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1.
The genus Lecidea Ach. sensu lato (sensu Zahlbruckner) includes almost 1200 species, out of which only 100 species represent Lecidea sensu stricto (sensu Hertel). The systematic position of the remaining species is mostly unsettled but anticipated to represent several unrelated lineages within Lecanoromycetes. This study attempts to elucidate the phylogenetic placement of members of this heterogeneous group of lichen-forming fungi and to improve the classification and phylogeny of Lecanoromycetes. Twenty-five taxa of Lecidea sensu lato and 22 putatively allied species were studied in a broad selection of 268 taxa, representing 48 families of Lecanoromycetes. Six loci, including four ribosomal and two protein-coding genes for 315- and 209-OTU datasets were subjected to maximum likelihood and Bayesian analyses. The resulting well supported phylogenetic relationships within Lecanoromycetes are in agreement with published phylogenies, but the addition of new taxa revealed putative rearrangements of several families (e.g. Catillariaceae, Lecanoraceae, Lecideaceae, Megalariaceae, Pilocarpaceae and Ramalinaceae). As expected, species of Lecidea sensu lato and putatively related taxa are scattered within Lecanoromycetidae and beyond, with several species nested in Lecanoraceae and Pilocarpaceae and others placed outside currently recognized families in Lecanorales and orders in Lecanoromycetidae. The phylogenetic affiliations of Schaereria and Strangospora are outside Lecanoromycetidae, probably with Ostropomycetidae. All species referred to as Lecidea sensu stricto based on morphology (including the type species, Lecidea fuscoatra [L.] Ach.) form, with Porpidia species, a monophyletic group with high posterior probability outside Lecanorales, Peltigerales and Teloschistales, in Lecanoromycetidae, supporting the recognition of order Lecideales Vain. in this subclass. The genus name Lecidea must be redefined to apply only to Lecidea sensu stricto and to include at least some members of the genus Porpidia. Based on morphological and chemical similarities, as well as the phylogenetic relationship of Lecidea pullata sister to Frutidella caesioatra, the new combination Frutidella pullata is proposed here.  相似文献   

2.
Nuclear-encoded SSU rDNA sequences have been obtained from 64 strains of conjugating green algae (Zygnemophyceae, Streptophyta, Viridiplantae). Molecular phylogenetic analyses of 90 SSU rDNA sequences of Viridiplantae (inciuding 78 from the Zygnemophyceae) were performed using complex evolutionary models and maximum likelihood, distance, and maximum parsimony methods. The significance of the results was tested by bootstrap analyses, deletion of long-branch taxa, relative rate tests, and Kishino-Hasegawa tests with user-defined trees. All results support the monophyly of the class Zygnemophyceae and of the order Desmidiales. The second order, Zygnematales, forms a series of early-branching clades in paraphyletic succession, with the two traditional families Mesotaeniaceae and Zygnemataceae not recovered as lineages. Instead, a long-branch Spirogyra/Sirogonium clade and the later-diverging Netrium and Roya clades represent independent clades. Within the order Desmidiales, the families Gonatozygaceae and Closteriaceae are monophyletic, whereas the Peniaceae (represented only by Penium margaritaceum) and the Desmidiaceae represent a single weakly supported lineage. Within the Desmidiaceae short internal branches and varying rates of sequence evolution among taxa reduce the phylogenetic resolution significantly. The SSU rDNA-based phylogeny is largely congruent with a published analysis of the rbcL phylogeny of the Zygnemophyceae (McCourt et al. 2000) and is also in general agreement with classification schemes based on cell wall ultrastructure. The extended taxon sampling at the subgenus level provides solid evidence that many genera in the Zygnemophyceae are not monophyletic and that the genus concept in the group needs to be revised.  相似文献   

