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  • Gas chromatography  (24)
  • Nitrogen fixation  (21)
  • Wheat
  • temperature
  • Springer  (73)
  • Periodicals Archive Online (PAO)
  • 1985-1989
  • 1980-1984  (73)
  • 1975-1979
  • 1981  (73)
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  • 1985-1989
  • 1980-1984  (73)
  • 1975-1979
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  • 1
    Electronic Resource
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    Springer
    Planta 152 (1981), S. 544-552 
    ISSN: 1432-2048
    Keywords: Ammonium assimilation ; Lichens ; Nitrogen fixation ; Peltigera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Nostoc in the cephalodia of the lichen Peltigera aphthosa Willd. fixed 15N2 and the bulk of the nitrogen fixed was continuously transferred from it to its eukaryotic partners (a fungus and a green alga, Coccomyxa sp.). Kinetic studies carried out over the first 30 min, after exposure of isolated cephalodia to 15N2, showed that highest initial 15N2-labelling was into NH 4 + . After 12 min little further increase in the NH 4 + label occurred while that in the amide group of glutamine and in glutamate continued to increase. The 15N-labelling of the amino group of glutamine and of aspartate increased more slowly, followed by an increase in the labelling of alanine. When total incorporation of 15N-label was calculated, the overall pattern was found to be rather similar except that, throughout the experiment, the total 15N incorporated into glutamate was about six times greater than that into the amide group of glutamine. Pulse chase experiments, in which 14N2 was added to cephalodia previously exposed to 15N2, showed that the NH 4 + pool rapidly became depleted of 15N-label, followed by decreases in the labelling of glutamate, the amide group of glutamine and aspartate. The 15N-labelling of alanine, however, continued to increase for a period. When isolated cephalodia were treated with L-methionine-SR-sulphoximine, an inhibitor of glutamine synthetase (EC 6.3.1.2), and azaserine, an inhibitor of glutamate synthase (EC 2.6.1.53), there was no detectable labelling in glutamine although the 15N-labelling of glutamate increased unimpaired. On treating the cephalodia with amino-oxyacetate, an inhibitor of aminotransferase activity, the alanine pool decreased. Evidence was obtained that glutamine synthetase and glutamate synthase were located in the Nostoc, and that glutamate dehydrogenase (EC 1.4.1.4) and various amino-transferases were located in the cephalodial fungus. Possible implications of these findings are discussed.
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  • 2
    ISSN: 1432-072X
    Keywords: Nitrogen fixation ; Regulation ; Guanosine 5′-diphosphate 3′-diphosphate (ppGpp)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Addition of ammonium to N2 fixing cultures of Azotobacter vinelandii, Klebsiella pneumoniae and Clostridium pasteurianum rapidly reduced the intracellular levels of guanosine 5′-diphosphate 3′-diphosphate (ppGpp) by 70–90%. This change might reflect a regulatory role of ppGpp in nitrogen metabolism.
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  • 3
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    Archives of microbiology 129 (1981), S. 238-239 
    ISSN: 1432-072X
    Keywords: Rhizobium ; Disaccharide ; Bacteroid ; Transport ; Nitrogen fixation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Slow growing strains of rhizobia appear to lack both uptake systems and catabolic enzymes for disaccharides. In the fast-growing strains of rhizobia there are uptake mechanisms and catabolic enzymes for disaccharide metabolism. In Rhizobium leguminosarum WU 163 and WU235 and R. trifolii WU290, sucrose and maltose uptake appears to be constitutive whereas in R. meliloti WU60 and in cowpea Rhizobium NGR234 uptake of these disaccharides is inducible. There is evidence that there are at least two distinct disaccharide uptake systems in fast-growing rhizobia, one transporting sucrose, maltose and trehalose and the other, lactose. Disaccharide uptake is via an active process since uptake is inhibited by azide, dinitrophenol and carbonyl cyanide m-chlorophenylhydrazone but not by arsenate. Bacteroids of R. leguminosarum WU235 and R. lupini WU8 are unable to accumulate disaccharides.
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  • 4
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    Archives of microbiology 130 (1981), S. 38-43 
    ISSN: 1432-072X
    Keywords: Nitrogen fixation ; Gene expression ; Regulation ; Messenger RNA ; Transcription ; Klebsiella pneumoniae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Nitrogenase messenger RNA synthesis in Klebsiella pneumoniae was determined by labelling cells with (3H)uracil and isolating total RnA, which was then hybridized to filterbound recombinant plasmid pSA30 DNA carrying the nitrogenase structural genes nifH, D, and K. Derepression of nitrogenase mRNA starts 1.5 h before the onset of nitrogenase activity (as measured by acetylene reduction). Exposure of nif-derepressed cultures to either NH 4 + , air, or high temperatures (39° C) results in a rapid decrease of the synthesis rates both of nitrogenase mRNA and nitrogenase polypeptides. Nitrogenase mRNA is remarkably stable. After blocking transcription with rifampicin, hybridizable and actively translatable nitrogenase mRNA survives with an average half-life of 18 min. Half-lives are considerably shorter when rifampicin-inhibited cultures are simultaneously shifted to conditions which are non-permissive for nitrogenase synthesis, pointing to some posttranscriptional influence on nitrogenase mRNA stability. In all experiments performed there was no evidence for uncoupling of nitrogenase mRNA synthesis from nitrogenase mRNA translation, indicating that nitrogenase synthesis is regulated solely by transcriptional control.
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  • 5
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    Archives of microbiology 130 (1981), S. 96-100 
    ISSN: 1432-072X
    Keywords: Nitrogen fixation ; Nitrate respiration ; Denitrification ; Assimilatory nitrate reduction ; Dissimilatory nitrate reduction ; Acetylene reduction ; Azospirillum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Azospirillum spp. participate in all steps of the nitrogen cycle except nitrification. They can fix molecular nitrogen and perform assimilatory nitrate reduction and nitrate respiration. Culture conditions have been defined under which nitrate is used both as terminal respiratory electron acceptor and as nitrogen source for growth. Nitrate and, possibly to a very limited extent, nitrite, but not sulfate, iron or fumarate support anaerobic respiration. Under anaerobic conditions, nitrate can also supply energy for nitrogen fixation but without supporting growth. Nitrate-dependent nitrogenase activity lasts only for 3–4 h until the enzymes of assimilatory nitrate reduction are synthesized. Nitrite accumulates during this period and inhibits nitrogenase activity at concentrations of about 1 mM.
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  • 6
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    Theoretical and applied genetics 59 (1981), S. 145-152 
    ISSN: 1432-2242
    Keywords: Wheat ; Frost resistance ; Diallel cross ; F2monosomics ; Substitutions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Genetic studies of frost resistance were performed on various wheat varieties using diallel, F2 monosomic and substitution analysis. A six-parental cross including reciprocals was carried out, and F1 hybrids and their parents were used for the freezing tests under controlled conditions. Both the general combining ability (GCA) and the specific combining ability (SCA) were significant, indicating additive and non-additive gene action in the inheritance of frost resistance. The high GCA∶SCA ratio revealed a preponderance of additive genetic variance. No significant reciprocal differences were found between the reciprocal crosses. The variance/covariance graphical analysis indicated the partial dominance of frost sensitivity. Frost sensitive varieties had the largest number of dominant genes, while frost resistant varieties had the highest proportion of recessive genes. The magnitude of the additive component of variation was higher than that of the dominance component, and the overall measure of the degree of dominance was smaller than one, so average dominance is incomplete. The increasing and decreasing alleles are not equally frequent at all loci. In this set of wheat varieties the values of narrow and broad heritability are relatively high. F2 monosomic analysis of the winter wheat variety ‘Arthur’ crossed with the monosomics of ‘Chinese Spring’ revealed that the average frost resistance of all the 21 monosomics was lower than that of the disomic. F2 monosomic hybrids 5A, 2B, 4B and 5D proved to be relatively frost resistant, while monosomics 3A, 3B and 6D were the most sensitive. The control of frost resistance in the set of chromosome substitution lines of the variety ‘Cheyenne’ into ‘Chinese Spring’ (with the exception of 2B) indicated that the genes responsible for the frost resistance of ‘Cheyenne’ are localised in chromosomes 5A, 7A, 4B, 5B, 4D and 5D. The genetic basis of frost resistance and problems of analysis are discussed.
