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1.
The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.  相似文献   

2.
Parsimony analyses of the internal transcribed spacer regions of nuclear ribosomal DNA (ITS 1 & ITS 2) for 38 taxa sampled from the Phebalium group (Rutaceae: Boronieae) and two outgroups confirm that, with the exception of Phebalium sensu stricto and Rhadinothamnus, six of the currently recognised genera within the group are monophyletic. The data indicate that Phebaliums. str. is paraphyletic with respect to Microcybe, and Rhadinothamnus is paraphyletic with respect to Chorilaena. Rhadinothamnus and Chorilaena together are the sister group to Nematolepis. Drummondita, included as an outgroup taxon, clustered within the ingroup as sister to Muiriantha and related to Asterolasia.The phylogeny suggests that the evolution of major clades within a number of these genera (e.g. Phebalium) relates to vicariance events between eastern and south-western Australia. Leionema is an eastern genus, with the most basal taxon being the morphologically distinct Leionema ellipticum from northern Queensland. Leionema also includes one species from New Zealand, but this species (as with some others) proved difficult to sequence and its phylogenetic position remains unknown. Taxonomic changes at the generic level are recommended.The authors wish to thank Paul G.Wilson, PERTH, for advice and discussion, and Paul Forster, BRI, for collecting and providing material of Leionema ellipticum. The project was supported by a Melbourne University Postgraduate Award (to BM), the Australian Biological Resources Study (ABRS), Australian Systematic Botany Society and Wolf Den (Australia) Investments.  相似文献   

3.
4.
Trichoderma theobromicola and T. paucisporum spp. nov. are described. Trichoderma theobromicola was isolated as an endophyte from the trunk of a healthy cacao tree (Theobroma cacao, Malvaceae) in Amazonian Peru; it sporulates profusely on common mycological media. Trichoderma paucisporum is represented by two cultures that were obtained in Ecuador from cacao pods partially infected with frosty pod rot, Moniliophthora roreri; it sporulates sporadically and most cultures remain sterile on common media and autoclaved rice. It sporulates more reliably on synthetic low-nutrient agar (SNA) but produces few conidia. Trichoderma theobromicola was reintroduced into cacao seedlings through shoot inoculation and was recovered from stems but not from leaves, indicating that it is an endophytic species. Both produced a volatile/diffusable antibiotic that inhibited development of M. roreri in vitro and on-pod trials. Neither species demonstrated significant direct in vitro mycoparasitic activity against M. roreri.  相似文献   

5.
The hypothesis ofHenriques andFernandes that several Iberian species ofNarcissus (Amaryllidaceae) are tristylous is reconsidered. Contrary to the opinion ofBateman and most subsequent authors, we believe that the available evidence indicates that some populations ofN. triandrus andN. fernandesii, at least, are tristylous; other populations ofN. triandrus are distylous.Hugonia cf.penicillanthemum (Linaceae) from new Caledonia is distylous, but it remains possible that other species ofHugonia are tristylous. The disputed occurrence of heterostyly in S. African species ofBauhinia (Leguminosae),Cleome (Capparaceae) andAneilema (Commelinaceae), and inAgelaea (Connaraceae) is discussed.  相似文献   

6.
The fresh waters of the Mekong basin are inhabited by five species of the pufferfish genusTetraodon Linnaeus, 1758 (sensu lato): the widely distributedT. leiurus Bleeker, 1851; two previously described species endemic to the Mekong,T. baileyi Sontirat, 1989 andT. suvattii Sontirat & Soonthornsathit, 1985; one new species endemic to the Mekong basins.Tetraodon baileyi has now been collected numerous times but only in or near rapids;T. abei, T. barbatus andT. suvattii are often but not exclusively associated with rapids or at least swift flowing streams; whileT. leiurus is found in almost all habitats except rapids.Tetraodon abei andT. barbatus are closely related toT. leiurus, from which they differ most strikingly in coloration.Tetraodon survattii differs from all of the others in having a strongly upturned mouth and light and dark stripes or spots radiating outwards from the eye.Tetraodon baileyi, the most distinctive Mekong pufferfish, has head and body more or less extensively covered with dermal cirri and is entirely scaleless.  相似文献   

