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1.
C. N. Page 《Plant Systematics and Evolution》1980,135(1-2):71-79
This study surveys the micromorphological surface structure of the leaves of the conifer genusAgathis (Araucariaceae) from throughout the range of the genus (Malaysia to New Zealand and Fiji) as seen with the scanning electron microscope. These data confirm that the vegetative parts ofAgathis are taxonomically highly conservative, but suggest the Melanesian and New Zealand elements to be distinctive from those of the rest of the genus, and from one another. Conclusions are compared with those that have been derived from studies based on other characters. 相似文献
2.
Bente Eriksen 《Plant Systematics and Evolution》1993,186(1-2):17-32
Floral morphology and anatomy of 15 genera in thePolygalaceae have been studied. The pentamerous origin of the polygalaceous flower is confirmed and shown to apply to all genera in the family. The keel is interpreted as a single petal, and the androecium as of bimeric origin. Vascular structure in the receptacles ofCarpolobia andMonnina subg.Monnina is described in detail, and a compilation of results, focusing on the vascular supply for the androecium and gynoecium, is given for all genera. Based on similarities and differences in vascularization it is concluded that present taxonomy, in particular the tribal system, needs to be reviewed. 相似文献
3.
Baab KL 《Journal of human evolution》2008,54(6):827-847
The taxonomic status of Homo erectus sensu lato has been a source of debate since the early 1980s, when a series of publications suggested that the early African fossils may represent a separate species, H. ergaster. To gain further resolution regarding this debate, 3D geometric morphometric data were used to quantify overall shape variation in the cranial vault within H. erectus using a new metric, the sum of squared pairwise Procrustes distances (SSD). Bootstrapping methods were used to compare the H. erectus SSD to a broad range of human and nonhuman primate samples in order to ascertain whether variation in H. erectus most clearly resembles that seen in one or more species. The reference taxa included relevant phylogenetic, ecological, and temporal analogs including humans, apes, and both extant and extinct papionin monkeys. The mean cranial shapes of different temporogeographic subsets of H. erectus fossils were then tested for significance using exact randomization tests and compared to the distances between regional groups of modern humans and subspecies/species of the ape and papionin monkey taxa. To gauge the influence of sexual dimorphism on levels of variation, comparisons were also made between the mean cranial shapes of single-sex samples for the reference taxa. Results indicate that variation in H. erectus is most comparable to single species of papionin monkeys and the genus Pan, which included two species. However, H. erectus encompasses a limited range of variation given its extensive geographic and temporal range, leading to the conclusion that only one species should be recognized. In addition, there are significant differences between the African/Georgian and Asian H. erectus samples, but not between H. ergaster (Georgia+Africa, excluding OH 9 and Daka) and H. erectus sensu stricto. This finding is in line with expectations for intraspecific variation in a long-lived species with a wide, but probably discontinuous, geographic distribution. 相似文献
4.
Sequence comparisons and a revised classification of the Euglenophyceae were based on 92 new SSU rDNA sequences obtained from strains of Euglena, Astasia, Phacus, Trachelomonas, Colacium, Cryptoglena, Lepocinclis, Eutreptia, Eutreptiella and Tetreutreptia. Sequence data also provided molecular signatures for taxa from genus to class level in the SSU rRNA secondary structure, revealed by a novel approach (search for non-homoplasious synapomorphies) and used for taxonomic diagnoses. Photosynthetic euglenoids and secondary heterotrophs formed a clade, designated as Euglenophyceae (emend.) with two orders: Euglenales and Eutreptiales. The mostly marine Eutreptiales (Eutreptia, Eutreptiella; not Distigma) comprised taxa with two or four emergent flagella (the quadriflagellate Tetreutreptia was integrated within Eutreptiella). The Euglenales (freshwater genera with < or = one emergent flagellum) formed nine clades and two individual branches (single strains); however, only two clades were congruent with traditional genera: Trachelomonas (incl. Strombomonas) and Colacium. Euglena was polyphyletic and diverged into four independent clades (intermixed with Astasia, Khawkinea and Lepocinclis) and two individual branches (e.g. E. polymorpha). Phacus was also subdivided into Phacus s. str. and two combined lineages (mixed with Lepocinclis spp. or Cryptoglena). In consequence, Euglena (s. str.), Phacus and other genera were emended and one lineage (mixed Phacus/Lepocinclis-clade) was recognized as the previously neglected genus Monomorphina Mereschkowsky (1877). The sister clade of Phacus s. str. (mixed Euglena/Lepocinclis-clade) was identified as Lepocinclis Perty (emended). 相似文献
5.
