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  • Triticum aestivum  (229)
  • Inversion
  • Rat
  • Springer  (288)
  • 3
  • Wiley
  • 1995-1999  (288)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Animal cognition 2 (1999), S. 123-129 
    ISSN: 1435-9456
    Keywords: Key words Face recognition ; Inversion ; Expertise ¶effect ; Matching-to-sample ;  Macaca mulatta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This study investigated the face inversion effect in rhesus monkeys (Macaca mulatta). Face stimuli consisted of ten black-and-white examples of unfamiliar rhesus monkey faces, brown capuchin faces, and human faces. Two non-face categories included ten examples of automobiles and abstract shapes. All stimuli were presented in a sequential matching-to-sample format using an automated joystick-testing paradigm. Subjects performed significantly better on upright than on inverted presentations of automobiles, rhesus monkey and capuchin faces, but not human faces or abstract shapes. These results are inconsistent with data from humans and chimpanzees that show the inversion effect only for categories of stimuli for which subjects have developed expertise. The inversion effect in rhesus monkeys does not appear to be face-specific, and should therefore not be used as a marker of specialized face processing in this species.
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  • 2
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    Entomologia experimentalis et applicata 91 (1999), S. 403-412 
    ISSN: 1570-7458
    Keywords: aphid ; Diuraphis noxia ; Triticum aestivum ; endosymbiont ; insect-plant interactions ; phloem ; amino acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The feeding behavior of Diuraphis noxia Mordvilko (Homoptera: Aphididae) on susceptible hosts causes both ultrastructural and tissue level damage which may affect phloem composition. Genetic evidence suggests that endosymbiotic bacteria in most aphids overproduce limiting amino acids to benefit hosts but that D. noxia depends less on endosymbionts for these nutrients, possibly due to an enriched diet. To determine whether D. noxia feeding damage results in higher concentrations of essential amino acids, stylet exudates were analyzed from wheat (Triticum aestivum) damaged to different degrees. Comparison of samples from undamaged and damaged susceptible wheat revealed changes in amino acid composition and an increase in levels of essential amino acids, indicating a nutritionally enhanced ingesta. The changes in stylet exudates paralleled changes in leaf exudates, indicating that the effects are systemic. Feeding damage is not observed on a resistant wheat host, var. Halt, and leaf exudates from infested Halt did not show changes in amino acid composition. Mean relative growth of nymphs was significantly lower on Halt than on susceptible Arapahoe, indicating that Halt is a less suitable host. Both varieties show similar amino acid levels in non-infested samples, suggesting that D. noxia infestation does not enhance the phloem environment in Halt. This study provides evidence that aphid feeding can generate a nutritionally enhanced phloem diet.
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  • 3
    ISSN: 1570-7458
    Keywords: sieve element ; salivation ; aphid ; plant resistance ; wheat ; Sitobion fragariae ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Extended sieve element salivation (E1 waveform in the electrical penetration graph) is a characteristic activity during early sieve element punctures, particularly in resistant plants. In order to explore a chemically-mediated mechanism of resistance associated with sieve element salivation, we compared the pattern of feeding behaviour of the aphid, Sitobion fragariae (Walker), on two cultivars of the wheat Triticum aestivum L., with different concentrations of hydroxamic acids (Hx). During 24 h of electronic monitoring, aphids dedicated over 50% of the total time to phloem ingestion from the sieve elements. Total time allocated to E1 in the experiment, time to first E1 within the experiment, time allocated to E1 before a sustained phloem ingestion (E2) and the contribution of sieve element salivation to the phloem phase (E1/[E1+E2]) were significantly higher in the high-Hx cultivar. The increased salivation in plants with higher contents of Hx suggests the existence, at least in this system, of a chemically-mediated sieve element constraint.
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  • 4
    ISSN: 1432-1890
    Keywords: Key words Glomus mosseae ; Hydroponics ; Nitrate uptake ; Root respiration ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Oxygen and CO2 fluxes were measured in hydroponically grown mycorrhizal and non-mycorrhizal Triticum aestivum L. cv. Hano roots. The NO3 – uptake of the plants was used to estimate the amount of root respiration attributable to ion uptake. Plants were grown at 4 mM N and 10 μM P, where a total and viable mycorrhizal root colonisation of 48% and 18%, respectively, by Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe (BEG 107) was observed. The O2 consumption and NO3 – uptake rates were similar and the CO2 release was higher in mycorrhizal than in non-mycorrhizal wheat. This resulted in a significantly higher respiratory quotient (RQ, mol CO2 mol–1 O2) in mycorrhizal (1.27±0.13) than in non-mycorrhizal (0.79±0.05) wheat. As the biomass and N and P concentrations in mycorrhizal and non-mycorrhizal wheat were the same, the higher RQ resulted from the mycorrhizal colonisation and not differences in nutrition per se.
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  • 5
    ISSN: 1432-0789
    Keywords: Key words Phosphate-solubilizing microorganisms ; Mussoorie rock phosphate ; Vesicular-arbuscular mycorrhizae ; Triticum aestivum ; Nutrient-deficient soils
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  The effect of inoculating wheat (Triticum aestivum L.) with the PO4 3–-solubilizing microorganisms (PSM) Bacillus circulans and Cladosporium herbarum and the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus sp. 88 with or without Mussoorie rock phosphate (MRP) amendment in a nutrient-deficient natural sandy soil was studied. In the sandy soil of low fertility root colonization by VAM fungi was low. Inoculation with Glomus sp. 88 improved root colonization. At maturity, grain and straw yields as well as N and P uptake improved significantly following inoculation with PSM or the VAM fungus. These increases were higher on combined inoculation of PSM and the VAM fungus with MRP amendment. In general, a larger population of PSM was maintained in the rhizosphere of wheat in treatments with VAM fungal inoculation and MRP amendment. The results suggest that combined inoculation with PSM and a VAM fungus along with MRP amendment can improve crop yields in nutrient-deficient soils.
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  • 6
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    Nutrient cycling in agroecosystems 53 (1999), S. 157-175 
    ISSN: 1573-0867
    Keywords: Brassica napus ; Cicer arietinum ; current P ; Lens culinaris ; Lupinus albus ; Lupinus angustifolius ; P concentration response ; P content response ; Pisum sativum ; previous P ; sigmoid response ; single superphosphate ; Triticum aestivum ; Vicia faba ; yield response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Phosphorus (P) is a major deficiency of soils of south-western Australia (WA). The fertilizer P requirements are not known for grain legumes being evaluated for neutral to alkaline, fine textured soils in WA. To rectify this, glasshouse and field experiments were undertaken to compare the responses of several grain legume species, wheat and canola to applications of single superphosphate and the results are reported in this paper. The glasshouse experiments measured responses of dried tops, harvested at 26 to 42 days after sowing, to P that was freshly-applied (current P) and previously-applied (previous P). Responses in the glasshouse were measured using yield, P concentration and P content (P concentration multiplied by yield) of oven dried tops of the following: wheat (Triticum aestivum), canola (Brassica napus), faba bean (Vicia faba), chickpea (Cicer arietinum), lentil (Lens culinaris), field pea (Pisum sativum), albus lupin (Lupinus albus) and narrow leaf lupin (Lupinus angustifolius). Field experiments in 1994 and 1995 compared seed (grain) yield responses of faba bean, chickpea, lentil, albus lupin and wheat to applications of current P. The P was banded (drilled) with the seed while sowing at 5 cm depth. Canola and wheat produced very large yield responses to increasing applications of current P. Responses were much smaller for albus lupin, faba bean and chickpea. Responses for lentil, narrow leaf lupin and field pea, fell in between responses of the small and large seeded species. Similar trends for responses were obtained as measured using yield, P concentration, or P content. For soils treated with previous P, similar trends were observed as for current P, but differences in yield responses between species were much less marked and the response curves tended to become more sigmoid. In the field experiments, grain yield responses to current P of albus lupin and chickpea were less than that for wheat. Relative to wheat, faba bean was the most responsive grain legume to applications of current P, with lentil producing similar responses to wheat in one experiment at a newly cleared, P deficient site.
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  • 7
    ISSN: 1432-1211
    Keywords: Key words Class II MHC sequence ; Rat ; Cloning ; RT-PCR ; Polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
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  • 8
    ISSN: 1432-1890
    Keywords: Key words Arbuscular mycorrhiza ; Hordeum vulgare ; Triticum aestivum ; Glomus intraradices ; Mycorrhiza-helper bacteria ; Secondary compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Colonization of Hordeum vulgare L. cv. Salome (barley)and Triticum aestivum L. cv. Caprimus (wheat) roots by the arbuscular mycorrhizal fungus Glomus intraradices Schenck & Smith leads to de novo synthesis of isoprenoid cyclohexenone derivatives with blumenin [9-O-(2′-O-β-glucuronosyl)-β-glucopyranoside of 6-(3-hydroxybutyl)-1,1,5-trimethyl-4-cyclohexen-3-one] as the major constituent and to transient accumulation of hydroxycinnamate amides (4-coumaroylagmatine and -putrescine). Accumulation of these compounds in mycorrhizal wheat roots started 2 weeks after sowing together with the onset of arbuscule formation and proceeded with mycorrhizal progression. Highest levels were reached in 3- to 4-week-old secondary roots (root branches of first and higher order) characterized by the formation of vesicles. In the final developmental stages, the fungus produced massive amounts of spores, enclosing the stele of older root parts (older than 5 weeks) characterized by cortical death. In these root parts, the secondary compounds were detected in trace amounts only, indicating that they were located in the cortical tissues. Some rhizosphere bacteria tested, i.e. Agrobacterium rhizogenes, Pseudomonas fluorescens, and Rhizobium leguminosarum, markedly stimulated both fungal root colonization and blumenin accumulation, thus, acting as mycorrhiza-helper bacteria (MHB). Application of blumenin itself strongly inhibited fungal colonization and arbuscule formation at early stages of mycorrhiza development. This was associated with a markedly reduced accumulation of the hydroxycinnamate amides 4-coumaroylputrescine and -agmatine. The results suggest that both the isoprenoid and the phenylpropanoid metabolism are closely linked to the developmental stage and the extent of fungal colonization. Their possible involvement in the regulation of mycorrhiza development is discussed.
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  • 9
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    Theoretical and applied genetics 98 (1999), S. 472-477 
    ISSN: 1432-2242
    Keywords: Key words QTL ; Ear emergence time ; Plant height ; Recombinant substitution line ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Chromosome 5A of wheat carries major gene loci for agronomic traits including the vernalization requirement (Vrn-A1) and ear morphology (Q). To determine whether the genetic variation for ear emergence time and plant height is attributable to either of these major genes as pleiotropic effects or independent QTL, we combined a RFLP map constructed from 120 recombinant substitution lines derived from a cross between ‘Chinese Spring’ (Cappelle-Desprez 5A) and CS(Triticum spelta 5A) with data collected from field trials over 3 years. For ear emergence time the main effects on flowering time were by Vrn-A1 and QEet.ocs-5A.1, the latter a QTL in the 28.6-cM Xcdo584/Q interval linked to Q by less than 10 cM. The CS(T. spelta 5A) allele at QEet.ocs-5A.1 contributed to an earlier ear emergence time by 2.7–6.0 days, which was approximately equal to the effects of Vrn-A1. For plant height, three QTLs were identified on the long arm and linked in repulsion. The CS(T. spelta 5A) allele at Vrn-A1 or closely linked to Xfba068 contributed to a height reduction of 3.5–6.1 cm, whereas both the Q allele and Qt.ocs-5A.1 allele within the Xcdo1088/Xbcd9 interval from CS(Cappelle-Desprez 5A) produced a shorter plant. When plant height was partitioned into culm length and ear length, the Vrn-A1 allele and CS(Cappelle-Desprez 5A) allele at QCl.ocs-5A.1 within the Xcd1088/Xbcd9 interval were found to contribute to a shorter culm. CS(T. spelta 5A) allele at q was a major determinant of a long ear, together with minor effects at QEl.ocs-5A.1 within the Xcdo1088/Xbcd9 interval.
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  • 10
    ISSN: 1432-2242
    Keywords: Key words Erysiphe graminis ; Powdery mildew resistance ; QTL ; Triticum aestivum ; Triticum spelta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Powdery mildew is one of the major diseases of wheat in regions with a maritime or semi-continental climate and can strongly affect grain yield. The attempt to control powdery mildew with major resistance genes (Pm genes) has not provided a durable resistance. Breeding for quantitative resistance to powdery mildew is more promising, but is difficult to select on a phenotypic basis. In this study, we mapped and characterised quantitative trait loci (QTLs) for adult-plant powdery mildew resistance in a segregating population of 226 recombinant inbred lines derived from the cross of the Swiss wheat variety Forno with the Swiss spelt variety Oberkulmer. Forno possibly contains the Pm5 gene and showed good adult-plant resistance in the field. Oberkulmer does not have any known Pm gene and showed a moderate susceptible reaction. Powdery mildew resistance was assessed in field trials at two locations in 1995 and at three locations in 1996. The high heritability (h2=0.97) for powdery mildew resistance suggests that the environmental influence did not affect the resistance phenotype to a great extent. QTL analysis was based on a genetic map containing 182 loci with 23 linkage groups (2469 cM). With the method of composite interval mapping 18 QTLs for powdery mildew resistance were detected, explaining 77% of the phenotypic variance in a simultaneous fit. Two QTLs with major effects were consistent over all five environments. One of them corresponds to the Pm5 locus derived from Forno on chromosome 7B. The other QTL on 5A, was derived from the spelt variety Oberkulmer and did not correspond to any known Pm gene. In addition, five QTLs were consistent over three environments, and six QTLs over two environments. The QTL at the Pm5 locus showed a large effect, although virulent races for Pm5 were present in the mixture of isolates. Molecular markers linked with QTLs for adult-plant resistance offer the possibility of simultaneous marker-assisted selection for major and minor genes.
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  • 11
    ISSN: 1432-2242
    Keywords: Key words Aegilops tauschii ; Triticum aestivum ; Genetic mapping ; Molecular markers ; Agronomically important genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Aegilops tauschii is the diploid D-genome progenitor of bread wheat (Triticum aestivum L. em Thell, 2n=6x=42, AABBDD). A genetic linkage map of the Ae. tauschii genome was constructed, composed of 546 loci. One hundred and thirty two loci (24%) gave distorted segregation ratios. Sixty nine probes (13%) detected multiple copies in the genome. One hundred and twenty three of the 157 markers shared between the Ae. tauschii genetic and T. aestivum physical maps were colinear. The discrepancy in the order of five markers on the Ae. tauschii 3DS genetic map versus the T. aestivum 3D physical map indicated a possible inversion. Further work is needed to verify the discrepancies in the order of markers on the 4D, 5D and 7D Ae. tauschii genetic maps versus the physical and genetic maps of T. aestivum. Using common markers, 164 agronomically important genes were assigned to specific regions on Ae. tauschii linkage, and T. aestivum physical, maps. This information may be useful for map-based cloning and marker-assisted plant breeding.
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  • 12
    ISSN: 1432-2242
    Keywords: Key words Lodging ; Morphological traits ; QTL ; Triticum aestivum ; Triticum spelta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Lodging can strongly affect both the grain yield and the quality of wheat. Lodging represents a quantitative trait and is difficult to assess on a phenotypic basis. Marker-assisted selection (MAS) could therefore become an important tool in breeding for lodging resistance. In this study, we mapped and characterised quantitative trait loci (QTLs) for lodging resistance, as well as morphological traits correlated with lodging, in a segregating population of 226 recombinant inbred lines derived from the cross of the lodging-resistant wheat variety Forno with the susceptible spelt variety Oberkulmer. Lodging, plant height, leaf width, leaf-growth habit, culm stiffness, culm swinging, culm thickness, days to ear emergence and days to flowering were assessed in field trials at two locations in 1996 and at one location in 1997. Additionally, at one location weight and length parameters were also assessed. Plant height and culm stiffness explained 77% of the phenotypic variance of lodging in a multiple regression model over all three environments. QTL analysis of lodging and morphological parameters was based on a genetic map containing 230 loci with 23 linkage groups (2469 cM). With the method of composite interval mapping nine QTLs for lodging resistance were detected, explaining 63% of the phenotypic variance in a simultaneous fit. Seven of these QTLs coincided with QTLs for morphological traits, reflecting the correlations between these traits and lodging. In our population the most efficient way to improve lodging resistance would be by a combination of indirect selection on plant height and culm stiffness together with MAS on the two QTLs for lodging resistance which did not coincide with QTLs for morphological traits.
