The fertility investigation under different sowing-stage was conducted for 7 rice dual-purpose genic male sterile lines in 3 ecological regions of Guizhou.

• 在省内3个不同生态地区，对7个两用核不育系的分期播种的育性观察试验表明，核不育系不育期的长短变化规律是随海拔增高由长变短；