assessment of the deliberate release of two model transgenic crop plants,
oilseed rape and sugar beet
and objectives (1)
Biotechnological techniques will broaden the range of germplasm available
to plant breeders by producing new gene combinations containing desirable
DNA sequences that are not available from other sources or by making them
accessible. The potential and limitations of the new techniques are not,
as yet, fully understood. This study aimed to assess the entire range
of safety issues associated with the deliberate release of genetically
modified plants (GMP) into the environment. We studied two model crop
species: oilseed rape (OSR) and sugar beet (Beta vulgaris).
project was a direct follow-on from EC projects:
and BAP-0371/0384/ 0408/0423
Approach and methodology
To assess the distribution of genes via pollen, field studies were carried
out in the UK, Belgium and France. Studies were designed to consist of
source area, containing the GMP and a catcher
area. The source and catcher areas were either located adjacent to each
other or were separated. The GMP carried an easily traceable marker such
as a colour gene marker.
We aimed to assess the potential and likelihood of gene transfer from
OSR to four of its most predominant wild Brassicaceae: B. campestris,
B. adpressa, Sinapis arvensis and Raphanus raphanistrum.
We studied the pollination ability, the production of F1 hybrids
under field and forced conditions and the reproductive potential of F1
We used endogenous markers and genes introduced by genetic modification
to produce interspecific hybrids with wild relatives of sugar beet: Beta
maritima, B. atriplicifolia and B. macrocarpa. We evaluated
the competitive ability of the hybrids in mixed populations in the greenhouse
and in the field.
Computer modelling was vital for predicting the importance of each biological
parameter and providing feedback on experimental design. Based on the
general model incorporating the experimental parameters, simulations can
be made on the impact of the particular traits.
Field of rape seed.
Main findings and outcome
Results of the pollen distribution experiments were consistent across
years and locations but were dependent on the experimental design. The
effective pollen dispersal is mainly limited to the immediate vicinity
(25 to 35 metres) of each plant. However, pollen could be detected at
low frequencies at 100 metres from the pollen source.
Outcrossing experiments confirmed the potential for gene transfer in B.
campestris. B. adpressa, S. arvensis and R. raphanistrum
could only transfer genes to OSR under specialised conditions.
Due to genetic barriers hybridisation of sugar beet with B. atriplicifolia
and B. macrocarpa was less frequent than with B. maritima.
The results of the fitness experiments confirmed that the traits investigated
did not convey any competitive advantage to the transgenic sugar beet.
Methods were developed for the design and monitoring of greenhouse and
field trials using GMP. We developed methods to quantify some aspects
of the performance of GMP.
The agronomic performance, in the field, of GMP did not differ significantly
from non-modified plants. For both modified and non-modified plants the
performance in the field was not completely predictable from the performance
in the greenhouse. However, greenhouse tests may be valuable in predicting
major changes in growth behaviour.
The fitness of GMP evaluated in this study was not significantly different
from the corresponding non-modified plants.
Pollen dispersal from plants allowed to flower openly in the field was
largely confined to the immediate vicinity of the test field. Effective
pollination at long distance was negligible.
The possibility for gene transfer to related species was dependent on
the crop species.
Dale P.J., "R&D regulation and field trialling of transgenic
Trends in Biotechnology, 13, 1995, pp. 398-403.
J.A., Parkinson R. & Dale P.J., "Evaluating the effectiveness
of isolation distances for field plots of oilseed rape (Brassica
napus) using a herbicide-resistance transgene as a selectable
Plant Breeding, 114, 1995, pp. 317-321.
P.J. & Irwin J.A., "The release of transgenic plants
from containment, and the move towards their widespread use in
Euphytica, 85, 1995, pp. 425-431.
E., Danielou V., Darmency H., Boucher F., Maillet J. & Renard
M., "Gene dispersal from transgenic crops. I. Growth of interspecific
hybrids between oilseed rape and the wild hoary mustard".
Journal of Applied Ecology, 32, 1995, pp. 803-808.
E., Fleury A. & Darmency H., "Gene dispersal from transgenic
crops; II. Hybridization between oilseed rape and the wild hoary
Sexual Plant Reproduction, 9, 1996, pp. 189-196.
H., Lefol E. & Fleury A., "Spontaneous hybridisations
between oilseed rape and wild radish".
Molecular Ecology, 7, 1998, pp. 1467-1473.
October 1991 September 1993
Aventis Crop Science N.V.
Le Rheu (FR)
Centre for Plant Breeding Research
John Innes Centre of Plant Science Research
Maribo Seed Danisco A/S
Monsanto Europe S.A.
Université de Paris Sud (FR)
The Royal Veterinary and Agricultural University
The National Forest and Nature Agency