3.
CLADISTICS AND FAMILY LEVEL CLASSIFICATION OF THE GENTIANALES   总被引:1,自引:0,他引:1  
Abstract— The most recent classification of the angiosperm order Gentianales (Thorne, 1992) includes four principal families: Apocynaceae, Gentianaceae, Loganiaceae, and Rubiaceae. Ever since Bentham (1857) the status of Loganiaceae has been questioned, and several segregates of that family have been proposed both before and after his treatment. In this study we present cladistic results that show Loganiaceae, sensu lato, to be a paraphyletic group definable only by plesiomorphies, with members showing closest relationships to other families of the order. As the impact of different character-state representations of polymorphic terminals remains largely untested, our morphological and phytochemical data were analysed both with restricted polymorphism coding as well as with the monomorphic "subtaxon" recoding method of Nixon and Davis (1991). Both approaches yield highly compatible results, and we here discuss a new classification of the Gentianales based on (i) monophyletic groups identified by outgroup analysis, and (ii) the maximal portrayal of evidence provided by subtaxon polymorphism recoding. Most prominently, the Loganiaceae sensu lato are divided into four segregate families, two previously named (Loganiaceae sensu stricto and Strychnaceae), and two defined as a result of this study (Gelsemiaceae, L. Struwe & V. A. Albert, stat. nov. and Geniostomaceae, L. Struwe & V. A. Albert, fam. nov.). Apocynaceae (incl. Asclepiadaceae), Gentianaceae (incl. Loganiaceae—Potalieae), and Rubiaceae remain as monophyletic families. Outgroup analysis supports both the monophyly of the Gentianales as well as the exclusion from the order of Buddleja, Desfontainia, Plocosperma, Polypremum , and Retzia (all Loganiaceae sensu Leeuwenberg and Leenhouts).  相似文献   

4.
Abstract: The nuclear LSU rRNA gene was examined in order to evaluate the current phylogeny of ascomycetes, which is mainly based on nuclear SSU rRNA data. Partial LSU rRNA gene sequences of 19 ascomycetes were determined and aligned with the corresponding sequences of 13 other ascomycetes retrieved from Genbank, including all classes traditionally distinguished and most of the recently accepted classes. The classification based on SSU rDNA data and morphological characters is supported, while the traditional classification and classifications based on the ascus type are rejected. Ascomycetes with perithecia and cleistothecia form monophyletic groups, while the discomycetes are a paraphyletic assemblage. The Pezizales are basal to all other filamentous ascomycetes. The monophyly of Loculoascomycetes is uncertain. The results of the LSU rDNA analysis agree with those of the SSU rDNA and RPB2 gene analyses, suggesting that most classes circumscribed in the filamentous ascomycetes are monophyletic. The branching order and relationships among these classes, however, cannot be elucidated with any of these data sets.  相似文献   

5.
The fishes currently recognized as members of the order Gasterosteiformes (sticklebacks, pipefishes, and their relatives) number 278 species, classified into two suborders (Gasterosteoidei and Syngnathoidei), 11 families and 71 genera. Members of this group exhibit unique appearances, many of which are derived from armored bodies with bony plates in various forms. Although recent molecular phylogenetic studies have repeatedly questioned the monophyly of this order, none of the studies examined all of the representative families and the phylogenetic reality of the group has remained unclear. In this study, we examined whole mitochondrial genome (mitogenome) sequences from 13 gasterosteiform species representing all 11 families in the order, and subjected them to partitioned maximum likelihood and Bayesian analyses, with additional data from other percomorphs and outgroups (75 mitogenome sequences considered overall, including 10 newly determined). The resultant phylogenies indicated explicitly that previously recognized members of Gasterosteiformes had diverged basally within the Percomorpha into three different clades with the following subgroups: Syngnathoidei, Gasterosteoidei (minus Indostomidae), and Indostomidae. Monophyly of the order Gasterosteiformes and any combinations of the three subgroups were confidently rejected by statistical tests. Syngnathoidei (together with Dactylopteroidei) formed a monophyletic group, a sister-group relationship between Gasterosteoidei (minus Indostomidae) and Zoarcoidei was reconfirmed and Indostomidae was nested within the Synbranchiformes, rendering the latter group paraphyletic. Our study demonstrates a new perspective of gasterosteiform phylogeny, which will provide fundamental information for future studies of phylogeny, systematics, and evolution.  相似文献   

