Simulation and Assessment of Possible Environmental Risks Associated with Release of Genetically Modified Peas (Pisum sativum L.) into Environment in Central Europe

Environmental risks connected with the release of genetically modified peas into the environment were studied in simulated field experiments. They included (1) an assessment of pollen transfer and the rate of natural outcrossing between commercial peas (Pisum sativum), (2) the incidence and behaviour of insects visiting pea flowers and their role as potential pollinators, and (3) the inventory of other insect taxa in pea crop (not related directly to pea reproduction organs). Field trials were established (2001-2003) with two non-GM pea cultivars differing in flower colour, seed coat colour and whole plant habit that were grown in close proximity. Cv. Zekon with recessive traits served as a trap variety, cv. Arvika with dominant traits as a pollen donor. The seeds of the trap variety were completely harvested and sown each successive year (2002, 2003) to monitor the incidence of dominant traits in F1 generation. In the case of outcrossing, dominant traits would occur already in F1 generation. However, the occurrence of plants with dominant traits in the progeny of the trap variety was not recorded in any case during the whole experimentation period (ca 40 thousand F1 plants screened each year). Based on the obtained data we assume that the probability of outcrossing in recent commercial peas is extremely low (zero in our experiments). Among the species visiting regularly pea flower buds/flowers (pests, pollinators) the most frequent were pea weevil (Bruchus pisorum), pea aphid (Acyrthosiphon pisum), pea thrips (Kakothrips robustus), honey-bee (Apis mellifera), bumble-bees (Bombus sp.). Bruchus pisorum is a possible candidate for pollen transfer in unopened pea flowers. A list of insect taxa occurring in pea fields was created on the basis of the four-year monitoring (2001-2004).