tianschanicum Krasch.  相似文献   

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ITS and ETS-based sequence analyses of 29 Neolitsea, six Actinodaphne and five outgroup `core' Laureae taxa show that Neolitsea is monophyletic with two large subclades, whereas most of the sampled Actinodaphne are paraphyletic below it. Inflorescence features appear to be among the more reliable morphological characters for explaining relationships between Neolitsea and other genera within the `core' Laureae, with the Neolitsea/Actinodaphne clade defined by inflorescences lacking vegetative terminal buds in the main axis. Although the relationships within Neolitsea are still poorly resolved, there is enough structure to suggest that the genus seems to divide into two groups based on fruit shape: elliptic or ovoid, versus globose, although more evidence (both molecular and morphological) and wider taxon sampling are required to confirm this.  相似文献   

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Phylogenetic relationships among the lygosomine skinks were inferred from 1249 base positions of mitochondrial DNA sequences of 12S and 16S rRNA genes. The monophyly of this subfamily was confirmed and the presence of five distinct infrasubfamilial lineages detected. Of these, the Sphenomorphus group appears to have diverged first, followed by the Lygosoma and Egernia groups in order, leaving the Eugongylus and Mabuya groups as sister groups. Our results did not support monophyly of the Mabuya group sensu lato (i.e., an assemblage of the Lygosoma, Egernia, and Mabuya groups), for which a number of morphological and karyological studies demonstrated a considerable similarity. Our results also contradict the previous hypothesis, formulated on the basis of morphological and immunological data, which argued for the sister relationship between the Egernia and the Eugongylus groups. Morphological and karyological characters used to define the Mabuya group (sensu lato) may actually represent plesiomorphic states. The phylogenetic diversity of lygosomine skinks in the Australian region appears to have increased through multiple colonizations from Southeast Asia.  相似文献   

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应用nrDNA ITS和ETS序列探讨了樟科Lauraceae黄肉楠属Actinodaphne的系统演化关系。对得到的3个序列矩阵(ITS、ETS和ITS/ETS),采用MP(maximum parsimony),ML(maximum likelihood)和Bayesian33分析方法进行了系统发育分析。结果显示,本文选的黄肉楠属Actinodaphne物种与所选的月棒族中的外类群靠近并混和在一起,进一步证实了本属为一个复系类群。结合对传统的形态学性状的重新认识,认为花序类型特征可能是重新界定黄肉楠属的最重要的性状,具有相同化序类型的物种可能具有相同的起源。然而,由于取样数量相对较少以及对矩阵的中.独分析存在一定的差异,还需更详细的研究来验证本文对黄肉楠属系统演化关系的假设,并进一步更精确地重建本属的系统发育关系。  相似文献   

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Background  

The lancelet Asymmetron inferum (subphylum Cephalochordata) was recently discovered on the ocean floor off the southwest coast of Japan at a depth of 229 m, in an anaerobic and sulfide-rich environment caused by decomposing bodies of the sperm whale Physeter macrocephalus. This deep sulfide-rich habitat of A. inferum is unique among the lancelets. The distinguishing adaptation of this species to such an extraordinary habitat can be considered in a phylogenetic framework. As the first step of reconstruction of the evolutionary processes in this species, we investigated its phylogenetic position based on 11 whole mitochondrial genome sequences including the newly determined ones of the whale-fall lancelet A. inferum and two coral-reef congeners.  相似文献   

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Allium is a particularly species rich (more than 800 species) and economically important genus, with numerous taxonomic problems at all levels of classification. In this study, we try to uncover the phylogenetic relationships of the common leek Allium ampeloprasum based on selected samples of this species and its putative relatives in A. sect. Allium from Iran. The silica‐dried leaf samples of 56 accessions representing 23 species of Allium were sequenced; 53 sequences of nrDNA ITS, 35 sequences of plastid rps16 and 52 sequences of trnL–F were generated and additional accessions were extracted from GenBank in order to cover all recognized main lineages in the genus. Maximum Parsimony and Bayesian Inference generated similar trees, but the placement of A. ampeloprasum and its relatives differed slightly between the nuclear and the plastid phylogenies. In the nrITS tree, A. ampeloprasum is retrieved as a highly supported clade with A. iranicum, while in the combined plastid tree A. ampeloprasum formed a highly supported clade with A. vineale. This supports the hypothesis of a possible hybrid origin of A. ampeloprasum. Allium iranicum formed a clade in the plastid tree, but was resolved as paraphyletic in the nrITS tree, probably due to presence of multiple non‐concerted copies of nrITS. Close relationships are suggested between the following species: A. aznavense and A. wendelboi with A. talyschense, A. erubescens and A. rotundum with A. scorodoprasum and A. abbasii with A. phanerantherum.  相似文献   

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This paper assessed the systematic position of the genus Gomphogyne. The nuclear ITS, the chloro-plast rpl16, and trnS-trnR sequences were used to reconstruct the phylogeny of Gomphogyne and its related gen-era. Analyses of three separate and combined datasets provided a good amount of informative characters and re-solved the systematical relationships of Gomphogyne well. The maximum parsimony analyses revealed that: (1) Gomphogyne was a natural genus and was different from the genera Hemsleya and Gynostemma; (2) Hemsleya delavayi and H. macrocarpa did not belong to the genus Gomphogyne, but to the genus Hemsleya; and (3) Gomphogyne was sister to Hemsleya. It was assured that Gomphogyne was a monotypic genus. These results were largely in agreement with the systems of classification of the Cucurbitaceae of Jeffrey in 1990 and in 2005 and with that of Li for Hemsleya in 1993, but were different from the previous studies in which Gomphogyne and Gy-nostemma together were suggested to be sister to Hemsleya.  相似文献   

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The genusMicrosphaera has been considered to be derived from sectionErysiphe of the genusErysiphe by a single event. Cleistothecial appendages are the most distinct difference between the two genera and have an important role for overwintering. To understand the phylogenetic relationship betweenErysiphe sectionErysiphe andMicrosphaera more precisely, phylogenetic trees were constructed using the nucleotide sequences of the rDNA ITS region from 11Erysiphe (sectionErysiphe) and 16Microsphaera taxa. The phylogenetic trees indicated the close relationship between the two genera. However, the generaErysiphe (sectionErysiphe) andMicrosphaera did not group into separate monophyletic lineages; instead, they formed several small clusters that were mixed together. This result suggests that the differentiations of the genera occurred two or more times independently. This also supports the idea that appendage morphology does not always accurately reflect the phylogeny of the powdery mildews because the morphology of appendages may evolve convergently under the selection pressure of their particular biotopes (host plants). Contribution No. 144 from the Laboratory of Plant Pathology, Mie University.  相似文献   

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隙蛛亚科Coelotinae主要分布于东亚地区,其中我国的已有种类占到全世界种数的一半以上,因此对于我国隙蛛类蜘蛛的研究已经成为世界暗蛛科研究的重点之一。隙蛛亚科属于无筛器类群,于1893年,由Cambridge以隙蛛属为模式属而建立,归属于无筛器的漏斗蛛科。之后,虽然经历了数次修订  相似文献   

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