Sulphur amino acid content and nutritive value of pea and cauliflower crude protein as influenced by Sulphur deficiency

Cystine concentrations (g/16g N) in plant tissue declined more under S deficiency conditions than methionine. In N-balance trials with rats the negative effect of S deficiency on S amino acid composition of peas and cauliflower resulted in a corresponding decrease of the biological value of the protein.     

Formation of 5-methyl-4-hydroxy-3[2H]-furanone in cytosolic extracts obtained from Zygosaccharomyces rouxii

Formation of the flavor compound and precursor 4-hydroxy-5-methyl-3[2H]-furanone (HMF, norfuraneol) was demonstrated in cytosolic protein extracts obtained from Zygosaccharomyces rouxii after incubation with a number of carbohydrate phosphates. 4-Hydroxy-5-methyl-3[2H]-furanone was produced from d-fructose-1,6-diphosphate, d-fructose-6-phosphate, d-glucose-6-phosphate, 6-phosphogluconate, d-ribose-5-phosphate, and d-ribulose-1,5-diphosphate. Enzyme assays revealed d-fructose-1,6-diphosphatase, phosphohexose isomerase, d-glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase activity in the cytosolic extracts. Model studies showed the spontaneous formation of HMF from d-ribulose-5-phosphate. It is assumed that d-ribulose-5-phosphate is generated in cytosolic extracts by the action of the investigated enzymes from the carbohydrate phosphates and is then chemically transformed to HMF. The hypothesis was proven by the production of HMF in solutions containing commercially available enzymes and [6-(13)C]-d-glucose-6-phosphate.     

Quantitative trait loci for adult-plant resistance to Mycosphaerella graminicola in two winter wheat populations

Septoria tritici blotch (STB) is one of the most important leaf spot diseases in wheat worldwide. The goal of this study was to detect chromosomal regions for adult-plant resistance in large winter wheat populations to STB. Inoculation by two isolates with virulence to Stb6 and Stb15, both present in the parents, was performed and STB severity was visually scored plotwise as percent coverage of flag leaves with pycnidia-bearing lesions. 'Florett'/'Biscay' and 'Tuareg'/'Biscay', each comprising a cross of a resistant and a susceptible cultivar, with population sizes of 316 and 269 F(7:8) recombinant inbred lines, respectively, were phenotyped across four and five environments and mapped with amplified fragment length polymorphism, diversity array technology, and simple sequence repeat markers covering polymorphic regions of ≈1,340 centimorgans. Phenotypic data revealed significant (P < 0.01) genotypic differentiation for STB, heading date, and plant height. Entry-mean heritabilities (h(2)) for STB were 0.73 for 'Florett'/'Biscay' and 0.38 for 'Tuareg'/'Biscay'. All correlations between STB and heading date as well as between STB and plant height were low (r = -0.13 to -0.20). In quantitative trait loci (QTL) analysis, nine and six QTL were found for STB ratings explaining, together, 55 and 51% of phenotypic variation in 'Florett'/'Biscay' and 'Tuareg'/'Biscay', respectively. Genotype-environment and QTL-environment interactions had a large impact. Two major QTL were detected consistently across environments on chromosomes 3B and 6D from 'Florett' and chromosomes 4B and 6B from 'Tuareg', each explaining 12 to 17% of normalized adjusted phenotypic variance. These results indicate that adult-plant resistance to STB in both mapping populations was of a quantitative nature.     

3-Hydroxy-4,5-dimethyl-2(5H)-furanone (Sotolon) causing an off-flavor: elucidation of its formation pathways during storage of citrus soft drinks.

Gas chromatography/olfactometry (GCO) and gas chromatography-mass spectrometry (HRGC-MS) revealed 3-hydroxy-4, 5-dimethyl-2(5H)-furanone (sotolon) to be responsible for the "burnt" and "spicy" off-flavor observed in citrus soft drinks during storage. Among the ingredients of citrus soft drinks, ethanol and ascorbic acid were identified as the essential precursors of sotolon. Two formation pathways were postulated by studies using (2)H (D)- and (13)C-labeled ethanol and ascorbic acid; i.e., sotolon is formed from two molecules of ethanol and carbons 2 and 3 of ascorbic acid (pathway 1), or it is generated from one molecule of ethanol and carbons 3-6 of ascorbic acid (pathway 2).     

