高等海洋植物海神草营养器官的组织学特点

采用常规石蜡切片法,对海神草(Cymodocea rotundata)营养器官的组织学进行研究。结果表明:海神草的根、茎、叶均具有发达的通气组织,根由表皮、皮层和维管柱三部分组成,内皮层中有凯氏带且六面加厚结构。茎由表皮、基本组织和维管组织三部分组成,维管组织有1束中央维管束和数束外环维管束,维管束为有限外韧维管束,有气隙分布。叶由表皮、叶肉和叶脉三部分组成,上下表皮均由单层细胞构成,排列规则无胞间隙,其外壁覆盖一层连续的角质层,无气孔但分布有类泡状细胞,表皮细胞中富含叶绿体,是光合作用的主要部位。本文还讨论了海神草营养器官与海洋沉水生活相适应的结构特征。

Histological characteristics of the vegetative organs in Cymodocea rotundata

The histological characteristics of the vegetative organs in Cymodocea rotundata were studied using the traditional paraffin wax sections method. The results showed that the vegetative organs have developed aerenchyma tissues. The roots can be divided into three parts called the epidermis, cortex, and vascular tissue from outside to inside. The endodermis has a Casparian strip and six thickened structures. The stem can be divided into the epidermis, the basic organization, and vascular tissue. Within the stem there is one beam of a central vascular bundle and some outer vascular bundles. The leaves can be divided into the epidermis, the mesophylls, and the veins. Both the upper and lower epidermal cells are uniseriate. The epidermal cells have a regular column shape with no intercellular spaces. Their outer walls are thickened and the surface of the outer walls are covered with continuous cutin. Bulliform-like cells but no stomas were found in the epidermis. The chloroplasts in the epidermal cells are numerous and extensive, and the epidermal cells are the main place for photosynthetic reactions. The anatomical characteristics mentioned above are a result of environmental adaptations.