丛枝菌根化香椿、秋枫幼苗对干旱胁迫生理响应

Physiological Responses to Drought Stress in Toona sinensis and Bischofia javanica Seedlings Colonized by Arbuscular Mycorrhizal Fungi

以香椿(Toona sinensis)、秋枫(Bischofia javanica)实生种子苗为试验材料,研究干旱胁迫下丛枝菌根化香椿、秋枫幼苗叶片质膜透性、游离脯氨酸含量及超氧化物歧化酶(SOD)活性的变化。结果表明:随着干旱胁迫程度加重及胁迫时间延长,香椿、秋枫幼苗叶片质膜透性、游离脯氨酸含量呈增加趋势,SOD活性在胁迫处理4天时明显增加,之后随着胁迫时间延长无明显变化趋势。中度干旱胁迫(田间持水量40%)处理20天时,菌根化香椿、秋枫幼苗叶片质膜透性、游离脯氨酸含量及SOD活性均高于非菌根化苗。这说明,接种丛枝菌根能有效促进香椿、秋枫幼苗生理抗旱性,且干旱胁迫程度越重效果越显著。

The leaf membrane permeability, free proline content and SOD activities were investigated in Toona sinensis and Bischofia javanica seedlings colonized by arbuscular mycorrhizal fungi under drought stress. Results showed that the leaf membrane permeability and free proline content in T. sinensis and B. javanica seedlings tended to be increased with the increasing intensity and duration of drought stress. For both species, SOD activities obviously increased under four-day drought stress, while the clear varia- tion for the activities was not be found with the increase of stress time. The leaf membrane permeability, free proline content as well as SOD activities in T. sinensis and B. javanica seedlings colonized by arbuscu- lar mycorrhizal fungi were higher compared with non-inoculation treatments after twenty days of mild drought stress （ field moisture capacity of 40% ）. This indicated that the physiological drought resistance in T. sinensis and B. javanica seedlings were able to be effectively improved by arbuscular mycorrhiza in- oculation, and the improvements were amplified by more serious drought stress.