Suppression of methane oxidation in aerobic soil by nitrogen fertilizers,nitrification inhibitors,and urease inhibitors

Concentrations of CH₄, a potent greenhouse gas, have been increasing in the atmosphere at the rate of 1% per year. The objective of these laboratory studies was to measure the effect of different forms of inorganic N and various N-transformation inhibitors on CH₄ oxidation in soil. NH ₄ ⁺ oxidation was also measured in the presence of the inhibitors to determine whether they had differential activity with respect to CH₄ and NH ₄ ⁺ oxidation. The addition of NH₄Cl at 25 g N g^-1 soil strongly inhibited (78–89%) CH₄ oxidation in the surface layer (0–15 cm) of a fine sandy loam and a sandy clay loam (native shortgrass prairie soils). The nitrification inhibitor nitrapyrin (5 g g^-1 soil) inhibited CH₄ oxidation as effectively as did NH₄Cl in the fine sandy loam (82–89%), but less effectively in the sandy clay loam (52–66%). Acetylene (5 mol mol^-1 in soil headspace) had a strong (76–100%) inhibitory effect on CH₄ consumption in both soils. The phosphoroamide (urease inhibitor) N-(n-butyl) thiophosphoric triamide (NBPT) showed strong inhibition of CH₄ consumption at 25 g g^-1 soil in the fine sandy loam (83%) in the sandy clay loam (60%), but NH ₄ ⁺ oxidation inhibition was weak in both soils (13–17%). The discovery that the urease inhibitor NBPT inhibits CH₄ oxidation was unexpected, and the mechanism involved is unknown.     

Süßwasser-Algenarten in Einzeldarstellung

Zusammenfassung Aus in Kuba gesammeltem Algenmaterial mit sterilenMougeotien konnte in Kulturen eine durch reichliche Sporenbildung ausgezeichnete, zunächst unbestimmbare Form isoliert werden. Nach zweijähriger Kultur erst fand sich auch Zygosporenbildung, sie zeigte, daßMougeotia abnormis Kisselev vorliegt, die damit erstmals in Kuba gefunden wurde. Die Beobachtungen legen eine Deutung der Sporen als Parthenosporen nahe, die aber bemerkenswerterweise nur aus weiblichen Gameten zu entstehen scheinen. Die korrekte Benennung der typusart der Sektion wird diskutiert und durch umfangreiche Messungen die Größenvariabilität der vorliegenden Population geprüft. Aus einer kritischen Würdigung der für die drei bisher in der Sektion beschriebenen ArtenM. abnormis, M. floridana, M. poinciana genannten Merkmale geht hervor, daß nur eine Art anerkannt werden sollte, innerhalb derer lediglich eine Varietätmajor durch dicke Fäden ausgezeichnet, unterschieden bleibt (=M. poinciana Transeau). Dazu kommt als zweite, gut charakterisierte ArtM. djalonensis Gauthier-Lièvre 1965 aus Afrika.

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Monographs of freshwater algae

Summary In cultures from Algae collected in Cuba 1968 we foundMougeotia abnormis Kisselev, new for the island. According to our observations the asexual reproductive bodies are Parthenospores. It is interesting to see that they are to be found in the female thalli, suggesting that in this species only the female gametes can undergo parthenogenetic development. A critical re-examination reveals that from the species described hitherto in the Sect. Plagiospermum:M. abnormis, M. floridana, M. poinciana, differing in no other features than in size, only oneM. abnormis Kisselev, the type species of the Section should be maintained M. poinciana may be upheld as a variety major ofM. abnormis. A second species, new described in 1965,M. djalonensis Gauthier-Lièvre from Africa is well characterized and not under consideration here.

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Mougeotia , . Mougeotia abnormis Kisselev; ¶rt; . , . . ,M. abnormis, M. floridana M. poinciana, , , , major, (=M. poinciana Transeau). , M. djalonensis Gauthier-Lièvre 1965 .

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Ergebnisse der 1. Kubanisch-Deutschen Alexander-von-Humboldt-Expedition 1967/68, Nr. 20.     

The evolution of weed beet in sugar beet crops

Summary The extent of the weet beet problem in Eastern England is described and the factors to the evolution of weed beet are outlined. Some preliminary experiments designed to distinguish between wild, weed and cultivated populations of beet are described. The response of salt (sodium chloride) solution is a potentially useful discriminating character whereas variation in morphometric characters was not so conclusive. Preliminary results on variation in cytological characters suggest that chiasma frequency is lower in weed than in wild populations and cultivars ofBeta vulgaris. Finally the possible role of crop-related weeds in breeding is discussed.

