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1.
A restriction-site analysis of chloroplast DNA from 44 species, representing 19 genera and all six subfamilies of the Crassulaceae was conducted using 12 restriction endonucleases. A total of 969 variable sites was detected, 608 of which were phylogenetically informative and used in parsimony analysis. Estimated values of nucleotide sequence divergence were used to construct a distance tree by the neighbor-joining method. Maximum sequence divergence in the family was ~7%. Different tree inference methods yielded only moderately different topologies. The amount of support for the monophyletic groups obtained in the Wagner parsimony analysis was evaluated by bootstrap and decay analysis. There is very strong support for a basal division of the family, which separates the monophyletic subfamily Crassuloideae from all other taxa. Four of the six traditionally recognized subfamilies are indicated to be polyphyletic. These include the Cotyledonoideae, Sempervivoideae, Sedoideae, and Echeverioideae. The Kalanchoideae and the genera Cotyledon and Adromischus exhibit low levels of cpDNA sequence divergence relative to one another, suggesting a relatively recent radiation. The genera Sedum and Rosularia are indicated to be polyphyletic. Sedum comprises sister taxa of most of the other genera of the family.  相似文献   

2.
Parmeliaceae is the largest family of lichen-forming fungi with more than 2000 species and includes taxa with different growth forms. Morphology was widely employed to distinguish groups within this large, cosmopolitan family. In this study we test these morphology-based groupings using DNA sequence data from three nuclear and one mitochondrial marker from 120 taxa that include 59 genera and represent the morphological and chemical diversity in this lineage. Parmeliaceae is strongly supported as monophyletic and six well-supported main clades can be distinguished within the family. The relationships among them remain unresolved. The clades largely agree with the morphology-based groupings and only the placement of four of the genera studied is rejected by molecular data, while four other genera belong to clades previously unrecognised. The classification of these previously misplaced genera, however, has already been questioned by some authors based on morphological evidence. These results support morphological characters as important for the identification of monophyletic clades within Parmeliaceae.  相似文献   

3.
Notoriously slow rates of molecular evolution and convergent evolution among some morphological characters have limited phylogenetic resolution for the palm family (Arecaceae). This study adds nuclear DNA (18S SSU rRNA) and chloroplast DNA (cpDNA; atpB and rbcL) sequence data for 65 genera of palms and characterizes molecular variation for each molecule. Phylogenetic relationships were estimated with maximum likelihood and maximum parsimony techniques for the new data and for previously published molecular data for 45 palm genera. Maximum parsimony analysis was also used to compare molecular and morphological data for 33 palm genera. Incongruence among datasets was detected between cpDNA and 18S data and between molecular and morphological data. Most conflict between nuclear and cpDNA data was associated with the genus Nypa. Several taxa showed relatively long branches with 18S data, but phylogenetic resolution of these taxa was essentially the same for 18S and cpDNA data. Base composition bias for 18S that contributed to erroneous phylogenetic resolution in other taxa did not seem to be present in Palmae. Morphological data were incongruent with all molecular data due to apparent morphological homoplasy for Caryoteae, Ceroxyloideae, Iriarteae, and Thrinacinae. Both cpDNA and nuclear 18S data firmly resolved Caryoteae with Borasseae of Coryphoideae, suggesting that at least some morphological characters used to place Caryoteae in Arecoideae are homoplastic. In this study, increased character sampling seems to be more important than increased taxon sampling; a comparison of the full (65-taxon) and reduced (45- and 33-taxon) datasets suggests little difference in core topology but considerably more nodal support with the increased character sample sizes. These results indicate a general trend toward a stable estimate of phylogenetic relationships for the Palmae. Although the 33-taxon topologies are even better resolved, they lack several critical taxa and are affected by incongruence between molecular and morphological data. As such, a comparison of results from the 45- and 33-taxon trees offers the best available reference for phylogenetic inference on palms.  相似文献   

