美洲黑杨维管形成层活动周期性及细胞超微结构的动态变化  

Periodicity of Vascular Cambial Activity and Dynamic Changes of Cell Ultrastructure in Populus deltoides

作　　者：尹增芳[1] 樊汝汶[1] 黄金生[1] 

机构地区：[1]南京林业大学森林资源与环境学院,江苏南京210037

出　　处：《南京林业大学学报（自然科学版）》2006年第6期1-6,共6页Journal of Nanjing Forestry University：Natural Sciences Edition

基　　金：国家自然科学基金重点项目(39730350);江苏省自然科学基金资助项目(BK2005132);南京林业大学"十五"人才基金项目(PG2004-2)

摘　　要：美洲黑杨维管形成层活动周期可分为休眠期、恢复活动期、活动期和转化期4个时期。休眠期维管形成层区约由3层细胞组成，细胞壁较厚，细胞内具有大量小液泡，其内包含一些电子密度较高的物质；细胞质内充满了游离的核糖核蛋白体，脂粒圆球形，散布在小液泡之间；内质网光滑型，多为短片状，只有近质膜处才呈网格状；线粒体内嵴不清晰，高尔基体数量较少，一般由3～5层扁平囊组成，周围未分泌形成高尔基小泡。恢复活动期维管形成层的细胞壁变薄，细胞内逐渐形成大液泡，内含物降解，细胞质的电子透明度增高。活动期维管形成层区细胞层数可达8～9层，细胞壁非常薄，细胞高度液泡化，细胞质和细胞核贴壁分布，或通过原生质索悬垂在细胞的某一位置，细胞器结构清晰，细胞质膜大量内折，与壁物质的形成有关。转化期维管形成层区细胞停止分裂，细胞壁逐渐增厚，液泡数日增多，体积减小，细胞开始积累淀粉、脂类和蛋白质等类物质。休眠期和活动期细胞超微结构特征相反，而恢复活动期与转化期细胞结构特征相似，互为可逆过程。The periodicity of vascular cambial activity in Populus deltoides could be divided into four stages： dormant, renewed active, active and transformed stages. In the dormant stage, the vascular cambium was composed of three layer cells. The cell had a thicker wall than the usual eambial cell, and also had a lot of small vesicles containing some substances that had higher electronic density. The dissociative ribsomes were abundant in the cytoplasm. Pellet-shaped lipid grains spread among the vesicles. Most of smooth endoplasm retieulum（SER） looked like short pieces in cell, but the SER was reticulated near the cell wall. The eristae of mitoehondria were not clear either. Usually, the Golgi body that was formed by 3-5 eisternaes was rare. There was no Golgi vesicle around the inactive Golgi body. In the renewed active stage, the eambial zone cell wall became much thinner, and the electronic density in cytoplasm was much lower because the substances involved in vacuole were disaggregated. In the active stage, the vascular cambial zone was composed of 7-8 layer cells. The cell wall was the thinnest one during the eambial activity period. At the same time, the cell was filled with vacuole mostly, and the cytoplasm and the nucleus were extruded beside the cell wall, or was overhang somewhere by cytoplasmic cable. The structure of organelle such as mitoehondria, Golgi body, endoplasm retieulum in the cell was complete. There were plenty of plasmalemma invaginations in the cell, which was related to cell wall substances accumulation. In the transformed stage, the mitosis of vascular eambial cell ceased,and the cell wall became thicken again. The volume of vacuole decreased, but the amount of vacuoles increased. Synchronously, starch, lipid and protein began to accumulate in the cell. During the periodicity of vascular cambial activity, the ultrastructural character of dormant stage was opposite to that of active stage completely. However, the ultrastructural character of the renewed active looked like that of the tra

关 键 词：美洲黑杨 维管形成层 周期性 超微结构 

分 类 号：S718[农业科学—林学]