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Die Evolution der Unkrautrüben in Zuckerrübenbeständen

Zusammenfassung Es wird die Verbreitung des Problems der Unkrautrüben im östlichen England beschrieben und die Faktoren, die die Evolution der Unkrautrübenpopulation beeinflussen, werden umrissen. Einige vorläufige Versuche zur Unterscheidung zwischen Wild-, Unkraut- und kultivierten Populationen werden beschrieben. Die Reaktion auf Salzlösung (Natriumchlorid) zeigte sich als eine brauchbare Trennmethode, während die Variation in der morphometrischen Charakterisierung nicht so überzeugend war. Vorläufige Ergebnisse über die Unterschiede in der cytologischen Charakterisierung weisen darauf hin, daß die Chiasmafrequenz in Unkrautrüben geringer ist, als in Wildpopulationen und Kultursorten vonBeta vulgaris. Abschließend wird die mögliche Bedeutung der den Kulturpflanzen verwandten Unkräuter für die Züchtung diskutiert.

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Beta L. ë

Beta ë , . , , . ( ) , . , ë , Beta vulgaris. , .

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We are deeply impressed by the untimely death of Dr. A. Evans. The editors.     

Über intrazelluläre Stabbildungen (Trabeculae) im Holz als anatomische Eigenart bei Gehölzen exponierter Gebirgslagen

Zusammenfassung An zahlreichen Standorten in exponierten Hochlagen der Alpen nahe der klimatischen Baumgrenze entnommene Holzproben (Aststücke) verschiedener Holzarten ergaben eine wesentlich größere Häufigkeit von intrazellulären Stäben (Trabeculae, Sanio'sche Balken) als entsprechende Proben aus dem Tiefland (Umgebung von Potsdam). Holzproben aus offenen Kammlagen der Mittelgebirge (Schwarzwald, Vogesen, Harz) ergaben ebenfalls höhere Stabzahlen als die Tiefland-Proben, aber im allgemeinen deutlich niedrigere als die Proben aus der alpinen Region. Proben von hochmontanen Alpen-Standorten (1500–1800 m) entsprachen in der Stabhäufigkeit den Mittelgebirgs-Proben.Die Stabbildung wird durch Kältewirkung — wahrscheinlich durch Spät- und Frühfrost-Einfluß — auf das tätige Kambium ausgelöst. Eine einmal erfolgte Induktion einer Stabanlage in den Initialen kann lange Zeit erhalten bleiben, so daß z. T. sehr lange Stabreihen entstehen, die sich über mehrere Jahresringe erstrecken können. Holz mit reichlich Zellstäben weist häufig Gewebedeformationen auf, besonders im Frühholz. In diesen anomalen Gewebeteilen oder in ihrer unmittelbaren Umgebung finden sich besonders häufig Stabzellen, oder Stabreihen nehmen hier ihren Anfang. Die Gewebeanomalien sind als überwachsene Frostschädigungen aufzufassen, die während der Aktivitätsperiode des Kambiums eingetreten sind. Zur Morphologie der Zellstäbe werden neue Beobachtungen mitgeteilt. Zwischen Laub- und Nadelhölzern besteht ein deutlicher Unterschied in der durchschnittlichen Dicke der Stäbe und der relativen Häufigkeit der Stabreihen.

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Summary Wood samples (parts of branches) of different tree species from numerous sites in exposed altitudes near the climatic timber-line in the Alps showed a considerably greater frequency of intercellular bars (trabeculae, bars of Sanio) than corresponding samples from lowland sites (vicinity of Potsdam). Wood samples from open ridges of secondary chain of mountains in Central Europe (Black Forest, Vosges, Hercynian Forest) yielded higher bar-numbers, too, than those from the lowland, but in general definitely lower ones than samples from the alpine belt. Bar frequency in samples from upper-mountainous sites of the Alps (1500–1800 m) corresponded with those from the ridges of intermediate mountains.Formation of bars is initiated by cold effects upon the active cambium, probably by the influence of late and early frost in spring or late summer. Once an induction of bar-primordium has happend it may be conserved in the initials for long time, so that very long rows of bars may occur, extending over severeal growth rings. Woods with abundant intercellular bars frequently suffer from tissue deformations, particularly in springwood. In those anomalous tissues or their close vicinity there are uncommonly numerous bar-cells, or bar-rows are beginning there. Those tissue anomalities should be regarded as overgrown frost damages set in during the active period of cambium. There is a clear difference between deciduous trees and conifers in the average diameter of bars and relative extension and frequency of bar-rows.

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am au , ( ) . , ( ). , , , , . (1500–1800 ) , . ( ) . , , . , . ¶rt; , , , . , «» , . . .

