The rate and its determining factors of gene flow between two herbicide-tolerant GM rapeseed varieties and seven varieties from six Brassica species was studied under the paired growth and natural pollination conditions. This study will provide scientific evidence for the evaluation of the ecological safety of growing GM herbicide-tolerant rapeseed crop. At the year 2000/2001 season, the pollen donor glyphosate-tolerant GM rapeseed variety Q3 plants were grown in pairs with each of the seven pollen receptor...