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1.
The genus Philodendron (Araceae) is a large neotropical group whose classification remains unclear. Previous classifications are based on morphological characters, mainly from the inflorescence, flower and leaf shape. The classification by Krause, with few modifications, is still the most commonly used system. To examine phylogenetic relationships in the genus, two ribosomal DNA nuclear markers, internal transcribed spacer (ITS) and external transcribed spacer (ETS), and the chloroplast intron rpl 16, were sequenced and analysed for more than 80 species of Philodendron and its close relative Homalomena . According to the resulting phylogeny, the genus Homalomena may be paraphyletic to the genus Philodendron . The inclusion of the American Homalomena species within the genus Philodendron might resolve this taxonomic problem. All three subgenera of Philodendron were revealed as monophyletic. Below the subgeneric level, the groups obtained in our phylogeny globally correspond to sections recognized in previous classifications. Among the morphological characters used by previous taxonomists to build their classifications, and which we optimized onto one of the most parsimonious trees, most characters were found to be homoplasious. However, leaf shape, characteristics of the sterile zone on the spadix and venation patterns are useful for delimiting subgenera and sections within the genus.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 13–27.  相似文献   

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Previous phylogenetic analyses of Orchidaceae subtribe Orchidinae resulted in the proposal to classify Coeloglossum viride (L.) Hartman within the genus Dactylorhiza in order to maintain its monophyly. In this paper, we report some results that contradict previous studies regarding the monophyly of the traditional Dactylorhiza and its phylogenetic relationship with Coeloglossum. Our results, which combine sequences of the internal and external transcribed spacers of the nuclear ribosomal DNA, support the monophyly of Dactylorhiza , with Coeloglossum being a sister clade. The position of C. viride in the phylogenetic tree, and the considerable morphological differences with respect to Dactylorhiza , incline us to retain both lineages as distinct genera.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 261–269.  相似文献   

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Recent molecular phylogenetic studies of the terrestrial snail genus Albinaria have caused a radical reassessment of its taxonomy. These studies, however, were limited to western species. This paper examines mitochondrial 12S sequences and nuclear ITS1 & 2 sequences of both eastern and western species, and demonstrates that Albinaria, in its most recent definition, is not monophyletic. Both molecular datasets place ' Albinaria ' hedenborgi from Lebanon in a well-supported clade with species of the genus Cristataria , distributed south-east of the vicariant range of Albinaria . The remaining species from Cyprus, Turkey and Greece constitute a well-supported monophyletic group. These two clades form geographical clusters, whereas Albinaria in the current definition (including ' A. '  hedenborgi ) has a disjunct distribution. ' A.' hedenborgi should therefore be classified with Cristataria , together with the morphologically similar and geographically close ' A. '  nadimi .  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 143 , 531−542.  相似文献   

6.
The cladistic relationships of endemic Commidendrum (four species) and Melanodendron (one species) from St Helena were inferred from sequences of ITS1 and ITS2 of nuclear ribosomal DNA. Despite showing a range of morphological and ecological variation, the four species of Commidendrum , C. spurium , C. robustum , C. rotundifolium , and C. rugosum , form a closely related monophyletic group with percentage sequence divergence between 0.2 and 0.9%. Melanodendron integrifolium is sister to Commidendrum indicating that the two genera may have evolved from a common ancestor that arrived in St Helena via a single dispersal event. The closest relatives of Commidendrum and Melanodendron appear to be South African, in the predominantly shrubby genus Felicia , although further sampling of South African Astereae is required. We discuss the evolution and adaptive radiation of these rare and threatened species with particular reference to the possible role of heterochrony.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 69–83.  相似文献   

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Phylogenetic relationships among nine genera and 28 species of the southern African tribe Podalyrieae were estimated from sequences of the internal transcribed spacer (ITS) of nuclear ribosomal DNA as well as morphological and chemical data. Morphological and ITS sequence data produced cladograms with similar topologies, both supporting the monophyly of Podalyrieae (excluding Hypocalyptus ). The combined data sets indicate that subtribe Xiphothecinae are monophyletic, but embedded within Podalyriinae. The high degree of congruence between previous taxonomic hypotheses and those based on DNA data provides further evidence for the utility of ITS sequences in studying phylogeny.  © 2002 The Linnean Society of London , Botanical Journal of the Linnean Society , 2002, 139 , 159–170.  相似文献   

