Abstract: An embryological investigation on the development of female gametophyte formation and embryogenesis in rice HDAR was made. The results revealed that the aposporous embryo sacs originated from certain somatic cells in the vicinity of megasporocyte. As aposporous initials developed simultaneously with megaspore mother cell and competed with each other,either multiple embryo sacs or sometimes only single embryo sac could be observed at later stage in one ovule. Their multiple embryo sacs differed extensively to each other in shape, structure, and polarity. Also, egg-cell in certain embryo sacs, which were difficult to determine their origins, possessed the capacity for parthenogenesis. The coexistence between apomictic ovary and sexual suggested that apospory in observed materials might be a typical facultative apomixis.

Key words: apomixis, apospory, parthenogenesis, embryology

摘要： 为进一步确定水稻HDAR的无融合生殖胚的倍性及发生类型，系统观察了胚囊的发生发育。结果表明水稻HDAR中具有一定频率的无孢子生殖胚囊和由卵细胞孤雌生殖而形成的无融合生殖胚。

关键词: 无融合生殖, 无孢子生殖, 孤雌生殖