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1.
Forty environmental strains and reference cultures of Flavobacterium, Cytophaga and Weeksella spp. were examined by numerical taxonomy. Twenty-seven strains were recovered in four phena. Phena 1A and IB comprised 48% of the strains and were sufficiently similar to the genus Weeksella as to suggest possible inclusion in this genus. They could not be accommodated in the existing species W. virosa and W. zoohelcum. Strains from phenon 2 appear to belong neither in the Flavobacterium or the Weeksella genus. Although no reference strains were included in phena 3 and 4 they appear phenotypically to be most similar to F. breve and F. odoratum respectively.  相似文献   

2.
The genus Ripogonum J. R. et G. Forst. is usually included in either the Smilacaceae or Liliaceae, but it has been accorded family rank. A numerical taxonomic study of the phenetic relationships of Ripogonum and all genera of the Smilacaceae, Dio-Scoreaceae, Petermanniaceae, Philesiaceae and Luzuriagaceae has been undertaken in terms of 56 characters. The results support the view that Ripogonum is only distantly related to either Smilacaceae or Dioscoreaceae and instead has affinities with Luzuriagaceae. None-the-less Ripogonum merits family status and so Ripogona-ceae are formally validated.  相似文献   

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Nogrady  Thomas  Wallace  Robert L. 《Hydrobiologia》1995,313(1):99-104
The genus Notholca has been subjected to taxonomic analysis, using cluster analysis and ordination by principal coordinates analysis, based on 67 phenetic characters. All analyses converge on essentially identical groupings, but fail to inject new hypotheses to remedy the confusing and overlapping taxonomy of the genus. This shortcoming is ascribed to the incompleteness of the character set which currently lacks biochemical and genetic parameters. We suggest to invalidate the subspecies' of N. striata into a single species and consider the pros and cons combining N. haueri and N. latistyla.  相似文献   

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介绍了堇菜属的形态特征与分布并说明其研究历史与现状;以堇菜属为例,对现代植物学分类方法在植物分类研究中的应用进行了论述。  相似文献   

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We have classified 11 species recently recognized as belonging to the genus Elymus into a resurrected and legitimate genus Campeiostachys Drobov according to the International Code of Botanical Nomenclature. Our action is based on the rationale of monophyly, discrimination, and practicality discussed in detail. Currently Elymus contains a vast number of species with different genomes which often, but not always, can be differentiated by cytological and molecular features, but are difficult to separate by tr...  相似文献   

9.
Cultures of Bdellovibrio isolated from different geographic locations have been studied in terms of deoxyribonucleic acid analysis (% G + C, genome size, and DNA hybridization), cytochrome spectrum, and host range. Isolates of the genus exhibit a broad range of % G + C ranging from 37 to 51% and the genome sizes extend from 1300 x 10(6) to 1700 x 10(6) daltons. DNA hybridization continues to reveal a high level of genetic heterogeneity. Bdellovibrio 3294 exhibits 32% relative reassociation to Bdellovibrio W, 37% to Bdellovibrio stolpii Uki2, and an undetectible level to Bdellovibrio starrii A3.12 Bdellovibrio W is 23% related to B. starri A3.12 and 28.5% to B. stolpii Uki2. For the first time differential absorption techniques have revealed peaks of cytochrome b. The analysis of the cytochrome spectrum seems to be limited as a taxonomic tool since most of the recent isolates studied share a common cytochrome spectrum. Host-range studies have been found to be dependent on the experimental conditions, and with the exception of one isolate (B. starrii A3.12) the taxonomic significance of such techniques must be taken with caution.  相似文献   

10.
Echinococcus remains a significant public health problem worldwide and, in several regions, the aetiological agents of cystic hydatid disease/echinococcosis are extending their range. The taxonomy of Echinococcus has been a controversial issue for decades, but the outcome of recent molecular epidemiological studies has served to reinforce proposals made ten years ago to revise the taxonomy of Echinococcus. A formal nomenclature is essential for effective communication, and provides the stability that underpins epidemiological investigations. It will also serve to recognize the contribution of early taxonomists.  相似文献   

