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1.
The phylogeny of the genus Aleochara was previously poorly understood due to difficulties with phylogenetic reconstruction by morphological characters. We present here a phylogeny based on the sequences of a 2022-bp fragment of the COI/II genes; 50 Aleochara and 10 outgroup species were included in the analysis. We used parsimony, minimum-evolution, and maximum-likelihood analyses to infer the phylogeny of the group. Our data do not support the commonly assumed sister group relationship between Aleocharini and Hoplandriini. Aleochara is resolved as a monophylum, although A. clavicornis might not belong to the genus. Within Aleochara, there are two large monophyletic clades. Many of the existing subgenera are shown to be para- or polyphyletic; others are likely to be monophyletic. Tinotus morion, previously assigned to the Hoplandriini, is strongly supported as belonging to Aleochara. According to our data, the mesosternal carina that has been used as an important character for classification has arisen and been reduced independently in several clades within Aleochara.  相似文献   

2.
Although the subfamily Zapodinae (Rodentia, Dipodidae) contains only five species, the phylogeny and taxonomy of these species are still being disputed. First, whether Eozapus and Napaeozapus should be treated as independent genera or subgenera of Zapus has been argued for a long period. Second, the subspecific genetic differentiation of Chinese jumping mouse (Eozapus setchuanus) has not been studied in detail, neither from morphological nor molecular aspects. In this study, the phylogenetic relationship among all the five species of Zapodinae was reconstructed using DNA sequence data from the mitochondrial cytochrome b gene and the nuclear interphotoreceptor retinoid binding protein gene. Bayesian inference, maximum parsimony and maximum likelihood analyses were conducted. The results showed that two major clades could be recognized within Zapodinae. Eozapus setchuanus, is the species endemic to China, strongly formed a monophyletic clade. In the other clade, genus Zapus received significant support in all analyses to be the sister group of the genus Napaeozapus. By comparing genetic distances among these three genera, we conclude that both Eozapus and Napaeozapus should be considered as valid genera rather than subgenera of Zapus. Furthermore, we observed that the two subspecies of E. setchuanus did not form reciprocally monophyletic groups, thus the traditional taxonomy which divided E. setchuanus into two subspecies based on only one morphological character was questionable.  相似文献   

3.
Several members of the dipteran family Tephritdae are serious pests because females lay eggs in ripening fruit. The genus Bactrocera is one of the largest within the family with over 500 described species arranged in 28 subgenera. The phylogenetic relationships among the various species and subgenera, and the monophyly of specific groups have not been examined using a rigorous phylogenetic analysis. Therefore, phylogenetic relationships among 24 Bactrocera species belonging to 9 subgenera were inferred from DNA sequence of portions of the mitochondrial 16S rRNA, cytochrome oxidase II, tRNA(Lys), and tRNA(Asp) genes. Two morphological characters that traditionally have been used to define the four groups within the subgenus Bactrocera were evaluated in a phylogenetic context by mapping the character states onto the parsimony tree. In addition, the evolutionary trend in male-lure response was evaluated in a phylogenetic context. Maximum parsimony analyses suggested the following relationships: (1) the genus Bactrocera is monophyletic, (2) the subgenus B. (Zeugodacus) is paraphyletic, (3) the subgenus B. (Daculus) is a sister group to subgenus B. (Bactrocera), and (4) the subgenus B. (Bactrocera) is monophyletic. The mapping analyses suggested that the morphological characters exhibit a simple evolutionary transition from one character state to another. Male-lure response was identified as being a labile behavior that has been lost on multiple occasions. Cue-lure response was plesiomorphic to methyl-eugenol response, and the latter has evolved independently within the Bactrocera and Zeugodacus groups of subgenera. The implications of our results for devising a coherent, consolidated classification for Bactrocera is discussed.  相似文献   