4.
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   

5.
The resolution of the phylogenetic relationships within the order Teloschistales (Ascomycota, lichen-forming-fungi), with nearly 2000 known species and outstanding phenotypic diversity, has been hindered by the limitation in the resolving power that single-locus or two-locus phylogenetic studies have provided to date. In this context, an extensive taxon sampling within the Teloschistales with more loci (especially nuclear protein-coding genes) was needed to confront the current taxonomic delimitations and to understand evolutionary trends within this order. Comprehensive maximum likelihood and bayesian analyses were performed based on seven loci using a cumulative supermatrix approach, including protein-coding genes RPB1 and RPB2 in addition to nuclear and mitochondrial ribosomal RNA-coding genes. We included 167 taxa representing 12 of the 15 genera recognized within the currently accepted Teloschistineae, 22 of the 43 genera within the Physciineae, 49 genera of the closely related orders Lecanorales, Lecideales, and Peltigerales, and the dubiously placed family Brigantiaeaceae and genus Sipmaniella. Although the progressive addition of taxa (cumulative supermatrix approach) with increasing amounts of missing data did not dramatically affect the loss of support and resolution, the monophyly of the Teloschistales in the current sense was inconsistent, depending on the loci-taxa combination analyzed. Therefore, we propose a new, but provisional, classification for the re-circumscribed orders Caliciales and Teloschistales (previously referred to as Physciineae and Teloschistineae, respectively). We report here that the family Brigantiaeaceae, previously regarded as incertae sedis within the subclass Lecanoromycetidae, and Sipmaniella, are members of the Teloschistales in a strict sense. Within this order, one lineage led to the diversification of the mostly epiphytic crustose Brigantiaeaceae and Letrouitiaceae, with a circumpacific center of diversity and found mostly in the tropics. The other main lineage led to another epiphytic crustose family, mostly tropical, and with an Australasian center of diversity--the Megalosporaceae--which is sister to the mainly rock-inhabiting, cosmopolitan, and species rich Teloschistaceae, with a diversity of growth habits ranging from crustose to fruticose. Our results confirm the use of a cumulative supermatrix approach as a viable method to generate comprehensive phylogenies summarizing relationships of taxa with multi-locus to single locus data.  相似文献   

6.
Abstract Leptophlebiidae is among the largest and most diverse groups of extant mayflies (Ephemeroptera), but little is known of family‐level phylogenetic relationships. Using two nuclear genes (the D2 + D3 region of 28S ribosomal DNA and histone H3) and maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference (BI), we inferred the evolutionary relationships of 69 leptophlebiids sampled from six continents and representing 30 genera plus 11 taxa of uncertain taxonomic rank from Madagascar and Papua New Guinea. Although we did not recover monophyly of the Leptophlebiidae, monophyly of two of the three leptophlebiid subfamilies, Habrophlebiinae and Leptophlebiinae, was recovered with moderate to strong support in most analyses. The Atalophlebiinae was rendered paraphyletic as a result of the inclusion of members of Ephemerellidae or the Leptophlebiinae clade. For the species‐rich Atalophlebiinae, four groups of taxa were recovered with moderate to strong branch support: (i) an endemic Malagasy clade, (ii) a Paleoaustral group, a pan‐continental cluster with members drawn from across the southern hemisphere, (iii) a group, uniting fauna from North America, southeast Asia and Madagascar, which we call the Choroterpes group and (iv) a group uniting three New World genera, Thraulodes, Farrodes and Traverella. Knowledge of the phylogenetic relationships of the leptophlebiids will aid in future studies of morphological evolution and biogeographical patterns in this highly diverse and speciose family of mayflies.  相似文献   

7.
Summary Gel electrophoretic investigations were made on the seed albumins of several members of the family Papilionaceae. Relationships were found with taxa of a lower order i.e. between mutants, varieties and subspecies. More distantly related ones, for example species of the same genus or species of different genera, did not show similarities. Thus, it was concluded that the albumin banding pattern is only suitable for studying phylogenetic and taxonomic problems if the material under investigation is not too distantly related.  相似文献   

