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1.
European representatives of Apium sensu lato (Apiaceae), and Apium prostratum and Naufraga balearica, were studied with morphological, fruit anatomical, and palynological methods. Morphometric data were compared with phylogenetic results from previous molecular studies. This confirms that most of the European Apium species belong to a separate group corresponding to the previously named genus Helosciadium. All these species had previously been formally named as Helosciadium species, except for the new combination Helosciadium bermejoi, which is formally described here. Molecular studies place Apium prostratum and Naufraga balearica close to Apium graveolens, the type species of Apium. Our morphometric results show similarities of Naufraga with H. bermejoi, but fruit anatomy distinguishes it both from Helosciadium and from A. graveolens/prostratum. The placement of Cyclospermum leptophyllum in a separate genus is confirmed. Diagnostic keys to the genera and Helosciadium species, and an annotated checklist are given.  相似文献   

2.
《Carbohydrate research》1986,149(2):263-277
Partially methylated and acetylated 3-deoxyoctitols were prepared from derivatives of 3-deoxy-d-manno-2-octulosonic acid (KDO), and identified as the d-glycero-d-talo and d-glycero-d-galacto isomers by g.l.c.-m.s. Mono- and oligosaccharide derivatives of KDO were subjected in sequence to methylation, carboxyl-reduction, hydrolysis, carbonyl-reduction, and acetylation to yield 1,2,6-tri-O-acetyl-3-deoxyoctitol derivatives. Carboxyl-reduction and then methylation gave the series of 2,6-di-O-acetyl derivatives. Oligosaccharides with KDO at the reducing end, e.g., β-d-ribofuranosyl-(1→7)-KDO, α-l-glycero-d-manno-heptopyranosyl-(1→5)-KDO, and α-KDOp-(2→4)-KDO, yielded, after carbonyl-reduction, methylation, carboxyl-reduction, hydrolysis, and acetylation, the 1,7-, 1,5-, and 1,4-di-O-acetyl derivatives, whereas remethylation after carboxyl-reduction gave the 7-, 5-, and 4-O-acetyl derivatives of 3-deoxyoctitol. General rules for the fragmentation of 3-deoxyoctitols during e.i.-m.s. were established.  相似文献   

3.
Precursors of the tail of bacteriophage λ have been detected by measurements of in vitro complementation activities and serum blocking activity in sucrose gradients of lysates defective in tail genes.On the basis of these measurements, a pathway for the assembly of the λ tail is proposed:The morphogenesis of the λ tail starts from the tail fiber (product of gene J) located at the distal end of the tail, and proceeds to the proximal end. Gene J by itself produces a 15 S structure with serum blocking activity but without any detectable in vitro complementation activity, which may be the least advanced precursor of the λ tail or an abortive product. Functions of genes J, I, K, L are required for the formation of a 15 S precursor that has in vitro complementation activities with J, I, K and L lysates and serum blocking activity. If the products of genes G and H act on the latter 15 S precursor, a 25 S precursor is made, but this precursor seems either to be in equilibrium with the 15 S precursor or to degrade easily into the 15 S precursor. Gene M has a function of stabilizing the 25 S precursor. After the action of gene M product, the 25 S precursor is ready to serve as a nucleus on which the product of gene V (the major tail protein) assembles. However, gene U product is also necessary at this step for the correct assembly of the major tail protein on the 25 S precursor. Without gene U product the assembly of the major tail protein does not stop at the correct length and a polytail is formed instead of a morphologically normal tail. Finally, gene Z product acts on the morphologically normal tail and makes it a biologically active tail. Without the action of gene Z product, the defective tail binds to a head and forms a phage-like particle which is only very weakly infectious. (The position of gene T in the pathway is not determined, because no sus mutant is available in gene T.)Two abnormal, less efficient pathways are also present in vitro. (1) If gene U product acts on a polytail in an U lysate, the polytail finally binds to a head and forms a phage particle with an extra long tail which is infectious to a small extent. (2) The function of gene K seems to be bypassed to some extent: K lysates accumulate particles which sediment as fast as normal phage and which are complemented by other tail lysates.  相似文献   

