Competition Effects Among Isolates of Fusarium culmorum Differing in Aggressiveness and Mycotoxin Production on Heads of Winter Rye     

Thomas Miedaner  Angela G. Schilling  Geiger 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(1):63-70

Fusarium culmorum is a phytopathogenic, toxigenic fungus causing seedling diseases, foot rot and head blight of cereals. For estimating competition effects in mixtures of two single-spore isolates, two winter rye single crosses were tested with either four isolates individually or four 1 : 1 mixtures of the same isolates in six field environments. Two isolates (FC46, FC64) were highly aggressive deoxynivalenol (DON) and 3-acetyl DON-producers, the other two (FC30, FC71) were medium aggressive nivalenol-producers. Rye heads were inoculated during flowering with conidia of pairs of isolates expressing similar (FC46 + FC64, FC30 + FC71) or contrary (FC46 + FC71, FC30 + FC64) levels of aggressiveness and similar or different concentrations and chemotypes of mycotoxins, respectively. Head blight rating and yield components relative to the non-inoculated plots were recorded as aggressiveness traits. Additionally, mycotoxin concentrations were measured in the rye grain. Random pathogen samples were re-isolated from heads at the onset of symptom development and analysed by molecular markers (RAPD–PCR) in one environment. Aggressiveness of the isolate mixtures was significantly lower than that of the isolates applied individually on both rye genotypes. Similarly, mycotoxin concentrations were significantly lower in the mixtures in seven out of eleven comparisons. Among the re-isolates, the component genotypes of a mixture significantly deviated from the inoculated 1 : 1 ratio when a particular isolate (FC46) was present in the mixture. This isolate displayed a superior competitive ability irrespective of the aggressiveness or mycotoxin profile of the mixing partner illustrating that pathogenic fitness is caused by additional factors that have not, as yet, been identified.  相似文献   

Gamma ray bursts. Cosmic mystery objects start to yield secrets     

Schilling G 《Science (New York, N.Y.)》2001,294(5548):1816-1817

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Astronomy. Weird new exoplanets leave theory behind     

Schilling G 《Science (New York, N.Y.)》2001,291(5503):409-412

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Astronomy. Pulsars solve mystery of missing gas     

Schilling G 《Science (New York, N.Y.)》2001,294(5542):497

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Wirkungen einer Androgen-Oestrogen-Kombination mit Depotcharakter auf die Fortpflanzungsfunktionen beim weiblichen Schwein     

W. Jöchle    E. Schilling    D. Smidt  und E. Fiedler 《Reproduction in domestic animals》1967,2(3):122-127

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Astronomy. Europe's telescope builders aim high     

Schilling G 《Science (New York, N.Y.)》2002,298(5602):2311

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Magnetic polarity of pillow basalts from reykjanes ridge     

De Boer J  Schilling JG  Krause DC 《Science (New York, N.Y.)》1969,166(3908):996-998

A first attempt to measure directly the magnetic polarity of submarine basalts dredged from the Reykjanes Ridge indicates that the first two magnetic anomalies over the ridge resulted from a reversal of the earth's magnetic field. Volcanic criteria were used to determine the orientation the samples had before they were dredged from the sea floor.  相似文献   

Polar orientation of dyes in robust multilayers by zirconium phosphate-phosphonate interlayers     

Katz HE  Scheller G  Putvinski TM  Schilling ML  Wilson WL  Chidsey CE 《Science (New York, N.Y.)》1991,254(5037):1485-1487

Polar orientation of molecules in solids leads to materials with potentially useful properties such as nonlinear optical and electrooptical activity, electrochromism, and pyroelectricity. A simple self-assembly procedure for preparing such materials is introduced that yields multiple polar dye monolayers on solid surfaces joined by zirconium phosphate-phosphonate interlayers. Second harmonic generation (SHG) shows that the multilayers have polar order that does not decrease with increasing numbers (up to a large number) of monolayers in the film. The inorganic interlayers, as determined by SHG, impart excellent orientational stability to the dye molecules, with the onset of orientational randomization above 150 degrees C.  相似文献   

Evolution of the ratio of strontium-87 to strontium-86 in seawater from cretaceous to present     

Hess J  Bender ML  Schilling JG 《Science (New York, N.Y.)》1986,231(4741):979-984

A detailed record of the strontium-87 to strontium-86 ratio in seawater during the last 100 million years was determined by measuring this ratio in 137 well-preserved and well-dated fossil foraminifera samples. Sample preservation was evaluated from scanning electron microscopy studies, measured strontium-calcium ratios, and pore water strontium isotope ratios. The evolution of the strontium isotopic ratio in seawater offers a means to evaluate long-term changes in the global strontium isotope mass balance. Results show that the marine strontium isotope composition can be used for correlating and dating well-preserved authigenic marine sediments throughout much of the Cenozoic to a precision of +/-1 million years. The strontium-87 to strontium-86 ratio in seawater increased sharply across the Cretaceous/Tertiary boundary, but this feature is not readily explained as strontium input from a bolide impact on land.  相似文献   

Microbial activity and bacterial composition of H₂-treated soils with net CO₂ fixation     

Susanne Stein  Rolf Schilling  Michael Schmid 《Soil biology & biochemistry》2005,37(10):1938-1945

The effects of H₂ gas treatment of an agricultural soil cultivated previously with a mixture of clover (Trifolium pratense) and alfalfa (Medicago sativa) on CO₂ dynamics and microbial activity and composition were analyzed. The H₂ emission rate of 250 nmol H₂ g⁻¹ soil h⁻¹ was similar to the upper limit of estimated H₂ amounts emitted from N₂ fixing nodules into the surrounding soil ([Dong, Z., Layzell, D.B., 2001. H₂ oxidation, O₂ uptake and CO₂ fixation in hydrogen treated soil. Plant and Soil 229, 1-12.]). After 1 week of H₂ supply to soil samples simultaneously with H₂ uptake net CO₂ production declined continuously and this finally led to a net CO₂ fixation rate in the H₂-treated soil of 8 nmol CO₂ g⁻¹ soil h⁻¹. The time course of H₂ uptake and CO₂ fixation in the soils corresponded with an increase in microbial activity and biomass of the H₂-treated soil determined by microcalorimetric measurements, fluorescence in situ hybridization analysis (FISH) and DNA staining (DAPI). Shifts in the bacterial community structure caused by the supply of H₂ were recorded. While the H₂ treatment stimulated β-and γ-subclasses of Proteobacteria, it had no significant effect on α-Proteobacteria. In addition, FISH-detectable bacteria of the Cytophaga-Flavobacterium-Bacteroides phylum increased in numbers.  相似文献