芒秆皮层的SEM-EDXA研究(Ⅱ)

Study on the Cuticle of Miscanthus Stem by Means of SEM-EDXA(part Ⅱ)

用SEM-EDXA法研究芒秆叶鞘皮层的形态、超微结构及Si等矿质元素的分布。结果表明,叶鞘外表面皮层由颗粒物纵向规则排列区域和分散分布区域交替排列而成;每个颗粒物组由两个相对的“肾型”颗粒物纵向排列而成。与外表面皮层两种形态区域对应,皮层横切面由致密区域和疏松区域交替排列而成;致密区域的厚度大且质地较均一,Si元素的含量低,其内部主要是维管束组织;疏松区域的厚度小,Si元素的含量高,其内部则主要是近乎圆形的空腔。叶鞘皮层主要含C、O、Si、Cl、K、Ca等元素,C元素的含量低;外表面皮层的Si含量约为50%,内表面皮层的Si元素含量仅4%左右;叶鞘外表面皮层中的Si化合物主要是无机物。

The morphologies and ultra-structure of the cuticle of Miseanthus stem and the distribution of mineral elements in it were studied by means of SEM-EDXA. The results showed that the outer-surface of the stern cuticle consists of two different regions alternatively, one with longitudinally parallel strips, and the other with non-strlp. The longitudinal sections are porous and there are some transversally tubular porosities with laminated cell wall. The silicides in the stem cuticle have different forms of crystalline. The morphologies and ultra-structure of the cuticle of Miseanthus stem are obvionslv distinct from that of sugarcane and wheat stem. The cuticle mainly contains four chemical elements, i.e. C, O, Si and K, the Si content is more than fifty percent, the C content is less than four percent. The Si content in the middle-part of the cuticle is the highest, and that in outer or inner-part of the cuticle is slightly lower. The Si content in the fiber underneath the epidermis or in the inner organs of the stem is 0.00%. It is obvious that the Si element plays a key role in the Miseanthns stem cuticle, and most of silicides in the cuticle will be inorganic in nature. It is to effectivel.v remove the Miscanthus stem cuticle for the substantially decreasing the silicon in black liquor of alkaline Miseanthus pulping.