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1.
Less than 1% of Staphylinidae are known to be confined to coastal habitats. To explore the origins of coastal colonization within the tribe Athetini Casey, we present a revised molecular phylogeny. The dataset comprised partial mitochondrial COI, COII, 16S rDNA, NADH1, partial nuclear 18S rDNA and 28S rDNA. We chose a total of 95 species in 51 genera, including 14 coastal species in eight genera and 21 outgroup species from other aleocharine tribes. The concatenated dataset was analysed simultaneously by both parsimony‐ and model‐based (Bayesian and maximum likelihood) methods. The tribe Athetini was not supported as a monophyletic group, but together with the tribes Tachyusini, Ecitocharini and Hygronomini did form a monophylum. The ecological association of species with a coastal habitat was mapped onto a phylogeny to assess the evolution of habitat specialization in the Athetini lineage. The results reveal that five independent origins of coastal colonization have occurred throughout the tribe Athetini: (a) Osakatheta + Adota minuta + coastal Atheta (Badura) (clade A); (b) Adota (clade B); (c) Pontomalota + Tarphiota + Thinusa (clade C); (d) Iotarphia (clade D); and (e) Psammostiba (clade E). The low species number of the coastal Athetini compared with the entire Athetini lineage indicates that coastal habitats are harsh environments and so only a few species were able to colonize this habitat. The following changes in classification are proposed: (a) Ad. minuta Lee and Ahn is removed from the genus Adota and tentatively included in Atheta (Badura); (b) The genus Saphocallus Sharp is transferred from Athetini to Geostibini.  相似文献   

2.
Cryptic species complexes cause major challenges for taxonomists and alter understanding of species diversity. In Northern Europe, the Chrysis ignita species group is one such complex with numerous sympatric sibling species. The objective of this paper is to assess the taxonomy of 15 species from this group using three different approaches: molecular, morphological and trophic differentiation. The analysed set of molecular markers included a 7400‐bp‐long sequence of the mitochondrial genome covering complete sequences of CO1, CO2, ATP8, ATP6, CO3, ND3, 16S and 12S rRNA, nine tRNAs and a partial sequence of CytB, as well as a 3880‐bp‐long sequence of the nuclear DNA covering a part of 18S rRNA, the ITS1, 5.8S rRNA, ITS2 and a part of 28S rRNA. Discrete diagnostic characters of each species sequence were retrieved using the Characteristic Attribute Organisation System algorithm and a molecular identification key was compiled. The study revealed a higher evolutionary rate of the genes ATP8, ATP6, CO3, ND3 and CytB compared to that of CO1, CO2 and 16S; the studied nuclear markers demonstrated a lower evolutionary rate than the mitochondrial markers. A consensus tree compiled based on the combined mtDNA and nuclear markers with a strongly supported topology resolved the position of the C. schencki – C. parietis sp.n. clade as sister to the C. ignita – C. impressa clade and supported the monophyly of the C. angustula – C. longula clade. We compiled a morphometric species identification key applying linear discriminant equations. The trophic differentiation was assessed using data on host preferences of ten Chrysis species reared from trap‐nests; the analysis demonstrated that most of them are specialists exploiting a single or a few taxonomically related host species. In most cases, all three approaches supported the distinct status of the included species. Moreover, two previously undescribed species were consistently supported by the molecular methods. Therefore, we describe these as new, namely C. horridula sp.n. and C. parietis sp.n. Only C. mediata and C. solida were not clearly distinguished using the molecular phylogeny reconstruction methods. However, based on distinctive niche divergence, the presence of molecular characters and morphometric differences, we consider them as phylogenetically young but distinct species. In view of the weak morphological and molecular differentiation, the widely overlapping distribution areas and often similar habitat preferences and the trophic specialization, the C. ignita complex presents a possible model for studies of sympatric cryptic speciation. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:1EBAF0E1‐5FB7‐4CF4‐A595‐C11982448360 .  相似文献   

