水分胁迫及复水对虉草生理生化特性的影响

Effect of water stress and rewatering on the physiological and biochemical characteristics of Phalaris arundinacea

通过温室盆栽控水试验,研究了虉草在自然干旱与复水过程中生理生化指标的变化规律,旨在探讨虉草对于水分变化的响应特性及耐旱能力。结果显示,1)干旱胁迫期间,尽管土壤含水量下降迅速,但是叶片相对含水量在水分胁迫前8d仍维持在正常水平,直到第12天时才显著下降。2)在持续干旱过程中,可溶性蛋白与丙二醛含量不断增加。3)叶绿素、叶绿素a、类胡萝卜素含量及Chla/Chlb与Car/Chl的比值整体上均随干旱胁迫时间的延长而呈上升趋势。4)干旱胁迫后期,叶绿素荧光参数Fo、NPQ增加,Fm、Fv/Fm、Fv/Fo与qP均有所下降。5)复水后,各指标均能迅速得到不同程度恢复。研究结果初步表明,虉草具备较强的保护与损伤修复能力,使其能够适应较大程度的干旱逆境。

To investigate the responsive mechanisms and drought resistance of Phalaris arundinacea, the chan- ges of physiological and biochemical indicators were studied over a long time, using pot-cultures under continu- ous artificial water stress conditions in a greenhouse. 1） During drought stress, the soil water content declined rapidly but the relative water content of leaves was not significantly reduced and was maintained at a normal level until the 12th day of drought. 2） In the process of drought stress, the soluble protein and malondialde- hyde （MDA） contents increased continuously. 3） On the whole the contents of chlorophyll （Chl）, chlorophyl a （Chla）, carotenoid （Car） and the ratio of Chla/Chlb, Car/Chl all increased with the duration of prolonged drought. 4） In the late stages of drought stress, the chlorophyll fluorescence parameters of minimal fluores- cence （Fo） and the non-photochemical quenching coefficient （NPQ） increased, while the maximal fluorescence （Fm）, maximal quantum yield of PS Ⅱ （Fv/Fm）, potential activities of PS U （Fv/Fo） and photochemical quenching coefficient （qP） all decreased. 5） All the indicators were quickly restored to different degrees after rewatering. All these preliminarily results indicate that P. arundinacea has strong protection and damage re- pair capabilities which enable it to adapt to a high degrees of drought stress.