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  • 13
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    Theoretical and applied genetics 98 (1999), S. 1248-1252 
    ISSN: 1432-2242
    Keywords: Key words Wheat ; Chromosome sorting ; Chromosome isolation ; Aneuploids ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We are reporting the successful isolation of wheat chromosome arm 1DS by flow cytometry. A chromosome suspension was prepared for the 1DS ditelosomic line and the normal ‘Chinese Spring’ (CS) by chopping 2-day-old root tip meristems, synchronized by hydroxyurea, in HEPES-magnesium sulfate buffer containing propidium iodide. Chromosomes were analyzed and sorted with a FACS Vantage flow cytometer and cell sorter. An extra peak was observed in the flow karyotype of the ditelosomic line that was absent in ‘CS’. The estimated size of chromosomes from the extra peak matched with the expected size of chromosome 1DS. Chromosomes from the putative 1DS peak were analyzed by both fluorescent microscopy and N-banding analysis. A total of 571 chromosomes from two separate experiments were analyzed, and all were observed to be telosomics except for 2 which were broken. About 82% of these telosomics showed the diagnostic N-band of 1DS, the remaining were unbanded and are probably also 1DS. This strategy can also be used to sort other wheat arms.
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  • 14
    ISSN: 1432-2242
    Keywords: Key words Transgenic wheat ; Triticum aestivum ; Tritordeum ; Transgene inheritance ; Marker gene stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The stability and heritability of three marker genes was investigated in a population of twelve independent transgenic cereal lines (six wheat and six tritordeum). Integration patterns, inheritance of structural transgenes and inheritance of expression were analysed in the T0 and T1 generations for all 12 lines. Transmission and expression were analysed in the T2 generation for 9 lines and in the T3 generation for the six wheat lines. Inheritance of integration patterns was highly stable, and transmission of the transgenes and inheritance of their expression followed Mendelian ratios in the majority of lines. A gradual reduction in uidA expression was observed over three generations, which was not accompanied by a similar reduction in bar expression. Some unexpected phenomena associated with transgene inheritance were also observed and are discussed.
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  • 15
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    Cell & tissue research 296 (1999), S. 235-246 
    ISSN: 1432-0878
    Keywords: Key words Transplantation ; Parkinson’s disease ; CNS fetal development ; CNS differentiation ; Neurotrophic factors ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We have previously shown that a combination of the cytokines interleukin (IL)-1, IL-11, leukemia inhibitory factor (LIF), and glial cell line-derived neurotrophic factor (GDNF) can convert rat fetal (E14.5) mesencephalic progenitor cells into tyrosine hydroxylase (TH)-immunoreactive (ir) neurons in vitro. The experiments described here characterize the mesencephalic progenitor cells and their cytokine-induced conversion into dopamine (DA) neurons. For all experiments, we used bromodeoxyuridine (BrdU)-ir cultures of (E14.5) mesencephalic progenitor cells that had been expanded at least 21 days. We first demonstrated that IL-1 induced DA neuron conversion in mesencephalic progenitors, but not in striatal progenitors (P〈0.001). Thus, these cells should be classified as lineage-restricted progenitors, and not omnipotent stem cells. To further characterize cell populations in these cultures, we used monoclonal antibodies against Hu (an early marker for neurons), growth-associated protein (GAP)-43 (a marker for neuronal process extension), TH (a marker for DA neurons), and glial fibrillary acidic protein (GFAP, a marker for astrocytes). We assessed (E14.5) mesencephalic progenitor cell cultures (plated at 125,000 cells/cm2) incubated in the cytokine mixture (described above) or in complete media (CM, negative control). Following 7 days incubation, GFAP-positive cells formed a nearly confluent carpet in both types of cultures. However, numbers of Hu-ir and GAP-43-ir cells in the cytokine-incubated cultures far exceeded those in CM-incubated controls (P=0.0003, P=0.0001, respectively), while numbers of TH-ir cells were 58-fold greater in the cytokine-incubated cultures versus CM-incubated controls. The TH phenotype persisted for 7 days following withdrawal of the differentiation media. Numerous double-labeled cells that were BrdU-ir and also TH-ir, or Hu-ir and also TH-ir, were observed in the cytokine-incubated cultures. These data suggest that cytokines ”drive” the conversion of progenitor cells into DA neurons.
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  • 16
    ISSN: 1432-0878
    Keywords: Key words Subcommissural organ ; Isograft ; Xenograft ; Reissner’s fiber ; Cerebrospinal fluid ; Rat ; Bovine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The subcommissural organ (SCO) secretes glycoproteins into the cerebrospinal fluid (CSF) that aggregate and form Reissner’s fiber (RF). The factors involved in this aggregation are not known. One factor may be the hydrodynamics of the CSF when flowing through the aqueduct. This hypothesis was tested by isografting rat SCO and xenografting bovine SCO into the lateral ventricle of rats. Xenografts were either fresh bovine SCO or explants cultured for 30 days before transplantation. The grafts were investigated by electron microscopy and immunocytochemistry using antibodies against RF glycoproteins, serotonin and the glucose transporter I. Maximal time of transplantation was 43 days for isografts and 14 days for xenografts. The isografts were not reinnervated but were revascularized; they secreted into the ventricle RF glycoproteins that became progressively packed into pre-RF and RF structures identical to those formed by the SCO in situ. RF was confined to the host ventricle and at its distal end the constituent proteins disassembled. Xenografts were neither reinnervated nor revascularized and secreted into the host ventricle a material that never formed an RF. These findings indicate that the CSF factor responsible for the formation of RF is species specific, and that this process does not depend on the hydrodynamics of the CSF. The blood vessels revascularizing the isografted SCO acquired the characteristics of the vessels irrigating the SCO in situ, namely, a tight endothelium displaying glucose transporter I, and a perivascular space containing long-spacing collagen, thus indicating that basal release of glycoproteins may also occur in the grafted SCO.
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  • 17
    ISSN: 1432-0878
    Keywords: Key words Axonal transport ; Purkinje cell ; Organotypic culture ; Microinjection ; Antimitotic drugs ; Cytoskeleton ; Dendritic transport ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Axonal and dendritic transport in single Purkinje neurons of cerebellar slice cultures was quantified as single transport distances. Examination of the cells within a vital tissue was regarded as being an approach to the in situ condition. The Purkinje cells were organotypically integrated in the in vitro tissues and extended long axonal projections connecting synapses to the target neurons. The tracer horseradish peroxidase (HRP) was applied via microinjection to the somata of the Purkinje cells and the injected neurons were incubated thereafter for defined time-intervals. The tracer was transported anterogradely into the neuron processes. The measurements on both the axonal and the dendritic transport of microinjected HRP revealed continuous transportation with increasing times of postincubation. This transport was reduced by the use of microtubule-depolymerizing drugs. The axonal transport of the tracer was either retarded in colchicine-treated cells or continuously reduced for up to 50% in vinblastine-treated neurons. Thus, a correlation of axonal transport to the microtubules was demonstrated. The dendrites were filled with the tracer after 60 min of postincubation. Dendritic transport was reduced by the use of vinblastine, and not significantly by colchicine. The results strongly support the dependence of neuronal transport on microtubules as a component of the cytoskeleton.
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  • 18
    ISSN: 1432-0878
    Keywords: Key words Neurofilament ; Basket cell ; Pinceau ; Golgi apparatus ; Calcium binding protein ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract NCS-1 (neuronal calcium sensor) is a recently characterized member of a highly conserved neuron-specific family of calcium-binding proteins, which also includes frequenin and recoverin. The cellular and subcellular distributions of NCS-1 in the rat nervous system were investigated using light- and electron-microscopic immunohistochemistry. NCS-1 immunoreactivity was localized to neuronal cell bodies and axons throughout the brain and spinal cord but not to glial cells. The most intense labeling was observed in myelinated axons, the axonal ramifications of the basket cell in the cerebellar cortex, and large neurons in the brainstem and pons. These same structures were also characterized by heavy labeling for neurofilament protein, as determined by double-labeling experiments. Most axon terminals were unlabeled or only lightly labeled. The most remarkable subcellular staining occurred in the perikarya where intense labeling was associated with the membranes of the trans saccules of the Golgi apparatus. The widespread distribution of NCS-1 indicates that it may be active in a variety of calcium-dependent neuronal functions, whereas the specific subcellular localization to the Golgi apparatus and neurofilament-rich structures suggests a specialized role in calcium regulated protein trafficking and cytoskeletal interactions.
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  • 19
    ISSN: 1432-0878
    Keywords: Key words Glial cell line-derived neurotrophic factor ; GDNF ; Ret ; GDNFR-α ; Brain-derived neurotrophic factor ; BDNF ; NT-3 ; NT-4 ; trk receptors ; Thyroid tissue ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Levels of mRNA for neurotrophins (brain-derived neurotrophic factor, BDNF; neurotrophin 3, NT-3; neurotrophin 4, NT-4) and their receptors (trkA, trkB, trkC) and for glial cell line-derived neurotrophic factor (GDNF) and its receptors (ret, GDNFR-α) were measured in rat thyroid tissue by ribonuclease protection assays. In thyroid tissue the NT-3 mRNA level was threefold lower and the NT-4 mRNA level sixfold higher than those detected in adult rat hippocampus, while BDNF mRNA was undetectable. Very low levels of mRNA for truncated trkB and trkC receptors and no catalytic trkA, trkB or trkC were found. In conclusion NT-3 and NT-4, but not the corresponding functional receptors, are expressed in the thyroid tissue. Therefore, it is unlikely that these factors serve a direct local autocrine or paracrine function in thyroid cell types, and a target-derived mode of action on neurons innervating the thyroid tissue is suggested. An opposite result has been found for the neurotrophic factor GDNF: thyroid tissue showed a high level of transcripts for the GDNF receptor subunits (GDNFR-α and Ret), while GDNF mRNA was undetectable. The in situ hybridization analysis of GDNFR-α and ret mRNA revealed an interesting difference in the cell distribution of these transcripts: ret mRNA is selectively expressed in a subpopulation of cells scattered in the follicular epithelium and in the interfollicular spaces, while GDNFR-α expression is more homogeneous and widespread, including the more abundant cell type of the thyroid gland: the follicular cell. Double-labeling in situ hybridization/immunocytochemistry experiments, with a specific marker (calcitonin), showed that parafollicular cells express ret but not GDNFR-α. This differential distribution of the GDNF receptor components (GDNFR-α and ret) may reflect a peculiar biological role in intercellular communication in the thyroid gland.
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  • 20
    ISSN: 1432-0878
    Keywords: Key words Water channel protein ; Aquaporin ; AQP5 ; Rat ; Salivary glands ; Immunolocalization ; Secretory stimulation ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Aquaporin-5 (AQP5) is a water channel protein and is considered to play an important role in water movement across the plasma membrane. We raised anti-AQP5 antibody and examined the localization of AQP5 protein in rat salivary and lacrimal glands by immunofluorescence microscopy. AQP5 was found in secretory acinar cells of submandibular, parotid, and sublingual glands, where it was restricted to apical membranes including intercellular secretory canaliculi. In the submandibular gland, abundant AQP5 was also found additionally at the apical membrane of intercalated duct cells. Upon stimulation by isoproterenol, apical staining for AQP5 in parotid acinar cells tended to appear as clusters of dots. These results suggest that AQP5 is one of the candidate molecules responsible for the water movement in the salivary glands.
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  • 21
    ISSN: 1573-9368
    Keywords: low molecular weight glutenin promoter ; particle bombardment ; transgene expression ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transgenic wheat plants from specific cultivars can now be routinely engineered in many laboratories. However, our understanding of the factors controlling transgene expression and stability in wheat compared to other cereals is rather limited. Only a few promoters have been tested in transgenic wheat, and relatively little is known of their relative activities and expression parameters. In the present study, the spatial and temporal properties of one heterologous constitutive promoter and one seed‐specific wheat promoter were investigated. We generated constructs with the reporter gene gusA (β‐glucuronidase) driven by: (a) the constitutive maize ubiquitin‐1 (ubi‐1) promoter, and (b) two different‐sized fragments of the seed‐specific low molecular weight glutenin (LMWG1D1) promoter from wheat. The activities of all three promoter constructs were comparable in endosperm tissue. A detailed analysis of spatial and temporal properties of the promoters is described. Heat shock treatment of transgenic plants carrying the ubi‐1: gusA construct resulted in a significant elevation in the levels of GUS activity. The inheritance of transgene expression levels and stability was evaluated over four generations, as a function of transgene integration patterns and copy number.
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  • 22
    ISSN: 1618-2545
    Keywords: BLB light ; conidiogenesis ; Fusarium globosum ; subtropical Japan ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The second report ofFusarium globosum is based on strains isolated from wheat in Ishigaki Island, Okinawa, in subtropical Japan. Morphological features of the Japanese isolates are described. These strains show different reactions in conidiogenesis to light conditions. Under continuous BLB light, falcate sporodochial conidia are typically induced, but production of aerial globose conidia is suppressed. In two of the strains, clavate conidia became longer under BLB light. Application of both, complete darkness and continuous BLB light, is recommended as standard light conditions to cultureFusarium isolates.
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  • 23
    ISSN: 1573-9104
    Keywords: Bioavailability ; Magnesium ; Hijiki ; Sodium alginate ; Rat ; Wakame
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The bioavailability of magnesium from Wakame and Hijiki, and the effects of alginic acid on absorption of dietary magnesium were examined in five groups of rats fed either control, Wakame, Hijiki, AW (containing the same amount of alginate as in the Wakame) and AH (containing the same amount of alginate as in the Hijiki) diets, and animals fed a low magnesium diet (LMg) (twentieth amount of magnesium in the original mineral mixtures as the control). Food intake and body weight gain were decreased by adding sodium alginate to the diets. A large amount of calcium accumulated only in the kidneys of the rats fed the LMg diet. Serum magnesium concentration decreased only in the LMg group. The magnesium content in the defatted left femurs did not differ between the control and Wakame fed animals and also among the animals eating Wakame, Hijiki and AW diets. The breaking force of the right femurs did not differ among all the groups except the LMg group. The ratio of apparent magnesium absorption (%) of the control, LMg, Wakame, Hijiki, AW and AH groups was 82.2, 72.7, 66.9, 50.8, 69.3 and 54.2 in the first experimental period, and was 75.3, 52.1, 57.7, 46.9, 62.6 and 60.5 in the second experimental period, respectively. It was clear that the bioavailability of magnesium in the Wakame fed rats was higher than in those eating the Hijiki. Large amounts of sodium alginate lowered magnesium absorption from the diet.
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  • 24
    ISSN: 1573-5036
    Keywords: genotypic variation ; Secale cereale ; Triticum aestivum ; Triticum durum ; zinc efficiency ; zinc deficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Effect of zinc (Zn) nutritional status on uptake of inorganic 65Zn was studied in rye (Secale cereale, cv. Aslim), three bread wheat (Triticum aestivum, cvs. Dagdas, Bezostaja, BDME-10) and durum wheat (Triticum durum, cv. Kunduru-1149) cultivars grown for 13 days in nutrient solution under controlled environmental conditions. The cultivars were selected based on their response to Zn deficiency and to Zn fertilization in calcareous soils under field conditions. When grown in Zn-deficient calcareous soil in the field, the rye cultivar had the highest, and the durum wheat the lowest Zn efficiency. Among the bread wheats, BDME-10 showed higher susceptibility to Zn deficiency and Bezostaja and Dagdas were less affected by Zn deficiency. Similarly to field conditions, in nutrient solution visual Zn deficiency symptoms (i.e. necrotic lesions on leaf blade) appeared to be more severe in Kunduru-1149 and BDME-10 and less severe in rye cultivar Aslim. Under Zn deficiency, shoot concentrations of Zn were similar between all cultivars. Cultivars with adequate Zn supply did not differ in uptake and root-to-shoot translocation rate of 65Zn, but under Zn deficiency there were distinct differences; rye showed the highest rate of Zn uptake and the durum wheat the lowest. In the case of bread wheat cultivars, 65Zn uptake rate was about the same and not related to their differential Zn efficiency. Under Zn deficiency, rye had the highest rate of root-to-shoot translocation of 65Zn, while all bread and durum wheat cultivars were similar in their capacity to translocate 65Zn from roots to shoots. When Zn2+ activity in uptake solution ranged between 117 p M and 34550 pM, Zn-efficient and Zn-inefficient bread wheat genotypes were again similar in uptake and root-to-shoot translocation rate of 65Zn. The results indicate that high Zn efficiency of rye can be attributed to its greater Zn uptake capacity from soils. The inability of the durum wheat cultivar Kunduru-1149 to have a high Zn uptake capacity seems to be an important reason for its Zn inefficiency. Differential Zn efficiency between the bread wheat cultivars used in this study is not related to their capacity to take up inorganic Zn.
