Ontogeny and phylogeny of Metaurostylopsis cheni sp. n. (Protozoa,Ciliophora), with estimating the systematic position of Metaurostylopsis

Chen, X., Huang, J. & Song, W. (2010). Ontogeny and phylogeny of Metaurostylopsis cheni sp. n. (Protozoa, Ciliophora), with estimating the systematic position of Metaurostylopsis. —Zoologica Scripta, 40, 99–111. The ciliate genus Metaurostylopsis seems to be a highly divergent marine‐habiting group, of which neither systematic position nor the variation of their ontogeny has been critically checked. In the present work, the morphology and morphogenesis during asexual division of a new form, Metaurostylopsis cheni sp. n., isolated from the Yellow Sea, China, were investigated and comparison among known congeners was performed. The new species has two types of cortical granules, the larger ones of which are flattened and oval or circular in outline with a longitudinal groove, yellow–green in colour, and arranged along the cirral rows and dorsal kineties, whereas the smaller ones are colourless or grayish and sparsely distributed. The main morphogenetic features are: (i) the entire parental ciliature, including the old oral apparatus, is renewed, (ii) the oral primordium of the proter originates de novo and beneath the surface of the buccal cavity, that is, sub‐apokinetally, (iii) the anlagen of the marginal rows and of the dorsal kineties are formed intrakinetally and (iv) fusion of the macronuclear nodules results in an irregular mass with only few branches. The small subunit ribosomal RNA (SSU rRNA) gene of M. cheni was sequenced. Phylogenetic analysis based on SSU rRNA gene sequence data shows that M. cheni clusters with all other Metaurostylopsis spp. sequenced to date indicating that the genus is monophyletic and is probably closely related to the Apokeronopsis–Thigmokeronopsis‐group, within the order Urostylida.     

Morphology and infraciliature of two new marine urostylid ciliates: Metaurostylopsis struederkypkeae n. sp. and Thigmokeronopsis stoecki n. sp. (Ciliophora, Hypotrichida) from China

ABSTRACT. The morphology and infraciliature of two new marine urostylid ciliates, Metaurostylopsis struederkypkeae n. sp. and Thigmokeronopsis stoecki n. sp., collected from the coastal waters off Qingdao (Tsingtao), China, have been investigated. Metaurostylopsis struederkypkeae n. sp. is characterized by the slender body shape, small size, rose-reddish cell colour, and having two kinds of pigment-like granules. The larger pigment-like granules are yellow–green or grass-green in colour, oval in shape, and flattened, whereas the smaller ones are wine-reddish. Infraciliature and nuclear apparatus are similar to the well-known Metaurostylopsis marina. Thigmokeronopsis stoecki n. sp. is characterized by its large size with dark brown cell colour and grass-green cortical granules, which are large, blood-cell shaped, and sparsely distributed. The thigmotactic ciliature is conspicuous: 11–14 rows of densely arranged cirri occupy the most postoral area. Keys are provided for all the known species in both genera.     

Ontogenesis and molecular phylogeny of a new marine urostylid ciliate, Anteholosticha petzi n. sp. (Ciliophora, Urostylida)

A new urostylid ciliate, Anteholosticha petzi n. sp., isolated from the northern China seas, was studied using live observation and protargol impregnation. It differs from all the congeners mainly in the highly flexible and variable body shape, its red-brown to brick-red colour, and the possession of three types of cortical granules. Analysis of morphometric and molecular data confirm the validity of A. petzi as a distinct species. Anteholosticha petzi n. sp. is characterized as follows: by having 3 frontal, 1 buccal, 2 frontoterminal, 2 pretransverse, and 8-11 transverse cirri; a midventral row that comprises 10-16 cirral pairs and extends ca. 60% of cell length; and 3 bipolar dorsal kineties. Ontogenesis is similar to that in Anteholosticha warreni except for the formation of the oral primordium and is characterized by: (1) the parental adoral membranelles are completely renewed and the oral primordium is formed de novo; and (2) the anlagen for the frontal-ventral-transverse cirri are formed as primary primordia. The small subunit rRNA gene sequence of A. petzi n. sp. was also compared with that of its congeners with the sequence differences ranging from 0.39% to 8.62%. Phylogenetic trees based on the SSU rRNA gene sequence were constructed, indicating the nonmonophyly of the genus Anteholosticha, as supported by the approximately unbiased test.     

