水生植物冷冻扫描电镜和常规扫描电镜成像效果比较

摘要

比较了三种水生植物(单星藻、芜萍和水蓑衣)的冷冻扫描电镜和常规扫描电镜成像效果,两种方法观察到的样品表面结构差异明显.冷冻扫描电镜下的样品形态饱满、无塌陷皱缩,藻细胞表面的脊状凸起和水生植物叶片上的气孔结构清晰、无变形;而常规扫描电镜冷冻干燥的样品因脱水皱缩变形,甚至表面部分塌陷.冷冻扫描电镜可以有效地解决水生植物样品因脱水而皱缩变形的问题,最大程度地保持样品原本的细微结构特征,非常适合用于含水量高的水生植物样品的超微结构观察.%In this paper, the imaging effects of Cryo-scanning electron microscopy ( Cryo-SEM) and conventional scanning electron microscopy (SEM) on three kinds of aquatic plants (Coelastrella sp. , Wolffia and Hygrophila) were compared. The results show that there are obvious differences between the surface structures observed by the two methods. In Cryo-SEM images, the samples are plump without any collapses or shrinkages. The ridges of algal cells and the stomata on the leaves of aquatic plants are clear without distortion. In conventional SEM pictures, the freeze-dried samples shrink and part of the surface collapses due to dehydration. Cryo-SEM can effectively reduce the shrinkage and deformation of aquatic plant samples caused by dehydration. The original ultra-structures of samples are maximally maintained by Cryo-SEM. Therefore, Cryo-SEM is suitable for the observation of aquatic plants with high water content.