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1.
Taxonomy of the genus Cristulariella is revised, retaining Cristulariella (Crist.) depraedans as the type. Two new species, Crist. cercidiphylli and Crist. corni, are additionally described under the genus. The new anamorphic genus Hinomyces is erected to accommodate Botrytis (Cristulariella) moricola and Cristulariella pruni. A new genus and species, Nervostroma depraedans, is erected in the Sclerotiniaceae to accommodate the teleomorph of Crist. depraedans, with an additional species, Nervostroma cercidiphylli.  相似文献   

2.
Spiny-surfaced species of Prorocentrum form harmful algal blooms, and its taxonomic identity is obscure due to the size and shape variability. Molecular phylogenies reveal two major clades: one for P. cordatum with sequences mainly retrieved as P. minimum, and the other for P. shikokuense with sequences also retrieved as P. dentatum and P. donghaiense. Several closely related clades still need to be characterized. Here, we provide nuclear SSU and LSU rRNA genes, and nuclear ITS region (ITS1-5.8S gene-ITS2) sequences of the strain CCMP3122 isolated from Florida (initially named P. donghaiense) and strains Prorocentrum sp. RCC6871–2 from the Ross Sea, Antarctica. We describe Prorocentrum thermophilum sp. nov. based on the strain CCMP3122, a species also distributed in the open waters of the Gulf of Mexico, New Zealand, and the Arabian Gulf; and Prorocentrum criophilum sp. nov. based on the strain RCC6872, which is distributed in the Antarctic Ocean and Arctic Sea. Prorocentrum thermophilum is roundish (~14 μm long, ~12 μm wide), with an inconspicuous anterior spine-like prolongation under light microscopy, valves with tiny, short knobs (5–7 per μm2), and several (<7) large trichocyst pores (~0.3 μm) in the right valve, as well as smaller pores (~0.15 μm). Prorocentrum criophilum is round in valve view (~11 μm long, 10 μm wide) and asymmetrically roundish in lateral view, the periflagellar area was not discernible under light microscopy, valves with very tiny, short knobs (6–10 per μm2), and at least 12 large pores in the right valve. Other potentially undescribed species of spiny-surfaced Prorocentrum are discussed.  相似文献   

3.
Trichome anatomy was examined by light and scanning electron microscopy in 25 genera of Engler's Saxifragaceae from the southern hemisphere. Four principal categories of trichome were recognized: (1) multiseriate with a glandular head; (2) uniseriate with a glandular head; (3) uniseriate, eglandular; (4) unicellular, eglandular. The shape of eglandular hairs ranges from erect to sickle-shaped to T-shaped. The main taxonomic conclusions are as follows: (a) Vahlia should be excluded from tribe Saxifrageae and a possible relationship with Montinia investigated; (b) Francoa and Tetilta (tribe Francoeae) are closely related, although the relationship of the tribe to its parent subfamily, Saxifragoideae, is unclear; (c) Eremosyne is probably allied to the Escallonioideae; (d) subfamily Brexioideae is heterogeneous in trichome anatomy, but the relationships of its constituent genera remain problematic; (e) subfamily Escallonioideae is heterogeneous in trichome anatomy, although similarities between and within the constituent tribes do exist. Thus Cuttsia and Abrophyllum form a natural group (tribe Cuttsieae), to which Carpodetus (tribe Argophylleae) may also be related; similarity in trichome anatomy between Argophyttum and Corokia (tribe Argophylleae) is substantiated by an extensive survey of all the species, and the data tentatively suggest a possible hydrangeoid affinity for these two genera.Forgesia (tribe Forgesieae) is shown to possess the same kind of hairs in the flowers as Quintinia (tribe Escallonieae), and Choristylis (tribe Forgesieae) is shown to be remarkably similar to Escallonia, prompting a suggestion that the two tribes be merged. Trichome data support the inclusion of Anopterus and Polyosma in their own tribes, although their wider affinities remain unclear. Doubts about the inclusion of the glabrous Tribeles in Escallonioideae are expressed. Our material of the following additional genera Lepuropetalon, Tetracarpaea and Brexia was glabrous and little comment could be made about them.  相似文献   