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  • 25
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    Plant and soil 215 (1999), S. 65-72 
    ISSN: 1573-5036
    Keywords: barley ; boron deficiency ; Hordeum vulgare ; Triticum aestivum ; variation ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Responses of a range of barley (Hordeum vulgare L.) genotypes to boron (B) deficiency were studied in two experiments carried out in sand culture and in the field at Chiang Mai, Thailand. In experiment 1, two barley genotypes, Stirling (two-row) and BRB 2 (six-row) and one wheat (Triticum aestivum L.) genotype, SW 41, were evaluated in sand culture with three levels of applied B (0, 0.1 and 1.0 μM B) to the nutrient solution. It was found that B deficiency depressed flag leaf B concentration at booting, grain number and grain yield of all genotypes. In barley Stirling, B deficiency also depressed number of spikes plant-1, spikelets spike-1 and straw yield. However, no significant difference between genotypes in flag leaf B concentration was found under low B treatments. Flag leaf B concentration below 4 mg kg-1 was associated with grain set reduction and could, therefore, be used as a general indicator for B status in barley. In experiment 2, nine barley and two wheat genotypes were evaluated in the field on a low B soil with three levels of B. Boron levels were varied by applying either 2 t of lime ha-1 (BL), no B (B0) or 10 kg Borax ha-1 (B+) to the soil prior to sowing. Genotypes differed in their B response for grain spike-1, grain spikelet-1 and grain set index (GSI). The GSI of the B efficient wheat, Fang 60, exceeded 90% in all B treatments. The B inefficient wheat SW 41 and most of the barley genotypes set grain normally (GSI 〉80%) only at the B+. In B0 GSI of the barley genotypes ranged from 23% to 84%, and in BL from 19% to 65%. Three of the barley with severely depressed GSI in B0 and BL also had a decreased number of spikelets spike-1. In experiment 3, 21 advanced barley lines from the Barley Thailand Yield Nursery 1997/98 (BTYN 1997/98) were screened for B response in sand culture with no added B. Grain Set Index of the Fang 60 and SW 41 checks were 98 and 65%, respectively, and GSI of barley lines ranged between 5 and 90%. One advanced line was identified as B efficient and two as moderately B efficient. The remaining lines ranked between moderately inefficient to inefficient. These experiments have established that there is a range of responses to B in barley genotypes. This variation in the B response was observed in vegetative as well as reproductive growth. Boron efficiency should be considered in breeding and selection of barley in low B soils.
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  • 26
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    Euphytica 108 (1999), S. 91-95 
    ISSN: 1573-5060
    Keywords: amylose content ; granule-bound starch synthase ; null alleles ; Triticum aestivum ; Wx loci
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The Wx locus controls amylose synthesis in the cereal endosperm. Hexaploid wheat (Triticum aestivum L.) has the three Wx loci on chromosomes 7A ( Wx-A1), 4A (Wx-B1) and 7D (Wx-D1). To verify the effects of null alleles on reducing amylose content and determine the amylose synthesis capacity of each Wx gene independently and accurately, we produced eight possible types of recombinant lines carrying different null alleles at the Wx loci under the ‘Chinese Spring’ genetic background. Amylose content varied from 0% of the waxy ‘Chinese Spring’ to 25% of the ‘Chinese Spring’ normal type. The reducing effect of the single null alleles was the largest in Wx-B1b, and there was no significant difference between Wx-A1b and Wx-D1b. More than 3% reductions in amylose content were detected in the double null types. The results of the double null lines further demonstrated that for the capacity of amylose synthesis, Wx-B1a predominates and produces 21–22% amylose, followed by Wx-D1a (20–21%) and Wx-A1a (15–18%). These significant differences were partly correlated with variation in the amounts of the Wx proteins produced by different Wx genes. However, comparisons of the double null lines with the single null or normal lines indicated that amylose content was not linearly proportional to the number of the Wx genes, suggesting that the Wx genes act in an epistatic manner.
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  • 27
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    Plant growth regulation 28 (1999), S. 129-132 
    ISSN: 1573-5087
    Keywords: dormancy ; Lactuca sativa ; lettuce seeds ; Brassica napus ; rapeseed ; combustion products ; Salix viminalis ; Themeda triandra ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In darkness, dormancy was imposed on seeds of lettuce (Lactuca sativa L. cv. Grand rapids) by high temperature and on seeds of oilseed rape (Brassica napus L. cv. Apex) by osmotic stress using polyethylene glycol (PEG 8000). In both cases, dormancy was broken by incubating the seeds in aqueous extracts of combustion products from Salix viminalis wood chips or Themeda triandra leaves. Dormancy of rapeseed, but not lettuce, was also broken by a solution of smoke from burnt straw of Triticum aestivum. The greatest stimulation from burnt vegetation was achieved with an aqueous extract of pyrolysed willow wood chips, which had been subjected to temperatures of up to 800 °C during combustion in a down-draught gasifier. This suggests that some biologically active substances obtained from combustion of plant tissues are highly heat-stable.
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  • 28
    ISSN: 1573-5087
    Keywords: cortical fibre cell ; gibberellic acid ; spring wheat ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The role of gibberellic acid (GA) in differentiation and secondary cell-wall deposition of fibre cells of spring wheat (Triticum aestivum) culms was studied using applications of GA and chlormequat (a GA biosynthesis inhibitor). In certain genotypes, higher GA levels may increase the number of cortical fibre cell files by changing cell fate from parenchyma to fibre, and induce thicker secondary cell-walls.
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  • 29
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    Genetic resources and crop evolution 46 (1999), S. 469-475 
    ISSN: 1573-5109
    Keywords: foliar blight ; germplasm ; resistance ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract One thousand three hundred and eighty-seven spring wheat germplasm (Triticum aestivum L.) lines belonging to the Indian and CIMMYT wheat programmes were evaluated for their tolerance to foliar blight disease for three consecutive years i.e., from 1994 to 1997. Disease severity at six different growth stages, beginning from tillering to late milk stage, was recorded. None of the genotypes showed immunity to the disease. Of 43 lines showing resistant reaction, a major proportion (25) was represented by CIMMYT material. Comparatively, Indian germplasm lines tended to be more susceptible at more advanced growth stages. Area Under Disease Progress Curve (AUDPC) and Apparent Infection Rate (r) values of resistant lines were much lower than those of susceptible ones, but lower AUDPC in some of the resistant lines did not correspond to a lower 'r' value. Most of the resistant lines were derived from Seri, Myna, Bau, kauz, Hork 's' and Aegilops tauschii Coss.
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    Photosynthesis research 59 (1999), S. 1-7 
    ISSN: 1573-5079
    Keywords: leaf gas exchange ; ozone ; Pisum sativum ; Rubisco ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Previous studies have shown that short exposure of plants to high doses of ozone decreases subsequent photosynthesis; initially by reducing carboxylation capacity. This study tests the hypothesis that this is also the primary cause of loss of photosynthetic capacity in leaves affected by development under a low level of ozone. Triticum aestivum and Pisum sativum plants were exposed from germination to ozone in air (80 nmol mol-1 for 7 hours per day, for 18 days. Leaves that had completed lamina expansion at this time were free of visible injury and light absorptance was unaffected. However, some significant changes in photosynthetic gas exchange were evident. Photosynthetic CO2 uptake at light saturation was decreased significantly by 35% in T. aestivum but was unchanged in P. sativum. The reduction in photosynthesis of T. aestivum was accompanied by a 31% decline in the maximum velocity of carboxylation measured in vivo. Decreased stomatal conductance did not contribute to this reduction of photosynthesis because there was no significant change in the stomatal limitation to CO2. Processes directly dependent upon photochemical reactions; that is, the quantum yield of CO2 uptake and capacity for regeneration of ribulose 1,5-bisphosphate were not affected by O3 fumigation in either species. This suggests that for wheat, the quantitative cause of decreased photosynthetic rate in vivo is a decrease in the quantity of active ribulose-1,5- bisphosphate carboxylase-oxygenase.
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    Boundary layer meteorology 91 (1999), S. 495-504 
    ISSN: 1573-1472
    Keywords: Evaporation ; Heat storage ; Marsh ; Inversion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Concurrent measurements of the surface energy balance components (net radiation, heat storage, and sensible and latent heat fluxes) were made in three communities (open water, Phragmites australis, Scirpus acutus) in a wetland in north-central Nebraska, U.S.A., during May-October, 1994. The Bowen ratio – energy balance method was used to calculate latent and sensible heat fluxes. This paper presents results from the open water area. The heat stored in water (G) was found to play a major role in the energy exchange over the water surface. During daytime, G consumed 45–60% of R n , the net radiation (seasonally averaged daytime G was about 127 W m−2). At night, G was a significant source of energy (seasonally averaged nighttime G was about -135 Wm−). The diurnal pattern of latent heat flux (λ E) did not follow that of R n . On some days, λ E was near zero during midday periods with large R n . The diurnal variability in λ E seemed to be significantly affected by temperature inversions formed over the cool water surface. The daily evaporation rate (E) ranged from 2 to 8 mm during the measurement period, and was generally between 70 and 135% of the equilibrium rate.
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  • 32
    ISSN: 1573-1561
    Keywords: Aphid ; experience ; probing behavior ; sieve elements ; salivation ; cell punctures ; hydroxamic acids ; EPG ; Sitobion fragariae ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We hypothesized that aphids after previous exposure to hydroxamic acids (Hx), a family of secondary plant compounds deleterious to aphids, are able to reduce their subsequent exposure to them. This hypothesis was tested by evaluating the time to produce salivation into a sieve element (SSE) by the aphid Sitobion fragariae on seedlings of two wheat cultivars of Triticum aestivum differing in their concentration of Hx. The total time to produce a first SSE was significantly longer in the high-Hx cultivar; however, the subsequent, second SSE (first SSE after interruption of probing) in this cultivar was significantly reduced, reaching the level observed in the low-Hx plants. Therefore, a strategy to reduce the exposure to secondary compounds was observed only in the second SSE in high-Hx plants. When the experimental plant was replaced by a new unattacked plant after the first SSE, aphids did not change the behavior described, thus excluding an aphid-induced plant susceptibility. The number of cell punctures and accumulated duration was not affected by previous exposure to Hx, either in low or high Hx cultivars. Total time and pathway time but not cell punctures, seem to be the variables affected by previous exposure to Hx.
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  • 33
    ISSN: 1573-0867
    Keywords: bicarbonate-extractable soil phosphorus ; Lupinus angustifolius ; residual value ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Decreases in Colwell bicarbonate soil test P in the years after applying single (ordinary) superphosphate, and the residual value of superphosphate, was measured in a long-term field experiment on a duplex (texture contrast) soil (sand over lateritic ironstone gravel clay sand at 10–15 cm), at Wongan Hills, Western Australia, typical of many soils used to grow crops in Western Australia. Ten levels of P (0–91 kg P ha-1) were applied once only in late May to different plots in different years from 1988 to 1993. Wheat (Triticum aestivum), or lupin ( Lupinus angustifolius)) were sown in late May of each year, when the P treatments applied that year were banded (drilled) with the seed. Soil samples were collected each June to measure soil test P. Seed (grain) yields of the crops were measured each December. The residual value (RV) of P applied in previous years was calculated relative to P applied in the current year, using grain yields (RVyield) and soil test P (RVsoil). Soil test P measured on soil samples collected in June was related to yields measured in December that year to provide soil P test calibrations. Relative to P applied in the current year, soil test P decreased by between 15 to 30% for P applied one year previously, by 25 to 30% for P applied three years previously, and by 60 to 70% for P applied six years previously. Soil test P was affected by spatial variation, and it also varied in the different years, for P applied in the current year, one year previously, two years previously, etc. Compared with P applied in the current year, mean RVyield determined in the different years decreased by about 40% one year after P application, followed by a further 20% decrease for P applied two years previously, followed by a further 20% decrease for P applied three to five years previously. Relative to current P, RVsoil decreased by about 25% one year after P application, followed by a further 20% for P applied two years previously, followed by a further 10% for P applied three years ago, and followed by a further 6% for P applied four and five years ago. As measured in the different years, the soil P test calibration varied between years for P applied one, two etc. years previously. This was so even when the same cultivar of wheat was grown at the same site in different years.
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  • 34
    ISSN: 1573-0603
    Keywords: Dichloromethylene diphosphate ; Hepatic stellate cell isolation ; Liposome ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Hepatic perisinusoidal cell population consists of hepatic stellate cells, Kupffer cells, endothelial cells, and Pit cells. These cells are isolated by enzymic digestion and purified by density gradient centrifugation. With isolation of stellate cells, conventional method is unable to eliminate the contamination of Kupffer cells because the densities of these two cells are similar. We report here an improved method for isolation of highly purified hepatic stellate cells, using dichloromethylene diphosphate (CL2MDP), which has selective cytotoxicity of Kupffer cells. Three days after the single intravenous administration of liposome-encapsulated CL2MDP, the Kupffer cells disappeared almost completely from the liver. Following Percoll density gradient centrifugation, the purity of the hepatic stellate cells exceeded 98% without any contamination of the Kupffer cells. Kupffer cells are reported to affect the physiological functions of stellate cells. The availability of highly purified stellate cells will facilitate the investigation of their functions in primary culture.
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  • 35
    ISSN: 1573-5087
    Keywords: flooding ; kinetin ; leaf relative water content ; membrane stability ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Wheat plants, 22d. old, were exposed to wide range of soil water osmotic potential (Ψs = 0 to −1.2 MPa) induced by NaCl and CaCl2 treatments in combination with roots maintained under aerobic (drained at field capacity) or nonaerobic (flooded) conditions in the soil, and sprayed with 10 mg L−1 kinetin solution. In drained plants, not receiving kinetin, increased soil salinity resulted in appreciable inhibition of shoot growth and reduction in chlorophyll (Ch1.), soluble sugars (SS) contents and grain yield. Shoot growth, Ch1. content, soluble sugars and grain yield were significantly lower for flooded plants than unflooded analogues over the entire Ψs range. Both salinity and waterlogging synergize to increase Na+, Ca+ and Cl− accumulation in shoot tissues and to decrease the stability of leaf membranes to either dehydration (40% polyethylene glycol 6000) or heat (51 °C) stress. The ratio of K+/Na+ transported to shoots under aerobic and anaerobic conditions decreased progressively on salinization. The association between the internal mineral element concentrations was largely affected by kinetin treatment. Kinetin application ameliorated the deleterious effects of salinity and oxygen deficiency. It reduced Na+, Ca2+ and Cl− accumulation and improved K+ uptake under salinity and waterlogging stresses. Increased K+/Na+ ratio helped the plants to avoid Na+ toxicity and enhanced shoot growth and grain yield. Kinetin also reduced membrane injury by dehydration and heat stresses and improved the water status of plants under both aerobic and anaerobic conditions. The effects of single factors (Soil salinity ‘Ψs’, soil waterlogging ‘WL’ and Kinetin ‘Kin’) and their interactions (Ψs × WL, Ψs × Kin, WL × Kin and Ψs × WL × Kin) were shown by analysis of variance to be statistically significant for most parameters tested. Calculation of the coefficient of determination (η+) led to three important findings. (1) Salinity (Ψs) was dominant in affecting leaf relative water content (RWC), shoot dry mass, grain yield, stability of leaf membranes to dehydration stress and the contents of Na+, Ca2+, Mg2+ and Cl−. (2) Kinetin (Kin) had a dominant effect on the stability of leaf membranes to heat stress as well as on chlorophyll and soluble sugars contents. (3) The share of waterlogging (WL) was dominant for K+ content. It can be concluded that kinetin application helped wheat plants to grow successfully in the areas subjected to combined effects of salinity and oxygen deficiency, such as in salt marshes.
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  • 36
    ISSN: 1573-5109
    Keywords: Aegilops tauschii ; hairy auricles ; hairy leaf sheath ; inheritance ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Inheritance of genes for hairy auricles and hairy leaf sheath of Ae. tauschii in hexaploid wheat backgrounds (synthetic hexaploid wheat and common wheat varieties) was analyzed. The results indicated that hairy auricles and hairy leaf sheath of Ae. tauschii can be transferred and are expressed in hexaploid wheat. In a synthetic hexaploid wheat ('Ae. tauschii' 188) hairy auricles was proved to be controlled by a single dominant gene derived from Ae. tauschii, which was different from the Pa gene located on chromosome 4BS of common wheat. The hairy leaf sheath phenotype of 'Altar 84/Ae. tauschii 188' was also controlled by a single dominant gene derived from Ae. tauschii, which is obviously different from the Hls gene in T. dicoccoides. We suggest to designate the Ae. tauschii genes for hairy auricles and hairy leaf sheath as Pa2 and Hls2, respectively; such genes could be used as useful genetic markers in common wheat.
