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  • Articles  (141)
  • paleolimnology  (54)
  • Triticum aestivum  (34)
  • Electron microscopy  (28)
  • Coleoptera  (25)
  • Springer  (141)
  • 1980-1984  (141)
  • 1925-1929
  • 1983  (141)
  • 1
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    Colloid & polymer science 261 (1983), S. 373-374 
    ISSN: 1435-1536
    Keywords: Electron microscopy ; short-time staining ; nodular structure ; crystallization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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  • 2
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    Entomologia experimentalis et applicata 34 (1983), S. 291-296 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Curculionidae ; Cyrtobagous ; Salvinia weevil ; Feeding characteristics of larvae ; Development of larvae ; Plant nutrition ; Temperature effects on development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Après leur naissance, les larves de Cyrtobagous sp. passent de 1 à 4 jours à brouter les racines, et de 0 à 9 jours dans les bourgeons de la plante hôte, Salvinia molesta, avant d'y creuser une galerie dans le rhizome. Bien que les larves aient été capables de survivre jusqu'à 38 jours en broutant les racines, quant elles furent privées de rhizome, elle ne purent achever leur développement. Quand les galeries furent commencées, le développement larvaire, entre 21° et 31°, dépendit de la température et de la teneur en azote de l'hôte. Les larves ne se développèrent pas à 17°. Une haute valeur nutritive de l'aliment consommé par les larves réduisit la durée du développement, mais n'influença pas la durée ultérieure de leur développement nymphal. Les lieux de prise de nourriture et les dégâts produits par des larves isolées furent précisés.
    Notes: Abstract Newly-emerged larvae of a salvinia weevil, Cyrtobagous sp. spent from 1–4 days browsing on the roots and from 0–9 days in the buds of the host plant, Salvinia molesta, prior to tunnelling into the rhizome of this aquatic weed. Although larvae were able to survive up to 38 days browsing on roots when rhizomes were withheld, they were unable to complete development. After tunnelling began, larval development between 21° and 31° was dependent on temperature and nitrogen levels in the host. Larvae failed to develop at 17°. High nutritional intake by the larvae reduced larval development time but did not influence duration of their subsequent pupal development. The feeding sites and plant damage produced by individual larvae were assessed.
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  • 3
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    Entomologia experimentalis et applicata 34 (1983), S. 124-126 
    ISSN: 1570-7458
    Keywords: Negret ; Melanic mutant ; X-linked mutation ; Flour Beetle ; Tribolium confusum ; Coleoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 4
    ISSN: 1570-7458
    Keywords: Storage pests ; Coleoptera ; Bostrichidae ; Prostephanus truncatus ; (±)-1-methylbutyl (E)-2-methyl-2-pentenoate ; Rhyzopertha dominica ; (±)-1-methyl-butyl (E)-2,4-dimethyl-2-pentenoate ; Dominicalure ; Aggregation pheromone ; Monitoring
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les réponses de Prostephanus truncatus Horn (Coleoptera: Bostrichidae) à deux constituants de la phéromone d'agrégation de Rhyzopertha dominica Fabricius (Coleoptera: Bostrichidae), le (±)-1-méthylbutyl (E)-2-méthyl-2-penténoate et le (±)-1-méthylbutyl (E)-2,4-diméthyl-2-pentéoate, connus comme “Dominicalure 1” et “Dominicalure 2”, ont été étudiées au laboratoire et au champ. Auslaboratoire ces composés ont été essayés individuellement et en mélange 1:2. Une membrane de caoutchouc imprégnée de phéromone a été utilisée comme émetteur lent, et une courbe de réponse en fonction de la dose a été établie. P. truncatus répondait plus vigoureusement à la Dominicalure 2 seule. Tous ces traitements ont été comparés dans un essai aux champs en Tanzanie, dans lesquels des pièges en carton ondulé contenant des diffuseurs de phéromone étaient placés dans des entrepôts de maïs dans les fermes. La Dominicalure 1 et le mélange de 1 et 2 étaient tous deux efficaces pour piéger R. dominica. La Dominicalure 2 a piégé plus de P. truncatus que les autres traitements et était à peu près aussi efficace que le contrôle visuel pour détecter la présence de cet insecte dans les stocks. On peut envisager que la Dominicalure 2 pourrait servir de base à un programme pour lutter contre P. truncatus en Afrique de l'Est.
    Notes: Abstract Laboratory and field studies have been made of the responses of Prostephanus truncatus (Horn) to two components of the aggregation pheromone of Rhyzopertha dominica (Fabricius) — (±)-1-methylbutyl (E)-2-methyl-2-pentenoate and (±)-1-methylbutyl (E)-2,4-dimethyl-2-pentenoate, known as “Dominicalure 1” and “Dominicalure 2” respectively. In the laboratory, these compounds were tested individually and as a 1:2 mixture; P. truncatus responded most strongly to Dominicalure 2 alone. All three treatments were compared in a field trial in Tanzania to monitor both R. dominica and P. truncatus in farm stores. Dominicalure 1 or a mixture of 1 and 2 were both highly effective for trapping R. dominica. In contrast, Dominicalure 2 trapped more P. truncatus than the other treatments and was about as effective as visual inspection at demonstrating the presence of the beetle in stores. Dominicalure 2 could form the basis of a monitoring programme for P. truncatus in East Africa.
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  • 5
    ISSN: 1432-0983
    Keywords: Allomyces macrogynus ; Mitochondrial DNA ; Electron microscopy ; Restriction enzyme map
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The mitochondrial (mt) DNA of the aquatic phycomycete Allomyces macrogynus is a circular molecule with a size of 56.1 kbp. The cleavage sites for the restriction enzymes SalI and PvuI were mapped by comparing the partial denaturation patterns of isolated restriction fragments with the pattern of the intact circle. The genes coding for the small and large ribosomal RNA (rRNA) were located on the restriction map by heteroduplex and R-loop analysis. The gene coding for the large rRNA contains an intervening sequence, app. 0.7 kbp in size, near the 3′-end of the gene. The two rRNA genes are encoded on the same strand of the mtDNA and separated by a region of 17–18 kbp. This rRNA gene organization is similar to that found with members of the Ascomycetes.
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  • 6
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    Archives of microbiology 135 (1983), S. 169-175 
    ISSN: 1432-072X
    Keywords: Photosynthetic membranes ; Electron microscopy ; Image processing ; Ectothiorhodospira halochloris ; Ectothiorhodospira abdelmalekii ; Rhodopseudomonas viridis ; Rhodopseudomonas sulfoviridis ; Thiocapsa pfennigii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The photosynthetic membranes of the five bchl b-containing bacteria Ectothiorhodospira halochloris, E. abdelmalekii, Rhodopseudomonas viridis, R. sulfoviridis and Thiocapsa pfennigii have been investigated by electron microscopy and digital image analysis. All five species have the photosynthetic complexes hexagonally arrayed in the membrane with lattice spacings close to 13 nm, except for R. sulfoviridis and T. pfennigii which display somewhat smaller (∼12.5 nm) lattice spacings. Correlation averaging which imposes less stringent requirements on the lattice perfection than conventional Fourier filtration techniques has been employed to elucidate the structure of the photosynthetic complexes. Their basic organization, i.e. a ring, probably containing the light-harvesting (LH) polypeptides, surrounding a core (the “reaction centre”) appears to be almost identical for all species under scrutiny. Despite a resolution of ∼1.6 nm, however, little further significant substructure can be deduced from the averages; possible reasons for the “blurred” appearance of the LH-ring and absence of any subdivision in the reaction centre are discussed along with strategies aimed at obtaining a more detailed model of the molecular architecture of the photosynthetic membranes.
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  • 7
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    Archives of microbiology 135 (1983), S. 25-29 
    ISSN: 1432-072X
    Keywords: Electron microscopy ; Euglena mutabilis ; Flagellate ; Photomovement ; Photoreceptor ; Phototaxis ; Single-cell analysis ; Videomicroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Due to the lack of an emergent flagellum the green flagellate Euglena mutabilis is restricted to gliding motility. During forward movement, the organisms orient positive phototactically in the presence of a suitable light stimulus. The cell contains both a stigma and a paraflagellar body which differ in shape and size from the organelles found in E. gracilis. The degree of orientation in white light follows an optimum curve with a maximum at about 100 lx. The spectral sensitivity shows a number of prominent peaks in the blue and green regions and extends well into the red region of the visible spectrum. Since the cell does not rotate during locomotion a periodic shading mechanism cannot account for phototactic orientation. Thus, phototaxis in the related species, E. gracilis and E. mutabilis differ in their photoreceptor molecules, their sensory transduction chains and their strategies of light direction detection.
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  • 8
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    Journal of chemical ecology 9 (1983), S. 1449-1464 
    ISSN: 1573-1561
    Keywords: Coleoptera ; Dytiscidae ; Agabus seriatus ; Agabus obtusatus ; defensive secretions ; steroids ; regeneration ; pygidial glands ; prothoracic glands ; cholesterol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The defensive secretions of the dytiscid species,Agabus seriatus (Say) andAgabus obtusatus (Say), were qualitatively and quantitatively analyzed by high-pressure liquid chromatography. The intrinsic ability ofA. Seriatus andA. Obtusatus to regenerate their prothoracic gland defensive secretions under laboratory conditions was determined by analyzing the secretions every seventh day for five weeks. Both beetles regenerated ∼ 80% of their prothoracic gland components within two weeks.A. seriatus was injected with [4-14C]cholesterol and after a three-week regeneration period 7.5% of the14Clabel was found in the steroidal defensive secretion from the prothoracic glands.
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  • 9
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    Journal of chemical ecology 9 (1983), S. 1533-1541 
    ISSN: 1573-1561
    Keywords: Aggregation pheromone ; attractant ; 1-methylcyclohex-2-en-1-ol ; Dendroctonus pseudotsugae ; Coleoptera ; Scolytidae ; bark beetle ; Douglas-fir beetle ; 3-methylcyclohex-3-en-1-ol ; Pseudotsuga menziesii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract 1-Methylcyclohex-2-en-1-ol (1,2-MCH-ol) was synthesized, identified as a compound found in volatiles of the female Douglas-fir beetle, and shown by bioassays to be an aggregation pheromone. 1,2-MCH-ol matches in both GC retention index and mass spectrum a compound released by the female after feeding. 3,3-MCH-ol was also synthesized as a candidate compound; its mass spectrum is presented because published mass spectra are incorrect for this compound. Synthetic 1,2-MCH-ol increased arrestment and stridulation of males in olfactory walkways and increased trap catches of flying beetles. Males were more responsive to 1,2-MCH-ol than females.
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  • 10
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    Journal of chemical ecology 9 (1983), S. 181-190 
    ISSN: 1573-1561
    Keywords: Coleoptera ; Buprestidae ; Cerambycidae ; Cleridae ; Scolytidae ; wood-boring beetles ; bark beetles ; ethanol ; host attractants ; hardwood tree insects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Ethanol, methanol, acetone, and acetaldehyde—chemicals identified in the inner bark of living trees—were used to bait vane traps placed in crowns of oak trees in Connecticut. Ethanol-baited traps caught more cerambycid, scolytid, and clerid beetles than unbaited traps. Buprestidae were not attracted to ethanol. Acetaldehyde and acetone were not attractive to any family. A mixture of ethanol, methanol, and acetaldehyde was no more attractive than ethanol alone. The vane traps were very effective at catching Cerambycidae and Scolytidae, but ineffective compared to sticky panels at catching Buprestidae.
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  • 11
    ISSN: 1573-1561
    Keywords: Coleoptera ; Scolytidae ; bark beetle ; Ips paraconfusus ; aggregation pheromone ; enantiomer ; electrophysiology ; electroantennogram ; interruption ; allomone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Antennae of male and femaleIps paraconfusus were equally and highly sensitive to their male-produced, multicomponent aggregation pheromone. Female and male antennae were highly sensitive to the pheromonal component, (S)-(−)-ipsenol, but essentially insensitive to its antipode, (R)-(+)-ipsenol. Further, female and male antennae were more sensitive to the pheromonal component, (S)-cis-verbenol, than to its antipode, (R)-cis-verbenol. Dramatic sexual dimorphism in chiral sensitivity to the ipsdienol enantiortiers was found, with female antennae being more sensitive to the conspecific pheromonal enantiomer, (S)-(+)-ipsdienol, and male antennae being more sensitive to the antipode, (R)-(−)-ipsdienol. Since (R)-(−)-ipsdienol is the principal pheromone of CaliforniaIps pini and interruptsI. paraconfusus aggregation, male antennae appear to be more sensitive to an interspecific allomone than a conspecific pheromone. Of the conspecific pheromonal enantiomers, both male and female antennae were most sensitive to (S)-(+)-ipsdienol, intermediately sensitive to (S)-(−)-ipsenol, and least sensitive to (S)-cis-verbenol. However, when enantiomeric sensitivities were compared to the estimated concentrations of these components in the natural pheromone, (S)-(~)-ipsenol tended to equal or approach the potency of (S)-(+)-ipsdienol as an antennal stimulant, while antennal responsiveness to (S)-cis-verbenol was dramatically less than for the other two pheromonal components. The behavioral implications of such physiological sensitivities are discussed in regard to perception of multicomponent synergistic pheromones and the relative efficacy of each component as an orientation cue.
