Abstract: By using pollen staining technology, this paper studied the drift frequency and distance of transgenic phyA maize pollen. The risk probability of the pollen drift differed in different directions, and decreased with the increasing distance from the central planting area of transgenic phyA maize. The pollen drift risk probability was the maximum (65.6%-82.5%) at the place of 1 m distance from the central planting area of transgenic phyA maize, which was significantly greater than that (21.8%) at the place of 3 m distance from the central planting area. At the places of above 5 m distance from the central planting area, the pollen drift risk probability was less than 8.7%. Due to the different weather conditions of sampling dates, the pollen drift distance was somewhat different, and the maximum distance of pollen drift could be 35 m from the central planting area of transgenic phyA maize.

Key words: food web structure., trophic relationship, wetland ecosystem, food source, stable isotope