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    Plant cell, tissue and organ culture 59 (1999), S. 151-154 
    ISSN: 1573-5044
    Keywords: Ne1 ; Ne2 ; necrotic hybrid ; Triticum aestivum ; viable seeds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Hybrid necrosis in wheat is a problem for gene transfer in wheat breeding. Hybrid necrosis occurs due to dominant complementary interaction of two genes, Ne1 and Ne2. A cross between wheat (Triticum aestivum L.) varieties C306 (drought tolerant, Ne1 carrier) and WL711(high yielding, Ne2 carrier) produced necrotic F1 hybrids, which died before ear emergence and produced no seeds. To overcome the problem of hybrid necrosis, ears enclosed in the leaf sheath were taken and cultured to maturity in liquid medium containing 5% sucrose and 0.04% glutamine. The necrotic hybrids produced only a few seeds per ear compared to parents, but individual grain weight was similar in the hybrid and the parents. The F1 ear culture study has been repeated for three years and F2 seeds obtained. In 1996–97, the cultured ears of F1 hybrids produced 62 seeds, of which only 52 showed germination and were grown under normal field conditions. Out of the 52 seeds, 50% were non-necrotic and showed segregation for various physiological traits. The results reveal that hybrids ears had the potential to form viable seeds. Culturing of wheat ears before ear emergence and production of viable F2 seeds from necrotic hybrids is a simple and efficient method for overcoming the problem of hybrid necrosis.
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    Euphytica 105 (1999), S. 125-131 
    ISSN: 1573-5060
    Keywords: disease resistance ; inheritance ; Karnal bunt ; Neovossia ; Tilletia indica ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Inheritance of resistance to Neovossia indica was studied in a Triticum aestivum line HD 29. To overcome the influence of environment on disease expression, the study was conducted by extensive evaluation of advanced generation (F8) recombinant inbred lines (RILs) developed by single seed descent from the cross WL 711 (susceptible) × HD 29 (resistant. The results suggested that HD 29 possesses three major genes for resistance to isolated Ni7 and two genes for resistance to isolate Ni8. One of the two genes controlling resistance to Ni8 is common with one of the genes conferring resistance to Ni7. These observations have important implications in breeding for Karnal bunt resistance.
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  • 39
    ISSN: 1573-5060
    Keywords: C-banding ; chromosome additions ; chromosome substitution ; Elymus tsukushiense ; homoeology ; in situ hybridization ; RFLP ; Roegneria kamoji ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Elymus tsukushiense Honda (syn. Roegneria kamoji C. Koch) (2n = 6x = 42, StsStsHtsHtsYtsYts) is a hexaploid species, distantly related to bread wheat Triticum aestivum L. em Thell (2n = 6x = 42, AABBDD). Apart from the delineation of evolutionary relationships, this species is a potential source of resistance to scab, a devastating disease of wheat caused by Fusarium graminearum Schw. A standard C-banded karyotype was established identifying all 21 chromosome pairs of E. tsukushiense. By using C-banding and genomic in situ hybridization analyses, three wheat-E. tsukushiense chromosome addition lines, one ditelosomic addition line, and one disomic substitution line were identified in BC2 progenies from wheat × E. tsukushiense hybrids. Twenty DNA markers specific for the seven homoeologous groups of the Triticeae were used to determine the homoeology of the added E. tsukushiense chromosomes. The E. tsukushiense chromosomes in the addition lines NAU702, NAU703, and NAU701 were identified as belonging to homoeologous groups 1, 3, and 5, and thus, were designated as 1Ets#1, 3Ets#1, and 5Ets#1, respectively. NAU751 was identified as a disomic substitution line with chromosome 3A of wheat replaced by chromosome 3Ets#1. Line NAU702 has a high level of resistance to scab and will be used in chromosomal engineering and development of improved wheat germplasm for scab resistance breeding.
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  • 40
    ISSN: 1573-5060
    Keywords: 1BL/1RS ; bread-making quality ; prolamins ; wheat-rye translocations ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The allelic variation of prolamin loci was studied in three F2 progenies from three crosses between the 1BL/1RS cultivar Triana and Yécora Rojo, Pavón and Florence Aurora, cultivars without the translocation. According to the 1:2:1 theoretical proportions observed in the allelic variants of the Glu-B3/Gli-B1 loci of the parent without the translocation, the inheritance as a block of the rye chromosome arm was confirmed. A group of F3-F4 recombinant lines, developed from these crosses was evaluated using the SDS-sedimentation test and the mixograph and alveograph tests. The presence of the 1BL/1RS translocation was not associated with significantly lower grain protein content values or with the optimum mixing time in the mixograph of the genotypes. The effect of the 1BL/1RS translocation on most of the quality parameters was highly dependent on the genetic pool. Significant increases in gluten strength and better mixing properties associated with the presence of some alleles of the Glu-A1, Glu-A3/ Gli-A1 and Gli-D2 loci were detected. The additivity and the interaction of prolamin gene effects with the rye translocation in the 1BL/1RS lines and its possible use in plant breeding are discussed.
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  • 41
    ISSN: 1573-5060
    Keywords: Blumeria graminis ; powdery mildew ; QTL ; RFLPs ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A segregating population of doubled-haploid lines issued from the cross between the wheat (Triticum aestivum L. em. Thell) cultivars Courtot, resistant to several isolates of powdery mildew (Blumeria graminis DC. f. sp. tritici Em. Marchal), and Chinese Spring (susceptible) was used to map Mlar, a gene carried by Courtot and conferring resistance to this pathogen. The assignation of Mlar using monosomic lines of Courtot was confirmed by the mapping analysis. Mlar was located on the short arm of the chromosome 1A, in the vicinity of the locus XGli-A5 coding for storage proteins. This result was in accordance with those demonstrating that Mlar was an allele of the Pm3 locus (Pm3g), a gene also involved in the resistance to powdery mildew.
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  • 42
    ISSN: 1573-5060
    Keywords: disease assessment ; maturity ; resistance ; Septoria tritici ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Nineteen cultivars, with large differences in heading date, were evaluated for their response to septoria tritici blotch in two experimental setups in Njoro, Kenya. Due to the more or less constant temperatures during the growing season and the overhead irrigation applied the epidemic conditions were similar over the whole observation period for the early and late cultivars. In experiment 1 the cultivars were assessed for disease severity at the same moment irrespective of the developmental stage, while in experiment 2 the cultivars were assessed at the same developmental stage. Measured at the same time, the disease severity was highest in the early maturing cultivars and lowest in the late maturing cultivars (r = –0.78). When assessed at the same development stage the disease build up was independent of heading date (r = –0.10) but strongly dependent on resistance level. There were no indications that early heading cultivars were more susceptible than late heading cultivars.
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  • 43
    ISSN: 1573-5060
    Keywords: allelic variation ; glutenin subunit ; Japanese Norin variety ; seed storage protein ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Seed storage proteins of 131 Japanese Norin wheat (Triticum aestivum) varieties were fractionated by sodium dodecyl sulfate polyacrylamide gel electrophoresis to determine allelic make-up in varieties at each of three loci that control high-molecular-weight (HMW) glutenin subunits. Three alleles were identified at the Glu-A1 locus, six at the Glu-B1 locus and five at the Glu-D1 locus. Twenty-four different, major glutenin HMW subunits were identified and each contained three to five subunits and seventeen different glutenin subunit patterns were observed for 19 subunits in the 131 Japanese Norin varieties. Fourteen alleles were identified by comparison of subunit mobility with that previously found in hexaploid wheat. Japanese Norin varieties showed a specific pattern of allelic variation in glutenin HMW subunits, different from that of Chinese and other country common wheats in allelic frequency at Glu-1 loci.
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  • 44
    ISSN: 1573-5036
    Keywords: boron ; genotypic difference ; sterility ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two pot experiments at the Plant Environment Laboratory (PEL), Reading, UK investigated sterility, boron (B) accumulation and B partitioning of wheat cultivars grown with limited B in the growing medium. The first experiment evaluated nine cultivars of spring wheat with diverse field responses to low available soil B, supplied with or without 20 μM B. A second experiment examined the response of a susceptible (SW-41) and a tolerant (Fang-60) cultivar to B-deficiency. These cultivars were supplied with either 20 μM B from sowing to flag leaf emergence and no added B thereafter, or 20 μM B from sowing to maturity. When B was not supplied in the nutrient solution, the number of grains ranged from 4 per ear (cv. BL-1135) to 32 per ear (cv. BL-1249) and sterility of competent florets ranged from 39% to 93%. Boron concentration in the flag leaf at anthesis did not differ greatly when the growing medium contained limited B, but differences between cultivars were evident when B was unlimited. Tolerance of B-deficiency was not related to the B concentration in the flag leaf. Some cultivars produced viable pollen and set grains while others failed to do so at similar B concentrations in the flag leaf. The two contrasting cultivars did not differ much in their pattern of B partitioning when B supply was restricted from flag leaf emergence onwards. Similarly, little evidence was found that the tolerant cultivars translocated B from their leaves, roots or stems when the supply in the growing medium was restricted. The proportion of total B partitioned in different organs was the same irrespective of B supply and cultivar. On average, leaves contained 68% of the total B content in the whole plant compared to 16% in the roots, 10% in the ears and only 6% in the stems. Tolerant or susceptible cultivars of wheat could not be distinguished based on the B concentration and B content of the flag leaf.
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  • 45
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    Plant cell, tissue and organ culture 57 (1999), S. 207-210 
    ISSN: 1573-5044
    Keywords: biolistics ; gene expression ; haploid ; transformation ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Using the PDS-1000/He Biolistic® Particle Delivery System, the microprojectile travel distance, rupture disk pressure and DNA/gold particle concentrations were assessed in order to optimise short and longer-term β-glucuronidase reporter gene expression in microspore-derived embryos of wheat. The effects were also evaluated of using sterile filter paper to support explants and treatment with a high osmoticum medium (0.2 M mannitol/0.2 M sorbitol or 0.4 M maltose). In the optimised procedure, wheat microspore-derived embryos (MDEs), were placed on filter paper and incubated on medium containing 0.4 M maltose, for 4 h pre- and 45 h post-bombardment. Five μl pAHC25 (0.75 mg ml-1 in TE buffer) was precipitated onto 25 μl gold particles (60 mg ml-1 in sterile water), using 20 μl spermidine (0.1 M) and 50 μl CaCl2 (2.5 M). The particles were centrifuged and resuspended in 75 μl absolute ethanol prior to the preparation of 6 macrocarriers. A microprojectile travel distance of 70 mm, a rupture pressure of 1300 p.s.i., and a vacuum of 29′′ Hg were employed. Maltose at 0.4 M in the support medium was the most important factor influencing GUS activity in bombarded tissues. GUS activity, 1 day post-bombardment, reached 52 ± 17 GUS-positive foci/MDE (mean ± s.e.m, n=3), with 17 ± 4 foci/MDE at 15 days, giving a 3.0-fold increase (p〈0.05) compared to expression in MDEs bombarded on medium without a high osmoticum treatment.
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  • 46
    ISSN: 1573-9058
    Keywords: diurnal variation ; photoinhibition ; photosystem 2 reaction centres ; state transition ; trans-thylakoid membrane proton gradient ; Triticum aestivum ; xanthophyll cycle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Non-photochemical quenching of chlorophyll fluorescence (qN) and its three components (qNf, qNm, and qNs) in the flag leaves of wheat grown in the field were studied by a fluorometer PAM-2000 on clear days. The diurnal variation patterns of qN in just fully extended (JFEL) and aging leaves (AL) were similar, but qNm declined markedly in JFEL while it remained at a relatively high level in AL under strong sunlight at noon. Furthermore, at midday qNf was higher than qNs in JFEL, but much lower in AL. The results show the relative contributions of different mechanisms in preventing the photosynthetic apparatus from photodamage change during leaf development.
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  • 47
    ISSN: 1573-9058
    Keywords: D1 protein ; diphenylcarbazide ; oxygen evolving complex ; scavengers ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Irradiation of thylakoid membranes at 40 °C resulted in complete inhibition of photosystem (PS) 2 activity measured as 2,6-dichlorophenol indophenol (DCIP) photoreduction either in the absence or presence of 1,5-diphenylcarbazide (DPC). Concomitant with the inactivation of PS2 activity, several thylakoid proteins were lost and high molecular mass cross-linking products appeared that cross-reacted with antibodies against proteins of PS2 but not with antibodies against proteins of other three complexes PS1, ATP synthase, and cytochrome b6f. Irradiation of thylakoid membranes suspended in buffer of basic pH or high concentration of Tris at 25 °C resulted in the formation of cross-linking products similar to those in thylakoid membranes irradiated at 40 °C. Presence of radical scavengers and DPC during the high temperature treatment prevented the formation of cross-linking products. These results suggest the involvement of oxygen evolving co mplex (OEC) in the formation of cross-linking between PS2 proteins in thylakoid membrane irradiated at high temperature.
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  • 48
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    Photosynthetica 36 (1999), S. 433-440 
    ISSN: 1573-9058
    Keywords: antibody ; polyacrylamide gel electrophoresis ; protease ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Exposure of thylakoid membranes to high temperature in dark leads to the degradation of D1 protein. Maximum degradation of D1 protein occurred at 45 °C. Using N-terminal specific D1 antibody, a 23 kDa fragment of D1 protein was detected. The degradation of D1 protein could be prevented both by radical scavengers and inhibitors of serine protease and metallo-protease. These results suggest that degradation of D1 protein during exposure of thylakoid membranes to high temperature in dark is catalyzed by protease.
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  • 49
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    World journal of microbiology and biotechnology 15 (1999), S. 417-423 
    ISSN: 1573-0972
    Keywords: 15N ; nitrogen mineralization ; Pseudomonas fluorescens ; rhizosphere ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The effects of an antibiotic-producing Pseudomonas fluorescens strain (F113) carrying the marker gene cassette lacZY and a marked, non-producing strain (F113G22) on the uptake of nitrogen from 15N-enriched organic residues incorporated into a sandy soil were investigated in microcosm studies. Strain F113 produces the antibiotic 2,4-diacetylphloroglucinol (DAPG), whilst its modified derivative strain F113G22 has DAPG production deleted by Tn5 mutagenesis. Uptake of nitrogen by wheat (Triticum aestivum) from 15N-enriched organic residues was estimated using stable isotope-ratio mass spectrometry of shoot and root material of 17-day-old plants. In addition, plant growth and active microbial biomass in soil were monitored. In contrast to results obtained in our previous study on pea (Pisum sativum), it was found that in wheat, inoculation with either strain F113 or F113G22 decreased the proportion of nitrogen derived from 15N-labelled organic residues incorporated into soil as compared to non-inoculated controls. It is therefore suggested that these strains decreased mineralization of organic residues in the rhizosphere of wheat, making less inorganic N (15N) available for plant uptake. The results of this study indicate that the effects of introduced Pseudomonas fluorescens strains on nitrogen mineralization in the rhizosphere are plant-species dependent, and highlight the importance of testing microbial inocula on a range of plant species.
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  • 50
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    European journal of plant pathology 105 (1999), S. 917-925 
    ISSN: 1573-8469
    Keywords: ergosterol ; detached glumes ; interaction ; Mycosphaerella graminicola ; Phaeosphaeria nodorum ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Interactions between Stagonospora nodorum and Septoria tritici were studied. Results from a detached glume experiment indicated that the interaction may be isolate-dependent, as it was shown that the interaction between the two pathogens may be beneficial or antagonistic depending on the isolate of each pathogen present. The number of spores produced by both pathogens was significantly greater when an aggressive isolate of S. tritici was mixed with a non-aggressive isolate of S. nodorum, whereas the number of spores produced by both pathogens was significantly less when two non-aggressive isolates were mixed. There was a significant reduction in disease level when S. tritici was applied prior to S. nodorum, compared to vice versa in the growth chamber. Results from growth chamber and field studies showed that S. nodorum produced significantly more spores when both pathogens were present together. It is concluded that S. tritici has a stimulatory effect on spore production by S. nodorum. However, there was a reduction of S. tritici spores observed in the dual inoculation treatments, suggesting that S. nodorum inhibits S. tritici.
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  • 51
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    Biologia plantarum 42 (1999), S. 217-222 
    ISSN: 1573-8264
    Keywords: chlorophyll ; photochemical activity ; photosystem 2 ; ribulose-1,5-bisphosphate carboxylase/oxygenase ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Chlorophyll (Chl) a and b content, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) content and activity, and electron transport rate were measured in flag leaves of wheat genotypes Uniculm and Kalyansona, grown at suboptimal and optimal supply of nitrogen. The Chl content, RuBPCO activity, and electron transport rate were decreased due to suboptimal nitrogen supply only in Kalyansona. There was no change in the ratio of RuBPCO and photosystem 2 (PS2) activity at various stages which suggests that there was no alteration in distribution of N due to additional N supply.
