东京野茉莉雌雄蕊的形态及显微结构

【目的】了解东京野茉莉(Styrax tonkinensis)花部及雌雄蕊的形态及内部显微结构,探寻其花粉败育原因。【方法】运用光镜和电镜技术,对其雌雄蕊内外部形态特征、显微结构和超显微结构进行观察研究。【结果】(1)每朵两性花中有雄蕊10枚,由花丝和花药组成。花丝宽(0.38±0.12)mm,长(8.24±0.72)mm,成熟花药由2个狭长圆形的药室组成。成熟花粉在扫描电镜下可见3或4个萌发沟,外壁有细网状纹饰,还发现有形态皱缩发育不良的花粉。透射电镜显示发育良好的花粉壁有2层,细胞内质浓厚,含有高尔基体、较多的线粒体、高电子致密物质和淀粉粒等结构。(2)雌蕊1枚,由柱头、花柱和子房组成。柱头上有"Y"形裂沟和椭球状乳突,传粉后,柱头上有分泌物。花柱中空。子房3室,多枚倒生胚珠;发育后期,只有1~2个发育为种子,其余退化。【结论】东京野茉莉花部特征符合安息香科特征,花粉粒3种形态;柱头湿型,胚珠倒生;可育花粉粒和珠被细胞内细胞质浓,细胞器较多。

Microstructure of pistils and stamens in Styrax tonkinensis

Objective] Learn the morphology and microstructure of flowers, pistils and stamens in Styrax tonkinensis, and probe into the reasons of pollen abortion.Method]The macrostructure, microstructure and ultrastructure of the pistils and stamens were studied by light and electron microscopy. Result]① There were 10 stamens composed of fila?ments and anthers in each bisexual flower. The width and length of a filament was approximately (0.38±0. 12) mm and (8.24±0.72) mm, respectively. The mature anthers were composed of two narrow circular chambers. Three or four ger?minal furrows in the exine of mature pollen with finely reticulate ornamentation were observed by scanning electron mi?croscopy( SEM) . Furthermore, we observed a form of shrunken, poorly developed pollen. Using transmission electron microscopy, we observed that in well-developed pollen cells, there were two layers in the pollen wall, a dense cyto?plasm, some Golgi apparatus, a large number of mitochondria, and a high proportion of electron dense materials and starch grains. ②There was one pistil per flower composed of a stigma, style and ovary. There were"Y"?type furrow and ellipsoidal mastoids on the stigma, and secretions after pollination. The style was hollow, and there were many anatro?pous ovules attached to the placenta on the inner wall of its three?chambered ovary. In the late period of development, only one or two of these ovules developed into seeds, whereas the others became degraded.Conclusion]The characteris?tics of S. tonkinensis flower were accordance with Styracaceae. The pollen had 3 forms. The stigma was wet type. The o?vule was anatropous. There were rich cytoplasm and more organelles in the cells of the pollen and the integument.