Study On Anatomy And Embryology Of Leptodermis Ordosica

This article take Leptodermis ordosica as the object of study. Through field investigation,outside observation, measure,light microscopy of paraffin-sectioned material and the electron microscope scanning technology. The article detailed systematically its vegetative organs and the reproductive organ anatomical structure , discussed the ecology biology characteristic and the structure foundation which survives in the arid barren environment in macroscopic, micro and ultramicro level. Furthermore, The research included microsporpgenesis, the development of male gametophyte, megasporogensis, The development of female gametophyte, fertilization, the development of embryo and endosperm of Leptodermis ordosica. Future directions for the theory of exploring survival mechanism, the reason and the structure which are in severe danger condition biology and the developmental of Leptodermis ordosica are also recommended. Conclusions as follows:Leptodermis ordosica reproducted primarily by the rhizome. And the seeds don't have dormant periods basically, time of viability is enough long to amount to above 3 years, the germination rate is high. This conclusion manifested its survival adaptation mechanism of reproduction way and the characteristic of seeds to adapt to of environment which are arid, few rain and barren; Anatomical structure of root, stems, leaves, rhizomes and flowers of Leptodermis ordosicahas have the obvious arid characteristic, which are the adaptability to the arid environment; The different long style indicated that the way of pollination was cross- pollination. Flower of Leptodermis ordosicahas has 5 stamens , each anther has 4 pollen sacs. The cytokinesis of microspore mother cell during meiosis is of simultaneaous type. Its tetrasporophyte is tetrahedral. The mature pollen grain (male gametophyte) is of 2-cell, and each has 3 germinal aperture. The development of anther wall follows the dicotyledonous type, composed of four layers, its tapetum is named as secretory tapetum. Ovary of Leptodermis ordosica is lower position, has 3~5 rooms, and each room have 1 ovule, axile placenta. thick nucellus type. The chalazal megaspore develops into functional megasporocyte. anembryo sac is of Polygonum type. Endosperm formation is belongs to nuclear type. Embryo development is of Chenopodiad type. When embryo is mature, it has the integrity seed leaf, the radicle, the hypocotyl and the plumule. The mature seed is integrity in structure.