Workpackage 1: Biological Approaches For Gene Flow Mitigation

Workpackage leader

Joachim Schiemann Federal Biological Research Centre for Agriculture and Forestry Institute for Plant Virology, Microbiology and Biosafety Braunschweig, Germany

The development and application of plant biotechnology is being delayed by both real and perceived threats to human and animal health, and to the environment. Development of techniques for significantly restricting or preventing gene flow between plants would significantly improve the food and environmental safety of GM plants and their products, and remove many of the human health and environmental concerns. In addition, European society is concerned that the introduction of GM foods and products will remove their ability to make informed choices about the food that they purchase and eat. Development of techniques for restricting or inhibiting gene flow between plants would go a long way towards removing societal concerns and allow choices to be made. In addition, the co-existence of different forms of agriculture in the EU should be developed. Development and application of gene flow restriction and crop containment measures will be of vital importance to facilitate co-existence of farming systems.
At the field level, adventitious presence of GM material in non-GM production could have several causes. The most important biological parameters are flowering biology (mainly the ability of pollen to move from one type of crop to another), the ability of the crop to make fertile crosses with related wild relatives that may grow in or around the production field, and the survival ability of its seed and other storage structures if they are left in the field.
WP1 is aimed at assessing and developing whenever necessary biological tools and methods to allow producers to grow kind of crops they choose with minimised risks of admixture between GM, conventional and organic products. Therefore, the general objective of this WP is to analyse, further develop and validate methods for restricting gene flow during cultivation by removing or reducing the fertility of pollen or seeds as well as to identify the major drivers of pollen flow over fragmented landscapes. It will focus at first on crops for which GM varieties are already approved or close to authorisation (maize and rapeseed), at second on crops whose authorisation is expected during the next 5 years.

The studies will focus on :

• landscape scale (esp. over fragmented landscapes) and long distance (several hundreds meters) gene flow experiments including multiple pollen sources in order to provide data for developing models and verification of predictions from these models, with special emphasis on buffer zones with different intervening crops,
• analysis, development (if necessary) and validation of biological mitigation techniques like hybrid systems on the basis of male-sterile GM plants, and
• analysis whether mitigation techniques work reliable in different crops and in special situations.

Large scale studies will be performed with maize and rapeseed, small scale studies (including green house) with sunflower, tomato, and tobacco (as model plant). Based on the results of data mining (in the frame of the EU-funded SIGMEA project) and micrometeorological knowledge, pollen-mediated gene flow will be modelled (models developed in SIGMEA). The typical surroundings of maize fields in various representative landscapes of Germany, France, UK, and Bulgaria will be surveyed, including the size and shape of the fields, the distances between neighbouring maize fields, and the crops surrounding GM and non-GM maize fields. The surveyed data will be implemented in the existing models and gene flow experiments will be based on assumptions derived from the improved models. Thus the experiments will be planned in the first year, performed in the second and third years, and the results will be disseminated in the fourth year. If after mitigation analysis cleistogamy in rapeseed will be identified as useful, the material will be shared by most of the WP1 partners for field studies.

The main innovations of WP1 will include:

• assessments in real conditions and at large scale of bio-containment tools like cytoplasmic male sterility and cleistogamy,
• application of mathematical models for prediction of pollen distribution and impact over large distances and fragmented landscapes, and
• development of best practices for bio-confinement.

The main results of WP1 will include:

• experimental data on the reliability of bio-confinement methods obtained from real conditions and large scale benchmarking,
• monographs on biological containment techniques, and
• mathematical models for pollen emission and its impact on large distance dissemination.

In the frame of Co-Extra, WP1 will thus collect and synthesize the existing and developing biological approaches to mitigate cross-admixture within domestic and non-domestic crops. The resulting monographs, taking into consideration technical but also practical and economic aspects, should be incorporated into the (future) development of decision support tools to be available to the stakeholders. The project results will be analysed to develop strategies to come to decision support systems. Multi-sites experimental case studies will furthermore be launched on a few models of food and feed crops such as cytoplasmic male sterility of corn or cleistogamy for rapeseed.