Showing papers by "University of Hohenheim published in 1976"

Isotopic tree thermometers

Abstract: Evidence is summarised here that trees store a record of atmospheric temperature in their rings. In each ring, the ratios of the stable isotopes of hydrogen and oxygen vary with the air temperature prevailing when the ring was formed. We have shown that the temperature records in three modern trees seem to follow the local mercury thermometer records, and have found that a Japanese cedar indicates a temperature fall of ∼1.5°C in the past 1,800 yr.

Die Informationsverarbeitung tympanaler Rezeptorelemente vonLocusta migratoria (Acrididae, Orthoptera)

Abstract: 1. The reactions of tympanic nerve fibers ofLocusta migratoria were recorded by glass microelectrodes in the metathoracic ganglion. 2. The units were classified by frequency-, intensity-, and directional characteristics as well as by their response pattern. The response to speciesspecific song is compared with the response to song ofEphippiger ephippiger. 3. The physiological properties lead to a classification into three types of low-frequency neurons (characteristic frequency 3.5–4 kHz; 4kHz; 5.5–6 kHz) and one type of high-frequency neuron (12–20 kHz). This is similar to other species (Gray, 1960, Michelsen, 1971). 4. Intensity-coding is done by sharp rising intensity characteristics and by different absolute thresholds of the units. 5. There is a marked directional sensitivity with some differences between LF and HF units. In the low frequency range the tympanal organ seems to react as a pressure gradient receiver; for high frequencies another mechanism is discussed. 6. No filtering of species-specific song takes place at the level of the receptor cells.

Global classification of natural terrestrial ecosystems

Abstract: A global classification system of natural terrestrial ecosystems (including systematic notation), based on the climate zones of Walter, is presented. The basic units of the system are the ecological units biome and biogeocoene. The zonobiomes, which are climate zones corresponding to the largest vegetation units, are subdivided into subzonobiomes and these into individual biomes. The biomes are thus natural, geographical units within the climate zones. They are in turn subdivided into individual biogeocoenes and their constituent synusiae. In addition, the coordinate concepts of pedobiome and orobiome are introduced. These are distinguished from the zonobiomes as follows:

Regulation of phenylalanine ammonia-lyase activity in cell-suspension cultures of Petroselinum hortense. Apparent rates of enzyme synthesis and degradation.

Abstract: The time courses for induced changes in the phenylalanine ammonia-lyase activity at five different stages during the growth cycle of cell-suspension cultures from parsley (Petroselinum: hortense Hoffm.) were investigated. Large increases in the enzyme activity, induced either by irradiation or by dilution of a cell culture into fresh medium, were followed by an exponential decline to the initial low level. The maximum inducible level of specific enzyme activity varied within a range of about six-fold, depending on the mode of induction and the growth stage of the cell culture. The general shapes of the curves for the changes in enzyme activity were similar under the various experimental conditions. However, the precise positions of the peaks in the activity varied from about 12 – 27 h after the onset of induction. Proportionally large variations were found for the peak widths at half-maximum and, in the case of induction by continuous irradiation, for the periods of time required for half-maximal induction of the system with light. The apparent half-life of the enzyme, as calculated from the rate of decline of the activity subsequent to the peak, remained approximately constant under all conditions investigated. A general model is proposed which would explain the regulation of phenylalanine ammonialyase activity in Petroselinum hortense cell cultures by an interplay of potentially large variations in the rate of synthesis and an approximately constant rate of degradation of the enzyme. This conclusion is supported both by the various experimental results and by theoretical derivations of curves for the apparent changes in the enzyme-synthesizing activity and in the rates of provision of this activity at the site of enzyme synthesis.