9.
Lespedeza (tribe Desmodieae, Fabaceae) follows a disjunct distribution in eastern Asia and eastern North America. Phylogenetic relationships among its species and related taxa were inferred from nuclear ribosomal internal transcribed spacer (ITS) and plastid sequences (trnH‐psbA, psbK‐psbI, trnK‐matK and rpoC1). We examined 35 species of Lespedeza, two of Kummerowia and one of Campylotropis, the sole constituents of the Lespedeza group. An analysis of these data revealed that the genus Campylotropis is sister to the other two genera. However, we were unable to resolve the relationships between Kummerowia and Lespedeza in the strict consensus trees of parsimony analyses based on plastid and combined DNA data. In the genus Lespedeza, the Old World subgenus Macrolespedeza is monophyletic, whereas the transcontinental subgenus Lespedeza is paraphyletic. Monophyly of eastern Asian species and of North American species is strongly supported. Although inconsistent with the traditional classification, this phylogenetic finding is consistent with seedling morphology. Three subgroups recognized in subgenus Macrolespedeza were unresolved in our phylogenetic trees. An incongruence length difference (ILD) test indicated that the two partitions (nuclear ITS and plastid sequences) were significantly incongruent, perhaps because of hybridization between species in Lespedeza. Most of the primary clades of tribe Desmodieae are Asian, implying that the relatively few New World ones, such as those in Lespedeza, are more recently derived from Asia. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 164 , 221–235.  相似文献   

10.
Sequence analysis of the internal transcribed spacer (ITS) of the 18S(ITS1)-5.8S-26S(ITS2) rDNA region was performed in order to analyse the phylogenetic relationships between 13 Patagonian species of the genus Berberis (Berberidaceae). The divergence values between the pairwise sequence in the studied Patagonian species were in the range 2.9–22.9%. The lengths of the ITS1 and ITS2 sequences were in the range 227–231 bp and 220–224 bp, respectively, and the 5.8S sequence was 159 bp throughout all species . B. microphylla sensu Landrum does not appear to be monophyletic based on current sampling. Indeed, we suggest that B. microphylla should be distinguished from B. buxifolia , B. parodii , and B. heterophylla . ITS sequences, together with data obtained from morphological, biochemical, amplified fragment length polymorphism, and cytological characterizations, support the existence of diploid and polyploid hybrid speciation in the genus.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 321–328.  相似文献   

11.
The aim of the present work was to clarify the origin and phylogenetic position of the species belonging to the genus Ilex (Aquifoliaceae), especially the South American species. Phylogenetic relationships of the genus Ilex were investigated using the plastid psbA‐trnH intergenic spacer and parsimony and Bayesian analyses. The psbAtrnH intergenic spacer was shown to evolve slowly within Ilex, but a major gap present in this region was useful in the phylogenetic study of the genus. To obtain more potentially parsimonious characters, atpB‐rbcL intergenic spacer data were combined with those for psbA‐trnH. Many gaps present in the psbA‐trnH region were useful in the phylogenetic study of the genus Ilex. The topology of the trees showed that, in general, the clades are strongly related to geographical areas, a fact especially evident in certain different Asian lineages. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 182–193.  相似文献   

12.
The phylogenetic relationships of 27 north-eastern Atlantic and Mediterranean blennioids are analysed based on a total of 1001 bp from a combined fragment of the 12S and 16S mitochondrial rDNA. The most relevant results with implications in current blenniid taxonomy are: (1) Lipophrys pholis and Lipophrys (=  Paralipophrys ) trigloides are included in a well-supported clade that by the rule of precedence must be named Lipophrys ; (2) the sister species of this clade are not the remaining species of the genus Lipophrys but instead a monotypic genus comprising Coryphoblennius galerita ; (3) the smaller species of Lipophrys were recovered in another well-supported and independent clade, which we propose to be recognized as Microlipophrys ; (4) although some authors included the genera Salaria and Lipophrys in a single group we have never recovered such a relationship. Instead, Salaria is more closely related to the genera Scartella and Parablennius ; (5) the genus Parablennius , which was never recovered as a monophyletic clade, is very diverse and may include several distinct lineages; (6) the relative position of Aidablennius sphynx casts some doubts on the currently recognized relationships between the different blenniid tribes. Meristic, morphological, behavioural and ecological characters support our results and are also discussed. The possible roles of the tropical West African coast and the Mediterranean in the diversification of blenniids are discussed.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 86 , 283–295.  相似文献   

