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

摘要：

转基因植物在批准商业化之前通常要求在控制条件下开展实验。我国规定转基因油菜田间试验的隔离距离为1 000 m,该距离大于世界上绝大多数国家和地区的规定。转基因油菜基因流研究的数据显示,自然条件下甘蓝型油菜品种间的天然异交率一般不超过3%,多数在1%以下,隔离距离和保护行可以显著降低异交率,隔离距离400 m处异交率低于0.01%。白菜型油菜、自交不亲和系和雄性不育系的异交率则要高得多。建议对转基因油菜的安全监管采取分类管理和阈值管理的原则,在0.1%允许阈值下,普通甘蓝型油菜的隔离距离可设为400 m,而以异花授粉为主的其他油菜（包括白菜型油菜与其他类型油菜的自交不亲和系和雄性不育系）的隔离距离可设为1 000 m。

关键词: 油菜;基因流;异交率阈值;隔离距离