Abbau der 4-Chlorbenzoesäure durch eineArthrobacter-Species

Abstract: EineArthrobacter-Species, die 4-Chlorobenzoesaure als einzige Kohlenstoffquelle verwerten kann, gibt beim Wachstum auf dieser Verbindung 4-Hydroxybenzoesaure und Protocatechusaure ins Medium ab. Der weiter Abbau des aromatischen Ringes erfolgt durch “meta”-Spaltung. Beim Wachstum derArthrobacter-Species auf Benzoesaure trit im Medium cis,cis-Muconsaure auf. In diesem Fallewird also der “ortho”-Weg eingeschlagen. Die Enzyme fur beide Abbauwege sind induzierbar.

A Role for Auxin and Auxin Transport Inhibitors on the Ca Content of Artificially Induced Parthenocarpic Fruits

Abstract: Artificially induced parthenocarpic fruits of apples, pears and tomatoes, as well as seeded fruits treated with 2,3,5-triiodobenzoic acid, frequently show symptoms of Ca deficiency and a low Ca content. It was concluded that auxins, probably produced by the seeds, play a significant role in Ca translocation into fruits. Exogenous indoleacetic acid but not 4-chlorophenoxyacetic acid applications could replace the effect of seeds in this respect. Auxin transport, rather than auxin accumulation, seems to be necessary for Ca transport, as can be concluded from the effect of auxin transport inhibitors.

Der Einfluß der Kopplung von 1(n,π*)- und 1(π, π*)-Zuständen auf die Fluoreszenzfähigkeit von Azobenzolen

Abstract: Die Kopplung zwischen 1(π,π*)- und 1(n, π*)-Zustand in Azobenzolen wird durch Anderung des Energieabstandes dieser Zustande variiert. Der Energieabstand wird durch Substituenten und Losungsmittel beeinflust. Wir finden bei N-alkylsubstituierten Aminoazobenzolen und einigen Diaminoazobenzolen bei tiefer Temperatur eine schwache Fluoreszenz, die einem n π*-Ubergang zugeordnet wird. Die Fluoreszenz der Aminoazobenzole steht in engem Zusammenhang mit der sterisch gehinderter Alkylazobenzole [10]. Wir versuchen, das Auftreten der schwachen Emissionen dieser beiden Gruppen von Azoverbindungen auf die Einflusse der (n, π*)—(π, π*)-Kopplung und Veranderung der Potentialprofile bei der Photoisomerisierung durch sterische Effekte zuruckzufuhren. The coupling of 1(n,π*)- and 1(π, π)-states in azobenzenes is varied by changing their energy gap, which is possible by suitable substitution of the azobenzene and suitable choice of solvents. At low temperature we find weak fluorescence in solutions of N-alkyl substituted aminoazobenzenes and solutions of some diaminoazobenzenes. This fluorescence is assigned as of the n π*-type. The fluorescence of the aminoazobenzenes correlates with that of sterically hindered alkylazobenzenes [10]. The appearance of these weak emissions is discussed in terms of (n, π*)—(π, π*)-coupling and changes of the potential profiles of photoisomerisation by steric effects.

Mycotic Infections in Amphibians and Reptiles

Abstract: Mycotic diseases have previously been described very seldom. Only a few dozens of publications are available; compare table 1. — In the last years we could observe a few extremely interesting mycotic infections in amphibians and reptiles, four of them are discussed here.

Untersuchungen zum Abbau des Herbizids Chlorphenpropmethyl im Boden und durch Mikroorganismen

