Effects of Simulated Acid Rain on Physiological Characteristics of Musa basj oo and Canna indica Leaves | 模拟酸雨对芭蕉、美人蕉叶片生理特性的影响

chinois. 【目的】研究模拟酸雨对芭蕉、美人蕉叶片可见伤害及生理特性影响。【方法】在pH2．0、3．0、4．0、5．6（CK）6次胁迫后观测两种植物叶片的受害症状，测定它们的生理生化指标，分析其差异。【结果]pH2．0的酸雨胁迫对芭蕉叶片的伤害症状不明显，而美人蕉受伤害程度明显；美人蕉、芭蕉叶片MDA含量分别在pH≤4．0、pH≤3．0与对照的有极显著差异，且其较对照的增加幅度美人蕉大于芭蕉；随着处理次数的增加，芭蕉叶片SOD、POD和CAT活性与对照相比均有所升高，美人蕉叶片中POD活性有明显的升高趋势；对酸雨的抗性及耐受性存在明显差异，芭蕉强于美人蕉，美人蕉仅POD起到积极清除细胞内活性氧基团（ROS）的作用。【结论】pH≤3．0处理下，芭蕉对酸雨有较高的耐受性；美人蕉在酸雨胁迫下，活性氧的主要清除酶为POD，单一酶活性上升是美人蕉抗逆性差的主要原因。

anglais. [Objective] The objective of this study was to investigate the effects of simulated acid rain on visible damage and physiological traits of C. indica and M. basjoo leaves. [Method] This experiment had four pH treatments, including pH 2.0, 3.0, 4.0 and 5.6 （control）. Foliage dam- age was observed and malondialdehyde （MDA） content, superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） activities were analyzed after six stresses. [Results] Simulated acid rain of pH 2.0 had no significant influence on M. basjoo seedlings and no visible damage was ob- served. However, compared with M. basjoo, the injury symptoms in leaves of C. indica were much clearer. There were significant differences in MDA between treatments （pH 4.0 and pH 3.0） and control irrespective of the species and effect size was greater for C. indica relative to M. basjoo. Antioxidative enzymes activities （SOD, POD and CAT） of M. basjoo and POD of C. indi ca increased with treatment time. There was pronounced difference in resistance to acid rain stress between the two species. M. basjoo and C. indica had different resistance and adjusting mecha-nisms. M. basjoo had advantageous anti-active oxygen systems, which can scavenge free radicals effectively to avoid injuring membrane lipid. [Conclusion] M. basjoo had higher resistance to acidrain when pHi3.0. Under the acid rain stresses, the main removal enzyme of reactive oxygen species was only POD. Therefore, a single enzyme activity was increased by acid rain, which may be responsible for small resistance of C. indica.