Torus Structure and Development in the Woods of Ulmus Alata Michx., Celtis Laevigata Willd., and Celtis Occidentalis L.
Torus Structure and Development in the Woods of Ulmus Alata Michx., Celtis Laevigata Willd., and Celtis Occidentalis L.
复制标题
密西根州榆树、Laevigata Willd. 和西朴树树林中的环面结构和发育。
DOI：
10.1163/22941932-90001146
复制
发表时间：
1990
期刊：
影响因子：
1.9
通讯作者：
A. Rushing
中科院分区：
文献类型：
--
作者：
R. Dute;A. Rushing
榆阿拉塔、朴树和朴树的导管分子之间的纹孔膜通常含有托。环面的发展程度各不相同，在那些连接小直径元件的膜中最大。完整的环面由两个壁增厚相邻的中心层。在三维空间中，环面的形状通常近似于带槽的轮子。开始增厚的纹孔膜首先发生在一侧的老细胞和正在进行的次生壁合成开始之前。花托的形成是由于纹孔膜初生壁增厚所致。花托的发育与膜泡和池有关，但与桂花中报道的微管复合体无关。本研究中的小凹膜能够抽吸，并且环面可以防止在此过程中小凹膜破裂。
Pit membranes between tracheary elements of Ulmus alata, Celtis laevigata, and Celtis occidentalis often contained tori. The degree of development of tori varied and was greatest in those membranes connecting elements of small diameter. Complete tori consisted of two wall thickenings adjoined by a central layer. In three dimensions the shape of the torus often approximated a grooved wheel. Initiation of thickening in the pit membrane occurred first on the side of the older cell and was well underway prior to the beginning of secondary wall synthesis. Torus formation resulted from the thickening of the primary walls of the pit membrane. Development of the torus was associated with membranous vesicles and cisternae but not with microtubule complexes as was reported in Osmanthus. The pit membranes in this study are capable of aspiration, and the tori may prevent rupture of the pit membrane during this process.