Abstract: The two month old seedlings of 15 families of Casuarina equisetifolia were treated with different concentrations of polyethylene glycol-6000(PEG-6000) to study the changes of malondialdehyde (MDA), superoxide dismutase (SOD) activity and proline content. Results indicated that MDA content of seedling leaves of each family increased with the increase of stress intensity after drought stress treatment, but the increase rate of each family was quite different. The SOD activity of each family was different under different drought stress levels, and showed different capacity response to drought resistance. With the severe stress treatment, except the Yue-hybrid, the proline content of other families increased significantly compared with control. The comprehensive evaluation of drought resistance by principal component analysis showed that MDA content was the most important index reflecting water stress. Based on comprehensive analysis, the drought-resistance of 701, Pu2, Kang3, Hui2, Nanshan7, Dongshan2 were strong, the drought-resistance of Dongshanduan, 601, 59, A13 were middle, but the drought-resistance of Yue-hybrid, Kang1, Long4, Ping5 were weak.

Key words: Casuarina equisetifolia, PEG, drought stress, physiological index

摘要： 以木麻黄Casuarina equisetifolia 15个家系品种为材料，利用聚乙二醇6000(PEG-6000)模拟水分胁迫环境，设置三个胁迫强度处理(轻度、中度、重度胁迫)，研究受胁迫2月龄木麻黄幼苗丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、脯氨酸含量的变化。结果表明，经干旱胁迫处理后，各家系幼苗叶片MDA含量随胁迫强度增大而增大，但增幅差异较大；不同干旱胁迫水平下，各家系SOD活性存在一定差异；重度胁迫条件下，除粤杂交家系外，其余家系脯氨酸含量与对照相比均为显著增加。采用主成分分析法进行抗旱性综合评价，表明MDA含量是反映水分胁迫最重要的指标。各指标综合分析结果表明，家系701、莆20、抗3、惠2、南山7和东山2抗旱性能力较好；东山短、601、59、A13抗旱能力一般；千头、粤杂交、抗1、龙4和平5抗旱能力较差。

关键词: 木麻黄, PEG, 干旱胁迫, 生理指标