     

A checklist of the outh Italian cultivated plants

Summary Ten collecting missions in South Italy together with an intensive study of literature sources allowed the compilation of a checklist of the cultivated plant species of south Italy. This checklist contains 540 taxa belonging to 520 different species. The alphabetically ordered articles for the taxa contain the botanical name, the plant family, Italian folk names, information about the distribution in the area referring to the regions, data on collections during our missions indicating the regions, too, details of plant uses and references to relevant, mostly Italian literature sources, including reports from our own explorations and papers based on the material collected. Three appendices provide indexes of synonyms and folk names, respectively, with reference to the accepted botanical names, and an index of families and genera. The information given in this checklist was extracted from a database of the cultivated plants of South Italy, a microcomputer-based system. The checklist is a useful tool for further plant genetic resources exploration in Italy, but may be also of interest for ethnobotanists and other researchers engaged in cultivated plants.

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Liste der Kulturpflanzen Süditaliens

Zusammenfassung Zehn Sammelreisen in Süditalien und ein intensives Literaturstudium ermöglichten die Zusammenstellung einer Liste der Kulturpflanzen Süditaliens. Diese Liste enthält 540 Taxa, die 520 verschiedenen Arten angehören. Die alphabetisch geordneten Artikel über die einzelnen Taxa enthalten den botanischen Namen, die Pflanzenfamilie, italienische Volksnamen, Verbreitung im Gebiet nach Regionen aufgeführt, Aufsammlungen während unserer Sammelreisen ebenfalls auf die Regionen bezogen, Angaben über die Nutzung der Pflanzen und Verweise auf wichtige, meist italienische Literaturquellen, einschließlich der Berichte über unsere eigenen Sammelreisen und von Arbeiten, die sich auf unserem Sammelmaterial begründen. Drei Register gestatten das Aufsuchen von Informationen in der Liste nach Synonymen bzw. nach Volksnamen, mit Verweis auf den akzeptierten Namen, und nach Familien und Gattungen. Die in der Liste enthaltene Information wurde aus einer Datenbank der Kulturpflanzen Süditaliens, einem mikrocomputer-gestützten System, ausgewählt. Die Liste kann für die weitere Erfassung pflanzlicher genetischer Ressourcen in Italien nützlich, aber auch für Ethnobotaniker und andere Wissenschaftler, die sich mit Kulturpflanzen befassen, interessant sein.

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. 540 , 520 . , , , , , , , , , , . , , . . , , .

     

Short-term nitrogen transformation rates in riparian wetland soil determined with nitrogen-15

N transformation rates in soil from a riparian wetland that receives runoff from adjacent pastoral land were investigated in a short-term (250 min), anaerobic laboratory incubation (20°C). A joint ¹⁵N tracing-isotope dilution technique was employed that used paired incubations of labelled (99 atom % ¹⁵N) NO₃^–-unlabelled NH₄⁺ and unlabelled NO₃^–-labelled (99 atom % ¹⁵N) NH₄⁺ at three N input levels (0.4, 4 and 24 g N g^–1 soil). At each N input level NO₃^– and NH₄⁺ were added in equal proportions (0.2, 2 and 12 g N g^–1 soil). Soil and gas samples were analysed after 10, 70 and 250 min, and the fate of ¹⁵N and N transformation rates were determined for each time period; 0–10 min (phase 1), 10–70 min (phase 2) and 70–250 min (phase 3). N transformation rates for all processes except gross NH₄⁺ mineralisation were very high during phase 1. Processes favoured by aerobic conditions, NO₃^– immobilisation (0–17% NO₃^– removal, 0–8.2 g N g^–1 soil h^–1), autotrophic nitrification (~2% NH₄⁺ removal, 0.58–0.88 g N g^–1 soil h^–1) and heterotrophic nitrification (11–35 g N g^–1 soil h^–1) increased with increased N input while the anaerobic dissimilatory NO₃^– reduction to NH₄⁺ process (1–6% NO₃^– removal, 0.48–0.62 g N g^–1 soil h^–1) decreased, presumably due to the oxidising effect of higher NO₃^– inputs. Denitrification (8–78% NO₃^– removal, 3.8–9.6 g N g^–1 soil h^–1) exhibited no clear trend related to N input levels. NH₄⁺ immobilisation (39–72% NH₄⁺ removal, 15–19 g N g^–1 soil h^–1) was higher than NO₃^– immobilisation. Gross NH₄⁺ mineralisation (0.27–0.80 g N g^–1 soil h^–1) was the only process not detected in phase 1 and one of few processes measurable in phases 2 or 3.     