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  • 7
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    Theoretical and applied genetics 59 (1981), S. 313-316 
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; Wheat ; Puccinia graminis ; Stem rust resistance ; Monosomic analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Using monosomic analysis genes governing resistance in one wheat variety, ‘E5883’, against stem rust races 15C and 122, were located on specific chromosomes. Against race 15C, a major dominant gene, Sr6, was located on chromosome 2D of ‘E5883’ with minor modifiers found on chromosomes 4A and 6D. Against race 122, the presence of a recessive hemizygous ineffective gene, Sr8, was identified, located on chromosome 6A of variety ‘E5883’.
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  • 8
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    Theoretical and applied genetics 59 (1981), S. 317-325 
    ISSN: 1432-2242
    Keywords: Environmental evaluation ; Plant breeding ; Multivariate analysis ; Wheat ; Climatic variable
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A previous attempt to relate long term yields from the Western Australian wheat belt to climatic factors proved only partially successful. Here, principal component analysis has been used to examine the patterns of variability created by those socio-economic factors which may have obscured any underlying relationship which existed between yield and climate. In fact, these analyses revealed the existence of variation peculiar to particular groups of years, a result which could explain why many attempts to relate crop yields directly to climatic factors have proved unsuccessful. The plant breeding implications of these genotype x environment interactions are considered.
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  • 9
    ISSN: 1432-2242
    Keywords: Wheat ; Endosperm ; Proteins ; Electro phoresis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The major endosperm proteins in a range of genotypes of hexaploid wheat have been fractionated by two-dimensional electrophoresis. The genotypes included nine varieties and forty four intervarietal substitution lines in which chromosomes 1A, 1B, 1D, 6A, 6B or 6D from eight of the varieties have been introduced one at a time into a common genetic background. The appearance of different protein subunits was often correlated with a chromosome substitution. This showed that many of the genes for the high molecular weight protein subunits (molecular weight range 55,000 to 140,000 determined by SDS polyacrylamide gel electrophoresis) are specified by chromosomes 1A, 1B and 1D while many of the lower molecular weight subunits (molecular weight range 30,000 to 45,000) are specified by chromosomes 6A, 6B and 6D. The different protein subunits correlated with chromosome substitution could not always be recognised in the varietal source of the substituted chromosome. The different subunits specified by homologous chromosomes in different wheat varieties may differ in isoelectric point and/or molecular weight.
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  • 10
    ISSN: 1432-2242
    Keywords: Wheat ; Aegilops ventricosa ; Addition lines ; Biochemical markers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The distribution of three biochemical markers, U-1, CM-4 and Aphv-a, -b, among wheat-Aegilops addition lines carrying Mv chromosomes from Aegilops ventricosa (genomes DvMv) has been investigated. Addition lines which had been previously grouped together on the basis of common non-biochemical characters carried marker U-1, a protein component from the 2M urea extract. The added chromosome, in the appropriate genetic background, seems to confer a high level of resistance to the eyespot disease, caused by the fungus Cercosporella herpotrichoides. The other two markers were concomitantly associated with another similarly formed group of addition lines. Both CM-4, a protein component from the chloroform:methanol extract, and Aphv-a, -b, alkaline phosphate isozymes, have been previously shown to be associated with homoeologous chromosome group 4, which suggests that the added chromosome in the second group of addition lines is 4Mv.
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  • 11
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    Theoretical and applied genetics 60 (1981), S. 81-84 
    ISSN: 1432-2242
    Keywords: Wheat ; ‘Norin 10’ dwarfing genes ; Photosynthesis ; Respiration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A comparative analysis of eight cultivars of spring wheat (Triticum aestivum) classified by height as tall (T), semi-dwarf (D1), dwarf (D2) and very dwarf (D3) was conducted to study their efficiency of oxygen exchange during photosynthesis and dark respiration. Two cultivars were included in each height group. Cultivars carrying ‘Norin 10’ dwarfing genes (D1, D2 and D3) were found to have a significantly higher photosynthetic rate per unit leaf area than talls (T) that lack these genes. Among the ‘Norin’ gene carriers, dwarf group (D2) was most efficient, followed by very dwarf (D3) and semi-dwarf (D1). Photosynthetic rate and respiratory rate were found to have a positive relationship.
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  • 12
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    Theoretical and applied genetics 59 (1981), S. 33-37 
    ISSN: 1432-2242
    Keywords: Wheat ; Rye ; Gene transfer ; Translocations ; Homoeologous genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary By producing chromosome substitutions with ‘Imperial rye’ chromosomes 4R (C) and 7R (D) in the wheat cultivar ‘Chinese Spring’ two spontaneous translocation lines were obtained. One involves segments of wheat chromosome 4A and rye chromosome 7R, the other involves portions of wheat chromosome 7B and rye chromosome 4R
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  • 13
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    Theoretical and applied genetics 59 (1981), S. 25-31 
    ISSN: 1432-2242
    Keywords: Seed proteins ; Wheat ; Barley ; Rye ; Ae. umbellulata ; Ag. elongatum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The seed proteins of ‘Chinese Spring’ wheat stocks which possess single chromosomes from other plant species related to wheat have been separated by gel electrophoresis in the presence of sodium dodecyl sulphate. Marker protein bands have been detected for both arms of barley chromosome 5, chromosome E (= 1R) and B (= 2R) of rye, chromosomes A,B (= 1Cu) and C (= 5Cu) of Aegilops umbellulata and chromosomes I and III of Agropyron elongatum. These studies, and previous findings, indicate that chromosome 5 of barley, chromosome 1R of rye, chromosome I of Ag. elongatum and possibly chromosome 1Cu of Ae. umbellulata are similar to chromosomes 1A, 1B and 1D in hexaploid wheat in that they carry genes controlling prolamins on their short arms and genes controlling high-molecular-weight (apparent molecular weight greater than 86,000) seed protein species on their long arms. These findings support the idea that all these chromosomes are derived from a common ancestral chromosome and that they have maintained their integrity since their derivation from that ancestral chromosome.
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  • 14
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    Theoretical and applied genetics 60 (1981), S. 85-88 
    ISSN: 1432-2242
    Keywords: Wheat ; Leaf rust ; Resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The hypothetical leaf rust progress curves of 15 genotypes of wheat were generated by integrating the components of slow rusting resistance determined in the glasshouse. The area under the disease progress curve (AUDPC) from the hypothetical and observed leaf rust progress curves were compared. It was found that the hypothetical AUDPC values of all the genotypes studied were smaller than their respective observed AUDPC values. Possible causes for the discrepancies in the observed and hypothetical values are discussed.
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  • 15
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    Theoretical and applied genetics 60 (1981), S. 161-166 
    ISSN: 1432-2242
    Keywords: Gene expression ; Resistance ; Local virulence ; Stem rust ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Near isogenic/substitution lines of stem rust resistance genes in different backgrounds of ‘Marquis’, ‘Chinese Spring’ and W 2691 and certain varieties with known genes for stem rust resistance were tested against each of 19 Indian cultures of stem rust races/biotypes (14, 15, 17, 21, 21A-1, 24, 34, 40, 40A, 42, 42B, 117, 117A, 117A-1, 122, 184, 194, 222 and 295). Sr 24 (‘Sear's 3D/Ag’), Sr 24 (TR 380-27 4/3 Ag 14-White seeded recombinant with ‘Agent’ type resistance), Sr 25 (‘Sear's 7D/Ag’), Sr 26 (‘Eagle’), Sr 26 (Knott's 6A/Ag translocation), Sr 27 (WRT 238-5), Combination line (Sr Tt1 + Sr 9b) were observed to be completely effective against all the 19 cultures tested. In addition, a number of lines, such as TAF2d (Sr Agi), Line W(Sr Tt2) and Combination III (Sr Tt1 + Sr 9e), were found to be effective against at least three of the most prevalent races (21, 40A and 117A-1) and a virulent race 122 in Indian natural population. Lines carrying genes other than Sr 2, Sr 9a, Sr 9f (‘Chinese Spring’) and Sr 15 (‘Norka’), and Line E were found to be resistant to one or more cultures of stem rust. The background effect upon the expression of a gene was observed by comparing the range of infection on single gene host lines in either different backgrounds and/or in cultivars with known genes for stem rust resistance against the 12 cultures of stem rust races found in India.
