摘要
用电子显微镜技术研究了巴西橡胶树(Hevea brasiliensis Mnll.Arg.)幼苗初生乳管分化的早期阶段,着重研究了乳管特有的结构成分的形成。最初可辨认的橡胶粒子出现在细胞质中,直径40—60nm,呈均匀的电子致密体;随着橡胶粒子的增大,粒子的中央区变为电子透明的,而周缘保持有电子致密物质,有时看到充满电子致密物的突起。观察到黄色体(本质为分散的溶酶体液泡)可由内质网膨大形成。在乳管发育过程中出现三种具有不同内含物的黄色体:最初的黄体含有染色很深的呈束状的微纤维,它们随后被含有浅色微纤维的黄色体所代替,成熟乳管的黄色体则含有杂乱的细纤维。在乳管分化初期,乳管细胞中不存在具有特殊结构的 F-w 复合体,只有许多与分生组织中的原质体相同的质体。观察到一些发育异常的乳管,它们似乎停留在发育的早期阶段,而不能继续发育成为典型的成熟乳管。
The early events of the differentiating laticifers in the primary system of the young shoot of Hevea brasiliensis were studied by electron microscopy with emphasis on the initiation of the characteristic components of the laticifer.The smallest rubber particles with diameter 40— 60 nm recognizable in the young laticifer appeared as electrondense globules in the cytoplasm and as the particles enlarge they became electron-transparent in their central region while the periphery of the particles remained electron-dense and one or more electron-dense protrusion (s) can sometimes be seen on the particles.Lutoids which constituted a dispersed lysosomai vacuole were found to origin from extensions of endoplasmic reticulum.There were three types of lutoids with different inclusions apperaring one after another in laticifer during its deve- lopment.The lutoids with dark microfibrils appeared first,then replaced by the lutoid with bright microfibrils and in mature laticifer only the lutoids with fine fibrils were able to be found.There were no F-W complexes but normal proplastids in laticifer at the initial stage of its development.Some abnormal laticifers were detected that appered to remain in early stage of differentiation and did not form typical ones.
基金
国家自然科学基金
关键词
巴西橡胶树
乳管
分化
超微结构
Hevea brasiliensis
Laticifer
Differentiation
Ultrastructure