Effects of the herbicide Topogard on soil respiration, nitrification, and denitrification in potato-cultivated soils differing in pH

We investigated the effects of Topogard 50 WP (3 kg ha^–1) on soil respiration, mineral N content, and number of denitrifying and total bacteria in four coarse-textured volcanic soils for 91 days. Topogard application decreased CO₂ evolution in acid soils (Tepedibi and Karaçakl) whereas soil respiration was initially increased in neutral and alkaline soils (Kaba and Balar). The herbicide application significantly stimulated ammonification in Kaba and Balar soils, while Tepedibi and Karaçakl soils showed significantly lower NH₄⁺-N contents than the control. The treatment inhibited the activity of nitrifying microorganisms and, thus it decreased the NO₃^–-N content in Tepedibi, Karaçakl, and Kaba soils, whereas the NO₃^–-N content was increased in Balar soil. The NO₂^–-N content of soils was not affected by the treatment. The activity of denitrifying bacteria was stimulated by the addition of herbicide in all soils, whereas the total number of bacteria was not influenced. It may be concluded that the effects of Topogard on the microbiological characteristics of coarse-textured soils are likely to be dependent on soil pH.     

The use of nitrogen-15 natural abundance and nitrogen yield of non-nodulating isolines to estimate nitrogen fixation by soybeans (Glycine max L.) across three elevations

Summary Dissimilarities in soil N uptake between N₂-fixing and reference non-N₂-fixing plants can lead to inaccurate N₂ fixation estimates by N difference and ¹⁵N enrichment methods. The natural ¹⁵N abundance ( ¹⁵N) method relies on a stabilized soil ¹⁵N pool and may provide reliable estimates of N₂ fixation. Estimates based on the ¹⁵N and differences in N yield of nodulating and non-nodulating isolines of soybean were compared in this study. Five soybeans from maturity groups 00, IV, VI, and VIII and their respective non-nodulating isolines were grown at three elevations differing in ambient temperature and soil N availability. Despite large differences in phenological development and N yield between the non-nodulating isolines, the ¹⁵N values measured on seeds were relatively constant within a site. The ¹⁵N method consistently produced lower N₂ fixation estimates than the N difference method, but only in three of the 15 observations did they differ significantly. The average crop N derived from N₂ fixation across sites and maturity groups was 81% by N difference compared to 71% by ¹⁵N. The magnitude of difference between the two methods increased with increasing proportions of N derived from N₂ fixation. These differences between the two methods were not related to differences in total N across sites or genotypes. The low N₂ fixation estimates based on ¹⁵N might indicate that the nodulating isolines had assimilated more soil N than the non-nodulating ones. A lower variance indicated that the estimates by N difference using non-nodulating isolines were more precise than those by ¹⁵N. Since the differences between the estimates were large only at high N₂ fixation levels (low soil N availability), either method may be used in most situations when a non-nodulating isoline is used as the reference plant. The ¹⁵N method may have a comparative advantage over N difference and ¹⁵N enrichment methods in the absence of a suitable non-N₂-fixing reference plant such as a non-nodulating isoline.     

Priming effects of 15N-labelled ammonium nitrate on uptake of soil N by wheat (Triticum aestivum L.) under field conditions

Summary The uptake of labelled and unlabelled N by wheat was measured in a field experiment using ¹⁵N-labelled ammonium nitrate fertilizer. The dry matter yield and N yields were significantly increased with fertilizer N application compared to those from unfertilized soil. The uptake of applied N by wheat ranged between 25 and 34%. Fertilizer N application increased the uptake of unlabelled soil N which was attributed to a positive priming effect or added N interaction. The added N interaction observed by applying 20, 60, and 120 kg fertilizer N was 11.4, 19.1, and 27.9 kg, corresponding to 26, 44 and 64%, respectively of the N taken up from unfertilized soil. The A values did not alter with the increase in fertilizer N application. The observed added N interaction may have been the result of pool substitution whereby added labelled fertilizer N stood proxy for unlabelled soil N. A significant correlation coefficient (r=0.996^**) between the uptake of soil N and the dry matter yield showed that soil N was more important than fertilizer N in wheat production.     

Effect of drying and rewetting on mineralization and distribution of bacterial constituents in soil fractions

Summary Mineralization of ¹⁴C- and ¹⁵N-labelled whole bacteria, cytoplasm, and cell walls and their distribution in different soil fractions were studied during 211 days of incubation including two drying and rewetting cycles. With any of these three soil amendments, almost 60% of C derived from cellular constituents was released as CO₂, 15% was incorporated into the living microbial biomass and 25% was distributed into protected microbial metabolites or recalcitrant microbial products. The distribution of C and N derived from the amendments in the different soil fractions showed that constituents adsorbed on fine clay (<0.2 m were more rapidly decomposed than those adsorbed on silt (50-2 ) and coarse clay (2–0.2 ), indicating a faster organic matter turnover in fine clay than in silt and coarse clay. Although alternate soil drying and rewetting cycles did not significantly affect the mineralization of bacterial constituents, the cycles did have an important effect on the size and specific activities of newly formed microbial biomass. This suggests the presence of an active and a dormant fraction of soil biomass.     