3.
Erotini is a small tribe of net‐winged beetles known from the northern temperate zone. We investigated relationships and limits of tribes and genera using a molecular phylogeny inferred from rrnL, cox1 and nad5 mtDNA fragments. Lopheros Leconte, 1881 and Pseudaplatopterus Kleine, 1940 were inferred in current molecular analyses as terminal lineages within Erotini. Therefore, we consider Lopherotini Kazantsev, 2012 and Pseudaplatopterina Kazantsev, 2012 as junior synonyms of Erotini Leconte, 1881. The Platycis genus group comprises 19 species representing several genus‐group taxa previously placed in Platycis s. l. Konoplatycis Nakane, 1969 was recovered as a deeply rooted lineage of Erotini and we inferred another independent lineage for which we propose a new genus Sinoplatycis gen. nov. Additionally, we studied the diversity of Platycis s. l. in Asia, found their highest diversity in the temperate forest habitats of Eastern Asia and inferred the paraphyletic character of the subgenus Erotides s. str. Five new species are described from China: Sinoplatycis cardinalis sp. nov. , S. zhani sp. nov. (type species of Sinoplatycis gen. nov. ), Erotides brunnescens sp. nov. , E. pusillus sp. nov. and E. slipinskii sp. nov. The molecular phylogeny shows deep splits of Japanese species with respect to the continental Eurasian fauna and the role of shallow seas and mountain systems in the diversification of the Platycis genus group.  相似文献   

4.
Martínez‐Méndez, N., Mejía, O., Rocha‐Gómez, A. & Méndez‐De La Cruz, F. R. (2012) Morphological convergence and molecular divergence: the taxonomic status of Sceloporus serrifer (squamata, phrynosomatidae) subspecies. —Zoologica Scripta, 41, 97–108. The systematics of the subspecies included in Sceloporus serrifer has undergone several taxonomic and nomenclatural rearrangements. This species previously comprised two recognized subspecies, Sceloporus serrifer serrifer and Sceloporus serrifer prezygus, which inhabit contrasting habitats. In this study, we re‐evaluate the taxonomic status of both subspecies using molecular and morphological evidence. Sceloporus serrifer serrifer was recovered as a paraphyletic group, whereas S. s. prezygus was recovered as a polyphyletic group. The molecular results indicate the existence of two independent lineages that diverged at least 1.29 Myr, with the populations currently recognized as S. s. prezygus from the Cuchumatanes Mountains representing a secondary invasion of S. s. serrifer from the lowlands. The lack of meristic differences among the highland populations of different species suggests convergence in similar environments achieved by two different lineages.  相似文献   

5.
Chalcidoidea (Hymenoptera) is extremely diverse with an estimated 500 000 species. We present the first phylogenetic analysis of the superfamily based on both morphological and molecular data. A web‐based, systematics workbench mx was used to score 945 character states illustrated by 648 figures for 233 morphological characters for a total of 66 645 observations for 300 taxa. The matrix covers 22 chalcidoid families recognized herein and includes 268 genera within 78 of 83 subfamilies. Morphological data were analysed alone and in combination with molecular data from ribosomal 18S (2105 bp) and 28S D2–D5 expansion regions (1812 bp). Analyses were analysed alone and in combined datasets using implied‐weights parsimony and likelihood. Proposed changes in higher classification resulting from the analyses include: (i) recognition of Eriaporidae, revised status; (ii) recognition of Cynipencyrtidae, revised status; (iii) recognition of Azotidae, revised status; (iv) inclusion of Sycophaginae in Agaonidae, revised status; (v) reclassification of Aphelinidae to include Aphelininae, Calesinae, Coccophaginae, Eretmocerinae and Eriaphytinae; (vi) inclusion of Cratominae and Panstenoninae within Pteromalinae (Pteromalidae), new synonymy; (vii) inclusion of Epichrysomallinae in Pteromalidae, revised status. At a higher level, Chalcidoidea was monophyletic, with Mymaridae the sister group of Rotoitidae plus the remaining Chalcidoidea. A eulophid lineage was recovered that included Aphelinidae, Azotidae, Eulophidae, Signiphoridae, Tetracampidae and Trichogrammatidae. Eucharitidae and Perilampidae were monophyletic if Eutrichosomatinae (Pteromalidae) was included, and Eupelmidae was monophyletic if Oodera (Pteromalidae: Cleonyminae) was included. Likelihood recovered a clade of Eupelmidae + (Tanaostigmatidae + (Cynipencyrtus + Encyrtidae). Support for other lineages and their impact on the classification of Chalcidoidea is discussed. Several life‐history traits are mapped onto the new phylogeny.  相似文献   

