科研之友
微信
新浪微博
Facebook
分享链接
摘要
The Brazilian Atlantic Forest is a biodiversity hotspot. Many Bromeliaceae species are important components of this biome, including endemic plants, such as Dyckia pseudococcinea. However, human pressure has resulted in its designation as threatened with extinction. In an attempt to encourage the establishment of subsidised support for in vitro culture protocols that ensure its reproduction, the embryo development of this species was examined by light microscopy. Embryo development initiates with the sporophytic zygote, which undergoes a first cell division that is asymmetrical and transversal. A polarised bicellular proembryo is then formed, with an apical and a basal cell that contribute to the subsequent stages of an Asteraceae-type embryogenesis after successive divisions. Differentiation of the peripheral cells is observed during the post-octant proembryo stage that gives rise to the protoderm. At maturity, the embryo is composed of a cotyledon, shoot and root apical meristems, and a suspensor. The polarisation of the bicellular proembryo and the establishment of the protoderm were identified as the two critical stages in the embryonic development of D. pseudococcinea. Thus, in vitro propagation efforts to produce seedling plants should use proembryos from the tricellular to octant stages in view of their capacity to follow distinct morphogenetic pathways.
- 出版日期2010