Mineralization of carbon and nitrogen from fresh and anaerobically stored sheep manure in soils of different texture

A sandy loam soil was mixed with three different amounts of quartz sand and incubated with (¹⁵NH₄)₂SO₄ (60 g N g^-1 soil) and fresh or anaerobically stored sheep manure (60 g g^-1 soil). The mineralization-immobilization of N and the mineralization of C were studied during 84 days of incubation at 20°C. After 7 days, the amount of unlabelled inorganic N in the manure-treated soils was 6–10 g N g^-1 soil higher than in soils amended with only (¹⁵NH₄)₂SO₄. However, due to immobilization of labelled inorganic N, the resulting net mineralization of N from manure was insignificant or slightly negative in the three soil-sand mixtures (100% soil+0% quartz sand; 50% soil+50% quartz sand; 25% soil+75% quartz sand). After 84 days, the cumulative CO₂ evolution and the net mineralization of N from the fresh manure were highest in the soil-sand mixutre with the lowest clay content (4% clay); 28% fo the manure C and 18% of the manure N were net mineralized. There was no significant difference between the soil-sand mixtures containing 8% and 16% clay, in which 24% of the manure C and -1% to 4% of the manure N were net mineralized. The higher net mineralization of N in the soil-sand mixture with the lowest clay content was probably caused by a higher remineralization of immobilized N in this soil-sand mixture. Anaerobic storage of the manure reduced the CO₂ evolution rates from the manure C in the three soil-sand mixtures during the initial weeks of decomposition. However, there was no effect of storage on net mineralization of N at the end of the incubation period. Hence, there was no apparent relationship between net mineralization of manure N and C.     

Effect of increasing oxygen concentration on total denitrification and nitrous oxide release from soil by different bacteria

Summary The effect of increasing oxygen concentrations (0, 5, 10 and 20 Vol% O₂) on total denitrification and N₂0 release was studied in model experiments using a neutral pH loamy soil relatively rich in easily decomposable organic matter and supplied with nitrate (300 g nitrate N/g dry soil). The sterilized soil was inoculated with three different denitrifying bacteria (Bacillus licheniformis,Aeromonas denitrificans andAzospirillum lipoferum) and incubated (80% WHC, 30°C). The gas volume was analysed for O₂, CO₂, N₂O, NO and N₂ by gas chromatography and the soil investigated for changes in ammonium, nitrite, nitrate, pH, total N and C as well as water-extractable C. WithB. licheniformis andAeromonas denitrificans total denitrification increased remarkably with increasing pO₂ as the result of intensified mineralization.Azospirillum lipoferum, however, showed the highest activity at 5 vol% O₂. WithB. licheniformis N₂O was released only in anaerobic conditions and at 5 Vol% O₂ (maximum) or 10 Vol% 02, but not at 20 Vol%, whereasAeromonas denitrificans produced N₂O only in the presence of He gas (maximum) or at 5 Vol% O₂. In contrast to these bacteria, N₂O production withAzospirillum lipoferum was restricted to 10 Vol% O₂ (maximum) and to 20 Vol% 02, with some traces at 5 vol% O₂. With a certain set of conditions, total denitrification and N₂O formation seem to be governed by the mineralization rate of the organisms in question. The increased demand for electron acceptors by a high turnover rate rather than the presence of anaerobic conditions seems to have determined the rate of denitrification.     

Seasonal changes in microbial biomass and nutrient flush in forest soils

Microbial biomass and N, P, K, and Mg flushes were estimated in spring, summer, autumn, and winter samples of different forest soils. The microbial biomass showed significant seasonal fluctuations with an average distribution of 880±270 g C g^-1 soil in spring, 787±356 g C g^-1 soil in winter, 589±295 g C g^-1 soil in summer, and 560±318 g C g^-1 soil in autumn. The average annual concentrations of C, N, P, K, and Ca in the microbial biomass were 704, 106, 82, 69 and 10 g g^-1 soil, respectively. Microbial C represented between 0.5 and 2% of the organic soil C whereas the percentage of microbial N with respect to the total soil N was two-to threefold higher than that of C; the annual fluctuations in these percentages followed a similar trend to that of the microbial biomass. Microbial biomass was positively correlated with soil pH, moisture, organic C, and total N. The mean nutrient flush was 31, 15, 7, and 4 g g^-1 soil for N, K, P, and Mg, respectively, and except for K, the seasonal distribution was autumn spring winter summer. The average increase in available nutrient due to the mineralization of dead microbial cells was 240% for N, and 30, 26, and 14% for P, K, and Mg, respectively. There was a positive relationship between microbial biomass and the N, P, K, and Mg flushes. All the variables studied were significantly affected by the season, the type of soil, and the interaction between type of soil and season, but soil type often explained most of the variance.     

