摘要
用光镜和透射电镜的系统观察表明,小孢子母细胞间胞质通道的发育是棉花小孢子发生过程中最显著的特点之一。胞质通道的形成始于减数分裂的前夕,在减数分裂Ⅰ期间充分拓宽,在减数分裂Ⅱ期间逐渐消失。胞质通道的存在仅限于相邻小孢子母细胞的壁之中.胞质通道的孔径分布为150~3300 nm,大部分细胞器均能通过充分拓宽的胞质通道进行胞质间运动。胞质通道的形成可能与小孢子母细胞减数分裂的同步性有关。偶尔也能观察到核物质的胞间穿运,但这种核物质表现出降解的状态,推测这是非正常发育小孢子母细胞间降解原生质胞间转移的现象。
Light and electron microscopy studies revealed that the cytoplasmic channel in the wall of adjacent meiocytes was an obvious feature during microsporogenesis in Gossypium hirsutum.The channels were initiated in the premeiotic period and persisted throughout meiosis Ⅰ.They disappeared during meio- sis Ⅱ.The cytoplasmic channels were restricted to the sides where the interfaces of neighbouring meio- cytea were in contact.The diameters of the channels range from 1500 nm to 3300 nm,which are large enough for the passage of any cytoplasmic components between meiocytes.The presence of the channels may account for the synchroneity of meiocytes in meiosis.Cytomixis is seldom observed,thus it seems to be an abnormal phenomenon and would not he expected appearing in normally developing meiocytes.
关键词
棉花
小孢子母细胞
减数分裂
Gossypuim hirsutum
microsporocyte
meiosis
cytoplasmic channel