Abstract: In crossing of the 8 autotetraploidy rices (Oryza sativa, 2n=4x=48), APIV (4) , IR36 (4) , Zixuedao (4) , Ce 64 (4) , Minghui 63 (4) , IR28 (4) , Ce 90 (4) and Gui 99 (4) used as the females, with Pennisetum alopecuroides (2n=2x=18) used as the males, the seeds were obtained, but no seed was got in the crosses of the 3 diploidy rices (Oryza sativa, 2n=2x=24), APIV (2) , Ce 90 (2) and Zixuedao (2) used as the females, with Pennisetum alopecuroides (the males). The pollen grains of the male induced some of the ovaries in the caryopses of the females to inflate obviously after the pollination. The inflating effect in the autotetraploidy rices was more obvious than in the diploidy rices. In the crosses of the autotetraploidy rices used as the females, some seeds could be got, but more seeds were obtained in these crosses by the special treatment that the DH solution was put into the caryopses before the pollination. It is suggested that autotetraploidy rices are better females in the distant hybridization due to the fact that they are weaker in sexually reproductive ability.

Key words: Oryza sativa, Pennisetum alopecuroides, distant hybridization, seed, polyploid

摘要： 利用A P IV (4)、IR36(4)、紫血稻(4)、测64(4)、明恢63(4)、IR28(4)、测90(4) 和桂99(4) 等8 个同源四倍体水稻(Oryza sativa, 2n= 4x= 48) 为杂交母本, 以狼尾草(P ennisetum alopecuroides, 2n= 2x= 18) 为杂交父本进行杂交, 获得了实粒种子。但是, 在以A P IV (2)、测90(2) 和紫血稻(2) 这3 个二倍体水稻(Oryza sativa, 2n= 2x= 24) 为杂交母本, 以狼尾草为杂交父本的杂交组合中却没有获得实粒种子。在授粉后狼尾草的花粉粒能诱导杂交母本的子房发生明显膨大。在同源四倍体水稻中的子房膨大效应比二倍体水稻中的子房膨大效应更加明显。在以同源四倍体水稻为杂交母本的杂交组合中, 可以获得一些实粒种子, 但是, 如果在授粉前利用DH 溶液对同源四倍体水稻的去雄颖花进行处理后再授狼尾草的花粉粒则能获得更多的实粒种子。结果暗示由于同源四倍体水稻具有比较弱的有性生殖能力, 在远缘杂交中它们是比较好的杂交母本。

关键词: 水稻, 狼尾草, 远缘杂交, 种子, 多倍体