Untersuchungen zum Einfluß des Kinetins,des Cycloheximids und des Chloramphenicols auf die lösliche Proteinfraktion von Karottengewebekulturen

Influence of kinetin, cycloheximide and chloramphenicol on soluble protein of carrot tissue cultures An application of chloramphenicol indicated that the influence of kinetin on cell division activity depends on the synthesis of proteins in cell organelles. Concurrently with the application of chloramphenicol an accumulation of proteins with relatively high electrophoretic mobility, synthesized in the cytoplasm, was observed. These protein components are preferentially synthesized after kinetin application. The influence of cycloheximide seems to be directed to the action mechanisms of IAA and inosit in the explants.     

Einfluß des Ammoniumangebotes auf Wachstum,Mineralstoff- und Polyamingehalt junger Maispflanzen

Influence of ammonium supply on growth, mineral nutrient and polyamine contents of young maize plants The influence of an increasing ammonium supply on the growth, mineral nutrient and polyamine contents of young maize plants was investigated in nutrient solution culture. A high ammonium concentration in the nutrient solution reduced shoot growth, lowered the shoot/root ratio and increased the dry matter content. The N content of the roots was increased, while the K content of the whole plant was reduced considerably. However, the plant analysis did not indicate nutrient deficiency. Ammonium nutrition induced an accumulation of putrescine in shoots and roots. None the less, regarding the ionic balance, K was only marginally substituted by putrescine, despite a close negative relationship between the putrescine and the K contents.     

Untersuchungen zur Charakterisierung des Ernährungssystems von Karottengewebekulturen: Photosynthese,Kohlenstoff- und Stickstoffernährung,Mineralstoffverbrauch

Characterization of the nutritional system of carrot tissue cultures: Photosynthesis, carbon and nitrogen nutrition, uptake of mineral nutrients During a culture period of 28 days qualitative and quantitative changes in the nutritional system of carrot tissue cultures can be observed. Investigations on sugar uptake, CO₂ fixation, and uptake of amino acids and nitrate indicate a succession of 3 periods, i.e. a heterotrophic period at the beginning of the culture period (up to 10 days), a mixotrophic period (till about the 20th day) followed by an autotrophic period. The transition into the autotrophic period could be only observed in treatments supplemented with kinetin. Uptake of potassium, phosphorus, calcium and magnesium was closely correlated to cell division activity of the explants as induced by m-inositol, IAA and kinetin.     

Zur Interpretation erhöhter Schluffgehalte in Böden des Bayerischen und des Oberpfälzer Waldes

On the interpretation of raised silt contents in soils of the Bavarian and Upper Palatinate Forest For the Bavarian and Upper Palatinate Forest (Bavaria), 41 representative pedons were examined for aeolian components using grain‐size analysis. Soils derived from loess (three pedons) are only available in the foreland of the Bavarian Forest near to the river Danube. Soils with aeolian fractions (one pedon) also exist in the adjacent part of the Bavarian Forest. No indication for loess components (37 pedons) were found in all other parts of this mountain range: these soils are missing a coarse‐silt maximum in their upper layer as should be expected for loess‐influenced soils. However, 17 of these pedons have a medium‐silt maximum in their upper layer interpreted as a result of intense physical weathering. Therefore, the widely occurrence of soils with aeolian components cannot be confirmed for this low‐mountain range of E Bavaria.     

