Showing papers by "University of Hohenheim published in 1981"
TL;DR: In a study using field trial data of various crops, it is shown that the widely used method of regressing the yield of a given genotype in the various environments on the respective means of all genotypes under test may be regarded as a combination of these two concepts, for coefficients of regression are almost perfectly correlated with variances, and mean squares for deviations from regression are nearly perfectly correlation with ecovalences.
Abstract: Two basic concepts of phenotypic stability are distinguished: (i) a stable genotype should have a minimal variance under different environmental conditions (‘biological concept’), or (ii) a stable genotype should show minimal interactions with environments as measured by the ecovalence (‘agronomic concept’). In a study using field trial data of various crops it is shown that the widely used method of regressing the yield of a given genotype in the various environments on the respective means of all genotypes under test may be regarded as a combination of these two concepts, for coefficients of regression are almost perfectly correlated with variances, and mean squares for deviations from regression are almost perfectly correlated with ecovalences.
209 citations
TL;DR: There is good evidence that these morphological and physiological changes observed in iron deficient sunflower roots are reflections of an effective regulatory mechanism for enhanced mobilization of sparingly soluble iron-III compounds in the rhizosphere and for iron uptake by sunflower plants.
Abstract: Typical morphological and physiological changes were observed in iron deficient sunflower (Helianthus annuus L. cv. Sobrid) roots. These changes, or so-called iron stress reactions, are exclusively confined to the root tips. Typical morphological changes included additional cell division in the rhizodermis layer and enhanced formation of root hairs, leading to an increase in root diameter (“swollen root tips”). These morphological changes were correlated with physiological changes such as increased release of protons, accumulation of phenols in the rhizodermis, and an increased ability of the roots to reduce iron-III compounds (“reducing capacity”). A marked increase in ability of the root tips to take up and translocate iron occurred simultaneously with these changes. There is good evidence that these morphological and physiological changes are reflections of an effective regulatory mechanism for enhanced mobilization of sparingly soluble iron-III compounds in the rhizosphere and for iron uptake by sunflower plants.
177 citations
TL;DR: It is assumed that triadimefon and triadimenol interfere in gibberellin and sterol biosynthesis in barley seedlings by inhibiting oxidative demethylation reactions.
136 citations
TL;DR: Preliminary experiments with sunflower in calcareous soil indicate an ecological importance of this fine regulation mechanism for plants on soil with a low iron availability, manifested in rhythmic iron stress reactions.
Abstract: Uptake and translocation of labelled iron were studied in sunflower (Helianthus annuus L. cv. Sobrid) grown in nutrient solution with low FeEDDHA concentrations during preculture. In contrast to conditions for plants adequately supplied with iron, suboptimal iron supply leads to temporary Fe stress with rhythmic rates of uptake and translocation of iron (period 2–4 days). This rhythmic behaviour of iron uptake is associated with corresponding changes in morphology (thickening of root tips) and physiology (increase in reducing capacity) of the roots. Iron stress is alleviated within less than one day if sufficient iron is available. This is indicated by normalisation of root morphology, reducing capacity and rate of iron uptake and translocation. This rhythm in iron uptake stresses the importance of rhythmic patterns of biochemical behaviour in complex biological systems. It is suggested that phytohormones are involved in the transformation of the iron nutritional status of the shoot apex into a “signal” for the uptake sites of iron in the roots. Preliminary experiments with sunflower in calcareous soil indicate an ecological importance of this fine regulation mechanism for plants on soil with a low iron availability, manifested in rhythmic iron stress reactions.
90 citations
80 citations
TL;DR: In this paper, it was shown that the rate of chelate splitting in the roots is determined mainly by the Fe nutritional status of the particular plant species but also by the cation exchange capacity of the roots.