Roger Eriksson 《Plant Systematics and Evolution》1994,190(1-2):31-47
The affinities ofCyclanthaceae are discussed, and it is concluded that the sister-group to this family is most probablyPandanaceae. A hypothesis of generic relationships inCyclanthaceae, based on cladistic methods, is presented. Bootstrap analysis and Bremer support (decay index) have been used to test the strength of individual clades, and the result is compared with previously made phylogenetic analyses. TheSphaeradenia group (Chorigyne, Stelestylis, Sphaeradenia, andLudovia) is supported as monophyletic and acceptably resolved, while theAsplundia group (remaining genera inCarludovicoideae) may be paraphyletic, with largely uncertain relationships. A formal recognition of these groups is therefore not justified. The probable character evolution inCarludovicoideae is discussed. 相似文献
6.
7.
A reassessment of cleistothecia as a taxonomic character 总被引:1,自引:1,他引:0
The morphology of sexual fruit bodies has been historically regarded as a key character in fungal taxonomy. In the 1970s the class Plectomycetes was recognized in order to classify the cleistothecial ascomycetes. However, recent analysis of DNA sequencing data concerning the phylogeny of numerous cleistothecial ascomycetes confirmed that the criterion of the production of closed ascomata without a predefined opening and with an irregular arrangement of the asci at the centrum is of little systematic value, as pointed out by different authors on the basis of morphological studies. 相似文献
8.
The geographic range and bloom frequency of the toxic dinoflagellate Alexandrium minutum and other members of the A. minutum group have been increasing over the past few decades. Some of these species are responsible for paralytic shellfish poisoning (PSP) outbreaks throughout the world. The origins of new toxic populations found in previously unaffected areas are typically not known due to a lack of reliable plankton records with sound species identifications and to the lack of a global genetic database. This paper provides the first comprehensive study of minutum-group morphology and phylogeny on a global scale, including 45 isolates from northern Europe, the Mediterranean, Asia, Australia and New Zealand.Neither the morphospecies Alexandrium lusitanicum nor A. angustitabulatum was recoverable morphologically, due to large variation within and among all minutum-group clonal strains in characters previously used to distinguish these species: the length:width of the anterior sulcal plate, shape of the 1′ plate, connection between the 1′ plate and the apical pore complex, and the presence of a ventral pore. DNA sequence data from the D1 to D2 region of the LSU rDNA also fail to recognize these species. Therefore, we recommend that all isolates previously designated as A. lusitanicum or A. angustitabulatum be redesignated as A. minutum. A. tamutum, A. insuetum, and A. andersonii are clearly different from A. minutum on the basis of both genetic and morphological data.A. minutum strains from Europe and Australia are closely related to one another, which may indicate an introduction from Europe to Australia given the long history of PSP in Europe and its recent occurrence in Australia. A minutum from New Zealand and Taiwan form a separate phylogenetic group. Most strains of A. minutum fit into one of these two groups, although there are a few outlying strains that merit further study and may represent new species. The results of this paper have greatly improved our ability to track the spread of A. minutum species and to understand the evolutionary relationships within the A. minutum group by correcting inaccurate taxonomy and providing a global genetic database. 相似文献
9.