4.
In a field survey in the Taiwan Strait during April 2016, the species composition and the domoic acid production of the diatom genus Pseudo-nitzschia were investigated. A total of 80 strains of Pseudo-nitzschia were established, and species identification was determined based on a combination of morphological and molecular data. Fourteen taxa were recognized, i.e., P. americana, P. brasiliana, P. calliantha, P. cuspidata, P. galaxiae, P. lundholmiae, P. multiseries, P. multistriata, P. pseudodelicatissima, P. pungens var. aveirensis, P. pungenus var. pungens and P. sabit, as well as two novel species P. chiniana C.X. Huang & Yang Li and P. qiana C.X. Huang & Yang Li. Morphologically, P. chiniana is characterized by striae comprising one or two rows of poroids, and valve ends that are normally dominated by two rows of poroids within each stria. Whereas P. qiana is unique by having a narrow valve width (1.3–1.5 μm) and sharply pointed valve ends. Both taxa constitute their own monophyletic lineage in the phylogenetic analyses inferred from LSU and ITS2 rDNA, and are well differentiated from other Pseudo-nitzschia species. Pseudo-nitzschia chiniana forms a group with P. abrensis and P. batesiana in LSU and ITS trees, whereas P. qiana is sister to P. lineola. When comparing ITS2 secondary structure, five CBCs and seven HCBCs are recognized between P. chiniana and P. abrensis, and four CBCs and ten HCBCs between P. chiniana and P. batesiana. Two CBCs and eight HCBCs are found between P. qiana with P. lineola. The ability of the strains to produce domoic acid was assessed, including a potential toxin induction by the presence of brine shrimps. Results revealed production of domoic acid in six strains belonging to three species. Without presence of brine shrimps, cellular DA (pDA) was detected in four P. multiseries strains (1.6 ± 0.3, 26.6 ± 2.7, 68.3 ± 4.2 and 56.9 ± 4.7 fg cell−1, separately), one strain of P. pseudodelicatissima (0.8 ± 0.2 fg cell−1) and one strain of P. lundholmiae (2.5 ± 0.4 fg cell−1). In the presence of brine shrimps, pDA contents increased significantly (p < 0.05) in P. lundholmiae (strain MC4218) and P. multiseries (strain MC4177), from 2.5 ± 0.4 to 8.9 ± 0.7 and 1.6 ± 0.3 to 37.2 ± 2.5 fg cell−1 respectively.  相似文献   

5.
Tylenchulus graminis n. sp. and T. palustris n. sp. are described and illustrated from broomsedge (Andropogon virginicus L.) and pop ash (Fraxinus caroliniana Mill.), respectively. T. graminis resembles T. furcus in having a distinct anus, but T. graminis second-stage juveniles (J2) do not have a bifid tail. T. semipenetrans does not have a perceptible anus. The mature female of T. graminis has a mucronate pointed terminus while T. semipenetrans has a smooth and round terminus. T. graminis males have wider stylet knobs and basal bulb and a longer tail than T. semipenetrans males. T. graminis J2 have a longer posterior body portion (without large fat globules) than T. semipenetrans J2. T. palustris resembles T. semipenetrans in having an undetectable anus but differs by the short and conoid mature female postvulval section. The male of T. palustris has larger stylet knobs and basal bulb than those of T. semipenetrans and a bluntly rounded tail terminus, which is tapered in T. semipenetrans. T. palustris differs from T. furcus and T. graminis in having an undetectable anus, by the conoid postvulval section of mature females, by the shorter and rounded tail of males, and the shorter J2 posterior body section without large fat globules. T. graminis and T. palustris are parasites of indigenous flora of Florida.  相似文献   

6.
Taxaceae s. l. is a wider concept of classification treating five genera of Taxaceae s. str. and Cephalotaxus together. Cephalotaxus is morphologically very similar to the five genera of Taxaceae s. str. Various models of classification for six genera have already been published. However, the phylogenetic position and genuine relationships of these genera and species are still confusing. A cladistic analysis of Taxaceae s. l. has been carried out to resolve the problem existing in their phylogeny and to provide a new approach regarding the relationships of these six genera. Parsimony analyses were based on 28 characters and eight genera including two outgroups Agathis and Sciadopitys. The most parsimonious tree retained with branch length 38 and 194 rearrangement trials. Consistency index was 0.68 and retention index was 0.66. Principally, two main clades were found: one represented by Austrotaxus forming the base of the tree and another by the remaining five genera. Taxus + Pseudotaxus clade split after Austrotaxus, and Cephalotaxus was sister to Torreya + Amentotaxus clade. Taxus + Pseudotaxus clade was supported by the highest bootstrap value. Finally, cladistic analysis does not support existence of Cephalotaxaceae. Therefore, it would be better to classify Cephalotaxus within Taxaceae s. l. with the other five genera.  相似文献   

7.
A significant heterogeneity of the species Zygowilliopsis californica was revealed using RFLP-analysis of the PCR-amplified rDNA fragment spanning the 5.8S rRNA gene and the internal transcribed spacers ITS1 and ITS2. Phylogenetic analysis of the nucleotide sequences of ITS1 and ITS2 rDNA differentiated three varieties: Z. californica var. californica, Z. californica var. dimennae, and Z. californica var. fukushimae. The most variable was the ITS2 region, where 7–26 nucleotide substitutions were revealed. The varieties formed semisterile hybrids with meiotic segregation of control markers. The limits of the phylogenetic species concept are discussed.  相似文献   