Morphology and small subunit (SSU) rRNA gene sequence of the new brackish water ciliate Neobakuella flava n. g., n. sp. (Ciliophora, Spirotricha, Bakuellidae) and SSU rRNA gene sequences of six additional hypotrichs from Korea

The morphology and the small subunit (SSU) rRNA gene sequence of the hypotrich Neobakuella flava n. g., n. sp. from the estuary of the Taehwagang River (Ulsan, South Korea) were investigated. The three frontal cirri, the composition of the midventral complex of cirral pairs and rows, and the simple dorsal kinety pattern of three bipolar kineties assign it to the urostyloid taxon Bakuellidae. The increased number of buccal and parabuccal cirri, the presence of transverse cirri, and more than one left marginal row, as well as the lack of caudal cirri separate Neobakuella n. g. from the other bakuellids. Neobakuella flava n. sp. has many 0.3 μm sized green and/or yellow usually dark-green cortical granules and some sparsely distributed, 2 × 1 μm sized grass green with yellowish shimmer granules. The gene sequence data indicate a close relationship with Diaxonella and a distinct separation from the bakuellid Metaurostylopsis and parabirojimid Parabirojimia. The SSU rRNA gene sequences of four further urostyloids (i.e. Diaxonella pseudorubra, Anteholosticha monilata, Metaurostylopsis struederkypkeae, Pseudourostyla cristata) and two stylonychines (i.e. Sterkiella cavicola, Sterkiella histriomuscorum) from Korea were analyzed. Anteholosticha monilata, type of the genus, is clearly separated from the Holosticha clade, supporting the morphological separation from Holosticha. Sterkiella cavicola, type of Sterkiella, clusters within the stylonychines and is obviously closely related with S. histriomuscorum.     

Evolution of the order Urostylida (Protozoa, Ciliophora): new hypotheses based on multi-gene information and identification of localized incongruence

Previous systematic arrangement on the ciliate order Urostylida was mainly based on morphological data and only about 20% taxa were analyzed using molecular phylogenetic analyses. In the present investigation, 22 newly sequenced species for which alpha-tubulin, SSU rRNA genes or ITS1-5.8S-ITS2 region were sampled, refer to all families within the order. Following conclusions could be drawn: (1) the order Urostylida is not monophyletic, but a core group is always present; (2) among the family Urostylidae, six of 10 sequenced genera are rejected belonging to this family; (3) the genus Epiclintes is confirmed belonging to its own taxon; (4) the family Pseudokeronopsidae undoubtedly belongs to the core portion of urostylids; however, some or most of its members should be transferred to the family Urostylidae; (5) Bergeriellidae is confirmed to be a valid family; (6) the distinction of the taxon Acaudalia is not supported; (7) the morphology-based genus Anteholosticha is extremely polyphyletic; (8) ITS2 secondary structures of Pseudoamphisiella and Psammomitra are rather different from other urostylids; (9) partition addition bootstrap alteration (PABA) result shows that bootstrap values usually tend to increase as more gene partitions are included.     

Morphogenesis in the marine spirotrichous ciliate Apokeronopsis crassa (Claparède & Lachmann, 1858) n. comb. (Ciliophora: Stichotrichia), with the establishment of a new genus, Apokeronopsis n. g., and redefinition of the genus Thigmokeronopsis