Abstract: Zusammenfassung: Das Herbizid 2-Chlor-3-(4-chlorphenyl)propionsauremethylester (Chlorphenprop-methyl) wurde in Sand-und Lehmboden bei 21°C innerhalb weniger Stunden hydrolysiert. Das Hydrolyseprodukt 2-Chlor-3-(4-chlorphenyl)propionsaure (CPP) wurde in beiden Boden bei 22.0 ppm Anfangskonzentration mit einer Halbwertszeit von 4 bis 8 Tagen. bei 4.4 ppm Anfangskonzenlralion mit einer Halbwertszeit von knapp einem Tag abgebaut. Als Zwischenprodukt des CPP-Abbaus in Boden wurde 4-Chlorbenzoesaure, in Mischkulturen von Bodenmikroorganismen ausserdem 4-Chlorzimtsaure identifiziert. Tn autoklaviertem und mit NaN3 sterilisiertem Boden unterblieb der Abbau von CPP. Die Anreicherung und Isolierung von Mikroorganismen, die den ersten Schritt des CPP-Abbaus vollziehen, war nicht moglich. Zwei aus den VersuchsbOden isolierte und vorlaufig den Gattungen Flavobacterium bzw. Brevibacterium zugeordnete Bakterienstamme bauten den Metaboliten 4-Chlorzimtsaure zu 4- Chlorbenzoesaure ab, zwei de r Gattung Arthrobacter Zugeordnete Bakterienstamme wuchsen auf der 4-Chlorbenzoesaure als alleiniger Kohlenstoffquelle. Die Ergebnisse sprechen insgesaml dafar, dass Chlorphenprop-methyl im Boden zunachst zu CPP hydrolysiert wird, welches anschliessend uber 4-Chlorzimtsaure zu 4-Chlorbenzoesaure abgebaut wird. Von der 4-Chlorbenzoesaure aus erfolgt dann weiterer Abbau unter Ringspaltung. Summary: Investigations on the breakdown of the herbicide chlorfenpropmethyl in the soil hy microorganisms The herbicide 2-chloro-3-(4-chlorophenyl)propionic acid methyl ester (chlorfenprop-methyl) was hydrolized within a few hours in sandy and loamy soils. The product of the hydrolysis, 2-chloro-3-(4-chlorophenyl)propionic acid (CPP), was metabolized in both soils with a half-life period of 4–8 days when the initial concentration was 22 ppm and of just one day when the initial concentration was 4.4 ppm. In soil 4-chloro-benzoic acid was identified as an intermediary product of the CPP breakdown, and, in mixed cultures of soil micro-organisms, 4-chloro-cinnamic acid as well, In autoclaved soil and soil sterilized with NaN3 the breakdown of CPP did not take place. The enrichment and isolation of the micro-organisms responsible for the first step in the breakdown of CPP was not possible. Two strains of bacteria isolated from the experimental soils and tentatively attributed to the genera Flavobacterium and Brevibacterium respectively, broke the metabolite 4-chloro-cinnamic acid down to 4- chloro-benzoic acid; two strains of the genus Arthrobacter grew on the 4-chloro-benzoic acid as the only carbon source. The results on the whole support the view that chlorfenpropmethyl is first hydrolized to CPP which is then broken down via 4-chloro-cinnamic acid to 4-chloro-benzoic acid. Further breakdown of 4-chloro-benzoic acid follows by ring cleavage. Resume Recherches sur la digradation de l'herbicide chlorphenpropmethyl dans le sol et par des microorganismes. L'herbicide 2-chloro, 3-(4-chlorophenyl) propionate de methyle, ou chlorfenpropmethyle, a ete hydrolyse en peu d'heures d 21°C en sol sableux et en sol limoneux. Le produit d'hydrolyse de cet ester, l'acide 2-chloro. 3-(4 chlorophenyl) propionique ou CPP, a ete degrade dans les deux sols avee un temps de demi-reaction de 4 a 8 jours pour une concentration initiale de 22,0 ppm, d'un jour tout juste pour une concentration initiale de 4,4 ppm. Comme produits intermediaires de la decomposition du CPP ont ete identifies l'acide 4-chlorobenzoique dans le sol et, en plus dans des cultures mixtes de microorganismes telluriques, l'acide 4-chlorophenylacrylique. Dans un sol autoclave et sterilisea l'aide de NaN3 il n'y a eu aucune degradation du CPP. l'enrichissement en microorganismes qui accomplissent la pemiere etape de cette degradation et leur isolement ňont pas ete possibles. Deux souches bacteriennes, isolees a partir des sols d'essai et provisoirement attribuees aux genres Flavobacterium et Brevibacterium respectivement, ont degrade le metabolite 4-chlorophenylacrylique en acide 4-chlorobenzoique. Deux souches bacteriennes appartenant selon toute vraisemblance au genre Arthrobacter, ont cru sur de l'acide 4-chlorobenzoique comme source de carbone exclusive. Les resultats d'ensemble suggerent que le chlorfenpropmethyle est d'abord hydrolyse dans le sol en CPP, lequel est a son tour degrade immediatement en 4-chlorophenylacrylate, puis en 4-chlorobenzoate. Une decomposition plus poussee du 4-chlorobenzoate implique la coupure du cycle.