6.
We performed a phylogenetic analysis using nuclear (RAG‐1, RAG‐2) and mitochondrial (16S) markers, a statistical Bayesian reconstruction of ancestral distribution areas and a karyological analysis on most Malagasy species of the gekkonid genus Lygodactylus. The phylogenetic analysis largely confirms major basal branching pattern of previous molecular studies, but highlights significant differences concerning both the relationships between different species groups as well as those within groups. The biogeographic analysis supports a Malagasy origin of Lygodactylus, an oversea dispersal to continental Africa and a return to Madagascar. The L. madagascariensis group (also including a new candidate species identified herein) is the most basal clade in Lygodactylus, and the sister group of a clade with all the remaining species. The second most basal clade is the L. verticillatus group, placed as the sister group of a clade comprising African and Malagasy species. The sister lineage of the L. verticillatus group originated the African radiation through an oversea dispersal out of Madagascar. Eventually, the sister lineage of the L. capensis group originated secondary dispersals from Africa to Madagascar. In Madagascar, lineage diversification in different species groups mainly occurred from southern to northern and eastern regions. Dispersal, vicariance and paleoclimatic refugia probably played a relevant role in the evolutionary history of closely related taxa and in speciation mechanisms. The cytogenetic analysis evidenced a high karyotypic variability in Lygodactylus (from 2n = 34 to 2n = 40), which is at least partly consistent with the phylogenetic relationships and the composition of the various species group. Chromosome evolution occurred independently in different lineages, mainly through a reduction in the chromosome number and starting from a putative primitive karyotype of 2n = 40 with all telocentric elements.  相似文献   

7.
The defatted fractions of the Faramea hyacinthina and Ftruncata (Rubiaceae) leaf MeOH extracts showed in vitro non‐cytotoxic and anti‐dengue virus serotype 2 (DENV2) activity in human hepatocarcinoma cell lineage (HepG2). Submitting these fractions to the developed RP‐SPE method allowed isolating the antiviral flavanone (2S)‐isosakuranetin‐7‐Oβ‐d ‐apiofuranosyl‐(1→6)‐β‐d ‐glucopyranoside ( 1 ) from both species and yielded less active sub‐fractions. The new diastereoisomeric epimer pair (2S) + (2R) of 5,3′,5′‐trihydroxyflavanone‐7‐Oβ‐d ‐apiofuranosyl‐(1→6)‐β‐d ‐glucopyranoside ( 2a / 2b ) from Fhyacinthina; the known narigenin‐7‐Oβ‐d ‐apiofuranosyl‐(1→6)‐β‐d ‐glucopyranoside ( 3 ) from both species; rutin ( 4 ) and quercetin‐4′‐β‐d ‐O‐glucopyranosyl‐3‐O‐rutinoside ( 5 ) from Fhyacinthina, and kaempferol‐3‐O‐rutinoside ( 6 ), erythroxyloside A ( 7 ) and asperuloside ( 8 ) from Ftruncata have been isolated from these sub‐fractions. Compounds 4  –  8 are reported for the first time in Faramea spp.  相似文献   

8.
We examined the hypothesis that genotypic variation among populations of commonly co‐occurring phreatophytic trees (Populus fremontii, Salix gooddingii) and the shrub (Salix exigua) regulates aboveground net primary productivity (ANPP) at a hot site at the edge of the species’ distribution. We used a provenance trial in which replicated genotypes from populations varying in mean annual temperature were transplanted to a common garden adjacent to the Lower Colorado River in southeastern California. The garden environment represented an extreme maximum temperature for the study species. Four major findings emerged: (1) Genotypic variation in ANPP was significant for all species with broad‐sense heritability (H2) across populations of 0.11, 0.13, and 0.10 for P. fremontii, S. gooddingii, and S. exigua, respectively, and within‐population H2 ranging from 0.00 to 0.25, 0.00 to 0.44, and 0.02 to 0.21, respectively. (2) Population ANPP decreased linearly as mean annual maximum temperature (MAMT) transfer distance increased for both P. fremontii (r2 = 0.64) and S. gooddingii (r2 = 0.37), whereas it did not change for S. exigua; (3) Populations with similar MAMT to that of the common garden were 1.5 and 1.2 times more productive than populations with 5.0 °C MAMT transfer distances for P. fremontii and S. gooddingii, respectively; and (4) Variation in regression slopes among species for the relationship between ANPP and MAMT indicate species‐specific responses to temperature. As these plant species characterize a threatened habitat type and support a diverse community that includes endangered species, ecosystem restoration programs should consider using both local genotypes and productive genotypes from warmer environments to maximize productivity of riparian ecosystems in the face of global climate change.  相似文献   