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  • 12
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    Journal of chemical ecology 9 (1983), S. 585-606 
    ISSN: 1573-1561
    Keywords: Coleoptera ; Scolytidae ; bark beetle ; Ips paraconfusus ; pheromone ; enantiomer ; electrophysiology ; electroantennogram ; interruption ; allomone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The antennal sensitivities of both male and femaleIps paraconfusus were found generally to be greatest for conspecific aggregation pheromones (ipsdienol, ipsenol); intermediate for an additional conspecific pheromone (cis-verbenol), an aggregation synergist (2-phenylethanol), and pheromones/allomones of sympatric species (trans-verbenol, verbenone, and frontalin); and lowest for both host terpenes (alpha-pinene and myrcene) and other bark beetle-produced odorants (exo-brevicomin and linalool). Of the enantiomeric compounds tested, antennae of both sexes did not differ in sensitivity between thetrans-verbenol enantiomers at low dosage levels; but at higher dosages, the conspecific-produced enantiomer, (1R,4S,5R)-(+)-trans-verbenol, elicited larger mean EAG responses than its antipode, (1S,4R, 5S)-(−)-trans-verbenol. At the mid-dosage range, female antennae tended to be slightly more responsive to (S)-(−)-verbenone than to (R)-(+)-verbenone, while male antennae were equally responsive to stimulations by either verbenone enantiomer. In field bioassays there was a large and significant reduction in trap catches ofI. paraconfusus on traps where the (S)-(−)- or (R)-(+)-enantiomers of verbenone were evaporated beside logs containing boring conspecific males. Only when the (S)-(−)-enantiomer of verbenone was evaporated beside logs containing boring males did the sex ratio ofI. paraconfusus trapped shift from female-dominated to male-dominated attraction. Thus both physiological and behavioral data suggest a differential chiral sensitivity of female beetles for the verbenone enantiomers. The relative sensitivities between different chiral compounds derived from one or the other of the common precursoral host terpenes, (S)-(−)- and (R)-(+)alpha-pinene or myrcene, are discussed.
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  • 13
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    Journal of chemical ecology 9 (1983), S. 13-31 
    ISSN: 1573-1561
    Keywords: Aleochara curtula (Goeze) ; Coleoptera ; Staphylinidae ; tergal gland secretion ; defense ; mating stimulants ; female sex pheromone ; hydrocarbons ; n-aldehydes ; substituted 1 ; 4-benzoquinones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract At high concentrations, the defensive tergal gland secretion (TGS)3 of the staphylinid beetle,Aleochara curtula, inhibits the male copulatory response (grasping with parameres). Inhibitory chemicals, for which a function as alarm substances is assumed, aren-undecane, 1-undecene,n-dodecanal, toluquinone, and 2-methoxy-3-methyl-1,4-benzoquinone. When emitted in small amounts, however, the TGS releases the male grasping response. The main components with aphrodisiac effect are (Z)-4-tridecene,n-dodecanal, and (Z)-5-tetradecenal. These supplementary mating stimulants, which are not sex specific, work synergistically with the aphrodisiac female sex pheromone from thé epicuticular lipids and are discussed as alerting pheromones of short-term effect. Antennal movements of resting males as an indication of the recognition of a female and the approach to the mate are released at somewhat longer distances, when the TGS is additionally present.
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  • 14
    ISSN: 1573-1561
    Keywords: Scolytus multistriatus ; S. scolytus ; Coleoptera ; Scolytidae ; elm bark beetle ; multistriatin stereoisomers ; Dutch elm disease ; aggregation pheromone ; field responses ; attractant baits
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The field responses of English populations of the Dutch elm disease vectors,Scolytus multistriatus andS. scolytus to baits containing 4-methyl-3-heptanol, a host synergist [(−)-α-cubebene or (−)-limonene] and (±)-α-, (+)-β-, (−)-β-, (±)-γ-, or (±)-δ-multistriatin were examined. (±)-α-Multistriatin, released at 5–10 μg/day, enhanced the response ofS. multistriatus to baits containing 4-methyl-3-heptanol and either of the host synergists but had no effect on the capture ofS. scolytus. The release of larger amounts (57 or 365 μg/day) of (±)-α-multistriatin interrupted the response of both species to the 4-methyl-3-heptanol baits. It appears that α-multistriatin has multiple functions as a behavior-modifying substance for the two beetles. The (+)-β-, (−)-β-, (±)-γ-, and (±)-δ-multistriatins were inactive when released at 5–10 μg/day. The results of these field experiments suggest that one bait can be formulated to capture both species.
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  • 15
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    Journal of chemical ecology 9 (1983), S. 397-422 
    ISSN: 1573-1561
    Keywords: Cruciferae ; chemical defense ; gradient ; glucosinolate ; herb-ivory ; insect-plant interactions ; Cardamine cordifolia ; Coleoptera ; Chrysomelidae ; Homoptera ; Psyllidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Insect use of native crucifers may be related to patterns in mustard oil content. Consequently, in 1979 we measured glucosinolate content of Rocky Mountain bittercress,Cardamine cordifolia (Cruciferae), using paper and gas chromatography, in relation to: plant organ, phenology, elevation, habitat, leaf position and weight, and plant consumption by two adapted insect herbivores. Results for each are as follows. (1) The predominant constituent in all vegetative organs was 2-butylglucosinolate; concentration of isothiocyanate-yielding glucosinolates (IYG) was highest in roots (1.11 mg/gfr. wt) and lowest in stems (0.07 mg/g). (2) Concentration of IYG appeared to be higher in plants lacking oxazolidinethione-yielding glucosinolates (OYG) than in those with OYG. (3) Terminal cauline leaves had a higher content of IYG than leaves in other positions on a plant. (4) Heavy leaves had significantly higher concentrations of IYG than did lighter leaves. (5) IYG concentrations were not directly related to elevation. (6) Leaves of plants occurring naturally in the sun had concentrations of IYG similar to those of plants in the usual shaded habitat. However, experimental removal of overhanging willows caused a significant, stress-induced increase in IYG concentrations. Finally, (7) feeding by two adapted herbivores, chrysomelids and psyllids, was associated with lower, rather than higher, IYG concentrations. The results demonstrate significant variation in glucosinolate content in a native crucifer and suggest that some of this variation can be partitioned in relation to the ecological and environmental axes examined.
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  • 16
    ISSN: 1573-1561
    Keywords: Cryptolestes ferrugineus ; rusty grain beetle ; aggregation ; pheromone ; macrolide ; (E,E)-4,8-dimethyl-4,8-decadien-10-olide ; (3Z,11S)-3-dodecen-11-olide ; (Z,Z)-3,6-dodecadien-11-olide ; (Z)-5-tetradecen-13-olide ; 11-dodecanolide ; 4-nonanolide ; Coleoptera ; Cucujidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Two synergistic macrolide aggregation pheromones were isolated from Porapak Q-trapped volatiles obtained from the frass ofCryptolestes ferrugineus (Stephens). These compounds were identified as (E,E)-4,8-dimethyl-4,8-decadien-10-olide (I) and (3Z,11S)-3-dodecen-11-olide (II) and given the trivial names ferrulactone I and II, respectively. Analysis of captured volatiles from separated male and female adults disclosed that the pheromones are male-produced. Additional macrolides were identified in frass volatiles, but were devoid of any pheromonal activity. The structures of I and II were confirmed by comparison with synthetic materials.
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  • 17
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    Journal of chemical ecology 9 (1983), S. 657-672 
    ISSN: 1573-1561
    Keywords: Pseudoplusia includens ; soybean looper ; Lepidoptera ; Noctuidae ; Epilachna varivestis ; Mexican bean beetle ; Coleoptera ; Coccinellidae ; feeding preferences ; nutrition ; food utilization ; host-plant resistance ; induced resistance ; glyceollin ; isoflavonoids ; soybean ; phytoalexins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Effects of soybean phytoalexins on the feeding of the soybean looper and Mexican bean beetle were investigated to test the hypothesis that phytoalexins might be a defense mechanism of plants against insects as well as against pathogens. Short-term behavioral responses to the phytoalexins were analyzed using dual-choice tests with phytoalexin-rich and phytoalexin-poor (control) tissues. Phytoalexin production was elicited with ultraviolet radiation. Results from the dual-choice tests indicated that 6th instar soybean looper larvae fed equally on the control and phytoalexin-rich tissues. Feeding by adult and 4th instar Mexican bean beetles, however, was strongly deterred by the phytoalexins as evidenced by “single-bite” mandible scars on the phytoalexin-rich cotyledon discs. Nutritional effects of the isoflavonoid phytoalexin glyceollin on early instar soybean looper larvae were tested by incorporating the phytoalexin into an artificial medium at a level of 1% dry weight (0.15% fresh weight). The larvae were reared for 7 days from emergence on diets of control and glyceollin-containing media. Although survival on the glyceollin diets was initially less than on the control diets, under the experimental conditions glyceollin had no significant effect on the growth, development, or subsequent survival of the larvae. Efficiency of food utilization (ECI) was reduced, indicating that the phytoalexins may be a mild digestibility-reducing factor for the loopers. Implications of the results for host-plant resistance are discussed.
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  • 18
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    Journal of chemical ecology 9 (1983), S. 1353-1361 
    ISSN: 1573-1561
    Keywords: Canavanine ; Caryedes brasiliensis ; Coleoptera ; Bruchidae ; Dioclea megacarpa ; plant-insect interactions ; amino acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Larvae of the bruchid beetle,Caryedes brasiliensis (Bruchidae) have the ability to avoid significant incorporation ofl-canavanine, the guanidinooxy structural analog ofl-arginine, into de novo synthesized proteins. This ability is related to a highly discriminatory protein-synthesizing system which exhibits marked ability to avoid processing an array of nonprotein amino acids structurally related to arginine.
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  • 19
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    Theoretical and applied genetics 66 (1983), S. 101-109 
    ISSN: 1432-2242
    Keywords: Anther culture ; Culture temperature ; Induction frequency ; Pollen callus (plantlet) ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The response of anther culture to culture temperature was studied in detail using many varieties, F1 hybrids and pollen-derived lines of wheat (Triticum aestivum) as materials. The suitable culture temperature for inducing pollen callus (or embryoids) in wheat anther culture ranged from 26 °C to 30 °C, varying with genotypes. But for the great majority of wheat genotypes the suitable culture temperatures lay between 28 °C and 30°C. The most significant genotypic variation in the response to culture temperature was observed in the comparison between the culture at 33 °C for eight days followed by culture at 25 °C (or 26 °C) and the continuous culture at 25 °C (or 26 °C). This genotypic variation in the response to culture temperature is a heritable character which may be controlled by multiple genes. The effect of culture at 30 °C for eight days followed by culture at 26 °C was similar to, or in some cases, better than that of continuous culture at 28 °C, and the effect of culture at 32 °C for eight days followed by culture at 28 °C was similar to that of continuous culture at 30 °C. In the range from 26 °C to 32 °C, the overwhelming majority of pollen calli emerged before the 40th day after anther inoculation, and the higher the culture temperature, the earlier and more concentrated the emerging period of the pollen callus. The pollen callus obtained at high temperatures above 28 °C should be transferred in time onto the regeneration medium at 25°–27°C to induce shoots.
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  • 20
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    Theoretical and applied genetics 64 (1983), S. 255-258 
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; Wheat ; Malate dehydrogenase ; Chromosomal location
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The malate dehydrogenase (E.C. no 1.1.1. 37) of Triticum aestivum L. cv. Chinese Spring, shows two activity zones. The results obtained support the hypothesis that the malate dehydrogenase isozymes of zone II are dimers composed of the six possible combinations of subunits coded by triplicate genes located in the long arms of chromosomes of the homoeologous group 1.
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  • 21
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    Theoretical and applied genetics 66 (1983), S. 111-121 
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; Agropyron ; Intergeneric hybrids ; Embryo culture ; Chromosome pairing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Intergeneric hybrids of Triticum aestivum (2n=42,AABBDD) with Agropyron ciliare (2n= 28,SSYY), A. trachycaulum (2n=28,SSHH), A. yezoense (2n=28,SSYY) and A. scirpeum (2n=28) are reported for the first time. F1 hybrids of T. aestivum were also produced with A. intermedium (2n=42,E1E1E2E2Z1Z1) and A. junceum (2n=14,JuJu). All wheat-Agropyron hybrids were obtained by embryo rescue technique. Cultivars and reciprocal crosses differed for seed set, seed development and F1 plant production. The F1 hybrids were sterile. Attempts to obtain amphiploids were unsuccessful. However, backcross derivatives were obtained with wheat as the recurrent parent. The level of chromosome pairing in A. trachycaulum x wheat, A. yezoense x wheat and wheat x A. junceum hybrids provided no evidence of homologous or homoeologous pairing. Mean pairing frequencies in A. ciliare x wheat, wheat x A. scirpeum and wheat x A. intermedium hybrids indicated homoeologous or autosyndetic pairing. Ph gene was more effective in regulating homoeologous pairing in A. yezoense x wheat hybrids than in A. ciliare x wheat hybrid. Chromosome pairing data of BC1 derivatives indicated that either some of the wheat chromosomes were eliminated or Agropyron chromosomes caused reduced pairing of wheat homologues.