Calciumgehalte in Früchten von Paprika,Bohne, Quitte und Hagebutte im Verlauf des Fruchtwachstums

Calcium content in fruits of paprika, bean, quince and hip during fruit growth The Ca content and the Ca translocation into the fruits during their growth was determined in paprika and bean under controlled conditions (nutrient solution, growth room) and in quince and hip (Rosa rugosa Thumb.) under field conditions. Compared to leaves the Ca content in the fruits is very low in all 4 species and declines further during their growth. The K content, however, is similar in the leaves and in the fruits of all 4 species and remains nearly constant during fruit growth. The low Ca content of the fruits cannot directly be related to the cation exchange capacity (CEC) as there are no differences in the CEC between leaves and fruits. The generally low Ca content of the fruits and its decline during fruit growth is causally related in all 4 plant species to the low rate of Ca translocation compared to the rate of dry matter translocation into the fruits. There are, however, distinct differences between the 4 plant species in the course of the ratio Ca/dry matter translocation into the fruits: In paprika the Ca translocation into the fruits strongly declines during fruit growth and in bean the Ca translocation practically ceases with the onset of seed growth. In quince under field conditions the Ca translocation into the fruits rapidly declines at later stages and finally a translocation of Ca out of the fruit takes place (decrease in the amount of Ca/fruit). Only in hip the Ca translocation into the fruits remains constant during fruit growth. There is, however, a distinctly different distribution of Ca to the various parts within the hip fruits. The decline in Ca translocation during fruit growth can be explained in paprika and bean with a shift in water influx from the xylem (rich in Ca) to the phloem at the stage of high rates of dry matter influx into the fruit. In quince and hip, however, additional mechanisms (alternating water flux in the xylem, CEC) seem to be involved in the regulation of the Ca content of these fruits.     

Ökochemische Kennwerte des Bodens

Eco-chemical parameters of soils Parameters are described which allow the ecochemical characterization of the mineral substance, of the pool of mobilizable surface bound ions, and of the pool of dissolved ions. In the soil solution (dissolved ion pool) distinction is made between parameters quantifying nutrient and acid stress and indication parameters. Indication parameters, which are derived from the anion composition of the dissolved ion pool, allow the identification of the anion source. Anion sources may be located in the ecosystem itself (HCO₃^?, NO₃^?, organic anions), may be atmospheric deposition (SO₄^2?, NO₃^?, Cl^?) and may originate from fertilization.     

Die Heterogenität des Nitratgehaltes in den Profilschichten einer Ackerbraunerde zu Beginn des Frühjahrs

Heterogeneity of Nitrate Contents in an Eroded Soil profile at the Beginning of Spring The aim of this study was to determine the variability of nitrate in a soil. Before the spring a homogeneous soil (1U from Loess, Alfisol) was sampled at 16 points in a 4 × 5 m grid. One soil probe was taken in 6 increments to a depth of 100 cm. The sum of nitrate-nitrogen in the depth increments covered a range from 99 to 166 kg NO₃-N/ha, the mean was 123 ± 20 kg NO₃-N/ha. On this basis the derived number of required cores was 9 probes.     

Wirkung des Mikroreliefs auf die räumliche Variabilität des Kohlenstoffgehaltes eines Podzoluvisols in einem Dauerdüngungsversuch

Effect of microrelief on the spatial variability of carbon content of a Podzoluvisol in a long term field trial The relationship between microrelief and spatial distribution and variability of the soil C_t-content was investigated in a long term field experiment with different fertilizer and herbicide treatments near Moscow. Only 20% of the C_t-variability were related to agricultural factors. In order to analyse the influence of the microrelief on soil C_t-content the relief was formalized. This formalization included the calculation of the local inclination, local water gathering area and local relative intensity of the temporary water streams, while distinguishing between convex and concave relief forms. Relief forms of different order were identified by kriging with different distances between the block centers. The parameters of the formalized relief were compared with the C_t-content of the soil by means of semivariograms and correlations. Through combination of relief parameters, it was possible to divide the field into different elements characterized by different correlations and effect types. The water gathering relief forms with maximal values of the relative intensity of the water streams and the arched forms with increasing intensity reduced soil C_t-content. C_t-accumulation occurred at transit positions between the convex and concave relief forms with medium intensity.     