9.
The subfamily Crucigenioideae was traditionally classified within the well‐characterized family Scenedesmaceae (Chlorophyceae). Several morpho‐logical revisions and questionable taxonomic changes hampered the correct classification of crucigenoid species resulting in a high number of synonymous genera. We used a molecular approach to determine the phylogenetic position of several Tetrastrum and Crucigenia species. The molecular results were correlated with morphological and ontogenetic characters. Phylogenetic analyses of the SSU rDNA gene resolved the position of Tetrastrum heteracanthum and T. staurogeniaeforme as a new lineage within the Oocystis clade of the Trebouxiophyceae. Crucigenia tetrapedia, T. triangulare, T. punctatum, and T. komarekii were shown to be closely related to Botryococcus (Trebouxiophyceae) and were transferred to Lemmer‐mannia. Crucigenia lauterbornii was not closely related to the other Crucigenia strains, but was recovered within the Chlorella clade of the Trebouxiophyceae.  相似文献   

10.
The phylogeny of the subfamily Ophioninae (Hymenoptera: Ichneumonidae) is investigated using molecular markers and morphological characters. We analysed the mitochondrial DNA CO1 and the nuclear 28S D2–D3 gene fragments for 74 species of Ophioninae from 25 out of the 32 recognized genera, which collectively represent 98% of described species diversity of the subfamily. Molecular markers were analysed separately and combined, with or without the adjunction of a matrix of 62 morphological characters using Bayesian inference. Our results reveal three distinct lineages, each including one of most speciose genera: Ophion, Enicospilus and Thyreodon. The comparison of the molecular data, and combined molecular plus morphological data led to the definition of the three tribes: Ophionini stat. rev. (Ophion Alophophion Rhopalophion Xylophion Afrophion); Enicospilini stat. rev. (Enicospilus Laticoleus Dicamptus Hellwigiella); and Thyreodonini tribe nov. (Thyreodon Dictyonotus Rhynchophion). The possible association of other genera to one or another of these lineages is discussed. Ophion is a polyphyletic assemblage and requires a further revision to define the delimitation with close genera. The enigmatic Old World genus Skiapus is strongly supported as belonging to the Ophioninae, although its placement within the subfamily is ambiguous as a result of its derived genotype and phenotype. Finally, we propose a biogeographical scenario supported by this phylogeny and based on the limited available fossil data.  相似文献   

11.
Surprisingly, little is known about the extent of genetic structure within widely distributed and polytypic African species that are not restricted to a particular habitat type. The few studies that have been conducted suggested that speciation among African vertebrates may be intrinsically tied to habitat and the dynamic nature of biome boundaries. In the present study, we assessed the geographic structure of genetic variation across two sister‐species of drongos, the Square‐tailed Drongo (Dicrurus ludwigii) and the Shining Drongo (D. atripennis), that are distributed across multiple sub‐Saharan biogeographic regions and habitat types. Our results indicate that D. ludwigii consists of two strongly divergent lineages, corresponding to an eastern–southern lineage and a central‐western lineage. Furthermore, the central‐western lineage may be more closely related to D. atripennis, a species restricted to the Guineo‐Congolian forest block, and it should therefore be ranked as a separate species from the eastern–southern lineage. Genetic structure is also recovered within the three primary lineages of the D. atripennisD. ludwigii complex, suggesting that the true species diversity still remains underestimated. Additional sampling and data are required to resolve the taxonomic status of several further populations. Overall, our results suggest the occurrence of complex diversification patterns across habitat types and biogeographic regions in sub‐Saharan Africa birds.  相似文献   