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    Theoretical and applied genetics 65 (1983), S. 41-46 
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; Wheat ; Protein ; Mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Poor adaptability or functional quality of much germplasm used for breeding high-protein hard red winter wheats prompted mutagenesis as an alternative means of increasing grain protein content. Four hard red winter wheat genotypes — KS644 (‘Triumph// Concho/Triumph’), ‘Kaw’, ‘Parker’, and ‘Shawnee’ — were treated with 0.40 M ethyl methanesulfonate (EMS). Advanced lines (M8-M10) were selected that had a 3-year mean grain protein advantage of 0.7% to 2.0% over controls. Increased grain protein content was generally associated with decreased grain yield and kernel weight, but some high-protein mutant lines had yields or kernel weights similar to those of original genotypes. Changes in height and lodging induced by EMS were generally favorable, most mutants being shorter and lodging less than controls, but blooming date was generally delayed, a deleterious change. One line also changed from resistant to segregating for wheat soil-borne mosaic virus. Mutant lines might be utilized in cross-breeding programs, particularly if negative pleiotropic effects and linkages are absent.
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  • 23
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    Theoretical and applied genetics 64 (1983), S. 97-101 
    ISSN: 1432-2242
    Keywords: Common wheat ; Triticum aestivum ; Electrophoresis ; Endosperm proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Total endosperm protein subunits, extracted from the common wheat cultivar Chinese Spring and from some of its aneuploid lines, were fractionated according to their molecular weight (MW) in an improved high resolution one-dimensional sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis (PAGE). The resolution obtained by this method and, in particular, that of the high molecular weight (HMW) glutenin and gliadin subunits approached that of a previous report in which two-dimensional fractionation system based on charge and MW was used. In the cultivar Chinese Spring, 21 discrete protein bands were resolved and the chromosomes controlling many of them were either reconfirmed, or, in some cases, established. The advantages of this high resolution SDS PAGE technique are discussed.
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    Theoretical and applied genetics 67 (1983), S. 53-58 
    ISSN: 1432-2242
    Keywords: Aegilops umbellulata ; Genetics ; Lectin ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Each of the three genomes in hexaploid wheat controls the expression of a specific lectin in the embryo. The chromosomes which control their synthesis were determined using nullisomic-tetrasomic and inter-varietal chromosome substitution lines of ‘Chinese Spring’. All three wheat lectins were shown to be controlled by the homoeologous group 1 chromosomes. Using ditelosomic lines of ‘Chinese Spring’ the lectin genes could be localized on the long arms of chromosomes 1A and 1D. Inter-specific addition and substitution lines of Aegilops umbellulata chromosomes to ‘Chinese Spring’ indicated that chromosome 1U, which is homoeologous to the group 1 chromosomes of wheat, controls lectin synthesis.
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  • 25
    ISSN: 1432-2242
    Keywords: HMW glutenin subunit genes ; cDNA clones ; Tandem DNA repeats ; Chromosomal location ; Gene copy number ; Wheat ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary cDNA clones encoding wheat HMW glutenin subunits have been isolated from a cDNA bank made to poly A+ RNA from developing wheat endosperm var. Chinese Spring. One such clone, pTag 1290, has enabled us to identify the HMW glutenin mRNA species. The DNA sequence of this clone has been partially determined and it contains several tandem DNA repeats. The sequence is discussed in relation to the generation of the HMW glutenin subunit gene family. Analysis of the organization of the HMW glutenin sequences in the wheat genome revealed that the genes encoding HMW glutenin subunits exist in low copy number and are located on the long arm of each of the homoeologous group 1 chromosomes.
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  • 26
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; T. timopheevii ; Wheat ; Photoperiod ; Vernalization ; Male sterility ; Alloplasmic hybrids
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    Topics: Biology
    Notes: Summary Studies were conducted to determine the influence of the male sterility-inducing cytoplasm of Triticum timopheevii (Zhuk.) Zhuk. on response of several common winter wheat (T. aestivum L.) nuclear genotypes to photoperiod and vernalization. Comparative studies of cytoplasmic substitution lines provide information on the role of the cytoplasmic genetic mechanism in growth and development. In the case of cytoplasmic male sterility-based hybrid production systems, ubiquity of sterility-inducing cytoplasm in derived hybrids warrants thorough characterization of its influence on plant phenotype. Factorial combinations of cytoplasm (T. timopheevii and T. aestivum), nuclear genotype, and photoperiod or vernalization treatments were evaluated under hydroponic conditions in controlled environment chambers. Interaction of cytoplasm, photoperiod, and nuclear genotype was significant in one or more experiments for days to anthesis and potential spikelet number, and interaction of cytoplasm, vernalization, and nuclear genotype was significant for days to spike emergence. Long day length was associated with increased percentage seed set in one study, but interactions of photoperiod and cytoplasm were not detected for percentage seed set. Interactions involving cytoplasm and photoperiod or vernalization were interpreted as evidence of the existence of genetic factors in cytoplsam of T. timopheevii which alter photoperiod or vernalization responses of alloplasmic plants relative to responses exhibited by euplasmic plants. Since photoperiod and vernalization responses are critical to adaptation, T. timopheevii cytoplasm can alter adaptability of T. aestivum. The specific effect would be nuclear genotype dependent, and does not appear to be of a magnitude greater than that induced by nuclear genetic variability at loci conditioning photoperiod or vernalization responses or other adaptation-determining characteristics. Normal multilocation/year testing of alloplasmic hybrids should therefore adequately identify zones of adaptation.
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    Theoretical and applied genetics 66 (1983), S. 77-86 
    ISSN: 1432-2242
    Keywords: Common wheat ; Triticum aestivum ; Electrophoresis ; Endosperm proteins ; Glutenins ; Gliadins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Endosperm protein subunits of 109 primitive and modern lines of hexaploid wheat, Triticum aestivum L. em. Thell., were fractionated by one-dimensional, high resolution, sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis (PAGE). A wide range of both qualitative and quantitative variation was observed in the fractions of the high molecular weight (HMW) glutenin and gliadin subunits of the different lines. The qualitative variation was expressed in the number of subunits per fraction and in their molecular weight, as determined by the differential rate of migration. The quantitative variation was expressed in the differential staining intensity of several subunits. The widest variation was detected in the HMW glutenin and gliadin subunits controlled by chromosome 1B while a much smaller variation was observed in those subunits controlled by chromosome 1A and further smaller variation in the subunits controlled by 1D. Only a small number of subunits in both fractions was found to be controlled by chromosome 1A indicating that diploidization of endosperm protein genes in common wheat has been non-random. The genetic and evolutionary implications of these findings are discussed.
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    Theoretical and applied genetics 66 (1983), S. 1-7 
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; Aegilops species ; Alloplasmic lines ; 2D gel electrophoresis ; Cytoplasmic inheritance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In this first analysis the protein patterns obtained by two-dimensional gel electrophoresis of 8 day-old leaves from 18 alloplasmic wheat lines are compared. From 440 spots retained on the basis of their reproducibility, 36 proteins were observed to vary in different cytoplasms, allowing us to distinguish the T. aestivum cytoplasm from 5 Aegilops cytoplasms. Twenty-four of the 36 variable proteins could be structurally related to the large subunit of RuBPCase. Nuclear variation between 3 wheat varieties was observed for 14 proteins.
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    Cell & tissue research 234 (1983), S. 469-496 
    ISSN: 1432-0878
    Keywords: Bone marrow (human) ; Neutrophil granulocyte ; Granules ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Bone marrow from hematologically healthy adults was exposed to a number of fixation procedures for investigation of the heterogeneity of the granule population in neutrophil granulocytes at the ultrastructural level. Four main cell stages were distinguished: early promyelocyte, late promyelocyte, myelocyte, and mature neutrophil granulocyte and described separately; metamyelocytes and band-form or stab cells are described together. The characteristic changes in the cytoplasm during myelopoiesis were analysed quantitatively. Special attention was given to the development of the granule population. Three types of granule arise in successive cell stages: granules which develop a sub-structure in the matrix (nucleated granules) are formed in early promyelocytes, granules with a homogeneous electron-dense matrix (azurophil granules) in late promyelocytes, and granules with a less electron-dense matrix (specific granules) in myelocytes. The three types of granule remain present during myelopoiesis. The best results in distinguishing the granule types were obtained by prefixation either in 0.1% glutaraldehyde or in 1.5% glutaraldehyde followed by washing in phosphate-buffered Ringer solution to which aminotriazole had been added. Granule counts revealed for the mature neutrophil a total number of granules of about 220 per ultrathin section. This population of granules is composed of about 12% nucleated, 11% azurophil, and 77% specific granules. When our previous findings are taken into account, the existence of three successively formed and morphologically distinguishable types of granule in heterophil (neutrophil) granulocytes has been demonstrated for three mammalian species: the guinea pig, the rat, and man. A separate term for the early promyelocyte stage is proposed: eomyelocyte.
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    Cell & tissue research 234 (1983), S. 579-593 
    ISSN: 1432-0878
    Keywords: Rods ; Cones ; Retina ; Bullfrog ; Synapse ; Electron microscopy
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    Topics: Biology , Medicine
    Notes: Summary Lumps of electron-dense material were observed in synaptic clefts associated with all types of photoreceptors, in the vicinity of the synaptic ribbons, in the retinae of dark-adapted frogs. Frogs were reared under a cyclic illumination (light on at 8:00; light off at 20:00) and then exposed to one of two courses of dark adaptation: one started from 11:00 in the morning, and the other started from 20:00 in the evening. The synaptic clefts of red rods became wider at some places where spherical or polygonal lumps of dense material were accumulated. The frequency and sectional area of the lumps increased faster for the first hour in the regime starting from 20:00 than in the regime starting from 11:00, then they reached the similar saturation levels of about 0.6 (per ribbon) and 1.6 to 1.8×104 (nm2) in both the regimes. In greenrod synapses, plate-shaped lumps of dense material were present in synaptic clefts and interspaces between the processes of second-order neurons. In cone synapses at the end of about 1 h darkness, the frequency and area of the lumps reached maximum values of about 0.12 (per ribbon) and 9×103 (nm2) in the regime starting from 11:00 and, about 0.08 (per ribbon) and 4 × 103 (nm2) in the regime starting from 20:00. On exposure to light, the dense material abruptly disappeared from all types of photoreceptor synaptic clefts. Large dense-core vesicles, occasionally observed in light-adapted rod photoreceptor terminals, seem to participate in exocytosis of the dense material. The number of dense-core vesicles per synaptic ribbon in a terminal was about 0.55 at the end of 3 h light in the morning and about 1.28 at the end of 12 h light in the evening. The increased number of dense-core vesicles during the daytime may contribute to the faster accumulation of dense material in the synaptic clefts. Although the chemical identification or the functional significance of the electron-dense material remains unknown, it is interesting that this material showed a rise and fall in response to darkness and illumination. Also the fact that this material is clearly visible will be helpful for future analysis of frog photoreceptor synapses.
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    Cell & tissue research 232 (1983), S. 593-600 
    ISSN: 1432-0878
    Keywords: Peritrophic membrane ; Insect ; Microvilli ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A double plasma membrane (DPM) surrounding intestinal microvilli of the migratory milkweed bug, Oncopeltus fasciatus, is described. Mutant and wild types of the phytophagous insect have been studied by conventional SEM and TEM procedures with the use of membrane-enhancing staining methods. Longitudinal and transverse sections revealed a DPM surrounding microvilli and continuing over the apical portions of the intestinal cell. The outer membrane of the DPM contributes to an intestinal lining or peritrophic membrane (PTM), which apparently accumulates in layers. SEM studies reveal a rugose intestinal surface and complete PTM in both starved and fed insects. Only rarely are exposed microvilli seen by SEM. SEM examinations also enable the observation of numerous blebs on the luminal side of the PTM apparently held in position by a neck-like attachment and apparently derived from the outer membrane of the DPM. Preliminary TEM studies of microvilli revealed unique microvesicle-like structures, lying just inside the inner membrane of the DPM, which may be of membrane origin based on their typical trilaminar appearance after en bloc staining with uranyl acetate. Highly ordered microfilaments were observed to occupy the most central aspect of the microvilli.
