扁穗冰草营养器官的解剖学研究

A study on anatomy of vegetative organs of Agropyron cristatum

对扁穗冰草(Agropyron cristatum)的根、茎、叶及根茎等营养器官进行解剖学观察。结果表明,扁穗冰草各营养器官长期适应干旱的外部环境形成了特定的形态和结构:根的内皮层细胞形成马蹄形加厚,在紧靠内皮层的两层中皮层细胞有规则地排列成两环,但细胞壁未加厚;茎的表皮细胞排列紧密,角质层厚;叶上下表皮具有发达的角质层并密被表皮毛,具有发达的维管束,叶脉维管束鞘为典型的C3植物结构;根茎的构造由表皮、基本组织和维管束组成,近似于茎的构造,表皮无表皮毛或其他附属结构,维管束分布在基本组织内,其中近表皮层的维管束有规律的相对紧密的排成一环,内侧其他的维管束无规律的散布在基本组织内。

Anatomical observation was carried out on vegetative organs of Agropyron cristatum,including roots,stems,leaf and rhizomes,in this study.The results indicated that in order to adapt to a long-term external dry environment,the vegetative organs of A.cristatum formed drought-specific morphological structures.The walls of endodermal cells of roots were thickened and the cells showed horseshoe shapes.The cortex cells near the endodermis systematically arranged in two rings,but cell walls were not thickened.The epidermal cells of stems arranged compactly and were horny thickening.Upper and lower epidermal cells of leaves had ell-developed horny layers and vascular bundles;and the sheath of vascular bundles was a typical plant structure of C3.Rhizomes were consisted of epidermis,basic tissues and vascular bundles.The structure of rhizomes was similar to that of stems.The epidermal cells had no epidermal hairs and attachment structures.The vascular bundles distributed in the basic tissues,of which the vascular bundles near the epidermis arranged in a circle regularly but the others distributed irregularly.