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  • 16
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    Theoretical and applied genetics 60 (1981), S. 157-160 
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; Wheat ; Puccinia graminis ; Stem rust resistance ; Inheritance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Two bread wheat accessions, E5008 and E6160, have been genetically analysed for resistance genes effective against Indian cultures of stem rust races, 15C and 122. The inheritance of resistance to each race has been determined from the F1 and F2 of the crosses (resistant parents with the susceptible variety, ‘Agra Local’) and F2 progenies from the backcross to ‘Agra Local’. Tests have been performed to see if the two varieties carry common genes/s for resistance. The identity of the genes for resistance has been established from relevant crosses with single gene lines carrying known genes for resistance. A single dominant gene effective to race 15C in E5008 has been demonstrated to be Sr9b. Of the two recessive genes, each producing distinct infection types (0; and 1–3) against race 122, one gene has been inferred to be Sr12 and the second to be a hitherto undesignated gene. The resistance of E6160 against race 15C is controlled by two genes, one dominant and one recessive. The dominant gene has been identified as Sr9b. The recessive gene has been inferred to be a new gene. Similarly, a dominant gene effective against race 122 in E6160 has been observed to be different from those so far designated. In addition, the presence of modifier gene/s in the variety, E6160 has been suggested.
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  • 17
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    Theoretical and applied genetics 60 (1981), S. 333-337 
    ISSN: 1432-2242
    Keywords: Wheat ; Seed proteins ; Glutenin protein ; subunits
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The inheritance of the high-molecular-weight (HMW) glutenin protein subunits in hexaploid wheat has been investigated by using sodium dodecyl sulphate-polyacrylamide gel electrophoresis to examine the segregation of these subunits in 496 test-cross seeds. The parents of the f1 hybrid were chosen so that the test-cross seeds segregated for all the HMW glutenin bands. Two glutenin subunits from one parent, believed to be controlled by genes on chromosome 1D, segregated as alternatives to two glutenin subunits from the other parent, a result that supports the assumption that these subunits are controlled by allelic genes at each of two loci that are very closely linked. Similar results were obtained for glutenin subunits believed to be controlled by chromosome IB, which suggests that these subunits are controlled also by allelic genes at each of two loci that are very closely linked. A single glutenin subunit band, believed to be controlled by chromosome 1A, segregated as an alternative to a single glutenin band from the other parent, except that one seed did not possess either band. It was concluded that these bands are controlled either by allelic genes or by nonallelic genes that are very closely linked.
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  • 18
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    Chromatographia 14 (1981), S. 19-22 
    ISSN: 1612-1112
    Keywords: Teflon columns ; Chemically modified teflon ; Gas chromatography ; Capillary columns
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Wall-coated open tubular columns prepared from chemically modified teflon tubing have been developed for gas chromatography. Chemical reaction of the inner walls of teflon tubing allows bonding of an adhesive layer on which a variety of stationary phaes can be coated. Test mixtures of alkanes and alcohols were used to investigate the chromatographic properties of these columns and the stability and mixing of the adhesive and stationary phae layers. the results in dicate that mixing of the layers is negligible and that the column is stable for a long period of time.
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  • 19
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    Chromatographia 14 (1981), S. 55-66 
    ISSN: 1612-1112
    Keywords: Capillary columns, glass ; Gas chromatography ; Column preparation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Kapillar-Gas-Chromatographie ist heute das sich am stärksten entwickelnde Gebiet der Gas-Chromatographie. Es gibt viele komplexe, neue Fragestellungen in der Analytik, welche den Einsatz spezieller Kapillarsäulen erfordem. Glücklicherweise gibt es aber auch eine große Zahl von Herstellungsverfahren für Kapillarsäulen, welche — noch mehr als bei der Herstellung von gepackten Säulen — eine Anpassung an die gestellten Aufgaben ermöglichen. In diesem Artikel werden die Herstellungsverfahren für Kapillarsäulen zusammengestellt und Anregungen gegeben, wie aufgaben-orientierte Säulen erreicht werden.
    Notes: Summary Glass capillary column chromatography is the most rapidly growing part of gas chromatography. There are many complex new analytical tasks and they require special capillary columns, Fortunately there is a wide range of column preparation methods available, and they make the preparation of glass capillary columns a more varied job than that of packed columns. In this paper these methods are reviewed and suggestions are given for making task-oriented columns.
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  • 20
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Urea herbicides ; Catalytic hydrolysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A method is described for the rapid catalytic hydrolysis of phenylurea herbicides on silica gel at elevated temperatures. After derivatisation of the anilines produced with heptafluorobutyric acid anhydride final analysis is done on a gas chromatograph equipped with an electroncapture detector. Detection limits are in the 1–5 picogram range. The method has successfully been applied to residue analysis of water samples at the 1 ppb level. The determination of free anilines present in water samples and the potential of various techniques to be used to discriminate between free anilines and parent herbicides are also discussed.
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  • 21
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Graphitised carbon black ; Phenols ; Water pllutants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The fractionation of eleven phenols which may be contaminants in drinking water has been accomplished by using acid-washed graphitised carbon black modified with trimesic acid and PEG 20 M.
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  • 22
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    Chromatographia 14 (1981), S. 447-451 
    ISSN: 1612-1112
    Keywords: Headspace analysis ; Gas chromatography ; Residual analysis of polyethylene terephthalate ; Acetylene reduction assay ; Ethylene evolution in germinating seed ; Acetaldehyde generation in polyester resin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary New application areas for headspace gas chromatography in agricultural and polymer degradation research are described. Specific examples are drawn from the various forms of headspace analysis with emphasis on the automated static equilibrium method.
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  • 23
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    Plant and soil 59 (1981), S. 119-125 
    ISSN: 1573-5036
    Keywords: Intracoleoptile internode ; Water uptake ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Measurements of xylem vessel number and radii in the seminal roots and intra-coleoptile internode (I.C.I.) of five wheat genotypes showed that the conducting capacity of the I.C.I. was close to the main seminal axis, and would restrict flow when the usual 3–5 seminal axes contributed to uptake. The length and hence resistance of the I.C.I. increased with sowing depth, whilst xylem diameter also fell in two genotypes, which would further restrict flow. The resistance per unit length of I.C.I., assuming Poiseuille flow, was 4×10−4 cm−4 day MPa. A pressure drop of 0.15 MPa along an I.C.I. 5 cm long would be required to maintain transpiration under typical field conditions in southern Australia in spring. In a second study of eleven wheat varieties sown up to 10 cm deep, maximum I.C.I. length ranged from 3.6–6.8 cm amongst varieties with similar maximum coleoptile lengths (6–8 cm). Thus considerable variation in hydraulic resistance may be achieved by the appropriate combination of genotype and planting depth. It was concluded that potentially useful differences in the rate of subsoil water use could result.
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  • 24
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    Plant and soil 59 (1981), S. 201-206 
    ISSN: 1573-5036
    Keywords: Acetylene reduction ; Coffee plantation ; Inga jinicuil ; Nitrogen fixation ; Nodule biomass ; Woody legume
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Nodule biomass and yearly C2H2 reduction rates are reported forInga jinicuil, a leguminous tree used for shade in Mexican coffee plantations. Annual fixation by this species approximates 35 kg ha−1; which, when compared to nitrogen additions from fertilizers, represents an important nitrogen input to the coffee ecosystem.
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  • 25
    ISSN: 1573-5036
    Keywords: Azotobacter vinelandii ; Gnotobiotic cultures ; Nitrogen fixation ; Oryza sativa Rhodopseudomonas capsulata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary An all glass tight growth chamber, entirely sterilizable, has been constructed to carry out axenic and gnotobiotic cultures of rice plants (Oryza sativa L.). When grown in liquid medium and in the absence of combined nitrogen but in the presence of the diazotrophsAzotobacter vinelandii andRhodopseudomonas capsulata, rice plants exhibited a complete biological cycle from germination up to ear stage, during a period of time similar to the one encountered in french paddy soil of Camargue. In one experiment, mannitol was given to rice culture medium together withAzotobacter vinelandii andRhodopseudomonas capsulata. In another experiment, mannitol was not given together with Rhodopseudomonas, and still positive nitrogen gain was obtained, although it was less than culture with mannitol. When15N labeled cells of Rhodopseudomonas were added in rice culture medium,15N was partly transferred to rice plant. Among the nitrogen substances excreted from the bacteria in the rhizosphere medium, large organic molecules were shown to be the most abundant in our experimental conditions. Moreover, the concentration of free ammonia or aminoacids present in the rice rhizosphere were always compatible with a bacterial nitrogenase activity.