4.
Phylogenetic relationships of polyploid Aegilops species sharing the U-genome were investigated by analyzing heterochromatin banding patterns of their somatic metaphase chromosomes as revealed by C-banding and fluorescence in situ hybridization (FISH) with the heterochromatin-limited repetitive DNA probes pSc119, pAs1, as well as the distribution of NOR and 5S DNA loci revealed by pTa71 (18S-26S rDNA), and pTa794 (5S rDNA) probes. Seven tetraploid (Ae. triuncialis, Ae. peregrina, Ae. kotschyi, Ae. geniculata, Ae. biuncialis, Ae. columnaris, and 4x Ae. neglecta) and one hexaploid (6x Ae. neglecta) Aegilops species of the U-genome cluster were studied. The Ut and Ct chromosomes of 4x Ae. triuncialis (UtCt) were similar to the diploid donors Ae. umbellulata (U) and Ae. caudata (C). However, the size of the NOR locus on chromosome 5Ut was reduced. Karyotypic analyses confirmed that 4x Ae. peregrina (SpUp) was derived from a hybridization of the diploid species Ae. umbellulata with Ae. longissima, whereas Ae. umbellulata and Ae. sharonensis (or an immediate precursor) were the diploid progenitor species of Ae. kotschyi (SkUk). In both 4x species, the NORs on S-genome chromosomes were inactivated and were accompanied with a decrease or loss of rDNA sequences. Karyotypes of the tetraploid species, Ae. geniculata (UgMg) and Ae. biuncialis (UbMb) differed from each other and from the putative diploid progenitors Ae. umbellulata and Ae. comosa indicating that various types of chromosomal alterations occurred during speciation. Inactivation of major NORs on the M-genome chromosomes, redistribution of 5S rDNA sites, and loss of some minor 18S-26S rDNA loci were observed in Ae. geniculata and Ae. biuncialis. Significant differences in the total amount and distribution of heterochromatin, the number and location of 5S and 18S-26S rDNA loci observed between Ae. columnaris (UcXc)/4x Ae. neglecta (UnXn) and Ae. geniculata/Ae. biuncialis indicate that these species have different origins. Similarities in C-banding and FISH patterns of most Ae. columnaris and 4x Ae. neglecta chromosomes suggest that they were probably derived from a common ancestor, whereas distinct differences of three chromosome pairs may indicate that the divergence of these species was probably associated with chromosomal rearrangements and/or introgressive hybridization. Ae. umbellulata contributed the U genome, however, the source of their second genomes remains unknown. The formation of 6x Ae. neglecta (UnXnNn) was not associated with large modifications of the parental genomes.  相似文献   

5.
6.
Abstract The polymerase chain reaction?restriction fragment length polymorphism technique (PCR?RFLP) was used to compare Rhodnius domesticus (Neiva & Pinto), R. pictipes (Stal), R. prolixus (Stal) and R. stali (Lent, Jurberg & Galvão) (Hemiptera: Reduviidae). The enzyme BstUI differentiated R. domesticus, R. pictipes and R. prolixus, and HhaI differentiated R. domesticus, R. pictipes and R. stali. With the fingerprinting analysis generated by these two enzymes, it was possible to clearly identify all four species in the study.  相似文献   

7.
Summary Four gal negative mutations, which affect the expression of the gal operon severely as described in the preceding paper (Saedler et al.), are characterized as insertions of DNA by CsCl density gradient centrifugation of transducing phages carrying the mutations and by electron microscopy of hybrid DNA molecules in which the insertion forms a singlestranded loop.Mutation galOP in 308 is shown by both procedures to be about twice as large as the three other insertions, which are similar in size. The length of the insertions as determined by electron microscopy corresponds to about 1500 nucleotide pairs galOP in 308 and 800, 700, and 700 nucleotide pairs for galOP in 128, 141, and 306 respectively. Single-stranded regions are seen in hybrid molecules prepared between DNAs from galOP in 306 and 128, 141 or 308 as well as from galOP in 308 and 128. No such single-stranded regions are observed in hybrid molecules between DNAs from galOP in 128 and 141.Thus, at least three of the four insertions are not identical.  相似文献   

8.
Background: Prescribed burning in peatlands is controversial due to concerns over damage to their ecological functioning, particularly regarding their key genus Sphagnum. However, empirical evidence is scarce.