6.
We performed a molecular phylogenetic study of the Anthocoridae, the flower bugs, based on maximum likelihood, maximum parsimony, and Bayesian analyses of ~ 3000 base pairs (bp) of DNA sequence from the mitochondrial 16S rRNA and nuclear 18S rRNA and 28S rRNA genes for 44 taxa. Our phylogenetic analyses indicates that (i) the tribe Cardiastethini (Dufouriellini) could be a paraphyletic group, as the genera Amphiareus and Dysepicritus are not included in the tribe; (ii) the main subgroups, Oriini and Anthocorini, are monophyletic within Anthocoridae; (iii) three tribes of Blaptostethini, Xylocorini, and Scolopini are separated from the main anthocorid clade which is composed of Anthocorini, Cardiastethini, and Oriini, suggesting that Anthocoridae could not be monophyletic. We compared our molecular phylogeny to previous hypotheses of evolutionary relationships within Cimicoidea based on different anthocorid classification systems using alternative hypothesis tests (Kishino-Hasegawa and Shimodaira-Hasegawa tests). BayesTraits were used to examine the ancestral character states inferring historical habitat patterns of the Anthocoridae. Reconstruction of the ancestral habitat patterns of the Anthocoridae suggests that dead plants may have served as an important habitat for the common ancestor of anthocorids. The biological events such as diversification of angiosperms and anthocorid prey might have provided anthocorids with more habitat options, such as living plants; thereafter, Anthocorini and Amphiareus appeared to have evolved increasingly specialized habitat relationships.  相似文献   

7.
Currently, the phylum Gastrotricha is divided into the orders Macrodasyida and Chaetonotida, with the structure of the myoepithelial pharynx being an important distinguishing feature. Macrodasyida currently has six recognized families, and Chaetonotida comprises seven families. However, within-group relationships are poorly understood. To arrive at a better understanding of gastrotrich systematics and phylogeny, we performed the first cladistic analysis of nearly all known gastrotrich genera using 71 morphological characters. Results suggest that the Gastrotricha is a monophyletic group (supported by 82% of bootstrap replications) with its most primitive taxa distributed among the families Dactylopodolidae and Neodasyidae. Monophyly of Macrodasyida and Chaetonotida was supported by 90% and 52% bootstrap replications, respectively. Within the Macrodasyida, the families Dactylopodolidae, Turbanellidae, Macrodasyidae, and Thaumastodermatidae all formed monophyletic clades. The families Planodasyidae and Lepidodasyidae were paraphyletic. Among the Chaetonotida, the marine family Xenotrichulidae was monophyletic, supported by 51% of bootstrap replications. A second clade containing all freshwater families was supported by 62% bootstrap values. However, Chaetonotidae were paraphyletic. Using this analysis as a framework, we now can explore possible patterns of evolution within it, and arrive at a consensus of the gastrotrich ground pattern. Moreover, in future molecular studies of metazoan phylogeny, we will be able to select gastrotrich species that are more appropriate representatives of the phylum.  相似文献   

8.
Phylogenetic relationships of lichen-forming discomycetes and their relatives in the class Lecanoromycetes were examined by using nuclear large subunit and mitochondrial small subunit ribosomal DNA sequences. Ninety-eight partial sequences of 53 ascomycetes were generated and aligned with the corresponding sequences retrieved from GenBank resulting in an alignment of 100 taxa that was analyzed using a Bayesian approach with Markov chain Monte Carlo (B/MCMC) methods. The analysis revealed the monophyly of the Lecanoromycetes with two major clades: one clade including the monophyletic orders Graphidales and Ostropales and the paraphyletic Gyalectales, the other clade including the monophyletic Lecanorales (incl. Caliciales, Peltigerales, and Teloschistales) and a clade containing the polyphyletic Agyriales, a yet undescribed order Umbilicariales (including Elixiaceae and Umbilicariaceae), and Pertusariales. The monophyly of the Pertusariales was not resolved. Testing of alternative hypotheses revealed that a placement of Chaetothyriomycetes and Eurotiomycetes within Lecanoromycetes and the monophyly of Agyriales s. lat. (incl. Elixiaceae and Schaereriaceae) and Ostropales s. lat. (incl. Graphidales) can be rejected, while monophyly of Gyalectales and the Pertusariales and placement of Umbilicariales on the Lecanorales branch cannot be rejected with the current data set.  相似文献   