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  • 26
    ISSN: 1573-5036
    Keywords: Acridine orange ; Barley ; Cerelas ; Microdochium bolleyi ; Nuclear staining ; Phialophora radicicola ; Rhizosphere ; Root cortex death ; Take-all ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Nuclear staining with acridine orange was used to assess cell viability in the cortex of wheat and barley seminal roots from glasshouse and field experiments. Results from this method correlated well with nuclear assessments made in unstained or Feulgen-stained roots, and other evidence is presented to support the validity of the method. The pattern of root cortex death (RCD) was similar in wheat and barley and consistent over a wide range of conditions. Behind the extending root tip and zone of nucleate root hairs, nuclei disappeared progressively from the outer five (of six) cortical cell layers of the root axes, starting in the epidermis. Stainable nuclei remained in the sixth cell layer, next to the endodermis, and in most cell layers around the bases of root laterals and in a small region immediately below the grain. The onset of cell death was apparently related more to the age of a root region than to its distance behind the root tip, and it was not closely correlated with endodermal or stelar development assessed by staining with phloroglucinol/HCl. The rate of RCD was much faster in wheat than barley in both glasshouse and field conditions, and faster in some spring wheat cultivars than in others in the glasshouse. RCD occurred in sterile vermiculite and perlite and was not enhanced by the presence of soil microorganisms; nor was it enhanced in soil by the addition of the non-pathogenic fungal parasitesPhialophora radicicola var..graminicola orMicrodochium bolleyi. RCD is suggested to be endogenously controlled by the amount of photosynthate reaching the cortex. Its implications for growth of soil microorganisms and especially for growth and biological control of root-infecting fungi are discussed.
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  • 27
    ISSN: 1573-5036
    Keywords: Bacteroids ; Cowpea ; Nitrogen fixation ; Peanut ; Rhizobium ; Siratro
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Acetylene reduction activity and nitrogen accumulation in the plant top per unit nodule mass were compared among peanut, cowpea and siratro plants nodulated by six different strains of Rhizobium. Peanut was found to have several fold higher values than cowpea and siratro for both parameters for all strains of Rhizobium which nodulated it effectively, but the bacteroid content of the peanut nodules was similar to those of cowpea and siratro.
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  • 28
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    Plant and soil 62 (1981), S. 279-290 
    ISSN: 1573-5036
    Keywords: Amino acids ; Ammonium ; Copper ; Barley ; Nitrate ; Nitrogen ; Wheat
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effects of different nitrogen sources (NH4, NO3, and NH4 NO3) on the uptake of copper by wheat and barley growing in solution culture were compared in three experiments. Both the copper concentration and weight gain of shoots and roots were found to decrease in the order NO3〉NH4 NO3〉NH4 irrespective of the solution copper concentration. Ammonium nitrogen was also found to decrease the copper concentration of wheat grown on a copper deficient soil compared with a nitrate source of nitrogen. Increasing concentrations of ammonium ions in solution culture caused ammonium toxicity and reduced both plant copper concentrations and vegetative yield. Biochemical investigations using paper chromatography revealed that the amino acid asparagine was the major detoxification product of ammonia in wheat. Copper deficient plants were found to have elevated levels of amino acids compared with controls, irrespective of the nitrogen source.
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  • 29
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    Plant and soil 62 (1981), S. 331-336 
    ISSN: 1573-5036
    Keywords: Legumes ; Nitrogen fixation ; 15N
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The combination of using15N for determining the amount of nitrogen fixed by a legume crop in field experiments and the labelling of only one treatment at a time in each treatment combination is shown to be conceptually and experimentally valid for determining the effect of cultural practices on the amount of nitrogen fixed by a legume crop.
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  • 30
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    Plant and soil 63 (1981), S. 283-289 
    ISSN: 1573-5036
    Keywords: Afzelia quanzensis ; Brachystegia spiciformis ; Ectomycorrhiza ; Miombo woodland ; Nitrogen fixation
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Ectomycorrhizae were found in root samples of the treesAfzelia quanzensis Welw. andBrachystegia spiciformis Benth. (Caesalpiniaceae), collected in the coastal miombo type woodland 50 km west of Dar-es-Salaam, Tanzania. Root nodules with a structure resembling that of nitrogen-fixing root nodules of other leguminous plants were observed in theA. quanzensis material. The climate of the locality is rather dry, and strongly seasonal. In the tropics, ectomycorrhizae have previously been found only in humid or rain forest climate zones.
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  • 31
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    Photosynthesis research 1 (1981), S. 243-249 
    ISSN: 1573-5079
    Keywords: C4 grass ; C3 legume ; light utilization efficiency ; temperature
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    Topics: Biology
    Notes: Abstract The effect of temperatures between 15 and 50°C on the light utilization efficiency of leaf net photosynthesis was studied in two C4 grasses and two C3 legumes. In the legumes, light utilization efficiency (μ mol of CO2 fixed per μ Einstein of incident photosynthetic quantum flux) declined linearly with temperature between 15 and 45°C. On the other hand, it was independent of temperature between 15 and 40°C in the grasses, but it declined rapidly between 40 and 50°C. Values for grasses were greater than those for legumes at all temperatures; for example, at 30°C the ratio of the mean values of grass to legume was 1.6–1.7 which is similar to a previously published value of 1.6. Light utilization efficiency was similar for grasses and legumes only at temperatures below 10 and above 50°C. These findings are compared with published data, especially those of Ehleringer and Björkman, and their implications for predicting or interpreting the distribution of C3 and C4 species are briefly discussed.
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  • 32
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    Euphytica 30 (1981), S. 467-481 
    ISSN: 1573-5060
    Keywords: Wheat ; Australia ; Mexico ; morphology ; physiology ; numerical classification ; ordination ; time trend
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Plants of 43 Australian wheat cultivars of historical and contemporary importance and 7 Mexican introductions were grown in a glasshouse and measured for 27 morphological and physiological attributes. Phenotypic relationships among the cultivars across all attributes were examined by hierarchical classification and ordination procedures. Seven major groups of cultivars delimited in the classification were broadly related to extremes of plant type (3 tall, late-flowering Australian wheats and 2 early-flowering Mexican wheats of high harvest index were contrasting extremes), region of breeding origins (southern/western versus northern Australian cereal regions) and pedigree (strong influences of the Norin 10 x Brevor cross in some Mexican cultivars and Mexican derivatives; of Federation and Early Gluyas in the pedigrees of southern/western wheats; and of Gabo in the northern wheats). Some attributes of the Australian cultivars were correlated with the year of release suggesting the progressive development of cultivars that are shorter. earlier to ear emergence and with a high harvest index.
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  • 33
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    Euphytica 30 (1981), S. 247-252 
    ISSN: 1573-5060
    Keywords: Wheat ; Triticum boeoticum ; wild einkorn ; Triticum monococcum ; einkorn ; water stress ; leaf water potential ; photosynthesis ; domestication ; adaptation
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A comparative study of photosynthetic response to water stress was conducted with one genotype of wild einkorn (Triticum boeoticum, W) and one of domesticated einkorn (T. monococcum, C). Per unit leaf area, W showed a better performance for photosynthetic and transpiration activities, even under dry air and dry soil conditions. Its leaf water potential was always higher than that of C at any level of soil water potential. The difference in photosynthetic recovery from severe drought between W and C was also obvious. The photosynthetic rate, transpiration rate and water status of the leaves observed at 20 h after rewatering was almost the same as non-stressed leaves in W, whereas in C the photosynthetic rate was about half that of the non-stressed leaves, which was accompanied with a low transpiration rate and a high gas diffusion resistance. The ability of W to maintain a proper water balance over a wide range of soil water potential and to recover rapidly from severe drought seems to be a result of adaptation to its hard habitats. However, under favourable water supply, the photosynthetic rate per unit leaf nitrogen was higher in C than in W. This may be advantageous to bring about a better plant growth than W on the arable land where the improved water supply is guaranteed.
