摘要
棉花(Gossypium hirsutum L.)小孢子发生过程中,细胞质超微结构发生显著而有规律的变化。这些变化主要涉及细胞质中核糖体、质体和线粒体。减数分裂前期Ⅰ,细胞质中核糖体密度逐渐降低,质体和线粒体结构变得不明显。粗线期至双线期,细胞质中核糖体密度降至极低水平,同时质体和线粒体呈衰退结构状态。中期Ⅰ,细胞质中核糖体恢复致密,质体和线粒体也恢复了正常的形态和结构。来自细胞核的类核仁进入细胞质并扩散。这是恢复中期Ⅰ细胞质中核糖体密度的主要原因。内质网在核糖体数量变化中显示出有重要作用。这些细胞质超微结构的变化可认为与世代转变有关。
Conspicuous cytoplasmic changes took place during the microsporogenesis of Cossypium hirsutum L. These changes mainly involved in the ribosomes, plastids and mitochondria. Du- ring meiotic prophase 1, the ribosome population of the cytoplasm diminished and reached to a minimum during pachytene——diplotene interval, and the membrane structures of both plastids and mitochondria turned unclear. In metaphase Ⅰ, cytoplasmic ribosome population restored to premeiotic level; plastids and mitochondria also regained their normal structures. The disin- tegration of nucleoloids from nucleus was the main mechanism for the restoration of ribosome population in metaphase Ⅰ cytoplasm. Endoplasmic reticulum may play an important role in the elimination and protection of part of cytoplasmic ribosomes during prophase Ⅰ. These obvious cytoplasmic changes are considered to be relevant to sporophyte-gametophyte transition.
基金
高等学校博士学科点专项科研基金
关键词
棉花
小孢子发生
细胞质
超微结构
Gossypium hirsutum
Microsporogenesis
Organelle
Cytoplasm reorganization
