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1.
Berlandiera is revised to includeB. subacaulis, B. pumila, B. texana, andB. lyrata with its varietieslyrata andmacrophylla. All species may be induced to interbreed readily, producing F1 progeny which are vigorous but with reduced fertility. Sympatric species produce natural hybrids which are proposed here asB. Xhumilis (=B. pumila XB. subacaulis) andB. Xbetonicifolia (=B. pumila XB. texana). All taxa investigated hadn = 15 chromosomes, including new counts forB. subacaulis and all six F1 hybrids.  相似文献   

2.
Paul A. Fryxell 《Brittonia》1968,20(4):378-386
The five binomials published by Linnaeus inGossypium L. are reviewed, their typification and application dealt with, and some earlier misconceptions concerning them clarified. Holotypes are known forG. herbaceum, G. arboreum, G. hirsutum, andG. religiosum. A lectotype ofG. barbadense is herein designated.G. religiosum is considered synonymous withG. hirsutum. The history of the cultivatedG. hirsutum is discussed in support of the present treatment.  相似文献   

3.
Notes on the taxonomy and distribution of various species of Labiatae of Mexico, and Central and South America, are presented, as part of a continuing series of supplements to the authors’ earlier monographs. Eight new species are described in the generaHyptis, Salvia, Satureja, andScutellaria. Two new combinations are made, one each inHarlanlewisia andSatureja. A key and revision are given for the six species ofLepechinia sect.Parviflorae.  相似文献   

4.
The strains designated in this paper asMicrococcus lysodeikticus, M. sodonensis, M. flavus, Sarcina flava, S. pelagia, S. variabilis, S. marginata, S. subflava, S. citrea, S. lutea andStaphylococcus afermentans have similar DNA base compositions. The mole % GC (guanine plus cytosine) contents in DNA of these strains ranged from 71.8 to 73.3 as calculated from the denaturation temperature (Tm). They may be, therefore, closely related. However, at variance with Kocur and Martinec (1962) they do not seem to be identical withMicrococcus luteus (Schroeter 1872) Cohn 1872, because the neotype culture of the latter species has a different content of guanine and cytosine in its DNA (GC=66.3%). Sarcina aurantiaca, Micrococcus dentrificans andM. luteus have a similar DNA base composition. However, they are not identical as they differ from each other in several physiological characters. In the strains designated asStaphylococcus roseus andSarcina erythromyxa the content of GC varies within the range 72–72.8%. These species do not differ from each other physiologically. They form a pink pigment, reduce nitrates, do not hydrolyze casein and gelatin, and do not produce urease. They seem, therefore, to be identical, which confirms the conclusion of Kocur and Martinec (1962) who designated them asMicrococcus roseus Flügge 1886. Micrococcus conglomeratus differs significantly in DNA base composition from almost all strains of the groupM. lysodeikticus—Staphylococcus afermentans, also fromMicrococcus luteus, M. roseus andM. denitrificans. It differs fromSarcina aurantiaca only physiologically.  相似文献   

5.
Jack Maze 《Brittonia》1968,20(4):321-333
Introgression between two allopatric species,Quercus macrocarpa andQ. gambelii, has been observed in two separate locations: northeastern New Mexico and the Black Hills of western South Dakota and adjacent Wyoming. The probability that this introgression is the result of long-range pollination appears remote. Presumably these two species hybridized during a period of past sympatric association. Further indication of past sympatry in the Black Hills is the presence of a common species of obligate parasite, i.e., wasp(Cynips insulensis) onQ. gambelii in the Rocky Mountains and onQ. macrocarpa of the Black Hills. The hybrid oaks in New Mexico probably reflect a westward migration ofQ. macrocarpa during pluvial periods of the Pleistocene.Quercus gambelii most likely reached the Black Hills during the warmer postglacial hypsithermal era. The hybridization reported here may reflect secondary sympatry, i.e., sympatric occurrence after the species, or their ancestors, became geographically separated.  相似文献   

6.
Seven hitherto unrecognizedSalmonella types are described.S.leiden (13, 22, 36 : z 38),S. enschede (35 : z 10 : l,w) andS. hillegersberg (9, 46 : z 35 : 1,5) were isolated from patients in the Netherlands.S. lawra (44 : k : e,n,z 15) was isolated from a healthy student in Ghana.S. overvecht (30 : a : 1,2),S. woerden (17 : c : z 39) andS. odijk (30 : a : z 39) were isolated from animals kept in zoological gardens in the Netherlands.  相似文献   