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  • 34
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    Hydrobiologia 80 (1981), S. 225-230 
    ISSN: 1573-5117
    Keywords: aquatic ; temperature ; soil ; composition ; gas ; water ; annual change
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    Topics: Biology
    Notes: Abstract Heat penetration and thermal lag in the submersed soil surrounding the roots of aquatic plants depends on two fundamental thermal properties of the substrate, volumetric heat capacity (CV) and thermal conductivity (k). The relationship of these parameters to the fractions of organic and mineral matter, gas and water in natural and simulated aquatic soils was investigated. The gas fraction was found to be insignificant and it was possible to make good estimates of CV and k from a knowledge of substrate water content alone.
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  • 35
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    Hydrobiologia 83 (1981), S. 419-423 
    ISSN: 1573-5117
    Keywords: Anabaena spiroides Klebahn var.crassa Lemm. ; filament length ; temperature
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    Topics: Biology
    Notes: Abstract Temperature dependence of filament length ofAnabaena spiroides Klebahn var.crassa Lemm. was examined for a strain isolated from Lake Kasumigaura, Japan. The length of the algal filaments is shown to have good correspondence with the thermal master reaction of cell multiplication.
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  • 36
    ISSN: 1573-5117
    Keywords: Thermal tolerance ; temperature ; benthic insects ; Trichoptera ; Ephemeroptera
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    Topics: Biology
    Notes: Abstract The acute thermal tolerances of four southeastern stream insect species, Ephemerella invaria (Walker), Stenonema ithaca (Clemens and Leonard), Symphitopsyche morosa (Hagun), and Brachycentrus lateralis (Say) were determined using an artificial stream enclosure. All species were acclimated at 10°C for 72 hours prior to instantaneous immersion into heated water for 96 hours. Percent mortality was recorded and the temperature at which 50% mortality occurred determined (LT5o). Data were subjected to standard statistical analysis. Thermal tolerance values were compared between species tested and to results from previous investigations using similar methodologies. The evolution and life histories of these species were also discussed in relation to their thermal tolerance values.
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  • 37
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    Hydrobiologia 83 (1981), S. 245-254 
    ISSN: 1573-5117
    Keywords: active metabolism ; basal metabolism ; metabolic compensation ; swimming performance ; temperature
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    Topics: Biology
    Notes: Abstract Oxygen consumption was measured for three tropical fishes,Exodon paradoxus, Leporinus fasciatus andLabeo erythrurus in relation to swimming speed and temperature. For each species the logarithm of oxygen consumption (mg 02 · g−1 · h−1) increased linearly with relative swimming speed (1 · s−1) with the value of the regression coefficients varying inversely with temperature. Active metabolism and critical swimming speed ofE. paradoxus andL. fasciatus increased with temperature to a maximum at 30 and 35° C respectively. Basal metabolic rates ofE. paradoxus andL. fasciatus increased with temperature. Metabolic rates and critical swimming speed of the three fishes studied were consistent with values for polar, temperate and other tropical species over their respective thermal ranges of tolerance. Tropical fishes have lowered their metabolism and swimming performance from that expected for many temperate species at the same temperature.
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  • 38
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    Hydrobiologia 83 (1981), S. 255-256 
    ISSN: 1573-5117
    Keywords: thermoregulation ; behavior ; temperature ; triggerfish ; Balistes fuscus ; tropical reef ; Ichthyotron
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    Topics: Biology
    Notes: Abstract Ten blue triggerfish,Balistes fuscus, were tested individually for 3 days each in Ichthyotron electronic shuttleboxes to measure their thermoregulatory behavior. The modal thermal preferendum, a species-specific measure of temperature preference which is independent of prior thermal acclimation, was 25 °C. The triggerfish voluntarily occupied a 16–27 °C range of temperature, out of a potentially available range of 0–50 °C. There was no significant difference in preferred temperature between night and day, indicating lack of a thermoregulatory rhythm in this species. The preferred temperature range of this tropical marine reef species is similar to that of cool temperate freshwater and marine fishes; many warm temperate species prefer higher temperatures.
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  • 39
    ISSN: 1573-5060
    Keywords: Wheat ; Triticum aestivum ; wheat breeding ; selection ; grain yield ; harvest index
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The relationships between the F2, F3, F4 and F5 generations for grain yield were determined using random, pedigreed lines derived from each generation. The lines from two crosses were grown in plots at two sites over two years. In the first year, only F2 and F3 derived lines were available, but in the second year the F2 to F5 were grown. Correlations between lines in one generation and the mean of lines derived from them in a following generation increased as the generations were advanced. Correlations between consecutive generations were higher than those between generations two or three apart. Correlations between F2 and F5 derived lines, which indicate the effectiveness of selecting F2 lines, varied from 0.10 ns to o.49** when lines from both generations were grown in the same environment. Correlations between years of lines from the same or different generations were low and often non-significant. Harvest index was measured on the F2 and F3 derived lines at the one site in the first year. Selection for improvement of grain yield using harvest index was no more effective than selection for yield directly, when considered across years. It is conclued that, while gains in yield can be achieved by selecting for yield in early generations, a foremost consideration needs to be the influence of different sites and years on the effectiveness of selection.
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  • 40
    ISSN: 1573-5036
    Keywords: Alfalfa ; Correlation coefficient ; Factor analysis ; Leaf area ratio ; Nitrogen fixation ; Net assimilation rate ; Path-coefficient analysis ; Relative growth rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Twelve alfalfa cultivars inoculated with an indigenous strain (RM9) ofRhizobium meliloti, were compared for their seedling morphological characters, and growth characters, including net assimilation rate (NAR), relative growth rate (RGR), leaf area ratio (LAR) and relative nitrogen assimilation rate (RN). Highly significant differences were obtained between cultivars for most characters. Simple correlation showed that NAR influenced RGR (r=0.91) more than leaf area ratio (LAR) (r=−0.44), and that most characters measured were highly correlated with seedling dry weight. Factor analysis showed that NAR, RGR and RN contributed 25% of the total variation in the dependence structure. The grouping indicated that the higher the NAR and RN the greater was the RGR. Path-coefficient analysis showed that NAR had more important direct and indirect effects than RN in dry matter accumulation. The relationship implied that selection for plants with high NAR, or high efficiency in converting light energy to dry matter production could contribute greater N2 fixation in alfalfa.
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  • 41
    ISSN: 1573-5036
    Keywords: Amino acids ; Proteins ; Wheat ; Salinity ; Soil types
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effects of four lysimeter soil series under three salinity levels were evaluated for grain yield, wt/1000 seeds, protein, and amino acids in Mexican dwarf wheat (Triticum aestivum L. var. Cajeme 71). The soil series consisted of: Holtville clay loam, Greenfield sandy loam, San Emigdio sandy loam, and Altamont clay loam. The irrigation water salinity levels were designated: low −2.2 mmho, medium −4.2 mmho, and high −7.1 mmho. No significant differences were found in the amount of grain harvested or wt/1000 seeds in the 1976 crop produced on the differential soil series. The yield of the 1977 crop was significantly affected by the soil types. Effects of soil type on the protein amino acids in the grain in both years were similar. Significantly higher protein amino acid levels of histidine, arginine, aspartic acid, threonine, serine, glutamic acid, glycine, alanine, cystine, valine, methionine, isoleucine, leucine, tyrosine, and phenylalanine were found in the grain grown on Altamont clay loam soil than the other types. The free amino acids in grain from the 1976 and 1977 crops were similarly affected by the soil types, except that the quantitative values of the free amino acids were substantially lower in 1977 than in 1976. The free amino acids significantly influenced by soil types were tryptophane, lysine, arginine, aspartic acid, threonine, serine, glycine, alanine, valine, isoleucine, tyrosine, and phenylalanine. In both years' crops, the sum of the free amino acid fractions was significantly higher in the grain produced on the Altamont soil than on the other soils. Salinity level in the irrigation water did not affect the 1976 crop yield or wt/1000 seeds. Although yields of the 1977 crop were significantly reduced by salinity, the wt/1000 seeds was not. The sum of protein amino acids was significantly higher in the 1976 and 1977 grain crops irrigated with high salinity water than in low salinity irrigated crops. An increased salinity irrigation water significantly reduced the sum of free amino acid fractions in the 1976 grain crop. Since some of the free amino acids in the 1977 grain crop increased while the others decreased due to the salinity level in the irrigation water, the sum of the free amino acid fractions was not significantly influenced. Significant interactions were found between soil types and salinity levels on free arginine, threonine, serine, glutamic acid, and alanine, and also on the sum of the free amino acids in the 1976 wheat grain. In the 1977 wheat grain, there were significant interactions between soil types and salinity levels on the free glutamic acid, valine, leucine, tyrosine, and phenylalanine, and on protein serine, glutamic acid, glycine, alanine, and the sum of the protein amino acids. The amounts of essential amino acids expressed as mg of amino acid/g of protein were not affected by the soil types or salinity levels. With the exception of lysine, and possibly threonine and methionine plus cystine, the essential amino acids were present in the grain at concentrations equal to or greater than recommended by WHO and FAO.