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    Cell & tissue research 234 (1983), S. 125-134 
    ISSN: 1432-0878
    Keywords: Vasopressin ; Immunocytochemistry ; Electron microscopy ; Hypothalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Vasopressin-containing neurons, identified by immunocytochemistry, are located predominantly in the posterior magnocellular division of the paraventricular nucleus of the rat hypothalamus. By electron microscopy, the immunoreaction product is seen within the cell bodies and neuronal processes. In the perikarya and dendritic processes, the immunoreactive material is associated primarily with neurosecretory granules. Axonal processes, identified by their content of microtubules and accumulation of neurosecretory granules, show the immunoreaction product in association with both of these organelles. Afferent axo-dendritic, axo-somatic and putative axo-axonic synapses with immunostained vasopressinergic neurons can be identified. The presynaptic profiles do not contain immunoreactive material. This study contributes to the ultrastructural characterization of vasopressinergic neurons in the paraventricular nucleus and of their afferent synaptic input.
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  • 33
    ISSN: 1432-0878
    Keywords: Dictyosome-like structures ; Golgi apparatus ; Phosphatidylcholine ; Laminated figures ; Electron microscopy ; Guinea pig
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    Topics: Biology , Medicine
    Notes: Summary Dictyosome-like structures (DLS) of guinea pig spermatocytes, when prefixed in mixtures of glutaraldehyde and tannic acid, exhibited laminated figures with a repeating periodicity of about 4.5 nm in the spaces between DLS saccules or in association with the surfaces of the DLS saccules. These laminated figures were similar to those figures derived from saturated lipids in other tissues. Alternatively, spaces between saccules were collapsed leaving only thin, electron-dense material separating adjacent saccules. These changes were not observed when the DLS were prefixed in glutaraldehyde before exposure to tannic acid. The presence of laminated figures following fixation with tannic acid and osmium tetroxide suggests that saturated lipids are present in, or associated with, the intersaccular regions of the DLS. The distribution of laminated figures in other membrane structures was not affected by post fixation with tannic acid nor were laminated figures comparable to those of the DLS observed between cisternae of the Golgi apparatus. These results support previous conclusions that DLS are distinct from Golgi apparatus and are a unique component of the germ cell cytoplasm.
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  • 34
    ISSN: 1615-6102
    Keywords: Digestion ; Membrane flow ; Electron microscopy ; Sarcodina ; Actinophrys sol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The digestion of food in the heliozoonActinophrys sol is characterized by several distinct membrane events. Initially, extrusomes expand and fuse with each other and with the plasma membrane providing the membrane for the nascent food vacuole. During this process a—presumably lytic—material is secreted. After complete forming of the food vacuole a second type of vesicles fuses with it, whereupon usually lysis of the prey occurs. After denaturation and coagulation of the food, fluid is removed from the food vacuole. This process is accompanied by a high cytotic activity around the periphery of the food vacuole. Following this step, the perinuclear Golgi region shows an active appearance and numerous lysosomes fuse with the food vacuole. In consequence of this the food is degradated. The food vacuole shrinks continuously. Simultaneously vesicles filled with the digested material pinch off from the food vacuole, the content of which shows a more and more condensed mass of undigestible material. The undigestible residues are defecated eventually. The process of digestion is accompanied by an increase in volume and number of electron lucent cytoplasmic vacuoles. These vacuoles gradually become filled with a filamentous material starting with the vacuoles in the cell periphery. As the digestion continues, the vacuolar contents become condensed successively. Synchroneously the vacuoles move towards the cell center. After completion of the digestion, the cytoplasmic vacuoles decrease in volume and number and do not show any longer electron dense contents.
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    Protoplasma 115 (1983), S. 104-113 
    ISSN: 1615-6102
    Keywords: Cereals ; Embryo culture ; Triticum aestivum ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cell proliferation from the mature embryo of wheat occurs on a defined medium in the presence of 2,4-D. Unorganized growth is observed when the 2,4-D concentration is equal to or greater than 2 mg/l, but increasing levels of 2,4-D inhibit cell division. Cell divisions begin after 4 days in culture from parenchyma cells within and near the procambial tissues of the embryo axis. By day 8 continuous meristematic zones are formed in association with vascular tissues, and DNA synthesis and cell divisions are distributed throughout these zones. No morphological evidence exists to show that these zones consist of proliferating root primordia, which are formed only after the level of 2,4-D falls below some critical concentration. When the concentration of 2,4-D is lowered, the meristematic zones first become dissected and then give rise to many root meristems.
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  • 36
    ISSN: 1615-6102
    Keywords: Anacystis nidulans ; Cyanobacterium ; Electron microscopy ; Freeze-fracmres ; Thylakoid degradation ; Ultrathin-sections
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Photooxidative bleaching of the CyanobacteriumAnacystis nidulans was studied by electron microscopic investigation of both freezefractured and thin-sectioned samples. During bleaching four consecutive phases in degradation of photosynthetic membranes (thylakoids) could be characterized: 1. No ultrastructural changes until photosystem II activity is lost. 2. Derangement of characteristic arrangement of thylakoids. 3. Thylakoids visible only in thin-sectioned but not in freeze-fractured samples. 4. Completely bleached cells, only traces in place of former thylakoids visible in thinsectioned samples. Bleaching did not cause lysis of the cells showing that the cytoplasmic membrane was not damaged. Polyhedral bodies also were still detectable in bleached cells.
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    Protoplasma 116 (1983), S. 198-200 
    ISSN: 1615-6102
    Keywords: Chromosome isolation ; Electron microscopy ; Vicia faba ; Vicia narbonensis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Using a formalin fixation technique whole chromosomes from root tips ofVicia species were isolated into a buffer solution. Combining this technique with the use of a set of reciprocal translocations available for this species—Vicia faba— allowed each member of the karyotype to be isolated and identified. Such isolated chromosomes can be used for optical microscopy or for either transmission or scanning electron microscopy where critical point drying clearly reveals chromatin fibre.
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    Protoplasma 116 (1983), S. 209-212 
    ISSN: 1615-6102
    Keywords: Parapharyngeal mass ; Electron microscopy ; Cytochemistry ; Electron microprobe X-ray analysis ; Ciliate ; Homalozoon vermiculare
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The structure and elemental composition of the granules which make up the parapharyngeal mass of the ciliateHomalozoon vermiculare are analyzed. The mass is made up of two kinds of granules. One is not membrane-bounded and is composed of paraglycogen. The second type is comprised of concentric lamellae. It is rich in magnesium, phosphorus, potassium, and calcium. These results do not support the contention that the granules are directly involved in the process of food vacuole formation. The role of the parapharyngeal mass remains obscure.
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  • 39
    ISSN: 1615-6102
    Keywords: Cell walls ; Electron microscopy ; Moisture ; Plastic embedding ; Seeds
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    Topics: Biology
    Notes: Summary Aqueous fixatives caused dry seed tissues to swell; mashed peanuts, crushed to remove oil, swelled even more. Use of anhydrous, organic solvents as vehicles for fixatives enabled maintenance of dimensional stability during fixation of dry seed tissues; even crushed seed tissue did not swell significantly when processed anhydrously. However, anhydrously processed specimens proved difficult to section. The difficulty was due to imperfect permeation of plastic into the seed tissues during embedding. An explanation of why anhydrously processed dry seed tissues are so difficult to embed in plastic is offered.
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  • 40
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    Euphytica 32 (1983), S. 217-223 
    ISSN: 1573-5060
    Keywords: Hexaploid triticale ; Secale cereale ; rye ; Triticum aestivum ; wheat ; heterochromatin ; chromosome association
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary In the hexaploid triticale (× Triticosecale Wittmack) cultivar Rosner chromosome 2R lacks the prominent heterochromatic bands of both telomeres. This modified 2R chromosome is capable of pairing in a high frequency with wheat chromosomes. It is hypothesized that the accumulation of heterochromatin at the telomeres of rye chromosomes may have contributed to the isolation of the wheat and rye genera by inhibiting pairing between wheat and rye chromosomes.
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    Euphytica 32 (1983), S. 431-438 
    ISSN: 1573-5060
    Keywords: Hordeum vulgare ; barley ; Triticum aestivum ; wheat ; T. turgidum ; durum wheat ; X Triticosecale ; triticale ; salt tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Saline soils are typically very patchy in their salinity. The yield of crops growing on them is similarly patchy. This paper argues that because most of the yield from such soils comes from the least saline areas, the best breeding strategy for improving the overall yield of crops growing on them is to select for high yield on non-saline soils. This conclusion derives from comparing the effects that four different breeding goals, namely: (1) a 10% increase in yield on non-saline soils, (ii) a 20% increase in the threshold salinity that first reduces yield, (iii) a doubling of yield at an electrical conductivity of the saturation extract (ECe) of 20 dS/m and (iv) a combination of (i) and (iii), would have on total yield. The effects of achieving these goals in barley, common wheat, durum wheat and triticale in fields exhibiting different salinities are predicted from actual yields of these species grown on different salinities in the field.
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  • 42
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; kernel color ; protein content ; inheritance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Utilization of high-protein hard red wheat germplasm in breeding high-protein hard white winter wheats for the U.S. Great Plains raised concern regarding possible genetic relationships between kernel color and protein content. Segregating F3 and F4 populations from reciprocal crosses and backcrosses involving high-protein hard red winter wheat cultivar Plainsman V and normal-protein hard white winter wheat line KS75216 were examined. Nonsignificant regression and correlation coefficients in the F3 generations of KS75216/Plainsman V, KS75216//KS75216/Plainsman V and Plainsman V//KS75216/Plainsman V indicated the absence of genetic relationships between kernel color and protein content. Therefore, despite the presence of genes for protein content and kernel color on the same chromosomes (3A, 3B and 3D), kernel color and protein content appeared as independent traits. A small but significant negative relationship between white kernel color and high protein in Plainsman V/KS75216 was attributable to the possible presence of alien genetic material in the parentage of Plainsman V. Chi-square tests indicated that Plainsman V is a mixture of genotypes for kernel color; most genotypes carry two dominant genes for red color and a few carry one or three. Genetic control of grain protein appeared to be complex. Partial dominance for high protein was indicated in the F3 generation but a generally continuous distribution and transgressive segregation also suggested other genes functioned additively. Heritability estimates by parent-offspring (F3-F4) regression were sufficiently high to ensure genetic progress in the selection of high-protein lines in the red x white wheat crosses. We concluded that development of high-protein cultivars is as feasible for white wheats as for red wheats.
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    Euphytica 32 (1983), S. 299-310 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; bread wheat ; ear colour ; glume colour ; genetics ; linkage ; chromosomal location ; geographical distribution ; homeoallelic genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A summary of the brown ear character of bread wheat is presented. In most varieties this character is conditioned by a (semi)dominant gene identified as Rg on 1BS. This gene seems to be widespread, from the viewpoint of evolution, probably because it is an ‘old’ gene. There are no indications that the presence of the gene and hence the presence of a brown ear is advantageous or disadvantageous to the carrier wheat plant. Some linkage relations are described. More research is needed to establish whether all varieties with one gene for brown ear carry Rg, to investigate the varieties with a non-monogenic genetic system and to identify more associations between brown ear and other characters. It should also further be investigated whether within T. spelta another gene for brown ear is present and, if so, whether this gene is on chromosome 1AS and linked to Hgl, the gene for hairy glume.
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    Euphytica 32 (1983), S. 743-748 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; plant physiology ; plant breeding ; Australia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Major changes in the behaviour of the Australian wheat crop over the last one hundred years have been associated with three major gene groupings. The significance of major genes in monitoring response to vernalization, photoperiod and gibberellin, reveals a more optimistic future for breeding programmes where simple genetic and physiologic studies are integrated within those programmes. A revised classification of growth habit is presented in the appendix.
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  • 45
    ISSN: 1573-5036
    Keywords: Acetic acid ; Inhibition ; Wheat growth ; Tillering ; Root growth ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Studies were conducted to determine the effect of and duration of the effect of alliphatic acids on winter wheat (Triticum aestivum L.) seedling root growth, shoot growth, and tillering. Winter wheat seedlings grown in contact with unbuffered solutions of 2 mM or greater acetic or 0.5 mM or greater propionic or butyric acid for 3 days showed decreased root and, in general, shoot growth. Buffering the medium partially alleviated the problem. Removing the seedling from the acid medium and growing it in a nutrient medium resulted in accelerated root growth, compared with the control, while shoot growth was permanently inhibited during this study. Seedling wheat, grown with one root in contact with concentrations of acetic acid ranging from 0–16 mM and the other roots in aliphatic acid-free medium, grew at the same rate as the control. Seedling wheat grown for 3 days in 2 and 4 mM acetic acid medium showed a more rapid formation of the first stem tiller (T1) than did the control. Concentrations of 6 and 8 mM acetic acid appeared to delay T1 tiller formation through the first 18 days after germination, while only 10 mM acetic acid reduced T1 tiller formation by 30% 20 days after germination. The second stem tiller (T2) was not affected by previous exposure to acetic acid. The results of these laboratory studies indicate that short-term exposure of seedling winter wheat to short-chain aliphatic acids can result in permanent shoot and tiller damage and not in permanent root damage as previously thought. These results could explain the poor performance of no-till seeded winter wheat when growing through heavy crop residues that are producing shortchain aliphatic acids during decomposition.
