Abstract: The effects of high concentration of hormones, 2500 mg/kg 2,4-D and 2500 mg/kg GA₃, on the embryo development of five polyembryonic rice by spike-spraying were studied. It showed that both the hormones had significant effect on killing zygotic proembryo, and the rate of killed embryos ranged from 15. 6% to 56. 2%. The frequencies of adventitious proembryo obviously increased in hormone treatment and the highest frequency was 4. 8%, which was nearly 4 times as high as that in CK. But the effect of hormone on sex-polyembryo frequency varied with different materials. It seemed that both hormones slightly decrease the polyembryo frequency of polyembryonic materials except that the frequency of PM3 rose sharply. Moreover, some kinds of abnormal embryos, such as "dwarf embryo", " giant embryo" etc., were observed.

Key words: Apomixis, Embryology, Hormone, Polyembryony

关键词: 水稻, 胚胎学, 激素, 无融合生殖