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101.
102.
Barley embryos were treated by 0.1% colchicine for 30 min. Samples of root tips were fixed after 4 h, 8 h and 12 h. In the first sample,c-metaphases, normal metaphases and anaphases were present jointly. Inc-metaphases, chromosomes sometimes tended to make two groups with 7 chromosomes in each. In anaphases, lagging chromosomes, tripolar and multipolar anaphasos were found. No chromosomal aberrations were detected in anaphases and metaphases. No chromosome disturbances were found in root tips sampled 8 h and 12 h after colchicine treatment. 相似文献
103.
In total 73 species of Euglena were ordered according to their saprobic index (S) and saprobic valency starting with species tolerating a heavy organic pollution and ending with those from most clean water. This paper is meant as an addition to the Ergebnisse der Limnologie, Heft 7 (Sládeek, 1973). 相似文献
104.
Adiaspiromycosis was identified in 6 animals in the examination of the lungs of 90 large carnivores. Emmonsia crescens (Chrysosporium parvum var. crescens) was demonstrated as the causative agent in 5 cases of disease — in the badger (Meles meles), the otter (Lutra lutra) and the fox (Vulpes vulpes). E. parva was demonstrated in the remaining case of disease in a fox. The badger is a new, up to the present unknown host of E. crescens. The sporadic occurrence of adiaspiromycosis in the fox and the otter classifies this disease among rare diseases of these animals. 相似文献
105.
The influence of pretreatment with exogenous DNA on the frequencies of aberrations induced by X-Rays
Pretreatment with calf thymus DNA decreases the frequency of chromosomal aberrations in metaphases and anaphases induced by X-rays in barley root meristem cella. This effect is manifested in a wide range of concentrations (5% -0.001%) without any great dependence on the concentration. Calf thymus DNA alone does not induce any chromosomal aberrations in barley root meristem cells. 相似文献
106.
Jlřina DvOřáková-Hladká 《Biologia Plantarum》1976,18(3):214-220
The paper deals with the problem of the significance of Ca2+ for the growth of algae, its participation in the process of nitrate and ammonium nitrogen utilization, and with the possibility of substituting Sr2+ for it. It was revealed that calcium represents a microbiogenous element for the algae tested, which takes part in the utilization of nitrate nitrogen. It cannot be replaced by strontium especially at a high growth rate of mixotrophically cultivated algae (ina glucose medium). 相似文献
107.
Summary Uptake and incidence of microperoxidase (Sigma) in the rat ova during cleavage at the 1-, 2-, 8-cell and blastocyst stages were studied after 30 min incubation with the enzyme (molecular weight of 1,900 and size of molecule of 2 nm).Evidence was furnished of the presence of a small amount of reaction product of microperoxidase in the zona pellucida and its local concentration in some parts of the perivitelline space. The larger part of surface of the ovum, however, was free of microperoxidase. In the cytoplasm microperoxidase was found in pinocytotic vesicles, less frequently in large vacuoles and starting with the eight-cell stage in secondary lysosomes. The largest amount of microperoxidase was ascertained at the stage of blastocyst, chiefly in the cells of the trophoblast. In the cells of the embryoblast, on the contrary, microperoxidase was found but occasionally. The reaction product of microperoxidase was also present in the intercellular space of ova in negligible amount, and likewise on the side of blastocysts' cavity. In comparison with the ingestion of horseradish peroxidase the incidence of microperoxidase in the segmenting rat ova was less frequent. 相似文献
108.
Ultrathin sectioning of submerged mycelium of Claviceps purpurea Tul. producing clavine alkaloids revealed yeast-like budding resulting in asexual sporesblastospores. These deciduous spores were born by extended hyphal cells and retained the same ultrastructure of cell organelles. Both the extended hyphae and the blastospores resembled the cells of ergot sclerotial tissue. A surface culture of C. purpurea Tul. producing no alkaloids was used as a reference. 相似文献
109.
Barley seeds were treated for 3 h at 25°C with 240 mM ethyl methanesulphonate (EMS), washed for 18 h, treated with various concentrations of unbuffered sodium azide (pH 6.7–7.3) for 3 h at 25°C, re-dried to 30% water content and either sown immediately or stored at 25°C for 12 days and then sown. The synergistic action of sodium azide post-treatment has been demonstrated only for the EMS-induced M1 germination reduction, while the EMS-induced M1 sterility and the yield of M2 chlorophyll mutants were unaffected. The ?storage” recovery from EMS-induced mutagenic effects was insensitive to sodium azide post-treatment. The 12 day-seed storage at 25°C brought about an improvement of M1 germination, M1 survival, M1 fertility and a decrease in the amount of M2 mutants, regardless of whether sodium azide post-treatment was applied or not. 相似文献
110.
Summary A population sample of 416 unrelated donors from eské Budjovice (southorn Bohemia) was investigated for the phenotypes of phosphoglucomutase (PGM). The calculated frequencies of the allelles PGM
1
1
and PGM
1
2
, 0.770 and 0.230, respectively, correspond to the expected frequencies of the phenotypes PGM 1=0.593, PGM 2-1=0.354, and PGM 2=0.0529. No rare phonotype was detected. 相似文献