黄花蒿小孢子的发生和雄配子体的形成

Microsporogenesis and Male Gametophyte Development of Artemisia annua L.

黄花蒿是当今优良抗疟药青蒿素的药源植物。采用石蜡切片法观察了黄花蒿小孢子发生及雄配子体发育的细胞学过程。黄花蒿花药为4室结构；横切面呈蝴蝶状排列；花药壁发育为典型单子叶型；花药壁中层在花药发育的较早期解体，其绒毡层由腺质型绒毡细胞组成，在花粉成熟前绒毡层细胞原位解体；花粉母细胞在减数分裂过程中，细胞分裂同步相差1～2个细胞周期，其细胞质分裂则为同时型；经2次分裂后形成的四分体为正四面体型；花药开裂前的成熟花粉粒为2细胞型，含1个营养细胞和1个具2个细胞核的生殖细胞。

Artemisia annua L. is only medicine source plant of artemisinin,a very effective antimalarial medicine. In this paper the conventional paraffin section was adopted to observation of the microsporogensis and the male gametophyte devel-opment of A. annua.The results are as follow：The anther has 4 chambers and organizes in a butterfly shape in its transec-tion. The development of anther wall belongs to the monocotyledonous type. The two middle layers of anther wall change from thickness into thinness in the earlier stage of the anther development and disintegrate in the dyads stage of the pollen mother cell （PMC）. The tapetum,of which each cell always disintegrates in the original position,is the secretory type.The cytokinesis after meiotic division of PMC is simultaneous type,and the microspore arrangement in the tetrad is tetrahe-dra1.The mature pollen grains,which contain 1 vegetative cell and 1 reproductive cell,belong to a 2-cell type.