新疆北部早春短命植物鸟头荠营养器官解剖学研究

An Anatomical Study on the Vegetative Organs of Euclidium Syriacum ( L. ) R.Br.Spring Ephemeralin Northern Xinjiang

文章采用石蜡切片法,观察到十字花科短命植物鸟头荠〔Euclidium syriacum(L.)R.Br.〕的根、茎、叶有适应特殊环境的结构特点,其结果表明鸟头荠有中生植物结构特点。它的根系分布在土壤的表层。根的次生木质部导管直径大。根、茎、叶中都有大型的薄壁细胞。茎、叶表皮细胞外壁有角质层,叶的表皮细胞还有表皮毛和腺毛,叶表皮气孔多,栅栏组织发达,其维管束围有一层维管束细胞,内含较多叶绿体,为C4植物型。综上所述,鸟头荠的根、茎、叶的结构虽然有一些旱生特点,但总体上看,仍然属于典型的中生植物。鸟头荠是一种结构简单,生长发育快,光合效率高,具有一定的耐旱性中生结构特点的一年生短命植物。因此可以断定,一年生早春短命植物对干旱环境的适应是内部结构的特化,而更重要的是利用其特殊的生理特性和短的生活周期来完成的。因此早春短命植物鸟头荠是干旱植被中一类特殊的草本植物。

In this study, using paraffin section method, we observed roots, stems and leaves of crucif- erous ephemeral Euclidiurn syriacum （L.） R. Br. had the structural characteristics to adapt to special cir- cumstances, the results showed that the Euclidium syriacum （L.） R. Br. had structural characteristics of mesophyte. Its root distributed in the soil surface. Diameter of root secondary xylem was large. Roots, stems and leaves all had large thin--walled cells. There existed cuticle outside of stem, leaf＇s epidermal cells. Epidermal cells of leaf also hadtrichomes and glandular hairs, with many stomas, palisade tissue was developed,moreover,there were vascular bundle cells around the vascular bundle, containing a lot of chlo- roplasts inside, it was the C4 plant type. In summary said, although the root, stem, leaf of Euclidium syr- iacurn （L.） R. Br. had some xerophytic structural characteristics, in all, it was typical of the mesophyte. Euclidiurn syriacum （L.） R. Br. was short--lived annual plants which had structural characteristics of drought tolerance, it also had simple structure, fast growth and high photosynthetic efficiency. So it can be concluded that short--lived annual plant＇s adeptation to drought environment was specialization of internal structure, while what＇s important is that its accomplishment depended on its special physiology and short life cycle. Socruciferous ephemeral Euclidium syriacurn （L.） R. Br. was a special class of herbs in dry veg- etation.