Systemic cytokine profile in feeder pigs suffering from natural postweaning multisystemic wasting syndrome (PMWS) as determined by semiquantitative RT-PCR and flow cytometric intracellular cytokine detection

Postweaning multisystemic wasting syndrome (PMWS) is an economically important disease in pigs caused by porcine circovirus type 2 (PCV2). Development of this disease is presumably associated with an impairment of the immune system. We, therefore, investigated the systemic expression of relevant cytokines (IL-1, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p40, TNF-alpha, IFN-gamma) and IL-2Ralpha at mRNA (semiquantitative RT-PCR) and at protein level (flow cytometric intracellular cytokine detection after short-time stimulation of peripheral blood mononuclear cells) in 10 feeder pigs aged 14 weeks suffering from natural PMWS and in 10 clinically healthy pen-mates. Hematological examination revealed a significant (p < 0.001) relative lymphopenia in the diseased animals when compared to reference pigs. IL-1alpha and IL-10 mRNA levels were notably increased in the affected pigs, whereas IL-2 and IL-2Ralpha (CD25) mRNA levels tended to be down-regulated. IL-8, TNF-alpha and IFN-gamma mRNA expressions appeared to be slightly increased. Intracellular cytokine levels as measured by flow cytometry revealed an increase of IL-1beta, IL-2, and IL-6, whereas IL-12 and TNF-alpha expressions were not affected. IFN-gamma was slightly decreased in the diseased animals. In conclusion, despite the assumption, that the cellular immune response to PMWS as a virus-induced disease should be characterized by either a Th1 driven cytokine profile or a cytokine profile indicative of T cell immunosuppression, our results did not support that hypothesis. Nevertheless, data from intracellular cytokine detection suggest an even increased percentage of the remaining lymphocytes capable to produce IL-2 upon in vitro stimulation, which is in contrast to the slightly diminished IL-2 mRNA levels reflecting the in vivo situation at least at the mRNA level.     

Population genetics in forensic DNA typing.

Variable number of tandem repeat (VNTR) sequences are used to link defendants with crimes by matching DNA patterns. The probative value of a match is often calculated by multiplying together the estimated frequencies with which each particular VNTR pattern occurs in a reference database. However, this method is liable to potentially serious errors because ethnic subgroups within major racial categories exhibit genetic differences that are maintained by endogamy. The multiplication procedure currently in use can be made scientifically valid only by extensive sampling of VNTR frequency distributions in a variety of ethnic groups, similar to the ethnic studies of various blood groups done in the past. Alternative approaches for dealing with subpopulation heterogeneity are discussed.     

Ertragssimulation mit “Ceres Wheat” an Grundwasserböden gemäßigter Klimazonen. Teil 2: Verifizierung des geänderten Modelles “Ceres Wheat”

Calibration of the simulation model “Ceres Wheat” under conditions of soils with shallow watertable and temperate climate. Part 2: Verification of the modified model “Ceres Wheat” The Ceres Wheat yield model has been adopted to soils under wet conditions and to humide climate. The basic assumptions of the modified model have been checked. The simulated results of the soil water balance, the plant development and the nitrate losses by drain discharge give fairly well agreements to field data from a Calcaric Fluvisol (Speicherkoog, Schleswig-Holstein). The modification improves the model and leads to the opportunity to simulate special aspects in agronomical and ecological advices.     

The derivation of grassland vegetation types on the basis of site and land use characteristics

This study derives grassland communities from site, climate and land use characteristics, allowing yield estimation within the framework of model scenarios. Based on the dominant species, about 450 relevés, primarily of extensively used grassland from four regions of the North-East German lowlands, were classified into vegetation types using a cluster analysis. These types were then reclassified to known phytosociological communities. The relationship between the vegetational composition and the abiotic explanatory variables were verified by a discriminant analysis. The water supply level proved to be the most important factor influencing grassland vegetation. The impact of historical land use (especially the persistence of formerly sown species) reduced prognostic quality.