Variation of seed characters in selectedVicia species

Summary The variability of 19 seed characters has been examined for 52 species of the genusVicia. Seed circumference, relative hilum length, hilum shape and lens position could be confirmed as the most relevant characters for grouping. By cluster analyses based upon them the material has been classified into 11 groups. Discriminant analyses gave 25 % misclassifications when all 19 variables were subjected to the analysis for the determination of individual seeds. A key for determination of the species has been proposed mainly by means of quantitative seed characters; dendrograms illustrate the result of the cluster analyses and seed diagrams show schematically important seed characters.

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Die Variabilität von Samenmerkmalen bei ausgewähltenVicia-Arten

Zusammenfassung Es wurde die Variabilität von 19 Samenmerkmalen bei 52 Arten der GattungVicia geprüft. Für eine Gruppenbildung bestätigten sich dabei der Samenumfang, die relative Nabellänge, die Nabelform und die Lage der Chalaza als besonders geeignet. Bei einer auf diesen Merkmalen aufbauenden Cluster-Analyse konnten innerhalb des Untersuchungsmaterials 11 Artengruppen ausgeschieden werden. Diskriminanz-Analysen unter Verwendung von allen 19 Variablen ergaben eine Fehlklassifikation beim Versuch der Zuordnung einzelner Samen in 25 % der Fälle. Ein Schlüssel zum Bestimmen der Arten vorzugsweise an Hand von quantitativen Samenmerkmalen wurde vorgeschlagen. Dendrogramme illustrieren die Ergebnisse der Cluster-Analysen und schematische Samendiagramme die Ausprägung der relevanten Samenmerkmale.

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Vicia

19 52 Vicia. : , , . , , 11 . , 19 25 % . , . , — .

     

Isoenzyme variation within the wildSecale L. species

Summary The degree of inter- and intra-specific variation in the populations of allogamous and autogamousSecale L. species was estimated in support of isoenzyme markers. Totally, 11 different species ofSecale were analysed including perennial species:S. kuprijanovii Grossh.,S. chaldicum Fed.,S. montanum Guss.,S. anatolicum Boiss., and annual species:S. silvestre Host.,S. vavilovii Grossh.,S. ancestrale Zhuk.,S. dighoricum Vav.,S. afghanicum Vav.,S. segetale Roshev.; as well as the cultivated ryeS. cereale L. cv. Dakowskie Zote. Isoenzymes were analysed in the first leaf of single young seedlings grown in controlled conditions using starch-gel slab electrophoresis technique and the electrophoretic forms of two different enzyme systems were detected: nonspecific esterases (E. C. 3. 1. 1) and peroxidase (E. C. 1. 11. 1. 7). It was found that the breeding system of rye species has a distinct affect on the isoenzyme variation in their populations. The selffertile annual species,S. silvestre, was monomorphic for both enzyme systems. A very low esterases polymorphism was also found in other autogamous species,S. vavilovii, however a similar degree of polymorphism in allogamous annual species,S. segetale andS. dighoricum, was observed. Generally, the perennialSecale species were more polymorphic than the annual ones, and the isoenzyme variation in the population of cultivated ryeS. cereale was similar to some other wild annual species. It was observed that the intra-specific isoenzyme variation inSecale was bigger than the inter-specific. Esterases electrophoretic forms showed to be very sensitive markers of variation in rye species.

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Isoenzym-Variation bei Wildarten der GattungSecale L.