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  • 52
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    Biologia plantarum 42 (1999), S. 119-123 
    ISSN: 1573-8264
    Keywords: anatomy ; epidermis ; heavy metals ; mesophyll ; Triticum aestivum ; vascular bundles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of 1 mM cadmium, lead and nickel on dry mass, Cd, Pb, and Ni contents, and changes in leaf structure in young wheat plants were studied. In leaves, Cd content was highest, followed by Pb and Ni, in roots Cd content was also highest, but followed by Ni and Pb. Roots accumulated considerably larger amounts of the three heavy metals than leaves. Largest reductions of leaf and root mass were obtained with Cd. Pb and Ni effects were almost equal. Ni excess had a strong negative effect on mesophyll thickness, while Cd mostly reduced the number and size of vascular bundles and vessel diameter. High Pb reduced the diameter of vessels causing their different deformations.
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  • 53
    ISSN: 1432-1211
    Keywords: Key words CD1 ; Rat ; Gene ; Organization ; Polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The non-major histocompatibility complex (MHC)-encoded CD1 family has recently emerged as a new antigen-presenting system that is distinct from either MHC class I or class II molecules. In the present study, we determined the genomic structure of the rat CD1 locus. It was extremely similar to mouse CD1 genes, especially to CD1D1. The 5′ flanking region of the CD1 gene contained the binding motifs for two cytokine-inducible transcription factors, NF-IL2-A and NF-IL6. Some regulatory elements found in MHC class I genes (enhancer A, enhancer B, and the IFN response element) were absent. It is of interest that a tyrosine-based motif for endosomal localization found in the human CD1b cytoplasmic tail was encoded by a single short exon which was conserved in all CD1 molecules except for CD1a. Southern blot and direct sequencing analyses of inbred rat strains suggested very limited polymorphism in the 5′ region where a hydrophobic ligand-binding groove is encoded; a single base substitution resulted in amino acid alteration of alanine (GCT) to valine (GTT) at codon 119. Comparison of the overall exon-intron organization of CD1 genes revealed that the length of the intron was also characteristic to each of the two classes of CD1 genes, classic CD1 and CD1D; such categorization has hitherto been made according to the sequence similarity of the coding region. This finding provides further support for the hypothesis that the two classes have different evolutionary histories. In contrast to the complete absence of the classic CD1 in rats and mice, the entire region of nonpolymorphic CD1D has been conserved through mammalian evolution. Similar functional properties of rodent CD1 and human CD1d are implied.
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  • 54
    ISSN: 1432-1211
    Keywords: Key words RT1.S3 ; Grc ; MHC ; Class I ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
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  • 55
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    International journal of biometeorology 41 (1998), S. 101-104 
    ISSN: 1432-1254
    Keywords: Key words Space flight ; Rat ; Plantaris muscle ; GLUT-4 ; Citrate synthase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Abstract  The effects of 14 days of space flight on the glucose transporter protein (GLUT-4) were studied in the plantaris muscle of growing 9-week-old, male Sprague Dawley rats. The rats were randomly separated into five groups: pre-flight vivarium ground controls (PF-VC) sacrificed approximately 2 h after launch; flight groups sacrificed either approximately 5 h (F-R0) or 9 days (F-R9) after the return from space; and synchronous ground controls (SC-R0 and SC-R9) sacrificed at the same time as the respective flight groups. The flight groups F-R0 and F-R9 were exposed to micro-gravity for 14 days in the Spacelab module located in the cargo bay of the shuttle transport system – 58 of the manned Space Shuttle for the NASA mission named ”Spacelab Life Sciences 2”. Body weight and plantaris weight of SC-R0 and F-R0 were significantly higher than those of PF-VC. Neither body weight nor plantaris muscle weight in either group had changed 9 days after the return from space. As a result, body weight and plantaris muscle weight did not differ between the flight and synchronous control groups at any of the time points investigated. The GLUT-4 content (cpm/µg membrane protein) in the plantaris muscle did not show any significant change in response to 14 days of space flight or 9 days after return. Similarly, citrate synthase activity did not change during the course of the space flight or the recovery period. These results suggest that 14 days of space flight does not affect muscle mass or GLUT-4 content of the fast-twitch plantaris muscle in the rat.
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  • 56
    ISSN: 1432-203X
    Keywords: Key words Bread wheat ; Triticum aestivum ; Tritordeum ; Tissue electroporation ; Transient gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Wheat scutella and tritordeum inflorescences were transformed by tissue electroporation with plasmid DNA containing a β-glucuronidase (GUS) gene (gus A) under the control of the rice actin1 promoter. Factors affecting electroporation efficiency were analysed. Important factors were electroporation voltage and pulse length, the volume of electroporation buffer, the osmoticum of electroporation buffer and medium, the osmoticum of pre-electroporation culture medium, and pre-electroporation incubation time and temperature. Maximum transient gene expression was obtained with a single pulse of 550 V/cm from a 960-μF capacitor, using 200 μl of electroporation buffer, after 2–3 h culture on media with 357 mOsm for wheat scutella or 1 day on media with 222 mOsm for tritordeum inflorescences, and 0.5–1 h pre-electroporation incubation with DNA at 24 °C. Under these conditions, up to 90% of the explants showed GUS expression, and up to 149 expression signals were recorded per replicate. Electroporated explants showed high rates of survival and retained the ability to regenerate plants via somatic embryogenesis.
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  • 57
    ISSN: 1432-2242
    Keywords: Key words Aegilops markgrafii ; Triticum aestivum ; Addition lines ; Chromosome markers ; Homoeology ; Wheat ; Wheat microsatellites
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We describe the use of wheat microsatellites for the discrimination of Aegilops markgrafii chromosomes. Twenty out of eighty eight wheat microsatellites (WMS) tested were able to distinguish Triticum aestivum-Ae. markgrafii addition lines. Six, three, three, one and six of 18 WMS can be used as markers for single Ae. markgrafii chromosomes B, C, D, F and G, respectively. Addition line A is not available but additional bands, appearing only in Ae. markgrafii and the T. aestivum-Ae. markgrafii amphiploid and not in any of the available addition lines, indicate that three WMS detect markers for Ae. markgrafii chromosomes A. Addition line E could not be detected by any of the WMS markers applied, although the 20 WMS represented all the homologous groups of wheat. All three WMS located on the short arm of group-2 chromosomes were located on Ae. markgrafii chromosome B; three of four WMS, located on the long arm of wheat group-2 chromosomes, were specific to Ae. markgrafii chromosome G and three of four WMS, specific to group-5 chromosomes, were markers for Ae. markgrafii chromosome C, indicating the homoeology of these wheat chromosome arms with the respective Ae. markgrafii chromosomes.
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  • 58
    ISSN: 1432-2242
    Keywords: Key words RFLP analysis ; Triticum aestivum ; Genetic diversity ; Genetic similarity estimates ; Cluster analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Restriction fragment length polymorphisms (RFLPs) have been used to characterise the genetic diversity of wheat (Triticum aestivum) germplasm. One hundred and twenty-four accessions comprising all major Australian wheat varieties and lines important for breeding purposes were assayed for RFLPs with clones of known genetic location and selected to give uniform genome coverage. The objectives of this study were to determine RFLP-based genetic similarity between accessions and to derive associations between agronomically significant traits and RFLP phenotypes. Ninety-eight probes screened against genomic DNA digested with five restriction endonucleases detected a total of 1968 polymorphic fragments. Genetic similarity (GS) calculated from the RFLP data ranged from 0.004 to 0.409 between accessions, with a mean of 0.18. Cluster analysis based on GS estimates produced four groupings that were generally consistent with available pedigree information. Comparisons of the RFLP phenotypes of accessions containing disease resistance genes present on introgressed alien segments enabled the identification of specific alleles characteristic of these regions. Associations were derived for a range of stem-rust, leaf-rust and yellow-rust resistance genes. These results suggest that RFLP analysis can be used for the characterisation and grouping of elite breeding material of wheat and RFLP profiling can identify chromosome segments associated with agronomic traits.
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  • 59
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    Theoretical and applied genetics 96 (1998), S. 69-75 
    ISSN: 1432-2242
    Keywords: Key words Aegilops umbellulata ; Co-linearity ; Comparative mapping ; Translocations ; Triticum aestivum ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  A comparative genetic map of Aegilops umbellulata with wheat was constructed using RFLP probes that detect homoeoloci previously mapped in hexaploid bread wheat. All seven Ae. umbellulata chromosomes display one or more rearrangements relative to wheat. These structural changes are consistent with the sub-terminal morphology of chromosomes 2 U, 3 U, 6 U and 7 U. Comparison of the chromosomal locations assigned by mapping and those obtained by hybridization to wheat/Ae. umbellulata single chromosome addition lines verified the composition of the added Ae. umbellulata chromosomes and indicated that no further cytological rearrangements had taken place during the production of the alien-wheat aneuploid lines. Relationships between Ae. umbellulata and wheat chromosomes were confirmed, based on homoeology of the centromeric regions, for 1 U, 2 U, 3 U, 5 U and 7 U. However, homoeology of the centromeric regions of 4 U with wheat group-6 chromosomes and of 6 U with wheat group-4 chromosomes was also confirmed, suggesting that a re-naming of these chromosomes may be pertinent. The consequences of the rearrangements of the Ae. umbellulata genome relative to wheat for gene introgression are discussed.
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  • 60
    ISSN: 1432-2242
    Keywords: Key words Fluorescence in situ hybridization ; Translocation ; WSMV resistance ; Thinopyrum intermedium ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract   Thinopyrum intermedium is a promising source of resistance to wheat streak mosaic virus (WSMV), a devastating disease of wheat. Three wheat germplasm lines possessing resistance to WSMV, derived from Triticum aestivum×Th. intermedium crosses, are analyzed by C-banding and genomic in situ hybridization (GISH) to determine the amount and location of alien chromatin in the transfer lines. Line CI15092 was confirmed as a disomic substitution line in which wheat chromosome 4A was replaced by Th. intermedium chromosome 4Ai?2. The other two lines, CI17766 and A29-13-3, carry an identical Robertsonian translocation chromosome in which the complete short arm of chromosome 4Ai?2 was transferred to the long arm of wheat chromosome 4A. Fluorescence in situ hybridization (FISH) using ABD genomic DNA from wheat as a probe and S genomic DNA from Pseudoroegneria stipifolia as the blocker, and vice versa, revealed that the entire short arm of the translocation was derived from the short arm of chromosome 4Ai?2 and the breakpoint was located at the centromere. Chromosomal arm ratios (L/S) of 2.12 in CI17766 and 2.15 in A29-13-3 showed that the translocated chromosome is submetacentric. This translocated chromosome is designated as T4AL ⋅ 4Ai?2S as suggested by Friebe et al. (1991).
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  • 61
    ISSN: 1432-2242
    Keywords: Key words Triticum spelta ; Triticum aestivum ; SDS-PAGE ; Acid-PAGE ; Seed storage proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Seed storage proteins of a few selected spelt forms and crosses have already been electrophoretically analysed by SDS-PAGE and acid-PAGE and compared with a few winter wheat cultivars. In the analyses presented here further important Central European spelt varieties were included, as well as modern winter wheat cultivars which were chosen as standards. In this study gliadin and glutenin band patterns of modern Central European winter wheat cultivars were analysed, in particular for a comparison with spelt varieties. An improved differentiation within and between the two species was obtained.
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  • 62
    ISSN: 1432-2242
    Keywords: Key words Genetic diversity ; Triticum tauschii ; Triticum aestivum ; RFLP ; Landrace wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Chinese accessions of Triticum tauschii and T. aestivum L. from the Sichuan white (SW), Yunnan hulled (YH), Tibetan weedrace (TW), and Xinjiang rice (XR) wheat groups were subjected to RFLP analysis. T. tauschii and landraces of T. aestivum from countries in Southwest Asia were also evaluated. For T. tauschii, a west to east gradient was apparent where the Chinese accessions exhibited less diversity than those from Southwest Asia. Compared to the Southwest Asian gene pool, the Chinese T. tauschii was highly homogeneous giving a low frequency of polymorphic bands (16%) and banding patterns (1.33 per probe) with 75 RFLP probe-HindIII combinations. Accessions of T. tauschii from Afghanistan and Pakistan were genetically more similar to the Chinese T. tauschii than those from Iran. Of 368 bands found for 39 Chinese hexaploid wheat accessions with 63 RFLP probe-HindIII combinations, 28.3% were polymorphic with an average of 2.6 banding patterns per probe and 5.0 bands per genotype. The individual Chinese landrace wheat groups revealed less variation than those from Afghanistan, Iran, and Turkey. When classified into country based groups, however, the diversity level over all Chinese landraces was greater than that of some Southwest Asian landraces, especially those from Afghanistan and Iran . The XR wheat group was genetically distinct from the other three Chinese landrace groups and was more related to the Southwest Asian landraces. The TW group was genetically similar to, but more diverse than, the SW and YH groups. The Chinese landraces had a higher degree of genetic relatedness to the Southwest Asian T. tauschii, particularly to accessions from Iran, rather than to the Chinese T. tauschii. ‘Chinese Spring’ was most related to ‘Chengdu-guang-tou’, a cultivar from the SW wheat group.
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  • 63
    ISSN: 1432-2242
    Keywords: Key words Aegilops triuncialis ; Triticum aestivum ; Heterodera avenae ; Cereal cyst nematode ; Resistance gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The cereal cyst nematode (Heterodera avenae) is an important root parasite of common wheat. A high level of resistance was transferred to wheat from Aegilops triuncialis (TR lines) using the cross [(T. turgidum×Ae. triuncialis)×T. aestivum]. Low fertility (3–5 viable kernels per plant) was observed during the process but the surviving hybrid plants were highly vigorous. To obtain stable resistant lines further crosses to T. aestivum were performed. The resistance in TR lines seems to be transferred from the C genome of Ae. triuncialis (genomes CCUU). Ae. triuncialis was highly resistant to the two Spanish populations of H. avenae tested, as well as to four French races and two Swedish populations. The histological analysis showed a hypersensitive reaction in the roots of a resistant TR line inoculated with the Ha71 pathotype of H. avenae, whereas well-formed syncytia were observed in the roots of the susceptible control. Resistance to the H. avenae Ha71 pathotype seemed to be inherited as determined by a single dominant factor in the crosses between resistant TR lines and susceptible cultivars.
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  • 64
    ISSN: 1432-0878
    Keywords: Key words N18-RE-105 cells ; Glutamate ; p53 ; Adriamycin ; Etoposide ; Differentiation ; SV40 large T antigen ; Mouse ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Process extension was induced in cells of the N18-RE-105 neuroblastoma-retinal hybrid line by toxic agents, including glutamate and the p53-inducing anticancer agents adriamycin and etoposide. Both adriamycin and glutamate activated p53 as measured by a plasmid transfection assay. It was therefore hypothesized that SV40 large T antigen, which binds p53, would interfere with cellular differentiation. To test this hypothesis, the temperature-sensitive form of SV40 large T was transduced into N18-RE-105 cells by retroviral infection. SV40 large T-infected cells became de-differentiated, grew in tightly-packed colonies, lost expression of neurofilament, and lost the ability to differentiate in response to glutamate and adriamycin. The de-differentiating effect of SV40 large T antigen may be due to binding and inactivation of cellular proteins, such as p53, p107, p130, p300, and retinoblastoma protein, which are important in cellular growth and differentiation. It is suggested that p53 may play a role in cellular differentiation, perhaps under unusual circumstances involving stress or cytotoxicity.
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  • 65
    ISSN: 1432-0878
    Keywords: Key words Elastin ; TGF-β1 ; Arteries ; In situ hybridization ; Immunohistochemistry ; Northern blot ; Ageing ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Several in vitro studies have previously demonstrated that the addition of TGF-β to aortic smooth muscle cells or skin fibroblasts stimulates elastin synthesis. It is not clear however whether, in vivo, TGF-β participates in the regulation of elastin synthesis, especially in physiological conditions. The aim of our study was to explore the localization of elastin mRNA and TGF-β1 in the rat thoracic aorta (an elastic artery) and caudal artery (a muscular artery). Elastin mRNA was localized by in situ hybridization and quantified using Northern blot analysis. TGF-β1 was detected using immunohistochemistry. The study was carried out as a function of age (rats of 3, 10, 20, and 30 months). We observed that TGF-β1 immunoreactivity is present predominantly, but not exclusively, at the sites of elastin synthesis as determined by elastin mRNA detection: in smooth muscle cells in the aorta and in endothelial cells in the caudal artery. The ability of exogenously added TGF-β1 (0.001–10 ng/ml) to modulate the steady-state levels of elastin mRNA in primary cultures of endothelial cells, smooth muscle cells, and fibroblasts isolated from the thoracic aorta was also studied. At the highest concentration used, elastin mRNA levels increased 5-fold in endothelial cells and 11-fold in smooth muscle cells. The demonstration that TGF-β1 immunoreactivity is present at the sites of elastin synthesis in the thoracic aorta and in the caudal artery and the observation that TGF-β1 induces an increase in elastin mRNA levels in cultured endothelial cells and smooth muscle cells suggest that TGF-β1 may be implicated, at least in part, in the physiological regulation of elastin gene expression.