7.
New and old problems in the taxonomy of the Gelidiales (Rhodophyta)   总被引:1,自引:1,他引:0  
Santelices  Bernabé 《Hydrobiologia》1990,204(1):125-135
The order Gelidiales includes over 140 agar-producing taxa. Many species are taxonomically confused; the boundaries of one family and all but four genera recently have been contested, and the controversy over ordinal status has lasted for over 25 years. This study reviews recent developments in the taxonomy of the group and suggests future areas for studies. The order cannot be defined by a few exclusive characters, as intended in the past, but it shows a unique combination of characters. Additional studies on Gelidiella and Acanthopeltis seem advisable to clarify family limits. The segregation of Onikusa and Pterocladiastrum is doubtful. Only three of six characters discriminate Gelidium from Pterocladia. None allows complete generic segregation and all need variability studies. Analysis of nomenclatural types in the light of morphological variation would permit an understanding of species limits in Gelidium and Pterocladia. Similar studies are needed in Gelidiella and Ptilophora.  相似文献   

8.
The family Sordariaceae incorporates a number of fungi that are excellent model organisms for various biological, biochemical, ecological, genetic and evolutionary studies. To determine the evolutionary relationships within this group and their respective phylogenetic placements, multiple-gene sequences (partial nuclear 28S ribosomal DNA, nuclear ITS ribosomal DNA and partial nuclear β-tubulin) were analysed using maximum parsimony and Bayesian analyses. Analyses of different gene datasets were performed individually and then combined to generate phylogenies. We report that Sordariaceae, with the exclusion Apodus and Diplogelasinospora, is a monophyletic group. Apodus and Diplogelasinospora are related to Lasiosphaeriaceae. Multiple gene analyses suggest that the spore sheath is not a phylogenetically significant character to segregate Asordaria from Sordaria. Smooth-spored Sordaria species (including so-called Asordaria species) constitute a natural group. Asordaria is therefore congeneric with Sordaria. Anixiella species nested among Gelasinospora species, providing further evidence that non-ostiolate ascomata have evolved from ostiolate ascomata on several independent occasions. This study agrees with previous studies that show heterothallic Neurospora species to be monophyletic, but that homothallic ones may have a multiple origins. Although Gelasinospora and Neurospora are closely related and not resolved as monophyletic groups, there is insufficient evidence to place currently accepted Gelasinospora and Neurospora species into the same genus.  相似文献   

9.
Osbertia, a stoloniferous group confined to the montane regions of Mexico and adjacent Guatemala, was first proposed as a genus byGreene (1895), but most workers have retained the taxon as part ofHaplopappus. It is clearly closer toNoticastrum, Erigeron orHeterotheca than it is toHaplopappus sensu stricto. The present treatment recognizes two species, a widespread highly variableOsbertia stolonifera and a newly describedO. chihuahuana from northwestern Mexico. Distribution maps, distinguishing features, full synonymy and illustrations are presented.  相似文献   