Abstract: Using a double labelled Fe chelate (FeEDDHA) it has been possible to show that plants can take up Fe both, as an intact Fe chelate molecule and as ionic Fe after chelate splitting. The rate of chelate splitting in the roots is determined mainly by the Fe nutritional status of the particular plant species but also by the cation exchange capacity of the roots (positive correlation). While Fe stress has no influence on the rate of chelate splitting and the uptake of Fe by Fe‐inefficient plant species (corn), in Fe‐effi‐cient species (sunflower) it brings about a dramatic increase of the rate of Fe uptake following pronounced chelate splitting. This enhanced utilization of chelated Fe by Fe‐efficient plant species under Fe stress is associated with changes in root morphology (thickening of cortical cells, additional division of rhizodermis cells, increased formation of root hairs, presence of transfer cells). Physiological changes in the roots also accompany there morphological developments (increase...
76 citations
TL;DR: The effect of increasing NaCl concentrations (up to 150 mM) on growth and mineral composition of three genotypes of sugar beet (Beta vulgaris L, MONOHILL, ADA and FIA) has been studied.
Abstract: The effect of increasing NaCl concentrations (up to 150 mM) on growth and mineral composition of three genotypes of sugar beet (Beta vulgaris L., MONOHILL, ADA and FIA) has been studied. Growth was stimulated or little affected in water culture by 50 mM NaCl in all 3 genotypes. Further increase in NaCl concentration depressed growth in ADA more than in MONOHILL, whereas in FIA growth did not significantly differ from the untreated control. In all 3 genotypes, particularly in FIA, increasing NaCl concentrations decreased potassium content in the shoots more than in the fibrous and storage roots. Simultaneously, the accumulation of sodium and chloride in the shoots was considerably higher in FIA than in ADA, where in contrast larger proportions of these ions were retained in the roots. The results demonstrate considerable genotypic differences in salt tolerance of sugar beet and indicate a positive correlation between salt tolerance and accumulation of sodium and chloride in the shoots. FIA but not ADA may be suited for a breeding programme of sugar beet for improved salt tolerance.
69 citations
TL;DR: GFA expression was not reinduced in cultures that had lost the GFA marker by treatment with dibutyryl cyclic AMP, and the proliferating cultures expressed only the vimentin type of intermediate filament.
68 citations
TL;DR: In this paper, the effect of replacing 50% or 95% of the potassium by sodium on growth and on potassium and sodium levels in three genotypes of sugar beet (MONOHILL, ADA, FIA) has been studied in water culture over a period from 2 to 9 weeks.
Abstract: The effect of replacing 50% or 95% of the potassium by sodium on growth and on potassium and sodium levels in three genotypes of sugar beet (MONOHILL; ADA; FIA) has been studied in water culture over a period from 2 to 9 weeks.
In all three genotypes there was a preferential uptake of potassium compared to sodium. Nevertheless, at high sodium supply most of the potassium was replaced by sodium, particularly in the leaves. At the same supply the accumulation of sodium in the leaves increased in the following order: ADA < MONOHILL < FIA. Even with high dominance of sodium in the medium, the youngest leaves of FIA held about 0.5 mmol potassium per g dry matter, and potassium was evidently translocated from old leaves to the new growth.
Effects of sodium on growth became more important with time. After 9 weeks, 50% replacement of potassium by sodium increased growth of all plant organs of the three genotypes. Replacing 95% of potassium by sodium depressed growth of the storage root in MONOHILL and particularly in ADA, with simultaneous enhancement of leaf growth in the latter. In FIA, however, this treatment further stimulated both leaf and, particularly, storage root growth. Sodium in comparison with potassium increased the sucrose concentration in leaves and storage roots. The highest sucrose concentration in the storage roots of ADA and FIA was obtained in the treatment with 95% sodium.
The results demonstrate pronounced genotypic differences in sugar beet with respect to the response to sodium. FIA has the most natrophilic behaviour and might be a promising genotype for breeding programmes for adaptation of sugar beet plants to soils high in sodium.
64 citations
TL;DR: The C-7 benzoates of tetranortriterpenoids occurring in Azadirachta indica are described for the first time and the structures were determined by spectroscopical methods.
