THE RELEASE OF GENETICALLY-MODIFIED GRASSES .1. POLLEN DISPERSAL TO TRAPS IN LOLIUM-PERENNE

As part of a series of experiments on determining the risk of introduc ing genetically modified wind-pollinated forage grasses an experiment on pollen dispersal was conducted and-the use of theoretical descripti ons to predict dispersal in model systems investigated. Pollen traps w ere placed around a central source of Lolium perenne. Traps were expos ed with their sticky surfaces towards and away from the pollen source and also facing skywards during four stages of anthesis (early, mid 1, mid 2 and late). There was a great deal of variation in dispersal ove r time and to traps of different orientations. Twelve datasets were co llected and used to comprehensively test Bateman's equations for the w ind dispersal of pollen. The equations were not particularly useful fo r describing dispersal over distance and clearly need to be modified t o take factors such as wind direction into account.