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Key message A novel approach based on the loaf volume–grain protein content relation is suggested to consider the static protein use efficiency and stability as efficient quality-related descriptors for wheat varieties. Abstract The most important trait for baking quality of winter wheat is loaf volume (V). It is mostly determined by grain protein content (GPC) and quality. New varieties with a high potential of grain protein use efficiency (ProtUE) are very important for reducing the surplus use of nitrogen fertilizer in areas where nitrogen leaching is large. This is also an important goal of agricultural policies in the European Union. Additionally, ProtUE needs to be very stable across environments in the face of progressing climate change with more volatile growing conditions. We evaluated a new approach to assess ProtUE and stability based on the V–GPC relationship instead of using only single traits. The study comprised 11,775 baking tests from 355 varieties grown 1988–2019 in 668 different environments in Germany. V was predicted by quadratic and linear regression functions for quality groups, indicating a reduction of ProtUE from 1988 to 2019. We introduced a dynamic and a static approach to assess ProtUE and stability as potential criteria in variety registration. We found a considerably lower heritability of the dynamic ProtUE (h2 = 43%) compared to the static ProtUE (h2 = 92%) and a lower dynamic stability (h2 = 32%) than for the static stability (h2 = 51%). None of these measures is in conflict with the selection for high V. In particular, V and static ProtUE are strongly genetically associated (r = 0.81), indicating an advantage of the static over the dynamic approach.

Recently, the introduction of GM maize in agricultural production in the EU and elsewhere has raised the issue of adventitious presence of GM seeds in conventional seed lots. Adventitious presence may occur in all arable farming, and at any step in the production of seeds or grain, or in processing of harvested product in the food/feed chain. As of today, there are no official thresholds governing the adventitious presence of GM seeds in conventional seed lots in Europe. However, it is assumed that GM admixture in seed lots could have a considerable influence on the level of adventitious presence in the non-GM harvested product. The experiments highlighted in this paper aim at the consequences of adventitious presence of GM maize seeds in conventional seed lots. It is shown for varieties belonging to the same maturity group that the final GM rate (% seeds) in the harvest product is nearly same as the initial seed admixture (% seeds). This corresponds to Hardy–Weinberg expectations. The variation depends mainly on the flowering coincidence, the site and climatic conditions. In cases where the admixed seeds are of different maturity group, the level of cross-pollination in the harvest product is reduced. Furthermore a comparison between the visual GM seed detection and real-time PCR detection was done. It is evident that the result of the real-time PCR detection method has a more variable uncertainty associated with its results than the visual seed testing method. The accuracy of prediction from % GM seed to % GM DNA depends on the reference material used for calibration curves.

Several biological containment methods have been developed to reduce pollen dispersal; many of them only have a proof of concept in a model plant species. This review focuses on biological containment measures which were tested for their long-term efficiency at the greenhouse or field scale level, i.e. plastid transformation, transgene excission, cleistogamy and cytoplasmic male sterility (CMS). Pollen-mediated gene transfer in transplastomic tobacco could occur at very low frequencies if the predominant mode of inheritance is maternal. Transgene excision from tobacco pollen can be made highly efficient by coexpression of two recombinases. For cleistogamous oilseed rape it was shown that some flowers were partially open depending on genotypes, environment and recording dates. Reports on the stability of CMS in maize and sunflower indicated that there is a high variability for different genotypes under different environmental conditions and over successive years. But for both crop types some stable lines could be selected. These data demonstrate that the biological containment methods discussed are very promising for reducing gene flow but that no single containment strategy provides 100% reduction. However, the necessary efficiency of biological containment methods depends on the level of containment required. The containment level may need to be higher for safety purposes (e.g. production of special plant-made pharmaceuticals), while much lower containment levels may already be sufficient to reach coexistence goals. It is concluded that where pollen-mediated gene flow must be prevented altogether, combinations of complementary containment systems will be required.