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  • 42
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    Plant and soil 59 (1981), S. 473-477 
    ISSN: 1573-5036
    Keywords: Hexachloroxyclohexane ; Nitrogenase activity ; Nitrogen fixation ; Redox potential ; Rhizosphere ; Rice plant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The influence of application of hexachlorocyclohexane (HCH=gamma BHC), to a submerged tropical field soil at rates equivalent to recommended field rates (1–2.5kg a.i./ha) and twice this level, upon the rhizosphere soil nitrogenase, nitrogen fixers, and soil redox potential (Eh) was investigated. The rhizosphere soil from HCH-treated field exhibited significantly higher nitrogenase activity than that from untreated fields. HCH retarded the drop in redox potential of the field soil upto 80 days after transplantation under submerged conditions. Populations of nitrogen-fixingAzospirillum sp. and Azotobacter, to a greater extent, and anaerobic organisms, to a lesser extent, were stimulated in HCH-treated soils. Results indicate the stimulation of heterotrophic nitrogen-fixing bacteria by HCH in submerged paddy soils.
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  • 43
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    Plant and soil 60 (1981), S. 139-142 
    ISSN: 1573-5036
    Keywords: Legumes ; Nitrogen fixation ; Nodulation ; Winged beans
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Only legumes of the cowpea cross-inoculation group, including the winged bean (Psophocarpus tetragonolobus) were found to form nodules in a temperate zone soil with no previous history of legume cropping. Isolates from root nodules from uninoculated winged beans grown in the field only nodulated legumes in the cowpea cross-inoculation group.Rhizobium japonicum formed ineffective nodules with the winged bean.
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  • 44
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    Plant and soil 60 (1981), S. 309-315 
    ISSN: 1573-5036
    Keywords: Acetylene reduction ; Aeschynomene americana ; Flooding ; Leaf water potential ; Nitrogen fixation ; Soil moisture deficits
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Studies on the tolerance ofAeschynomene americana L. to periods of flooding or soil moisture deficit were conducted in an attempt to elucidate nitrogen fixation as affected by soil moisture. Nitrogenase activity was not reduced significantly in pot-grown Aeschynomene plants subjected to flooding in greenhouse conditions. After 20 days of withholding water from the soil, nitrogenase activities of the drought-stressed plants were much lower than those of either the well-watered or flooded plants. Leaf water potentials were similar in flooded and control plants; however, the droughted plants had leaf water potentials that were 4 bars lower than those of the control plants. Aeschynomene plants were tolerant to long-term periods of flooding, but exhibited a reduction in nitrogenase activity and leaf water status when subjected to soil moisture deficits.
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  • 45
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    Plant and soil 61 (1981), S. 93-111 
    ISSN: 1573-5036
    Keywords: Ineffective nodules ; Medicago laciniata ; Nitrogen fixation ; Nodulation ; Root temperature
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Medicago laciniata, an annual leguminous plant of Saharo-Sindian origin, is particularly refractory to root nodulation by most strains ofRhizobium meliloti. Using a series of such bacterial strains belonging to the 8 groups of Brockwell and Hely, and a variety of environmental conditions, it was noted that several normally non-nodulating strains (at 20°C) produced ineffective nodules at root temperatures of 24°C to 28°C. Nodulation at 20°C failed to occur in the presence of a wide variety of test compounds and physical conditions. No phytoalexins or anti-Rhizobium growth inhibitors were isolated from inoculated root tissue at any temperature. Temperature shift experiments indicated no infection of the root hairs at 20°C, and infection threads produced at the permissive root temperature failed to elongate after transfer to 20°C. However, if meristematic activity had been initiated in the inner root-cortical cells as a result of infection thread penetration at 28°C, no blockage of nodule maturation occurred upon subsequent transfer to 20°C root temperature. Nodules produced at 28°C were completely devoid of nitrogenase activity, although the apical (but not the distal) regions contained normal-appearing bacteriods, surrounded by enclosing membranes, and possessed a fully functional leghaemoglobin. A shortage of metabolic energy did not appear to be involved in the ineffective response. A hypothesis to explain the nodulation phenomenon observed was based on the observation in the roots of 2 factors present at 20°C but not at 28°C.
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  • 46
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    Plant and soil 61 (1981), S. 135-143 
    ISSN: 1573-5036
    Keywords: Hydrogen ; Nitrogen fixation ; Nodulated roots ; Pea ; Respiration ; Soya bean
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Oxygen uptake, carbon dioxide evolution and nitrogenase activity, measured either as hydrogen evolution (under argon 80%, oxygen 20%) or as the reduction of acetylene to ethylene, were assayed over the same time period by a direct mass-spectrometric method. When carbon dioxide evolution was used to estimate carbohydrate consumption, the results agreed with other work on whole plants. The RQ values obtained in these experiments were always less than 1.0 and thus the carbohydrate consumption calculated from oxygen uptake suggests that previous estimates, using carbon dioxide evolution as a measure of the cost of nitrogen fixation may be underestimates. Lag periods observed in the reduction of acetylene to ethylene suggest that there is a resistance to diffusion of gases in the root nodules.
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  • 47
    ISSN: 1573-5036
    Keywords: Biofuel ; Leguminous trees ; Nitrogen fixation ; Semi-arid
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Sand culture pot experiments were carried out with Proposis seedlings in the greenhouse on a nitrogen free nutrient solution with increasing levels of sodium chloride. All species tolerated a 6,000 mg/l salinity with no reduction in growth.P. velutina was the only species that poorly tolerated the 12,000 mg/l salinity level.P. articulata, P. pallida, andP. tamarugo tolerated 18,000 mg/l NaCl with little reduction in growth and grew slightly in a salinity (36,000 mg/l NaCl) greater than seawater. This is the first legume known to grown in salinities equivalent to seawater.
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  • 48
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    Plant and soil 61 (1981), S. 53-63 
    ISSN: 1573-5036
    Keywords: Acetylene reduction ; Inoculation ; Klebsiella oxytoca ; Nitrogen fixation ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Of 45 fermentative gram negative bacterial isolates examined from wheat roots, three were capable of fixing atmospheric nitrogen as determined by the acetylene reduction technique and by protein contents of cells. A gram negative non-motile facultatively anaerobic bacterial strain capable of N2 fixation was identified asKlebsiella oxytoca ZMK-2. Optimal growth and N2 fixation occurred at pH 6.5. The optimum temperatures for growth under anaerobic conditions ranged between 30°–37°C. Acetylene reduction by intact cells was strikingly inhibited by 0.1 atm. or greater partial pressure of O2. Furthermore, the accumulation of H2 in the gas phase over cultures ofKlebsiella oxytoca ZMK-2 at partial pressures greater than 0.02 atm. resulted in a striking inhibition in the rate of C2H2 reduction. The addition of suspensions of eitherKlebsiella oxytoca ZMK-2 orAzotobacter vinelandii or a mixed culture of these two organisms to axenic cultures of wheat plants produced no significant increase in plant growth as measured by plant dry weight or nitrogen content of plants.
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  • 49
    ISSN: 1573-5036
    Keywords: Azospirillum brasilense ; Cereals ; Nitrogen fixation
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The potential of the nitrogen fixing bacteriumAzospirillum brasilense to enhance development and increase growth of several gramineae was investigated. In both sterilized and non-sterilized systems heading and flowering occurred earlier in the inoculated plants as compared to the noninoculated ones. Total shoot and root weights, total-N content, plant height and leaf length were significantly increased by inoculation.
