Effects of Low Temperature Stress on Some Physiological Changes of Acacia auriculaeformis and A. mangium

Under low temperature stress, the contents of the soluble sugar, the soluble protein and the free proline changed significantly. And there are significant correlation between them and the treatment temperature. The specific activity of SOD decreased at first and then increased in the whole. The content of MDA firstly increased, then decreased, and finally increased again. The cold resistance of seedlings of A. mangium was increased by pretreatment with abscisic acid. The result showed that the pretreatment of either 10-4 mol·L-1 ABA foR24 hours or 10-5 mol·L-1 ABA for 36 hours was the optimum treatments to improve plant cold resistance.