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  • 46
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    Plant and soil 70 (1983), S. 391-402 
    ISSN: 1573-5036
    Keywords: Intercropping Lupins ; Lupinus albus ; Manganese ; Nitrogen ; Phosphorus ; Triticum aestivum ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Significant interactions between wheat and lupins occur below ground and wheat intercropped with lupins has access to a larger pool of available P, Mn and N than has wheat grown in monoculture. This suggests that the wheat is able to take up nutrients produced or made available by lupins grown in association with it.
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  • 47
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    Plant and soil 71 (1983), S. 463-467 
    ISSN: 1573-5036
    Keywords: Anion uptake ; Barley ; Hordeum vulgare ; Mycorrhiza ; Phosphorus ; pH Rhizosphere ; Triticum aestivum ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary In two field experiments sown in 1982 to test the effect of vesicular-arbuscular mycorrhizas (VAM) on growth and phosphorus nutrition of (i) spring wheat and spring barley, (ii) winter wheat and winter barley, we measured the concentrations of the major cation (K+, Ca2+, Mg2+ and Na+) and anions (Cl−, SO4 2−, H2PO4 − and NO3 −) in shoot tissue. In all cases the sum of the anion concentrations (ΣA) was increased strongly by mycorrhizal infection but not by P additions, confirming earlier observations2 on spring wheat. The concentration of total cations (ΣA) was generally reduced by P additions, hence P and VAM both reduced the cation excess (ΣC−ΣA) but by different mechanisms. These results suggest that increased uptake of anions by plants with VAM may be a general phenomenom which would have important implications for the elemental composition of crops. The effect may also be manifested by other types of mycorrhizal association.
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  • 48
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    Plant and soil 75 (1983), S. 51-61 
    ISSN: 1573-5036
    Keywords: Aggregate fractions ; Fatty acids ; Long-term rotation ; Triticum aestivum ; Water-stable aggregates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Three non-replicated, unfertilized, dryland grain rotations—continuous wheat, wheat-fallow, and wheat-wheat-fallow—were established in 1912 on a Dark Brown Chernozemic (Typic Haploboroll) soil. The effect of long-term cropping on the chemical constituents of total water-stable aggregates was assessed. There was a loss in percentage of total water-stable aggregates and a shift in aggregate size distribution with time. Together with an increase in the 100 μm diameter fraction, there was an increase in the sand component of this fraction. These sand particles are probably held together by alkaline-soluble, acid-insoluble organic matter. Organic carbon, polysaccharides, polyuronides, phenols, and chloroform/methanol-extractable organic matter were all associated with the 〉250 μm diameter fractions. Although the aggregates had generally the same suite of aliphatic carboxylic acids, the relative proportions changed with cultivation.
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  • 49
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    Euphytica 32 (1983), S. 593-600 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; bread wheat ; Triticum durum ; durum wheat ; Secale cereale ; inbred lines ; intergeneric crossability ; embryo development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Crossability and embryo development were studied in the crosses of one Triticum aestivum and three T. durum genotypes with nineteen rye inbred lines. Parental wheat and rye genotypes exerted a significant influence on the characters seed set, number of seeds containing embryos and viable plantlets obtained from embryo culture. It was established that the common winter wheat cultivar Götz is of intermediate crossability. The rye inbred lines varied substantially in their capacity to fertilize several wheat genotypes. Interactions between wheats of different crossability classes and their seed set with rye lines were detected. Significant correlations were obtained between seed set and viable plantlets recovered in vitro.
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  • 50
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; protein content ; grain yield ; mixing time ; soil-borne mosaic virus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The wheat (Triticum aestivum L.) cultivar Lancota has genetic potential to produce grain with higher protein content than most other cultivars grown in the hard winter wheat region. It has not consistently expressed full potential for grain protein content outside its area of development. Experiments were conducted to determine genetic variability for grain protein content in Lancota and to utilize that variability to select genotypes with high grain protein content. Approximately 1600 lines were screened to 37 high-protein selections that varied in yield, test weight, flour mixing time, blooming date, height, and reaction to wheat soil-borne mosaic virus (WSBM). Nine promising selections (KS80476, KS80478, KS80480, KS80488, KS80490, KS80491, KS80497, KS80499, and KS80500) had grain protein advantage over Lancota of 0.5 to 1.0% and equalled or exceeded Lancota in yield or test weight. Those selections were resistant to WSBM and satisfactory or better in mixing properties than Lancota. The highest protein selection (KS80496) had a mean protein advantage of 1.5% over Lancota but exhibited a short mixing time of 1 7/8 min. The absence of correlation between some years indicated strong environmental influence on protein content. We concluded that adequate genetic variability existed in the high-grain protein cultivar Lancota to select lines that express the high protein potential better than the original cultivar outside its area of development.
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  • 51
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; linkage drag ; seedling resistance ; Puccinia graminis tritici ; stem rust ; Puccinia recondita ; leaf rust ; Puccinia striiformis ; yellow rust ; stripe rust
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary To determine whether linkage drag had occurred during the breeding of near isogenic lines (NILs) of wheat, 176 lines involving 11 sets of NILs, their recurrent parents and some of their donors were tested for seedling reaction to stem rust (4 races), leaf rust (3 races) and yellow rust (3 races). From the results, six cases were identified in which linkage drag may have played a role. More research is needed to prove clearly that linkage is involved. Nevertheless, the results suggest that linkage drag is a fairly common phenomenon.
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  • 52
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat, glutenin ; high-molecular-weight subunits ; SDS-PAGE ; SDS-sedimentation test ; baking quality selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The high-molecular-weight subunit composition of glutenin is regulated by genes on the long arm of the homoeologous group 1 chromosomes. Evidence is presented that in general the bread-making quality of wheat cultivars containing the subunits 3+10 coded for by chromosome 1D or the subunit 2* coded for by chromosome 1A is higher than that of cultivars containing their allelic counterparts the subunits 2+11 or subunit 1 and the null form respectively. Besides it is shown that the positive effects of the subunits 3+10 and subunit 2* are additive.
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  • 53
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; bread wheat ; Triticum turgidum ; Hordeum vulgare ; barley ; chemotypes ; electrophoresis ; variation ; prolamines ; gliadins ; hordeins ; electrophoregram ; genetic resources
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Polyacrylamide gel electrophoresis (PAGE) of storage proteins (prolamines) was used to screen 64 landraces of wheat and barley from Nepal and the YemenArab Republic and two cultivars for comparison. Altogether 3168 single seeds were examined and the advantages gained by using the vertical slab gel method were recognised. The extent of variation present within populations of landraces could be assessed easily and rapidly using the methods described. Differences in ploidy levels of wheats were detected by PAGE and investigated. Suggestions are made for improvements in sampling strategies in hilly terrain.
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  • 54
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    Hydrobiologia 106 (1983), S. 43-57 
    ISSN: 1573-5117
    Keywords: eutrophication ; paleolimnology ; diatoms ; sediment chemistry ; peatland management
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Stratigraphy of diatoms and chemistry in the surface sediment deposited at 35 m depth in Lake Polvijärvi was studied. The existence of annual laminations or varves in the sediment allowed a precise dating of the profile. Diatoms were analysed in 0.5 cm sequences; from 0 to 16.0 cm continuously and then intermittently every fourth 0.5 cm down to 44.0 cm. Sediment chemistry (loss-on-ignition, C, N, Fe, Mn, Mg, P, chlorophyll and carotenoids) was analysed from sediment surface down to 10.5 cm of altogether 33 subsamples, each containing 1–3 varves, and spanning the period 1921–1980. From 4.5 cm depth upwards the diatom concentration strongly increases, and the plankton diatom succession from Tabellaria flocculosa through Asterionella formosa to Melosira ambigua and Fragilaria crotonensis reflects a marked eutrophication of the lake. This algal succession occurs in pace with an increase in sediment accumulation rate and changes in sediment chemistry, which indicate increased allochthonous inputs and enhanced algal production in the lake. The change of the lake ecosystem is contemporaneous with extensive peatland draining and fertilizing that was carried out on its watershed during the past two decades. Existing chemical data from a number of lakes situated within the drainage area prove that at present the treated peatlands are the main source of nutrient loading of Lake Polvijärvi. A former period with indications of slightly increased productivity of the lake was dated by varve counting to AD 1690–1910 (35–12 cm). This period (characterised by Asterionella formosa) may coincide with that of the slash-and-burn cultivation in the area.
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    Hydrobiologia 103 (1983), S. 45-51 
    ISSN: 1573-5117
    Keywords: paleolimnology ; magnetism ; dating ; Australia ; North America ; Japan ; Europe ; Near East
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Paleolimnomagnetic records from five regions of the world have been combined with historical magnetic field observations in order to produce regional geomagnetic master curves.
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  • 56
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    Hydrobiologia 103 (1983), S. 141-146 
    ISSN: 1573-5117
    Keywords: paleolimnology ; lakes ; sediments ; eutrophication ; Cladocera ; Switzerland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Species composition and density of cladoceran populations changed in Lakes Zürich, St. Mortiz and Baldegg as human populations increased in these watersheds. Lake Zürich sediments became annually laminated in the 1890's as a result of increased organic input as the size of the cities surrounding the lake grew. At the same time, the Bosmina species changed from a oligotrophic form (longispina) to a eutrophic form (longirostris). An increase in Daphnia spp. populations also occurred at this time in the lake's history. Bosmina longispina reappeared in the lake in 1965 as the lake's trophic status changed from eutrophic to mesotrophic due to effective sewage treatment facilities. Annual laminations appear in the Lake St. Moritz sediments about 1910. Shortly thereafter, a shift from B. longispina to B. longirostris occurred. This change in trophic status is associated with increased tourism in the area. Lake Baldegg sediments also show annual laminations beginning in 1885 and a similar shift in the Bosmina species. Other cladoceran remains were too scarce to be useful in interpreting the histories of these lakes.
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  • 57
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    Hydrobiologia 103 (1983), S. 37-44 
    ISSN: 1573-5117
    Keywords: paleolimnology ; magnetic minerals ; sediment sources
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This review outlines the origin and environmental significance of magnetic minerals in lake sediments. Attention is drawn to situations where the patterns of mineral magnetic variation is a reflection of processes other than changing erosion rates and fire incidence. The use of mineral magnetic techniques in sediment source tracing, palaeoclimatic studies and the reconstruction of particulate pollution history is illustrated by means of case studies from Britain and N. America. The value of magnetic susceptibility as an on-site core logging technique is shown by reference to data from Lake Washington.
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  • 58
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    Hydrobiologia 103 (1983), S. 53-58 
    ISSN: 1573-5117
    Keywords: paleolimnology ; secondary ferrimagnetic oxides ; S.I.R.M. ; magnetic susceptibility ; laminated sediments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The magnetic parameters S.I.R.M. and magnetic susceptibility have been used to try and establish the fire histories of lake drainage basins. The technique is demonstrated using sediments from three lakes: Llyn Bychan (N. Wales), a lake with a recently burnt catchment, Lake Biscarrosse (S. W. France), a lake with a well documented fire history, and Lake Laukunlampi (E. Finland), a lake with laminated sediments and a long, but unknown fire history.
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  • 59
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    Hydrobiologia 103 (1983), S. 59-64 
    ISSN: 1573-5117
    Keywords: paleolimnology ; sedimentation pattern ; magnetic susceptibility ; Scanian lakes ; palaeomagnetism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Magnetic susceptibility measurements have been used to correlate synchronous depths in ca. 50 l m. cores of recent sediment from a small lake (area ca. 55 ha) in Scania, southern Sweden. The three-dimensional picture of sediment accumulation which emerges provides a basis for studying sediment deposition patterns through time. Using a palaeomagnetic chronology, the results show that the pattern and rate of accumulation have dramatically altered during the past 350 years, thus making semiquantitative studies of downcore sediment properties in a single core problematical. Possible reasons for these phenomena are briefly discussed.
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  • 60
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    Hydrobiologia 103 (1983), S. 65-69 
    ISSN: 1573-5117
    Keywords: paleolimnology ; X-ray radiography of sediment cores ; sedimentary properties ; sediment accumulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract X-ray radiographs of unextruded sediment cores are used for the documentation and the interpretation of primary and secondary sedimentary structures, and for the correlation of synchronous laminations between different cores. The vertical variation in bulk density, water content and void ratio, and the increase of solids with increasing sediment depth are calculated from the recorded film density along the radiographs. The X-ray radiographic technique for the study of sedimentary properties is fast and non-destructive. The technique is especially valuable when studying the uppermost part of the sediment cover and the processes of sediment redistribution and sediment accumulation. Studies are being undertaken in several Swedish lakes and coastal bays, where mono- and stereoradiographs are being used to classify bottom and sediment types, to interpret changes in the depositional environment, and to calculate past and present rates of sediment accumulation.