Über eine dem Dicrocoelium-Befall analoge Verhaltensänderung bei Ameisen der Gattung Formica durch einen Pilz der Gattung Entomophthora

Abstract: Im Zusammenhang mit Versuchen zur experimentellen Infektion der Ameise Formica pratensis mit dem Kleinen Leberegel Dicrocoelium dendriticum wurden zahlreiche Tiere fegunden, die an dem insektenpathogenen Pilz Entomophthora sp. zugrunde gegangen waren. Die durch diese Art bei den Ameisen verursachten Verhaltensanderungen werden beschrieben und auf die gleichartigen Folgen des Pilz- und Trematodenbefalles aufmerksam gemacht. Die morphologischen Merkmale des Pilzes, der systematisch in die Nahe von Entomophthora ovispora Nowakowski einzuordnen ist, werden angegeben und die zu beobachtenden Strukturveranderungen im Gehirn der Ameisen beschrieben. Nach einem Hinweis auf die Problematik teleologischer Deutungen fur ein bestimmtes Verhalten wird abschliesend angeraten, bei der Suche nach Dicrocoelium-befallenen Ameisen auch auf eine mogliche Entomophthora-Infektion zu achten.

Makrophytische Wasserpflanzen als Bioindikatoren für Belastungen von Fliessgewässer-Ökosystemen

Abstract: In this paper a survey is given of the results of investigations concerning the problems of aquatic macrophyts as indicators of running water pollution. The following results are pointed out: 1. Dispersion pattern of macrophytic species and communities show clear relations to the water quality. That is true as well of soft running waters of the “Oberpfalzer Wald” as of the hard calcereous fen waters. 2. By the mapping of macrophytic communities floristical ecological river zones can be distinguished, frequently reflecting an exact detailed classification of the water quality. 3. That this dispersion pattern in the river is not accidental but subject to ecological regularity could be proved by transplant experiments in running waters over a number of years. 4. Putting the dispersion pattern of macrophyts in relation to single chemical pollution factors (in form of ecological series) indications for the environmental demands and the resistence of the single species can be obtained. The ecological NH4 + series in calcareous running waters indicated an ecological amplitude, differentiating within the single species. 5. To determine the tolerance of macrophyts towards single factors, an experimental aquarium plant was developed, in which a series of environmental influences can be controlled and varied. Determination methods for bioindication are referred to. 6. Finally, results of pollution experiments in aquariums ar demonstrated and their environmental significance is discussed. Submerged species show a different sensibility towards the pollution by ammonia, tensides, chlorides, heavy metals, etc.

Plasmids controlling synthesis of hemolysin in Escherichia coli. II. Polynucleotide sequence relationship among hemolytic plasmids.