Aims: The aim of the article is to quantify Sphagnum recovery following prescribed burns.

Methods: We completed nine fires at a raised bog in Scotland, achieving a range of fire severities by simulating drought in some plots. We measured Sphagnum cover and chlorophyll fluorescence Fv/Fm ratio (an estimate of photosynthetic capacity) up to 36 months post-fire.

Results: Cover of dominant Sphagnum capillifolium was similar in unburnt and burnt plots, likely due to its high moisture content which prevented combustion. Burning decreased S. capillifolium Fv/Fm 5 months after fire from 0.67 in unburnt plots to 0.44 in low fire severity plots and 0.24 in higher fire severity (drought) plots. After 22 months, Fv/Fm in burnt plots showed a healthy photosynthetic capacity of 0.76 and no differences between severity treatments. Other Sphagnum species showed similar post-fire recovery though their low overall abundance precluded formal statistical analysis.

Conclusions: S. capillifolium is resilient to low–moderate fire severities and the same may be true for a number of other species. This suggests that carefully applied managed burning can be compatible with the conservation of peatland ecosystem function.  相似文献   

9.
K Suto  H Noda 《Biopolymers》1974,13(11):2385-2390
As model peptides of collagen, (Pro-Pro-Gly)n (n = 10, 12, 14, and 15) and (Pro-Pro-Gly)n(Ala-Pro-Gly)m(Pro-Pro-Gly)n (2n + m = 15; m = 1, 3, and 5) were synthesized by the solid-phase method. The final products were pure when checked by high-voltage paper electrophoresis and by amino acid analysis. Elemental composition was also examined.  相似文献   

10.
The Lamm equation has been solved numerically for conditions corresponding to equilibrium runs for a nonlinear concentration dependence of the form s/s0 = (1 + kc)?1. It is shown that the approach to equilibrium is very close to being exponential (in time) as in the case k = 0. We also compare results for the nonlinear case given above with results obtained for linear c-dependence of the form s/s0 = 1 – kc. For relatively high speeds the time required to attain equilibrium may be greatly underestimated by use of the latter approximation. Finally, we present analytic approximations for the concentration distribution at equilibrium and as a function of time.  相似文献   

11.
Three strains TKU9, TKU49 and TKU50T, were isolated from the oral cavities of chimpanzees (Pan troglodytes). The isolates were all gram‐positive, facultative anaerobic cocci that lacked catalase activity. Analysis of partial 16S rRNA gene sequences showed that the most closely related species was Streptococcus infantis (96.7%). The next most closely related species to the isolates were S. rubneri, S. mitis, S. peroris and S. australis (96.6 to 96.4%). Based on the rpoB and gyrB gene sequences, TKU50T was clustered with other member of the mitis group. Enzyme activity and sugar fermentation patterns differentiated this novel bacterium from other members of the mitis group streptococci. The DNA G + C content of strain TKU50T was 46.7 mol%, which is the highest reported value for members of the mitis group (40–46 mol%). On the basis of the phenotypic characterization, partial 16S rRNA gene and sequences data for two housekeeping gene (gyrB and rpoB), we propose a novel taxa, S. panodentis for TKU 50T (type strain = CM 30579T = DSM 29921T), for these newly described isolates.  相似文献   

12.
The occurrence of a kairomonal response of the parasitoid Anagyrus spec. nov. near pseudococci (Hymenoptera: Encyrtidae) to (+)‐(1R,3R)‐cis‐2,2‐dimethyl‐3‐isopropenyl‐cyclobutanemethanol acetate (PcA, namely, planococcyl acetate) and (S)‐(+)‐lavandulyl senecioate (LS), the respective female sex pheromones of its hosts, the citrus mealybug, Planococcus citri (Risso) and the vine mealybug, Planococcus ficus (Signoret) (Homoptera: Pseudococcidae) was investigated. Attraction to the pheromones was tested by employing pheromone traps in field trials and by static air olfactometer bioassays in the laboratory. Female wasps showed a significant response to LS, in both field and olfactometer experiments. No significant response was registered to the sex pheromone of P. citri. Despite the similarity between the structures of LS and its analogue (S)(+)‐lavandulyl isovalerate (LI), no significant response to the latter compound was observed. It seems that differences between the structures of the carboxylate moiety of the respective molecules (LS and LI) markedly affect the kairomonal attractiveness to the parasitoid. The kairomonal response of Anagyrus spec. nov. near pseudococci was neither influenced by the host habitat nor by the host species on which it developed. This suggested innate behaviour of Anagyrus spec. nov. near pseudococci, possibly derived from evolutionary relationships between the parasitoid and P. ficus. The practical implications of the results are discussed.  相似文献   