Phylogenetic analyses based on morphology placeAnaxagorea and other taxa with granular monosulcate pollen, as in otherMagnoliales, at the base ofAnnonaceae. Taxa with columellar tetrads, granular tetrads, and inaperturate monads form a derived clade. To test the systematic importance of palynology, we analyzed the data set with pollen characters removed. The result was lower resolution and a different rooting of the family, betweenUvariopsis and other groups with columellar tetrads.Anaxagorea and other monosulcates are higher in the tree, implying that granular monosulcate pollen, laminar stamens, and irregular endosperm ruminations are reversals. This rooting is highly unparsimonious when pollen characters are included, and only weakly supported over theAnaxagorea rooting when pollen is excluded. Together with preliminary molecular analyses, these experiments confirm the special value of palynology in systematics ofAnnonaceae.This paper is dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday 相似文献
10.
Carolina M. van Zuilen Jifke Koek-Noorman Paul J. M. Maas 《Plant Systematics and Evolution》1995,194(3-4):173-188
In this paper we present a phylogeny based on a study of the general morphology of 61 of the ca. 80 species ofDuguetia. Analyses were performed with PAUP. The resulting phylogeny is compared with the classification ofDuguetia as suggested byFries (1934, 1937, 1939, 1959). The results are partly corresponding withFries's classification. SectionAlcmene includingD. rionegrensis, and sects.Geanthemum, Synsepalantha, andCalothrix withoutD. uniflora, are upheld by this analysis. It is concluded that sect.Xylopipetalum should be united with sect.Duguetia. Before other taxonomic decisions at the section level can be made, more solid data must be available. Most dissimilarities found are considered to be not strong enough to propose alterations.Studies inAnnonaceae XXIII. For 22nd part seeZuilen & Maas (1994). 相似文献
11.
The neotropical genusExostema comprises 25 species of trees and shrubs, ranging in distribution from Bolivia to Mexico and throughout the West Indies, with most species endemic to the Greater Antilles. Infrageneric relationships and species-level patterns of evolution were investigated in phylogenetic analyses using morphological, molecular, and combined data sets. All data sets resolved three main species groups which correspond to the three sections recognized byMcDowell (1996). However, the analyses of ITS sequence data placed the two South American species basal to the three main clades. Otherwise, the morphological and molecular data are highly compatible, and produce a more robust yet consistent phylogeny in the combined data analysis. Morphological evolution inExostema involves many specializations for xeric habitats, reflecting repeated ecological shifts from moist forest to exposed, seasonally dry environments during the diversification of the genus. Both moth and bee pollination syndromes are found inExostema, and shifts in pollination ecology appear pivotal to the differentiation of the three sections. Biogeographically,Exostema likely originated in South America and migrated via Central America to the Greater Antilles, where the morphological diversification and speciation are most extensive. 相似文献
12.
Heterokonts are evolutionarily important as the most nutritionally diverse eukaryote supergroup and the most species-rich
branch of the eukaryotic kingdom Chromista. Ancestrally photosynthetic/phagotrophic algae (mixotrophs), they include several
ecologically important purely heterotrophic lineages, all grossly understudied phylogenetically and of uncertain relationships.
We sequenced 18S rRNA genes from 14 phagotrophic non-photosynthetic heterokonts and a probable Ochromonas, performed phylogenetic analysis of 210–430 Heterokonta, and revised higher classification of Heterokonta and its three phyla:
the predominantly photosynthetic Ochrophyta; the non-photosynthetic Pseudofungi; and Bigyra (now comprising subphyla Opalozoa,
Bicoecia, Sagenista). The deepest heterokont divergence is apparently between Bigyra, as revised here, and Ochrophyta/Pseudofungi.
We found a third universal heterokont signature sequence, and deduce three independent losses of ciliary hairs, several of
1-2 cilia, 10 of photosynthesis, but perhaps only two plastid losses. In Ochrophyta, heterotrophic Oikomonas is sister to the photosynthetic Chrysamoeba, whilst the abundant freshwater predator Spumella is biphyletic; neither clade is specifically related to Paraphysomonas, indicating four losses of photosynthesis by chrysomonads. Sister to Chrysomonadea (Chrysophyceae) is Picophagea cl. nov.