Abstract: Plasmids of three different sizes, designated as plasmid A (mw: 65 X 10(6), plasmid B (mw: 41 X 10(6) and plasmid C (mw: 32 X 10(6) respectively, have been isolated from various hemolytic wild-type strains of E. coli. DNA-DNA hybridization was performed to determine their relationship. The wild-type strain, PM167a, harbours plasmids of all three sizes. Hybridization studies indicate that all three plasmids share extented sequence homologies but that plasmid A is not composed of plasmids B and C. Hybridization between plasmids of the donor strain and those of appropriate transconjugants demonstrates that in some cases plasmids with identical size are not longer completely homologous in their nucleotide sequences. This indicates that despite their defined sizes these plasmids are not stable genetic entities, but rather they undergo frequently recombination and dissociation during conjugation. In one particular transconjugant strain, K12-PM152/1, a plasmid D was found which is a stable recombined molecule of plasmids B and C of the original strain. Plasmids of size B found as the only extrachromosomal elements in a hemolytic wild-type strain (P224) and two transconjugant strains (e.g. K12-CM20 and K12-PM167/1) share extended nucleotide sequence homologies but are not identical. Little sequence homology was observed between two different hemolytic plasmids and the F and the Col Ib plasmids suggesting that the former do not belong to either the F-like or the I-like group of plasmids. Another hemolytic plasmid is F-like based on its sequence homologies with the F factor.

Beziehungen zwischen dem Ca-Gehalt bzw. der Ca Versorgung von Apfel-, Birnen- und Tomatenfrüchten und ihrem Ascorbinsäuregehalt

Abstract: A higher content of ascorbic acid of apple-, pear- and tomato fruits could be obtained by increasing the Ca concentration of these fruits. It was insignificant whether the additional Ca reached the fruit via the stalk or, after different treatments, via the cuticle. Even postharvest dipptreatments in CaCl 2-solutions improved the ascorbic acid content in the treated fruits.

Dünnschicht- und Gaschromatographie von Tocopherolen†

Abstract: Aus 1 g gefriergetrockneter Olsamen werden die naturlich vorkommenden Tocopherole und ein zugesetzter innerer Tocopherol-Standard mit einem Ultra-Turrax in 100 ml Athanol unter oxydationshemmenden Bedingungen extrahiert. Nach schonender Verseifung wird das Unverseifbare mit n-Hexan ausgeschuttelt. Der gewaschene und eingeengte Hexanextrakt wird auf Kieselgel-GF-Dunnschichten mit Dichlormethan chromatographisch getrennt. Anhand mitgelaufener Referenzsubstanzen kann naturliches oder wahrend der Analyse entstandenes Chinon erkannt werden. Die Tocopherole sind von storenden Begleitsubstanzen weitgehend befreit und konnen nach Elution unter wasserfreien Bedingungen in ihre Trimethylsilylather ubergefuhrt werden. Die Gaschromatographie (Silicongummi SE-52 + XE-60, SE-30) dieser Derivate erlaubt eine Trennung von Tocopherolen und Tocotrienolen. Trennleistung sowie gleichzeitige qualitative und quantitative, automatisierbare Bestimmung lassen die Gaschromatographie fur Routineanalysen wesentlich geeigneter erscheinen als Dunnschichtchromatographie (zweidimensional oder definierte Schichtaktivitat) mit anschliesender Kolorimetrie. Etwa 500 Einzelanalysen von Material im Bereich von 50-800 mg Lipid und 20-2000 μg Gesamt-Tocopherol/g Einwaage ergeben bei etwa 60 % Recovery einen durchschnittlichen Variationskoeffizienten von 6%. Thin-Layer end Gas Chromatography of Tocopherols Oilseeds, to which an internal standard of tocopherol was given, were extracted for tocopherols with ethanol under conditions inhibiting oxidation using an Ultra-Turrax homogenizer. After filtration the ethanolic extract is briefly saponified and the unsaponifiable matter containing the tocopherols extracted into n-hexane. Then the hexane-fraction is washed alkalifree with water, dried over Na2SO4, concentrated and applied on a silicagel GF254-plate, which is developed with dichloromethane. With co-chromatographed reference-tocopherols on the margins of the TLC-plate the presence of tocopherolquinones can be checked in UV-light, whereas the bands of tocopherols and tocotrienols are located by spraying the margins with Emmerie and Engel-reagent. The corresponding zones were scrapped off the plate, the silicagel extracted with 15 × 1 ml ethanol, the ethanol evaporated to dryness and the residue derivatised to trimethylsilylethers. Gaschromatography on 3 m SE-52/XE-60 or 1.5 m SE-30 columns gave a good separation of tocopherols and tocotrienols. Simultaneous qualitative and quantitative determination of tocopherols by GLC combined with the possibility of automation makes this analytical procedure superior to TLC and colorimetry of tocopherols. About 500 tests with different oilseeds in the range between 50-800 mg lipid and 20-2000 μg of total tocopherol/sample gave a recovery of 60% at a coefficient of variation of approximately 6%.