13.
The Cyanidiophyceae, an extremophilic red algal class, is distributed worldwide in extreme environments. Species grow either in acidic hot environments or in dim light conditions (e.g., “cave Cyanidium”). The taxonomy and classification systems are currently based on morphological, eco-physiological, and molecular phylogenetic characters; however, previous phylogenetic results showed hidden diversity of the Cyanidiophyceae and suggested a revision of the classification system. To clarify phylogenetic relationships within this red algal class, we employ a phylogenomic approach based on 15 plastomes (10 new) and 15 mitogenomes (seven new). Our phylogenies show consistent relationships among four lineages (Galdieria, “cave Cyanidium”, Cyanidium, and Cyanidioschyzon lineages). Each lineage is distinguished by organellar genome characteristics. The “cave Cyanidium” lineage is a distinct clade that diverged after the Galdieria clade but within a larger monophyletic clade that included the Cyanidium and Cyanidioschyzon lineages. Because the “cave Cyanidium” lineage is a mesophilic lineage that differs substantially from the other three thermoacidophilic lineages, we describe it as a new order (Cavernulicolales). Based on this evidence, we reclassified the Cyanidiophyceae into four orders: Cyanidiales, Cyanidioschyzonales, Cavernulicolales ord. nov., and Galdieriales ord. nov. The genetic distance among these four orders is comparable to, or greater than, the distances found between other red algal orders and subclasses. Three new genera (Cavernulicola, Gronococcus, Sciadococcus), five new species (Galdieria javensis, Galdieria phlegrea, Galdieria yellowstonensis, Gronococcus sybilensis, Sciadococcus taiwanensis), and a new nomenclatural combination (Cavernulicola chilensis) are proposed.  相似文献   

14.

A total of 37 actinobacteria were isolated from eighteen lichen samples collected in Thailand. Based on the 16S rRNA gene sequences, they were identified into five genera including Actinoplanes (1 strain), Actinomadura (1 strain), Pseudosporangium (1 strain), Wangella (1 strain) and Streptomyces (33 strains). Among these isolates, strain Ptm05T, Ptm01 and Ptm12 showed low 16S rRNA gene similarity and was selected for the further taxonomic study using the polyphasic approach. These strains showed the highest 16S rRNA gene sequence similarity with Streptomyces sparsogenes ATCC 25498T (97.44–97.72%). Strain Ptm05T was selected for the type strain. The chemical cell composition of the strain was similar to the members of Streptomyces genus. LL-diaminopimelic acids were detected in the peptidoglycan. Menaquinones were MK-9(H8) and MK-9(H6). Phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, one unidentified phospholipid, one unidentified glycolipid and one unidentified lipid were detected as the polar lipids. The predominant cellular fatty acids are anteiso-C15:0, iso-C15:0, iso-C16:0, iso-C17:0 and C16:0. The dDNA-DNA hybridization values among strain Ptm05T and its closely related Streptomyces type strains were 17.2–18.0%. In addition, the ANIb and ANIm between strain Ptm05T and related Streptomyces type strains were ranged from 75.69 to 76.13% and 85.21 to 85.35%, respectively. Based on phenotypic and genomic evidence, strain Ptm05T (=?TBRC 14546T?=?NBRC 115203T) represents the novel species of the genus Streptomyces for which the name Streptomyces parmotrematis sp. nov. is proposed. This study showed that the lichens are the promising source of the novel actinobacterial taxa.

