关键词: 油菜;基因流;异交率阈值;隔离距离

Abstract:

Prior to approval of commercialization, transgenic plants are required to be confined in order to prevent foreign gene dispersal. According to the current Chinese regulation of GMP biosafety assessment, the isolation distance for field experiment of GM rapeseed is 1 000 m, which is larger than required distance set by almost all countries and regions. According to the review of studies on rapeseed gene flow, the outcrossing rate of rapeseed (Brassica napus) is below 3%, and below 1% is the most cases. Isolation distance and buffer zone are effective ways to reduce outcrossing rate. Beyond 400 m the outcrossing rate becomes significantly lower than 0.01%, though it is much higher for the B. rapa, sterile lines and self-incompatible lines. It is suggested that biosafety management be based on the classification and threshold principles and that the isolation distance be adjusted to 400 m for common rapeseed varieties of B. napus while kept 1 000 m for the self-incompatible lines and sterile lines in the confined field experiment.

Key words: rapeseed, gene flow, outcrossing rate threshold, isolation distance