Comparative Structure Study On Salt Resistant Plants Living In Songnen Plain

Paraffin section technique and light microscopy were used to investigate the anatomy of the three species plants living in different environment in Changchun city and Baicheng city, including leaves, petioles, stems of Cornus alba L.,Acer mono Maxim, and Malus baccata(L.)Borkh. The results show that the plants living in Baicheng evolve various saline-alkai resistant structures.The leaves of C. alba living in Baicheng are thicker than those of C. alba in Changchun. There are many epidemic hairs and salt glands on epidermis of leaves. The epidermic cells are bigger than those of C. alba in Changchun. The palisade parechyma of leaves living in Baicheng evolve from 1 layer cells to 2 layer cells.Its petioles have big parenchyma cells and thick cuticle.Many salt glands are found on upper epidermis. Its stem has big epidermic cells, thick cuticle, many salt glands and big vessels. Many crystals are found in parenchyma cells. Different from other two plants, there are red materials in upper epidermis of leaves of the A. mono living in Baicheng and Changchun. The red materials may relate to the secretion of salt. In A. mono living in Baicheng ,there exist palisade parenchyma with 2 layers cells.The thick leaves have vein-parellel mesophyll cells. The crystals exist in parenchyma cells of its petioles. Its petioles have big vessels and much aerenchyma. There is clear pith ray in the stem, out of which there is thick cuticle. The marrow is smaller than that of C. alba in Changchun..M. baccata living in Baicheng have thick leaves and big epidermic cells, which palisade parenchyma is composed to 2 layer cells.Its leaves have aerenchyma and big vessel. Its petioles have big epidemic cells, stomata and substomatal chamber. There is similar palisade parenchyma under the epidemic cell, which is saline-alkali stress structure, which is adapt to the saline-alkali environment. The petioles have many protein-bearing cells and thicker cuticle. The stems have big epidermic cells, thick cuticle,big vessel and crystal. There are some tylosiser in vessel element. The shape of perimedullary zone and pith ray are clear.From the result above, conclusion can be draw as follow:every species plants can evolve different sanline-alkai resistant structure along the change of environment.In order to adapt to the different environment,they must have saline-alkali structure.The result effectively proves that three species plants living in saline-alkali environment Baicheng for adapting to saline-alkali stress ,evolve different saline-alkali stress structure.So they can live better in Baicheng.