7.
David M. Bates 《Brittonia》1967,19(3):227-236
Reevaluation of the generic limits ofMalvastrum A. Gray requires the transfer of several species. Among these,M. lacteum (Ait.) Garcke andM. subtriflorum (Lag.) Hemsley of Central America and Colombia form a natural alliance differing fromMalvastrum in morphological, cytological, and ecological characteristics and are recognized as a new genus,Kearnemalvastrum. The affinities ofKearnemalvastrum within the tribe Malveae are uncertain. Despite the fact thatK. lacteum andK. subtriflorum occupy similar ecological situations, are fully interfertile, and apparently hybridize to some degree in nature, they do maintain their identity and, therefore, are recognized as species.  相似文献   

8.
Eight nonhuman primate species were compared in three experiments utilizing the oddity paradigm. The sample included 4 lemurs (Lemur catta), 26 Old World Monkeys (Macaca mulatta, M. nemestrina, M. speciosa, andCercopithecus nictitans) and 21 New World Monkeys (Cebus apella, Lagothrix humboldti andSaimiri sciurea). EveryS was first trained 60 days on “outside oddity” problems. Next,Ss solved “outside” oddity problems constituted from two short and two tall cylinders, and were tested for their perception of oddity withDavis andMcDonald's (1962) technique of varying the height of the centerplaced but nonreinforced stimulus. In the final experiment,Ss were given ambiguous oddity problems that could be solved either for form or color cues, andEs recorded preference. Cebus and woolly monkeys formed oddity learning sets as well as or better than any of the Macaque monkeys, but relatively poor performances were made by squirrel monkeys, spotnose monkeys, and lemurs. Woolly monkeys were outstandingly accurate in their perception of oddity based on changing stimulus height, no other species approaching them in this skill. Old World Monkeys were much more likely than New World Monkeys to use color as a cue.  相似文献   

9.
Adenine phosphoribosyltransferase (APRT) from a thermophilic bacterial strain Thermus thermophilus НВ27 (TthHB27APRT) belongs to the family of type I phosphoribosyltransferases and catalyzes the magnesium-dependent transfer of 5'-phosphoribosyl group from 5'-phosphoribosylpyrophosphate to N9 adenine nitrogen with formation of adenosine-5'-monophosphate and pyrophosphate. The crystals of the recombinant enzyme suitable for X-ray study were grown in a capillary using the counter-diffusion technique. Crystals with unit-cell parameters α = 69.860 Å, b = 82.160 Å, c = 91.390 Å, α = 90.00°, β = 102.58°, and γ = 90.00° belong to the space group Р21 and contain six enzyme monomers in the asymmetric unit. The set of X-ray data from grown crystals was collected on a Spring-8 synchrotron radiation facility (Japan) and three-dimensional structure of the enzyme was solved at 2.7-Å resolution by molecular replacement method using the BALBES software. The polypeptide fold in the enzyme monomer and the structure of biologically active dimer were described. Based on the comparison with structures of homologous APRTs from a thermophilic strain ThtHB8 and Homo sapiens, positions of active site and a number of functionally important amino acids were located.  相似文献   

10.
11.
Soils high in magnesium derived from ultramafic rocks (serpentine, peridotite, and dunite) in northwestern United States support endemic as well as wide-ranging but edaphically indifferent(bodenvag) species. The latter occur widely on diverse rock formations of the region. Severalbodenvag species are shown to respond ecotypically to ultramafic soils. Of 18 species tested, all but three are differentiated into strains either tolerant or intolerant of ultramafic soils. Tests for edaphic preferences were conducted with seedlings and mature transplants on ultramafic soils. Growth performances were determined in greenhouse pot tests, outdoor soil bins, and by transplants in the wild. Herbaceous perennials (e.g.,Achillea millefolium, Fragaria virginiana, Prunella vulgaris, Rumex acetosella) gave the clearest ecotypic differences. Woody species either showed only slight ecotypic response(Spiraea douglasii var.menziesii andGaultheria shallon) or delayed the expression of their genotypic adaptability(Pinus contorta). Where ultramafic abut non-ultramafic soils, those populations ofbodenvag species that grow in non-ultramafic habitats can have a significant proportion of individuals tolerant to ferromagnesian soils (e.g.,Achillea millefolium). This suggests gene flow between populations of contrasting edaphic sites and possibly preadaptedness for the ultramafic habitat. Strains of two introduced weeds(Prunella vulgaris andRumex acetosella) have become ecotypically tolerant to ultramafic soils, probably within the last 75 years.  相似文献   

12.
The transmission of the carrot mosaic virus (CMV) by the aphidsAcyrtJiosiphon pisum HARRÍS,Cavariela aegopodii SCOP, andMyzus persicae SULZ was proved experimentally. It was observed simultaneously that CMV has a non-persistent character. CMV can be transmitted already 2 min after acquisition feeding by the aphidsMyzus persicae SDLZ andCavariella aego-podii Scop. When the time of acquisition feeding is prolonged to 4 min, CMV is transmitted also by aphidAcyrthosiphon pisum HAREÍs. The host range of the investigated virus wasalso determined and its transmission to 8 plant species, belonging to 4 families, was achieved. On the basis of studies of the vector virus relationship and of the host range, further proof was given for the different character of the Australian Carrot motley dwarf virus, theApivm virus 1 Roland and CMV. The experiments showed that preliminary starving of the aphids for 1 h increases their ability to transmit the virus by 3–3%.  相似文献   

