摘要
用一种改进的ＦＩＴＣ微管蛋白免疫荧光和ＤＡＰＩ双定位的技术，在紫外光激发下能同时显示花粉管中的生殖细胞（ＧＣ）和营养核（ＶＮ）。在朱顶红（Ａｍ ａｒｙｌｌｉｓ ｖｉｔｔａｔａ Ａｉｔ．）花粉萌发的最初１—２ 小时内，ＧＣ和ＶＮ 都有可能从花粉粒先进入花粉管。然而，在ＧＣ分裂前ＶＮ 总是变为在ＧＣ之前和接近花粉管顶端的位置。因此，在生殖细胞先进入花粉管的情况下，ＶＮ必然越过ＧＣ而使位置发生变换。根据观察的图象可以总结出三种基本的过程。１． 在萌发后约２小时，营养核位于ＧＣ后端延伸的细胞质附近，形成暂时的物理联结。２．ＶＮ 进一步向前更快地移动，以致整个ＶＮ 与ＧＣ并列和紧靠，它们常相互扭结在一起。３．ＶＮ 越过ＧＣ，并变为高度延长，它的后端常部分地插入生殖细胞的细胞质中。观察结果表明：ＶＮ和ＧＣ通过花粉管时移动的速度是明显不同的。这种速度的差别可以认为存在各自独立运动的机制，以及ＶＮ 和ＧＣ本身结构的差别。
A modified technique, FITC tubulin immunofluorescence and DAPI localization to demonstrate simultaneously both the generative cell (GC) and the vegetative nucleus (VN) in the pollen tube under ultra violet excitation, was developed sucessfully. During the germination of the pollen tube of Amaryllis vittata Ait.the GC and the VN, either being the first one, entered the tube within the first 1—2 h from the pollen grain. However, before the time of GC division, the VN was always positioned distally near the tip of the tube. In case when the GC entered the tube first, then the VN must have a positional shift in order to pass over the GC.The detail processes of positional shift between the GC and the VN were observed. Three basic processes were demonstrated: 1. The anterior end of the VN first reached the vicinity of the posterior attenuated extension of the GC about 2 h following germination forming a temporal physical association. Sometimes their both ends could be inserted into one another for certain extent. 2. The whole VN moved forward and contacted in parallel with the GC until they became twisted together and 3. The VN passed over the GC and greatly elongted lengthwise. Its posterior part became inserted into the anterior end of the GC. The behavior of positional shift between the VN and the GC in the pollen tube seems to be an adjustment of their diameters to fit the narrow tube. A conclusion may be drawn that the rate of movement between the VN and the GC was apparently different during the passage through the tube. Such difference may presumably be accompanied by the independent motive mechanism and structural difference between the VN and GC themselves, which provide their motive force for movement in the tube.
基金
国家自然科学基金
高等学校博士学科点专项科研基金
关键词
朱顶红
花粉管
营养核
生殖细胞
Amaryllis vittata
Pollen tube
Generative cell
Vegetative cell
Positional shift
