关键词: 小麦, 大孢子母细胞, 减数分裂, 细胞质改组

Abstract: Ultrastructural changes of the megasporogenesis of Triticum aestivum L were studied. During the meiotic process of megasporocyte, the ribosome population diminished greatly in prophase I and restored in metaphase I; plastids and mitochondria turned unclear (dedifferentiation) in prophase I and recovered their normal structures (redifferentiation) in metaphase I. All these proved that cytoplasmic reorganization took place during the megasporogenesis of Triticum aestivum. It was also found that the nuclear envelope disappeared earlier at the micropylar end than that at the chalazal end. The speed of the programmed cell death were different in three nonfunctional megaspores at the micropylar end and their relationships with the neighboring cells were also different. The biological significance was discussed about these phenomenon.

Key words: Triticum aestivum, megasporocyte, meiosis, cytoplasmic reorganization