Zusammenfassung Der Grad der inter- und intraspezifischen Variation in Populationen von allogamen und autogamen Arten der GattungSecale L. wurde mit Hilfe von Isoenzymmerkmalen geschätzt. Insgesamt wurden 11 verschiedene Arten vonSecale einschließlich der mehrjährigen Arten analysiert:S. kuprijanovii Grossh.,S. chaldicum Fed.,S. montanum Guss.,S. anatolicum Boiss. und die einjährigen Arten:S. silvestre Host.,S. vavilovii Grossh.,S. ancestrale Zhuk.,S. dighoricum Vav.,S. afghanicum Vav.,S. segetale Roshev., wie auch des KulturroggensS. cereale L. cv. Dankowskie Zote. Die Isoenzyme wurden am ersten Blatt junger Einzelsämlinge, die unter kontrollierten Bedingungen angezogen wurden, unter Anwendung der Stärkegel-Plattenelektrophorese-Technik geprüft, und die elektrophoretischen Formen von zwei verschiedenen Enzymsystemen wurden nachgewiesen: nichtspezifische Esterasen (E. C.3.1. 1.)und Peroxidase (E. C. 1. 11. 1. 7.). Es wurde gefunden, daß das Fortpflanzungssystem der Roggen-Arten eine bestimmte Wirkung auf die Isoenzymvariation in ihren Populationen hat. Die selbstfertile einjährige Art,Secale silvestris, war hinsichtlich beider Enzymsysteme monomorph. Ein sehr schwach ausgeprägter Esterasenpolymorphismus wurde in einer anderen autogamen Art,S. vavilovii, gefunden, jedoch wurde ein ähnlicher Grad von Polymorphismus in allogamen einjährigen Arten,S. segetale undS. dighoricum, beobachtet. Grundsätzlich waren die mehrjährigenSecale-Arten polymorpher als die einjährigen, und die Isoenzym-Variation der Populationen des kultivierten RoggensS. cereale war ähnlich der einiger anderer einjähriger Wildarten. Es wurde beobachtet, daß die intraspezifische Enzym-Variation vonSecale größer war als die interspezifische. Die esterase-elektrophoretischen Formen erwiesen sich als sehr empfindliche Indikatoren für die Variation der Roggenarten.

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Secale L.

Secale L. . 11 ; :S. kuprijanovii Grossh.,S. chaldicum Fed.,S. montanum Guss.,S. anatolicum Boiss.; : S. silvestreHost,S. vavilovii Grossh.,S. ancestrale Zhuk.,S. dighoricum Vav.,S. afghanicum Vav.,S. segetale Roshev. S. cereale L., . , , ( — ). : (. . 3. 1. 1.) (. . 1. 11. 1. 7.). , ë . S. silvestre . ,S. vavilovii, ,S. segetale S. dighoricum. , , , . Secale , . .

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Presented as poster     

Synthesis of 15N-labelled microbial biomass in soil in situ and extraction of biomass N

Summary A Pakistani soil (Hafizabad silt loam) was incubated at 30°C with varying levels of ¹⁵N-labelled ammonium sulphate and glucose (C/N ratio of 30 at each addition rate) in order to generate different insitu levels of ¹⁵N-labelled microbial biomass. At a stage when all of the applied ¹⁵N was in organic forms, as biomass and products, the soil samples were analysed for biomass N by the chloroform (CHCl₃) fumigation-extraction method, which involves exposure of the soil to CHCl₃ vapour for 24 h followed by extraction with 500 mM K₂SO₄. A correction is made for inorganic and organic N in 500 mM K₂SO₄ extracts of the unfumigated soil. Results obtained using this approach were compared with the amounts of immobilized ¹⁵N extracted by 500 mM K₂SO₄ containing different amounts of CHCl₃. The extraction time varied from 0.5 to 4 h.The amount of N extracted ranged from 27 to 270 g g^–1, the minimum occurring at the lowest (67 g g^–1) and the maximum at the highest (333 g g^–1) N-addition rate. Extractability of biomass ¹⁵N ranged from 25% at the lowest N-addition rate to 65%a for the highest rate and increased consistently with an increase in the amount of ¹⁵N and glucose added. The amounts of both soil N and immobilized ¹⁵N extracted with 500 mM K₂SO₄ containing CHCl₃ increased with an increase in extraction time and in concentration of CHCl₃. The chloroform fumigation-extraction method gives low estimates for biomass N because some of the organic N in K₂SO₄ extracts of unfumigated soil is derived from biomass.     

Über die Proteinbiosynthese und den Genetischen Code

Zusammenfassung In dieser Arbeit sind die Grundlagen der genetischen Information, deren Speicherung und ihre Realisierung in der Proteinbiosynthese zusammenfassend dargestellt. Es wurden die Struktur der Nucleinsäuren, die Replikation der DNS, neuere Ansichten über den Aufbau und die Funktion der Ribosomen sowie die einzelnen Reaktionsschritte bei der Proteinsynthese erläutert. Das letzte Kapitel enthält eine Übersicht von Ergebnissen, die sich mit der Entzifferung des genetischen Code befassen.Trotz der vielen Arbeiten, die in letzter Zeit auf dem Gebiet der Nucleinsäureforschung erschienen sind, bedarf es noch der Sammlung weiteren Tatsachenmaterials, um experimentelle Befunde und bestehende Hypothesen zu einem lückenlosen Bild zu vereinen.