9.
The phylogeny and systematic position of Gomphillaceae was reconstructed using a combined Bayesian analysis of nuclear LSU rDNA and mitochondrial SSU rDNA sequences. Twenty-four partial sequences of 12 taxa (11 Gomphillaceae and one Asterothyriaceae) plus two new sequences of Stictis radiata (Ostropales outgroup) were generated and aligned with the corresponding sequences retrieved from GenBank, resulting in an alignment of 82 taxa that was analyzed using a Bayesian approach with Markov chain Monte Carlo (B/MCMC) methods. Our results confirm Gomphillaceae sensu Vezda and Poelt plus Asterothyriaceae to be a monophyletic group, with an unresolved relationship between the two families. Placement of Gomphillaceae and Asterothyriaceae within Ostropales sensu Kauff and Lutzoni, as sister of Thelotremataceae, also is strongly supported. Alternative hypotheses placing Gomphillaceae in Lecanorales (Cladoniaceae), Agyriales (Baeomycetaceae) or within bitunicate Ascomycota (Arthoniomycetes, Chaetothyriomycetes, Dothideomycetes) were rejected with our dataset. After recent synonymization of Dimerella with Coenogonium (Ostropales: Coenogoniaceae), we propose the new combination Coenogonium pineti (one of our Ostropales outgroup taxa in this analysis).  相似文献   

10.
Siphonaptera (fleas) is a highly specialized order of holometabolous insects comprising ~2500 species placed in 16 families. Despite a long history of extensive work on flea classification and biology, phylogenetic relationships among fleas are virtually unknown. We present the first formal analysis of flea relationships based on a molecular matrix of four loci (18S ribosomal DNA, 28S ribosomal DNA, Cytochrome Oxidase II, and Elongation Factor 1‐alpha) for 128 flea taxa from around the world representing 16 families, 25 subfamilies, 26 tribes, and 83 flea genera with eight outgroups. Trees were reconstructed using direct optimization and maximum likelihood techniques. Our analysis supports Tungidae as the most basal flea lineage, sister group to the remainder of the extant fleas. Pygiopsyllomorpha is monophyletic, as are the constituent families Lycopsyllidae, Pygiopsyllidae, and Stivaliidae, with a sister group relationship between the latter two families. Macropsyllidae is resolved as sister group to Coptopsyllidae with moderate nodal support. Stephanociricidae is monophyletic, as are the two constituent subfamilies Stephanocircinae and Craneopsyllinae. Vermipsyllidae is placed as sister group to Jordanopsylla. Rhopalopsyllidae is monophyletic as are the two constituent subfamilies Rhopalopsyllinae and Parapsyllinae. Hystrichopsyllidae is paraphyletic with Hystrichopsyllini placed as sister to some species of Anomiopsyllini and Ctenopariini placed as sister to Carterettini. Ctenophthalmidae is grossly paraphyletic with the family broken into seven lineages dispersed on the tree. Most notably, Anomiopsyllini is paraphyletic. Pulicidae and Chimaeropsyllidae are both monophyletic and these families are sister groups. Ceratophyllomorpha is monophyletic and includes Ischnopsyllidae, Ceratophyllidae, and Leptopsyllidae. Leptopsyllidae is paraphyletic as are its constituent subfamilies Amphipsyllinae and Leptopsyllinae and the tribes Amphipsyllini and Leptopsyllini. Ischnopsyllidae is monophyletic. Ceratophyllidae is monophyletic, with a monophyletic Dactypsyllinae nested within Ceratophyllinae, rendering the latter group paraphyletic. Mapping of general host associations on our topology reveals an early association with mammals with four independent shifts to birds. © The Willi Hennig Society 2008.  相似文献   