  相似文献   

15.
 Six polyploid Aegilops species containing the D genome were studied by C-banding and fluorescence in situ hybridization (FISH) using clones pTa71 (18S-5.8S-26S rDNA), pTa794 (5S rDNA), and pAs1 (non-coding repetitive DNA sequence) as probes. The C-banding and pAs1-FISH patterns of Ae. cylindrica chromosomes were identical to those of the parental species. However, inactivation of the NOR on chromosome 5D with a simultaneous decrease in the size of the pTa71-FISH site was observed. The Nv and Dv genomes of Ae. ventricosa were somewhat modified as compared with the N genome of Ae. uniaristata and the D genome of Ae. tauschii. Modifications included minor changes in the C-banding and pAs1-FISH patterns, complete deletion of the NOR on chromosome 5Dv, and the loss of several minor 18S-5.8S-26S rDNA loci on Nv genome chromosomes. According to C-banding and FISH analyses, the Dcr1 genome of Ae. crassa is more similar to the Dv genome of Ae. ventricosa than to the D genome of Ae. tauschii. Mapping of the 18S-5.8S-26S rDNA and 5S rDNA loci by multicolor FISH suggests that the second (Xcr) genome of tetraploid Ae. crassa is a derivative of the S genome (section Emarginata of the Sitopsis group). Both genomes of Ae. crassa were significantly modified as the result of chromosomal rearrangements and redistribution of highly repetitive DNA sequences. Hexaploid Ae. crassa and Ae. vavilovii arose from the hybridization of chromosomal type N of tetraploid Ae. crassa with Ae. tauschii and Ae. searsii, respectively. Chromosomal type T1 of tetraploid Ae. crassa and Ae. umbellulata were the ancestral forms of Ae. juvenalis. The high level of genome modification in Ae. juvenalis indicates that it is the oldest hexaploid species in this group. The occurrence of hexaploid Ae. crassa was accompanied by a species-specific translocation between chromosomes 4Dcr1 and 7Xcr. No chromosome changes relative to the parental species were detected in Ae. vavilovii, however, its intraspecific diversity was accompanied by a translocation between chromosomes 3Xcr and 3Dcr1. Received July 24, 2001 Accepted October 1, 2001  相似文献   

16.
SUMMARY 1. Growth, reproduction and life‐history parameters were measured for three cladoceran species from a small south‐eastern wetland, U.S.A. Simocephalus serrulatus, Diaphanosoma brachyurum and Scapholeberis mucronata juveniles were reared at temperatures between 10 and 25 °C on natural food resources. 2. Growth rate increased with temperature and decreased with individual size for all three species. Maximum somatic growth rate was higher for Simocephalus (49–72% day?1) and Diaphanosoma (21–91% day?1) than for Scapholeberis (11–45% day?1). Multiple regression equations were developed which predict temperature‐ and mass‐specific growth rates for each species. 3. Scapholeberis egg production was positively related to temperature; however, maximum egg production occurred at intermediate temperatures for Simocephalus and Diaphanosoma. Mean cumulative egg production was higher for Scapholeberis (28–92 eggs per female) than for Simocephalus (18–25 eggs per female) and Diaphanosoma (1–41 eggs per female), and was related to differences in reproductive strategy and survival. 4. Survival was inversely related to temperature in most cases. For all three cladocerans, the intrinsic rate of increase (r) and net reproductive rate (R0) increased with temperature, whereas generation time (G) decreased. Greater egg production by Scapholeberis compared with the other two cladocerans was consistent with higher R0 values for Scapholeberis at any given temperature. Although r was very similar among species, G was typically longer for Scapholeberis than for Simocephalus and Diaphanosoma. 5. This analysis provides basic information about the population parameters of these coexisting wetland species, and the growth rate models can be applied to field data to determine production dynamics.  相似文献   

