黄花蒿大孢子的发生和雄配子体的形成

黄花蒿大孢子的发生和雄配子体的形成(7800字)
摘  要：应用石蜡切片技术，对黄花蒿大孢子发生与雌配子体发育进行了观察．结果表明：（1）黄花蒿子房下位，一室一胚珠，倒生胚珠。胚珠具有两层珠被，内珠被的发育较外珠被早，两层珠被形成珠孔，薄珠心。（2）珠心表皮下一个孢原细胞发育成造孢细胞，造孢细胞进一步发育成大孢子母细胞，大孢子母细胞减数分裂形成线状的四分体，合点端的大孢子为功能大孢子。（3）胚囊发育为蓼型，胚囊成熟后为七细胞八核胚囊，两极核受精前融合成次生核，反足细胞退化较晚。

关键词：黄花蒿；石蜡切片；雌配子；大孢子；发育

The Artemisia annua megaspore and the Formation of Female Gametophytes in Artemisia annua
Abstract: The Artemisia annua megaspore and the Formation of Female Gametophytes in Artemisia annua were observed by using method of traditional paraffin sections. Results were list as follows: (1) Artemisia annua ovary is under Corolla, an ovary with one ovule, ovule is anatropous ovule. Ovule with two layers of integument, inner integument development earlier than the outer integument, the double integument built the micropyle, it has a thin bead wall. (2) The nucellar epidermis of a spore of the original cell periclinal divisions produce peripheral cells and sporogenous cells, the sporogenous cell grow into spore mother cell, megaspore mother cell meiosis to tetrad formation of linear, chalazal megaspore as the functional megaspore. (3) The Polygonum type embryo sac, embryo sac mature eight-nucleate embryo sac of seven cells, two polar nuclei fuse before fertilization into the secondary nucleus, antipodal cells degenerate later.
Key words: Artemisia annua; Paraffin sections; Female gametes; Megaspore; Development