中文摘要：

铝毒害被认为是酸性土壤中限制植物生长的主要因子之一,试验以巨尾桉9号（Eucalyptus grandis×urophylla GLGU 9）组织培养苗为材料,探讨了5种外源酚酸（对羟基苯甲酸、香草酸、苯甲酸、阿魏酸和肉桂酸）对120 mg/L Al3＋胁迫下桉树幼苗生长状况及其抗氧化酶活性的影响。结果表明,在Al^3＋胁迫下,桉树幼苗的生长受到抑制,同时幼苗体内的超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、多酚氧化酶（PPO）活性和丙二醛（MDA）含量明显升高,而叶绿素含量降低;在加入外源酚酸后,桉树幼苗的叶绿素含量、CAT、PPO活性呈上升趋势,而SOD活性和MDA含量呈下降趋势。添加低浓度的外源酚酸后,铝胁迫得到明显缓解,可促进桉树幼苗的生长,均以10 mg/L的香草酸和苯甲酸处理的缓解效果最佳;高浓度的酚酸处理则抑制桉树幼苗的生长。

英文摘要：

Aluminium is one of the major factors to limit plant growth in acid soils. To investigate the impact of phenolic acids on the growth and antioxidant system of Eucalyptus grandis × urophylla GLGU 9 seedlings under aluminum stress, the treatments of five kinds of phenolic acids were conducted by adding P-hydroxybenzoic acid, Vanillic acid, Benzoic acid,Ferulaic acid, Cinnamic acid to the soils under 120 mg/L Al^3＋treatments. The results showed that, under aluminium stress,the growth of Eucalyptus seedlings was restrained; the activity of SOD, CAT, PPO and content of MDA were obviously increased; while chlorophyll content were reduced. After addition of phenolic acids, the physiological indices of Eucalyptus seedlings varied under different concentration. In total, the content of chlorophyll and the activity of CAT, PPO increased,but the activity of SOD and content of MDA decreased. The aluminum stress was significantly relieved by some acids at certain concentration as the treatments of low concentration promoted the growth of Eucalyptus seedlings. Vanillic acid and benzoic acid had the best alleviation effect to aluminum toxicity at the concentration of 10 mg/L.