10.
Comparative floral anatomy and ontogeny in Magnoliaceae   总被引:4,自引:0,他引:4  
Floral anatomy and ontogeny are described in six species of Magnoliaceae, representing the two subfamilies Liriodendroideae (Liriodendron chinese and L. tulipifera) and Magnolioideae, including species with terminal flowers (Magnolia championi, M. delavayi, M. grandiflora, M. paenetalauma) and axillary flowers (Michelia crassipes). The sequence of initiation of floral organs is from proximal to distal. The three distinct outermost organs are initiated in sequence, but ultimately form a single whorl; thus their ontogeny is consistent with a tepal interpretation. Tepals are initiated in whorls, and the stamens and carpels are spirally arranged, though the androecium shows some intermediacy between a spiral and whorled arrangement. Carpels are entirely free from each other both at primordial stages and maturity. Ventral closure of the style ranges from open in Magnolia species examined to partially closed in Michelia crassipes and completely closed in Liriodendron, resulting in a reduced stigma surface. Thick-walled cells and tannins are present in all species except Michelia crassipes. Oil cells are normally present. Floral structure is relatively homogeneous in this family, although Liriodendron differs from other Magnoliaceae in that the carpels are entirely closed at maturity, resulting in a relatively small stigma, in contrast to the elongate stigma of most species of Magnolia. The flower of Magnolia does not terminate in an organ or organ whorl but achieves determinacy by gradual diminution.  相似文献   

11.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae.  相似文献   

12.
Decayed wood from fallen white spruce (Picea glauca) and trembling aspen (Populus tremuloides) collected in northeastern Alberta, Canada, was the source of new isolates of species in the ascomycete generaGymnostellatospora andPseudogymnoascus. In addition to new reports ofG. japonica, G. frigida andP. roseus, two new species are described.Gymnostellatospora canadensis sp. nov. resemblesG. japonica but differs in producing brown ascomata and in the formation of an arthroconidial anamorph.Gymnostellatospora subnuda sp. nov. is distinct in lacking differentiated peridial hyphae.Gymnostellatospora alpina was not found in decayed wood but is reviewed based on extralimital material. A dichtomous key to the five species ofGymnostellatospora is provided.  相似文献   

13.
The tribal name Bocageeae Endlicher is reestablished and the tribe is circumscribed on the basis of solitary internodal ebracteate pedicels that are articulated at the base, and pollen shed in polyads of eight or more grains. Septate anther locules, large pollen size, and seed appendages are prevalent in the tribe. Intectate pollen with free-standing columellae, rare in Annonaceae, occurs not only in the genusTrigynaea but also in some species ofBocagea andHornschuchia. As defined here, the Bocageeae include seven neotropical genera:Cymbopetalum, Porcelia, Bocagea, Cardiopetalum, Froesiodendron, Hornschuchia, andTrigynaea. The latter five genera are revised and the treatments include ten new species:Cardiopetalum plicatum, Froesiodendron urceocalyx, Hornschuchia lianarum, H. santosii, H. leptandra, Trigynaea cinnamomea, T. lanceipetala, T. triplinervis, T. lagaropoda, andT. axilliflora, all from tropical South America. A new combination,Froesiodendron longicuspe, changes the rank of that taxon from subspecies to species.Cardiopetalum surinamense is removed fromFroesiodendron and reassigned toCardiopetalum on the basis of its connate petals, dehiscent monocarps, and seeds with bilobed arils. A cladogram provides an explicit hypothesis of intergeneric relationships in the tribe. The new combinationOnychopetalum periquino, based onTrigynaea periquino, is made.  相似文献   

14.
Laboulbenia stenolophi is reported for the first time from Japan.Stenolophus iridicolor andS. propinquus are added as new hosts. The crowded antheridia and the protruding (bulging) cell IV are characteristic of this fungus, although thalli with an almost normal cell IV sometimes occur.Laboulbenia anoplogenii onAnoplogenius is easily distinguished from what has been calledL. anoplogenii onStenolophus, Astigis, Abacetus andChlaeminus by the following characters: 1) no crowded antheridia can be observed throughout thallus development, but many sterile long branches can be observed instead; 2) cell IV starts to undergo cell division early in thallus development; 3) cell V extends downward to the level of cell VII, rather than extending only as far as the perithecial basal cells; and 4) cell VI is usually longer and extends farther distally than cell III.Anoplogenius is the host genus ofL. anoplogenii and the records from other hosts represent misapplied names.  相似文献   

