罗汉果营养器官的结构

1.罗汉果根、茎、叶的结构与葫芦科其它植物大致相似。不同之处有三方面:(1)叶子主脉中维管束为5个;(2)叶子中有硅质细胞成群分布;(3)块根具异常次生生长。在次生木质部中围绕导管形成形成层,由之分化出多个具韧皮部与木质部的小维管束。2.叶中的硅质细胞分布于表皮、栅栏组织、海绵组织中,多个细胞集合在一起。其细胞壁加厚并硅质化,细胞内容物消失。推测与增加叶子的支持力量有关。3.罗汉果雌株叶子上、下表皮气孔数之比为0.04,雄株为0.03,比值均很低,同时根据叶的解剖结构推测罗汉果为C_3植物。4.雌株叶子下表皮单位面积气孔数比雄株的多26％,差异很显著,值得进一步研究简化观察统计方法,以用于鉴别幼苗的性别。

THE STRUCTURE OF NUTRITIVE ORGANS IN SIRAITIA GROSVENORII

1. The structure of roots, stems and leaves in Siraitia grosvenorii is roughly similar to that in other plants of Cucurbitaceae. Differences in three repects are observed. ( a ) There are five vascular bundles in the midribs of the leaves; ( b ) There exist groups of silica cells in leaves; ( c ) The root tubers show anomalous secondary growth. In secondary xylem, a series of supernumerary cambia form around the tracheary elements. Many small vascular bundles with xylem and phloem differentiate from the supernumerary cambia. 2. In leaves, The groups of silica cells distribute in epidermis, palisade parenchyma and spongy tissue. Many silica cells gather to groups. Their walls become thickened and silicified and the contents of the cells disappear. It is inferred that the groups of silica cells relate to the increasing of the supporting force of leaves.3. The stoma ratio of upper/lower epidermis in female plants is 0.04, and in male plants is 0.03. These ratios are very low. From this point and from anatomical structure of leaf, it is inferred that this plnat belongs to C3 plants.4. The number of stoma per mm2 in lower epidermis of female plants is 26% more than that of the male plants. This difference is significant. It is worth simplifying the method of statistics to sex the seedlings.