(Picophagus, Chlamydomyxa). The diatom-parasite Pirsonia belongs in Pseudofungi. Heliozoan-like actinophryids (e.g. Actinosphaerium) are Opalozoa, not related to pedinellids within Hypogyristea cl. nov. of Ochrophyta as once thought. The zooflagellate class
Bicoecea (perhaps the ancestral phenotype of Bigyra) is unexpectedly diverse and a major focus of our study. We describe four
new biciliate bicoecean genera and five new species: Nerada mexicana, Labromonas fenchelii (=Pseudobodo tremulans sensu Fenchel), Boroka karpovii (=P. tremulans sensu Karpov), Anoeca atlantica and Cafeteria mylnikovii; several cultures were previously misidentified as Pseudobodo tremulans. Nerada and the uniciliate Paramonas are related to Siluania and Adriamonas; this clade (Pseudodendromonadales emend.) is probably sister to Bicosoeca. Genetically diverse Caecitellus is probably related to Anoeca, Symbiomonas and Cafeteria (collectively Anoecales emend.). Boroka is sister to Pseudodendromonadales/Bicoecales/Anoecales. Placidiales are probably divergent bicoeceans (the GenBank Placidia sequence is a basidiomycete/heterokont chimaera). Two GenBank ‘opalinid’ sequences are fungal; Pseudopirsonia is cercozoan; two previous GenBank ‘Caecitellus’ sequences are Adriamonas.
Electronic Supplementary Material Electronic Supplementary material is available for this article at
and accessible for authorised users.
[Reviewing Editior: Patnck J. Keeling] 相似文献
13.
Michio Wakabayashi 《Journal of plant research》1992,105(3):485-502
The embryo sac formation, endosperm formation, and embryo development in all species of JapaneseMitella andM. diphylla of North America were studied. Monosporic 8-nucleate embryo sac formation of thePolygonum type was found in all the species. In endosperm formation, the Cellular type was found in all species of sect.Mitellaria, and the Helobial type inM. nuda, M. diphylla, andM. integripetala. The Helobial type inM. integripetala was somewhat aberrant and approximated to the Cellular type. In embryo development, three types were distinguishable in sect.Mitellaria: Type A (most of the species), Type B (M. acerina) and Type C (M. pauciflora andM. furusei var.furusei). Type B is an intermediate type between A and C.Mitella integripetala also shows Type A, and the types ofM. nuda andM. diphylla are similar to Type A, except for the shape of suspensor. From outgroup comparison, Type A is suggested to be primitive and Type C to be most derivative in sect.Mitellaria. The affinity of some species in sect.Mitellaria is discussed from the embryogenic data obtained. 相似文献
14.
The pore-systems of 17 extant species of Loxoconcha around Japan were studied in order to understand their phylogeny and evolution. The phylogeny was estimated by two steps.
First, the 17 species were divided into two groups, Group A (12 species) and Group B (five species) by Pore pattern Below
Eye tubercle (PBE) analysis. Then, intragroup relationships were estimated by Differentiation of Distributional pattern of
Pore-system (DDP) analysis. PBE analysis reveals that species of Groups A and B have on average different ecological preferences.
Species of Group A, which appeared in the late Pliocene, are more diverse, have both phytal and bottom-dwelling modes of life,
possess fewer pore-systems in the ventral area, and inhabit normal marine environments. Species of Group B, whose oldest fossil
record is the lower Miocene, are less diverse, have only bottom-dwelling species, possess more pore-systems in the ventral
area, and tend to inhabit brackish water environments. The results of this study suggest that the differences in ecology may
have had an impact on the late Cenozoic diversification around Japan. The primary invasion of Group B occurred before the
lower Miocene,with no subsequent diversification. Group A invaded after the late Pliocene and immediately diversified, which
created the present abundance of Loxoconcha species around Japan in both species diversity and variety of modes of life. 相似文献
15.
