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901.
A study was made on the phylogenetic relationships of species of the family Resedaceae, based on morphological features, chromosome meiotic behaviour, karyotype features, size and fertility of pollen grains, nucleotypic parameters, seed protein profiles and esterase isozyme patterns.For the comparison of the seed protein profiles among species a method was developed based on the presence or absence of the bands by means of a computer program. The dendrogram obtained by such a method is in line, to a great extent, with the clusters (sections) obtained within the family based on morphological features.Data on meiotic behaviour and on morphology, such as the type of fruit, carpel numbers and others, suggest that x=5 is the primitive basic chromosome number of this family. x1=6 and x2=7 are considered as secondary basic numbers derived from x=5 through aneuploid changes.The results support a proposed phylogenetic tree of the genera and sections of the genus Reseda represented in the European Flora.The principal phenomena that have operated in the evolution of the Resedaceae seem to be aneuploid changes, polyploidy and structural rearrangements. A trend towards DNA increase in the evolution of this group is also apparent. 相似文献
902.
Recombinant H-2 haplotype of mouse strain B10.D1(R108)/Y (symbol R108) obtained in experiments with skin grafting in the course of developing the CR B10.D1/Y strain (strain DBA/LacY--the donor of H-2q) was studied. Strains with recombinant H-2 haplotypes a, h2, g1, i3, i5, i7, m, y1 were used. Alleles of different H-2 (K, I, D) regions were determined according to the presence or absence of genetic complementation in the F1 test with skin grafts. R108 recombinant was studied by serological methods with panel of anti-H-2 sera. Anti-H-2Kb (H-2.33) and anti-H-2Dq (H-2.30) monospecific antisera were used in microcytotoxicity test and in absorption experiments in vitro. It was concluded that crossing over between H-2b and H-2q chromosomes, which led to formation of recombinant H-2 haplotype of R108 mice, occurred at I region, between IA and IC subregions. The H-2 complex of R108 line has KbIAbIJ?IE?ICqSqDq alleles. bq1 symbol was proposed for the H-2 haplotype of B10.D1(R108)/Y strain. 相似文献
903.
Oxygen demand and long term changes of profundal zoobenthos 总被引:3,自引:3,他引:0
Petur M. Jónasson 《Hydrobiologia》1984,115(1):121-126
The paper attempts to combine the low oxygen content of the hypolimnion during stratification and the oxygen uptake of zoobenthos. Data of declining oxygen content in the hypolimnion and critical limits of respiration are combined for Chironomus anthracinus, Potamothrix hammoniensis and three species of Pisidium, P. casertanum, P. subtruncatum and P. henslowanum. The respiratory adaptation to low oxygen content influences both growth and population dynamics of the different species. The results have important bearing on eutrophication of the Lake Esrom ecosystem and temperate eutrophic lakes in general as well as the composition of profundal zoobenthos and its population dynamics.Publication No. 389 from Freshwater-Biological Laboratory, University of Copenhagen. 相似文献
904.
M. Kopecká 《Folia microbiologica》1984,29(6):441-449
The effect of papulacandin B on regenerating protoplasts ofSaccharomyces cerevisiae was studied by light and electron microscopy. In liquid media it inhibited the biogenesis of (1→3)-β-d-glucan fibrillar nets; as a result, the protoplasts did not grow polarly but only spherically. The effect was reversible.
Instead of the nets the inhibited protoplasts synthesized only individual microfibrils soluble in hydroxide; these were not
joined in the nets and were partially masked by amorphous material. The microfibrils disintegrated after lysis and did not
maintain the shape of protoplasts. Protoplasts inhibited in solid media grew spherically up to 25 μm but they did not divide
or revert or revert, in spite of forming cell walls. These walls were amorphous and fragile and they disintegrated during
preparation. Papulacandin B did not decrease the viability of protoplasts and did not interfere with their growth, biogenesis
of alkali-soluble glucan microfibrils or amorphous wall matrix. It inhibited specifically the synthesis of alkali-insoluble
branched (1→3)-β-d-glucan, a necessary building unit required for the formation of the fibrillar component of the cell wall responsible for
the cell wall shape, its rigidity and tensile strength. 相似文献
905.
The addition of 2–4% oils to the synthetic fermentation medium used for the cultivation ofStreptomyces cinnamonensis increased the production of monensin three times on the average. When the amount of the added oil was lower than 2% and higher
than 4% the production sharply decreased. The maximal production preceded the maximal consumption of individual fatty acids
of the added oils, the content of oleic acid decreasing most pronouncedly. 相似文献
906.
Glucose inhibits the inducible synthesis of β-D-glucosidase inStreptomyces granaticolor. Neither cAMP nor cGMP influence the inhibitory effect of glucose. Glucose also inhibits the inducible synthesis of the cellobiose
uptake system but has no effect on its activity. This may be the mechanism underlying glucose inhibition of induction of β-D-glucosidase inS.granaticolor. 相似文献
907.
Managing wild crops of Gracilaria in central Chile 总被引:3,自引:3,他引:0
908.
Invertase immobilization via its carbohydrate moiety 总被引:1,自引:0,他引:1
After periodate oxidation of its glycosidic component, invertase was covalently bound onto three types of modified solid supports: glycidyl methacrylate, styrene-divinylbenzene copolymers, and bead cellulose. Direct reaction of the invertase aldehyde groups that were formed with amino groups of the support and use of the modified Ugi reaction have been employed as immobilization procedures. Apart from binding methods, the important effects of the buffer, support, conditions of periodate oxidation, and the length of the spacer on the activity of the enzyme conjugate have been investigated. Superior conjugate activity was obtained, via modified Ugi reaction, by the immobilization of a suitably oxidized invertase to a styrene-divinylbenzene copolymer having free amino groups. 相似文献
909.
Dion tomasellii sp. nov. occurs with an interrupted distribution from Guerrero to central Sonora. It is characterized by falcate to subfalcate leaflets. The populations from Sonora and northern Sinaloa are segregated asD. tomasellii var.sonorense on the basis of their narrower and glaucous leaflets. 相似文献
910.
Luis M. Vázquez de Miguel José A. Serrano Blázquez Fernando J. García Barros Manuel Gómez Guillén 《Carbohydrate research》1984,126(1):81-90
Ethyl 2-amino-4,6-O-benzylidene-2-deoxy-d-gluconate adds to acetylenic esters to give sugar enaminones. The following acetylene derivatives have been employed: methyl propiolate, ethyl phenylpropiolate, and dimethyl acetylenedicarboxylate (6). With compound 6, the reaction leads to a mixture of the expected enaminone and the isomeric oxazolidine derivative. The structures and configurations of the new compounds were studied by spectroscopic and chemical methods. 相似文献