Effect of Soil Water Stress on the Growth and Eco-physiological Characteristics of Eucalyptus Seedling

Pot culture experiments were conducted to examine the eco-physiological characteristics of Encalyptus urphylla cv U_6 seedling. The seedling was grown under four different soil relative moistures, e. g., 100%(Ⅰ,CK),80%(Ⅱ),60%(Ⅲ)and 40%(Ⅳ) of field water-holding capacity. The results indicated that the growth of height, stem, root, leaf number, leaf area and biomass of seedling was influenced significantly under soil drought stress, but the influence to the growth of leaf was more higher than that of root and stem. And all values of above decreased with the soil drought stress developing. Soil drought stress also affected the leaf water content , chlorophyll content and free proline content of seedling significantly. When the soil relative water deficit was severe, both leaf water content and chlorophyll content decreased significantly, but free proline content increased evidently. The relation between free proline content accumulation and drought-resistance was needed for further study to be concluded.