58 citations
TL;DR: The results explain why long-chopped silage intake is associated with pseudo-rumination, a lower breakdown of particles and a waste of digestion time.
Abstract: 1. The eating and ruminating activity of four rams given long-chopped silage ad lib. in two daily meals was studied by jaw movement recordings. The events of rumination and pseudo-rumination were observed by fluoroscopy and by cineradiography. 2. The rate of eating was highest at the beginning of the main meal and then declined gradually. 3. The silage intake level was low. 4. The swallowed silage did not accumulate at the cardiac region but was forced into the dorsal sac of the rumen by the contractions of the reticulum and cranial sac of the rumen. For regurgitation the solid particles had to return via the ventral and cranial sac of the rumen into the reticulum. 5. Liquid reticular contents with floating solid particles were aspirated into the oesophagus during the maximum of the regurgitation contraction of the reticulum. 6. The rumination activity during the day presented a high proportion of pseudo-rumination cycles whereas during the night the rumination became progressively normal. 7. Pseudo-rumination was caused by delayed return of the fibrous silage particles into the reticulum. Thus in pseudo-rumination the regurgitated material consisted predominantly of fluid containing only a small quantity of solid particles. 8. The results explain why long-chopped silage intake is associated with pseudo-rumination, a lower breakdown of particles and a waste of digestion time.
TL;DR: In this paper, the authors demonstrate that the regulatory mechanism of sunflower under iron-stress - increase in H+ efflux and reducing capacity of the roots and thus enhanced uptake of iron (and manganese) is severely inhibited or even blocked by high bicarbonate concentrations.
Abstract: In pot culture experiments using a calcareous soil the growth rate of sunflowers was depressed by latent iron deficiency. Iron-stress reactions, reflected by enhanced uptake rate of Fe-59 after short-term supply of 59FeEDDHA were observed under these conditions. These reactions, however, were delayed and much less distinct than those observed under latent iron deficiency in water culture experiments. Addition of MgCO3 to this soil increased the iron deficiency of the plants and caused chlorosis, but prevented these iron-stress reactions.
In contrast to the soil experiments, distinct iron-stress reactions could be observed with latent iron-deficiency in sand culture experiments in which varied amounts of inorganic Fe-III were supplied. These reactions were only observed, however, in absence of bicarbonate. Even 4 meq bicarbonate severely inhibited these iron-stress reactions which were almost totally inhibited at 10 meq bicarbonate. Bicarbonate depressed both short-term uptake of Fe-59 as well as total iron content of the leaves. There was no evidence for an additional “inactivation” of iron within the leaves due to bicarbonate treatment. Bicarbonate also strongly depressed the manganese content of the young leaves.
The results demonstrate that the regulatory mechanism of so-called “iron-efficient” plant species like sunflower under iron-stress - increase in H+ efflux and reducing capacity of the roots and thus enhanced uptake of iron (and manganese) - is severely inhibited or even blocked by high bicarbonate concentrations. “Lime chlorosis”, caused by high bicarbonate concentrations on calcareous substrates is therefore also widespread in so-called “iron-efficient” species.
TL;DR: In this article, the tetranortriterpenoids from Melia azedarach linn (Meliaceae) were determined on the basis of NMR, IR, and MS data.
Abstract: Die Chromatographie der Petrolether- und Ether-Extrakte aus Fruchten von Melia azedarach Linn. ergab sechs Tetranortriterpenoide 1–6, deren Konstitutionen auf NMR-, IR- und massenspektroskopischem Wege zugeordnet wurden. Oxidation des Lactols 5 lieferte das Lacton 2.1 und 2 wurden durch Methanolyse and Acetylierung in 3 bzw. 4 ubergefuhrt.
New Tetranortriterpenoids from Melia azedarach Linn. (Meliaceae)
Chromatography of the petroleum ether and ether extracts from the fruit of Melia azedarach Linn. afforded six new tetranortriterpenoids 1–6 the structures of which have been determined on the basis of NMR, IR, and MS data. Oxidation of lactol 5 gave lactone 2. 1 and 2 gave 3 and 4, resp., on methanolysis followed by acetylation.