8.
Chromosome numbers are reported for 20 collections of Mongolian plants representing 19 taxa. The first chromosome records are reported forArabidopsis mongolica (2n=16),Caragana pygmaea (2n=16),Isatis costata var.leiocarpa (2n=28),Lophanthus chinensis (2n=18) andStevenia cheiranthoides (2n=32). Counts partly differing from those previously recorded are given forBatrachium trichophyllum subsp.trichophyllum (2n=32+0-2B, 36+6B),Cuscuta chinensis (2n=60),Dracocephalum fragile (2n=72) andErysimum flavum (2n=14). Chromosome numbers of the following taxa were confirmed:Astragalus monophyllus (2n=16),Erodium stephanianum (2n=16),Gastrolychnis apetala (2n=24),Geum aleppicum (2n=42),Linum baicalense (2n=18),Rorippa palustris (2n=32),Rubia cordifolia subsp.pratensis (2n=22),Schizonepeta multifida (2n=12),Tribulus terrestris (2n=36) andVicia cracca (2n=14). Taxonomic remarks onArabidopsis mongolia, Erysimum flavum, Stevenia cheiranthoides andVicia cracca are added. A new combinationArabidopsis mongolica (Botsch.)Měsí?ek & Soják is proposed.  相似文献   

9.
Immunological studies of Fe-containing superoxide dismutase (FeSOD) and glutamine synthetase (GS) have established a close relationship betweenOceanospirillum linum (the type species of the genus),O. beijerinckii, Alteromonas communis, A. vaga, and two unnamed species of marine bacteria (groups H-1 and I-1). The four latter species have, consequently, been assigned to the genusOceanospirillum asO. commune comb. nov.,O. vagum comb. nov.,O. kriegii sp. nov. (group H-1; type strain 197, ATCC 27133), andO. jannaschii sp. nov. (group I-1; type strain 207, ATCC 27135). The phenotypic properties of these species are presented together with their distinguishing traits.  相似文献   

10.
11.
We describe and illustrate two new species of Boletellus section Boletellus, B. aurocontextus sp. nov. and B. areolatus sp. nov., which are generally assumed to be B. emodensis. In this study, we reconstructed separate molecular phylogenetic trees of section Boletellus using the nucleotide sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA, the largest subunit (RPB1) and the second-largest subunit (RPB2) of nuclear RNA polymerase II gene and mitochondrial cytochrome oxidase subunit 3 (cox3) gene. We also examined the morphologies of B. emodensis sensu lato (s.l.) and other related species for comparison. The molecular phylogenetic tree inferred from the sequences of nuclear DNA (ITS, and combined dataset of RPB1 and RPB2) indicated that three genetically and phylogenetically well-separated lineages were present within B. emodensis s.l. These three lineages were also distinguished on the basis of the molecular phylogenetic tree constructed using the sequences of mitochondrial DNA (cox3), suggesting distinct cytonuclear disequilibria (i.e., evidence of reproductive isolation) among these lineages. Therefore, these three lineages can be treated as independent species: B. aurocontextus, B. areolatus, and B. emodensis. Boletellus aurocontextus and B. areolatus are also distinct from B. emodensis by the macro- and microscopic morphologies. Boletellus aurocontextus is characterized by a pileus with bright yellow to lemon yellow context, which can be observed through a gap in the scales, and basidiospores with relatively large length (mean spore length, 21.4 μm; quotient of spore length and width, 2.51). In contrast, B. areolatus is characterized by a pileus with floccose to appressed thin scaly patches, a stipe with pallid or pale cream color at the upper half, and basidiospores with relatively small length (mean spore length, 16.5 μm; quotient of spore length and width, 1.80).  相似文献   

12.
13.
《Carbohydrate research》1986,154(1):103-113
A direct synthetic route from methyl α-d-glucopyranoside to 3,6-dideoxy-3-(methylamino)hexoses having the d-gluco, d-galacto, and d-manno configurations has been developed. Methyl α-d-glucoside was converted into the 4,6- <O-benzylidene-2,3,-di-O-tosyl derivative, which has then transformed into the 4-O-benzyl-6-deoxy 2,3-ditosylate (5) by successive reductive cleavage of the acetal ring, iodination, and reduction. The intermediate 5 was readily converted into the allo 2,3-epoxide, which yielded the pivotal intermediate methyl 4-O-benzyl-3,6-dideoxy-3-(methylamino)-α-d-glucopyranoside (7) by cleavage of the oxirane ring with methylamine. The amino compound 7 can be directly converted into the derivatized galacto and manno derivatives for mass-spectrometric identification by selective inversion at C-4 and C-2, respectively, followed by hydrolysis, reduction, and acetylation.  相似文献   