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  • 66
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    Cell & tissue research 291 (1998), S. 445-454 
    ISSN: 1432-0878
    Keywords: Key words Serum-free medium ; Survival ; Chondroitin sulfate ; Culture substratum ; Brain neuron ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  When cells dissociated from the neonatal rat brains are plated on a poly-lysine-coated surface in a serum-free medium, they display a strange morphology: a dark and extended cell body. Preincubation of the surface with fetal bovine serum was found to inhibit the appearance of this strange contraction of the basal cell sheets in a dose-dependent manner. This finding indicated the presence of a factor(s) in the serum, which might be an appropriate substratum for prolonged survival of brain neurons. In the current study, this factor was highly purified through DEAE ion-exchange chromatography followed by gel filtration. The factor was eluted from a Superose column at fractions corresponding to a molecular weight greater than 1000 kDa. By SDS-PAGE analysis, these fractions were found to contain a major band (≥1000 kDa) positive for alcian blue and few minor bands faintly stainable with Coomassie blue. The activity of the purified sample, inducing the morphological change in cells, was diminished by incubation with chondroitinase ABC. Neither heparitinase II, hyaluronidase, nor trypsin modified the activity. An authentic chondroitin sulfate (type B) mimicked the serum action on the morphology of brain cells in early stages of culture. Taking these findings together, it is suggested that the factor in serum beneficial for the attachment of brain cells is composed of a chondroitin sulfate with a Mr greater than 1000 kDa. Cortical cells dissociated from the neonatal rat brain attached well to the purified factor-coated surface and displayed a healthy morphology: an optically-reflective cell body with thick neurites for at least 3 days in the absence of serum.
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  • 67
    ISSN: 1432-0878
    Keywords: Key words Retina ; Rod bipolar cells ; Amacrine cells ; Protein kinase C ; Glutamic acid decarboxylase ; GABA ; Synaptic circuitry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The synaptic connectivity between rod bipolar cells and GABAergic neurons in the inner plexiform layer (IPL) of the rat retina was studied using two immunocytochemical markers. Rod bipolar cells were stained with an antibody specific for protein kinase C (PKC, α isoenzyme), and GABAergic neurons were stained with an antiserum specific for glutamic-acid decarboxylase (GAD). Some amacrine cells were also labeled with the anti-PKC antiserum. All PKC-labeled amacrine cells examined showed GABA immunoreactivity, indicating that PKC-labeled amacrine cells constitute a subpopulation of GABAergic amacrine cells in the rat retina. A total of 150 ribbon synapses established by rod bipolar cells were observed in the IPL. One member of the postsynaptic dyads was always an unlabeled AII amacrine cell process, and the other belonged to an amacrine-cell process showing GAD immunoreactivity. The majority (n=92) (61.3%) of these processes made reciprocal synapses back to the axon terminals of rod bipolar cells. In addition, 78 conventional synapses onto rod bipolar axons were observed, and among them 52 (66.7%) were GAD-immunoreactive. Thus GABA provides the major inhibitory input to rod bipolar cells.
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  • 68
    ISSN: 1432-0878
    Keywords: Key words PC12 ; hNT2 ; Neuroblastoma cell lines ; NGF ; Retinoic acid ; Rat ; Human cell lines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Neuroendocrine-specific protein (NSP) reticulons are expressed in neural and neuroendocrine tissues and cell cultures derived therefrom, while most other cell types lack NSP-reticulons. Three major subtypes have been identified so far, designated NSP-A, NSP-B, and NSP-C. We have investigated the correlation between the degree of neuronal differentiation, determined by morphological and biochemical criteria, and NSP-reticulon subtype expression. For this purpose, several human neuroblastoma cell lines, exhibiting different degrees of neuronal differentiation, were examined immuno(cyto) chemically. It became obvious that the expression of NSP-C, as detected by immunofluorescence microscopy and Western blotting, is most prominent in cell lines with a high degree of neuronal differentiation, such as LA-N-5. Such highly differentiated cells also express other neural and neuroendocrine markers, such as neural cell adhesion molecule (NCAM), neurofilament proteins, synaptophysin, and chromogranin. NSP-A was observed in all cell lines to a different extent. However, no clear correlation was observed with the degree of neuronal differentiation as defined by other neuronal and neuroendocrine markers or morphology. NSP-B could not be detected. The induction of neuronal differentiation with nerve growth factor, dbcAMP, and retinoic acid in the rat pheochromocytoma cell line PC12 and the human teratocarcinoma cell line hNT2, respectively, induced the expression of NSP-A and NSP-C in these cell lines parallel to the induction of neurofilament protein expression. It is concluded that NSP-C expression, in particular, is strongly correlated with neuronal differentiation.
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  • 69
    ISSN: 1432-0878
    Keywords: Key words Osteoclasts ; Osteoblasts ; Osteocytes ; Bone ; Substance P (SP) ; Neurokinin-1 receptor (NK1-R) ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Substance P (SP) is a neuropeptide that is released from axons of sensory neurons and causes signal transduction through the activation of the neurokinin-1 receptor (NK1-R). The present study demonstrates the distribution of SP-like-immunoreactive (SP-LI) axons and the localization of NK1-Rs in rat bone tissue using the avidin-biotin-peroxidase complex method. Axons with SP-LI were commonly found near the trabecular bone in the temporal bone marrow, but they were only sparsely distributed in the mandible, femur, and tibia. Immunoreactivity for NK1-Rs was found on the plasma membrane and in the cytoplasm of the osteoclasts. In the osteoblasts and osteocytes, a small number of weak, punctate immunoreactive products of NK1-Rs were distributed close to the plasma membrane. At the electron-microscopic level, immunoreactivity for NK1-R was distributed mainly in the whole cytoplasm, except for the clear zone of the osteoclasts, and in pit-like structures along the plasma membrane. The NK1-R-immunoreactive structures in the cytoplasm were divided into two types of organelles, consisting of vesicular and vacuolar structures (probably transport vesicles and early endosomes). In the osteoblasts and osteocytes, the number of NK1-R-positive vesicular structures was fewer than in the osteoclasts. These results thus suggest that SP secreted by the sensory axons could directly modulate bone metabolism via NK1-Rs.
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  • 70
    ISSN: 1432-0878
    Keywords: Key words Vinculin ; Talin ; Integrin ; Dystrophin ; Spectrin ; T-tubule ; Costamere ; Basal membrane ; Cardiac muscle cell ; Dilated cardiomyopathy ; Human ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The transverse tubule system of the cardiomyocyte remains undeformed despite the extreme forces it undergoes during the contraction-relaxation cycle, but the morphological basis for its stability remains unclear. Therefore, we have investigated the architecture and subcellular protein scaffold of the cardiac T-tubules and compared it with that of the costameres and of the free sarcolemma. Tissue samples from normal rat and monkey hearts, and left ventricular tissue from normal and cardiomyopathic human hearts obtained at transplantation surgery were investigated using immunocytochemistry and confocal microscopy and by electron microscopy. In addition, we used a re-differentiation model of isolated, cultured adult rat cardiomyocytes. The cell membrane of the cardiac T-tubules was found to contain the cell-matrix focal adhesion molecules (FAMs) vinculin, talin, the α5β1 integrin and the membrane-associated proteins (MAPs) dystrophin and spectrin. FAMs and MAPs were localized in the T-tubular membrane in a similar pattern: in longitudinally oriented myocytes as transverse punctate lines at the Z-level; in transversally cut myocytes a radial tubular network was found to extend throughout the interior of the cell. Immunolabeling for basement membrane components including collagen IV, fibronectin and laminin showed a colocalization with FAMs and MAPs parallel to the transverse T-tubules. The costameres of the sarcolemma showed a protein composition resembling that of the T-tubules but the intervening segments of free sarcolemma showed absence of FAMs and presence of MAPs. For the first time, we demonstrate the existence and protein composition of the T-tubular scaffold in the human heart. Furthermore, we show that cardiomyocytes from human failing hearts have less abundant but more dilated T-tubules than do experimental animals. These results indicate that the cardiac T-tubular system contains a subcellular scaffold closely resembling that of the costameres. It consists of FAMs, MAPs and basal lamina proteins that confer structural integrity to the cardiac T-tubular membrane during contraction/relaxation cycles.
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  • 71
    ISSN: 1432-0878
    Keywords: Key words Pancreas ; Stomach ; Duodenum ; Ribonuclease protection assay ; Immunocytochemistry ; Protease ; Rat ; (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Prior studies have revealed the presence of chymotrypsinlike protease in peripheral organs, although no definitive evidence for the synthesis of this enzyme in tissue other than the pancreas is available. In an attempt to detect chymotrypsinogen mRNA in peripheral organs, a fragment of the pancreatic chymotrypsin mRNA from rat was amplified using PCR. The sequence was identified as a portion of the rat chymotrypsin B gene overlapping exon 5 through exon 7. It was subcloned into the pGEM-4Z vector and used as a template for the vitro transcription of an antisense riboprobe. Using ribonuclease protection and Northern blot analyses, chymotrypsin mRNA was detected in the rat pancreas, stomach, duodenum, ovary, and spleen. Monoclonal and polyclonal antisera against chymotrypsin detected chymotrypsinlike immunoreactivity in rat and human pancreas, rat stomach, duodenum and jejunum. Electrophoresis and immunoblotting revealed chymotrypsin-chymotrypsinogen bands (25–29 kDa) in the stomach and duodenum. Synthesis of a potent protease such as chymotrypsin in tissue other than pancreas is significant, suggesting a potential physiological and/or pathological role in these tissues.
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  • 72
    ISSN: 1432-0878
    Keywords: Key words Connexin ; Gap junctions ; Smooth muscle ; Intestinal pacemaker ; Confocal laser scanning microscope ; Dog ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Cellular networks of pacemaker activity in intestinal movements are still a matter of debate. Because gap-junctional intercellular communication in the intestinal wall may provide important clues for understanding regulatory mechanisms of intestinal movements, we have attempted to clarify the distribution patterns of three types of gap junction proteins. Using antibodies for connexin40, connexin43, connexin45, smooth muscle actin, and vimentin, immunocytochemical observations were made with the confocal laser scanning microscope on cryosections of fresh-frozen small intestine and colon of the dog and rat. Connexin 45 was localized along the deep muscular plexus of the small intestine in both dog and rat. Double labeling studies revealed that connexin45 overlapped with vimentin –, but not actin-positive areas, indicating the fibroblast-like nature of the cells, rather than their being smooth muscle-like. Connexin43 immunoreactivity appeared along the smooth muscle cell surface in the outer circular layer of the small intestine of both animals. Connexin 40 immunoreactivity was not observed in the muscle layer other than in the wall of large blood vessels. It is suggested that connexin45-expressing cells along the deep muscular plexus of dog and rat small intestine are likely to act as a constituent of a pacemaker system, which may include a conductive system, by forming a cellular network operating via specific types of gap junctions.
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  • 73
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    Cell & tissue research 292 (1998), S. 613-617 
    ISSN: 1432-0878
    Keywords: Key words Sensory nerve endings ; Calretinin ; Laryngeal mucosa ; Immunohistochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution of laminar nerve endings that contained immunoreactive calretinin was examined in the laryngeal mucosa of the adult rat. In whole-mount preparations, the immunoreactive laminar endings were distributed in the supraglottic region but not in the subglottic region. The laminar endings that arose from thick nerve fibers with or without swellings were identified as corpuscles with many variform terminal arborizations. They appeared to be located at the interface between the epithelium and the subepithelial connective tissue. The terminals were scattered under the basal lamina of the epithelium, and some of them were located within the epithelial layer. Immunoelectron microscopy revealed that both sub- and intraepithelial immunoreactive terminals that were filled with mitochondria were partly or totally ensheathed by Schwann cell processes. The denervation experiments, in which the superior laryngeal nerve was cut unilaterally or bilaterally, suggested that the laminar endings originate from the superior laryngeal nerve with strict ipsilateral innervation. The laminar endings might be associated with detection of changes in pressure in the laryngeal cavity or chemical stimuli.
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  • 74
    ISSN: 1432-0878
    Keywords: Key words Adhering junctions ; Desmosomes ; Endothelial junctions ; Plaque proteins ; Desmoplakin ; Cadherins ; Protein ZO-1 ; Rat ; cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Two major types of plaque-bearing adhering junctions are commonly distinguished: the actin microfilament-anchoring adhaerens junctions (AJs) and the desmosomes anchoring intermediate-sized filaments (IFs). Both types of junction usually possess the common plaque protein, plakoglobin, whereas the other plaque proteins and the transmembrane cadherins are mutually exclusive. For example, AJs contain E-, N-, or P-cadherin in combination with α- and β-catenin, vinculin and α-actinin, whereas in desmosomes, desmogleins and desmocollins are associated with desmoplakin and one or several of the plakophilins (PP1–3). Here we describe a novel type of adhering junction comprising proteins of both AJs and desmosomes and the tight junction (TJ) plaque protein, ZO-1, in a newly established, liver-derived tumorigenic rat cell line (RMEC-1). By immunofluorescence microscopy, cell-cell contacts are characterized by mostly continuous-appearing lines which are usually resolved by electron microscopy as extended arrays of closely spaced small plaque subunits. These plaque-covered regions are positive for plakoglobin, α- and β-catenin, the arm-repeat protein p120, vinculin, desmoplakin and protein ZO-1. They are positive for E-cadherin in cultures early on in passaging, but tend to turn negative for all known cadherins in densely grown cultures. On immunoblotting SDS-PAGE-separated proteins from dense-grown cell monolayers, “pan-cadherin” antibodies have reacted with a band at ∼140 kDa, identified as N-cadherin by peptide fingerprinting of the immunoprecipitated protein, which for reasons not yet clear is modified or masked in immunolocalization experiments. The exact histological derivation of RMEC-1 cells is not known. However, the observations of several endothelial markers and the fact that all cells are rich in IFs containing vimentin and/or desmin, while only subpopulations also reveal IFs containing CKs 8 and 18, is suggestive of a mesenchymal, probably endothelial origin. We discuss the molecular relationship of this novel type of extended junction with other types of adhering junctions.
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  • 75
    ISSN: 1432-0878
    Keywords: Key words Nerve growth factor ; Hypertension ; Contact inhibition ; Proliferation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Elevated target-derived smooth muscle nerve growth factor (NGF) and resultant neurogenic plasticity are associated with both hypertension and hyperactive voiding in spontaneously hypertensive rats (SHRs: hypertensive, behaviorally hyperactive). In culture, vascular (VSMCs) and bladder (BSMCs) smooth muscle cells derived from SHRs secrete higher levels of NGF, proliferate more rapidly, and achieve higher density at confluence than do control Wistar-Kyoto (WKY) cells. To elucidate growth-related contributions to the elevated tissue NGF observed in SHRs, we examined vascular VSMC and BSMC NGF secretion in two inbred cell lines (WKHTs, hypertensive; WKHAs, hyperactive) derived from SHRs and WKYs to assess the phenotypic association of altered NGF metabolism with either hypertension or behavioral hyperactivity. Cell density, rather than growth rates, was the most important factor with respect to NGF secretion. VSMC density varied such that WKHT=SHR〉WKY= WKHA, higher VSMC density being associated with higher NGF output. However, in BSMC cultures, NGF output was the lowest in high density cell lines, with WKHT〉SHR〉WKY〉WKHA. SHR BSMCs had the second highest cell density and NGF secretion level. Elevated packing density, presumably because of a lack of contact inhibition, co-segregated with the hypertensive phenotype in both VSMCs and BSMCs. Thus, dysfunctional smooth muscle growth characteristics may contribute to the augmented vascular and bladder NGF content associated with high blood pressure and hyperactive voiding in SHRs.
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  • 76
    ISSN: 1432-0878
    Keywords: Key words Endothelial cells ; Alkaline phophatase ; Primary cultures ; Proliferation ; Gene expression ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Primary cultures of rat myocardial capillary endothelial cells were established and characterized. A range of typical endothelial cell-specific markers were retained in vitro. Cell kinetic studies in confluent endothelial-cell cultures in vitro revealed a roughly 50-fold increase in the proportion of cells in s-phase, indicating a very considerable shortening of cell turnover time, compared to in vivo conditions. Alkaline phosphatase enzyme activity and encoding mRNA are strongly expressed in myocardial capillary endothelial cells in vivo, but were not detectable in vitro. This was true in cell cultures from two strains of rat, which revealed significantly different enzyme expression levels in vivo. In co-cultures of pericytes and endothelial cells, positive ALP enzyme reaction was detected in pericytes, which in vivo show only very weak enzyme reactivity. Treatment of cell cultures with ≤10 M retinoic acid had no effect in pure endothelial cell cultures, but did increase ALP expression of pericytes in co-cultures. The observation of a loss of endothelial ALP expression in vitro supports other in vitro as well as our own in vivo observations, indicating a negative correlation of ALP expression and proliferative activity of endothelial cells.