12.
We investigated the species trees, temporal divergence and historical biogeography of Emplenota Casey and Triochara Bernhauer (ET clade hereafter), subgenera of the Aleochara coastal staphylinid beetles, to determine their place of origin. We explored a multilocus dataset to infer gene trees and species trees based on traditional concatenated and multispecies coalescent‐based approaches using both model‐ (maximum likelihood and Bayesian) and parsimony‐based methods. The multilocus dataset comprised DNA sequences from five nuclear genes (ArgK, CAD, EF1‐α, wg and 28S) and three mitochondrial genes (COI, COII and 16S). *BEAST analysis according to a coalescent‐based approach resolved the following phylogenetic relationships: ((Atrisulcata (Anubis Azerchei)) (Aobscurella ((Apacifica (Acurtidens + A. litoralis)) (Ahayamai (Ayamato (Afucicola (Asegregata Apuetzi))))))). Using a relaxed molecular clock, we reconstructed a time‐calibrated phylogeny for this group. Furthermore, to account for the historical biogeography of the ET clade at the ages of major divergences, we investigated the ancestral area based on a time‐calibrated phylogeny. Biogeographical analyses suggested that the ancestor of the ET clade was widely distributed along the eastern and western Palearctic and the western Nearctic coasts in the early Miocene. According to reconstruction of the ancestral area, one dispersal and three vicariance events were required, and the analyses indicated that vicariance events were important in shaping its current distribution patterns. Most of the divergence events occurred in the late Miocene and early Pliocene along the Pacific coasts, and the East Asian seacoasts harboured the most species‐rich fauna, including eight of the 13 species in the ET clade.  相似文献   

13.
The first large‐scale, total‐evidence phylogeny of the owlflies (Neuroptera, Ascalaphidae) is presented. A combined morphological and molecular dataset was analysed under several analytical regimes for 76 exemplars of Myrmeleontiformia (Psychopsidae, Nymphidae, Nemopteridae, Myrmeleontidae, Ascalaphidae), including 57 of Ascalaphidae. At the subordinal level, the families were recovered in all analyses in the form Psychopsidae + (Nymphidae + (Nemopteridae + (Myrmeleontidae + Ascalaphidae). In the DNA‐only maximum‐likelihood analysis, Ascalaphidae were recovered as paraphyletic with respect to the Myrmeleontidae and the tribe Ululodini. In both the parsimony and Bayesian total‐evidence analyses, however, the latter with strong support, traditional Ascalaphidae were recovered as monophyletic, and in the latter, Stilbopteryginae were placed as the immediate sister group. The long‐standing subfamilies Haplogleniinae and Ascalaphinae were not recovered as monophyletic in any analysis, nor were several of the included tribes of non‐ululodine Ascalaphinae. The Ululodini were monophyletic and well supported in all analyses, as were the New World Haplogleniinae and, separately, the African/Malagasy Haplogleniinae. The remaining Ascalaphidae, collectively, were also consistently cohesive, but included a genus that until now has been placed in the Haplogleniinae, Protidricerus. Protidricerus was discovered to express a well‐developed pleurostoma, a feature previously only encountered in divided‐eye owlflies. The feature traditionally used to differentiate the Haplogleniinae and Ascalaphinae, the entire or divided eye, can no longer be regarded as a spot‐diagnostic synapomorphy to separate these groups within the family. A new subfamilial classification based on these results is proposed and includes the following five subfamilies: Albardiinae, Ululodinae, Haplogleniinae, Melambrotinae and Ascalaphinae. In addition, the monophyletic containing group (Myrmeleontidae + (Palparidae + (Stilbopterygidae + Ascalaphidae))) is elevated to the rank of superfamily, as Myrmeleontoidea, in order to accommodate much‐needed taxonomic and nomenclatural restructuring anticipated to occur within the Ascalaphidae in the future. A list of genera included in each subfamily of Ascalaphidae is provided.  相似文献   