J. P. W. Young 《Plant and Soil》1996,186(1):45-52
Rhizobia are bacteria that form nitrogen-fixing nodules on the roots, or occasionally the shoots, of legumes. There are currently more than a dozen validly named species, but the true number of species is probably orders of magnitude higher. The named species are listed and briefly discussed. Sequences of the small subunit ribosomal RNA (SSU or 16S rRNA) support the well-established subdivision of rhizobia into three genera: Rhizobium, Bradyrhizobium, and Azorhizobium. These all lie within the alpha subdivision of the Proteobacteria, but on quite distinct branches, each of which also includes many bacterial species that are not rhizobia. It has been clear for several years that Rhizobium, on this definition, is still too broad and is polyphyletic: there are many non-rhizobia within this radiation. Recently, therefore, it has been suggested that this genus should be split into four genera, namely Rhizobium (R. leguminosarum, R. tropici, R. etli), Sinorhizobium (S. fredii, S. meliloti, S. teranga, S. saheli), Mesorhizobium (M. loti, M. huakuii, M ciceri, M. tianshanense, M. mediterraneum), and a fourth, unnamed, genus for the current R. galegae. The evidence and pros and cons are reviewed. 相似文献
16.
Yoshitaka Ono 《Mycoscience》2006,47(3):145-151
Ochropsora ariae was found to host-alternate between Anemone pseudo-altaica and Aruncus dioicus var. tenuifolius and Ochropsora nambuana between Anemone flaccida and Elaeagnus multiflora var. hortensis in Japan. Both species produced a sessile, thin-walled, cylindrical probasidium (teliospore), which turned into a four-celled metabasidium by continuous apical elongation of the probasidium. Several probasidia of O. nambuana were produced from a basal basidiogenous cell in a sorus hymenium. Life cycle and probasidium/metabasidium morphology showed the taxonomic identity of Ceraceopsora elaeagni with O. nambuana. Developmental morphology of the basidium found in the two Ochropsora species raised a question against the taxonomic separation of Ochropsora and Aplopsora. 相似文献
17.
Phylogeny of Early Cretaceous spatangoids (Echinodermata: Echinoidea) and taxonomic implications 总被引:1,自引:0,他引:1
Loïc Villier Didier Néraudeau Bernard Clavel Christian Neumann & Bruno David 《Palaeontology》2004,47(2):265-292
A phylogenetic analysis of 36 species provides a test for the taxonomy and the history of Early Cretaceous spatangoids. Most taxonomic units from genera to suborders are consistent with the proposed phylogenetic framework. We retain Hemiasterina, Micrasterina, Hemiasteridae, Schizasteridae, Hemiaster , Heteraster , Mecaster , and Periaster as original monophyletic groups. However, all of these clades originate without the classical apomorphies normally ascribed to them. We suggest a revision of their diagnoses and of the generic attributions of basal species. Some ill-defined, 'primitive', and paraphyletic taxa are recognised: Toxaster , Epiaster , Palhemiaster , and Toxasteridae. Even if they do not have phylogenetic meaning, they are retained here, pending a more complete revision. 相似文献
18.
Nutlet sculpturing of 22 taxa ofScutellaria sect.Resinosa, representing 18 of its 19 species, and the monotypic genusSalazaria was studied by scanning electron microscopy (SEM). The nutlets of sect.Resinosa, while remarkably variable among themselves, differed from hypothetically closely related sections in lacking circumferential banding and sessile glands. Species could be grouped by surface sculpturing into seemingly meaningful phenetic clusters.Scutellaria potosina var.platyphylla was sufficiently distinct micromorphically so as to be elevated to specific status asScutellaria platyphylla comb. and stat. nov. The significance of nutlet microcharacters within sect.Resinosa is discussed, especially as compared to closely related sections. The genusSalazaria had nutlet sculpturing quite different from all taxa belonging to sect.Resinosa. 相似文献
19.