11.
A critical review of the sipunculan genus Lithacrosiphon , based on all of the type material and museum specimens with the exception of L. uniscutatus , results in the combining of nine species into three. L. maldivensis with its granular anal shield remains unchanged. L. cristatus with a grooved anal shield and both unidentate and bidentate hooks is redescribed and now includes L. altriconus, L. gurjanovae, L. indicus , and L. odhneri . The L. uniscutatus complex which allegedly has only unidentate hooks is discussed and now includes L. kukenthali and L. poritidis . This is a troublesome species as the pertinent specimens were either unavailable ( L. uniscutatus ) or with missing introverts ( L. kukenthali and L. poritidis ). An identification key is provided and the several morphological characters used for purposes of identification are reviewed and evaluated.  相似文献   

12.
The genus Anisotes Nees is revised. A total of 24 taxa had previously been described. In the present revision 19 species, 3 subspecies and 1 variety are recognized. A new infrageneric classification of Anisotes is proposed.
In the general part the morphology, with special emphasis on pollen morphology, and the diagnostic characters of the genus are outlined. Phytogeographical and ecological aspects are discussed in relation to the phytogeographical division of Africa.  相似文献   

13.
A taxonomic treatment of the genus Ptyssiglottis including Ancylacanthus, Hallieru-cantha, Oreothyrsus , and Polytrema is given. The phylogeny is briefly dealt with. Leaf morphology, inflorescence morphology and pollen morphology yield important characters. The distribution of selected characters is mapped. The distribution of all species is mapped. Eight new species are published viz. P. campanulata, P. decurrens, P. fusca, P. glandulifera, P. longisepala, P mucronata, P. pubescens , and P. staminodifera . Fifteen new combinations are made viz. P. caudata, P. creaghii, P. cuprea, P. cyrtandroides, P. dulcamarioides, P. fastidiosa, P. glabrisepala, P. granulata, P. nigrescens, P. peranthera, P. psychotriifolia, P. pubisepala, P. salicifolia, P. sanguinolenta , and P. undulata .  相似文献   

14.
The genus Cremastra is revised. A total of 8 taxa have earlier been proposed, but in the present revision 2 species are recognized: C. appendiculata and C. unguiculata. Hyacinthorchis variabilis is here considered a variety: C. appendiculata var. variabilis comb. et stat. nov.  相似文献   

15.
The genus Panisea is revised. A total of 13 taxa have previously been described. In the present revision 7 species are recognized: P. albiflora, P. apiculata, P. demissa, P. distelidia sp. nov., P. tricallosa, P. uniflora and P. yunnanensis. A new variety, P. tricallosa var. garrettii is proposed.  相似文献   

16.
A taxonomic treatment of the genus Ptyssiglottis including Ancylacanthus, Hallieracantha, Oreothyrsus , and Polytrema is given. The phylogeny is briefly dealt with. Leaf morphology, inflorescence morphology and pollen morphology yield important characters. The distribution of selected characters is mapped. The distribution of all species is mapped. Eight new species are published viz. P. campanulata, P. decurrens, P. fusca, P. glandulifera, P. longisepala, P. mucronata, P. pubescens , and P. stamino-difera . Fifteen new combinations are made viz. P. caudata, P. creaghii, P. cuprea, P. cyrtandroides, P. dulcamarioides, P. fastidiosa, P. glabrisepala, P. granulata, P. nigrescens, P. peranthera, P. psychotriifolia, P. pubisepala, P. salicifolia, P. sanguinolenta , and P. undulata .  相似文献   

17.
The genus Macrorungia C. B. Clarke is revised. 5 taxa have previously been proposed in the genus; the present revision recognises 3, viz. Macrorungia galpinii C. Baden sp. nov., M. longistrobus C. B. Clarke and M. pubinervia (T. Anders.) C. B. Clarke. The delimitation between Anisotes and Macrorungia is discussed. Phytogeographical and ecological aspects are discussed in relation to the phytogeog–raphical division of Africa.  相似文献   

