红树植物地上根根端的发育,结构与生态适应

观察了分布于海南和广东省热带、亚热带海岸潮间带的６ 科９ 属１５ 种红树植物各种地上根根端与胚轴顶端的发育及结构。红树科（Ｒｈｉｚｏｐｈｏｒａｃｅａｅ）４ 属的支柱根根端，以显著的柱状分生组织区、根冠柱、栓质化的根冠为特征。老鼠簕属（Ａｃａｎｔｈｕｓ）、海榄雌属（Ａｖｉｃｅｎｎｉａ）的支柱根和海榄雌属、海桑属（Ｓｏｎｎｅｒａｔｉａ）的出水通气根根端都有短的根冠柱，薄的栓质化根冠或根冠的木栓层具有生长层。大多数红树植物的根端很早开始原形成层的活动，表皮之下常见外皮层，周皮常在表皮下层出现等独特的发育式样、结构特征，显示了环境的选择作用和红树植物的趋同适应

THE STUDIES ON THE DEVELOPMENT, STRUCTURE AND ECOLOGICAL ADAPTATION OF ABOVEGROUND ROOT APICES OF THE MANGROVE PLANTS

The aboveground root apices of 15 species of the mangrove plants have been observed. The species belong to 9 genera and 6 families, which are distributed in the intertidal region along tropical to subtropical coast in Hainan and Guangdong provinces. The histology of the prop root apices (aerial) of 4 genera of the Rhizophoraceae was characterized markedly by columnar meristematic area, columella and suberized sheath of root cap. The prop root apices (aerial) of Acanthus and Avicennia as well as pneumatophore apices of Avicennia and Sonneratia possessed short columella and thin suberized sheath, or showed growth layer in the phellem of root cap. Most of the mangrove plants started procambial activity very early.Under the epidermis exodermis usually and in the subepidermal layer periderm was developed. All these have shown the selectivity of environment and adaptive convergence in mangrove.