Abstract: To explore the growth,physiological and biochemical characteristics of Quercus acutissima under water stress,one-year-old seedlings of Quercus acutissima were subjected to four levels of soil water stress.Results indicated that the relative growth,relative ground diameter growth,relative crown width and biomass increment of Quercus acutissima seedlings decreased with increase in water stress.However,the biomass increment did not change significantly between W2,W3 and W4 treatments.The content of free proline,soluble sugar,malondialdehyde(MDA),soluble protein and relative lipid membrane permeability in leaves increased with the decrease in soil moisture content.The activities of the protective enzymes superoxide dismutase (SOD),peroxidase (POD)and catalase (CAT) increased at first,but their activities decreased when soil moisture content reached 25% of field capacity.With increase in water stress,seedlings of Quercus acutissima can reduce the damage caused by increasing root-shoot ratio and protective enzyme activity.

Key words: Water stress;Quercus acutissima;Growth;Physiological and biochemical characteristics