14.
The genus Copidosoma (Hymenoptera: Chalcidoidea: Encyrtidae) is a diverse group of polyembryonic parasitoids of Lepidoptera, including species that have the potential to control agricultural and forestry pests. Moreover, some species of Copidosoma display polyembryony. Despite their economic and scientific importance, little is known about the phylogeny of Copidosoma and its relations to other groups of Encyrtidae. Here we infer the phylogenetic relationships of this genus from nucleotide sequences of two nuclear (18S and 28S) and one mitochondrial (COI) genes. Forty‐four species of Copidosoma and three species of Copidosomopsis plus two outgroup species are included in Maximum Parsimony and Bayesian analyses. Copidosomopsis syn. n . is proposed as a junior synonym of Copidosoma based on phylogenetic analysis results. Each of nine identical clades, resulting from both analyses, is proposed as informal species group: cervius group (cervius, chalconotum and serricorne), recovered as the basal lineage of Copidosoma; nacoleiae group (nacoleaie, meridionalis and an undescribed species, formerly belonging to the genus Copidosomopsis); boucheanum group (boucheanum, terebrator, peticus, phaloniae, ancharus, tibiale and sosares); noyesi group (noyesi and probably undescribed related species); albipes group (albipes and coimbatorense); varicorne group (including varicorne and subalbicorne in one subclade, and aretas and fuscisquama in the other); thebe group (thebe and probably undescribed related species); exiguum group (exiguum and probably undescribed related species); floridanum group (floridanum, primulum, transversum, truncatellum and agrotis). Host associations of the genus and host specificity of recognized groups are discussed. The current work offers a foundation for a comprehensive phylogeny of Copidosoma and the possibility to reconstruct cophylogeny between Copidosoma and their lepidopteran hosts.  相似文献   

15.
In order to place a newly discovered species Antigracilus costatus gen. sp. n. from the Lower Cretaceous Yixian Formation (China) and to assess previously unplaced fossil taxa, we investigated the relationships of extant and extinct lineages of Histeridae based on three data sets: (i) 69 morphological characters belonging to 48 taxa (representing all 11 subfamilies and 15 of 17 tribes of modern Histeridae); (ii) partitioned alignment of 6030 bp from downloaded nucleotide sequences (28S, CAD, COI, 18S) of 50 taxa (representing 10 subfamilies and 15 of 17 tribes of modern Histeridae); and (iii) a combined morphological and molecular dataset for 75 taxa. Phylogenetic analyses of the morphology and combined matrices recovered the new Lower Cretaceous taxon as a sister group to remaining Histeridae and it is placed in †Antigracilinae subfam. n. †Antigracilinae constitutes the earliest record of Histeridae from the Lower Cretaceous Yixian Formation (∼125 Myr), backdating the minimum age of the family by 25 Myr from the earliest Cenomanian (~99 Myr) to the Barremian of the Cretaceous Period. Our molecular phylogeny supports Histeridae to be divided into seven different clades, with currently recognised subfamilies Abraeinae (sensu lato), Saprininae, Chlamydopsinae, and Histerinae (sensu lato) recovered as monophyletic, while Dendrophilinae, Onthophilinae, and Tribalinae are polyphyletic taxa. The Burmese amber species †Pantostictus burmanicus Poinar & Brown is placed as a sister group to the tribe Plegaderini (Abraeinae) and was assigned as a new tribe Pantostictini trib. n. Both molecular and combined phylogenies recovered the subfamilies Trypanaeinae and Trypeticinae deeply within the subfamily Abraeinae (sensu lato), and they are downgraded into Trypanaeini stat. n. and Trypeticini stat. n.  相似文献   