14.
Streptomyces thermoautotrophicus UBT1T has been suggested to merit generic status due to its phylogenetic placement and distinctive phenotypes among Actinomycetia. To evaluate whether ‘S. thermoautotrophicus’ represents a higher taxonomic rank, ‘S. thermoautotrophicus’ strains UBT1T and H1 were compared to Actinomycetia using 16S rRNA gene sequences and comparative genome analyses. The UBT1T and H1 genomes each contain at least two different 16S rRNA sequences, which are closely related to those of Acidothermus cellulolyticus (order Acidothermales). In multigene-based phylogenomic trees, UBT1T and H1 typically formed a sister group to the Streptosporangiales-Acidothermales clade. The Average Amino Acid Identity, Percentage of Conserved Proteins, and whole-genome Average Nucleotide Identity (Alignment Fraction) values were ≤58.5%, ≤48%, ≤75.5% (0.3) between ‘S. thermoautotrophicus’ and Streptosporangiales members, all below the respective thresholds for delineating genera. The values for genomics comparisons between strains UBT1T and H1 with Acidothermales, as well as members of the genus Streptomyces, were even lower. A review of the ‘S. thermoautotrophicus’ proteomic profiles and KEGG orthology demonstrated that UBT1T and H1 present pronounced differences, both tested and predicted, in phenotypic and chemotaxonomic characteristics compared to its sister clades and Streptomyces. The distinct phylogenetic position and the combination of genotypic and phenotypic characteristics justify the proposal of Carbonactinospora gen. nov., with the type species Carbonactinospora thermoautotrophica comb. nov. (type strain UBT1T, = DSM 100163T = KCTC 49540T) belonging to Carbonactinosporaceae fam. nov. within Actinomycetia.  相似文献   

15.
The reaction of 1,4-anhydro-2-deoxy-5,6-O-isopropylidene-d-arabino-hex-1-enitol (1) with m-chloroperbenzoic acid in ethanol gives 2,3-unsaturated ethyl glycosides together with saturated ethyl glycosides formed by trans-ring opening of 1,2-epoxide intermediates. Similar results are obtained on peroxidation of 1,4-anhydro-2-deoxy-3-O-(2,3:5,6-di-O-isopropylidene-α-d-mannofuranosyl)-5,6-O-isopropylidene-d-arabino-hex-1-enitol (2). Products resulting from osmylation of 1 and 2 and cleavage of the osmate esters are also described. 2-Deoxy derivatives are prepared from 1 and 2 by methoxymercuration-demercuration and also by reduction of 2-bromo-2-deoxy derivatives obtained by ethoxybromination.  相似文献   

16.
A comparative chemical analysis of Agastache mexicana subsp. mexicana and A. mexicana subsp. xolocotziana reveals that their methanol extracts constituents were very similar, with acacetin and (2-acetyl)-7-O-glucosyl acacetin being the most abundant compounds obtained. These results are consistent with the information reported for other species of Agastache. However, GS-MS analyses showed that methyl chavicol, limonene and linalool were the main constituents of the essential oils of A. mexicana subsp. mexicana, while pulegone, menthone and isopulegone were the major constituents found in A. mexicana subsp. xolocotziana. Furthermore, a different composition was found in their respective hexane extracts. These chemical composition dissimilarities between the two taxa support their recognition as distinct subspecies.  相似文献   

17.
The Kungurian and Upper Permian beds of western Angaraland yield a number of alleged predecessors of Mesozoic flora including Rhaphidopteris praecursoria sp. nov., the oldest representative of the genus hitherto known from the Jurassic only. R. praecursoria shows remarkably variable frond structures. Possible phyletic links between the Permian Rhaphidopteris, Triassic Corystospermaceae, and Jurassic Pachypteris and Rhaphidopteris are suggested.  相似文献   

18.
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20.
Results of the present study indicate that male cones of Pseudotaxus chienii are representing inflorescences with strongly reduced flowers. The results fit quite well with investigations showing that sporangiophores of Taxus and also of Pseudotaxus comply with reduced flowers. The only difference between male cones in Taxus and Pseudotaxus is the absence of pherophylls in Taxus. Furthermore our results complete a transition series beginning with Cephalotaxus going on to Pseudotaxus and ending with Taxus and Torreya. In this progression Pseudotaxus can be regarded as an intermediate link between the inflorescences of Cephalotaxus and the simple, unbranched cones of Taxus. The entire transition series shows that sporophyll-like sporangiophores can be derived by reduction of lateral cones. There is however no sign that a similar process has occurred in other conifer groups.  相似文献   

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