觀音素心蘭子房發育與種子形成的研究

Abstract

本實驗自人工受粉後，利用石蠟切片，超薄切片及掃描式電子顯微鏡技術做觀音素心蘭(Cymbidium ensifolium)子房發育及種子形成之觀察研究。 自受粉成功後，胎座綠細胞開始分裂，進行增殖（10天有小卵型突起）。30天有胚珠原的形成，且可進行分芽現象。80天左右，大孢子母細胞開始行減數分裂，胚囊的發育屬於雙核型。120天左右，受精現象發生，極細胞受精後所形成的胚乳母核可進行核分裂，但最後消失。卵細胞與精核結合而成的接合子，則遲一至二月後方開始分裂。接合子可分裂成含胚管及胚軸的胚，外珠被細胞壁加厚後形成種皮在胚之外圍，種子的發育約在受粉後260天完成。

Self-pollinated cymbidiums were used as materials in this experiment. Ovary development and seed formation were observed with light microscopy and electron microscopies, TEM and SEM. After pollination, the margins of placenta region were proliferated actively. By 30 days, ovule primordia had formed. Later, it began budding dichrotomously. Megaspore mother cell was observed on 80 days, followed by bisporic megagametogenesis and eight-celled embryo sac formed. About 120 days, double fertilization occured. Endosperm mother nuclei divided without wall formation. The zygote gave rise to embryo with embryonal tubes and suspensor within seed over 260 days.