甘遂乳汁管的解剖学及营养器官中二萜类化合物分布的研究

Studies on anatomy of laticifers and localization of diterpene esters in vegetative organs in Euphorbia kansui

利用石蜡切片、半薄切片及组织化学的方法对甘遂各器官中乳汁管的类型、分布和大小进行了研究。结果表明,甘遂乳汁管为无节分枝型,在各器官中主要分布在维管束韧皮部的外侧或周围,此外,在根的中柱鞘薄壁细胞、叶片的叶肉组织、果实的中果皮及胚乳细胞内也有少量乳汁管的分布。甘遂乳汁管的大小在各器官中略有不同,其中茎中直径最大为39.79μm,块根中直径居中为36.90μm,叶肉组织中直径最小,仅有8.94μm;乳汁管的密度在其营养器官中差异较大,依次为叶>茎>根>块根。组织化学实验结果显示二萜类化合物在甘遂的营养器官中分布广泛。根中柱鞘和韧皮部的薄壁组织细胞,茎皮层、维管形成层和韧皮部的薄壁组织细胞,叶的叶肉细胞以及叶脉中的厚角组织和薄壁组织细胞的腔中都显示不同程度的红色,而乳汁管中乳汁的显色较深。

The type, distribution and size of laticifers in all organs of Euphorbia kansui were observed under light-microscope by the means of paraffin sectioning,semi-thin sectioning and histochemistry. The results were as follows： non-articulated branched laticifers were available in E. kansui. The laticifers were mainly distributed around the phloem of the vascular bundle,except that they were also distributed in the pericycle in root tuber, the mesophyll tissues in leaf, the mesocarp and endosperm in fruit. The size of laticifers in E. kansui varied slightly in different organs. The diameter of laticifers was largest （39. 79 μm） in stem,the medium （36. 90μm） in root tuber and the smallest （8. 94μm） in mesophyll tissues. However, the density of laticifers varied largely in different vegetative organs,whose descending order lists as leaf,stem,root and root tuber. Besides, histochemical results showed that the diterpene esters were distributed widely in the vegetative organs of E. kansui. The color showed by the cell cavity of latieifers was the darkest.