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  • 50
    ISSN: 1573-5036
    Keywords: Host selection ; Nitrogen fixation ; Nodule structure ; Rhizobium trifolii ; TemperatureTrifolium pratense
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary 1. Nodule structure was examined in the red clover cultivar S123 and in lines (designated H2) separately bred for high yield withRhizobium trifolii strains RCR 0403 and RCR 5. Plants were grown at 16/11, 22/17 and 27/22°C in a 16 h day at 25,000 lux. 2. The larger yields of bred lines compared with S123 were directly correlated with larger aggregate nodule size, larger infected zones and with more bacteroid tissue. Over all treatments the correlation of plant dry weight with aggregate areas of bacteroid tissue, assessed in median longitudinal section, accounted for 79% of the variance. 3. Yields were unrelated to the proportion of uninfected cells and vacuoles within the bacteroid zone. 4. Effects of host type and strain on nodule structure and yield were greatest at the moderate temperature and least and most irregular at high temperature. 5. Bacteriod tissue degenerated more rapidly in S123 than in the bred lines, more rapidly with RCR 0403 than RCR 5 and more rapidly at the high temperature than at moderate or low temperatures. 6. Aggregate nodule size irrespective of treatment was correlated with the aggregate sizes of nodule meristem and differentiating tissues. Nodule comtex comprised a larger proportion of the nodule section at 17 days than subsequently. Other than as specified above, the size relationships of the different tissues of the nodule were unaffected by host selection, temperature, bacterial strain or plant age. 7. At 22/17°C over a 17–25 day period the increment in dry matter per mm2 active nodule tissue was similar for H2 and S123 plants and was less for RCR 0403 (3.33 mg) than for RCR 5 (6.87 mg). At 27/22°C the effeciency of bacteroid tissue was much less,viz. 0.67 and 1.23 mg per mm2 respectively. 8. Nodule tissue areas and volumes were closely related so that unit volumes of active bacteriod tissue in general promoted similar dry matter increment in S123 and bred lines,viz. about 50.5 mg mm−3 at 22/17° for RCR 0403 and 80.8 mg mm−3 for RCR 5. The latter was associated with a fixation rate of 0.157 mg N mm−3 active tissue day−1.
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  • 51
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    Plant and soil 61 (1981), S. 189-202 
    ISSN: 1573-5036
    Keywords: Actinomycete symbiosis ; Alder ; Alnus glutinosa ; Endophyte ; Farmyard manure ; Forestry ; Frankia ; Inoculation ; Nitrogen fixation ; Nodulation ; Root nodules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The occurrence and the infectivity of Frankia, the root-nodule endophyte ofAlnus glutinosa, were studied in different kinds of soil in the Netherlands. Both field and pot experiments indicated that many soils, on which alders have not been grown before, had low numbers of endogenous Frankia or none at all. Inoculation of these soils usually enhanced growth and nodulation of alders. The effect of fertilizer treatments on growth and nodulation ofA. glutinosa were studied in experimental plots. Alders grown in sandy soils, dressed with farmyard manure had the highest yield and the most nodules. The influence of inoculation with homogenates of Sp(+) and Sp(−) nodules and with a pure culture of Frankia AvcIl were studied in pot experiments. The quantity of different kinds of inoculum needed to obtain good growth and nodulation of alder was estimated. The results indicated that addition of a nodule homogenate of 90 g fresh AvcIl Sp(+) nodules is sufficient to inoculate one hectare of nursery soil to produce 10 nodules per plant, while a thousand times larger amount of inoculum is necessary when Sp(−) nodules are used. The limitations and the potentials of using nodule homogenates and pure cultures of Frankia for inoculation in forestry are discussed.
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  • 52
    ISSN: 1573-5117
    Keywords: Asellus ; isopod ; temperature ; water quality ; eggs ; survival ; development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The rate of development and degree of survival of Asellus aquaticus eggs outside the marsupium of ovigerous females are affected by water quality and temperature. Eggs were maintained in polluted river water and relatively clean canal water. Developmental rates increase with increased temperature, but survival decreases. Eggs from polluted site ovigerous females survive better in clean water than in polluted water. Eggs from clean site ovigerous females maintained in polluted water have significantly lower survival rates than eggs from the polluted site at all temperatures tested. The developmental rate of clean site eggs is increased significantly in polluted water at 10–25 °C, possibly as a response to the stress imposed upon them. It is suggested that the method outlined might form the basis of a useful bioassay technique for measuring water quality.
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  • 53
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    Hydrobiologia 76 (1981), S. 33-44 
    ISSN: 1573-5117
    Keywords: Corixidae ; Gammaridae ; temperature ; salinity ; aquatic macrophytes ; food resources ; predation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract When observations began the population of Watch Lane Flash consisted of Gammarus duebeni and Sigara lateralis. Gammarus tigrinus was then introduced; probably during a transfer of water from a nearby canal. G. tigrinus rapidly increased in numbers and at the same time G. duebeni and S. lateralis decreased to zero. There followed a partial recolonisation by corixids but the species present were Sigara concinna and Sigara dorsalis. Throughout the study period corixid populations were stable in two immediately adjacent water bodies, one of which also contained G. duebeni. Thus the changes described were associated with the presence of G. tigrinus. The reasons for the success of G. tigrinus and its effects on other gammarids and corixids are discussed.
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  • 54
    ISSN: 1573-5117
    Keywords: 2,4-D ; bioassay ; season ; TIm ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The paper deals with the variations in the toxicity of 2,4-D to Cyprinus carpio at different temperatures during different seasons of the year. The higher temperature has higher toxicity and vice versa at the same concentration. The TLm values indicate that there is a 7–7.5 fold increase in toxicity with the rise in temperature from 17°C in February (winter) to 39°C in May (summer). These results have significance in manipulating the 2,4-D doses for the eradication of aquatic weeds in different seasons.
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  • 55
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    Chromatographia 14 (1981), S. 576-578 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Tortuosity factor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The relationship between the obstructive factor γ and velocity was restudied. The dependence of the obstructive factor on velocity was verified. The effects of diffusion coefficient and particle-to-column diameter ratio on the obstructive factor-velocity relationship were investigated. The results are consistent with Hawkes' hypothesis that values of γ at low velocities are averages over tightly packed and loosely packed domains while at high velocities they are weighted in favour of the loosely packed domains where there is more flow.
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  • 56
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    Chromatographia 14 (1981), S. 648-652 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Gas-liquid adsorption ; Bulk solution ; Mixed stationary phases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary It is shown that the blending of some retention effects can make the resolution of complex mixtures on short classical columns as effective as on capillary columns.
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  • 57
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    Chromatographia 14 (1981), S. 699-703 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Headspace analysis ; Aromatic hydrocarbons ; Water analyses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The possibilities of using headspace analysis of aromatic hydrocarbon traces in aqueous solutions with changing values of the partition coefficients are discussed. A variant of headspace analysis of the simplest aromatic hydrocarbon in natural and waste water is described. It involves two-step gaseous extraction of a sample in vessels of varying volume before and after the equilibrium phase is replaced with a pure gas (air or nitrogen). This method permits to analyse 5–50 ml water samples with benzene and toluene contents varying from the ppb to the ppm range within an error not exceeding 155. The analysis time is about 1.5 h. The presence of non-volatile organic or mineral substances does not influence the determination. This method is unsuitable to heterogeneous systems (aqueous oil emulsions): before carrying out the analysis for the hydrocarbon content these systems have to be homogenized first.
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  • 58
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Open tubular (capillary) columns ; Glass columns ; Fused-silica columns ; Column testing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Column characteristics affecting the chromatographic behavior of glass and siliceous glass (“fused silica”) capillary columns include the dimensional uniformity of the column, the physical and chemical characteristics of the column wall and the characteristics of the liquid phase. In the case of the coated column the uniformity and thickness of the liquid phase film are the most important criteria affecting column reproducibility. The paper discusses these factors and their influence on column performance.
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  • 59
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    Chromatographia 14 (1981), S. 203-211 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Quantitative analysis ; Copper oxide converter ; Inorganic gas analysis ; Determination of fluorine and oxygen ; Hydrocarbon analysis ; Wine analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A review of past activities concerning selected industrial analytical problems is given. This includes the following question: preparation of pure gas mixtures to be used for calibration, catalytic conversion of ester and pyridin samples to carbon dioxide and a one-point calibration method using peak heights, both for quantitative analysis, analysis of gas mixtures containing fluorine and inorganic fluorine compounds and the determination of the oxygen and fluorine content of the sample, separation and identification of hydrocarbons in shale oil and petroleum fraction samples, and analysis of wine.