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  • 61
    ISSN: 1573-5117
    Keywords: paleolimnology ; sediment core positioning ; hydrographic survey ; computer contouring ; morphometric calculation
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    Topics: Biology
    Notes: Abstract Automated techniques for sediment core site positioning, hydrographic survey, and contour mapping are described. The computer contouring system can be extended to calculate values for morphometric variables such as maximum length (1max), maximum width (wmax), lake perimeter (10), lake area (A) and lake volume (V). The techniques are exemplified using results from Augher Lough, Northern Ireland.
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  • 62
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    Hydrobiologia 103 (1983), S. 75-79 
    ISSN: 1573-5117
    Keywords: paleolimnology ; Dead Sea climate ; pore-waters ; diffusion ; sediments ; salinity ; porosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The salinity of lakes is subject to variations imposed by climatic changes. These variations are recorded in the salinity profile of pore waters. Meromictic lakes, such as the Dead Sea, are a special case where waters which underlie the mixolimnion reflect salinity variations. In a sediment core from Dead Sea shallow waters, the salinity profile exhibited a minimum at about 1.9 m depth. It is shown by a diffusion model that this minimum can be attributed to lower salinities which prevailed at the sediment water interface for several decades around the turn of this century. No such minimum was observed in a sediment core from the deepest part of the lake where, during the last two centuries, the overlying brines had a constant salinity.
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  • 63
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    Hydrobiologia 103 (1983), S. 81-84 
    ISSN: 1573-5117
    Keywords: paleolimnology ; geochemistry ; trace elements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A geochemical study of lacustrine sediments was undertaken as part of a major paleolimnological project concerned with the impact of man on lakes. Factor analysis was applied to the geochemical data obtained from a core from one lake. Three principal factors which explained most of the variance of the initial data were identified. Factor I is related to the organic:mineral component ratio of the sediment, and can be considered as an indirect index of change in lake trophic status through time. Factor II is related to the granulometric composition of the sediment and matches evidence for changes in the hydrological regime of the lake. Factor III reflects changes in redox potential and is more closely related to processes occurring within the lake than other factors. Specific geochemical associations of elements are connected with each factor and are the factor indicators. The correlation of these associations are analyzed as geochemical indices of the variability of sediment accumulation conditions in time.
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  • 64
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    Hydrobiologia 103 (1983), S. 91-97 
    ISSN: 1573-5117
    Keywords: paleolimnology ; diatoms ; assemblage indicators ; Finland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Diatom assemblages from the topmost sediment of 49 lakes were ordinated by means of a program for detrended correspondence analysis and reciprocal averaging (Decorana). Five lake groups were separated, each having more or less characteristic diatom assemblages and water quality. Shifts from one group to another caused by factors such as acidification, artificial drainage, diffuse nutrient loading and sewage are discussed.
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    Hydrobiologia 103 (1983), S. 85-90 
    ISSN: 1573-5117
    Keywords: paleolimnology ; diatoms ; East Africa ; transfer functions ; pH-indicators
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    Topics: Biology
    Notes: Abstract Our purpose is to establish the quantitative relationship between recent diatom floras and ecological parameters, in order to extrapolate the results to the past. The parameter pH is here considered as an example. This work is based on the study of about I60 diatom samples from East Africa and of their corresponding biotopes. We propose some statistical methods to interpret the data. Correspondence analysis allows us to define the pH-indicator species. The regression calculations allow pH values to be calculated using the percentage of the diatom species in a sample.
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  • 66
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    Hydrobiologia 103 (1983), S. 99-102 
    ISSN: 1573-5117
    Keywords: paleolimnology ; organic matter ; bacteria ; aerobic decomposition ; oxygen consumption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The investigations were carried out in lakes situated in the forest zone (Karelian Isthmus, Baltic zone, South Ural) and in the forest-steppe (South Ural) of the USSR. The lakes differ in their bioproductivity and in the intensity of their human influence. The amount of organic matter accumulating in the sediments is closely related to production and decomposition processes in the trophogenic layer. Processes of organic matter transformation were found to be most active in the uppermost sediment. The quantity of bacteria shows no correlation with the organic matter content of the sediment. Increase in organic matter, up to 70–80% of dry weight, is often accompanied by a decrease in bottom bacteria. The intensity of aerobic decomposition of the labile organic matter can be judged from the oxygen demand of the sediments. However, it is important to differentiate between chemical and biological oxidation processes. The quantity of bottom bacteria correlates closely with the value of oxygen consumption only in cases of high sediment redox potentials.
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  • 67
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    Keywords: paleolimnology ; sedimentary pigments ; primary production ; core analyses
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    Topics: Biology
    Notes: Abstract A statistically significant correlation of the type y = axb between sedimentary plant pigments and contemporary algal primary production has been found in a study of the recent trophic evolution of twelve Italian lakes. The equation is used to assess baseline production levels in periods (50–70 years ago) when human influence was low.
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    Hydrobiologia 103 (1983), S. 107-111 
    ISSN: 1573-5117
    Keywords: paleolimnology ; lake ontogeny ; lake succession ; eutrophication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Paleolimnologists frequently invoke the term ‘eutrophication’ for describing apparent enrichment phases in the history of a lake. I argue that this term is often used incorrectly and that alternative explanations can serve as more accurate descriptions. Increased organic content in the sedimentary record may result from increased nutrient availability (eutrophication), but it can also reflect decreased residence time of water, or changes in biotic interactions, or changes in lake morphometry. Additionally, I argue that ‘eutrophication’ is an inappropriate term for describing the aging process of lakes. Lake ontogeny is the preferred term, as it does not imply directional changes in nutrients, nor in community structure.
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  • 69
    ISSN: 1573-5117
    Keywords: paleolimnology ; lakes ; eutrophication
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    Notes: Abstract Problems relating to the disappearance and eutrophication of lakes as a result of human activity are presented. A study area was selected located in an agricultural/forest region where human influence on lakes used to be minimal. In the past 25 years a number of lakes have completely disappeared and others have become rapidly enriched. Human interference has included: the pulling down of water mills, drainage and river canalisation, construction of holiday resorts, development of intensive farming, increased mineral fertilization, and the extension of roads and road traffic.
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    Hydrobiologia 103 (1983), S. 177-179 
    ISSN: 1573-5117
    Keywords: paleolimnology ; sediment chemistry ; heavy metals ; ATP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This investigation is concerned with the impact of industrial and municipal waste discharge on lakes near the city of Tampere, Finland. The record of P, Zn and ATP in the recent sediments of Vanajavesi I, a polluted lake, and Mallasvesi, a largely unpolluted lake, are compared.
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    Hydrobiologia 103 (1983), S. 169-175 
    ISSN: 1573-5117
    Keywords: paleolimnology ; Chironomidae ; subfossil remains ; shallow lake ; eutrophication ; Lake Balaton
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Lake Balaton, the largest shallow lake in Central Europe, is about 20 000 years old. An enormous increase in tourism and the disproportionate building development of the last few decades has resulted in the acceleration of eutrophication in the lake. Widespread research to reveal the causes of water-quality deterioration and possible ways of protection against it have recently started. The investigation of the larvae of non-biting midges (Diptera: Chironomidae) in the sediment of the open-water zone has also begun. The contemporary faunal composition strongly correlates with the trophic gradient along the longitudinal axis of the lake. We therefore supposed that the eutrophication process should be identifiable from the analysis of subfossil chironomid head capsules from the upper (15 cm thick) layer of the sediment. We found that quantitative results could only be obtained when fragments as well as relatively intact head capsules are considered. Our data verify that the originally oligo-mesotrophic community has been gradually replaced by eutrophic species in a west to east direction. Large-bodied larvae belonging to the Chironomus plumosus group mix the sediment down to 15 cm as they build their tubes and consequently alter the original proportions of head capsules at the different levels. So the sequence of communities through the sediment-layers is not quite reliable.
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    Hydrobiologia 103 (1983), S. 181-184 
    ISSN: 1573-5117
    Keywords: paleolimnology ; Clostridium perfringens ; sewage pollution ; eutrophication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The horizontal and vertical distribution of the gram-positive, non-motile, spore-forming and rod-shaped bacterium Clostridium perfringens Holland was studied. The aim of the study was to estimate the quantity of C. perfringens at different depths of the sediment and evaluate the effect of human effluent which the lake received between 1940 and 1956. C. perfringens lives in the colon of man. Because it is spore forming and cannot multiply under a temperature of 20 °C and, according to the studies of Seppänen et al. (1979) it can be at least 300 years old, it may be a suitable paleolimnological indicator of pollution by human effluent. The results showed that the amounts of Clostridium increased at the same level where redox potential decreased in the sediment due to the beginning of effluent disposal at a depth of 40 mm. The maximum number of Clostridium colonies occurred between 0–30 mm depth.
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    Hydrobiologia 103 (1983), S. 193-198 
    ISSN: 1573-5117
    Keywords: paleolimnology ; Lake Michigan ; geochemistry ; stratigraphy ; Quaternary ; trace elements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The stresses placed on Lake Michigan since the advent of industrialization require knowledge of the sedimentology of the whole lake in order to make informed decisions for environmental planning. Sediment accumulation rates are low: areas of the lake receiving the most sediment average only 1 mm a−1; deep-water basins average 0.1 to 0.5 mm a−1; and large areas are not receiving any sediment. Sediment was deposited rapidly (typically 5 mm a−1), in the form of rock flour, during the deglaciation of both Lake Michigan and Lake Superior Basins. Then the rate of accumulation decreased by 80–90% and has remained relatively constant since final deglaciation. Because active sedimentation occurs mostly in the deep water areas of the lake, the sediment remains undisturbed and contains a record of the chemical history of the lake.
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  • 74
    ISSN: 1573-5117
    Keywords: paleolimnology ; annual laminations ; magnetism ; sediment influx ; sediment chemistry ; eutrophication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The sediments of Loe Pool, a eutrophic coastal lake in south west England, consist largely of laminated clays and clay-gyttjas. Studies of the diatom microstratigraphy of frozen sediment cores from the Pool indicate that the laminations are annual, and that they contain pairs of light and dark bands formed by seasonal variations in the supply of sediment to the Pool from its catchment. Analysis of the magnetic properties of individual laminations demonstrates the presence of physical and mineralogical microstratigraphic variations, which may also be related to seasonality. A varve chronology, which is confirmed by 137Cs analysis and historical records, has been used to provide a timescale for the interpretation of data from other paleolimnological studies. A close agreement between variations in the abundance of sedimentary Sn, and the history of mining in the catchment, has been found. Similarly, analysis of total organic matter, total phosphorus, sedimentary chlorophyll a, sterols, diatoms and Cladocera in the uppermost sediments all indicate eutrophication of the Pool in the period AD 1940 to the present.
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  • 75
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    Hydrobiologia 103 (1983), S. 205-210 
    ISSN: 1573-5117
    Keywords: paleolimnology ; colluvium ; soil chemistry ; clay ; phosphorus loading ; tropical lakes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The long-term impact of Maya culture on a lowland tropical watershed is assessed, using data from a 9.2 m sediment core taken from deep water (28 m) in Lake Quexil. Human population growth, estimated by the 1980 archaeological survey, is associated with a shift in the composition of the sediment to a dominance by inorganic material, the Maya clay formation, beginning ca. 3500 B.P. Increasing settlement densities are correlated with accelerated influxes of phosphorus, carbonates, and siliceous sediment. However, chemical data do not track short-term population fluctuations closely. Because much of the sediment is delivered as colluvium, and not by running water, there is a lag between terrestrial disturbance and impact on the aquatic system. As an indication of this lag, contemporary high sedimentation rates are a residual of Maya activity that virtually ceased some 300–400 years B.P. Comparison of the deep-water core with a shallow-water (7 m) section, based on palynological correlation, reveals only minor differences in proximate chemical composition. Chemical influxes are much higher at the deep-water site, however, as a consequence of sediment focusing in this hyperconical basin. Chemical analyses of soil samples from 21 test pits in the Quexil basin support the principal conclusion that bulk soil movement was the mode of nutrient transfer to the lake, following forest clearance by the Maya.
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  • 76
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    Hydrobiologia 103 (1983), S. 199-203 
    ISSN: 1573-5117
    Keywords: paleolimnology ; clay ; cultural disturbance ; erosion ; Guatemala ; Mayan archaeology ; silt ; particle-size analysis ; tropical lakes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Long-term changes of sedimentary particle-size distribution in two tropical lowland lakes were compared with changes of human population sizes, estimated archaeologically, in the drainage basins. Mean particle size of silt and clay fractions (〈64 µm) varied between 3 and 15 µm. High positive skewness and kurtosis of the distributions were associated with smaller particle sizes; hence small mean size resulted from greater influx of small particles while influx of larger particles was probably constant. An inverse correlation between mean particle size and human population size is interpreted to mean that disturbance-induced erosion results in delivery of very fine inorganic particles at higher rates. Within any one basin, particle-size stratigraphy is more precisely related to archaeological time periods than is pollen stratigraphy. An absolute chronology still eludes us, owing to the failure of 14C dating of calcareous, colluvial sediments, but our relative chronology is now more precise than before. If certain assumptions about past hydrologic relations can be met, particle-size analysis is a way of comparing the histories of geographically very different lakes, including lakes from tropical, temperate, and arctic regions.