8.
Sequences from the mitochondrial cytochrome oxidase subunit 2 gene (cox2) were determined for 14 species from the family Ceratopogonidae, representing 12 genera and all five subfamilies, along with six representatives of other nematoceran families. The purpose was to develop a molecular phylogeny of the Ceratopogonidae, and interpret the phylogenetic position of the family within the infraorder Culicomorpha. These taxa have been analysed using cladistic methodology which, in combination with an excellent fossil record, provides a well established morphological phylogeny. Sequence analysis of cox2 revealed a high degree of sequence divergence among the species, reflecting in part the antiquity of the family, but also a significant acceleration of sequence evolution in the ceratopogonids compared to other nematoceran Diptera. Phylogenetic reconstruction by neighbor-joining and maximum parsimony gave strong support for an early separation of an ancient lineage that includes the two genera, Austroconops and Leptoconops, from the remainder of the family. The results support the existence of a clade that includes two subfamilies, Dasyheleinae and Forcipomyiinae, and this clade appears as sister to the remaining subfamily, Ceratopogoninae. The molecular phylogeny also supports monophyly of the Ceratopogonidae, and either a sister or paraphyletic relationship of this family with the Chironomidae.  相似文献   

9.
The family Baetidae, which belongs to the order Ephemeroptera, was first described by Leach in 1815 . Since then, almost 100 genera and 900 species have been described. Although diverse, this family is relatively homogeneous. The adults are extremely similar to one another, the wings vary little and the penes are membranous, features that significantly reduce differentiation among taxa. In contrast, the larvae have more conspicuous differences. Most are collector–gatherers, but a few are carnivorous or filter feeders. In South America, although knowledge concerning the 27 genera and 132 species of Baetidae described for this region has improved in the last three decades, phylogenetic relationships remain unknown. The present study, the first cladistic analysis of Baetidae in South America, included 70 species (55 are Neotropical) and 126 morphological characters. The matrix was analysed using tnt , under implied weights. Although the monophyly of the family Baetidae was obtained with good support, the subfamilies proposed originally (Baetinae, Cloeoninae and Callibaetinae) were recovered as paraphyletic. The Baetodes complex, as well as the relationships between genera, is discussed. The validity of some structures or characters as support of different groupings is also discussed.  相似文献   

10.
The sequence data from the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase ( rbc L) gene and 18S ribosomal DNA (small subunit) of taxa in the freshwater rhodophyte order Batrachospermales were used to construct phylogenetic hypotheses. Taxa examined in this study represent four families, eight genera, and six sections of the genus Batrachospermum . In addition, Rhododraparnaldia oregonica Sheath, Whittick et Cole, was included in the analysis because it shares particular ultrastructural, reproductive, and morphological characteristics with members of the Batrachospermales and Acrochaetiales. The trees generated from each gene, as well as a combined data set, were largely congruent. Rhododraparnaldia consistently occurs on an early branch within the Acrochaetiales – Palmariales clade and does not appear to be a member of the Batrachospermales. In addition, Thorea violacea Bory de St. Vincent was not closely related to the other taxa of the Batrachospermales in all trees and hence the family Thoreaceae does not appear to be a natural grouping within this order. All other taxa analyzed, which are presently classified within this order, formed a monophyletic clade in most analyses. Psilosiphon scoparium Entwisle was not closely allied with the taxa of the Lemaneaceae, lending support to the newly proposed family Psilosiphonaceae. Sequence data from the remaining taxa of the Lemaneaceae support the concept of a derived monophyletic clade. The genus Batrachospermum appears to comprise many morphologically similar but distantly related taxa, which will need further investigation to resolve their taxonomic status. Tuomeya, Sirodotia and Nothocladus are retained at the generic level until further data are obtained.  相似文献   

11.
詹玲  于晶  郭水良 《植物学报》2017,52(2):241-253
木灵藓科(Orthotrichaceae)是藓类植物中的第3大科。该科不仅种类多, 生态类型特殊, 而且是世界公认的多样化程度高、分类难度大、系统关系复杂的类群。当代木灵藓科植物分类系统学研究主要集中在该科的地区志编写和专属分类修订。目前, 除了热带美洲、热带非洲的变齿藓属(Zygodon)和火藓属(Schlotheimia)部分类群外, 木灵藓科主要类群的分类修订工作已基本完成, 但是有关亚科和属的划分和地位以及各属之间的关系等方面仍存在众多争议。木灵藓科分支系统学研究也不够系统全面, 有的仅应用了单个基因片段, 或者只涉及少数类群。因此, 需要基于更多的分子和形态学性状, 进一步开展世界木灵藓科植物的系统发育研究, 建立一个更趋自然的木灵藓科分类系统。  相似文献   

