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11.
Stimulation of in vitro shoot proliferation from nodal explants of cassava by thidiazuron, benzyladenine and gibberellic acid 总被引:2,自引:0,他引:2
Basdeo Bhagwat Luiz G. F. Vieiral Larry R. Erickson 《Plant Cell, Tissue and Organ Culture》1996,46(1):1-7
Multiple shoots were produced from nodal explants of cassava (Manihot esculenta Crantz) by a two-step procedure: a 6- to 8-day exposure to 0.11–0.22 µM thidiazuron (TDZ) in liquid Murashige and Skoog (MS) medium followed by culture on agar-solidified MS medium supplemented with 2.2 µM 6-benzyladenine (BA) and 1.6 M gibberellic acid (GA3). TDZ caused the nodal explants to expand and this expansion (growth) continued during culture with BA and GA3. From this expanded explant, clusters of buds and fasciated stems developed continuously and these gave rise to shoots. The shoot proliferation process was open-ended, yielding an average of 31.5 shoots per nodal explant after 10 weeks of culture with genotype CG 1–56. A positive response was also obtained from seven other genotypes evaluated with this protocol.Abbreviations BA
6-benzyladenine
- BM
basal medium
- DPU
1,3-diphenylurea
- GA3
gibberellie acid
- 2iP
isopentenyladenine
- MSM
multiple shoot medium
- NAA
1-naphthaleneacetic acid
- PGR
plant growth regulator
- TDZ
thidiazuron
- Z
zeatin 相似文献
12.
Marcello Franco Eduardo Bagagli Marino Cunha Luiz Gastão Chamma Denise Fecchio 《Mycopathologia》1996,135(1):13-19
We investigated the occurrence of antigenic and biochemical variability among Paracoccidioides brasiliensis antigen batches prepared according to the same protocol. Initially (experiment #1), we analyzed two antigen lots of two human isolates (Bt1 & Bt2), cultured in two media (PYG: bactopeptone, yeast extract, glucose; MMM: McVeigh & Morton medium) in SDS-PAGE and in two immunological tests (imunodiffusion-ID and footpad swelling test-FPT). Afterwards (experiment #2), we compared the antigenic profile of three antigen batches from three human isolates (Bt1, Bt2 & Bt3) by two-dimensional immunoelectrophoresis (2 D-IEP) against a reference system for P. brasiliensis antigens. In experiment #1, there were important intra- and inter-strain antigenic differences between batches of the fungal isolates cultured on both media. The block titration of the antigen batches for the immunological tests revealed correlation between protein concentration and biological activity in ID and no correlation in FPT. In experiment #2, the reference system for P. brasiliensis showed 26 antigen peaks. There were important differences between batches prepared from the same isolate and between batches from different isolates. Our data suggested the occurrence of instability in the synthesis of antigenic components by a same P. brasiliensis isolate, under controlled incubation conditions. 相似文献
13.
European Atlantic salmon (Salmo salar) populations inhabit rivers from northern Portugal to northern Norway across a wide spectrum of environmental variability. To address whether single physical factors might lead to genetic divergence of isolated populations, we compared the digestive performances total digestibility, relative nitrogen digestibility, passage time, and digestion rate (g dry matter · h–1) — of northern (Scotland) and southern (Asturias, northern Spain) populations at three temperature regimes (5, 12, and 20° C). Total dry matter digestibilities increased directly with temperature but were similar for both populations at each of the three trials. Relative nitrogen digestibility did not differ between populations nor among temperature regimes. In contrast, passage time was significantly longer for low-than for high-latitude fish at both 5 and 20° C. When the percentage of food digested and the passage time were integrated as digestion rates (food digested per unit time), a significant population × temperature interaction consistent with a genotype × environment interaction was detected in addition to the population and temperature effects. This implies that not only is the digestive performance of the high-latitude population higher throughout the range of temperatures examined, but moreover the difference is reinforced at high temperatures, where the digestion rate of high-latitude fish was 1.6 times greater. Taken together, these two results provide preliminary evidence for countergradient variation in digestive rates of salmonids in response to variation in growth opportunity. The data support our previous work on the same two populations showing differences in growth rates, and underlie one of the possible mechnisms leading to more rapid growth of the high-latitude fish when both populations are reared in a common environment. 相似文献
14.
