水稻癒合組織的假導管形成

Tracheary Formation in Rice Calli

源自水稻（Oryza sativa）幼苗癒合組織經繼代培養於含有2ppm 2, 4-dichlorophenoxyacetic 和1ppm kinetin的MS培養基上，則會最有效地產生細小而質硬的白色癒合組織。此組織內含百分之八的假導管，分別以分枝狀、團狀及帶狀存在。超微結構顯示假導管細胞內分化過程中有胞器逐一退化及細胞壁的不均勻加厚現象，成熟的假導管內主含明顯及不均勻細胞壁加厚的次生細胞壁及一些初生細胞壁的遺跡。

Calli induced from seedlings or rice (Oryza sativa) were subcultured in MS medium containing different tested plant growth hormones. The combination treatment or2 ppm 2,4-dichlorophenoxyacetic acid and 1 ppm kinetin is most effective in production of tiny, white and hard calli, which contain 8% cells being tracheary elements in shapes of fork, nodule and band. Ultrastructural studies show the appearance of gradually degenerated organelles and unevenly wall-thickening occurring in differentiating tracheary elements. Mature tracheids contain only cell wall with distinct and unevenly thickened secondary wall, and partially remained primary wall.