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  • 77
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    Cell & tissue research 291 (1998), S. 575-579 
    ISSN: 1432-0878
    Keywords: Key words Chromatoid body ; Polysomes ; RNA ; Spermatid ; Spermatogenesis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  A procedure for isolating the chromatoid body from the testis of 40-day-old rats was developed. Electron-microscopical analysis indicated that about 70% of the isolated organelles were chromatoid bodies, while the remaining structures corresponded to dense bodies and probably to satellites. Negative staining of the isolated organelles revealed the presence of polysome-like structures in about 20% of the chromatoid bodies suggesting that the polysomes were not due to contamination with cytoplasmic polysomes. Moreover, the presence of RNA in the stroma of the chromatoid body was confirmed by RNAse-gold staining. Preliminary electrophoretic analysis of the RNA extracted from the organelles revealed the presence of a complex population of RNAs including 5.8 and 5 S ribosomal RNAs but no tRNA.
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  • 78
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    Cell & tissue research 292 (1998), S. 367-375 
    ISSN: 1432-0878
    Keywords: Key words Larynx ; Edema ; Mast cells ; Compound 48/80 ; Substance P ; Capsaicin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  In the rat larynx, plasma exudation and edema formation were studied by light and electron microscopy after i.v. injections of the mast cell activator compound 48/80, substance P, and capsaicin. The morphological effects of substance P and capsaicin on connective tissue mast cells in vivo were also examined. Of the drugs tested, only compound 48/80 degranulated the connective tissue mast cells. All drugs induced a subepithelial plasma exudation in the subglottic region, with edema in the lamina propria and widened intraepithelial intercellular spaces, though the tight junction regions seemed intact. In the epiglottis, 10 min after compound 48/80 injection, there was edema in the lamina propria on the lingual side, with an intact and tight epithelial lining. No morphological sign of edema was found in the epiglottis after injection of substance P or capsaicin. The pronounced effect found in the epiglottic region after compound 48/80 injection was due to the release of mediators such as histamine and 5-hydroxytryptamine from the connective tissue mast cells. This study supports the belief that substance P in vivo mediates an increased vascular permeability by a direct effect on the blood vessels – a mechanism distinct from mast cell degranulation.
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  • 79
    ISSN: 1432-0878
    Keywords: Key words Angiogenesis ; Capillary growth ; Prazosin ; Shear stress ; Skeletal muscle ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Chronic vasodilatation represents a stimulus for capillary growth associated with increased luminal shear stress. We have examined the ultrastructure of more than 2000 capillaries to establish whether the sequence of angiogenesis in response to this stimulus is similar to that described during development and under pathological circumstances. Administration of the α1-blocker prazosin to rats for 2 weeks led to a greater capillary length density in extensor hallucis proprius muscles without any change in capillary tortuosity: J v(c,f)=262±54 compared with 350±17 mm–2, control compared with prazosin (P〈0.002). There were obvious signs of endothelial cell (EC) activation after prazosin treatment, including an increased proportion of capillaries with rough endoplasmic reticulum, large cytoplasmic vacuoles, thickened endothelium and an irregular luminal surface. Capillaries from control muscles had a maximum of three ECs in cross section, whereas four ECs were noted in 0.8+0.5% of capillaries after 1 week (n.s.) and 2.5±0.9% after 2 weeks (P〈0.01) of treatment. This could be due to elongation and/or migration of ECs, as cell proliferation has not been described at these time points. There was also an increase in the proportion of capillaries having a narrow, slit-like lumen (1.7±0.8% of controls; 7.1±1.9% at 1 week; 8.8±2.5% at 2 weeks; P〈0.02), some of which were smaller in size (less than 2 μm diameter) than in controls (3–5 μm) and/or “seamless”, i.e. lacking EC junctions. These may represent newly formed vessels. Focal discontinuity of the basement membrane and abluminal EC processes were rarely seen, and capillary growth by abluminal sprouting appeared to be very infrequent (less than 0.001% of profiles). Of more importance was growth starting from the luminal side. Significantly more thin cytoplasmic processes were observed protruding into the lumen of capillaries after 1 week (47.5±6.2%, P〈0.001) and 2 weeks of prazosin (34.2±5.5%, P〈0.05) than in control vessels (16.7±3.9%). Some of these traversed the entire lumen and connected with endothelium of the opposite side, probably involving membrane fusion, resulting in the appearance of a double lumen. Individual capillaries with a complete double lumen were observed after 2 weeks’ prazosin but comparatively rarely, in only four out of six muscles. These findings indicate a pattern of luminal growth which is completely different from intussusceptive growth previously described during development, and from the abluminal capillary sprouting seen under pathological circumstances.
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  • 80
    ISSN: 1573-9368
    Keywords: particle bombardment ; transgene expression ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A population of R0 transgenic wheat plants, generated by particle bombardment, was analyzed to define molecular, genetic and phenotypic properties resulting from transformation with a cointegrate vector, or cotransformation with two separate plasmids. By evaluating the progeny of 70 independently-derived transgenic plants, we also identified rare events such as chimerism and transgene elimination, which provide valuable information concerning the development of transgenic cereal plants following bombardment experiments. The frequency of chimerism in our transgenic wheat plants was very low. Furthermore, while transgene elimination did occur, this was also a very rare event. We determined the copy numbers of integrated transgenes and the levels of transgene expression. Comparisons to transgenic rice plants generated in the same manner demonstrated some similarities, but also important differences in transgene behavior. Whereas in rice there is no evidence for any direct relationship between transgene copy number and transgene expression or stability, multicopy populations in wheat demonstrated a bias towards higher levels of expression for the two genes and the maize ubiquitin promoter evaluated in the present study.
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  • 81
    ISSN: 1573-5028
    Keywords: calcium ; in situ hybridization ; multigene family ; polyploid ; signal transduction ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Recently, we reported on the characterization of the calmodulin (CaM) gene family in wheat [44]. We classified wheat CaM genes into four subfamilies (SFs) designated SF-1 to SF-4, each representing a series of homoeoallelic loci on the homoeologous chromosomes of the three genomes of common wheat. Here we studied the expression of these wheat CaM genes in the course of wheat development. Northern blot analysis using SF-specific probes revealed differences in SF expression levels in different organs and stages of development. Subsequently, cell-specific expression of CaM SFs was investigated by in situ RNA hybridization. In developing seeds, all CaM SFs showed highest expression in the embryo and less in the aleurone and in the starchy endosperm. In primary roots, all four CaM SFs were expressed in the root cap, meristematic regions and in differentiating cells. During development of the roots, expression gradually decreased. The wheat glutenin gene, which was used as a control throughout our experiments, was found to be expressed in the starchy endosperm but not in the aleurone, embryos or vegetative tissues. In stems, at advanced stages of growth, differences in cell-specific expression of CaM SFs were found. For example, SF-2 was highly expressed in differentiating phloem fibers. Thus, CaM genes in common wheat exhibit a developmentally regulated organ-, tissue-, cell- and SF-specific expression patterns.
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  • 82
    ISSN: 1615-6102
    Keywords: Cucumis sativus ; Ethylene ; Ferric-reducing capacity ; Iron deficiency ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Dicotyledonous plants respond to Fe deficiency by enhancing the capacity of their roots to reduce Fe(III) to Fe(II). It has been suggested that there are two different ferric redox systems in the roots: the standard reductase, active with ferricyanide and not inducible by Fe deficiency, and the turbo reductase, active with both ferricyanide and ferric chelates and inducible by Fe deficiency. We have used different experimental approaches to test whether or not the Fe(III)-reducing capacity of cucumber (Cucumis sativus L. cv. Ashley) roots can be explained by considering the standard and the turbo reductase as the same enzyme. For this, we used both Fe-sufficient and Fe-deficient plants, which were treated with ethylene inhibitors (cobalt or silver thiosulfate; found to inhibit the turbo reductase in a previous work), a protein synthesis inhibitor (cycloheximide), or an mRNA polyadenylation inhibitor (cordycepin). At different times after application of these inhibitors, reduction of both ferricyanide and Fe(III)-EDTA were determined. In addition, we studied the effects of pH and temperature on the reduction of ferricyanide and Fe(III)-EDTA by both Fe-sufficient and Fe-deficient plants. Results suggest that there are, at least, two different ferric redox systems in the roots. Enhancement of Fe(III)-reducing capacity (turbo reductase) by Fe-deficient plants probably requires the de novo synthesis of a (or several) protein(s), which has a high turnover rate and whose expression is presumably regulated by ethylene.
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  • 83
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    Annals of biomedical engineering 26 (1998), S. 526-533 
    ISSN: 1573-9686
    Keywords: Rat ; Artery: femoral ; Arterial diameter ; Vasomotion ; Shear stress ; Flow-dependent constriction ; Step flow ; Oscillating flow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract The effects of flow and flow changes on arterial diameter were investigated in vitro on isolated rat femoral arteries. Segments of femoral arteries were excised, mounted on microcannulas, and perfused with Tyrode's solution (37°C). Perfusion pressure was kept constant at 90 mm Hg. The mean external diameter after equilibration at a transmural pressure of 90 mm Hg was 720 ± 50 μ m (n=12). Vessels were then constricted with norepinephrine (1 μM in the superfusion solution) to 77% ± 13% of the resting diameter; acetylcholine was used to check endothelial function. The external diameter was measured continuously using video microscopy. The arteries were subjected to two different types of flow variations: (a) step changes in flow (increase and decrease, n=6) and (b) low-frequency sinusoidal flow variations (frequencies ranging from 0.002 to 0.1 Hz, n=11). Flow ranged from 0 to 800 μ l/min (shear stress ranging from 0 to 15 dyn/cm2). All measured vessels constricted as flow increased. Flow steps induced exponential-like contractions (flow increase) or relaxations (flow decrease) with mean characteristic time constants 31 ± 4 and 22 ± 2 s, respectively. Sinusoidal flow oscillations induced sinusoidal diameter oscillations with a time delay. An increase in the frequency of the flow led to a decrease of both the amplitude of the flow-induced diameter oscillations and the phase shift between flow and diameter. The dynamic diameter response to flow changes could be characterized by a first-order low-pass filter with a time constant of 22 s. © 1998 Biomedical Engineering Society. PAC98: 8745Hw
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  • 84
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    Euphytica 100 (1998), S. 189-196 
    ISSN: 1573-5060
    Keywords: cytoplasmic effects ; inheritance ; quality ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The inheritances of thousand kernel weight (TKW), protein percentage, protein quality and grain hardness were studied through an 11 x 11 complete diallel set of bread wheat genotypes consisting of four alloplasmic lines of Selkirk, two alloplasmic lines of Siete Cerros 66, and five commercial cultivars. Genetic components accounted for 93%, 90%, 78%, and 92% of total variation for TKW, protein percentage, protein quality, and grain hardness, respectively. General combining ability (GCA) effects were dominant for TKW (48% GCA, 38% SCA [specific combining ability], and 7% reciprocal effects [RE]), protein percentage (70% GCA, 10% SCA, and 10% RE), and grain hardness (59% GCA, 29% SCA, and 4% RE). However, SCA effects dominated for protein quality (30% GCA, 43% SCA, and 5% RE). Broad- and narrow-sense heritabilities were estimated at 0.95 and 0.65 for TKW, 0.94 and 0.82 for protein percentage, 0.83 and 0.47 for protein quality, and 0.95 and 0.74 for grain hardness. Reciprocal effects were highly significant for all quality traits, but less effective than additive and non-additive gene effects. Aegilops cylindrica, Ae. ventricosa, and Triticum turgidum cytoplasms showed positive effects on TKW in some crosses. Ae. cylindrica, Ae. variabilis, and Ae. uniaristata cytoplasms seemed to have potential for improving protein percentage. T. aestivum cytoplasms were superior to alien cytoplasms for protein quality. Bolal 2973, Kiraç 66 and Bezostaja 1 cytoplasms increased protein quality in some crosses. Ae. cylindrica, Ae. variabilis, Ae. ventricosa and Ae. uniaristata cytoplasms had significant effects on grain hardness. The cytoplasmic variation in B type T. aestivum cytoplasm was found to be significant for all traits.
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  • 85
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; combining ability ; heterosis ; genetic distance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In wheat, the possibility of introducing F1 seed into practical agriculture has been greatly enhanced by the discovery of effective chemical hybridising agents (CHAs). Although some technical and economic problems concerning the use of CHAs for large-scale production of F1 seed remain to be solved, a first group of F1 hybrids has been submitted for registration in several European countries i.e., France, England and Italy. Combining ability for grain yield and several agronomic and quality traits was studied in an eight-parent diallel cross. Highly significant combining ability effects were observed for all the traits while specific combining ability effects were statistically significant for grain yield, plant height, heading time and Chopin alveograph parameter P. The level of genetic diversity between parents as estimated using molecular markers is considered a tool for predicting the hybrid performance and heterosis of crosses. To explore this possibility, RFLP and RAPD markers were used to predict the performance of hybrids obtained from diallel and top crosses. The performance of the hybrids was determined in replicated plot trials sown at normal seed density in several locations. Coefficient of parentage (rp), based on pedigree information for all the pairwise combinations of the parents ranged from 0.01 to 0.34. The parents were assayed for random amplified polymorphic DNA (RAPD) with 87 primers which generated 304 polymorphic bands. Genetic similarity between parents, estimated on the basis of common bands using the Jaccard's similarity coefficient (J), ranged from 0.25 to 0.57. Correlation between parental diversity and hybrid performance was generally weak. A positive trend is observed in the yield potential of the hybrids produced in Italy in the last 10 years. In fact among the first set of hybrids produced by random crossing of the available cultivars, none produced 10% more than the checks whereas the last generation of hybrids includes combinations yielding 15% more than the best standards. Our results clearly indicate the need to develop specific strategies in order to identify and/or to select parental lines with a high level of general combining ability (GCA) and specific combining ability (SCA). The information regarding the genetic diversity of the parental lines do not appear helpful for predicting F1 performance.
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  • 86
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    Euphytica 101 (1998), S. 9-16 
    ISSN: 1573-5060
    Keywords: heading time ; Triticum aestivum ; vernalisation response ; Vrn – genotypes ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Substitution lines with reciprocal substitutions of chromosomes containing recessive alleles of the homoeologous group 5 chromosomeVrn genes between varieties of winter wheat with high vernalisation requirement (‘Mironovskaya 808’) and low vernalisation requirements (‘Bezostaya 1’) have been created. On this basis the genetic determination of vernalisation requirement was established. Substitution lines Mironovskaya 808 (Bezostaya 1 5A), Mironovskaya 808 (Bezostaya 1 5B), Mironovskaya 808 (Bezostaya 1 5D) and reciprocal substitution lines Bezostaya 1 (Mironovskaya 808 5A), Bezostaya 1 (Mironovskaya 808 5B) and Bezostaya 1 (Mironovskaya 808 5D) were grown under different durations of vernalisation (3, 4, 5, 6, 7 and 8 weeks) and their response was evaluated. Photoperiodic sensitivity of the original parental genotypes was also determined. Reciprocal substitution lines of the same chromosome that carries the same vrn allele responded differently to vernalisation deficit. Differences have been shown between all group 5 reciprocal substitutions. Lines carrying chromosomes 5A and 5D of Mironovskaya 808 had a high vernalisation requirement whereas lines carrying chromosome 5B of Bezostaya 1 (vrn2B) had a low vernalisation requirement. The reciprocal lines had a reverse requirement. This explains the different vernalisation requirements of the original varieties: Mironovskaya 808 with a high vernalisation requirement carries two alleles (vrn1M and vrn3M) in its genotype that increase the vernalisation requirement, whereas Bezostaya 1 with a lower requirement for vernalisation contains only one such allele (vrn2B). By combination of the alleles in the lines with the substitution of chromosome 5B carrying vrn2 allele that in both original genotypes work inversely to the other alleles, transgressive genotypes have been formed: genotype vrn1M vrn2B vrn3M determines a higher vernalisation requirement than original variety Mironovskaya 808, and genotype vrn1B vrn2M vrn3B determines a lower vernalisation requirement than the original Bezostaya 1. An incomplete vernalisation requirement prolonged the time to heading, with exponential dependence on the vernalisation deficit, or prevented heading altogether. The original varieties further differed in photoperiodic sensitivity (Mironovskaya 808 sensitive, Bezostaya 1 less sensitive) that also influenced the background of substitution lines. The impact of the background on the heading time showed itself by about one week difference between Mironovskaya 808 and Bezostaya 1 grown under 8 weeks vernalisation and normal photoperiod. The difference between the lines with Mironovskaya 808 background and the lines with Bezostaya 1 background was approximately the same and was not significantly changed in different vernalisation variants of the lines. This difference may be caused by different photoperiodic sensitivity of the original varieties, but also by other genes, such as genes of earliness per se.