Sex-correlated complex heterozygosity inViscum album L.

Abstract: The nuclear dimorphism of charophytes was pointed out as early as I908 [1]. This nuclear peculiarity was confirmed by further investigations [2]. It was proved that the initial cell of the apex can give rise to two unequal daughter cells, one of which continues to divide mitotically, the other becoming amitotic. This peculiarity of giving unequipotential cells, a general property of the group, explains the alternation of nodes and internodes which is one of the main developmental features of the charophytes. Reinvestigating the nuclear dimorphism of these algae with the aid of more recent cytochemical techniques, we observed similarities between the nuclear systems of Chara (especially macronuclei) and those of several protozoa principally ciliates, first described in 1876 [3] and extensively reinvestigated in recent literature: (1) The microscopic techniques reveal that the spheroid structure of some macronuclei is very comparable, though the size and the number of chromatin granules are more variable in Chara. (2) The size ratio (30-60 x) of macronuCleus to mieronucleus is of the same order of magnitude though in charophytes the so-called micronuclei are of normal size (5-10 pm) as compared with nuclei of higher plants, thus larger than in protozoa (1.5-2 p~m). The comparison between a cortical macronucleus and a spine-cell micronucleus of the alga Chara is given in Figure 1. (3) The miDNA between micronuclei and macronuclei. In macronuclei, RNA syntheses are considerably enhanced in Chara as in ciliates. Differences between the distribution of the histone fractions exist in Chara as in ciliates, but this point is not yet clear in the alga. (6) In Chara macronuclei, in internodal as well as in cortical giant cells, we could observe \"reorganization bands\" fairly comparable with those described in ciliates. The reorganization patterns seem more complex than in protozoa though some variability has also been mentioned in ciliates. (7) The difference of behavior between both nuclei is determined by their respective positions in the cells of both organisms. Despite these evident similarities we noticed some differences between the nuclear systems of both organisms. Chara macronucleus coexists with micronucleus in the same cell, only during the mitotic division. Once separated, the new macronucleus becomes slowly giant and then, divides amitoticaUy in many karyomerites. Macronuclei are located in specific tissues and not in all cells as in ciliates. Whereas protozoan cells without micronuclei remain capable of somatic reproduction, this point has not yet been unequivoqually proved in charophytes, but recent personal experiments suggest that it may be so. It should also be kept in mind that the structural and functional similarities deal more with macronuclei. Contrary to protozoa, most of the genes of Chara micronuclei are not \"silent\". 3H uridine allowed us to demonstrate a normal synthesis of RNA, at least nucleolar RNA, which is not the case in protozoan micronucleus in which so few syntheses are detectable. In spite of the above-mentioned differences, the similarities between the nuclear dimorphism of ciliates and charophytes are striking, at the microscopic, submicroscopic, and even molecular levels. As in protozoa, Chara macronuclei can be in fact considered as an example of an amplification system of the gene activity, in some ways comparable with giant salivary-gland chromosomes of dipterae or giant lampbrush chromosomes of amphibian oocytes. The difference with these amplification systems in which only specific genes are not silent is that in Chara a large number of genes could be at work exactly as in protozoa. Despite their high level of morphologic organization, the charophytes are very ancient plants, which include a large number of extinct forms. They could be repository of a primitive but efficient amplification mechanism which they have in common with protozoa.