Morphogenetic events during the division of the marine spirotrichous ciliate, Apokeronopsis crassa (Claparède & Lachmann 1858) n. comb. were investigated. Compared with members of the well-known genera Thigmokeronopsis, Uroleptopsis, and Pseudokeronopsis, A. crassa has one row of buccal cirri, high number of transverse cirri, clearly separated midventral rows, lacks thigmotactic cirri and a gap in adoral zone, its undulating membranes (UMs) anlage forms one cirrus and marginal rows and dorsal kineties form apokinetally during division. All these characteristics indicate that this organism represents a new taxon at the generic level, and hence a new genus is suggested, Apokeronopsis n. g. It is defined as thus: Pseudokeronopsidae with Pseudokeronopsis-like bicorona of frontal cirri and one marginal row on each side; one row of two or more buccal cirri in ordinary position; two midventral rows distinctly separated, hence of cirri that are not in a typical zig-zag pattern; high number of transverse cirri, caudal cirri absent, and frontoterminal cirri present; thigmotactic cirri absent, many macronuclear nodules fuse into many masses as well as marginal and dorsal kineties form apokinetally during morphogenesis. At the same time, the genus ThigmokeronopsisWicklow, 1981 is redefined, and one new combination, Apokeronopsis antarctica (Petz, 1995) n. comb. is proposed. The morphogenetic events of A. crassa are characterized as follows: (1) In the proter, the adoral zone of membranelles and UMs are completely renewed by the oral primordium. The UM anlage is formed apokinetally on the dorsal wall of the buccal cavity and is hence clearly separated from the frontoventral-transverse (FVT) cirral anlagen in the proter. (2) Frontoventral-transverse cirral anlagen are generated de novo in the outermost region of the cortex to the right of the old UMs. (3) A row of buccal cirri arises from FVT cirral streak I. (4) The marginal rows and dorsal kineties originate de novo in both dividers; no caudal cirri are formed. (5) The last FVT-streak contributes two frontoterminal cirri. (6) The many macronuclear nodules fuse into many masses (about 50 segments) during division, unlike a singular or branched mass as described in other urostylids.     

Morphology,Morphogenesis, and Molecular Phylogeny of Anteholosticha multicirrata n. sp. (Ciliophora,Spirotrichea) with a Note on Morphogenesis of A. pulchra (Kahl, 1932) Berger, 2003

Two marine urostylid ciliates, Anteholosticha multicirrata n. sp. and Anteholosticha pulchra (Kahl, 1932) Berger, 2003, were collected from South Korea. These species were identified based on morphology, morphogenesis, and SSU rRNA gene sequence comparison. Anteholosticha multicirrata n. sp. is characterized by the following features: body size 90–125 × 30–45 μm in vivo, shape slender to ellipsoidal in outline, with yellow‐greenish cortical granules distributed along and between dorsal kineties and cirri; single contractile vacuole positioned on left at mid‐body; three frontal, five to seven frontoterminal, one buccal, one to two pretransverse and four to six transverse cirri; three complete dorsal kineties; one left and one right marginal cirral row; about 117 macronuclear nodules; and three to four micronuclei observed during morphogenesis. In addition, based on the observations of morphogenesis, we found that A. pulchra has pretransverse cirri, which were not described in detail in previous studies. Nuclear small subunit ribosomal RNA (SSU rRNA) gene was used to analyse their phylogenetic relationship, and the gene tree supports that the genus Anteholosticha is a highly polyphyletic group.     

Morphology and infraciliature of three species of Metaurostylopsis (Ciliophora, Stichotrichia): M. songi n. sp., M. salina n. sp., and M. marina (Kahl 1932) from sediments, saline ponds, and coastal waters

Two new urostylid ciliates, Metaurostylopsis songi n. sp. and Metaurostylopsis salina n. sp. and Metaurostylopsis marina (Kahl 1932) are investigated using live observation and protargol impregnation. These species were isolated in Korea from intertidal sediments, saline ponds, and coastal waters. Metaurostylopsis songi is in vivo about 120 microm x 25 microm, has a slenderly ellipsoidal body, colorless cortical granules in rows on ventral and dorsal body sides, about 54 macronuclear nodules, 28-47 adoral membranelles, five frontal, two or three frontoterminal and six or seven transverse cirri, and 9-12 midventral cirral pairs followed posteriorly by 1-3 single cirri. In vivo M. salina is about 60 microm x 25 microm, has a pyriform body, colorless cortical granules irregularly arranged, about 45 macronuclear nodules, 18-23 adoral membranelles, three frontal, three to five frontoterminal and two to five transverse cirri, and four or five midventral cirral pairs followed posteriorly by five to seven single cirri. Both species have three marginal cirral rows on each body side and 3 long dorsal kineties. The Korean specimens of M. marina match the Chinese population in all main features. Metaurostylopsis songi differs from M. marina by the more slender body, the number of frontal cirri (invariably five vs. four), and the arrangement of cortical granules (in rows on dorsal and ventral cortex vs. only along dorsal kineties and anterior body margin). Metaurostylopsis salina differs from its congeners by the distinctly smaller size, the pyriform body shape, the scattered cortical granules (vs. in rows), and number of frontal cirri. It differs from M. marina also by the number of midventral cirral pairs (four or five vs. seven to 11).     