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Aim Species introductions and extinctions have reorganized the earth's biota, often leaving formerly spatially distinct assemblages more similar in species composition, a process termed biotic homogenization. The study of biotic homogenization has been almost entirely focused on the change in taxonomic similarity between assemblages through time. Here, we provide a trait‐based method for calculating functional similarity through time and compare these trends in functional attributes with those trends generated from a taxonomic perspective. Location Data were produced through computer simulation and gathered from North American Breeding Bird Survey (BBS) data and published accounts of North American birds for 10 locations across the east and west coast of the United States. Methods We simulated change in assemblages with different trait types (binary and continuous), levels of trait overlap, number of traits and species richness to determine the relationship between change in taxonomic similarity (ΔTS) and change in functional similarity (ΔFS). We also assess the relationship between ΔTS and ΔFS for bird assemblages across 10 locales in the USA between 1968 and 2008. We used simple linear regression to determine the slope and correlation between ΔTS and ΔFS and used multiple regression to assess the influence of trait overlap, number of traits, species richness and the ratio of traits to species on the relationship between ΔTS and ΔFS. Results Simulations reveal that trait redundancy governs the relationship between ΔTS and ΔFS. A decrease in trait overlap increases the slope of the regression between ΔTS and ΔFS and an increase in the ratio of traits to species in the regional pool increases the correlation. The relationship between ΔTS and ΔFS for breeding birds is comparable to simulations with low trait redundancy. Main conclusions We show that often losing or gaining species from an assemblage tells us very little about the loss or gain of function, and that this scenario most often occurs when the two assemblages have high trait redundancy. It remains to be seen how prevalent this scenario is within empirical examples; however, the implications for the continued delivery of ecosystem functions in the face of species introductions and extinctions are large.  相似文献   

20.
The present paper is an attempt to propose a preliminary taxomomic treatment of the genus Hippolytia Poljak. and to analyse the geographical distribution of its composite elements. This small genus with 17 species is divided into 2 sections, namely, section Anthodesma Shih and section Hippolytia. Anthodesma is a small section with 3 species and is characterized by fascicled corymbs, campanulate and nitid involucres, rigidly herbaceous phyllaries, and undershrubs, while Hippolytia consisting of 14 species is characterized by corymbose inflorescence or glomerules or compund heads, cuneate and unpolished involucres, herbaceous phyllaries with pitch black margines. There are 12 species of Hippolytia in China, of which 3 are proposed as new in the present paper. Regarding the distribution pattern of Hippolytia, it is noteworthy to note that its range of distribution forms a more or less U-shape as shown in map 2. It may be seen that Hippolytia distributes in Central Asia-Sino-Himalaya-Median Asia. Section Anthodesma Shih occurs in central Asia, while section Hippolytia in the whole Himalayan region and northern Meridional Ranges and Median Asia. There seems to be no center of species concentration within the total range of Hippolytia, whose species are localized in distribution, for example, H. desmantha Shih is known only from Qinghai provence (Yu-Shu-Hsien), H. alashanensis (Ling) Shih is restricted to Ninghsia and central part of Kansu provence. It is interesting to note that H. yunnanensis (J. F. Jeffrey) Shih and H. longifolia (Wall.) Shih are referred to as vicarious species. The localization of the species distribution and the obvious discontinuity of morphological characters between species indicate a remarkable geographical influence on the species formation of Hippolytia. Hippolytia is an alpine genus of temperate zone of Asia, in which 64 per cent of species occurs at high elevations of above 3300m. altitude, 30 per cent of species are distributed in middle elevations of above 2200m. altitude. The life forms are microundershrubs, erect perennial herbs, glomerule stemless herbs or stemless herbs. It is very possible that its geographical origin and development may be linked up with occurance of desert steppe, especially of alpine meadow vegetations in the northern temperate zone of Asia. With regard to the geographical elements to which each species of Hippolytia belongs, it seems to indicate that H. trifida (Turcz.) Poljak., H. alashanensis (Ling) Shih and H. desmantha Shih belong to the geographical elements of central Asia, while H. yunnanensis (J. F. Jeffrey) Shih, H. glomerata Shih, H. tomentosa (DC.) Tzvel., H. senecionis (Bess.) Poljak. H. longifolia (Wall.) Shih, H. kennedayi (Dunn) Ling, H. syncalathiformis Shih, H. gossypina (Hook. f. et Thoms.) Shih and H. nana (C. B. Clarke) Shih to Himalayan elements, and H. darvasica (C. Winkl.) Poljak., H. megacephala (Rupr.) Poljak,, H. herderi (Rgl. et Schmalh.) Poljak. to Median Asia, H. delavayi (W. W. Smith) Shih to North-West-Yunna.  相似文献   

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