Classification of German white wines with certified brand of origin by multielement quantitation and pattern recognition techniques

A procedure is proposed for the determination of the authenticity of white wines from four German wine-growing regions (Baden, Rheingau, Rheinhessen, and Pfalz) based on their content of some major, trace, and ultratrace elements. One hundred and twenty-seven white wine samples possessing a certificate of origin, all of the 2000 vintage, were analyzed. The concentrations of 13 elements (Li, B, Mg, Ca, V, Mn, Co, Fe, Zn, Rb, Sr, Cs, and Pb) were determined in wine diluted 1:20 by sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). Indium was routinely used as internal standard. Supervised pattern recognition techniques such as discriminant analysis and classification trees were applied for the interpretation of the data. A quadratic discriminant analysis (QDA) allowed the four regions to be discriminated with 83% accuracy when using only eight variables (Li, B, Mg, Fe, Zn, Sr, Cs, and Pb), and the prediction ability for classifying new samples was 76%. By use of a second method, a decision tree, the classification of samples coming from the four regions could be performed with an accuracy of 84% when only four elements were used: Li (very low in samples from Baden), Zn (abnormally low in the samples from the Rheingau), and Mg and Sr (both important for the differentiation between Pfalz and Rheinhessen samples). For this method, the prediction ability was only 74% in the identification of unknown samples. The robustness of the QDA model was not good enough, and therefore the tree is better recommended for the classification of new wine samples from these areas of German wine production.     

The occurrence of terrestrial algae on two beech sites on a Cambisol

The occurrence of terrestrial algae on two beech sites was determined qualitatively and quantitatively in the litter, organic and mineral layer. Both sites are beech stands of different age and the soil type is a Cambisol. On the site with young beech the maximal value determined was 1.0 · 10⁸ algae g^?1 dw in the litter layer. With increasing soil depth the number of algae decreased on both sites, and at the young beech stand site no algae were found in the mineral soil. Chlorophyceae were the dominant algae group and at the young beech stand Bacillariophyceae were present.     

Krankheiten und Schädlinge in Acker- und Feldgemüsebau

Ohne Zusammenfassung     

Phytopathologische Lehrausflüge

Ohne Zusammenfassung     

Element content and pH value in American black cherry (<Emphasis Type="Italic">Prunus serotina</Emphasis>) with regard to colour changes during heartwood formation and hot water treatment

Element content and pH value in wood tissues of veneer grade logs of P. serotina Ehrh. were investigated with regard to wood colour variations, measured in the CIEL*a*b* system. The average pH value of heartwood tissue was about pH 4.0 and medium colour parameters of veneer sheets were determined at L* = 73, a* = 9.8, and b* = 23.5. Optical emission spectroscopy (ICP-OES) analyses showed differences in the element contents between two regional forest sites coming from Pennsylvania and West Virginia, USA, respectively. The latter is mainly characterised by higher variations of micro-element content in the transition zone (influencing heartwood formation) and also pH value of wood tissue, which contributes to higher variations in colour response of industrially produced veneer sheets. Investigations under industrial conditions underline the correlation between length and intensity of heat treatment in veneer production and colour development: with increasing duration and temperature of hot water treatment, veneer surfaces become darker and wood colour is intensified (ΔL = 3.6, Δa = 2.1, comparing 12 and 72 h of hot water treatment at 60°C). However, no equalisation of wood colour was achieved by modifying the treatment conditions. Artificial radiation by UV–visible light, quickly and extensively darkens and intensifies wood colour (ΔL = 16, Δa = 3.5, and Δb = 4.0 after 15 h of artificial radiation), but variations in wood colour deriving from different treatment conditions during veneer production, were not reduced.     

Aneuploids as a key for new molecular cloning strategies: development of DNA markers by microdissection using Triticum aestivum-Aegilops markgrafii chromosome addition line B

Summary We established a chromosome specific DNA library of the Aegilops markgrafii chromosome B. Eight microdissected chromosomes B obtained from a monosomic T. aestivum-Aegilops markgrafii addition line were PCR-amplified and the DNA was cloned in Escherichia coli DH5. Clones were characterized by dot blot hybridization with total Ae. markgrafii DNA. 62% of clones represented repetitive sequences and 38% low or single copy sequences. The estimated length of excised inserts varied between less than 200 bp and more than 500 bp. The average size of inserts was 310 bp.Abbreviations bp base pairs - DOP-PCR degenerated oligonucleotide primed polymerase chain reaction