Nitrifikation von Gülle-N in Abhängigkeit von Ausbringungstermin,pH-Wert des Bodens und Dicyandiamidzusatz

Nitrification of slurry N as dependent on application time, soil pH and addition of dicyandiamide Formation of nitrate after slurry application was investigated in relation to soil pH and dicyandiamide application in model trials at simulated outdoor temperatures of October or November till July. In the soil of pH 5.7, a supplement of 20 mg/kg DCD to slurry applied in October was sufficient to remarkably reduce nitrification which started not before March. In the soil of pH 7.2, formation of nitrate without DCD mainly occurred before winter, but was retarded by 20 mg/kg DCD till April/May. Higher amounts of DCD further delayed nitrification for about another month. After slurry application end of November (soil temperature 0°C), nitrification was retarded by dicyandiamide for up to 3 month.     

Darstellung des Bodengefüges durch Röntgenanalyse

Characterization of soil structure by X-ray analysis Frequently the use of morphological observation of soil structure to assess effects of tillage operations has been restricted by the extreme slowness of sample preparation. A method for rapid analysis of structure with the help of X-ray radiographs is described. The method is based on differences in attenuation of transmitted X-rays by soil pores and the adjoining soil mass. After digitizing X-ray pictures of unimpregnated soil cores using a video scanner and digitizer we found a close relationship between the average bulk density of soil within a core and the mean greylevel value of the digital image when sample thickness, origin and organic matter content of soil material, energy of radiation and sensitivness of X-ray film are the same. Application of a universal image processing system (DIAS) for the quantification of image parameters by procedures of binarization, skeletonization and direction coding demonstrated that radiographs are useful for analyzing spatial distribution, shape and orientation of soil structure elements. Results are illustrated by examples of soil tillage experiments.     

Eigenschaften,Entwicklung und Wert rekultivierter Böden aus Löß im Gebiet des Rheinischen Braunkohlen-Tagebaues

Conditions, genesis and value of recultivated loess soils Physical, chemical, microbiological and micromorphological investigations have been executed on recultivated loess soils deposited between 1963 and 1968 and under agriculture since than. The main results are: 1. Dry deposited materials are often strongly compressed at 50-120 cm depth. Wet and dry deposited materials may be compressed at 30-50 cm by tillage. 2. The new soils show already a notable carbonate metabolism, loss of sodium and magnesium and a certain enrichment of humus and potassium. 3. Well recultivated soils are forming fertile Pararendzina soils, whereas the other ones are developing into difficult Pseudogley soils. 4. Land evaluation gives values of 60 to 80. However, fertility is not as high, and 10-15 should be subtracted from the values. 5. In compressed soils, melioration by deep loosening and drainage is the only method to evoid further degradation. It is, however not free from difficulties.     

Untersuchungen über den Einfluß des Kinetins und des Eisens auf den Nukleinsäure- und Proteinstoffwechsel von Karottengewebekulturen

The Influence of Kinetin and Iron on Nucleic Acid and Protein Metabolism of Carrot Tissue Cultures Carrot-root tissues cultured in a nutrient solution containing Kinetin had a high rate of cell division, that led to an undifferentiated callus, and a relatively low DNA content per cell. The same tissues growing without Kinetin had a smaller rate of cell division and a higher DNA content, and showed the ability to form roots. By addition of ³²P to the nutrient solution, the cultures growing with Kinetin showed a higher specific activity of DNA than those growing without Kinetin. From previous experiments and results of other workers the possibility of the occurence of a metabolic labile DNA fraction in the cultures which grew without Kinetin is discussed. A comparison between the influence of iron and Kinetin on cell division activity, root formation, DNA, RNA and amino acid content of the tissue cultures was made on a cell basis. Iron deficiency or absence of Kinetin in the nutrient solution reduced the cell division activity of carrot tissue cultures and increased the content of DNA, RNA and soluble amino acids. The protein content was reduced by iron deficiency but was increased by the absence of Kinetin. Cultures, growing without Kinetin were able to form roots, while those, growing in an iron deficient medium were unable to show the latter phenomenon.