TL;DR: In this article, the effects of NaCl and replacement of K+ by Na+ on the lipid composition of the two sugar beet inbred lines FIA and ADA were studied (a) with increasing additions of NaC to the basal medium, and (b) with an increasing replacement by NaC at the same total concentration as in the base medium.
Abstract: The effects of NaCl and replacement of K+ by Na+ on the lipid composition of the two sugar beet inbred lines FIA and ADA were studied (a) with increasing additions of NaCl to the basal medium, and (b) with increasing replacement of K+ by Na+ at the same total concentration as in the basal medium. Direct relations were noted between NaCl concentration of the nutrient solution and the phospholipid concentration in the roots of FIA, the genotype characterized by a low K+/Na+ ratio, as well as between NaCl in the medium and the phospholipid concentration in the shoots of ADA, the genotype with a high K +/Na + ratio. The sulfolipid level in the roots of FIA was maintained at higher NaCl concentrations, while it was decreased in ADA. The glycolipid concentration in the shoots of ADA and the degree of unsaturation of the fatty acids of the total lipid fraction were decreased by salinity, indicating reduced biosynthesis of chloroplast glycolipids and/or accelerated oxidation of these lipids in the presence of NaCl.
In the Na+ for K+ replacement experiment a low content of K+ in the medium resulted in decreased levels of total lipids, phospholipids and sulfolipid in the roots of both genotypes, which did not relate to root growth. K+-leakage from the roots at low K+-level in the medium may be reduced by the increase in saturation of the lipids. In the shoots of ADA increased levels of total lipids, phospholipids and Sulfolipid were noted at a low K+-concentration of the nutrient solution.
TL;DR: Prepative thin‐layer chromatography was used to isolate from embryonic chick brains four different polysialogangliosides which moved below GT1b on TLC plates, and the only accumulating ganglioside was GM1.
Abstract: Preparative thin-layer chromatography was used to isolate from embryonic chick brains four different polysialogangliosides which moved below GT1b on TLC plates. These possessed molar sialic acid-to-sphingosine ratios of 4:1, 5:1, 6:1, and 7:1, respectively. Mild neuraminidase (Clostridium perfringens) treatment of the three most highly sialylated fractions gave GT1b and GD1b transiently, but the only accumulating ganglioside was GM1. All three polysialogangliosides were also found in Elasmobranch brains. During development of he chicken the concentrations of the two most slow-moving fractions ("hexa"-, and "septa" -sialogangliosides) decreased.
TL;DR: As a hindgut fermenter, the rabbit obtains the vitamins and proteins synthesized in the large intestine by caecotrophy, i.e. the production and preferential ingestion of special soft faeces, a higher degree of specialization than coprophagy which is practised by many rodents.
TL;DR: Activity of GA's could be detected only in young fruits but not in unpollinated ovaries, and the possible relevance of these findings for tomato fruit-set is discussed.
Abstract: Levels of extractable free indolyl-3-acetic acid (IAA), gibberellin-like substances (GA's), and abscisic acid (ABA) were analysed in tomato ovaries (Lycopersicon esculentum Mill.) before pollination as well as in fruits 5 and 10 days after pollination or treatment with growth regulators to induce parthenocarpic fruit development. Growth regulators applied were a naphthoquinone (bendroquinone), an auxin (4-CPA), a morphactin (CME), and a benzothiadiazole (DU).
The initial high levels of ABA (2.7 μg/g dry weight) in unpollinated ovaries decreased to one third or less after 5 and 10 days. In contrast levels of IAA increased from 80 up to 180 ng/g dry weight. Activity of GA's could be detected only in young fruits but not in unpollinated ovaries.
The possible relevance of these findings for tomato fruit-set is discussed.
