Structral Comparison Of Nerium Imdicum Mill. In Different Ecological Environmnets

In this paper, xylotomy, dispersing of vessel elements, paraffin-section technique and light microscopy photography were used to study on anatomical structure features and drought tolerance of young stem, leaves, petiole and branch wood of Nerium imdicum Mill. lived in different ecological environments to explore the anatomy of N. imdicum Mill. and growth characteristics of the relationship between the environment and the adaptability to different ecological environments.For the same plant, there were some differences on the anatomical structure of plants in relative arid or humid environment. Research for this article N. imdicum Mill., the selected structure are the following: branch wood, the young stems, petioles and leaves of the structural features, and these structural features given in a number .Comparison of the growth in a different environment with N. imdicum Mill. branch-woods of structure analysis, it chosed single-ray tube aperture height and width and vessel pore diameter which amount to three structural parameters to make measure; in leaf, it selected of leaf blade thickness, stratum corneum thickness, palisade tissue, spongy tissue, the ratio of palisade parenchyma thickness to spongy parenchyma thickness, radial diameter of costate vessel amount to seven structural parameters as drought-resistance guide line to make measure; in petiole, cuticular layer thickness of epidermis cell and epidermis cell thickness and radial diameter of xylem vessel were chosen to be scaled. by variance analysis, the result reveals that all kinds of structural parameters have mighty discrepancy except costate vessel radial diameter and branch-woods single-ray tube aperture height that is not remarkable difference.The results show that the growth of N. imdicum Mill.in the campus of Northeast Normal University has thicker leaves, densely epidermal hair, developed cuticle, high ratio of palisade tissue to spongy tissue and well-developed main vein vascular bundle than the Japonic ones; petiole epidermal slice thickness, xylem radial diameter; young stems and leaves appear aerenchyma. In the campus of Tsukuba University, N. imdicum Mill's corresponding parameters is not obvious, which fully shows the morphology of plant organs is closely related to its growth environment. .The experiment also presented the evolution characteristics and regularity of N. imdicum Mill. growing in different ecological environment.