沙葱(Allium mongolicum)解剖结构与抗旱性

The Relationship Between Drought-resistance and Anatomical Structure of Allium mongolicum's Vegetative Organs

解剖表明,沙葱(Allium mongolicum)根、茎、叶结构都具有抗旱性特征。根表皮细胞排列紧密,细胞壁加厚,皮层占根横切面90%以上,内有薄壁细胞,中柱占根横切面不足10%,与皮层比值大;初生木质部为四元型结构,无髓分化。茎由多层鳞茎片环形包裹形成,内部存在异常维管束,韧皮部内有厚壁组织,中央髓腔大,内实,贮水组织同型排列,维管束发达;表皮细胞角质膜厚,外向壁加厚;肉质鳞茎片由同型组织构成,薄壁组织和维管束分布其中。叶片表面被蜡质层,表皮角质层发达,细胞壁加厚,气孔下陷,具孔下室,数量多;肉质叶,栅栏组织发达,海绵组织不发达,中间髓腔大。

Through the observation of the anatomy of Allium mongolicum roots,stems and leaves by the Photomicrography camera,the results showed that the roots,stems and leaves of Allium mongolicum all have structural features of drought-resistance.The root epidermal cells tightly packed and cell wall thickened;cortex is more than 90% of root cross-section and parenchymal cells inside,the center pillar is less than 10% of the root cross-section,primary xylem is four haplotype structure and no marrow differentiation.The stem formed by a multi-layer bulb pieces with ring wrapped and abnormal vasculars inside,there are sclerenchyma in phloem,big central canal and full inside,the same type aqueous tissue arranged and vascular bundles developed,cuticular membrane and outgoing wall thickened;stem fleshy bulb composed by the same tissue,which parenchyma and vascular bundle distributed inside.Leaf surface covered with wax layer,the stratum corneum developed,the cell wall thickened and more stomatal subsidence with holes under the room;palisade tissue developed,spongy tissue undeveloped and big middle canal in fleshy leaves.These structural features of drought-resistance are great significance on surviving of Allium mongolicum in extreme drought environment.