13.
A novel male-sterile maize mutant male sterility 39 (ms39) was obtained from offspring of the commercial hybrid Chuandan No. 9 that had been carried into outer space. A previous study demonstrated that ms39 is controlled by a single recessive nuclear gene, located on the long arm of chromosome 3. Here, we used 1073 mutant individuals derived from the (ms39?×?Mo17) F2 population and sequentially developed new primers to identify markers supporting the fine mapping of ms39. A 365-kb region on chromosome 3 flanked by markers L8 and M30 at a genetic distance of 0.18 and 0.47 cM, respectively, was identified. According to the reference sequence of ZmB73_Ref-Gen_v4, 12 candidate genes were identified within the 365-kb mapping region. Based on cloning and sequence BLAST analysis of the 12 candidate genes, a four-base-pair deletion was found within the exon of Zm00001d043909, which encoded callose synthase12. This four-base-pair deletion resulted in a frameshift mutation in ms39, leading to the earlier termination of the coding protein, and ultimately caused abnormal performance of the callose synthase. Additionally, cytological observation was conducted on a sister cross population (ms39/ms39?×?ms39/Ms39). These observations showed that the tapetum cells of the ms39 mutant appeared abnormal from the dyad stage, and aborted microspores were observed during pollen development. These results lay the foundation for the cloning of ms39 and exploration of the molecular mechanism underlying aborted pollen development in ms39 maize.  相似文献   

14.
Oligaphorurini represent tribe of the subfamily Onychiurinae, which currently comprises 5 genera and 53 species. The present study evaluated the monophyly of Oligaphorurini genera. We investigated phylogenetic relationships among 39 species, representing all extant genera of Oligaphorurini. Both equal- and implied-weighting parsimony analyses were used in phylogenetic reconstruction. The cladistic analyses were based on comprehensive survey of adults’ morphological characters because specimens suitable for molecular studies were not available for the majority taxa. The phylogenetic analysis resulted in the recognition of a monophyletic Chribellphorura, and strongly supported non-monophyly of the previously recognized genera Archaphorura, Dimorphaphorura, Micraphorura, and Oligaphorura. The following new synonymy is recognized: Oligaphorura = Dimorphaphorura syn. nov., = Micraphorura syn. nov., = Archaphorura syn. nov. The general classification of Oligaphorurini is followed by the diagnoses of genera and key to the all known species.  相似文献   

15.

Objectives

We have examined dynamic changes of histone H3 lysine 9 following trimethylation (H3K9me3), the mRNA expression levels of SUV39H1 and SUV39H2 in bovine oocytes and the role in the development of in vitro fertilization (IVF) pre-implantation embryos.

Results

There were strong H3K9me3 signals in germinal vesicle (GV) oocytes but no signals in MII oocytes. H3K9me3 signals were maintained during IVF pre-implantation embryo development. SUV39H1 and SUV39H2 showed significantly higher mRNA expression levels in GV oocytes than MII oocytes (P < 0.01). SUV39H1 showed high mRNA expression level in two-cell embryos, however, SUV39H2 showed high mRNA expression level in four-cell embryos. In other development stage, SUV39H1 and SUV39H2 showed low expression levels.

Conclusion

Bovine IVF pre-implantation embryos maintain strong H3K9me3 signals and SUV39H1 and SUV39H2 are highly expressed at the early development stage of pre-implantation embryos.
  相似文献   

16.
The allele and genotype distribution of two alcohol dehydrogenase genes ADH1B (exon 3 polymorphism A/G (47His)), ADH7 (intron 5 polymorphism G/C) and cytochrome P450 2E1 gene (CYP2E1; 5′-flanking region G/C and intron 6 T/A polymorphisms) were examined in Russian (Tomsk, n = 125) healthy population and in coronary atherosclerosis patients (CA, n = 92). The genotype frequencies followed the Hardy-Weinberg equilibrium and the alleles were in linkage equilibrium or gametic equilibrium in the control sample. Only two CYP2E1 gene polymorphisms were in linkage disequilibrium. The frequencies of the derived alleles at ADH1B * G (+MslI) allele, CYP2E1 * C2 (+PstI) allele and CYP2E1 * C (-DraI) allele were 8.48 ± 1.86, 1.20 ± 0.69, and 10.00 ± 1.90%, respectively. The ADH7 gene polymorphism showed a high level of heterozygosity; the frequency of the ADH7 * C (-StyI) allele was 44.58 ± 3.21%. A significantly higher frequency of CYP2E1 PstI C2 allele has been revealed in the CA group (P = 0.043; OR = 4.23; 95% CI 1.03–20.01). The tendency to significant effect of A1A2 genotype in ADH1B MslI polymorphism was observed for systolic blood pressure in the control group (P = 0.068). The statistically significant two-way interaction effects of ADH7 StyI and CYP2E1 DraI on diastolic blood pressure (P = 0.029) and on the serum high density lipoprotein level (P = 0.042) were also revealed. Association of A1A2 genotype in ADH1B MslI polymorphism with reduced amount in a serum of a very low density lipoprotein level (P = 0.045) have also been shown. This may result from multifunctional activity of alcohol metabolizing enzymes and their involvement in many metabolic and free radical reactions in the body.  相似文献   

