低温对蝴蝶兰胚珠发育的影响

The Effects of Low Temperature on Ovule Development of Phalaenopsis

摘要:

低温(12-18℃)处理的蝴蝶兰,授粉50d开始分化胚珠原基、60 d胚囊处于大孢子母细胞时期,比常温(20-25℃)下的推迟10-15 d；授粉70 d,常温下的蝴蝶兰植株已完成雌配子体发育和双受精,而低温处理的蝴蝶兰仍未完成大孢子的发生过程。低温处理的蝴蝶兰,胚囊发育过程中珠心细胞提前退化,在大孢子母细胞外围形成较厚的胚囊壁。胚囊只发育到单核胚囊阶段,没有形成成熟胚囊。

Abstract:

The differentiation of ovule primordium of a hybrid of Phalaenopsis initiated at low temperature (12-18℃) 50 days after pollination, and megasporogenesis appeared 60 days after pollination. The megasporogenesis at normal temperature (20-25℃) was delayed for 10-15 days. Although the megagametophyte formed and even the double fertilization had been finished 70 days after pollination at normal temperature, the megasporogenesis had not yet been finished at low temperature. Nucellar cells degenerated in advance under low temperature, which resulted in thickened embryo sac wall surrounding the megasporocyte. The embryo sac developed into functional megaspores only and no mature embryo sac was generated.