Re-evaluation on the diversity of the polyphyletic genus Metaurostylopsis (Ciliophora, Hypotricha): ontogenetic, morphologic, and molecular data suggest the establishment of a new genus Apourostylopsis n. g

The urostylid genus Metaurostylopsis Song et al., 2001 was considered to be a well-outlined taxon. Nevertheless, recent evidence, including morphological, ontogenetic, and molecular information, have consistently revealed conflicts among congeners, regarding their systematic relationships, ciliature patterns, and origins of ciliary organelles. In the present work, the morphogenetic and morphogenetic features were re-checked and compared, and the phylogeny of nominal species was analysed based on information inferred from the small subunit ribosomal RNA (SS rRNA) gene sequence. In addition, the binary divisional process in a new isolate of Metaurostylopsis struederkypkeae Shao et al., 2008 is described. All results obtained reveal that the genus is a polyphyletic assemblage whose nominal congeners fall into three clades within the core Urostylida, based on SS rRNA gene sequences. These three clades not match the groups inferred from morphological/morphogenetical evidences. Some conflicting data from molecular and ontogenetic studies also indicate that single-gene information might not be consistently reliable in detecting the phylogenetic relationships among closely related groups and comprehensive multi-gene analyses are necessary to give a more exact evaluation for this divergent assemblage. According to our new understandings, five forms are confirmed to be true Metaurostylopsis. The morphotype Metaurostylopsis sinica Shao et al., 2008 should be excluded from the genus and represents a distinct type, and, thus, a new genus Apourostylopsis n. g. with it as the type specie, i.e. Apourostylopsis sinica (Shao et al., 2008) n. comb.     

Anteholosticha foissneri n. sp., a marine hypotrich ciliate (Ciliophora: Spirotrichea) from Vietnam: Morphology,morphogenesis, and molecular phylogeny

In a study of marine ciliate diversity, we collected an Anteholosticha monilata-like population from Vietnam. To identify this population, we analyzed its morphology, some morphogenetic stages, and molecular phylogeny. Based on these data, we conclude that the Vietnamese population is new to science. Anteholosticha foissneri n. sp. resembles Anteholosticha monilata-like species considering (1) the number and arrangement of macronuclear nodules and micronuclei; (2) the presence of cortical granules; and (3) the saline habitat. However, the new species can be easily distinguished from these species by the arrangement, color, and shape of the cortical granules. The divisional morphogenesis commences with the de novo proliferation of basal bodies as a single longitudinal patch left of the posteriormost midventral cirral pair. This character state has not been reported before in Anteholosticha (based on check of the available data) and probably reflects a distinct clade within the nuclear small subunit ribosomal RNA gene tree.     

Molecular Phylogeny and Taxonomy of Two Novel Brackish Water Hypotrich Ciliates,with the Establishment of a New Genus,Antiokeronopsis gen. n. (Ciliophora,Hypotrichia)

Two novel brackish water urostyloid ciliates, Anteholosticha paramanca sp. n. and Antiokeronopsis flava gen. n., sp. n., isolated from the Shenzhen Mangrove Nature Protection Area on the coast of the South China Sea, were investigated using live observation and protargol impregnation techniques. Anteholosticha paramanca sp. n. is characterized by its spherical yellowish cortical granules arranged in lines, shortened midventral complex and three transverse cirri. Morphogenesis is similar to that in Anteholosticha manca. The new genus Antiokeronopsis is diagnosed by having a continuous adoral zone of membranelles, frontal cirri arranged in a bicorona, midventral complex composed of midventral pairs only, one marginal cirral row on each side, the presence of frontoterminal and transverse cirri, and the lack of buccal and caudal cirri. The type species A. flava sp. n. is characterized by its elongated body shape, brown to yellowish body color and two types of cortical granules. Small subunit ribosomal RNA gene sequence data justify the classification of both species. Phylogenetic analyses indicate that A. paramanca clusters with Bakuella subtropica within a clade that includes two other Anteholosticha species, while Antiokeronopsis groups within the core urostylids and is most closely related to the well‐known genera Pseudokeronopsis and Uroleptopsis.     

