含笑小孢子的发生、雄配子体的发育及其系统学意义

Microsporogenesis, development of male gametophyte in Michelia figo and their systematic significance

关键词:  含笑  小孢子发生  雄配子体  花药壁  系统学

Key words:  Michelia figo  microsporogenesis  male gametophyte  anther wall  systematics

摘要:

含笑的花药具4个小孢子囊,花药壁由表皮、药室内壁、3～6层中层和绒毡层组成。绒毡层细胞在发育后期由单核分裂为2核,原位解体,为腺质型; 小孢子母细胞在减数分裂过程中胞质分裂为同时型,小孢子四分体为四面体型,也有左右对称型的; 成熟花粉为3细胞型。在前人对含笑小孢子发生和雄配子体发育的观察描述基础上,丰富了含笑的胚胎学资料,并对其系统学意义进行了探讨。

Abstract:

For Michelia figo,there are four microsparangia in the anther whose wall is composed of epidermis,endothecium,3-6 middle layers and a tapetum. The antheral tapetum,consisting of monocyte-or binucleated cells,degenerated in situ,thus belonging to glandular type. The simultaneous cytokinesis in microspore mother cells leads to tetrahedral as well as isobilateral(bilaterally symmetrical)tetrads. The mature pollen grains are 3 celled. In the present study embryological features of M.figo were depicted further based on the former relative reports and their systematic significance was discussed.