4.
Sequences of the chloroplast ndhF gene and the nuclear ribosomal ITS regions are employed to reconstruct the phylogeny of Prunus (Rosaceae), and evaluate the classification schemes of this genus. The two data sets are congruent in that the genera Prunus s.l. and Maddenia form a monophyletic group, with Maddenia nested within Prunus. However, the ndhF data set is incongruent with the ITS data supporting two major groups within Prunus one consisting of subgenera Laurocerasus (including Pygeum) and Padus as well as the genus Maddenia and another of subgenera Amygdalus, Cerasus, and Prunus. The ITS data, on the other hand, support a clade composed of subgenera Amygdalus and Prunus and Prunus sect. Microcerasus in addition to a paraphyletic grade of subgenera Laurocerasus and Padus (and the genus Maddenia) taxa. In general, the subgeneric classifications of Prunus s.l. are not supported. The ITS and ndhF phylogenies differ mainly in interspecific relationships and the relative position of the Padus/Laurocerasus group. Both ITS and ndhF data sets suggest that the formerly recognized genus Pygeum is polyphyletic and that the distinction of the subgenera Padus and Laurocerasus is not supported. The biogeographic interactions of the temperate and tropical members in the Padus/Laurocera- sus/Maddenia alliance including Pygeum are shown to be highly dynamic and complex.  相似文献   

5.
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   

6.
The genus Peperomia is one of the largest genera of basal angiosperms, comprising about 1500-1700 pantropically distributed species. The currently accepted infrageneric classification divides Peperomia into nine subgenera and seven sections. This classification is based on some 200 species, primarily using fruit morphology. The monophyly of these infrageneric taxa has never been tested and molecular phylogenetic studies of a representative sampling within Peperomia do not exist. This paper provides the first molecular phylogeny for the genus Peperomia. Monophyletic clades within Peperomia are identified and previously used morphological characters are critically reviewed. We show that the importance of some morphological characters has been overestimated and that some of these characters presumably have evolved several times independently. Only one previously described subgenus has been confirmed to be monophyletic.  相似文献   

7.
大蚊属Tipula Linnaeus,1758是大蚊科中种类最多的属,目前其单系性尚未得到全面验证.此外,长角大蚊亚属Tipula (Sivatipula) Alexander,1964因其极长的触角以及独有的精子泵结构,明显不同于大蚊属其他亚属,使其亚属的分类地位存在争议.本研究基于COI序列对19个大蚊属物种及5个其他属物种进行了系统发育分析,并计算了物种间的遗传距离.研究结果表明:(1)邻接树(NJ)和最大似然树(ML)均显示长角大蚊亚属与大蚊属其他亚属未形成单系,大蚊属的单系性没有得到支持;(2)基于遗传距离和系统发育分析并结合形态信息,结果显示长角大蚊亚属独立于大蚊属内其他亚属,应将其提升为属级分类单元.  相似文献   

8.
A cladistic study of Anllastrum, Angophora and Eucalyptus (Myrtaceae). Transformed cladistic; character compatibility; branch and bound, and Farris-Wagner methods gave similar solutions in a cladistic study of Arillastrum, Angophora and Eucalyptus. These analyses, based on morphological characters, indicate that Eucalyptus is a monophyletic group and that its sister taxon is Angophora.
Within Eucalyptus , subgenera Blakella and Corymbia are sister taxa to all other groups; subgenera Monocalyptus, Idiogenes and Gaubaea form a monophyletic group with subgenus Monocalyptus sister to subgenera Idiogenes and Gaubaea ; subgenera Symphyomyrtus and Telocalyptus together also form a monophyletic group and, with Eucalyptus similis (subgenus Eudesmia group 4), are sister to the Monocalyptus group. Eucalyptus subgenus Telocalyptus (4 species), Eucalyptus subgenus Idiogenes (1 species) and Eucalyptus subgenus Gaubaea (2 species) should not be recognized as subgenera and some individual species need further examination. Eucalyptus subgenus Eudesmia is a paraphyletic group.
Some characters are identified as parallelisms, e.g. axillary inflorescences, sepaline operculum, bristle glands, and clustered anthers. A more congruent interpretation of the single operculum of Eucalyptus subgenus Monocalyptus as at least partly petaline rather than solely sepaline in origin is suggested.
The area relationships for the taxa are concordant with those derived from geological and climatological information. New Caledonia is sister area to Australia, and within Australia southwestern Australia is sister area to south-eastern and north-eastern Australia.  相似文献   

9.
Among the African Murinae (Rodentia, Muridae), the Praomys complex, whose systematics has been studied by different approaches, has raised numerous taxonomic problems. Different taxa, namely Praomys, Mastomys , Myomys and Hylomyscus have been considered either as separate genera or subgenera of Praomys . In order to understand the relationships within the Praomys complex and to test the monophyly of the genus Praomys , a cladistic analysis was conducted, based on morpho-anatomical factors involving different species of Praomys , Mastomys , Myomys and Hylomyscus. The results indicate that the Praomys complex is monophyletic, as are the genera Hylomyscus , Mastomys and Myomys , whereas the genus Praomys appears paraphyletic. Indeed, a group of species including Praomys jacksoni was found to be more closely related to the genera Mastomys and Myomys than to a Praomys tullbergi -group. The biotopes and the distribution areas of the species were mapped on the phylogeny. It appears that the different clades each present a relative ecological cohesion and are arranged according to a gradient from closed to open habitats. From there, an evolutionary scenario is proposed for the emergence of the different clades and species of the genus Praomys sensu stricto.  相似文献   

