Embryology of Phalaenopsis amabilis Var. formosa: Embryo Development

台灣蝴蝶蘭的胚發育

李勇毅(Yung-I Lee) ； Edward C. Yeung ； 李哖(Nean Lee) ； 鐘美珠(Mei-Chu Chung)

《Botanical Studies》 49卷2期 (2008/04) Pp. 139-146

摘要

台灣蝴蝶蘭(Phalaenopsis amabilis var. formosa)為原生於台東和蘭嶼的著生類蘭花。在受精完成後，接合子連續進行兩次細胞分裂產生一個⊥形的四細胞胚。緊接著，此四細胞胚中接近珠孔端的兩個細胞擴增體積，並且進行兩次細胞分裂，形成八個管狀的胚柄細胞。這些管狀的胚柄細胞呈現高度的液胞化，向下擴展延伸至近珠孔端，向上則到達合點端。在胚發育早期，在胚柄細胞內可觀察到脂質體形成，在後續的發育階段則消失。因此胚柄在胚胎發育過程中擔任養分吸收的角色，並提供暫時的存放空間。當種子成熟時，可觀察到胚體頂部有一群分化程度較高的細胞。台灣蝴蝶蘭的胚體細胞內主要的儲藏物質為蛋白質體與脂質體。由尼羅紅(Nile red)染色所散發的螢光顯示：角質層只累積於胚體的表層細胞壁中，在胚柄的細胞壁中並無累積。在種子成熟時，角質亦累積於種皮的最外層細胞壁。

關鍵字

胚 ； 蘭花 ； 台灣蝴蝶蘭 ； 胚柄

並列摘要

Phalaenopsis amabilis var. formosa is an endemic epiphytic orchid variety native to Taitung and Lanyu of Taiwan. A ⊥-shaped, four-celled embryo is produced by two successive cell divisions of a zygote. Soon after, two of the four cells toward the micropyle enlarge and divide two more times resulting in the formation of eight tubular suspensor cells. The suspensor cells are highly vacuolated; the bottom tier of suspensor cells elongates towards the micropyle, and the upper tier elongates towards the chalazal end of the seed. During the early stages of embryo development, lipid droplets appear in the elongating suspensor cells and disappear soon afterwards, indicating the suspensor functions in nutrient uptake and as a temporary food storage site for the developing embryo. In the mature seed, a differentiated apical zone containing the relatively small cells can be seen in the embryo proper. Protein and lipid bodies are the main storage products in the embryo proper cells. The results of Nile red staining indicate that a cuticular layer is present only on the surface walls of the embryo proper, but is absent from the suspensor cell wall Cuticular material is also present in the outermost layer of the seed coat and persists through seed maturation.

並列關鍵字

Embryo ； Orchid ； Phalaenopsis amabilis var. formosa ； Suspensor