摘要 | 中国鹅掌楸(Liriodendron Chinese (Hesml. ) Sarg)雄配子体发育的超微结构观察结果表明,中国鹅掌楸雄配子体的发育符合大多数被子植物的发育特征,表现在:1.小孢子核在萌发孔的相对侧靠近小孢子壁处进行有丝分裂,分裂末期形成细胞板,而后进一步发育形成分隔营养细胞和生殖细胞的纤维素的壁。2.胞质分裂极不均等,营养细胞与生殖细胞大小悬殊,而且生殖细胞内不含质体。3.生殖细胞在发育过程中发生一系列位移和形态变化,生殖细胞向营养核移动,与营养核贴合时,细胞核内染色质高度凝缩;与营养核分离后,生殖细胞纤维素的壁才完全解体消失,同时质膜凹陷,细胞呈不规则形态。4.营养细胞内脂质小泡极性分布,形成生殖细胞的脂体冠。5,营养核在与生殖细胞贴合过程中形状由近圆球形变为近弯月形,但核仁、核膜界限清晰,染色质始终保持均一状态。对生殖细胞分裂前的位置变化及其与营养细胞间的关系进行了初步的探讨。 |
Abstract | The ultrastructure observations on the features of the development of male gametophyte in Liriodendron Chinese was studied in detail. The results were shown as follows : 1. The mitosis of microspore nucleus takes place near the wall at the opposite side of germ spore. The cell plate formed in telophase of the first microsporic mitosis extended centrifugally until it connected with the intine of the pollen grain. A new wall was then formed to separated the generative and vegetative cells. 2. As the unequal cytokinesis, the generative cell was smaller than the vegetative cell, and it has no plastid. 3. At the process of development, the generative cell occurs a series of displacement and shape changes, and it can move to vegetative nucleus. The chromatin was contracted in the generative nucleus when it pressed close to vegetative nucleus. The generative cell wall didn't disapper completely until1 it was separated from vegetative nucleus. At the same time, the plasma membrane occurred hollow, and the cell took irregular shape. 4. The unequal distribution of lipid vesicle was very prominent in vegetative cell, which was detached from the intine of pollen grain, it was surrounded by the lipid vesicles called the corona of them. 5. During the development of male gametophyte, the shape of the vegetative nucleus changes similar globular into crescent moon-shaped, but the dividing line of nucleus and nuclear membrane was very clear, and the chromatin kept even state from beginning to end. |
关键词 | 中国鹅掌揪; 雄 配子体; 超微结构 |
Key words | Liriodendron Chinese; male gametophyte; ultrastructure |
作者 | 尹增芳 ,樊汝汉 |
所在单位 | 南京 林业 大 学 林 学 系 , 南京 2 1 0 0 3 7 |
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基金项目 | 国 家 自然 科 学 基 金 |