10.
11.
Aethomys is a common and widespread rodent genus in the African savannas and grasslands. However, its systematics and taxonomy are still unclear as no study has covered the entire range. In fact it might not be a monophyletic genus and perhaps should be split into two subgenera, Micaelamys and Aethomys. In this paper, we present findings based on the cytogenetics and the entire cytochrome b sequence of two species from Zambia (A. kaiseri) and Tanzania (A. chrysophilus), and we compare them with the sequences of a South African species (A. namaquensis) and other allied muroid genera. Comparison of the banded chromosomes revealed complete G-band homology between the autosomes of the two species. However, the X and Y chromosomes clearly differ in size and in C- and G-banding, being much larger in A. kaiseri. Comparison of the cytochrome b sequences places the separation between A. kaiseri and A. chrysophilus at 4.49 Mya, a period of intense speciation in other African muroids. The resulting phylogeny strongly supports the idea of a paraphyletic group, suggesting the need to elevate the previously described subgenera to the genus rank.  相似文献   

12.
Drosophila species are extensively used in biological research; yet, important phylogenetic relationships within the genus and with related genera remain unresolved. The combined data for three genes (Adh, Sod, and Gpdh) statistically resolves outstanding issues. We define the genus Drosophila inclusively so as to include Scaptomyza and Zaprionus (considered distinct genera in the taxonomy of Wheeler, 1981) but excluding Scaptodrosophila. The genus Drosophila so defined is monophyletic. The subgenus Sophophora (including the melanogaster, obscura, and willistoni groups) is monophyletic and the sister clade to all other Drosophila subgenera. The Hawaiian Drosophila (including Scaptomyza) is a monophyletic group, but the subgenus Drosophila is not monophyletic, because the immigrans group is more closely related to the subgenus Hirtodrosophila than to other species of the subgenus Drosophila, such as the virilis and repleta groups.  相似文献   

13.
The phylogeny of the genus Nassauvia and closely related genera was reconstructed using sequences from the internal transcribed spacer regions (ITS) of nuclear ribosomal DNA. The genus Triptilion is nested within Nassauvia, making the latter genus paraphyletic. Neither of the two subgenera Nassauvia and Strongyloma is resolved as monophyletic, and none of the sections of subgenus Nassauvia is recovered as monophyletic. The evolution of the compound secondary inflorescences has been complex in Nassauvia, with the highly aggregated forms representing the original condition in the genus. However, the ancestral condition is equivocal in several clades, and there are alternative reconstructions for the gains–losses of the variously aggregated conditions. There has been at least one gain of solitary capitula in Nassauvia. The evolution of flavonoid chemistry has been complex in Nassauvia, and flavonoids are of limited phylogenetic-taxonomic utility in the genus. Gains–losses of flavonols occur only on terminals whereas changes in flavones and C-glycosyl flavones occur at various levels in the tree. Gains–losses of methylation of flavones and flavonols occur only on terminals.  相似文献   

14.
The internal transcribed spacer (ITS1, 5.8S rDNA, and ITS2) region of nuclear ribosomal DNA (nrDNA) was sequenced from 53 species, which represent most of the living species diversity in the genus Phalaenopsis (Orchidaceae). A phylogeny was developed for the genus based on the neighbor-joining and maximum parsimony analyses of molecular data. Results of these analyses provided support for the monophyly of the genus Phalaenopsis and concurred in that the genera Doritis and Kingidium should be treated as being parts of the genus Phalaenopsis as suggested by Christenson (2001). Within the genus Phalaenopsis, neither subgenera Aphyllae nor Parishianae were monophyletic, and they were highly clustered with subgenus Proboscidioides plus sections Esmeralda and Deliciosae of subgenus Phalaenopsis based on ITS data. Those species also have the same characters of morphology of four pollinia and similar biogeographies. Furthermore, neither subgenus Phalaenopsis nor Polychilos was monophyletic. Within the subgenus Phalaenopsis, only section Phalaenopsis was highly supported as being monophyletic. As for the subgenus Polychilos, only section Polychilos was moderately supported as being monophyletic. In conclusion, the present molecular data obtained from the ITS sequence of nrDNA of the genus Phalaenopsis provide valuable information for elucidating the phylogeny of this genus.  相似文献   

