| Abstract: | Gastrodia elata B1. is a species of parasitic orchid, its organized structure is much reduced. Although its embryo sac is rather simple (4-celled), the double fertilization proceeds normally. The fusion of sexual nuclei is referred to the premitotic type. The primary endosperm nucleus may divide once or not, and degenerate on the 6th or 7th day after fertilization. The nucleoli of generative and vegetative nuclei in the pollen tube are conspicuous. Generally the sperms form after the contact between the generative cell and vegetative nucleus. The nucleoli of sperms are also clearly distinguished. Daring the fusion of male and female nuclei in fertilization two male nuclei always show the distinct nucleoli. |
