The segregation on F2 in plant height of the cross from IR31851/ZR6 showed normal distribution indicating that ZR6 has sdt semidwarfing genes. And the suitable seeding time of the cross,IR31851/ZR6 is about June 10.

• IR_(31851)/ZR_6组合的F_2代株高分离呈正态分布,表明 ZR_6带有与籼稻等位的 sd_1半矮生基因,该组合的适宜播种期为6月10日左右。