摘要
运用光学和电子显微镜对银杏雄配子体发育进行了研究。结果显示,花粉粒进入贮粉室后,通过侧向萌发产生吸器状花粉管。精原细胞在发育过程中依次产生生毛体、液泡状结构和纤维颗粒体。生毛体由一个电子致密的核心和由此向周围发散出的辐射状中心粒组成;液泡状结构为染色较深、质地均匀,看不到膜结构包被的圆球形,其周围细胞器丰富,DAP染色证实液泡状结构中含有遗传物质。纤维颗粒体染色很深,外形不规则。临近受精前,精原细胞纵向分裂形成2个半球形的精细胞,成熟精核直径约40μm,而受精时与卵核融合的精核直径约20μm,说明精核在受精前体积浓缩。精核以变形虫式运动穿过较小的颈卵器口,进入卵细胞与卵核融合。在受精前的一些精细胞中可观察到其核内出现一个直径约20～30μm染色较深的球形区域,推测精核浓缩前遗传物质先浓缩到一个区域,然后精核浓缩。
Light and electron microscopes were used to probe the development of male gametophytes of Ginkgo biloba in the study.After the pollen entered the pollinic chamber,it laterally germinated to form a haustorial pollen tube.The spermatogonia successively formed blepharoplasts,vacuole-like structures and filamentous bodies in their development a blepharoplasts consisted of one electron-dense core and spokewise centrioles radiating away from the core;a vacuole-like structure,surrounded by abundant organelles,showed dark staining color and homogenous texture which prevented the spheroidals wrapped by the vacuole-like structure membrane structure from being seen, and the staining by the DAPI proved that it contained genetic substances.The filamentous bodies had dark staining color and anomalous shape.Before approaching its fertilization,a spermatogonium longitudinally divided into two semi-sphere sperm cells;the mature spermo-nucleuses of the cells had a diameter of 40 μm but they had a diameter of 20 μm once they united the egg nucleus.This indicated that the spermo-nucleuses shrinked in size before their fertilization.The spermo-nucleuses moved into the egg cells through the archegonium meatus in an amoeboid movement,and then united with the egg nucleuses.Some sperm cells were observed to have a spherical region of dark color with its diameter ranging between 20 μm and 30 μm before fertilization,and thus the spermo-nucleuses was presumed to first concentrate their genetic substances in a certain area and then shrunk themselves.
出处
《西北植物学报》
CAS
CSCD
北大核心
2005年第7期1350-1356,共7页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金项资助目(39570048)
关键词
银杏
精原细胞
精细胞
生毛体
液泡状结中勾
纤维性颗粒体
Ginkgo biloba
spermatogonium
sperm cell
blepharoplasts
vacuole-like structure
filamentous body