Maria Ieda Siqueira Linhares Yoshito Eizuru Gildete Patriota de Andrade Ivailda Barbosa Fonseca Luiz Bezerra Carvalho Ivanildo Tenorio Moreira Yoichi Minamishima 《Microbiology and immunology》1994,38(6):475-478
The seroprevalence of human T cell leukemia virus type 1 (HTLV-1) infection was investigated in Brazilians (570): native inhabitants (298) and descendants from Japanese (272) living in Recife and its neighborhoods—North-east of Brazil. Furthermore, polytransfused renal transplanted patients (54) were also examined for the serological status to this virus. The seropositivity to HTLV-1, screened by enzyme-linked immunosorbent assay (ELISA), was low: 1.34% for the local population and 0.73% for the descendants from Japanese. However, the seropositivity for the renal transplanted patients was found to be 11.1%. This higher value suggests that this retrovirus infection seems to be of importance in this clinical condition. 相似文献
15.
Paula Tatiana Lopes Seixas Antonio Jacinto Demuner Luiz Claudio Almeida Barbosa Cristiane Isaac Cerceau Daiane Einhardt Blank Marcelo Henrique Dos Santos Elizeu de Sá Farias Marcelo Coutinho Picanço 《Journal of Applied Entomology》2023,147(2):116-125
Aedes aegypti L. (Diptera: Culicidae) is a vector for serious diseases in tropical regions. This pest is mainly controlled by commercial larvicides but the application of such products has led to environmental problems. Essential oils (EO) have been consistently reported as molecules with insecticidal activity and can be used to produce more environmentally friendly larvicides in the control of A. aegypti. In this study, the larvicidal effect of essential oils (EO) from the leaves of three Artemisia species was evaluated against A. aegypti. The oils were obtained from steam distillation and their chemical composition was determined by gas chromatography–mass spectrometry. The EO of Artemisia camphorata was the most active in the screening bioassay and presented LC50 and LC95 of 64.95 and 74.18 μg ml−1, respectively. In addition, we found that germacrene D-4-ol was the constituent responsible for the toxicity of this EO. Artemisia camphorata EO and its major constituent, germacrene D-4-ol, are promising for the development of natural larvicides against A. aegypti. 相似文献
16.
Flavio Alexandre Carvalho Natália Valadares de Moraes Antônio Eduardo Miller Crotti Eduardo José Crevelin André Gonzaga dos Santos 《化学与生物多样性》2023,20(9):e202300492
Casearia species are found in the America, Africa, Asia, and Australia and present pharmacological activities, besides their traditional uses. Here, we reviewed the chemical composition, content, pharmacological activities, and toxicity of the essential oils (EOs) from Casearia species. The EO physical parameters and leaf botanical characteristics were also described. The bioactivities of the EOs from the leaves and their components include cytotoxicity, anti-inflammatory, antiulcer, antimicrobial, antidiabetic, antioxidant, antifungal, and antiviral activities. The main components associated with these activities are the α-zingiberene, (E)-caryophyllene, germacrene D, bicyclogermacrene, spathulenol, α-humulene, β-acoradiene, and δ-cadinene. Data on the toxicity of these EOs are scarce in the literature. Casearia sylvestris Sw. is the most studied species, presenting more significant pharmacological potential. The chemical variability of EOs components was also investigated for this species. Caseria EOs have relevant pharmacological potential and must be further investigated and exploited. 相似文献
17.
18.
Barlette Vania Elisabeth Garbujo Fábio Luiz Laurenti Freitas Luiz Carlos Gomide 《Molecular Engineering》1997,7(3-4):439-455
A five site potential model combining Lennard–Jones plus Coulomb potential functions has been developed for chloroform molecule.
