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1.
The need for crop load reduction to improve fruit size andconsistency of cropping on plum and apricot trees is discussed. Threealternative strategies of achieving this objective are described: byinhibition of flowering, prevention of fruit set or stimulation ofincreased fruitlet abscission. Methods of achieving each of thesestrategies, by manual, mechanical or chemical means are discussed andevaluated. 相似文献
2.
3.
K Folkers T Kubiak H Stepien N Sakura 《Biochemical and biophysical research communications》1980,97(2):601-606
A new approach to the study of the molecular arrangements of proteins in membranes is described. Irradiation with visible light of native erythrocytes or washed erythrocyte membranes suspended in buffers containing a) riboflavin, fluorescein or fluorescein coupled to dextran and b) 3H-labelled tryptophan resulted in incorporation of radioactivity into the membrane proteins. Polyacrylamide gel electrophoresis of solubilized membranes followed by radioactivity measurements of the separated membrane proteins revealed that in native erythrocytes the protein components known to be located at the exterior cell surface, Band 3 and the major sialoglycoproteins became specifically labelled, whereas in washed lysed cells all of the major membrane proteins were labelled. 相似文献
4.
5.
Meira Ziv 《In vitro cellular & developmental biology. Plant》1991,27(2):64-69
Summary Vitrification-Hyperhydrous shoot development, effects the survival and quality of several micropropagated plants ex-vitro.
The leaves which are the immediate organ to be affected, exhibit abnormal morphology and physiology. Leaf malfunction is apparently
a stress response to very rich media and high relative humidity. The understanding of the underlying mechanism of vitrification
and its control in vitro can contribute to a more efficient micropropagation. Vitrification was found to be associated with
elevated ethylene production which was related to hypolignification and poor cell wall development. Liquid and low agar media
induced callose formation along with reduced and disoriented cellulose biosynthesis, manifested also in non-functioning guard
cells. Malfunctioning stomata, in addition to defective cuticle contributed to increased transpiration and desiccation of
in vitro formed leaves. The activity of various enzymes, associated with cell wall synthesis, was low and total proteins in
normal leaves was higher than in vitreous ones. Various measures were found to reduce vitrification; lowered matrix and water
potential in the medium, reduction in RH, low NH
4
+
, changes in Ca++ levels and the removal of ethylene. These measures improved leaf morphogenesis, survival and the quality of several micropropagated
plant species.
Presented in the Session-in-Depth Transition of Plants From Culture to Establishment In Vivo,“ at the 41st Annual Meeting
of the Tissue Culture Association, Houston, Texas, June 10–13, 1990. 相似文献
6.
Ufuk Gü ndü z 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1996,680(1-2):263-266
The dynamic viscosities of dilute aqueous poly(ethylene glycol) and dextran, and poly(ethylene glycol)-dextran-water solutions have been measured. The poly(ethylene glycol) and dextran samples had average molecular masses of 8000 Da and 580 000 Da, respectively. To estimate the values of viscosity of poly(ethylene glycol)-dextran-water solutions, a Grunberg like equation has been proposed which takes into account the influence of poly(ethylene glycol) and dextran concentrations. The relative errors vary between 0.76 and 11.64 in absolute value. 相似文献
7.
《Saudi Journal of Biological Sciences》2022,29(3):1644-1652
This study aimed to evaluate the efficacy of chitosan-silver nanocomposites in the treatment of experimentally infested pigeons with Pseudolynchia canariensis (P. canariensis) with evaluation of different immunological parameters before and after treatment. Therefore, fourteen birds were divided into 2 groups; group1(infested group including 12 birds) which subdivided into 6 sub-groups experimentally infested pigeons 2 pigeons each, and five group of them were treated with chitosan-silver nanocomposites and sub-group number 6 was treated with deltamethrin while, group 2 including two pigeons were kept as control negative ones. P. canariensis flies distributed under the wing and /or under the tail in infested group and these pigeons showed significantly lower RBCs and higher WBCs than that in non-infested pigeons. The cell mediated immune response against experimentally infested pigeons with P. canariensis was studied. P. canariensis infestation in pigeons have a negative impact on pigeon’s blood parameters, increase TNF-α and IL-1β cytokines levels. This study cleared out the role of P. canariensis in the induction of a case of oxidative stress indicated by high level of nitric oxide and malondialdehyde (MDA) with low antioxidant capacity in shape of reduced zinc concentration in the sera of experimentally infested pigeon. Chitosan-silver nanocomposite has a promising effect in the elimination of P. canariensis infestation in pigeons. 相似文献
8.
9.
Means to increase the reproductive capacity of Crocus sativus L., in vitro, are described. Cytokinins and auxin were found to be essential for development of bud explants. Ethylene and ethaphon pretreatments inhibited leaf development but induced corm production. Microsurgery of the apical bud combined with ethylene pretreatment increased both sprouting and corm production. 相似文献
10.
M Mahler 《Biochemical and biophysical research communications》1979,88(3):895-906
Mitochondria were isolated from the pectoralis and gastrocnemius muscles of chickens with a hereditary muscular dystrophy, and age-matched controls. In the pectoralis, for dystrophic birds aged 0.12, 0.25, 0.55, and 1.55 yr, the creatine phosphokinase activity of the intact mitochondria, expressed in terms of pellet protein, was 69%, 45%, 24%, and 13% as great, respectively, as that of the controls. The corresponding figures for the gastrocnemius were 79%, 46%, 51%, and 28%. The mitochondria from dystrophic muscles exhibited satisfactory respiratory control ratios, P:0 ratios, and state 3 respiratory rates. To check whether their apparent loss of creatine phosphokinase activity was due to the presence of increasing amounts of non-mitochondrial pellet protein, the state 3 respiratory rate was used as a mitochondrial marker; the rates per mg protein were similar in mitochondria from normal and dystrophic muscles of each age group. 相似文献