Danish research projects in relation to co-existence

Co-existence in white clover

One of the subprojects in the DARCOF⁷ III project SEED, which began in spring 2006, studies gene dispersal in white clover, including the extent of self-incompatibility and behaviour of pollinating insects. The project aims to contribute results for establishing cropping methods for

7 Danish Research Centre for Organic Food and Farming

reduction of gene dispersal in the production of white clover seeds. The participators are Risø and DJF, which is in charge of the project (DARCOF, 2007).

Consequences of co-existence between GM oilseed rape and organic growing of oilseed rape In a PhD project under the Research School for Organic Agriculture and Food Systems (SOAR) at Risø National Laboratory at the Technical University of Denmark and the Faculty of Life Sciences at the University of Copenhagen, population dynamics, the frequency and distribution of volunteer oilseed rape in organic fields with different tillage practices (row cropping versus broadcast sowing) and the frequency of hybrids between wild turnip and winter oilseed rape are studied in organic fields. Furthermore, the purity of winter oilseed rape is studied through molecular markers and the results are compared with the varietal purity calculated from morphological markers which is the present practice for testing varieties and approval of seed lots (Andersen, 2005).

Cross-pollination from GM to non-GM oilseed rape fields

A model for pollen dispersal of genetically modified oilseed rape to non-GM oilseed rape fields has now been developed and can be used for practical advice (Damgaard & Kjellsson, 2005). The expected cross-pollination frequencies in relation to the distance from the field and the width of a buffer zone can be forecast from the model predictions. The probability of GM dispersal and subsequent adventitious presence is less for large organic fields than for small. The GM dispersal for large fields is expected to be very small (approx. 0.1%) at isolation distances of more than 100 m. The use of a buffer zone (5 m) around a non-GM field will reduce the GM dispersal to the field by approx. a third. The preliminary results were already used in the 2003 Report.

Genetic difference between certified seed and field crop

Under the DARCOF II project TOPRO (DARCOF, 2005) a genetic analysis method (ISSR) was developed for testing for adventitious GM presence in oilseed rape lots via pollen and seeds (Simonsen et al., 2004). In a trial field with the oilseed rape variety Canberra the genetic profile of some plants was genetically different from the seeds and also different from the certified seed. A close analysis indicated that the main cause was germination of oilseed rape plants from volunteers from previous growing of oilseed rape and that pollen dispersal from the neighbouring field was of minor importance. The conclusions of the study are that harvesting methods, seed shedding and seed survival in the soil should be included more in the problems relating to adventitious dispersal of GM material to organic or conventional varieties.

Forecasting wind dispersal of GM pollen from oilseed rape and rye

A computer model has been developed that can forecast levels of wind dispersal of GM oilseed rape and rye pollen to other fields in the landscape (Geels et al., 2004). Apart from the meteorological data, the dispersal model involves the flowering season of the crop and physical parameters for the pollen for calculating the dispersal. The modelling of the spatial distribution of oilseed rape pollen for three sites and for five pollen seasons indicate that pollen dispersal by wind varies a lot from season to season and from locality to locality. The modelling supports the principle that distance between the fields is an effective measure for reducing the relative share of GM pollen over a non-GM field. However, the distribution of the fields in the landscape and the predominant wind direction in the area in question are also extremely important parameters for the total transport of pollen.

Methods for ensuring GM free organic seed from vegetable seeds and forage crops

Under the DARCOF II project VEFOS (DARCOF, 2005) work has been carried out on methods to ensure the availability of organic vegetable and herbage seed. In this cooperative project, of which DJF was in charge, the focus has been especially on developing techniques for producing seed for crops requiring a particularly high degree of genetic purity (vegetables) and for which relatively limited amounts of seed are used (oilseed rape). Publications from the project can be found on http://www.orgprints.org/view/projects/da2f5.html.

Statistical methods for assessing the total adventitious presence of GM material

In the final assessment of adventitious presence of GM content in a seed lot, all sources of dispersal must be considered. Damgaard et al. (2007a, in press) described a method for calculating a

combined estimate of the probability of selecting a GM seed from a seed sample at the point of distribution as a consequence of adventitious presence. As an example calculation of the production of oilseed rape in Denmark was used. This method is based on an assessment of the probability in the various subprocesses, such as seed propagation, soil tillage, seed bank, cross-pollination, harvesting, transportation, storage and sale. By using this theoretical probability method, the total expected adventitious presence of GM material was less than by using simple addition of frequencies, which is most often used in connection with assessments of adventitious presence.