12.
The phylogenetic relationships among characids are complex with many genera remaining of uncertain systematic position inside the family. The genus Hollandichthys is one of these problematic genera. It has been considered as incertae sedis inside this family until two recently published phylogenies, one morphological and one molecular, arrived at alternative hypothesizes as to the relationships of Hollandichthys with Pseudochalceus or Rachoviscus, respectively. In this paper, we infer the phylogenetic relations of these taxa based on five genes (three mitochondrial - COI, ND2 and 16S; and two nuclear - Sia and Trop), totaling up to 2719 bp. The 41 analyzed species in the Characidae include four incertae sedis characid taxa once hypothesized as related to Hollandichthys, but never analyzed in a single phylogeny (Rachoviscus, Pseudochalceus, Nematocharax and Hyphessobrycon uruguayensis). Here we propose Rachoviscus as the sister-group of Hollandichthys, grouped in the large clade C previously defined, along with the remaining incertae sedis taxa studied here. In addition, we support the evidence that insemination evolved independently at least three times in the Characidae.  相似文献   

13.
Phylogenies inferred from the analysis of DNA sequence data have shown that the Onygenales contains clades that do not correspond with previously described families. One lineage identified in recent molecular phylogenetic studies includes the dimorphic pathogens belonging to the genera Ajellomyces, Emmonsia and Paracoccidioides. To evaluate the degree of support for this lineage and determine whether it includes additional taxa, we examined relationships among the members of this clade and selected saprobic onygenalean taxa based on maximum-parsimony analyses of partial nuclear large RNA subunit (LSU) and internal transcribed spacer (ITS) sequences. A clade distinct from the Onygenaceae was found to encompass Ajellomyces (including the anamorph genera Blastomyces, Emmonsia and Histoplasma) and Paracoccidioides brasiliensis. The members of this lineage are saprobic and pathogenic vertebrate-associated taxa distinguished by their globose ascomata with coiled appendages, muricate globose or oblate ascospores, and lack of keratinolytic activity. Anamorphs are solitary aleurioconidia or irregular alternate arthroconidia. Based on molecular data and on morphological and physiological similarities among these taxa, we propose the new family, Ajellomycetaceae.  相似文献   

14.
This paper reviews the historical treatment of the tribe Sabethini and genus-group taxa and examines the unusual life histories associated with the group. Although recognized by taxonomists as distinct, the taxonomic position of sabethines has been questioned and their rank within the family Culicidae unstable. In order to evaluate the current status of the classification of the tribe a cladistic analysis is performed. Thirty-seven taxa are selected from within the Sabethini and two outgroups were chosen from the tribe Aedini. Exemplars are selected from genus-group taxa world-wide and new and traditional character systems examined in larval, pupal and adult life stages. The results firmly establish the sabethines as a monophyletic group. However, the genera Runchomyia , Tripteroides and Wyeomyia are not demonstrably monophyletic. In addition, the data support the New World taxa as a monophyletic group to a paraphyletic assemblage of Old World taxa. The pattern displayed by the cladogram suggests the ability to vector arboviruses has arisen more than once in mosquitoes.  相似文献   

15.
选择28S rDNA D2区基因,针对GenBank中姬小蜂科总计542条相关序列,借助Blast Align、MUSCLE及TNT等生物信息学软件进行计算分析,提出了一种基于亚科水平的姬小蜂科快速DNA分类鉴定方法。建树结果对目前分类系统中姬小蜂科4亚科分类体系(Bouek,1988)予以支持;综合分析结果基本支持对于姬小蜂亚科以及灿小蜂亚科的分族、分属方法。同时对地位不明的两属Anselmella和Ophelimus的分类学地位提出了假设。  相似文献   

16.
One of the most recent classifications of Meloidae is based on the assumption that phoretic first‐instar larvae evolved twice in the family, once in Meloinae and again in Nemognathinae. Within Meloinae, this scheme places all presumed phoretic taxa in Meloini regardless of other characteristics. This paper challenges this classification with a cladistic analysis of all meloid genera whose first‐instar larvae were available for study. It concludes that phoresy evolved several times in Meloinae alone and that Meloini, when defined to include all phoretic genera, is polyphyletic. Cladistic support also is presented for four subfamilies of Meloidae and for several of the traditional tribes recognized in recent classifications.  相似文献   