01 Jan 1981
TL;DR: In contrast to the numerous publications on uptake of radioactive strontium (85Sr, 89Sr and 90Sr) and its effects on plant growth, only a few articles exist on the uptake of stable Sr2+ and its possible effects on the plant growth as discussed by the authors.
Abstract: In contrast to the numerous publications on uptake of radioactive strontium (85Sr, 89Sr, and 90Sr) and its effects on plant growth resulting from irradiation by strontium or its radioactive daughter nuclides (e.g., Y-90), only a few articles exist on the uptake of stable Sr2+ and its possible effects on plant growth. Nevertheless there are two reasons why uptake of stable Sr2+ and its effects on plant growth are of great importance. First, from the viewpoint of plant physiology and plant nutrition it is interesting to know both the uptake and the effects of stable Sr2+ in relationship to the chemically related Ca2+. Similar study has already been carried out with other corresponding groups of ions (Li+ and Ca2+, Rb+ and K+, Br- and Cl-, or SO 4 2- and SeO 4 2- , PO 4 3- and ArO 4 3- ). With respect to the uptake and translocation of stable Sr2+ by the plant (but not with regard to its effects on plant growth), studies with radioactive strontium isotopes are very helpful. Second, from the ecological viewpoint, it is worthwhile to obtain information on regional and species differences in plant uptake and effects of stable Sr2+ on growth.
TL;DR: In this article, it is shown that the mean elevation of the watersheds in the Central Caucasus Mts. increased from late Pliocene times (Lower Akchagyl: 2000 m) to the Middle Pleistocene (Lower Apsheron: 3500 m) in recent times.
Abstract: The basis for valid paleoecological investigations is a profound know ledge of the evolution of climate. Moreover, paleoclimatological studies enable us — perhaps — to draw conclusions as to the future development of climate, provided the reasons for and the possible periodicity of changes in climate during the past are understood. So paleoclimatology has become an intensively investigated discipline. Of course it should be known whether the solar irradiance is variable or not (WILLSON et al. 1981, KERR 1982), and tectonic uplifting or down- warping may play an important role in the evaluation of possible climatic influences on the biosphere. So it is worthwhile to note that according to VOZOVIK (1976) the mean elevation of the watersheds in the Central Caucasus Mts. increased from late Pliocene times (Lower Akchagyl: 2000 m), and from the very beginning of the Pleistocene (Upper Akchagyl, 2700 m) to the Middle Pleistocene (end of the Apsheron, 3500 m), to 4400 m in recent times. The same topic has been analyzed by ALESHINSKAYA et al. (1976 a,b) in regard of the Tien Shan Mts., in connection with changes in synchronous paleoecological conditions. Other important boundary conditions are the surface areas of the inland ice-masses (for the last glaciation see DENTON and HUGHES 1981; for the whole of the Pleistocene, the continental shelf areas included: GROSVALt) 1983), as well as the changes in the CO2-content of the global atmosphere in an interglacial-glacial-interglacial cycle.
TL;DR: A coat-protein-free mutant of tobacco mosaic virus as well as mutants with a non-functional coat protein were found to interfere with the establishment and spread of challenging strains of TMV.
Abstract: A coat-protein-free mutant of tobacco mosaic virus as well as mutants with a non-functional coat protein were found to interfere with the establishment and spread of challenging strains of TMV. The results do not support an earlier concept, according to which the genome of a related challenging virus could be captured by the coat protein of the virus introduced in advance. The presence of a viral coat protein is obviously not essential and a competition among the viral genomes for some specific site seems to be a more likely mechanism of cross protection.
TL;DR: In this article, three novel tetranortriterpenoids, 3-deacetylsalannin (1a), salannol (2), and 1,3-diacetylvilasinin (3a), which show antifeeding activity towards insects, have been isolated, the structures of which have been determined particularly by NMR-spectroscopy.
TL;DR: Pentanortriterpenoids from Azadirachta indica A. Juss (Meliaceae) have been isolated for the first time from seed oil, leaves, and bark.