Einfluß von Reifedauer, Temperatur und Sauerstoffversorgung auf die Bildung von ungesättigten Fettsäuren und Tocopherolen in Sonnenblumenfrüchten

Abstract: Influence of ripening, temperature and oxygen supply on the synthesis of unsaturated fatty acids and tocopherols in sunflower seeds The ratio of vitamin E (tocopherol)/polyunsaturated fatty acids (T/PUFA) is of importance in the storage and consumption of oils and diets. In previous experiments low temperature and cool climate during seed development of sunflowers were found to decrease the T/PUFA in the seeds (Beringer and Saxena, 1968; Dompert et al., 1975). This may be due to a) a prolonged „filling period” at low temperatures and/or b) a direct effect of temperature on the synthesis of oil and tocopherol in the seeds. Harvesting sunflower seeds, grown in a climate-chamber at 22°C, at 1, 8, 15, 25, 31 and 40 days after pollination revealed an intensive lipid synthesis in the seeds between 8 and 31 days after pollination, thereafter a small decline of total lipids occured. Total tocopherols, with α-tocopherol dominating, were synthesized nearly parallel to total lipids. Accordingly a ratio of 1 mg tocopherol/g seed-oil and approximately 3–4 mg tocopherol/g linoleic acid respectively from 8 days after pollination till maturity was found. Increased growth temperatures (day and night same) from 10 to 22 up to 35°C from flowering till maturity caused a decrease in oil content and linoleic acid percentages. An attempt to compensate the stimulating effect of low temperatures on fatty acid desaturases by flushing sunflower-heads with gas mixtures of 21% O2 (10°C plants), of 28% O2 (22°C plants) and 38% O2 (35°C plants) according to Harris and James (1969) resulted in only slight increases of linoleic acid, which were with 23,5% at 35°C and 40,7% at 22°C still much lower than at 10°C, where linoleic acid was linoleic acid was 62,8% of total fatty acids. Under natural conditions a direct influence of growth temperature seems therefore more likely in determining the fatty acid composition than temperature dependant rates of O2-diffusion into the seed tissue. Unlike fatty acid synthesis the synthesis of tocopherols was not significantly influenced by the growth temperature. But due to decreasing oil content and linoleic acid percentages at higher temperatures the α-Tocopherol/g oil as well as the α-tocopherol/g linoleic acid was continuously raised. The latter increased from 0,9 at 10°C up to 7,8 at 35°C i. e., the ratio of 1 I. U. vitamin E/g PUFA required in animal and human nutrition was achieved at all temperatures tested. The parallelism of oil- and tocopherol-content in developing sunflower seeds on the one side and the large, temperature dependant variability of the T/PUFA-ratio on the other side suggest, that no „stoichiometric” relation exists between the synthesis of tocopherols and fatty acids in sunflower seeds. Fatty acid desaturases in oil seeds are membrane-bound enzymes and tocopherol might be involved as an antioxydative stabilizer of the membrane as it is known from animal tissues (McCay et al., 1971).

Notizen: Kämpferol-3-(O-sinapoylsophorosid)-7-glucosid, ein neues Flavonoid aus Brassica napus L. (Cruciferae)/Kaempferole-3-(O-sinapoylsophoroside)-7-glucoside, a New Flavonoid from Brassica napus L. (Cruciferae)

Abstract: Along with kaempferole-3-sophoroside-7-glucoside and some minor flavonoids the hitherto unknown kaempferole-3- (O-sinapoylsophoroside)-7-glucoside has been isolated from the seed of Brassica napus L. c. v. Petranova; its structure is prooved.

