The Comparative Structural Study On Three Species Of Salt-tolerant Plants In Songnen Plain

In this article light microscopy and paraffin-section technique were used to study comparative anatomical structure for Lycium chinense Mill. , Syringa oblata Lindl. and Syringa microphylla Diels. from two different habitat in Baicheng and Changchun. The results show that saline-alkali stress can induce plant to produce some morphological and structural changes of the plant, eventually it can adapt to this kind of environment and grows better. In this experiment, it is found that three kinds of plants can be induced to produce some adaptation to saline-alkali habitat of Baicheng with the same or different structural characteristic.Three kinds of plants show the improvement of assimilation ability by increasing number palisade cell layers and arraying more tightly under the saline-alkali habitat. The plant body tends to form great deal of aerenchyma under the saline-alkali habitat. The aerenchyma in three kinds of plants comes into being near the main vein and in spongy mesophyll of the leaf, in parenchyma tissue around of vascular bundle of the petiole, and in parenchyma tissue of cortex of the stem. Transport abilities of vascular bundles are improved, i.e. the diameter of vessel elements of three kinds of organs of L. chinense in Baicheng is obviously larger than those in Changchun; The diameter of the stem vessel element of S. oblata in Baicheng is larger than those in Changchun; about S. microphylla, the vessel elements diameter of the leaf and petiole in Baicheng is larger than ones in Changchun. Glandular cells are capable of secreting excess salts from plant organs. In S. oblate and S. microphylla, salt glands are discovered on surface of the leaf, petiole and stem, among them there are more on the leaf. Bladders are observed on petiole in L. chinense. The cells which contain ergastic substance such as crystal or protein can commonly be found near vascular bundles and parenchyma in all three kinds of plants.The cells of leaf epidermis of L. chinense are specialized and bubble-like. These changes can prevent plants from being losing too much water. The outer tangential cell walls of petiole epidermis cell of L. chinense in Baicheng produce well-proportioned finger-like protuberance which is thickened. The typical transfer cell have an extensive network of cell wall ingrowths of primary wall, they lie in the adjacent place of vascular bundle. They expand the interior area of the cell. L. chinense phloem periphery have one circle meristem-like tissue regularly arranged which are composed of 3-4 layers with having big nuclei and thick protoplasm, their tangential wall is 4 times length of radial wall. The author...