Abstract: Aus Samenol, Blattern und Rinde von Azadirachta indica A. Juss (Meliaceae) wurden erstmals Pentanortriterpenoide isoliert. Nimbinen (1a), 6-Desacetylnimbinen (1b), Nimbandiol (2a) und 6-O-Acetylnimbandiol (2b) finden sich im Samenol, 1a, b und 2a in den Blattern, 1a und b in der Rinde. Die Konstitutionen wurden NMR-spektroskopisch zugeordnet.
Pentanortriterpenoids from Azadirachta indica A. Juss (Meliaceae)
Pentanortriterpenoids have been isolated for the first time from seed oil, leaves, and bark of Azadirachta indica. Nimbinene (1a), 6-deacetylnimbinene (1b), nimbandiol (2a), and 6-O-acetylnimbandiol (2b) have been found in the seed oil, 1a, b and 2a in the leaves, 1a and b in the bark. The structure determination was carried out by NMR spectroscopy.
TL;DR: Under the conditions used, the capabilities of Triticum and Sorghum to induce nitrogenase activity in Azospirillum and Rhizobium were in the same range.
TL;DR: The present studies further support the idea that Tri EL is the primary derivative of TEL in illuminated algal cultures and that TriEL is the agent which causes the severe inhibitory effects in TEL toxicity to Poterioochromonas malhamensis.
TL;DR: The steady-state kinetic patterns of the bifunctional enzyme histidinol dehydrogenase from Salmonella typhimurium (EC 1.1.23) are compatible with a bi-uni uni-bi ping-pong mechanism and studies of product inhibition make it possible to determine the sequence of substrate binding and product dissociation.
Abstract: The steady-state kinetic patterns of the bifunctional enzyme histidinol dehydrogenase from Salmonella typhimurium (EC 1.1.1.23) are compatible with a bi-uni uni-bi ping-pong mechanism. Studies of product inhibition make it possible to determine the sequence of substrate binding and product dissociation. Histidinol binds first to the enzyme, followed by the binding of NAD+; histidine is the last product to dissociate from histidinol dehydrogenase. Five of ten kinetic constants defined are determined from linear intercept and slope replots; Km for histidinol was found to be 16 +/- 3 microM and for NAD+ 1 +/- 0.3 mM; K2 for NAD+ was determined to be 0.8 +/- 0.4 mM and K3 for NADH to be 0.3 +/- 0.07 mM. K1 for histidine was found to be 2.1 +/- 0.5 mM.
TL;DR: The application of fruit-thinning chemicals to ‘King of the Pippins’ suppressed the early increase of GAs in diffusates, which normally occurs during the second week after full bloom, and the thinning-treatments caused no real change in the amount of extractable GAs, which was very similar in fruits from both cultivars.
TL;DR: Using isoelectrofocusing (IEF), multiple forms of Petunia β-galactosidase activity could be detected and showed only minor tissue-specific differences, suggesting that it seems highly improbable that theβ-galactsidase pattern was due to artefacts.
TL;DR: Extrapolation of the initial part of the inactivation curve caused by pyridoxal-P indicates that modification of two essential lysine residues results in inactivation of the dimeric enzyme.
Abstract: Histidinol dehydrogenase (EC 1.1.1.23) from Salmonella typhimurium is inhibited by formaldehyde and pyridoxal 5-phosphate (pyridoxal-P). epsilon-Pyridoxyl-lysine is isolated upon acid hydrolysis of pyridoxal-P-treated enzyme reduced by sodium borohydride. In the presence of formylhistidinol and formylhistidine (specific ligands of the enzyme) inactivation of histidinol dehydrogenase by pyridoxal-P is prevented. Extrapolation of the initial part of the inactivation curve caused by pyridoxal-P indicates that modification of two essential lysine residues results in inactivation of the dimeric enzyme. The essential lysine residues appear to participate in the reversible oxidation/reduction reaction converting histidinol to histidinal.
TL;DR: From the fertile sprouts of Equisetum arvense L. have been isolated protogenkwanin 4'-glucoside and gossypitrin this article.