15.
The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.
  相似文献   

16.
Cynoglossopsis somaliensis H. Riedl, sp. nov., is described as a new species of the hitherto monotypic genusCynoglossopsis Brand which is closest related toCynoglossum L. but has to be included inBoraginoideae-Eritrichieae from the way the nutlets are attached to the gynobasis.
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17.
The leaf blight and mummy fruit disease fungus of Prunus ssiori in northern Japan is newly named M. ssiori, as a fourth member in the M. padi group of section Disjunctoriae of the genus Monilinia (Sclerotiniaceae). It has been misidentified with Monilinia kusanoi, but recent studies show it is different from M. kusanoi as well as other related species on prunaceous hosts in respect to host relation, pathogenicity, morphology, and gene analysis.  相似文献   

18.
The term house-dust mite usually refers to those species of the mite family Pyroglyphidae, that are known to commonly occur, although sometimes regionally, in the dust of human dwellings. These species belong to five genera:Dermatophagoides, Euroglyphus, Hirstia, andMalayoglyphus. Related species ofDermatophagoides have the most world-wide occurrence, the commonest being:D. farinae, D. microceras, andD. pteronyssinus. A correct taxonomic identification of house-dust mites is very important, not only from a biological stand point, but also regarding the consequences of their respective allergenical properties. Several immuno-chemical studies revealed differences between the products of two hard to distinguish sibling species. A preliminary practical taxonomic key for the most common and important house-dust mites is presented.  相似文献   

19.
A ribosomal DNA region, including the entire 5.8S RNA gene and the internal transcribed spacers ITS 1 and ITS 2, was used for studying the phylogeny ofSalicaceae and the relationship betweenSalicaceae andFlacourtiaceae. The length of the ITS regions withinSalicaceae andFlacourtiaceae was similar to that found in other angiosperms. The GC content of both ITS regions was high, varying 62.7-72.2%. The most parsimonious tree clusters the wind-pollinatedChosenia bracteosa among theSalix species, suggesting that it should be included in the genusSalix. The grouping withinSalix leaves subg.Salix as paraphyletic, for which reason the subgeneric division is questionable.Populus was monophyletic and formed a sister group toSalix. The interspecific variation of the ITS sequences was very small inSalicaceae, which is in contradiction to the age of the group according to the evidence from fossil data.Idesia polycarpa fromFlacourtiaceae shows great sequence similarity withSalicaceae, but the analysis of 5.8S rDNA supports monophyly of the four species ofFlacourtiaceae sampled for this study.  相似文献   

20.
The influence of growth rate, the presence of acetate and variation in the dissolved oxygen concentration on the kinetics of nitrite oxidation was studied in suspensions of intact cells of Nitrobacter winogradskyi and Nitrobacter hamburgensis. The cells were grown in nitrite-limited chemostats at different dilution rates under chemolithotrophic and mixotrophic conditions. Growth of N. hamburgensis in continuous culture was dependent on the presence of acetate. Acetate hardly affected the maximal nitrite oxidation rate per cell (V max), but displayed a distinctly negative effect on the saturation constants for nitrite oxidation (K m ) of both Nitrobacter species. This effect was reversible; when acetate was removed from the suspensions the K m -values for nitrite oxidation returned to their original values. A reduction of the dissolved oxygen concentration from 100% to 18% air saturation slightly decreased the V max of chemolithotrophically grown N. winogradskyi cells, whereas a 2.3 fold increase was observed with mixotrophically grown cells of N. hamburgensis. It is suggested that the large variation in K m encountered in field samples could be due to this observed phenotypic variability. The V max per cell is not a constant, but apparently is dependent on growth rate and environmental conditions. This implies that potential nitrite oxidation activity and numbers of cells are not necessarily related. Considering their kinetic characteristics, it is unlikely that N. hamburgensis is able to compete succesfully with N. winogradskyi for limiting amounts of nitrite under mixotrophic conditions. However, at reduced partial oxygen tensions, N. hamburgensis may become the better competitor.  相似文献   

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