高浓度激素喷穗对多胚水稻胚胎发育的影响

Effect of High Concentration of Hormone on Embryo Development in Polyembryonic Rice

用无融合生殖“固定”水稻杂种优势是水稻遗传和育种中一个十分活跃的研究领域。近年来,我国一些研究,不仅已证实了水稻具有无融合生殖特性,而且获得一批低频率发生的水稻无融合生殖材料(即水稻多胚苗和单性生殖材料等)。但是,已发现的水稻无融合生殖材料最为突出的问题是可用于“固定”杂种优势的无融合生殖方式(即不定胚)的频率太低,通常只有百分之零点儿,难以直接应用。所以,如何提高不定胚的频率成为关键所在。鉴于水稻多胚苗中的不定胚发育与合子胚发育存在竞争关系。

The effects of high concentration of hormones, 2500 mg/kg 2, 4-D and 2500 mg/kg GA_3, 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.