摘要
莲(Nelumbo nucifera Gaertn)的子叶从子叶原基发生至成熟休眠,整个生长期约30天,伹受品种、花期、气温和日照的影响,有3—5天的差异。光学和电子显微镜的观察表明,叶内细胞的形态结构在发育过程中变化巨大,子叶发育格局类似双子叶植物。整个发育过程份四个发育阶段:Ⅰ.细胞增殖,形态发生;Ⅱ.细胞液泡化,体积扩大;Ⅲ.细胞处于功能期,大量合成和积累贮藏物质;Ⅳ.脱水收缩,成熟休眠。位于子叶不同部位的叶肉细胞的发育不同步,通过前三个发育阶段所需时间也各不相同。细胞液泡化和进入功能期的位置顺序是从基部到顶部,先外层后内层。受精后25—26天,几乎全部细胞依次进入成熟休眠。
The whole growing period (from the formation of cotyledon primordia till ripe) of co tyledons of Nelumbo nucifera takes about 30 days,but can be varied in 3—5 days according to the varieties,temperature,light duration and its intensity during the blooming season.The observations by light and electron microscopy show that the feature and structure of mesophyl- lous cell are changed greatly during its development.The developing pattern of the cotyle- dons is similar to that of dicotyledonous plants.For comparitive analysis the authors divide the whole developing process into four developing phases:Ⅰ,the phase of cell division and organ formation;Ⅱ,the phase of cell vacuolation,elongation and swelling;Ⅲ,the phase of main physiological function in which the materials are largely synthesized and accumulated and Ⅳ,the phase of dehydration,contraction,maturation and dormancy.The development of mesophyllous cells in different part of cotyledons is not simultaneous and the duration of each phase is also different.In general,the developing order is from the base to the top and first the outlayer then the centre.On the 25—26th days after fertilization almost all mesophyl- lous cells are developing into maturation and dormancy by order.This is the first report about the developing pattern of cotyledons and the ultrastructural changes in mesophyllous cells of Nelumbo nucifera.
基金
国家自然科学基金
关键词
莲
子叶发育
超微结构
Cotyledons developing pattern
Fine structure
Nelumbo nucifera