17.
Molecular phylogenetic relationships of the wood-feeding cockroach genera Salganea and Panesthia (Blaberidae; Panesthiinae) in East Asian Islands (Ryukyu archipelago and Taiwan Island) were analyzed based on the DNA sequence of the complete mitochondrial cytochrome oxidase II gene. Unweighted parsimony analysis resulted in high bootstrap support for relationships within Panesthia taxa; however, some nodes were unresolved between members of Salganea. Comparison of the number of transitions and transversions with genetic distance at each codon position suggested that saturation of third-codon substitutions has occurred between certain pairs of taxa. Consequently, differential weighting of substitutions at these sites was performed, which resulted in a substantial increase in resolution of Salganea relationships. The inferred phylogenies for both genera displayed good correspondence to the geographical locations of populations but however did not agree with previous subspecies designations based on morphological characters. It appears that both cockroach genera invaded the Ryukyu archipelago from the Taiwan region via a land-bridge present in the Miocene period. Invasion of the main islands of Japan by these cockroaches most likely occurred before the formation of the Tokara Tectonic Strait. Our study suggests that several barriers to gene flow have arisen and persisted over the past approximately 10 million years, which have caused segregation and vicariant speciation of the cockroach taxa of this region.  相似文献   

18.
Nucleotide sequences of a chloroplast rDNA region including 8 bp from the 3' end of 23S rDNA-ITS2-4.5S rDNA-ITS3-5S rDNA-ITS4 (approximately 800 bp) were determined in 25 species of Lycopodiaceae and two species of the genus Isoetes. The rate of molecular evolution of spacers significantly varied in different Lycopsida taxa. A phylogenetic analysis by the neighbor-joining (NJ) method revealed that the family Lycopodiaceae is monophyletic. The topology of phylogenetic trees suggests the isolation of four or probably five genera in family Lycopodiaceae. For these genera, synapomorphic indels were detected. The obtained data were compared with the results of phylogenetic analysis of Lycopsida with regard to other sequences. The relationships of taxa within the family Lycopodiaceae is discussed.  相似文献   

19.
We analyzed nucleotide variation at four loci for 75 species to produce a phylogenetic hypothesis for the Meliphagidae, and to examine the evolution and biogeographic history of the Meliphagidae. Both maximum parsimony and Bayesian methods of phylogenetic analysis were employed. The family was found to be monophyletic, though the genera Certhionyx, Anthochaera, and Phylidonyris were not. Four major clades were recovered and the spinebills (Acanthorhynchus) formed the sister clade to the remainder of the family in most analyses. The Australian endemic arid-adapted chats (Epthianura, Ashbyia) were found to be nested deeply within the family Meliphagidae. No evidence was found to support the hypothesis of separate New Guinean and Australian endemic radiations, nor of a close phylogenetic relationship between taxa from the New Guinea highlands and those from Australian northern rainforests.  相似文献   

20.
? Premise of the study: Taxonomic groups have often been recognized on the basis of geographic distinctions rather than accurately representing evolutionary relationships. This has been particularly true for temperate and tropical members from the same family. Polygonaceae exemplifies this problem, wherein the woody tropical genera were segregated from temperate members of the family and placed in the subfamily Polygonoideae as two tribes: Triplarideae and Coccolobeae. Modern phylogenetic studies, especially when inferred from many lines of evidence, can elucidate more probable hypotheses of relationships. This study builds on previous work in the family and aims to test the traditional classification of the tropical woody taxa, which have been understudied and undersampled compared to their temperate relatives. ? Methods: A phylogenetic study was undertaken with expanded sampling of the tropical genera with data from five plastid markers (psbA-trnH, psaI-accD, matK, ndhF, and rbcL), nuclear ribosomal DNA (ITS) and morphology. ? Key results: Results support the placement of nine of 12 genera of the Triplarideae and Coccolobeae within Eriogonoideae, in which these genera form a paraphyletic assemblage giving rise to Eriogoneae. The remaining woody tropical genera excluded from Eriogonoideae occur in the paleotropics. ? Conclusions: Traditional characters used to delimit Coccolobeae and Triplarideae are not useful for defining monophyletic groups. The six-tepal condition is derived from the five-tepal condition, and unisexual flowers have arisen multiple times in different sexual systems. Ruminate endosperm has arisen multiple times in the family, suggesting this character is highly plastic.  相似文献   

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