16.
The frog clade composed of the alsodid genera Alsodes + Eupsophus is the most species‐rich of the Patagonian endemic frog clades, including nearly 31 of the slightly more than 50 species of that region. The biology of this group of frogs is poorly known, its taxonomy quite complex (particularly Alsodes), and its diversity in chromosome number striking when compared with other frogs (collectively, there are species having 2n = 22, 2n = 26, 2n = 28, 2n = 30 or 2n = 34). We present a phylogenetic analysis of this Patagonian frog clade based on mitochondrial and nuclear gene sequences. We sequenced five mitochondrial genes (cytochrome b, cytochrome oxidase I, 12S, 16S, NADH dehydrogenase subunit 1) with three intervening tRNAs, and fragments of three nuclear genes (seven in absentia homolog 1, rhodopsin exon 1, RAG‐1), for a maximum of 6510 bp for multiple specimens from 26 of the 31 species. We recovered Eupsophus as polyphyletic, with E. antartandicus, E. sylvaticus, and E. taeniatus in Batrachylidae, in accordance with most previous hypotheses. Based on this result, we transfer E. antartandicus and E. taeniatus back to Batrachyla, and E. sylvaticus to Hylorina (resurrected from the synonymy of Eupsophus), remediating the paraphyly of Eupsophus. Our results strongly corroborate the monophyly of Alsodes + Eupsophus (sensu stricto), the individual monophyly of these genera, and the monophyly of the species groups of Eupsophus. They also show the non‐monophyly of all non‐monotypic species groups of Alsodes proposed in the past. Our results expose several taxonomic problems particularly in Alsodes, and to a lesser extent in Eupsophus. This phylogenetic context suggests a rich evolutionary history of karyotypic diversification in the clade, in part corroborating previous hypotheses. In Alsodes, we predict three independent transformations of chromosome number from the plesiomorphic 2n = 26. All these, strikingly, involve increments or reductions of pairs of haploid chromosomes. Finally, the phylogenetic pattern recovered for Alsodes and Eupsophus suggests a trans‐Andean origin and diversification of the group, with multiple, independent ingressions over cis‐Andean regions.  相似文献   

17.
The phylogenetic position of Cephalenchus is enigmatic with respect to other tylench nematodes. In this study, Cephalenchus populations representing 11 nominal species were sampled worldwide for molecular and morphological characterization. Species identification was based on light microscopy (LM) and scanning electron microscopy (SEM). Molecular analyses were based on the genes (i.e. 18S, 28S, 5.8S) and internal transcribed spacers (ITS‐1 and ITS‐2) of the ribosomal RNA (rRNA). Phylogenetic analyses (i.e. full and reduced alignments) of either concatenated or single genes always supported the monophyly of Cephalenchus. A sister relationship between Cephalenchus and Eutylenchus excretorius was recovered by most analyses, although branch support varies depending on the dataset used. The position of Cephalenchus + E. excretorius within Tylenchomorpha nevertheless remains ambiguous, thus highlighting the importance of sampling additional genes as well as taxa. Placement of Cephalenchus + E. excretorius as sister of Tylenchinae or Boleodorinae could not be rejected on the basis of 18S and 28S rRNA genes. Within Cephalenchus, amphidial opening morphology shows congruence with molecular‐based phylogenetic relationships, whereas the number of lines in the lateral field is likely to be a convergent trait. Morphometric analyses clearly distinguished short tail from medium–long tail species, and SEM observations seem to suggest a relation between tail length and amphidial opening. In addition, molecular phylogenies support the non‐monophyly of Cephalenchus cephalodiscus, Cephalenchus cylindricus, Cephalenchus daisuce and Cephalenchus leptus. The known extent of Cephalenchus diversity is increased with the inclusion of two new species, and the biogeography of the genus is discussed.  相似文献   

18.
19.
20.
Species delimitation through which infers species boundaries is emerging as a major work in modern systematics. Hop‐hornbeam species in Ostrya (Betulaceae) are well known for their hard and heavy woods. Five species were described in China and their interspecific delimitations remain unclear. In this study, we firstly explored their distributions in all recorded field sites distributed in China. We then selected 110 samples from 22 natural populations of five species from this genus and one type specimen of O. yunnanensis, for molecular barcoding analyses. We sequenced four chloroplast (cp) DNA fragments (trnH–psbA, trnL–trnF, rps16, and trnG) and the nuclear internal transcribed spacer (ITS) region for all samples. Sequence variations of Ostrya from four cpDNA fragments identified three groups that showed no correspondence to any morphological delimitation because of the incomplete lineage sorting and/or possible interspecific introgression in the history. However, phylogenetic analyses of ITS sequence variations discerned four species, O. japonica, O. rehderiana, O. trichocarpa, and O. multinervis while O. yunnanensis nested within O. multinervis. Morphological clustering also discerned four species and showed the complete consistency with molecular evidence. Moreover, our phylogenetic analyses‐based ITS sequence variations suggested that O. trichocarpa comprised an isolated lineage different from the other Eurasian ones. Based on these results, hop‐hornbeams in China should be treated as four separate species. Our results further highlight the importance of ITS sequence variations in delimitating and discerning the closely related species in plants.  相似文献   

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