芡繁殖器官的形态结构及其生态适应研究

芡萼片宿存,花瓣3—6轮,外轮雄蕊片状,不育,子房陷于花托之内,为片状胎座。传粉方式有自花传粉、昆虫传粉、闭花传粉三种。果实由三层果皮组成,表皮层有腺毛及粘液;中果皮较厚,成海绵组织,并分布有星芒状石细胞和维管束;内果皮只一层细胞,成熟果实分泌毛脱落,果柄柔软,果实下垂,可作为适时采收的指标。芡花和果实中存在的多酚氧化酶和细胞色素氧化酶以及丹宁等物质,对芡花和果实有保护作用。芡种子的种皮共有四层,成熟后坚硬,种皮外有假种皮,有增加浮力的作用。胚乳较早解体,由外胚乳作为养分的主要贮备场所。种子须在水中进行后熟,使胚体充分成熟,否则幼胚因失水而丧失萌发能力。文章探讨了花粉败育的原因和弥补措施。芡花和果实的结构、种子散布和传粉方式,说明了对水生环境的适应性及其与其他睡莲科植物的亲缘关系上存在的联系。

STUDIES ON THE MORPHOLOGY AND ANATOMY OF THE REPRODUCTIVE ORGANS OF EURYALE FEROX SALISB AND ITS ECOLOGICAL ATAPTATION

The calyx of the flower is persistent with its petala arrange in 3-6 whorls. Stamens of the outer whorl are in triangular lamellate form which are sterile in nature. Ovary is imbeded in the center of receptacle, placentation is laminal, Three forms of pollination are observed, namely: self-pollination (autogamy), cleistogamy and pollination by insecte (entomophily), Pericarp of the fruit is made of three parts, with glandular hairs cover its epidermal layer. Mesocarp is thick with cells loosely arranged in the form of spongy tissue, sclereids of branched form and vascular bundles are distributed throughout this layer. Endocarp consists cells of one layer only. As the fruit becomes matured, the epidermis sheds off its glandular hairs, pedicel becomes softened and the fruit is pendent into the water which indicates that it is the time for fruit collection. Distribution of polypenol oxidase, cytochrome oxidase and tannin material are detected in the flower and fruit for protection. Testa of seed consists of four layers which becomes hard and woody after ripening. The presence of aril outside the testa may increase the buoyancy of the fruit. Endosperm degenerates early in its development, food supply for young embryo development is stored mainly in the thick perisperm. A period of after-ripening is necessary before germination, and hence seeds must be stored in water after harvesting. Causes of pollen abortion are studied in this paper. The structure of flower and fruit, its method of seed dispersal and forms of pollination show evidently that all these characteristics are adaptational to water environment, and the plant is quite related to other members of the family Nymphaceae.