巴西香蕉幼苗对PEG-6000模拟干旱的生理响应(英文)

Physiological Responses of Brazil Banana Seedlings to Drought Stress Simulated by PEG-6000

[目的]探索巴西香蕉幼苗对PEG-6000模拟干旱的生理响应。[方法]以巴西香蕉(Musa AAA Cavendish subgroup cv.Brazil)幼苗为试验材料,利用PEG-6000人工模拟干旱胁迫环境,设3个胁迫强度处理(5%、10%、15%)和3个胁迫持续时间(24、48、72 h)研究干旱胁迫下巴西香蕉幼苗生理指标的变化。[结果]不同胁迫强度和胁迫持续时间处理的香蕉幼苗叶片相对含水量,叶绿素含量均显著下降幼苗叶片脯氨酸(Pro)含量表现为PEG15%>PEG10%>PEG5%,除PEG5%胁迫24 h处理与对照差异不显著外,其他处理均显著高于对照。幼苗叶片过氧化物酶POD活性表现为PEG15%>PEG10%>PEG5%,各处理POD活性均显著高于对照且各处理间差异显著,其中5%胁迫处理达最高。根系活力表现为PEG10%>PEG15%>PEG5%,PEG5%胁迫24、48、72 h处理均比对照显著增加,随后72h处理显著下降,24和48 h处理下降缓慢。[结论]可见,幼苗叶片相对含水量、叶绿色含量、Pro含量、POD活性和根系活力可以作为评价香蕉幼苗抗旱性的依据。

[Objective] The aim was to explore physiological responses of Brazil banana seedlings to drought stress simulated by PEG-6000.[Method] Brazil banana （Musa AAA Cavendish subgroup cv.Brazil） was taken as test materials to explore changes of physiological indices of banana seedlings under drought stresses simulated by PEG-6000,including three stress levels （5％,10％ and 15％） and time periods （24,48 and 72 h）.[Result] Relative water content and chlorophyll content both declined under different stress levels and in different times.The content of proline （Pro） in seedling leaves from high to low was PEG15％,PEG10％ and PEG5％; the content of treatment of 5％ stress in 24 h was of insignificant differences with that of the control and the contents in rest treatments were all remarkably higher compared with the control.POD activities of seedling leaves from high to low were as follows：PEG15％＞PEG10％＞PEG5％,and POD activity was of significant differences among treatments; POD activity achieved the peak in treatment group with 5％ of stress,and POD activities of different groups were all higher compared with the control.The activity of root system in treatment groups with PEG at different concentrations was as follows：PEG10％＞PEG15％＞PEG5％ and the activity increased remarkably in the group with PEG at 5％ within 24,48 and 72 h,though the activity dropped significantly within 72 h and slowly in 24 and 48 h.[Conclusion] It can be concluded that relative water content,chlorophyll content,Pro content and activity and root activity can be references of banana resistance to drought.