Cytodifferentiation of the Seeds (Protocorms) and Vegetative Propagation Corms Colonized by Mycorrhizal Fungi

The stipecell, subepidermal parenchyma cells and inner cortical parenchyma cells were differentiated from Gastrodia elata Bl. seed and protocorm cells when they were colonized by the fungal hyphae of Mycena osmundicola Lange and M. orchidicola Fan et Guo. The hyphae aggregated in the suspensor remnant surrounding stipecell, primarily penetrated the stipecell, and then colonized the embryo of seed. Stipecell is the unique invading site of the hyphae. Subepidermal parenchyma cells containing pelotons of hyphae is also a kind of passage cells of hyphae, but, when primarily colonized by hyphae, they can degenerate a little of hyphae. The hyphae colonizing inner cortical parenchyma cells were totally degenerated, and the function of inner ocrtical parenchyma cells is digestive. The vegetative propagation corms, which differentiated from protocorms, were recolonized by Armilariella mellea (Vahl:Fr.) Karst., and the hyphae of A. mellea and M. osmundicola were found in the same cell, but there is a layer of cells uncolonized by mycorrhizal fungal hyphae. This means the two fungal species can not crisscross colonize the cell of G. elata.