13.
Erysimum includes 150–350 species distributed in the Northern Hemisphere, with Eurasia being the centre of greatest diversity. It is well known for its taxonomic complexity as a result of overlapping morphological characters. We present the first densely sampled phylogenetic analysis of Erysimum using internal transcribed spacer (ITS) DNA sequences from c. 85% of the species (117 for the first time), representing the full range of morphological variation and geographical distribution. We used several approaches to reconstruct phylogenetic relationships, dating of diversification and patterns of evolution of morphological characters in the genus. Ancestral‐state reconstructions of four morphological diagnostic characters were performed using maximum parsimony, maximum likelihood and Bayesian methods. Our phylogenetic framework strongly supports the monophyly of Erysimum and recovers some well‐supported clades that are geographically, rather than morphologically, correlated. Our study confirms the placement of Erysimum in lineage I and reveals two Malcolmia spp. (M. maritima and M. orsiniana) as its sister taxa. The results suggest that the biennial duration and caespitose habit (vs. annual or perennial duration and herbaceous or woody habit) and large, yellow, glabrous (vs. small, non‐yellow, pubescent) petals are ancestral in Erysimum. The ancestral‐state reconstruction results show that annual vs. perennial and woody vs. herbaceous features have been independently derived several times. The dating analyses suggest an early radiation of Erysimum during the late Pliocene or early Pleistocene. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175 , 497–522.  相似文献   

14.
The Compositae (Asteraceae) is the largest flowering plant family if described, accepted taxa are considered. Recent revisions in the taxonomy of the family have resulted in the recognition of ten subfamilies and 35 tribes. The tribe Arctotideae is one of the smallest, with around 200 species; it contains two subtribes and several hard-to-place taxa. Previous work has shown that the subtribe Arctotidinae is well defined and is restricted to southern Africa, except for the Australian genus Cymbonotus . Molecular data from internal transcribed spacer (ITS), ndh F, and trn L-F sequences were used (24 previously published sequences; 47 new sequences) to determine the patterns of relationships within the subtribe. Twenty-three samples from the ingroup, including members of all genera and all three species of Cymbonotus , were included in the analysis, together with two outgroup taxa. Cymbonotus is monophyletic and deeply embedded in the subtribe; Haplocarpha is paraphyletic and basal in position; all other genera are monophyletic; however, Arctotis has over 60 species and only eight were sampled for this study, so additional work may prove otherwise. Arctotis is nested high in the tree and has short branch lengths; this may reflect recent radiation. By contrast, the species of the paraphyletic and basal Haplocarpha have long branches, which may indicate an older radiation and a shared ancestry with the remainder of the subtribe. The presence of Cymbonotus in Australia is most probably the result of long-distance dispersal.  Journal compilation © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 1–8. No claim to original US government works  相似文献   

15.
The pulmonate snails of the genus Biomphalaria are widely distributed in the tropics, and they are intermediate hosts of the digenean trematode Schistosoma mansoni that causes intestinal schistosomiasis in humans. Recent molecular evidence suggests that Biomphalaria originated in South America, and following a recent transatlantic migration colonized Africa, where it radiated into the currently recognized 12 species. In the present study we further investigate the internal phylogenetic relationships of African Biomphalaria with emphasis on the dispersal and speciation on the continent, especially in the Great Lakes in East Africa. Our results, based on 16S ribosomal DNA, cytochrome oxidase subunit I (COI), and ribosomal internal transcribed spacer I (ITS1), support the monophyly of an African clade with two separate lineages ( Biomphalaria pfeifferi / Biomphalaria camerunensis and the Nilotic species complex/ Biomphalaria angulosa ). Following the initial colonization of Africa, Biomphalaria spread towards the east where a later radiation occurred in the Lake Victoria basin and the Albertine Rift Valley Lakes. With further dispersal along the River Nile, additional speciation took place giving origin to the North-east African species Biomphalaria alexandrina . Our results present almost no support of the species groups of Mandahl-Barth (except for the pfeifferi group), which is in accordance with other molecular appraisals. Our results suggest that Biomphalaria stanleyi , which is endemic to Lake Albert, is not an ecophenotype of the continental B. pfeifferi as previously suggested by other molecular studies. B. angulosa is sequenced for the first time and it is inferred to have an important phylogenetic position as sister group to the Albertine Rift/Lake Victoria basin radiation.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 151 , 337–349.  相似文献   

16.
Bunium is unusual in Apiaceae in having a variable cotyledon number and broad infrageneric dysploidy. To test the monophyly of the genus, phylogenetic relationships among 39 Bunium species were investigated with DNA sequence data from nuclear (nrITS) and plastid (psbA‐trnH intergenic spacer) regions. Several other taxa with a similar ecology and geography were also included in the analyses. Our results suggest that Bunium is not monophyletic. Bunium spp. in the eastern part of the study area are more closely related to the Central Asian genera Elaeosticta, Galagania, Hyalolaena, Mogoltavia and Oedibasis than to those in the western part. Our study revealed that molecular, morphological (cotyledon number and width of fruit commissure) and karyological data reveal similar patterns in the taxa studied. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 149–170.  相似文献   