The Development of Pioneer — Communities on Raw Soil above Alpine Timberline (Abridged Version)

Abstract: Approximately since 1850 the glaciers are retreating their snouts towards higher elevations. This process was interrupted only by slight advances about 1890 and 1920. The areas now being ice-free offer excellent opportunities for studying plant settlement under the conditions of the alpine belt. To a certain extent the state of vegetation in this region is relevant to the origin of mud-streams and avalanches. — Up to the present the investigations of 19 forefields within the European Alps are completed.

Nuclease S1 Cleavage and the Primary Structure of Mitochondrial DNA

Abstract: The single-strand-specific nuclease S1 from Aspergillus oryzae rapidly converts superhelical mitochondrial DNA (African Green Monkey cells, Vero ATCC; CCL 81) into nicked circular DNA. These nicked mitochondrial DNA molecules contain two nicks, one in each strand. The phosphodiester backbones are cleaved during this reaction at or near sites that are alkali-labile. In a second slow reaction the circular mitochondrial DNA is converted into a linear duplex DNA. Permutation tests indicate that this linear DNA represents a nonpermutated collection of DNA molecules. These results suggest that two of the alkai-labile sites in the phosphodiester backbones of the mitochondrial chromosome are closely spaced on opposite strands and at specific positions.

Verteilung von Stickstoff auf Sproß und Wurzel bei jungen Bohnenpflanzen nach der Aufnahme von NO und NH

Abstract: Translocation of nitrogen to the shoot of young bean plants after uptake of NO and NH by the root Phaseolus vulgaris plants (var. nana, cv. Saxa) at the primary leaf stage (without nodules) were fed during 6 hours with 15NO and 15NH, respectively. 24 hours after the absorption period more 15N from the absorbed NO was translocated from the root to the shoot. The presence of NH in the nutrient solution enhanced the translocation of 15NON, probably by an inhibition of nitrate reductase. NH4-+15N is mainly retained in the root by a high incorporation into the root protein. It can be concluded that nitrogen from newly absorbed NO is not retained and used for protein synthesis in the root according to the root's potential to synthesize protein. Nitrate reduction in the root is considered to be the limiting factor. This is supported by the fact that withdrawal of NO in the nutrient solution prior to the 15N-experiment increased NOtranslocation to the shoot as a consequence of a lowered level of nitrate reductase. In an experiment with 14NOsupply to the roots and 15NOapplication to the primary leaves (infiltration method) a considerable amount of 15N was translocated from the leaves to the roots. This indicates that an insufficient NOreduction in the root can be substituted by a retranslocation of reduced N-compounds from leaves to the roots. The proportion of NO reduced in the root influences also the pattern of primary distribution of nitrogen in the shoot of plants at the 4 leaf stage. At a concentration of 0,2 meq/l NO in the nutrient solution as compared to 20 meq/l NO during 10 hours a relative higher amount of 15N was transported from the root to the younger, growing leaves i.e. via the phloem to metabolic sinks.

Über die Röntgenfluoreszenzanalyse von Aerosol-Präparaten†

Abstract: Zwei bei der Rontgenfluoreszenzanalyse von Aerosol-praparaten auftretende Probleme werden behandelt: (1) eine einfache und genaue Methode zur Herstellung von Eichpraparaten. Es wird vorgeschlagen, definierte Losungstropfen in einem exakten Punktmuster auf Filterpapier aufzubringen. (2) Die Korrektur der Streu- und Absorptionseffekte des Filters und der abgeschiedenen Schwebstoffe. Die aus Messungen in Einfach- und Dreifach-Filterpaketen gewinnbaren Korrekturterme werden am Beispiel des erfahrungsgemas kritischen Elements Calzium dargestellt. With special reference to the X-ray fluorescence analysis of aerosol samples, two problems are treated. These are, first, a simple method of preparing standards on filter paper disks (it consists of applying drops of one microlitre of solutions in an exact point raster) and second, the influence of absorption and scattering by the filter paper matrix and the aerosol layer. It is suggested to use one-layer and three-layer sample arrangements to gain corrective terms of the matrix and particle size effects.