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Many Fusarium head blight (FHB) [caused by Fusarium graminearum Schw. and F. culmorum (W.G. Sm.) Sacc.] quantitative trait loci (QTL) have been detected in both spring and winter wheat (Triticum aestivum L.). However, a QTL validation has not been performed in winter wheat. We report on the verification of resistance QTL in winter wheat, which had been previously mapped in a Dream/Lynx population. The QTL intervals of chromosomes 7BS, 6AL, and 2BL were enriched with amplified fragment length polymorphism (AFLP) markers. For a more precise estimation of the QTL effects and their influence on plant height and heading date, BC2F4 lines were created by marker-assisted selection and examined for FHB resistance. The phenotypic effects of the two main QTL on chromosomes 6AL and 7BS confirmed the previous results of the original mapping population. In the backcross population, QTL6AL and QTL7BS reduced FHB severity individually by 27% each relative to lines without resistance alleles. Both QTL had an effect on plant height, resulting in taller plants being more resistant. The combination of both QTL decreased disease severity most effectively (36%). The successfully validated QTL on chromosomes 6AL and 7BS are designated QTL6AL and QTL7BS, respectively. The best genotypes carried one or both of the major QTL, displaying their importance for disease resistance. In contrast to spring wheat, where QTL have been identified in an exotic genetic background, the resistance QTL validated in this study already reside in an adapted genetic background with excellent agronomic performance. [ABSTRACT FROM AUTHOR]

Multielement isotope ratio analysis was checked for its suitability as a means for the discrimination between agricultural products from integrated/conventional or organic production, respectively. Differences were mainly found for δ 15 N-values. Paprika and tomatoes from organic production in greenhouses showed δ 15 N-values above+7 ‰, whereas corresponding products from conventional cultivation had δ 15 N-values near 0 ‰. Lettuce, onions, cabbage and Chinese cabbage from field production had δ 15 N-values in the range of+5 to+6 and+5.5 to+7.5 ‰, respectively (conventional and organic production); these overlapping differences do not permit a reliable discrimination. The same is true for wheat, showing average δ 15 N-values of+2.3±1.0 and+3.6±1.6 ‰, respectively. The unexpected relative high 15 N-enrichments of vegetables from integrated production are discussed as originating, at least partially, from 15 N-enrichment in the soil by NH 3 evaporation and denitrification. [ABSTRACT FROM AUTHOR]