15.
The apterous genus Timarcha consists of three subgenera and more than 100 species in its Palearctic distribution, with specialized feeding on few plant families. Fifty-four sequences sampled from 31 taxa of the genus plus three outgroup leaf beetles were studied for their complete cytochrome oxidase II (COII) and a fragment of 16S rDNA mitochondrial genes, representing a total of about 1200 bp. Phylogenetic analyses using maximum-parsimony and distance methods for each gene separately and for the combined data set gave compatible topologies. The subgenus Metallotimarcha consistently appears in a basal position and is well differentiated from the remaining Timarcha, but no clear monophyletic grouping of Timarchostoma and Timarcha s. str. subgenera can be deduced from our analysis. Calibration of the molecular clock has been done using the opening of the Gibraltar Strait after the Messinian salinity crisis (about 5.5 MYA) as the biogeographic event causing disjunction of two particular taxa. Accordingly, the COII evolutionary rate has been estimated to be of 0.76 x 10(-8) substitution/site/year in Timarcha. Relation between phylogeny and host-plant use indicates widening of trophic regime as a derived character in Timarcha.  相似文献   

16.
Phylogenetic relationships of the reed warbler group (genera Acrocephalus, Hippolais, Chloropeta; Aves: Passeriformes) and their potential relatives were studied using nucleotide sequences (1 kb) of the mitochondrial cytochrome b gene. This species-rich but morphologically poorly differentiated group of insectivorous passerines is distributed in Eurasia, Africa, and Australasia. Intergeneric relationships were poorly resolved, but monophyly of the reed warbler group (including Chloropeta) versus other Sylviidae was strongly supported. A basal polytomy within the reed warbler group consists of seven branches and may indicate a rapid early radiation. In the genus Acrocephalus three major clades were identified, which corresponded to phenotypic groups characterized by body size and plumage patterns. However, current delimitation of some subgenera (Acrocephalus, Lusciniola, Bebrornis) is at variance with our phylogeny estimate, and appropriate revisions are proposed. The genus Hippolais, which may or may not be monophyletic, consisted of two well-supported clades of four species each. Some Acrocephalus taxa whose species status had been doubted (griseldis, tangorum, orientalis, australis) proved to be highly distinct genetically. Genetic distances between members of two pairs of allopatric Hippolais taxa (caligata/rama; opaca/elaeica) were as large or larger than between other closely related warbler species. Overall, cytochrome b sequences resolved phylogenetically young relationships quite well, whereas more ancient nodes remained poorly resolved.  相似文献   

17.
The hyperdiverse genus Sarcophaga Meigen, with about 890 valid species arranged within 169 subgenera, accounts for almost half of the diversity of the subfamily Sarcophaginae. Current phylogenetic hypotheses for this genus are poorly supported or based on small taxon sets, or both. Here, we use molecular data from the genes COI and 28S to reconstruct the phylogeny of Sarcophaga based on the most comprehensive sampling for the group to date: 144 species from 47 subgenera, including representatives from all regional faunas for the first time. Of the total sequences of Sarcophaga used in the present study, 94.7% were newly generated. The secondary structure of the D1–D3 expansion segments of 28S is presented for the first time for the family Sarcophagidae, and is used in a multiple sequence alignment. Branch support and tree resolution increased remarkably through rogue taxa identification and exclusion. Rogue behaviour was explained mostly as a missing data problem. The RogueNaRok web service and the algorithms chkmoves, IterPCR and prunmajor implemented in the computer program TNT were equally good at identifying critical rogue species, but chkmoves and IterPCR also identified rogue clades. Pruning rogues increased the number of monophyletic subgenera in consensus trees from one to six out of 19 subgenera with more than one representative species. Bayesian inference, maximum‐likelihood and parsimony analyses recovered more monophyletic subgenera after the removal of rogue taxa, with parsimony showing the largest improvements in branch support and resolution. Although with low support, Nearctic taxa were found to be the earliest diverging lineages, followed by a subsequent diversification of Old World faunas, which is in agreement with currently available evidence of a New World origin and early diversification of Sarcophaga.  相似文献   