17.
We address the generic limits of Gnidia (Thymelaeaceae) through a phylogenetic analysis of nuclear ribosomal DNA internal transcribed spacer (ITS) and plastid rbcL, trnL intron and trnL‐F intergenic spacer regions. Maximum parsimony and Bayesian inference were used to produce trees and assess internal support. The most significant conclusion drawn from the molecular analysis is that Gnidia is polyphyletic as currently circumscribed, comprising at least four distinct lineages that are each related to other genera within Thymelaeoideae. Gnidia pinifolia and G. racemosa are members of a clade within which Struthiola is embedded; a second group of species allies with Drapetes as sister to Passerina; and a third lineage corresponds to the previously recognized genus Lasiosiphon. The remaining species of Gnidia included in this study are allied with the Australian genus Pimelea. The taxonomic implications of these findings are discussed in relation to the principle of monophyly. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 402–417.  相似文献   

18.
Representatives of the genus Praomys occur throughout the African intertropical zone. It is unclear how many species this genus contains, nor do we know the exact distribution ranges and phylogenetic relationships of these taxa. Using molecular (16S rRNA gene sequencing) and morphological (multivariate craniometry) analyses we clarify the taxonomy and phylogenetic relationships among the Praomys occurring in Africa's lowland tropical rainforests. We studied most species known from this area, based on specimens collected in seven countries (Guinea, Ivory Coast, Cameroon, Central African Republic, Gabon, Congo Republic and Democratic Republic of Congo). In our study, Praomys appears to be monophyletic. Our results identify two species complexes: the jacksoni complex includes at least two species ( P. jacksoni and P. mutoni ) and the tullbergi complex contains at least four species ( P. tullbergi , P. rostratus , P. misonnei , P. petteri ). Although the 16S rRNA gene appears insufficient to resolve the phylogenetic relationships among all the members of the tullbergi species complex, it is suitable for the identification of most of the studied species, and its use has allowed us to redefine the geographical limits of several species.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 145 , 539–553.  相似文献   

19.
Phylogenetic relationships of 64 freshwater Barbus s.s. species distributed in basins around the Mediterranean Sea were assessed using cytochrome b sequences. Our results are in concordance with previous morphological and genetic studies, which proposed that these species belong to two major lineages (or subgenera): Barbus and Luciobarbus . We were particularly interested in phylogenetic relationships among species of the Luciobarbus lineage that are primarily found in the southern Mediterranean region from the Iberian Peninsula to the Middle East. In the Luciobarbus lineage, species that were previously attributed to the Capoeta genus were clustered. In this study, we observed short internodes between monophyletic groups having a geographical agreement around the Mediterranean. However, groups from the opposite sides of the Mediterranean Sea (Iberian Peninsula– Capoeta , north-western Africa–Middle East) seem to be phylogenetically close. We therefore infer that rapid radiation of Luciobarbus species in the Late Miocene better fits our data rather than gradual founder events in the southern Mediterranean. We propose that the biogeographical event along an east–west route, responsible for the present distribution of Luciobarbus species, was the 'Lago Mare' phase of the Mediterranean Sea that provided a rapid dispersal route over extensive distances. This provides new insights into the speciation pattern of this group, and may be of general use in the study of freshwater species in these regions.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 80 , 207–222.  相似文献   

20.
The leafy spurges, Euphorbia subgenus Esula, have one of their diversity centres in the Mediterranean, which is considered to be one of the 25 biodiversity hot‐spots. The eastern Mediterranean, in particular, is characterized by its high species richness and is therefore considered to be a cradle for lineage diversification. However, the area remains neglected in phylogenetic studies. Using nuclear ribosomal internal transcribed spacer (ITS) and plastid trnTtrnF sequences, we explored the phylogenetic relationships in the predominantly eastern Mediterranean E. hierosolymitana group, which is characterized by a woody habit. The widespread shrublets E. acanthothamnos, E. glabriflora and E. spinosa, which are similar in habit, are not most closely related, the last two forming a sister clade to other taxa. From the E. acanthothamnos alliance, dendroid shrubs evolved at least two, but possibly four, times, giving rise to widespread E. bivonae and E. hierosolymitana, the Cretan endemic E. sultan‐hassei and the here newly described and genetically most divergent E . lemesiana , endemic to Cyprus. We provide a taxonomic treatment and morphological comparison with the similar, but not most closely related, E. hierosolymitana. Our study underlines the phytogeographical peculiarity of Cyprus and contributes to our current knowledge on the diversification patterns in the eastern Mediterranean. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 295–307.  相似文献   

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