New contributions to the taxonomy of urostylid ciliates (Ciliophora,Hypotrichia), with establishment of a new genus and new species

Hypotrichia, one of the most complex and highly differentiated groups in Ciliophora, has been the object of extensive studies, especially in recent years. Nevertheless, methodological difficulties and insufficient faunistic studies have limited our understanding of their biodiversity and phylogeny. In this study, one novel urostylid ciliate, Pseudoholosticha zhaoi nov. gen., nov. spec. and two populations of Anteholosticha monilata (Kahl, 1928) Berger, 2003, type species of the latter genus, are studied using an integrative approach (live observation, protargol impregnation, scanning electron microscopy, and phylogenetic analysis) to provide further insights into the diversity, classification, and phylogeny of this group of ciliates. Pseudoholosticha nov. gen. can be separated from other morphologically similar genera mainly by the absence of buccal and caudal cirri. A key to 12 morphologically similar genera and illustrations of their cirral patterns are provided. The validation of the new genus and new species is supported by both morphological and phylogenetic analyses. The first 18S rRNA gene sequence of A. monilata, with detailed morphological data, provided a reliable clarification of A. monilata populations and corroborated the phylogenetic position of the type species of the polyphyletic genus Anteholosticha.     

Morphology and morphogenesis of a new marine ciliate, Apokeronopsis bergeri nov. spec. (Ciliophora, Hypotrichida), from the Yellow Sea, China

The morphology and morphogenesis of a new marine hypotrich ciliate, Apokeronopsis bergeri nov. spec., collected from mussel-farming waters near Qingdao, China, are described from living and protargol-impregnated specimens. This ciliate has characteristics that place it in the family Pseudokeronopsidae, namely, two long rows of frontal cirri (bicorona), which are continuous with the long midventral rows, and a single row of marginal cirri on each side of the body. It shares with its only congener, Apokeronopsis crassa, the long rows of buccal and transverse cirri and the wide spacing between the midventral rows of cirri. These characters separate the genus Apokeronopsis from Pseudokeronopsis, which has a single buccal cirrus, fewer transverse cirri and midventral rows of cirri arranged in a typical zig-zag pattern. A. bergeri differs from A. crassa in its shape, colour and in the numbers of membranelles and transverse cirri. Although morphogenesis in A. bergeri is similar to that of A. crassa in most respects, the mode of formation of the buccal cirri is slightly different. The close relationship of A. bergeri with A. crassa, and the more distant relationship with three Pseudokeronopsis species, is supported by a comparison of the sequences of their ITS1-5.8S-ITS2 rDNA regions.     

Recognition of Morganella subspecies, with proposal of Morganella morganii subsp. morganii subsp. nov. and Morganella morganii subsp. sibonii subsp. nov.

The genus name Morganella was established within the family Enterobacteriaceae in 1978. Morganella morganii is the only species described thus far within this genus, and the name M. morganii has been accepted by usage in the scientific community for strains previously known as Proteus morganii. M. morganii isolates differ in their abilities to ferment trehalose and exhibit variable lysine and ornithine decarboxylase patterns, emphasizing the phenotypic heterogeneity within this species. Previous genetic studies failed to reveal separate entities within the genus Morganella. We observed some trehalose-fermenting strains with different lysine and ornithine decarboxylase patterns. Two strains were lysine and ornithine positive, 3 were lysine positive and ornithine negative, and 29 were lysine negative and ornithine positive. These strains and 25 non-trehalose-fermenting strains with different lysine and ornithine decarboxylase patterns were investigated. DNA-DNA hybridization studies and phenotypic characterizations revealed that M. morganii can be separated into three DNA relatedness groups and seven biogroups. Strains from DNA relatedness group 1 were trehalose negative, and strains from DNA relatedness groups 2 and 3 were trehalose positive. One biogroup from DNA relatedness group 2 was phenotypically indistinguishable from DNA relatedness group 3. On the basis of these studies, we propose that M. morganii be subdivided into M. morganii subsp. morganii (type strain ATCC 25830) containing biogroups A, B, C, and D (DNA relatedness group 1) and M. morganii subsp. sibonii (type strain 8103-85; = ATCC 49948) containing biogroups E, F, and G (DNA relatedness groups 2 and 3).     