The partial charges needed for Coulombic interactions were derived using the chelpg procedure implemented in the gaussian
92 program. These calculations were performed at the MP2 level with MC-311G* basis set for Cl and 6-311G** for C and H atoms.
The parameters for the Lennard–Jones potentials were optimized to reproduce experimental values for the density and enthalpy
of vaporization of the pure liquid at 298 K and 1 atm. The statistical mechanics calculations were performed with the Monte
Carlo method in the isothermic and isobaric (NpT) ensemble. Besides the values obtained for density, ρ, and molar enthalpy
of vaporization at constant pressure, Δ HV, for liquid chloroform, results for molar volume, Vm, molar heat capacity, Cp, isobaric thermal expansivity, αp, and isothermal compressibility, κT, for this pure liquid are also in very good agreement with experimental observations. Size effects on the values of thermodynamic
properties were investigated. The potential model was also tested by computing the free energy for solvating one chloroform
molecule into its own liquid at 298 K using a statistical perturbation approach. The result obtained compares well with the
experimental value. Site–site pair correlation functions were calculated and are in good accordance with theoretical results
available in the literature. Dipole–dipole correlation functions for the present five site model were also calculated at different
carbon–carbon distances. These correlations were compared to those obtained using the four site model reported in the literature.
An investigation of the solvent dependence of the relative free energy for cis/trans conversion of a hypothetical solute in
TIP4P water and chloroform was accomplished. The results show strong interaction of water and chloroform molecules with the
gauche conformer. The value obtained for the free energy barrier for cis/trans rotation in TIP4P water is higher than that
for chloroform. This result is in agreement with the continuous theory for solvation as the conformer with higher dipole moment
is more favoured by the solvent with higher dieletric constant. The results also show an increase in entropy as the solute
goes from the cis to the trans geometry and this result is more appreciable in the aqueous solution.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
19.
Izaura Yoshico Hirata Maria Helena Sedenho Cezari Clovis Ryuichi Nakaie Paulo Boschcov Amando Siuiti Ito Maria Aparecida Juliano Luiz Juliano 《Letters in Peptide Science》1995,1(6):299-308
Summary A general procedure, using the commonly employed solid-phase peptide synthesis methodology for obtaining internally quenched fluorogenic peptides with ortho-aminobenzoyl/dinitrophenyl groups as donor-acceptor pairs, is presented. The essential feature of this procedure is the synthesis of an N
-Boc or-Fmoc derivative of glutamic acid with the -carboxyl group bound to N-(2,4-dinitrophenyl)-ethylenediamine (EDDnp), which provides the quencher moiety attached to the C-terminus of the substrate. The fluorescent donor group, ortho-aminobenzoic acid (Abz), is incorporated into the resin-bound peptide in the last coupling cycle. Depending on the resin type used, Abz-peptidyl-Gln-EDDnp or Abz-peptidyl-Glu-EDDnp is obtained. Using the procedure described above, substrates for human renin and tissue kallikreins were synthesised. Spectrofluorimetric measurements of Abz bound to the -amino group of proline showed that strong quenching of Abz fluorescence occurs in the absence of any acceptor group. 相似文献
20.
Methods for the preparation of antigens from clinically isolated cultures of Aspergillus were standardized. Sera from 25 suspected cases of pulmonary aspergillosis were tested against antigens prepared by us, from 4 strains of A. fumigatus and one strain of A. flavus, using the Ouchterlony double diffusion and immunoelectrophoretic techniques.Of the 25 sera tested, 18 reacted positively with antigens of A. fumigatus, one with A. flavus and 2 with both these species. Antigens of two non-pathogenic Aspergilli included in the study failed to react with any of the sera. Our antigen preparations gave more numerous as well as sharper precipitin lines than the commercial Bencard antigens which were used for comparison. Moreover, mycelial antigens from 48 to 96 h old cultures revealed precipitin lines comparable to that of the routine, 4 week old culture filtrate antigens, thus suggesting that the incubation period for obtaining antigens could be cut down considerably.Memoir No. 323 from the Centre of Advanced Study in Botany.Deceased 相似文献