17.
A new basal land plant, Teruelia diezii gen. et sp. nov., is described from the shallow‐water marine deposits of the Lower Devonian (Lochkovian–Pragian) Nogueras Formation of the Iberian Peninsula (north Gondwana palaeocontinent). Teruelia is preserved as a compression fossil and consists of isotomously branched, robust stems terminated in large, fusiform, twisted sporangia. This morphology suggests that Teruelia is very probably equivalent to Aglaophyton, a permineralized early polysporangiophyte known up to now only from the Lower Devonian (early Pragian to ?earliest Emsian) Rhynie Chert in Scotland (Laurussia palaeocontinent), which represents an early terrestrial hot‐spring ecosystem. Accepted phylogenies identify Aglaophyton as sister to vascular plants. Our phylogeny‐based results identify the Aglaophyton/Teruelia biological entity (i.e. Aglaophyton anatomical characters plus Teruelia external morphology) as the most direct vascular plant precursor. It shows that at least one Rhynie Chert type plant had a much wider distribution than previously known and suggests that Aglaophyton was not restricted to hydrothermal environments, unlike other Rhynie Chert plants.  相似文献   

18.
We have generated solutions to the Lamm equation to examine the effects of concentration dependence on velocity experiments. Two forms of c dependence are considered: s/s0 = 1 – kc and s/s0 = (1 + kc)?1. Features of these solutions are discussed. The magnitude of the errors resulting from the usual procedure of measuring the rate of movement of schlieren maxima or of the position at which the concentration is one half the plateau value have been examined. These errors are usually negligible after sufficient centrifugation time. The errors in using the half-plateau concentration are less than those using the movement of the peak. We have also examined a technique due to Fujita for determining D from boundary spreading when s/s0 = (1+kc)?1. This method is satisfactory when s/s0 is actually of this form, or under certain limitations when s/s0 = (1 + kc)?1. Creeth has shown that under certain conditions the concentration gradient, curve remains virtually unchanged in shape after separating from the meniscus. When this occurs it is possible to estimate s/D from the data. The condition for such a steady state is that kc0 be sufficiently large. Numerical confirmation of this method is presented in the final section.  相似文献   

19.
The systematic position of the Malagasy Phlebotomus (Diptera: Psychodidae) species was assessed in molecular phylogenetic studies. Three molecular markers were sequenced: cytochrome b of the mitochondrial DNA; ITS2, and the D8 domain of the ribosomal DNA. The following species were studied: Phlebotomus (Anaphlebotomus) berentiensis, Phlebotomus (Anaphlebotomus) fertei, Phlebotomus (Anaphlebotomus) fontenillei, Phlebotomus (Anaphlebotomus) vaomalalae and Phlebotomus (Anaphlebotomus) vincenti from Madagascar; Phlebotomus (Anaphlebotomus) stantoni from Asia, and Phlebotomus (Anaphlebotomus) rodhaini from Africa. The following outgroups were selected: Phlebotomus (Euphlebotomus) argentipes, Phlebotomus (Euphlebotomus) barguesae, Phlebotomus (Larroussius) perfiliewi s.l. and Phlebotomus (Adlerius) simici. Each marker analysed by maximum parsimony and maximum likelihood supports the monophyly of the Malagasy Phlebotomus spp. Consequently, we create a new subgenus for these species: Madaphlebotomus subg. nov. This molecular individualization is reinforced by the originality of their spermathecae and by the fact that their geographical distribution is limited to Madagascar, and considers the high level of endemism on this island.  相似文献   

20.
The O-specific polysaccharide chains (O-antigens) of the lipopolysaccharides of five Proteus strains, P. vulgaris O17, P. mirabilis O16 and O33, and P. penneri 31 and 103, were found to contain phosphate groups that link the non sugar components, e.g., ethanolamine and ribitol. The polysaccharides of P. mirabilis O16 and P. penneri 103 include ribitol phosphate in the main chain and thus resemble ribitol teichoic acids of Gram-positive bacteria. The structures of the polysaccharides were elucidated using NMR spectroscopy, including two-dimensional 1H, 1H correlation spectroscopy (COSY and TOCSY), nuclear Overhauser effect spectroscopy (NOESY or ROESY), and H-detected 1H, 13C and 1H, 31P heteronuclear multiple-quantum coherence spectroscopy (HMQC), along with chemical methods. The structures determined are unique among the bacterial polysaccharides and, together with the data obtained earlier, represent the chemical basic for classification of Proteus strains. Based on structural similarities of the O-specific polysaccharides and serological relationships between the O-antigens, we propose to extend Proteus serogroups O17 and O19 by including P. penneri strains 16 and 31, respectively.  相似文献   

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