肉苁蓉(Cistanche deserticola Ma)种子的萌发及与寄主梭梭(Haloxylon ammodendron Bunge)的关系

在人工栽培条件下研究了专性寄生植物——肉苁蓉种子的形态解剖结构及其在寄主根上的萌发过程。肉苁蓉种子具有典型的列当科寄生植物种子的特征,种皮内仅有球形胚,外包以胚乳。根据观察发现,只有当寄主梭梭的根穿入肉苁蓉种子的种皮内且刺激其球形胚产生“芽管状器官”,并连接于寄主根上后种子才能萌发,与肉苁蓉种子连接的部位主要在根毛区。首先在与寄主根连接的“芽管状器官”的頂部膨大为瘤状物,以后在内部分化形成输导分子并与寄主的维管束相连通,进而在瘤状物远离寄主根的一端分化形成頂芽,由此长成肉苁蓉植株。

The Seed Germination of Cistanche deserticola Ma and It's Relationship with Host Plant Haloxylon ammodendron Bunge

The seed morphology and anatomy of obligate parasite-Cistanche deserticola Ma were studied by artifitial cultivation. The structure of the mature seeds is similar to that of the general root parasitic plants. The seed is tiny and contains a subglobose embryo that lacks differentiation into radicle, hypocotyl, cotyledons and plumule. Upon germination the morphological radicular pole of the embryo forms a "germ-tube-like organ". Its growing tip comes into contact with the root of the host and then penetrates into it and organizes the primary haustorium. The part that remains outside the host forms the "tubercle", This morphogenesis was obtained in several parasitic plants by experimental morphogenesis. The germination is dependent on a stimulus from the root of the host and shoot initiation did not occut unless contacted the root hair region of host. The process of germination of seeds of Cistanche deserticola can be used as a experimental model system for study of morphogenesis, metabolism of development. Nowadays we are working on these studies.