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  • 77
    ISSN: 1573-1561
    Keywords: Pissodes strobi ; Pissodes approximatus ; Coleoptera ; Curculionidae ; aggregation pheromone ; grandisol ; grandisal ; Pinus strobus ; white pine weevil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Two related volatile compounds were identified from each of two species ofPissodes bark weevils and implicated as components of their aggregation pheromones. Grandisol (cis-2-isopropenyl-1-methylcyclobutaneethanol), and its corresponding aldehyde, grandisal, were isolated from males of bothP. strobi andP. approximatus and were found in the abdomens and hindguts of the respective species. In field tests synthetic grandisol and grandisal together with odors from cut pine acted synergistically in attracting both sexes ofP. approximatus. This response was similar to that elicited by maleP. approximatus feeding on cut pine. Males and females of natural populations ofP. strobi were more responsive to caged males feeding on leaders of white pine than they were to leaders alone. The combination of grandisol, grandisal, and leaders was less attractive than males on leaders, but more attractive than leaders alone. From isolation of pheromone components at different times of the year, it was determined that males of both species produced grandisol and grandisal only at times when cohort females were reproductively mature.
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  • 78
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    Journal of chemical ecology 9 (1983), S. 129-142 
    ISSN: 1573-1561
    Keywords: Coleoptera ; Scolytidae ; Ips paraconfusus ; bark beetle ; Pinus ponderosa ; ipsenoi ; ipsdienol ; cis-verbenol ; pheromone ; attractant ; intraspecific competition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract About equal numbers of each sex of flyingIps paraconfusus Lanier (Coleoptera: Scolytidae) were caught on traps several meters downwind from a male-infested ponderosa pine log releasing pheromone while a significantly different ratio of over four times more females than males were caught at the pheromone source. Females oriented directly to higher concentrations of colonizing males in a felled tree while males tended to land on the host in adjacent uncolonized areas. The attraction response of walking males to a 1∶1∶1 mixture of the synthetic pheromone components ispenol-ipsdienol-cis-verbenol was reduced progressively at higher concentrations while female response continued to increase. These responses may function to regulate density of colonization and limit intraspecific competition.
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  • 79
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    Journal of chemical ecology 9 (1983), S. 159-180 
    ISSN: 1573-1561
    Keywords: Coleoptera ; Staphylinidae ; Creophilus maxillosus ; defensive secretion ; ant repellent ; bioassay ; isoamyl acetate ; isoamyl alcohol ; iridodial ; actinidine ; dihydronepetalactone ; (E)-8-oxocitronellyl acetate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The abdominal defensive glands ofC. maxillosus secrete a mixture (70μg/beetle) of isoamyl alcohol (I), isoamyl acetate (II), iridodial (III), actinidine (IV), dihydronepetalactone (VE), and (E)-8-oxocitronellyl acetate (X). When disturbed, the beetle everts the glands and revolves the abdomen so as to wipe the glands against the offending agent. Fecal fluid is commonly emitted at the same time and may become added to the glandular material. Ants (Formica exsectoides) are effectively fended off by the beetle and were shown in bioassays (Monomorium destructor) to be repelled by the four major components of the secretion (II, III, X, VE); the principal component (VE) was the most active. Some anatomical features of the glands are described.
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  • 80
    ISSN: 1573-1561
    Keywords: Douglas-fir beetle ; Dendroctonus pseudotsugae ; Coleoptera ; Scolytidae ; electroantennograms ; host selection ; attractants ; aggregation ; 3-methylcyclohex-2-en-1-one ; 3-methylcyclohex-2-en-1-ol ; frontalin ; trans-verbenol ; verbenone ; limonene ; camphene
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Electroantennograms were obtained fromD. pseudotsugae in response to the pheromones 3-methylcyclohex-2-en-1-one (3,2-MCHone), 3-methylcyclohex-2-en-1-ol (3,2-MCHol), frontalin,trans-verbenol, verbenone, and the host terpene hydrocarbons limonene and camphene. Male and female beetles were 10 and 100 times more sensitive to 3,2-MCH-one and 3,2-MCHol than to the other compounds. Of the other compounds, males were most sensitive totrans-verbenol, verbenone, and camphene, while females were most sensitive to frontalin, limonene, and camphene. The results parallel and help explain behavior of individual males and females during host tree selection, aggregation, and colonization.
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  • 81
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    Journal of chemical ecology 9 (1983), S. 1513-1523 
    ISSN: 1573-1561
    Keywords: Coleoptera ; Scolytidae ; Scolytus multistriatus ; European elm bark beetle ; pheromone ; epideictic pheromone ; twig-crotch feeding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The three components of the European elm bark beetle pheromone dispensed from polyethylene vials attached to the boles of healthy juvenile elms affected the rates of beetles landing and twig feeding on the baited trees. Maximum attraction to the tree occurred when all three pheromone components were presented together in a ratio of 1∶1∶8 for 4-methyl-3-heptanol (H), α-multistriatin (M), and α-cubebene (C). M released either alone or in excess of its natural ratio with H and C induced twig-crotch feeding. H presented alone had no effect on attraction or twig-crotch feeding, but in combination with M it induced landing on and boring into the tree bole. We concluded that the ratio of M and H being released influenced incoming beetles either to land on and colonize the bole or to feed in twig crotches. M in excess of H, known to occur when most females are mated, terminates colonization and deflects incoming beetles to crowns of elms.
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  • 82
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    Journal of chemical ecology 9 (1983), S. 201-209 
    ISSN: 1573-1561
    Keywords: Coleoptera ; Dytiscidae ; pygidial glands ; aromatic defensive secretions ; age classes ; seasonal variation ; Agabus bipustulatus ; Agabus paludosus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Aromatic pygidial gland constituents ofAgabus bipustulatus L. andA. paludosus F. were quantitatively determined. Concentration fluctuations were found to be dependent on age and season. Both in quantity and quality of the secretion, young beetles differ from mature beetles by storing only small amounts of gland material with different portions of constituents. Seasonal variations are mainly due to the changing population structure of the species.
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  • 83
    ISSN: 1573-1561
    Keywords: Dendroctonus brevicomis ; Temnochila chlorodia ; Coleoptera ; Scolytidae ; Trogositidae ; western pine beetle ; attractant ; pheromone ; trap ; behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A sticky trap with 3 m2 surface area was modified by changes in attractant release rate, vertical dispersion of the attractant, and addition of a tree trunk silhouette to the trap axis. As attractant release rate increased, the number ofDendroctonus brevicomis caught at the source of attractant and at 1.5 and 5.2 m above ground on two vertical silhouettes 4.5 m away increased. In one experiment, more beetles were caught at a dispersed source of attractant than at a point source. Fewer beetles were caught at the lower traps on the two outlying silhouettes when a silhouette was at the source, than when no silhouette was at the source. As attractant release rate increased, the catch of a predator,Temnochila chlorodia, increased at the source.
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  • 84
    ISSN: 1573-1561
    Keywords: Structure-activity relationships ; pheromone ; Scolytus multistriatus ; Coleoptera ; Scolytidae ; Dutch elm disease ; electroantennogram ; chemoreception ; 4-methyl-3-heptanol ; analogs ; attractant ; aggregation ; beetle ; bark beetle ; alcohols ; ketones ; esters ; epoxides ; carboxylic acids ; amines ; isothiocyanates ; halides ; azides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A number of analogs of the title compound (1), with several different functional groups in place of the 3-OH and with a variety of substituents, were tested for biological acitivity by a laboratory walking-beetle assay. The electroantennogram (EAG) response was determined for many of these, as well. Field tests with baited sticky traps were carried out on compounds with activity in the walking-beetle assay and/or that gave a high EAG response. Structure-activity correlations with parameters reflecting hydrophobic, steric, electronic, and van der Waals interactions with olfactory receptors were examined primarily on the basis of the behavioral tests. Electronic substituent effects on the 3-position functional group and steric effects were found to correlate best. It is suggested that the strength of a hydrogen bond to the 3-oxygen or 3-nitrogen (as proton acceptor) is important in chemoreception by receptors that are involved in the behavioral response.
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  • 85
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    Journal of chemical ecology 9 (1983), S. 803-815 
    ISSN: 1573-1561
    Keywords: Caryedes brasiliensis ; Coleoptera ; Bruchidae ; l-canavanine ; l-canaline ; Dioclea megacarpa (Leguminosae) ; allelochemicals ; detoxification ; adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract This communication reviews recent biochemical studies ofl-canavanine that have provided significant understanding of the interaction between the seed ofDioclea megacarpa (Leguminosae) and the bruchid beetleCaryedes brasiliensis (Bruchidae). The principal biochemical bases are proposed for: canavanine toxicity, the ability of the beetle larvae to adapt to its presence, the metabolic sequestration and detoxification of ammonia, and the potential amplification by microbial symbionts of the beetle's abilities to adapt to toxic components of the host.
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  • 86
    ISSN: 1573-1561
    Keywords: allelopathy ; ferulic acid ; no-tillage ; prickly sida ; common ragweed ; weed control ; 2-methoxy-4-ethenylphenol ; carboxylic acid ; phenol ; morning glory ; Ipomoea lacunosa ; wheat ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract This study was conducted to determine if well-known phytotoxic effects of plant residues on crop growth could also be responsible for observed reductions of certain weed species in no-till cropping systems. An aqueous extract of field-grown wheat (Triticum aestivum L.) reduced the germination and root length of pitted morning glory (Ipomoea lacunosa L.) and common ragweed (Ambrosia artemisiifolia L.). Phytotoxicity was increased by about 70% when bioassays with the wheat extract on morning glory and ragweed were conducted in the presence of light. Phytotoxic substances were extracted from wheat with 2 N NaOH. The hydrolyzed extract was fractionated by thin-layer chromatography (TLC). The compound isolated by TLC having the greatest inhibitory effects on morning glory germination was identified using mass spectrometry and determined to be ferulic acid (4-hydroxy-3-methoxycinnamic acid). Ferulic acid at 5 × 103 M inhibited the germination and root length of morning glory 23 and 82%, respectively, and prickly sida (Sida spinosa L.) with carpels 85 and 82%, respectively. Crabgrass (Digitaria sanguinalis L.) germination was inhibited 100%. Ferulic acid had no effect on ragweed or prickly sida without carpels. Morning glory root and shoot biomass were reduced 52 and 26%, respectively, when morning glory was grown in sand and watered with a 5 × 103 M solution of ferulic acid. Ferulic acid in the presence of prickly sida seed carpels was found to undergo decarboxylation, forming a styrene derivative, 2-methoxy-4-ethenylphenol. The more phytotoxic styrene compound was produced by a bacterium isolated from the carpels of prickly sida seed. The study showed that ferulic acid and other compounds may indeed play a role in reducing the growth of certain weeds in no-tillage cropping systems.
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  • 87
    ISSN: 1573-1561
    Keywords: Coleoptera ; Chrysomelidae ; Diabrotica ; southern corn rootworm ; spotted cucumber beetle ; western spotted cucumber beetle ; sex pheromone ; 10-methyl-2-tridecanone ; ketone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A sex pheromone has been isolated and identified from virgin females of the southern corn rootworm (SCR),Diabrotica undecimpunctata howardi Barber. The synthesized compound, 10-methyl-2-tridecanone was shown to be attractive to males of the SCR, and also to males ofD. u. undecimpunctata Mannerheim, the western spotted cucumber beetle (WSCB), and ofD. u. duodecimnotata in Mexico. Males of both the SCR and the WSCB strongly preferred theR over theS enantiomer. The resolved enantiomers were not tested againstD. u. duodecimnotata.
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  • 88
    ISSN: 1573-1561
    Keywords: Sitophilus zeamais ; Sitophilus granarius ; Sitophilus oryzae ; maize weevil ; granary weevil ; rice weevil ; Coleoptera ; Curculionidae ; aggregation pheromone ; interspecific attraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A dual-choice pitfall bioassay was used to demonstrate the existence of a male-produced aggregation pheromone in the maize weevil. Both males and females showed a highly significant preference for extracts of disks exposed to wheat-feeding males over extracts of disks exposed to wheat kernels only. Neither sex responded significantly to extracts from females. Mating did not reduce pheromone release by males. Response by virgin females to pheromone was significantly higher than response by mated females, but males of either mating status responded equally well. There was no apparent daily periodicity in the responsiveness to pheromone. Rice and maize weevils showed a strong interspecific cross-attraction. Granary weevils of both sexes responded well to maize weevil extracts, but only females showed a significant response to rice weevil extracts. Neither maize nor rice weevils responded significantly to granary weevil extracts.