11.
Phylogeny of caddisflies (Insecta, Trichoptera)   总被引:2,自引:0,他引:2  
Trichoptera are holometabolous insects with aquatic larvae that, together with the Lepidoptera, comprise the Amphiesmenoptera. Previous phylogenetic hypotheses and progress on our ongoing data collection are summarized. Fragments of the large and small subunit nuclear ribosomal RNAs (D1, D3, V4–5), the nuclear elongation factor 1 alpha gene and a fragment of mitochondrial cytochrome oxidase 1 (COI) were sequenced, and molecular data were combined with previously published morphological data. Equally and differentially weighted parsimony analyses were conducted in order to present a phylogeny of Trichoptera, including 43 of 45 families. Our phylogeny closely resembles that proposed by Herbert Ross with respect to the relationships among suborders, with a monophyletic Annulipalpia at the base of the tree, and a clade consisting of Spicipalpia plus a monophyletic Integripalpia. The monophyly of Spicipalpia is weakly supported in the combined equally weighted analysis, and Spicipalpia is paraphyletic in the differentially weighted analysis. Within Integripalpia, our phylogeny recovered monophyletic Plenitentoria, Brevitentoria and Sericostomatoidea. Leptoceroidea was unresolved in the equally weighted analysis and monophyletic in the differentially weighted analysis. Within Annulipalpia, we recovered a basal but paraphyletic Philopotamoidea and a monophyletic Hydropsychoidea.  相似文献   

12.
Recent revisions of generic relationships in the pyrenocarpous lichen familyTrichotheliaceaeby J. Hafellner & K. Kalb (based on perithecial pigmentation and ascus structure) and R. C. Harris (based on morphological, chemical and environmental trends) are assessed. However, most of their conclusions are rejected because the authors used shared or variable characters, insufficient specimens and highly disjointed groups of species.  相似文献   

13.
Nucleotide sequences from mitochondrial (12S rRNA) and nuclear (growth hormone receptor) genes were used to investigate phylogenetic relationships among South American hystricognath rodents of the superfamily Octodontoidea, with special emphasis on the family Octodontidae. Relationships among most taxa were well resolved by a combined analysis of both genes, and the molecular phylogeny was used to address several long-standing phylogenetic problems. The family Abrocomidae was the most basal lineage within the superfamily Octodontoidea, sensu stricto, and the family Ctenomyidae was sister to the family Octodontidae, followed by a monophyletic group containing the families Myocastoridae and Echimyidae. A basic dichotomy was observed within the family Octodontidae. The Argentine desert specialists, Tympanoctomys and Octomys, grouped separate from Octodontomys, which was sister to a clade containing a monophyletic Octodon and a clade represented by species of Aconaemys and Spalacopus. Aconaemys was paraphyletic relative to Spalacopus. The phylogeny was used as an interpretive framework for an examination of variation in several non-molecular characters. The primitive diploid number for most of the octodontoids was determined to be between 46 and 56, and the primitive genome size 8.2 pg. Members of the Octodontidae appeared to be derived from an ancestral stock occupying lower elevations in scrub habitat. Furthermore, estimates of divergence time from the molecular data provided a temporal perspective for changes in plant communities, which demonstrated turnover and diversification in response to climatic and geologic events occurring in the Miocene through the Pleistocene.  相似文献   

14.
The phylogeny of the Aplysiidae is investigated, based on 37 morphological and histological characters polarized a priori by outgroup comparison. The Aplysiidae represents a monophyletic taxon comprising two distinct clades: Aplysiinae and Dolabellinae + Dolabriferinae + Notarchinae. The traditional classification of Longicommissurata (Aplysiinae + Dolabellinae) is no longer valid since the Longicommissurata are paraphyletic. However, the Brevicommissurata (Dolabriferinae + Notarchinae) form a monophyletic group. Within the Dolabriferinae two sister-groups can be distinguished: Dolabrifera and Phyllaplysia + Petalifera petalifera . The genus Petalifera is paraphyletic. Based on the present phylogeny, several aspects of the evolution of the Aplysiidae are discussed.  相似文献   