Phylogeny and character evolution in Medicago (Leguminosae): Evidence from analyses of plastid trnK/matK and nuclear GA3ox1 sequences

? Premise of the study: The genus Medicago, with about 87 species, includes the model legume species M. truncatula, and a number of important forage species such as M. sativa (alfalfa), M. scutellata (snail medic), and M. lupulina (black medic). Relationships within the genus are not yet sufficiently resolved, contributing to difficulty in understanding the evolution of a number of distinguishing characteristics such as aneuploidy and polyploidy, life history, structure of cotyledons, and number of seeds per fruit. ? Methods: Phylogenetic relationships of 70-73 species of Medicago and its sister genus Trigonella (including Melilotus) were reconstructed from nucleotide sequences of the plastid trnK/matK region and the nuclear-encoded GA3ox1 gene (gibberellin 3-β-hydroxylase) using maximum parsimony and Bayesian inference methods. ? Key results: Our results support certain currently recognized taxonomic groups, e.g., sect. Medicago (with M. sativa) and sect. Buceras. However, other strongly supported clades-the "reduced subsection Leptospireae clade" that includes M. lupulina, the "polymorpha clade" that includes M. murex and M. polymorpha and the "subsection Pachyspireae clade" that includes M. truncatula-each of which includes species presently in different subsections of sect. Spirocarpos, contradict the current classification. ? Conclusions: These results support the hypothesis that some characters considered important in existing taxonomies, for example, single-seeded fruits that have arisen more than once in both Medicago and Trigonella, are indeed homoplastic. Others, such as the 2n = 14 chromosome number, have also arisen independently within the genus. In addition, we demonstrate support for the utility of GA3ox1 sequences for phylogenetic analysis among and within closely related genera of legumes.     

Insights into the phylogenetic and taxonomy of philasterid ciliates (Protozoa, Ciliophora, Scuticociliatia) based on analyses of multiple molecular markers

Scuticociliates are a rich assemblage of species with mostly unresolved phylogenetic relationships, especially in the order Philasterida. In the present work, 48 new sequences for three linked genes are characterized and phylogenetic trees are constructed to assess the inter- and intra-generic relationships of philasterids. Results reveal the following: (1) the combined three-gene tree provides more resolution in nodes than in the SSU-rDNA topologies; (2) the family Orchitophryidae is non-monophyletic as it is split into two parts and Paranophrys magna, Metanophrys sp. and Metanophrys sinensis are designated incertae sedis at the familial level; (3) Uronematidae is non-monophyletic and Homalogastra setosa is designated incertae sedis; (4) Parauronematidae becomes a junior synonym of Uronematidae and the clade containing A. haemophila, Miamiensis avidus, and Glauconema trihymene might stand for a new family; (5) Parauronema being a junior synonym of Uronema is supported and P. longum should be removed from the genus Parauronema; (6) Uronema is not monophyletic and molecular analyses reveal that Uronema sp. QD shares a more recent common ancestor with Uronemella species than with other Uronema species; (7) Metanophrys is polyphyletic; (8) multiple samples of two highly controversial species, viz., Mesanophrys pugettensis and M. chesapeakensis have identical ITS1-5.8S-ITS2 region sequence and we propose they should be synonymous with M. carcini, and (9) there may be cryptic species in M. carcini and M. avidus.     

A revised classification of the genus Matrona Selys, 1853 using molecular and morphological methods (Odonata: Calopterygidae)

An extensive review of the genus Matrona is presented based on mitochondrial (COI) and nuclear (ITS) sequences from 150 samples which cover all the known taxa of this genus. The separation of two main clades (oreades group: M. oreades, M. corephaea and M. taoi; basilaris group: M. basilaris, M. nigripectus, M. cyanoptera, M. japonica and M. annina) is strongly supported. The classification of all traditional recognized species is confirmed. The Hainan population separates very well from mainland M. basilaris populations, which is also confirmed by geometric morphometric analysis of wing shape. Given the implications of the molecular analysis the genus Matrona is grouped into two subgenera: subgen. Matrona (type species M. basilaris) and D ivortia subgen. nov. (type species M. oreades). A new species, M . ( M .) mazu sp. nov. , from Hainan is described. Brief taxonomic notes on the nine recognized species of the genus are given. Lectotype designations of M. basilaris and M. nigripectus are published. © 2015 The Linnean Society of London     