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  • 60
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    Chromatographia 14 (1981), S. 143-147 
    ISSN: 1612-1112
    Keywords: Capillary columns ; Gas chromatography ; Retention index ; Structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The retention index of twenty different homologous series of esters have been determined experimentally on polar (Carbowax 1540) and non-polar (squalane) columns. General equations to calculate retention index have been established by statistical methods. The influence of the length and inductive effect of acid and alcohol chains and the relative position of the carboxylic group are discussed.
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  • 61
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    Chromatographia 14 (1981), S. 285-288 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Porous layer open tubular columns ; Kaolin as support ; Column performance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary PLOT columns have been prepared with kaolin as the liquid phase support. These columns show good efficiency with different stationary phases and good thermal stability with polar phases. The performance of columns is shown by the separation of various mixtures such as fatty acids, phenols and anilines which are of analytical importance.
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  • 62
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    Chromatographia 14 (1981), S. 39-40 
    ISSN: 1612-1112
    Keywords: Xylidine isomers ; Heteroaromatic liquid phases ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Nicotinic acid and 1H-benzotriazole appreciably resolved all the xylidine (dimethylaniline) isomers, while benzimidazole, nicotinamide and phthalimide can also separate all the isomers except 2,4- and 2,3-xylidines. The analyses were carried out on supports which were not treated with an alkali.
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  • 63
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    Chromatographia 14 (1981), S. 345-350 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Silica capillaries ; Glass capillaries ; Mixed gum phases ; Polarity and selectivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Mixed phases of Superox 20M and OV-1 can be coated homogeneously on the untreated wall of fused silica capillary columns. Excellent columns with regard to efficiency, inertness and thermal stability can be obtained. (CE〉95% and MAOT≥250°). The polarity and selectivity were ascertained with Rohrschneider-Reynolds probes and a capillary polarity test mixture. The analysis of an essential oil mixture illustrates the possibilities of mixed phases in practical capillary GC.
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  • 64
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Capillary columns ; Fused silica ; Contact angle ; Wettability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary This paper describes the systematic characterization of glass and the newly introduced fused silica and quartz capillary columns from surface wettability measurements. Common gas chromatographic stationary phases were used in capillary-rise measurements at temperatures up to 300°C. By construction of Zisman plots and using the Cassie equation, the relative surface concentrations of wettable and non-wettable groups were determined. By application of the Fowkes equation, the dispersion force component of the surface energy was investigated. The influence of various surface treatments such as leaching, silylation, and polymeric film formation are discussed. Wettability measurements were also used to evaluate the thermostability of various treated surfaces and to compare the surface properties of glass, quartz, and fused silica. The wettability of the surfaces with selected stationary phases as a function of temperature is also discussed.
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  • 65
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Polycyclic aromatic hydrocarbons ; Retention index ; Average molecular polarizabilities
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A significant correlation has been found between the retention indices of polycyclic aromatic hydrocarbons on non-polar stationary phases and the average molecular polarizabilities of the molecules separated on these phases. Equations have been derived for the determination of the average molecular polarizabilities, directly from the retention indices.
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  • 66
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    Chromatographia 14 (1981), S. 69-72 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Polynuclear aromatic hydrocarbons ; Retention index ; Vapour pressure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The retention index of a planar polynuclear aromatic hydrocarbon on the GC phases OV-101, SE-52, and OV-17 is strictly related only to the boiling point, and less closely to the relative molecular mass. The very approximates relation with connectivity index ins only a consequence of the latter. On a nematic lqiuid crystal phase, a variation of activity coefficient, expressed in terms of a shape factor, also influences the retention of PAH.
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  • 67
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    Chromatographia 14 (1981), S. 269-276 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Detector performance ; Trace analysis ; Catalytic conversion ; Multidimensional gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Relationships are derived describing how the detection limit of a chromatographic system depends on the minimum detectable limit of the detector and the chromatographic parameters such as column length, efficiency, carrier gas flow rate and the capacity factor. Performance data of detectors developed in the last 25 years at the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences are given and a few selected application examples are listed. These include trace analysis by preconcentration and by direct analysis and the utilization of multidimensional gas chromatography with two columns, two detectors, a 12-port valve, and a catalytic conversion reactor.
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  • 68
    ISSN: 1612-1112
    Keywords: Gas chromatography ; C1−C5 Hydrocarbons ; Dimethyl ether
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An analytical GC method was developed which uses a single packed column consisting of three packings in series prepared with the following liquid phases: dimethyl sulfolane, propylene carbonate, and silver nitrate. This system provides satisfactory resolution of mixtures of C1−C5 hydrocarbons and dimethyl ether obtained when converting methanol to gasoline. Due to the high capacity of the column it is possible to inject larger sample amounts permitting trace analysis.
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  • 69
    ISSN: 1612-1112
    Keywords: Phthalides ; Umbelliferae ; Liquid-solid chromatography ; Gas chromatography ; Ligustilide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A liquid-solid chromatographic pre-fractionation of naturally occurring phthalides has been developed. The LSC was carried out on a column of silica applying a 1–50% gradient elution of diethyl ether (containing 2% methanol) in pentane. The enrichment in the fractions led to better possibilities for a gas chromatographic separation and isolation allowing further studies by spectroscopic methods. Ligustilide may easily isomerize during GC as a result of ageing of the column.
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    Chromatographia 14 (1981), S. 601-602 
    ISSN: 1612-1112
    Keywords: Ethanolamines ; Ethylene glycols ; Direct separation ; Gas chromatography ; Short glass capillaries
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An effective and rapid GC separation of ethanolamines, even in the presence of ethylene glycols, using short glass capillary columns is developed. No preliminary derivatisation of the sample is necessary. The separation is completed in 6 minutes.
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  • 71
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    Chromatographia 14 (1981), S. 507-509 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Headspace ; Phenol ; Urine ; Enzymatic hydrolysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A new method has been developed for the determination of phenol in urine in which the phenol conjugates are hydrolysed enzymatically and the liberated phenol is analysed by headspace chromatography. The results compare favourably with those obtained by the method of van Haaften and Sie in which acid hydrolysis is carried out in a heated GC precolumn. The enzymatic hydrolysis headspace technique appears to be very reliable and does not suffer from the disadvantages of precolumn acid hydrolysis.
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  • 72
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    Chromatographia 14 (1981), S. 421-424 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Liquid sulfur ; McReynolds' constants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The McReynolds' constants for liquid sulfur as a stationary phase in gas-liquid chromatography (GLC) are presented. A simple graphical method of pattern analysis is used to indicate the uniqueness of the sulfur column as compared with other stationary liquid phases characterized by McReynolds. The limitations of using a single factor (as polarity) for the basis for the selection of GLC columns is discussed.
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  • 73
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Kováts retention indices ; Propellants ; Solvents ; Aerosol packs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary A gas chromatographic method is described by which a nearly complete separation of all commonly used propellants and solvents and their identification and determination can be achieved in one step. The separation is by simple adsorption chromatography on columns packed with Porapak-T with a temperature program 100–180°C at 10°C/min. Kováts' retention indices have been calculated for isothermal conditions at 150°C respectively 100°C for the propellants, at 180°C for the solvents. An exact identification of the propellants and solvents by means of the Kováts' indices is practicable even in complex mixtures.
    Notes: Zusammenfassung Es wird eine gas-chromatographische Methode angegeben, welche eine fast vollständige Auftrennung aller handelsüblichen Aerosol-Treibgase und Lösungsmittel und ihre Identifizierung und Bestimmung in einem Schritt gestatet. Die Trennung erfolgt durch reine Adsorptions-Chromatographie and Porapak T-Säulen bei 100–180°C mit einer Temperaturate von 10°C/min. Zur Bestimmung der Retentionsindices nach Kovats wurden die Treibgase isotherm bei 150°C bzw. 100°C, die Lösungsmittel bei 180°C aufgetrennt. Anhand der Kovats-Indices ist eine eindeutige Identifizierung der Treibgase und Lösungsmittel selbst in vielfältigen Gemischen möglich.
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