15.
Of all the superfamilies within the megadiverse order Coleoptera (Insecta), Cucujoidea (Cucujiformia) is arguably the most problematic taxonomically. The families comprising Cucujidae s.l. (Silvanidae, Laemophloeidae, Passandridae and Cucujidae s.s. represent a large portion of cucujoid diversity. Herein we present the results of a rigorous molecular phylogenetic analysis of Cucujidae s.l. using maximum‐likelihood and Bayesian analyses of seven genes. Representatives of over half of the families of Cucujoidea (excluding the cerylonid series), as well as a broad sampling of Silvanidae and Laemophloeidae, were analysed. The monophyly of Cucujidae s.l. is rejected but a subgrouping of taxa that may form the core of a natural cucujoid lineage is recovered. This clade consists of two large monophyletic groups including several families each. Relationships among these smaller cucujoid groups are discussed, including several novel phylogenetic hypotheses, whereas morphological characters considered significant for classification in Cucujidae s.l. are evaluated in light of these phylogenetic hypotheses. Silvaninae, Telephanini, Brontini and Brontinae are recovered as monophyletic in the Bayesian analysis, but the former two are recovered as paraphyletic in the maximum‐likelihood analysis. Our results support the placement of Psammoecus Latreille within Telephanini and also recover a paraphyletic Telephanus Erichson. Silvaninae is divided into three lineages, each representing a potential tribal lineage. Laemophloeidae is rendered paraphyletic in all analyses by Propalticidae and the latter is herein formally transferred to Laemophloeidae stat.n . Several suprageneric laemophloeid clades are recovered and discussed as potential higher‐level groups. Laemophloeus Dejean is not recovered as monophyletic.  相似文献   

16.
淡水豚类4个代表属「白暨豚(Lipotes)、恒河豚(Platanista)、弗西豚(Pontoporia)和亚河豚(Inia)」mtDNA 12S rRNA基因的序列差异水平,高于其他齿鲸类科间的差异,特别是远远高于海豚总科内的科间差异。研究结果支持它们应归属于不同的科,即白暨豚科(Lipotiidae)、恒河豚科(Platanistidae)、弗西豚科(Pontoporidae)和亚河豚科(I  相似文献   

17.
The molecular phylogeny of the family Diadocidiidae (Diptera: Sciaroidea) is reconstructed based on the combined analysis of four mitochondrial (12S, 16S, COI, cytB) and two nuclear (28S, ITS2) gene markers. All the analyses strongly support Diadocidiidae as a monophyletic group. Genus Diadocidia Ruthe, 1831 includes monophyletic subgenera Diadocidia s. str. and Taidocidia Papp and ?ev?ík (Acta Zoologica Academiae Scientiarum Hungaricae, 51 , 2005b, 329). The monophyly of Adidocidia La?tovka & Matile, 1972 was not confirmed. The position of Diadocidiidae and relationships of the families within the infraorder Bibionomorpha are demonstrated in the analyses based on three gene markers (28S, 12S and 16S). The Bayesian and maximum likelihood analyses of 10 families of Bibionomorpha revealed Sciaridae as the closest relative of Diadocidiidae. Most of the currently recognised extant families of Bibionomorpha proved to be monophyletic. The family Keroplatidae revealed as paraphyletic, with the genera of Macrocerinae being more related to Cecidomyiidae, but the support is low.  相似文献   