基于ITS序列探讨杜鹃属的亚属和组间系统关系

首次报道了15种杜鹃属(Rhododendron)植物、1种杜香属(Ledum)植物和Cassiope fastigiata的内转录间隔区(ITS) (包括5.8S)序列.加上从GenBank下载的13种杜鹃属植物和Bajiaria racemosa的ITS序列,以C. fastigiata和B. racemosa为外类群,用最大简约法对杜鹃属的亚属和组间的系统关系进行了分析.结果表明: 1)杜鹃属是一个单系类群,叶状苞亚属为杜鹃属的基部类群; 2)杜香属确应归并到杜鹃属中,且与有鳞杜鹃亚属有较近的亲缘关系; 3)有鳞杜鹃亚属和杜香构成一个单系分支,该分支是其余无鳞杜鹃花的姐妹群; 4)由无鳞杜鹃花组成的一个分支的内部支持率较低,其中常绿杜鹃亚属和映山红亚属均为内部支持率很高的单系类群,而羊踯躅亚属和马银花亚属均为多系类群; 5)在马银花亚属中,长蕊杜鹃组和马银花组均分别得到强烈支持,马银花组与异蕊杜鹃亚属可能构成姐妹群关系,异蕊杜鹃亚属和马银花组组成的一个分支可能与映山红亚属构成姐妹群关系.     

用matK序列分析探讨木兰属植物的系统发育关系

用木兰科Magnoliaceae 57种植物的matK基因序列构建了该科的系统发育分支图。结果表明: (1)木兰属Magnolia L.是一个因为性状的趋同演化而建立的多系类群; (2)木兰亚属subgen. Magnolia和玉兰亚属subgen. Yulania (Spach) Reichenb.亲缘关系较远, 支持将后者从该属中分出建立玉兰属Yulania Spach, 木兰亚属作为木兰属保留; (3)木兰亚属的sect. Splendentes Dandy ex Vazquez组与皱种组sect. Rytidospermum Spach的两个美洲种M. macrophylla Michaux和M. dealbata Zucc.亲缘关系较近, 荷花玉兰组sect. Theorhodon Spach与常绿组sect. Gwillimia DC.的亲缘关系较近; (4)盖裂木属Talauma Juss.可以成立, 而其分布于亚洲的Blumiana Blume组可归入木兰属; (5)拟单性木兰属Parakmeria Hu &; Cheng、华盖木属Manglietiastrum Law以及单性木兰属Kmeria (Pierre) Dandy形成一个单系群, 与玉兰亚属和含笑属Michelia L.的亲缘关系较近。花的着生位置不足以作为木兰科的分族依据, 含笑族Michelieae和木兰族Magnolieae的特征及其界定应做修改。将玉兰亚属从木兰属分出后, 木兰属与含笑属无性状交叉,成为两个区别明显的属。     

迷蛱蝶属及相关物种细胞色素b基因序列及其分子系统学研究

迷蛱蝶属Mimathyma隶属于蛱蝶科Nymphalidae闪蛱蝶亚科Apaturinae,该属所包含的种类复杂,其分类学地位存在争议.本文对迷蛱蝶属、闪蛱蝶属Apatura和带蛱蝶属Athyma7个种共19个个体的线粒体DNA细胞色素b基因部分序列进行测定分析,并以花斑螯蛱蝶Charaxes kahruba (Moore)作为外群用PAUP软件构建MP和NJ分子系统树.结果显示迷蛱蝶Mimathyma chevana(Moore)、夜迷蛱蝶Mimathyma nycteis(Ménétriès)、白斑迷蛱蝶Mimathyma schrenckii (Ménétriès)和环带迷蛱蝶Mimathyma ambica Kollar形成1个聚类簇,支持Moore将这4个种由闪蛱蝶属移出并建立迷蛱蝶属的观点.同时,尽管迷蛱蝶在形态上与该属其余3种相似,但研究发现聚类簇Ⅰ中夜迷蛱蝶、白斑迷蛱蝶和环带迷蛱蝶首先相聚,然后再与迷蛱蝶聚在一起,表明迷蛱蝶与这3种亲缘关系较远.此外,本文的研究结果还显示迷蛱蝶属与闪蛱蝶属关系密切,而与带蛱蝶属的关系较远.