17.
Escherichia coli can hardly grow anaerobically on glycerol without exogenous electron acceptor. The formate-consuming methanogen Methanobacterium formicicum plays a role as a living electron acceptor in glycerol fermentation of E. coli. Wild-type and mutant E. coli strains were screened for succinate production using glycerol in a co-culture with M. formicicum. Subsequently, E. coli was adapted to glycerol fermentation over 39 rounds (273 days) by successive co-culture with M. formicicum. The adapted E. coli (19.9 mM) produced twice as much succinate as non-adapted E. coli (9.7 mM) and 62% more methane. This study demonstrated improved succinate production from waste glycerol using an adapted wild-type strain of E. coli with wild-type M. formicicum, which is more useful than genetically modified strains. Crude glycerol, an economical feedstock, was used for the cultivation. Furthermore, the increase in methane production by M. formicicum during co-culture with adapted E. coli illustrated the possibility of energy-saving effects for the fermentation process.  相似文献   

18.
Two new Hyphomycetes collected from Jaipur, Rajasthan, India are described.Panchanania jaipurensis gen. et sp.n., collected on dead and dying twigs ofGrewia salvifolia has characteristic solitary stalked blastospores, each with a dark-coloured head and paler stalk, on sympodulae borne on synnemata.Phragmospathula phoenicis gen. et sp.n., collected on dead leaf rachis ofPhoenix sp. has characteristic solitary spathulate phragmospores (blastospores) which are dark-coloured in the middle and paler at the ends and are produced on short conidiophores capable of proliferation from within. On the basis of the mode of development of the spores, both fungi are placed in the Torulaceae Corda emend. Subram.  相似文献   

19.
Atherosclerosis represents an inflammatory response to the disturbance of the endothelial layer in the arterial bloodstream. In the present study, an analysis of associations of polymorphic markers for the genes controlling synthesis of proteins involved in atherosclerosis pathogenesis in coronary atherosclerosis (CA) patients (217 subjects) and in a control group (250 subjects) was conducted. The following genes were examined: rs991804 (CCL2 gene), rs1126579 (CXCR2 gene), rs4074 (CXCL1 gene), rs4073 (CXCL8 gene), rs333 (CCR5 gene), rs2471859 (CXCR4 gene), rs1801157 (CXCL12 gene), and rs2569190 (CD14 gene). Using the Monte Carlo and Markov chain (APSampler) method, allele/genotype combinations associated with both low and high CA risk were revealed. The most important findings included the following: CXCR4*T/T + CCL2*C + CCR5*I/I (Pperm = 1 × 10–6, OR = 0.44, 95% CI 0.3–0.63), CXCR2*C + CD14*C + CXCL12*G + CCL2*C + CCR5*D (Pperm = 4 × 10–6, OR = 5.78, 95% CI 2.34–14.28), CD14*C + CCL2*C/C + CCR5*D (Pperm = 6.3 × 10–6, OR = 5.81, 95% CI 2.17–15.56), CXCL8*A + CXCR2*C + CD14*T + CXCR4*C (Pperm = 0.01, OR = 3.21, 95% CI 1.63–6.31).  相似文献   

20.
A combined taxonomic revision and wood anatomical study ofDicorynia, a South American genus of legumes that is unusual in both its floral and wood anatomy, is presented. Two possible evolutionary pathways leading to the unique 8-to 10-thecate anthers are discussed, and it is concluded that apical proliferation of the thecal primordia is the more likely. Gross and microscopic features of this silica-accumulating wood are given in detail and contrasted with other legume woods especially those containing silica. Economic uses of the trees, especially the wood ofD. guianensis, are discussed particularly in regard to marine construction. It is suggested that the high resistance of this wood to marine borers lies not so much in its silica content as to the presence of some other chemical. Based on the similarity of floral and fruit structures, the number of species is reduced from 7 to 2:D. guianensis in the Guianas andD. paraensis in the Amazonian region. Vegetative variations in the Amazonian population, previously given species rank, are reduced to 5 new varieties ofD. paraensis.  相似文献   

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