Physiological Response Of Fraxinus Americana Linn. Under Water-Salt Stress

Two-year-old young trees of Fraxinus americana Linn. were used as material in this research. Through outdoor pot test, the changings in physiological characteristics of Fraxinus americana Linn. were studied, and preliminarily discussed the response under the water-salt stress and the growth effect. The paper of this research was to consul for the introduction and cultivation of Fraxinus americana Linn. in the coastal area of North China. Main results were as follows:1. Under the same salinity conditions or the same water condition, with the increase of soil salt content, growth condition of Fraxinus americana Linn. becomes worse, the leaf relative water content decreased, leaf soluble sugar content, relative conductivity gradually increased; soluble protein content, MDA content and SOD activity, POD activity and chlorophyll content without significant changes in the test.2. The Fraxinus americana Linn. will die in a short period of time when the soil salinity reaches or higher than 0.45%. The most soil moisture content adapt Fraxinus americana Linn. growth of soil field water holding capacity of 80%~90%.3. Under the condition of 0.15%-0.3% salt content the protective enzyme activity, total chlorophyll content relatively high with soil moisture conditions for 80%~90%. The soluble protein content and total chlorophyll in the stress process increased rapidly when the stress time 21d-28 d, and the stress response was obvious.4. Under continuous water-salt stress, the most suitable moisture conditions for Fraxinus americana Linn. is 80% ~ 90%, could eased the stress of 0.3% salt treatment in a certain extent.