18.
Marine butterflyfishes (10 genera, 114 species) are conspicuously beautiful and abundant animals found on coral reefs worldwide, and are well studied due to their ecological importance and commercial value. Several phylogenies based on morphological and molecular data exist, yet a well-supported molecular phylogeny at the species level for a wide range of taxa remains to be resolved. Here we present a molecular phylogeny of the butterflyfishes, including representatives of all genera (except Parachaetodon) and at least one representative of all commonly cited subgenera of Chaetodon (except Roa sensuBlum, 1988). Genetic data were collected for 71 ingroup and 13 outgroup taxa, using two nuclear and three mitochondrial genes that total 3332 nucleotides. Bayesian inference, parsimony, and maximum likelihood methods produced a well-supported phylogeny with strong support for a monophyletic Chaetodontidae. The Chaetodon subgenera Exornator and Chaetodon were found to be polyphyletic, and the genus Amphichaetodon was not the basal sister group to the rest of the family as had been previously proposed. Molecular phylogenetic analysis of data from 5 genes resolved some clades in agreement with previous phylogenetic studies, however the topology of relationships among major butterflyfish groups differed significantly from previous hypotheses. The analysis recovered a clade containing Amphichaetodon, Coradion, Chelmonops, Chelmon, Forcipiger, Hemitaurichthys, Johnrandallia, and Heniochus. Prognathodes was resolved as the sister to all Chaetodon, as in previous hypotheses, although the topology of subgeneric clades differed significantly from hypotheses based on morphology. We use the species-level phylogeny for the butterflyfishes to resolve long-standing questions regarding the use of subgenera in Chaetodon, to reconstruct molecular rates and estimated dates of diversification of major butterflyfish clades, and to examine global biogeographic patterns.  相似文献   

19.
Ideally, organisms are grouped into monophyletic assemblages reflecting their evolutionary histories. Single (molecular) markers can reflect the evolutionary history of the marker, rather than the species in question, therefore, phylogenetic relationships should be inferred from adequate sampling of characters. Because the use of multiple loci greatly improves the resolving power of the molecular assay, we constructed a molecular phylogeny of the family Hexagrammidae based on six loci, including two mitochondrial and four nuclear loci. The resulting molecular phylogeny, from the combined data, was significantly different from the morphological topology suggested by Shinohara [Memoirs of the Faculty of Fisheries, Hokkaido University 41 (1994) 1]. Our data support a monophyletic assemblage for the genera Hexagrammos and Pleurogrammus. However, other taxa traditionally included in the family Hexagrammidae did not form a monophyletic assemblage. The monotypic genus Ophiodon was more closely associated with cottids than with other hexagrammids. Our data concur with the morphological topology in that the genera Zaniolepis and Oxylebius formed a monophyletic clade, which was distinct and basal to the remaining hexagrammids, seven cottids and one agonid.  相似文献   

20.
The genus Uroleucon, and the related genus Macrosiphoniella, represent a large Tertiary radiation of aphids, with a total of about 300 species distributed throughout the world, primarily on host plant species in the family Asteraceae. A molecular phylogenetic study was conducted to identify major clades within Uroleucon and to address the cladistic validity of current subgeneric categories, the evolution of host plant associations, the age of origin, and intercontinental movements in this genus. The seventeen study species included members of the three major subgenera of Uroleucon, species from Europe and North America, one member of Macrosiphoniella, and two outgroups. Data consisted of DNA sequences for three mitochondrial regions and the nuclear gene EF1alpha, for a total of 4287 sites. Nodes supported strongly in both parsimony and maximum likelihood analyses suggest that: (1) Nearctic Uromelan are a monophyletic group branching near the base of the genus and not related to European Uromelan, (2) the New World subgenus Lambersius is possibly monophyletic but is not a tightly related group and is not closely related to other North American species, and (3) Nearctic members of subgenus Uroleucon are a closely related monophyletic group not allied with Nearctic Uromelan or Lambersius. Instead they represent a separate colonization by an Old World ancestor, as they are nested within a strongly supported clade containing European members of both subgenera Uroleucon and Uromelan. Neither of these subgenera is monophyletic. Molecular clock calculations, based on calibrations of mitochondrial divergences from other insects, suggest that Uroleucon + Macrosiphoniella is a relatively recent radiation, probably no more than 5–10 million years old. Although largely confined to Asteraceae, this clade did not radiate in parallel with its host plants. Rather, lateral movement between lineages of Asteraceae must have occurred repeatedly.  相似文献   

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