观光木的小孢子发生及雄配子体发育的研究

Studies on Microsporogenesis and Development of Male Gametophyte in Tsoongiodendron odorum Chun

摘要:

采用石蜡切片法对观光木(Tsoongiodendron odorum Chun)的小孢子发生和雄配子体发育进行了解剖学研究。观光木的花药由花药原基发育而来，具4个小孢子囊，花药壁由表皮、药室内壁、2~3层中层和1~2层绒毡层组成。中层在小孢子四分体时期开始解体，最终消失；绒毡层为腺质绒毡层，细胞具1~2核，在花药发育过程中不断分泌各种物质，提供小孢子发育，直到花粉成熟绒毡层才自溶消失。初生造孢细胞分裂形成次生造孢细胞，次生造孢细胞再转化为小孢子母细胞，小孢子母细胞减数分裂的胞质分裂为修饰性同时型，四分体排列方式为交叉型、对称型或“T”型(极少)，成熟花粉粒二细胞型，开花时散出。观光木的成熟花粉粒存在严重的败育现象。

Abstract:

The microsporogenesis and development of male gametophyte in Tsoongiodendron odorum Chun were observed by using the paraffin section method. The anther was tetrasporangiate, originated from the stamen primordium. The anther wall was composed of epidermis, fibrous endothelium, middle layer (2~3 layers) and tapetum (1~2 layers). The middle layers became smaller at the tetrad stage, and disappeared at last. The tapetum was of glandular type, which degenerated to supply the nutrient to the pollens and finally disappeared when the pollens were mature. The primary sporogenous cells divided into the second sporogenous cells which would turn into microspore mother cells in a microsporangium. The cytokinesis in meiosis of the microspore mother cells was of modified simultaneous type, forming the decussate, isobilateral or T-shaped (rarely) tetrads. Mature pollen grains, which were dispersed at anthesis, were 2-celled type and degenerated seriously.