18.
Ancestral state reconstructions of morphological or ecological traits on molecular phylogenies are becoming increasingly frequent. They rely on constancy of character state change rates over trees, a correlation between neutral genetic change and phenotypic change, as well as on adequate likelihood models and (for Bayesian methods) prior distributions. This investigation explored the outcomes of a variety of methods for reconstructing discrete ancestral state in the ascus apex of the Lecanorales, a group containing the majority of lichen-forming ascomycetes. Evolution of this character complex has been highly controversial in lichen systematics for more than two decades. The phylogeny was estimated using Bayesian Markov chain Monte Carlo inference on DNA sequence alignments of three genes (small subunit of the mitochondrial rDNA, large subunit of the nuclear rDNA, and largest subunit of RNA polymerase II). We designed a novel method for assessing the suitable number of discrete gamma categories, which relies on the effect on phylogeny estimates rather than on likelihoods. Ancestral state reconstructions were performed using maximum parsimony and maximum likelihood on a posterior tree sample as well as two fully Bayesian methods. Resulting reconstructions were often strikingly different depending on the method used; different methods often assign high confidence to different states at a given node. The two fully Bayesian methods disagree about the most probable reconstruction in about half of the nodes, even when similar likelihood models and similar priors are used. We suggest that similar studies should use several methods, awaiting an improved understanding of the statistical properties of the methods. A Lecanora-type ascus may have been ancestral in the Lecanorales. State transformations counts, obtained using stochastic mapping, indicate that the number of state changes is 12 to 24, which is considerably greater than the minimum three changes needed to explain the four observed ascus apex types. Apparently, the ascus in the Lecanorales is far more apt to change than has been recognized. Phylogeny corresponds well with morphology, although it partly contradicts currently used delimitations of the Crocyniaceae, Haematommataceae, Lecanoraceae, Megalariaceae, Mycoblastaceae, Pilocarpaceae, Psoraceae, Ramalinaceae, Scoliciosporaceae, and Squamarinaceae.  相似文献   

19.
Abstract: The Lichinales are a group of lichenized ascomycetes that almost exclusively possess cyanobacteria as their primary photobiont and are hitherto separated from the Lecanorales, the major group of lichenized ascomycetes, by thallus structure, ascoma ontogeny, ascus structure and ascus function. The relationship of the two families Peltulaceae and Lichinaceae, both placed within the Lichinales, with the Heppiaceae, placed within the Lecanorales, was investigated, as well as a possible sister group relationship of the Lichinales to the Lecanorales. Phylogenetic analyses included non-molecular data as well as 18S rDNA sequence data. The monophyly of the Lichinales including the family Heppiaceae and a sister group relationship of Lichinales and Lecanorales, based on the shared presence of lecanoralean asci, are proposed in a morphological hypothesis. Parsimony and distance analyses of 18S rDNA sequence data strongly support the monophyly of the Lichinales, including all three families. Therefore, the presence of rostrate, lecanoralean asci in Peltula and part of the Lichinaceae suggests that this ascus type is an autapomorphy of the monophyletic Lichinales. Furthermore, the occurrence of prototunicate asci in the Heppiaceae and most of the Lichinaceae is autapomorphic and was gained independently by reduction of the rostrate ascus. The 18S rDNA analysis did not reject the non-molecular hypothesis of a sister group relationship of the Lichinales and the Lecanorales as based on ascus characters. The alternative placement of the Lichinales as the sister group of all inoperculate euascomycetes excluding the Sordariomycetes and most of the Leotiales in the gene tree received unsufficient bootstrap support and no support from any non-molecular data and consequently was rejected.  相似文献   

20.
Phylogenetic relationships among the apocritan wasps were investigated using comparative sequence data from the mitochondrial 16S rRNA gene. The gene fragment contained three length polymorphic regions. Relationships that were not sensitive to the alignment procedure are discussed, but should be considered as preliminary only. Maximum parsimony analysis recovered the Evaniomorpha ( sensu Rasnitsyn, 1988) as a monophyletic group, with the pattern of relationships Ceraphronoidea + (Evanioidea + [Megalyroidea + Trigonalyoidea]). The Proctotrupomorpha ( sensu Rasnitsyn, 1988) were also recovered as a monophyletic group, while the Proctotrupoidea were recovered as paraphyletic. The Proctotrupoidea were only monophyletic if the Platygastroidea and Chalcidoidea were included (i.e. Proctotrupomorpha). Relationships of the Proctotrupomorpha that were supported by this analysis included Diapriidae + (Platygastroidea + Chalcidoidea), and the Vanhorniidae falling inside the Proctotrupidae. However, resolution of other relationships within the Proctotrupomorpha was less reliable, as indicated by low decay indices and low bootstrap proportions. Similarly, the placement of the Cynipoidea relative to the other apocritan lineages was also not recovered confidently.  相似文献   

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