作　　者： ; ; ; ; ;

机构地区： 华南农业大学林学院

出　　处： 《生态环境学报》 2009年第2期614-620,共7页

摘　　要： 以尾叶桉(Eucalyptus urophylla)和枫香(Liquidambar formosana)幼苗为试验材料,利用聚乙二醇6000(PEG-6000)人工模拟水分胁迫环境,设置三个胁迫强度处理(轻度胁迫、中度胁迫、重度胁迫)和三个胁迫持续时间处理(持续12h、24h、36h),研究幼苗叶片相对含水量、相对电导率、脯氨酸质量分数、叶绿素质量分数、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量和可溶性糖质量分数的变化,结果表明:经水分胁迫处理后,6种树种幼苗叶片相对含水量皆显现下降的趋势,水分胁迫处理12h的尾叶桉叶片相对含水量下降幅度小于枫香;随着水分胁迫强度的加深及持续时间的延长,2种树种幼苗叶片内相对电导率呈波动性上升的趋势;脯氨酸质量分数都有明显的增加,枫香叶片内脯氨酸质量分数的变化幅度大于尾叶桉叶片;苗木叶片叶绿素质量分数出现不规则波动;尾叶桉的SOD活性胁迫12h和24h时在中度胁迫达到最大,胁迫36h在轻度胁迫时达到高峰,而枫香的SOD活性经不同胁迫时间的胁迫处理后,在轻度胁迫时达到高峰;随胁迫强度的增加及胁迫时间的延长,尾叶桉叶片MDA含量有逐渐上升的趋势,枫香叶片MDA含量变化趋势表现为增加、下降、再增加;经水分胁迫处理12h时,随着水分胁迫强度的加剧,尾叶桉的可溶性糖质量分数显著增加,而枫香的可溶性糖质量分数在中度时下降,水分胁迫处理24h时2种苗木的可溶性糖质量分数波动,处理36h时轻度胁迫后下降。结果表明,叶片相对含水量、SOD活性和可溶性糖质量分数可以作为评价苗木抗旱性的依据,尾叶桉的抗旱能力大于枫香。 Studies on physiological changes of seedlings of Eucalyptus urophylla and Liquidambarformosana were conducted under drought stress using treatments of different PEG6000 concentrations （mild stress, moderate stress, severe stress） and different stress durations （12 hours, 24 hours, 36 hours）. The effect of the two seedlings to drought resistance was evaluated by testing relative water contents, relative conductivity, free proline, chlorophyll, super oxide dismutase （SOD） activities, contents of malondidehyde （MDA） and soluble sugar. The results showed that relative water content of the two seedlings decreased after being treated with drought stress, and the decrease degree for the E. urophylla was smaller than L. formosana when drought stress lasted 12 hours. With in- creasing stress intensity and prolonging duration, relative conductivity of the two seedlings tended to increase, their free praline greatly increased and chlorophyll fluctuated slightly. The activity of SOD of E. urophylla reached its maximum at moderate stress when drought stress lasted 12 or 24 hours and at mild stress when drought stress lasted 36 hours, and the activity of SOD of Lformosana reached its maximum at mild stress when drought stress lasted different time intervals. The content ofMDA ofE. urophylla tended to increase, whereas that ofL. formosana fluctuated. With increasing stress intensity and prolonging duration, soluble sugar of E. sylvestris increased whereas that of L. formosana increased initially and then decreased at moderate stress when drought stress lasted 12 hours, and that of the two seedlings fluctuated when drought stress lasted 24 hours and decreased at mild stress when drought stress lasted 36 hours. Relative water content, the activity of SOD and soluble sugar were proper physiological indices for evaluating drought resistance of the two seedlings, and drought resistance ofE. urophylla was stronger than L. formosana.

关 键 词： 尾叶桉 枫香 聚乙二醇 抗旱 生理指标

领　　域： [农业科学]