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  • 87
    ISSN: 1573-5060
    Keywords: bread wheat ; Triticum aestivum ; tolerance to deoxynivalenol ; somaclonal variant ; in vitro selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This study was conducted to develop an efficient in vitro selection system for scab resistance by using in vitro screening for tolerance to deoxynivalenol (DON). Immature embryos of two wheat varieties, a scab-resistant variety Sumai 3 and a susceptible variety Mianyang 11, and their reciprocal F1 hybrids were cultured on MS medium supplemented with 2,4-D 2 mg/l and 0.6 × 10-4 M DON for callus induction. The responses of callus induction and plant regeneration to 0.6 × 10-4 M DON differed significantly between resistant and susceptible varieties, according to observed scab resistance levels at the plant level in the field. The percentage of callus formation of resistant variety Sumai 3 on induction medium containing DON was higher than that of susceptible variety Mianyang 11. Regeneration of DON-tolerant calli on DON-containing differentiation medium differed significantly between Sumai 3 and Mianyang 11. Averaged across the DON-tolerant calli of two varieties and their reciprocals, regeneration of DON-tolerant calli was decreased 3-fold on DON-containing medium. By an inoculation test with conidiospores of Fusarium graminearum Schw, we obtained several resistant lines from progenies of regenerated plants from DON-tolerant calli. These somaclonal lines had lower disease scoring (reaction index, infected spikelets and disease incidence), shorter plants and better yield components than Sumai 3, a famous Chinese resistant variety.
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  • 88
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; Secale cereale ; T1BL.1RS ; chromosome substitution and translocation ; yield components
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The T1BL.1RS wheat (Triticum aestivum L.) - rye (Secale cereale L.) translocations have been of particular interest and are widely used in bread wheat breeding programs. The objective of this study was to determine the effect of the T1BL.1RS chromosome on grain yield and its components using 20 near-isolines of spring bread wheat cultivar ‘Seri M82’ (10 homozygous for chromosome 1B substitution and 10 homozygous for T1BL.1RS). The test lines have been produced by substituting the 1B chromosome in Seri M82 (T1BL.1RS, T1BL.1RS) through backrossing. Two field experiments were evaluated under optimum (five irrigations) and reduced (one irrigation) moisture conditions for two consecutive production cycles at the Mexican National Agricultural Research Institute, Ciudad Obregon, Sonora, Mexico. The presence of T1BL.1RS had a significant effect on grain yield, harvest index, grains/m2, grains/spike, 1000-grain weight, test weight, flowering date and physiological maturity in both moisture conditions. The agronomic advantage of the 1B substitution lines on above-ground biomass yield at maturity, spikes/m2and grain-filling duration was expressed only under the optimum moisture condition. The presence of T1BL.1RS increased grain yield 1.6% and 11.3% for optimum and reduced moisture conditions, respectively. These results encourage further use of T1BL.1RS wheats in improving agronomic traits, especially for reduced irrigation or rainfed environments.
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  • 89
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    Euphytica 104 (1998), S. 39-47 
    ISSN: 1573-5060
    Keywords: drought resistance ; diallel graph ; gene action ; excised-leaf water loss ; relative water content ; bread wheat ; osmotic adjustment ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Little information is available on the genetics of excised leaf water loss and relative water content in wheat. An experiment conducted on the F1 generation from a half-diallel set of crosses involving two drought tolerant, two moderately tolerant and two sensitive varieties was initiated to investigate the inheritance of excised-leaf water loss and relative water content. This experiment was conducted under glass-house and field conditions at tillering and anthesis stages of plant development. Additive gene action, in general, played a major role in determining the inheritance of these traits. General combining ability (GCA) was the main source of genetic variation among crosses, while specific combining ability (SCA) was negligible. Strong phenotypic correlations existed between per se performance and GCA effects in the majority of cases. Heterosis was unimportant. Genotype-environmental interactions and/or differential gene expression appeared to account for different results found between environments and growth stages, respectively. Selection for relative water content appeared to be more effective at anthesis, while for excised-leaf water loss at both stages of plant growth. In addition to drought resistance, wide differences for morphological characters and relative positions of parental arrays revealed the possibility of obtaining desirable segregants for drought stress conditions from the cross Kharchia 65 × WH 147.
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  • 90
    ISSN: 1573-5036
    Keywords: biomarker ; cadmium ; copper ; heavy metal ; PC ; PC-SH ; phytochelatin ; stress ; toxicity ; Triticum aestivum ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Heavy metal contaminated soils often show increased levels of more than one metal, e.g. copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb) or nickel (Ni). In case such soils are used for crop production, prediction of yield reduction or quality decline due to heavy metals in the soil is inadequate when based only on chemical soil analysis. The use of biomarkers such as phytochelatins (PC), non-protein thiols specifically induced in plants upon exposure to heavy metals, may be an additional tool or diagnostic criterion in heavy metal research and in practice. In the present work, Cu and Cd uptake and induction of PC synthesis are studied with hydroponically grown maize and wheat plants exposed to mixtures of the two metals. We observed a close positive relationship between the concentrations of Cd and PC in the plant shoot material. A decreased shoot concentration of Cd after addition of Cu, due to metal competition at common root absorption sites, coincided with lower shoot PC levels. Also differences in metal uptake and xylary metal transport among the two plant species were reflected in corresponding differences in PC concentration. The observed direct relationship between shoot PC concentration and the degree of metal-induced growth inhibition makes the use of PC promising for the purpose tested for.
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  • 91
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; Puccinia recondita ; leaf rust ; breeding ; resistance ; yield ; yield components
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The most important breeding objectives in crop improvement are improving grain yield, grain quality, and resistances to various biotic and abiotic stresses. The objectives of our study were to compare two crossing and four selection schemes for grain yield, yield traits, and slow rusting resistance to leaf rust (Puccinia recondita) based on additive genes in wheat (Triticum aestivum), and to identify the most efficient crossing and selection methodologies in terms of genetic gains and cost efficiency. Segregating populations were derived from 18 simple crosses and the same number of top (three-way) crosses. Half of the crosses were derived from Yecora 70 and the other half from Veery #10 as the common leaf rust susceptible parents. The four selection schemes were: pedigree, modified bulk (F2 and F1-top as pedigree, selected lines in F3, F4, F2-top, F3-top as bulk; and pedigree in F5 and F4-top populations), selected bulk (selected plants in F2, F3, F4, F1-top, F2-top and F3-top as bulk; and pedigree in F5 and F4-top populations), and nonselected bulk (bulk in F2, F3, F4, F1-top, F2-top and F3-top; and pedigree in F5 and F4-top populations). A total of 320 progeny lines, parents and checks were tested for grain yield, other agronomic traits and leaf rust resistance during the 1992/93 and 1993/94 seasons in Ciudad Obregon (Sonora State, Mexico) which represents a typical high yielding irrigated site. The influence of the type of cross and the selection scheme on the mean grain yield and other traits of the progenies was minimal. The selection of parents was the most important feature in imparting yield potential and other favourable agronomic traits. Moreover, the highest yielding lines were distributed equally. Progeny lines derived from Veery #10 crosses had significantly higher mean grain yield compared to those derived from the Yecora 70 crosses. Furthermore, a large proportion of the highest yielding lines also originated from Veery #10 crosses. Mean leaf rust severity of the top cross progenies was lower than that of the simple cross progenies possibly because two parents contributed resistance to top cross progenies. Mean leaf rust severity of the nonselected bulk derivatives was twice that of lines derived from the other three schemes. Selected bulk appears to be the most attractive selection scheme in terms of genetic gains and cost efficiency.
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  • 92
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    Euphytica 100 (1998), S. 253-259 
    ISSN: 1573-5060
    Keywords: hexaploid wheat ; pearl millett ; Pennisetum glaucum ; polyhaploid ; pollen storage ; Triticum aestivum ; wide crosses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of drying and freezing on viability of pearl millet pollen were examined with the aim of using stored pollen in polyhaploid production of hexaploid wheat. Freshly collected pollen of pearl millet line NEC 7006 with 55% water content, germinated at a frequency of 80%. Pollen that was dried for two hours to 6% water content showed 50% germination frequency and maintained similar frequencies after the freezing process. In crosses of hexaploid wheat variety Norin 61 with fresh pearl millet pollen, embryos were obtained at a frequency of 27.6%. In crosses with pollen stored at -196 °C, -80 °C and -20 °C for one month, embryo formation frequencies ranged from 27.5 to 17.4%. After five and twelve months of storage, the frequencies ranged from 29.7 to 14.6% at storage temperatures of -196 °C and -80 °C, and from 8.0 to 3.2% at -20 °C, indicating significant differences among storage temperatures. However, no significant frequency difference was found among pollen water contents at the time of collection. All plants regenerated from crosses with pearl millet pollen stored for five months were wheat polyhaploids. These results suggest that stored pearl millet pollen is an efficient medium for producing polyhaploids in hexaploid wheat.
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  • 93
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    Euphytica 100 (1998), S. 305-311 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; winter wheat ; genetic diversity ; ancestors ; genetic profile
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract With the aid of GRIS, the wheat genetic resources database, the retrospective analysis of winter wheat breeding programs in the ex-USSR during its existence, and modern Russia, was conducted. The dynamics of genetic diversity of released cultivars was studied. A significant tendency to reduce the use of local materials was discovered, although a stable set of original ancestors has prevailed over the last 40 years. The modern cultivar genes pool has increased as a result of the utilisation of North American semidwarf varieties. Breeding programs at different breeding centres are distinguished by varying levels of genetic diversity. The need to discover new sources of disease resistance and environmental adaptation are problems that remain.
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  • 94
    ISSN: 1573-5060
    Keywords: in situ hybridization ; Psathyrostachys juncea ; chromosome translocation ; translocation addition ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Using the genomic in situ hybridization (GISH) technique, one translocation line, seven translocation-addition lines, five translocation plus translocation addition lines and two ditelosomic addition lines were identified in backcross progenies of Triticum aestivum L. -Psathyrostachys juncea (Fisch.) Nevski intergeneric hybrids. No complete P. juncea chromosomes were detected in the 25 lines studied. The results suggest that intact P. juncea chromosomes may be difficult to isolate in a wheat background.
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  • 95
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    Methods in cell science 20 (1998), S. 203-207 
    ISSN: 1573-0603
    Keywords: Endocarditis ; Rat ; Streptococci
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The rat model of endocarditis is a well established experimental protocol which closely approximates human native valve endocarditis. The rat model of endocarditis has been used to examine the role of particular streptococcal virulence factors, to assess immunoprotective strategies, and to evaluate the efficacy of selected antibiotic treatment regimens for streptococcal endocarditis. Like humans, rats are generally susceptible to endocarditis only if the cardiac valves have been damaged. In the rat model of endocarditis, damage to the aortic valve and sterile vegetation formation is accomplished by insertion of a polyethylene catheter through the carotid artery into the left ventricle. Following catheter insertion, an inoculum of streptococci are injected intravenously. Vegetations removed from the heart valves during thoracotomy of euthanized animals are qualitatively cultured for streptococcal infection. The method, including investigator safety considerations, is described in detail.
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  • 96
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; Heterodera avenae ; resistance ; breeding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Breeding wheat for resistance to Heterodera avenae in southern Australia has been in progress for nearly 30 years and recently a number of resistant varieties have been released. Early breeding work was hampered by three factors: • a lack of appreciation of the role and extent of the problem, • inaccurate, slow screening methods, ultimately being replaced by the 'tube' test and soon by linked molecular markers, • inappropriate breeding strategies, so that varietal releases have taken place only when the breeding has been fully integrated into the main programs. The experiences in southern Australia will be relevant to many other areas in the world where H. avenae is the major pest.
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  • 97
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    Euphytica 100 (1998), S. 131-135 
    ISSN: 1573-5060
    Keywords: boron ; tolerance ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A new method for screening wheat for boron tolerance has been developed to overcome the problems of methods used in the past. Seedlings were grown for 10 days while suspended over B-rich solutions. Their root lengths were then measured as an index of tolerance. Five varieties of wheat were screened at seven concentrations of B. Results were obtained more quickly and easily than from the alternative methodologies and compared favourably. Screening of 128 doubled haploid lines from a cross between Halberd and (Wl*MMC) suggested that transgressive segregation had occurred.
    Type of Medium: Electronic Resource
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  • 98
    ISSN: 1573-5060
    Keywords: leaf rust ; Puccinia recondita f. sp. tritici ; resistance genes ; Triticum aestivum ; Triticum monococcum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Monosomic analysis was conducted to determine chromosomal locations of three new leaf rust resistance genes recently transferred to common wheat (Triticum aestivum) from T. monococcum. The resistance gene in wheat germplasm line KS92WGRC23 was transferred from T. monococcum ssp. monococcum. The resistance genes found in KS93U3 and KS96WGRC34 were transferred from T. monococcum ssp. aegilopoides. Allelism tests showed that the three resistance genes were unlinked. The three lines were crossed with each of the seven A-genome Wichita monosomic lines. The leaf rust resistance genes in KS92WGRC23, KS93U3, and KS96WGRC34 were located on chromosomes 6A, 1A, and 5A, respectively, by monosomic analysis. These results demonstrate that the three new genes derived from T. monococcum are each different. They also differ from previously reported Lr genes. This information on chromosome location and the development of mapping populations will facilitate molecular tagging of the new genes.
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  • 99
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 102 (1998), S. 219-226 
    ISSN: 1573-5060
    Keywords: antifreeze proteins ; chromosome substitution lines ; cold acclimation ; freezing tolerance ; Triticum aestivum ; winter survival
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Antifreeze proteins (AFPs) accumulate in the leaves of winter cereals during cold acclimation, where they may inhibit ice recrystallization during freezing and thawing cycles and provide nonspecific disease resistance. In this study, 21 wheat chromosome substitution lines and the parental lines Chinese Spring and Cheyenne wheat were used to determine the heritability of AFPs and the relationship between the accumulation of AFPs and winter survival. In cold-acclimated lines, antifreeze activity in leaf apoplastic extracts ranged from 1 (low) to 5 (high) with an average value of 3.2, and the accumulation of apoplastic proteins ranged from 30 μg (g FW)-1 to 115 μg (g FW)-1 with a mean value of 70 μ (g FW)-1. Examination of the individual lines revealed that Cheyenne chromosomes 5B and 5D carry major regulatory genes that increase both antifreeze activity and the accumulation of antifreeze proteins in plants grown at low temperature. Substitution lines carrying Cheyenne chromosomes 2A, 3A, 6B, and 7A exhibited lower freezing tolerance and also showed a marked decrease in the accumulation of specific AFPs during cold acclimation. Antifreeze activity and apoplastic protein content were not correlated with freezing tolerance (defined as % survival at -11 °C), but they were both significantly and positively correlated with winter field survival rates. Antifreeze activity (positively correlated) and total leaf fresh weight (negatively correlated) together accounted for about 55% of the variation in winter survival, indicating that high antifreeze activity and slow vegetative growth at low temperature are both important quantitative traits for winter survival.
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  • 100
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 100 (1998), S. 359-369 
    ISSN: 1573-5060
    Keywords: genetics ; intrinsic earliness ; photoperiodic response ; vernalisation requirement ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Genetic systems regulating bread wheat ontogenesis have been studied at Ukraine's Plant Breeding and Genetics Institute, for more than two decades. The influence of Vrn genes is the most obvious; dominant alleles of Vrn genes inhibit the vernalisation requirement. The Vrn genotypes of more than 1000 cultivars were determined and the peculiarities of gene geography were shown. Dominant Vrn1 or Vrn2 seemed to be replaced by Vrn3 in regions closer to the equator. In the developed sets of near-isogenic (congenic) lines, the value of different genes was characterised for certain environments (favourable – phytotron, natural – early or late drought) based on their effects. Methods of Vrn gene manipulation were elaborated, including methods for winter genotype selection from spring x spring crosses. The possibility of alien homoeologous Vrn loci introgression was shown. In the introgressed lines, the new genes were identified and found to be nonallelic to known Vrn genes in wheat. In studying congenic lines for three Ppd genes, differences were observed in duration and intensity of photoperiodic response, vernalisation requirement and effects on agronomic traits. For typical winter wheats, two loci were identified that influenced the duration of the vernalisation requirement. One system, controlling intrinsic earliness, might be responsible for the differences in reaction to light intensity, as selection of earlier genotypes is supposed to be more effective at lower light intensity.
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