消落带植物南川柳对干旱胁迫的生理响应

Effects of Drought Stress and Recovery on Antioxidant Enzyme Activities of Salix rosthornii Seemen

为了探明消落带植物南川柳(Salixrosthornii Seemen)的耐旱特性,为消落带种群构建和植物选择提供理论依据,在盆栽条件下,对南川柳1年生幼苗采用控水方式进行干旱胁迫处理,同时设置对照组进行正常灌溉,并测定叶片相对含水量(RWC)、电解质渗漏(EL)、丙二醛(MDA)等一系列与植物耐旱能力相关的生理指标以及抗氧化性酶活性的变化,系统讨论了南川柳对干旱的生理响应。结果表明:在干旱胁迫下南川柳幼苗叶片具有较强的水分保持能力,并且在复水后有相对较快的恢复能力;10天和20天的干旱胁迫对南川柳叶片电解质渗漏的影响与对照相比差异不显著,随胁迫时间的持续,EL和MDA都显著升高。在干旱胁迫下,南川柳幼苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性整体呈先升高后降低的趋势,其中CAT对胁迫最为敏感,而POD响应相对较为缓慢;在复水20天后3种酶活性有所恢复,但均未恢复到对照的水平。

In order to ascertain the drought tolerant characteristics of fluctuating zone plants Nanchuan willow（Salix rosthornii Seemen）,and provide theoretical basis for fluctuating zone population structure and plant selection,a pot experiment was conducted on Nanchuan willow 1-year-old seedings under water control drought stress.Leaf relative water content（RWC）,electrolyte leakage（EL）,malondialdehyde（MDA） and a series of physiological indicators related to plant drought tolerance and resistance to oxidation activity changes were measured.The results indicated that：（1） Nanchuan willow seedling leaves had strong moisture retention capacity under drought stress and relatively fast recovery after re-watering;（2） 10 days and 20 days of drought stress had no significant effects on EL and MDA.With the continued drought stress,EL and MDA increased significantly;（3） the overall trend of superoxide dismutase（SOD）,peroxidase（POD） and catalase（CAT） activity under drought stress was first increased and then decreased.CAT was the most sensitive to drought stress,while POD was relatively insensitive.After re-watering 20 days,all three enzyme activities started to recovery,but not to the level of the control group.