应用RAPD标记检测了 1 6个四川省及其它地区的杂交水稻骨干保持系之间的遗传差异。 1 0个随机引物共扩增出 84条带 ,品种间的多态性频率为 72 6 2 %。保持系间的遗传距离小 ,在 0 0 5 2 6～ 0 2 1 5 2之间。 1 6个保持系按UPGMA聚类法可聚为三类。大多数保持系聚为一类 ,表明其遗传差异小。增大保持系的遗传多样性是四川省杂交水稻育种的重要任务之一。 RAPD markers were used to detect the genetic differences among 16 maintainer lines of hybrid rice in Sichuan Province and other regions. A total of 84 bands were amplified with 10 random primers. The frequency of polymorphism was 72 6 2%. Keeping the genetic distance between lines is small, between 0 0 52 6 ~ 0 2 1 5 2. Sixteen maintainers can be clustered into three categories by UPGMA clustering. Most remain clustered into one category, indicating a small genetic difference. Increasing the genetic diversity of maintainer lines is one of the important tasks of hybrid rice breeding in Sichuan Province.