A cladistic analysis of the West Palaearctic Scopaeina Mulsant & Rey, 1878 (Coleoptera, Staphylinidae: Paederinae) is presented along with bionomic and biogeographic information. A total of 76 morphological characters were coded for the 88 currently known West Palaearctic species, except for S. bifossicapitata (Outerelo & Oromi, 1987). Results show that Scopaeina comprises two well-supported monophyletic groups in the West Palaearctic, Micranops Cameron, 1913 and Scopaeus Erichson, 1840, which are considered to represent distinct genera. Phylogenetic relationships to Orus Casey, 1884, distributed in North and South America, are briefly discussed. Whereas Micranops is only represented by M. pilicornis (Baudi, 1869) in the region under study, 87 species of Scopaeus are currently known from the West Palaearctic. Within Scopaeus, the cladistic analysis yielded many well-supported monophyletic species groups, most of which are restricted to the West Palaearctic. However, except for Hyperscopaeus Coiffait, 1984, they are not in agreement with the widely used subgeneric concept sensu Coiffait (1952–1984). The following polyphyletic subgenera are consequently synonymized: Alloscopaeus Coiffait, 1968, Anomoscopaeus Coiffait, 1968, Geoscopaeus Coiffait, 1960, and Hyposcopaeus Coiffait, 1960 synn. n. = Scopaeus Erichson, 1840. Nivorus Herman, 1965, and Microscopaeus Coiffait, 1981 synn. n. = Micranops Cameron, 1913. The monotypical genus Coecoscopaeus Coiffait, 1984, established for C. coecus (Peyerimhoff, 1906), is excluded from Scopaeina. Scopaeus mitratus perroti Ochs, 1953 is raised to species rank, and S. nigellus Wollaston, 1864, formerly a synonym of S. minimus Erichson, 1939, is revalidated. Finally, we present a catalogue of species and synonyms of West Palaearctic Scopaeina along with distributional data and five new synonymies of species group names: S. bordei Peyerimhoff, 1914 syn. n. = S. portai Luze, 1910; S. tassiliensis Jarrige, 1958, S. mauretanicus Coiffait, 1960 synn. n. = S. crassipes Wollaston, 1867; S. saoudiensis Coiffait, 1981 = S. sinaicus Coiffait, 1970; S. mateui Coiffait, 1953 syn. n. = S. didymus Erichson, 1840. A lectotype is designated for S. didymus Erichson, 1840.See also Electronic Supplement (Parts 13) at http://www.senckenberg.de/odes/02-02.htm 相似文献
20.
Robledo M Velázquez E Ramírez-Bahena MH García-Fraile P Pérez-Alonso A Rivas R Martínez-Molina E Mateos PF 《Systematic and applied microbiology》2011,34(6):393-399
The celC gene codifies for a cellulase that fulfils a very significant role in the infection process of clover by Rhizobium leguminosarum. This gene is located in the celABC operon present in the chromosome of strains representing R. leguminosarum, Rhizobium etli and Rhizobium radiobacter whose genomes have been completely sequenced. Nevertheless, the existence of this gene in other species of the genus Rhizobium had not been investigated to date. In this study, the celC gene was analysed for the first time in several species of this genus isolated from legume nodules and plant tumours, in order to compare the celC phylogeny to those of other chromosomal and plasmidic genes. The results obtained showed that phylogenies of celC and chromosomal genes, such as rrs, recA and atpD, were completely congruent, whereas no relation was found with symbiotic or virulence genes. Therefore, the suitability and usefulness of the celC gene to differentiate species of the genus Rhizobium, especially those with closely related rrs genes, was highlighted. Consequently, the taxonomic status of several strains of the genus Rhizobium with completely sequenced genomes is also discussed. 相似文献