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  • 89
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    Plant and soil 74 (1983), S. 101-109 
    ISSN: 1573-5036
    Keywords: Crop residue ; Root growth ; Shoot growth ; Soil types ; Temperature ; Triticum aestivum ; Wheat germination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Two controlled environment experiments were conducted to examine the germination and early growth of wheat (Triticum aestivum L. cv. Songlen) growing under crop residues of rape, sorghum, field pea and wheat. Additional treamments also included were soil type (Lithic Vertic Ustochrept and Plinthustalf) and temperature (8°C and 24°C to simulate winter and autumn sowing conditions). At low temperature, wheat and sorghum residues produced the most adverse effects on germination with all residues reducing emergence at high temperatures. Shoot lengths were also reduced by most residues at high temperatures whilst root lengths and shoot and root dry weights were unaffected by residue treatments. These results suggest major phytotoxic effects of residues during early growth (up to 14 days after sowing) with, in general, few interactions with soil type or temperature.
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  • 90
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    Plant and soil 74 (1983), S. 229-235 
    ISSN: 1573-5036
    Keywords: Barley ; Hordeum vulgare ; Mineral composition ; Na−K interaction ; Solonetzic soil ; Solonetz-Solod sequence ; Triticum aestivum ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The growth and mineral composition of barley and wheat was measured across sequences of Solonetz and Solod soils. Growth of both species, along with root penetration was reduced on the Solonetz compared to the Solod soil. Mineral composition of the foliage and roots indicated that a Na−K interaction was present for the barley across the Solonetz-Solod sequences. Such factors were considered to be characteristics of soil—plant relationships on Solonetzic soils.
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  • 91
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; chromosome substitution lines ; vernalization ; ear emergence ; basic development rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The influence of vernalization on days to ear emergence in hexaploid wheat (Triticum aestivum L. em. Thell.) was examined in five Chinese Spring/Thatcher (CS/T) chromosome substitution lines. CS/T 5A and 5D were similar to normal Chinese Spring in days to ear emergence after all periods of vernalization while CS/T 3B and 5B were similar after some, but significantly earlier after other periods of vernalization When compared with Chinese Spring. In both the unvernalized condition and when vernalization did not limit development rate CS/T 7B was faster to ear emergence than Chinese Spring. These results are discussed in relation to the known chromosomal and genetical control of vernalization response.
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  • 92
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    Euphytica 32 (1983), S. 225-230 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; shattering ; awns ; height
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Temporal changes in shattering losses of 14 wheat (Triticum aestivum L.) genotypes were studied in an irrigated environment. The lines ranged in height from 68 to 98 cm; eight lines were fully awned while five were not. Shattered kernels were gathered at weekly intervals for 6 wk; samping commenced at 30 to 40% kernel moisture and continued for 3 wk beyond harvest ripeness (14.5% moisture). Shattering loss, expressed as a percentage of yield, ranged from 3.25 to 17.3% over the 6 wk period. Awnedness was not a factor in shattering susceptibility of the genotypes studied. Both the most and least shattering resistant lines in this study were awnless. There was a nonsignificant correlation between shattering losses and plant height. It was concluded that a single quantitative measurement of shattering loss at or after harvest ripeness (14.5% moisture) would provide an adequate measure of shattering susceptibility.
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  • 93
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    Euphytica 32 (1983), S. 241-255 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; physiology ; grain yield ; inheritance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Post anthesis physiological characters were examined in four genotypes and a diallel set of their progenies. Variation in total carbon uptake by photosynthetic tissue above the flag leaf node was primarily related to leaf area and ear size differences during the early grain filling period. Flag leaf apparent photosynthetic rates during the late grain filling period were closely correlated with flag leaf chorophyl levels. During the period of rapid growth, genotypes differed in the proportion and total quantity of current assimilate translocated to the grain. Total rather than proportional translocation was correlated with grain number and grain yield. Differences in total grain protein were primarily related to total plant nitrogen at anthesis and secondarily to the proportion of this nitrogen translocated to the grain. The level of post anthesis nitrate reductase activity decreased with increasing flag leaf age, but genotypic differences were not closely related to differences in total grain protein contents. Significant general combining ability effects were found for flag leaf chlorophyll levels, flag leaf photosynthetic rates at higher illuminances during the late grain filling period, total plant carbon uptake, total ear carbon uptake, and proportional carbon translocation to the grain. A preponderance of significant general combining ability variances suggests that additive gene action is of particular importance in the inheritance of these physiological characters.
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  • 94
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    Euphytica 32 (1983), S. 257-271 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; bread wheat ; Triticum durum ; durum wheat ; Triticum compactum ; collection ; germplasm ; land-races ; local varieties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Wheat has traditionally been grown by the Beduin population in the semi-arid (150 to 200 mm, mean total annual rainfall) northern Negev region of Israel. A collection was made in this area (the size of which is 150 km2) from small (0.1 to 0.5ha) fields of mixed wheat, resulting in 1553 collected spikes. Each spike was planted in a 1 m row at Bet Dagan, and grown under favorable conditions. Qualitative and quantitative data were collected from each row. Qualitative data were submitted to hierarchial clustering and the results were compared with published information on the identification, classification and distribution of the land-races of wheat in the Middle East. Triticum durum was represented in 84% of the collection. It was clustered into 22 populations, identified as 11 known varietas of T. durum. They were aggregated into five groups, similar to groups of old varieties recognized by Jacubziner (1932). While 38.5% of the collection consisted of T. durum groups villosa and sinaica, aboriginal to the northern Negev, it included also forms similar to several land-races found in the past in other parts of the Middle East. Each of the populations, and the durum collection as a whole, was very diverse for the quantitatively measured plant attributes. Triticum aestivum was represented in 15.6% of the collection, clustered into six populations. Most of the common wheat accessions were analogous to the old locally grown variety Hirbawi. Triticum compactum was represented in only eight accessions. The collection is now being evaluated as a potential genetic resource for durum wheat breeding.
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  • 95
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; bread wheat ; grains ; dry matter and nitrogen ; distribution within ear ; plant height
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Distribution and accumulation of dry matter (d.m.) and nitrogen (N) were investigated within ears of a semidwarf, a gigas, and a normal wheat genotype grown under controlled environments. A high harvest index was linked with a small pre-anthesis N-storage (and vice versa) but this did not affect N amounts in grains because of compensation by prolonged N uptake during grain filling. N distribution within and between spikelets roughly paralleled that of d.m. Nevertheless, the two processes appeared to be rather independent as became evident from comparisons of the time courses in and between the genotypes. Final distribution of d.m. and N within and between spikelets mainly depended on different rates during the linear phases of accumulation and less on the duration. Maximum of d.m. and N weights per grain as well as maximum of grain number were observed in spikelets below the middle of the ear axis. This ‘submedian dominance’ suggested a pre-anthesis determination of the accumulation potential of grains in different spikelets. N percentage within spikelets disclosed that N accumulation was hampered more than that of d.m. in those positions unfavourable to the latter process. This principal pattern was not affected by genotypes in spite of considerable differences in numbers and weights of grains.
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  • 96
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    Euphytica 32 (1983), S. 575-584 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat seedlings ; Triticum sp. ; Septoria nodorum ; glume blotch disease ; components of partial resistance ; multivariate analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Components of partial resistance of wheat seedlings to Septoria nodorum were measured in a glasshouse. Incubation period, infection frequency, latent period, lesion size, lesion cover, necrosis and unit spore production were recorded on 41 Triticum genotypes. There was no clear evidence of associated variation in components and multivariate analyses were used to elucidate such relationships. Factor analysis indicated that pathogen-induced necrosis, related possiby to toxin susceptibility, and unit spore production were major components of partial resistance to S. nodorum. Principal component analysis was used to characterise genotypes: associated with a continuous general resistance could be a high level of pathogen-induced necrosis or a high unit spore production, but rarely both in the same genotype.
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  • 97
    Electronic Resource
    Electronic Resource
    Springer
    Hydrobiologia 98 (1983), S. 223-235 
    ISSN: 1573-5117
    Keywords: diatoms ; paleolimnology ; lakes ; Minnesota ; sediments ; microfossils
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fossil diatom assemblages from the sediment/water interface in 105 Minnesota lakes were compared with measurements of alkalinity, sulphate, total phosphorus, transparency, and water depth at the sample site. Similar assemblages were placed together using cluster analysis and comparisons of environmental variables between diatom clusters were made using an analysis of variance. Total alkalinity and transparency showed the greatest difference among clusters. Samples from shallow eutrophic prairie lakes were dominated by Melosira granulata, Stephanodiscus niagarae and, occasionally, by Stephanodiscus hantzschii. Deep oligotrophic lakes had modest percentages of Cyclotella comta. Dilute acid lakes were dominated either by Melosira distans and M. italica or by Tabellaria fenestrata, Cyclotella stelligera, and in some cases C. glomerata. Assemblages with Cyclotella glomerata and Synedra nana were found in naturally meromictic lakes. Stephanodiscus hantzschii showed a preference for extremely eutrophic lakes. The relationships between recently deposited diatom assemblages and the lake environmental conditions studied here can be used to evaluate the extent of past environmental change in lakes.
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  • 98
    ISSN: 1573-5117
    Keywords: Chrysophycea ; cultural eutrophication ; paleolimnology ; resting cyst ; statospore ; stratigraphy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The recent sediments of Frains Lake, Michigan contain a rich and well preserved association of chrysophycean cysts. Forty one forms are revealed by scanning electron microscopy (SEM) and light microscopy (LM). Taxonomic descriptions. and SEM micrographs are provided for the dominant forms. The three dominant taxa throughout the sediments, Cysta minima, C. modica and C. subbavaricum, do not show significant shifts in proportional abundance associated with European settlement and the onset of cultural eutrophication. However, certain subdominant taxa do show clear trends. Density counts indicate a dramatic decline in cyst concentration (by volume and by dry mass) and a sharp increase in absolute accumulation (net annual influx) following settlement. The Frains Lake profile of chrysophycean cysts is compared to sequences of other North American and European temperate lakes. The utility of chrysophycean cysts as paleoenvironmental indicators is considered on the basis of these results.
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  • 99
    Electronic Resource
    Electronic Resource
    Springer
    Hydrobiologia 103 (1983), S. 125-130 
    ISSN: 1573-5117
    Keywords: paleolimnology ; pollen ; diatoms ; Synuraceae ; Chrysophyta ; meromixis ; eutrophication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The recent history of Little Round Lake, a small meromictic lake in southeastern Ontario, is considered. Pollen analyses were used to identify past changes in terrestrial vegetation, whilst limnological conditions were interpreted on the basis of diatom and chrysophyte microfossils. Contemporaneous with the arrival of European settlers (ca. A. D. 1850), the predisturbance assemblage of oligotrophic Cyclotella diatoms was replaced by Synedra spp., which then succeeded to a eutrophic flora dominated by Stephanodiscus hantzschii. Meanwhile, synuracean algae were almost completely excluded. Over the last 30 years, the algal microfossils indicate that the lake underwent a marked return to oligotrophy. Evidence is presented which suggests that this shift was related to the cultural enhancement of meromixis by the seepage of road salt.
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  • 100
    ISSN: 1573-5117
    Keywords: paleolimnology ; acidic precipitation ; lake acidification ; heavy metal pollution ; diatoms ; cladocerans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sediment cores from nine lakes in southern Norway (N) and six in northern New England (NE) were dated by 137Cs, 210Pb and in NE also by pollen, and were analyzed geochemically and for diatoms. Cores from two N and three NE lakes were analyzed for cladocerans. 137Cs dating is unreliable in these lakes, probably due to mobility of Cs in the sediment. In Holmvatn sediment, an up-core increase in Fe, starting ca. 1900, correlates with geochemical indications of decreasing mechanical erosion of soils. Diatoms indicate a lake acidification starting in the 1920's. We propose that soil Fe was mobilized and runoff acidified by acidic precipitation and/or by soil acidification resulting from vegetational succession following reduced grazing. Even minor land use changes or disturbances in lake watersheds introduce ambiguity to the sedimentary evidence relating to atmospheric influences. Diatom counts from surface sediments in 36 N and 31 NE lakes were regressed against contemporary water pH to obtain coefficients for computing past pH from subsurface counts. Computed decreases of 0.3–0.8 pH units start between I890 and I930 in N lakes already acidic (pH 5.0–5.5) before the decrease. These and lesser decreases in other lakes start decades to over a century after the first sedimentary indications of atmospheric heavy metal pollution. It is proposed that the acidification of precipitation accompanied the metal pollution. The delays in lake acidification may be due to buffering by the lakes and watersheds. The magnitude of acidification and heavy metal loading of the lakes parallels air pollution gradients. Shift in cladoceran remains are contemporary with acidification, preceding elimination of fishes.
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