Five Woody Plant Evolution Structure

Light microscopy was used to investigate the anatomy of 5 species of salt-enduring plants living in different ecosystem in Baicheng city and Changchun city, including Pyrus vssuriensis Maxim., Prunus armeniaca L., Prunus salicina lindl. Ligustrum obtusifolium Sieb. Et Zucc., Sabina procumbens Iwata et Kusaka. The results show that the plants living in Baicheng city evolve various saline-alkali resistant structure.The plants have respectively some salt-resistant and alkali-resistant structural characters, epidermis with thick corticle, well-developed palisade tissue, and so on. There finds much interstitial space among cells of Pyrus vssuriensis Maxim, and Prunus salicina lindl. living in Baicheng city, the interstitial space forms after mesoglea of cell is dissolved, and turns into Aerenchyma. Oxygen that is inhaled from stoma is effectively reserved in the Aerenchyma, meets demand of plant. There doesn't find Aerenchyma among cells of Pyrus vssuriensis Maxim, and Prunus salicina lindl. living in Changchun city. It proves that the principle circumstance decides plant structure how to form is true. There are Saliferous vacuoplasts in epidermal cell and cortical cell of stem of P. vssuriensis Maxim, and in epidermal cell of stem of P. salicina lindl., they are both living in Baicheng city. The cuticle which has been secreted from protoplast wraps up the small saline vacuoles into small bags of vacuoles, salt ions that congregates in the Saliferous vacuoplasts isn't diffused to cytoplasm, so cells can avoid the damage from too much salt ions, various crystalloid exists in cells of Prunus armeniaca L. Prunus salicina lindl. Ligustrum obtusifolium Sieb. Et Zucc. living in Baicheng and Prunus armeniaca L. living in Changchun, crystalloid is inorganic salt that exists in vacuoplast. Forming crystalloid is antidotal response to saline-alkali stress.The structure effectively proves that saline-alkali stress leads to chang of botanic structure.