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Summary In this review the basis of genetic information, its accumulation and the realization in protein biosynthesis are summarized. Structure of the nucleic acids, replication of DNA, and recent opinions of the construction and function of ribosomes as well as various steps in protein synthesis are explained. In the last chapter some results on decoding problems are given.In spite of the great number of papers published in the last time further research work will be necessary to synthesize experimental results and existing hypotheses.

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Vorarbeiten zur monographischen Darstellung von Wildpflanzensortimenten:Datura L., sectionsDutra Bernh.,Ceratocaulis Bernh. etDatura

Zusammenfassung Im Verlaufe morphologisch-systematischer und biochemischer Untersuchungen ist in Gatersleben eine größereDatura-Kollektion entstanden, die in die Genbank übernommen wurde und für die Züchtung von Arzneipflanzen sowie für die Grundlagenforschung zur Verfügung steht. Probleme der Erhaltung dieser Kollektion in der Genbank werden diskutiert. In diesem Zusammenhang werden Keimungsverhalten und Reproduktionssystem besonders untersucht.Zur Dokumentation des Materials ist seine Identifikation notwendig. Daher wurde die GattungDatura, mit Ausnahme der SektionBrugmansia, revidiert. Bestimmungsschlüssel ermöglichen die Determination bis zu den infraspezifischen Sippen.Entwicklungstendenzen innerhalb der Gattung werden aufgezeigt.

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Studies towards a monographic treatment of wild plant collections:Datura L., sectionsDutra Bernh.,Ceratocaulis Bernh. etDatura

Summary In the course of morphologic-taxonomical and biochemical studies a collection ofDatura has been brought together. The material has been incorporated into the gene bank and is available for breeding programmes in medicinal plants and for the use in basic research. Problems of maintaining of this collection in the gene bank are discussed. In this connection germination behaviour and breeding systems are studied.For the documentation of the material identification is necessary. Therefore, the genusDatura has been revised, excluding sect.Brugmansia. Keys are given for the determination of the species and also of the infra-specific taxa.Evolutionary trends within the genus are demonstrated.

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:Datura L., sectionesDutra Bernh.,Ceratocaulis Bernh. etDatura

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Use of Hungarian land-races in breeding

Summary The history of land-race utilization in Hungarian plant breeding programmes is briefly summarized with special emphasis on the potential use of Hungarian land-race collections in future breeding activities.

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Die Nutzung ungarischer Landsorten in der Züchtung

Zusammenfassung Die Geschichte der Verwendung von Landsorten in ungarischen Pflanzenzucht-programmen wird kurz zusammengefaßt. Besondere Betonung wird dabei auf den möglichen Nutzen der ungarischen Landsortenkollektion bei zukünftigen züchterischen Vorhaben gelegt.

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Einfluß einiger Klima- und Anbaufaktoren auf die Ertragsbildung der Reissorte ‘IR-8’ in Cuba II. Standweite und CO2-Assimilation

Zusammenfassung Infrarot-Gasanalyse bei der Reissorte IR-8 in Cuba bestätigte deren starke Heterogenität in der Photosynthesekapazität: Trotz gleicher Beleuchtungsstärke übertrifft die CO₂- Assimilation (je Blattflächeneinheit) in den obersten Blättern um ein Mehrfaches die der unteren Blätter.Im Pflanzenbestand übernehmen die obersten, gut mit Licht versorgten Blätter den Hauptanteil an der Stoffproduktion. Die steil aufgerichteten Fahnenblätter werden auch im dichten Bestand nicht gegenseitig beschattet und behalten ihre Photosynthese-Aktivität fast unvermindert bis zur Kornreife bei. Unterschiedliche Standweite hatte keinen Einfluß auf die einheitliche CO₂-Assimilation der Fahnenblätter.Starke Bewölkung und Regen können die Netto-Assimilation bis auf den Lichtkompensationspunkt senken und teilweise zu negativer Stoffbilanz in den Blättern führen.

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Effect of some climatic and agricultural factors on yield formation by the rice variety IR-8 in Cuba. II. Population density and nitrogen fertilization

Summary Infrared gas analysis with the rice variety IR-8 in Cuba confirmed the strong heterogeneity of photosynthesis; With equal light intensity, CO₂, net assimilation (per unit leaf area) proved to be much higher in the upper leaves than in the lower ones.Within the rice population, the upper leaves, well provided with light energy, assume the main share for dry matter production. Due to their upright position, the flag-leaves maintain high photosynthetic rates up to grain maturity, without mutual shading. Different levels of population density did not affect their uniform assimilation rate.Heavy clouds and rainfall may diminish net assimilation down to the light compensation point, and even may cause negative balance in dry matter production of the leaves.

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IR-8 . II. CO₂

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