Cytohistological observation of somatic embryogenesis in Aesculus hippocastanum L.

The origin and development of somatic embryos of Aesculus hippocastanum were observed by a paraffin method.The results showed that the embryonic cells had such characteristics as small and even size,dense kytoplasm,large karyon and obvious nucleolus as well as rapid division rate, while the non-embryonic cells had large size,small karyon,thin kytoplasm and much intercellular space and were not easy to agglomerate.The somatic embryogenesis mainly originated from surface unicells,and the regenerated plantlets were developed in turn as 2-cell proembryo,multicelluar proembryo, globular embryo,heart-shape embryo,torpedo-shape embryo and cotyledon embryo,being similar to a development process of zygotic embryo.The somatic embryos produced by in vitro culture had full-grown V-shaped vascular bundles,stem apex meristem and root tip meristem,possessing a distinct bipolarity and relative independence.