露草营养器官解剖结构

Study on Anatomical Structures of Vegetative Organs of Aptenia cordifolia

[目的]观察露草(Aptenia cordifolia)营养器官解剖结构,探讨其耐旱机理。[方法]采用石蜡切片法,在光学显微镜下观察露草根、茎、叶的解剖结构。[结果]根有一定的次生生长,产生周皮和次生维管组织,次生维管组织呈多轮分布。茎表皮单层细胞且外壁具角质层,皮层较厚且其中分布有散生维管束。叶为肥厚等面叶,上、下表皮分布有较密集的无规则型气孔器。[结论]露草根具周皮和次生维管组织,茎具角质层和厚的皮层、叶为等面叶等特征,与其抗旱性有关。露草的根、茎和叶中都分布有许多含针晶簇的细胞,茎、叶的表皮外均分布有许多盐囊泡,可能既是抗旱又是耐盐特征。

[ Objective ] The mechanism of drought tolerance of Aptenia cordifolia was explored through the observation of the anatomical structures of its vegetative organs. [ Method ] The structure of the root, stem and leaf of Aptenia cord^folia was observed under light microscope by means of themethod of paraffin section. [ Result ] The roots were with secondary growth of periderm and secondery vascular tissues. The secon- defy vascular tissues distributed in several rounds. The epidermis of the stems was of a single layer of cells and with a cuticle on its air surface, and the cortex was thicker with vascular bundles scattered insides. The leaves were fleshy thick and isobitateral with intense stomata of anomo- cytie type on their upper and lower epidermides. [ Conclusion] The characteristics were relative to drought tolerance such as the periderm and secondery vascular tissues of the roots, the cuticle on the surface and thicker cortex of the stems, and the isebitateral leaves. The rich crystal cells in the roots, stems and leaves, and many salt bladders on the epidermides of the stems and the leaves could hebong to drought and salt tolerance characteristics.