Ca-GA合剂和磷浸种对水分胁迫条件下冬小麦萌发及幼苗叶绿素荧光参数的影响

在干旱胁迫条件下 ,研究了钙赤合剂 (Ca -GA)和磷 (KH2 PO4 )浸种对冬小麦种子萌发及幼苗叶绿素荧光参数的影响。结果表明 :经Ca- GA处理和KH2 PO4 处理后的冬小麦种子萌发时α 淀粉酶活性显著升高 ,发芽势、发芽率均高于对照。幼苗的根冠比增大 ,叶片相对含水量增大。幼苗可变荧光 (Fv)、最大荧光 (Fm)、可变荧光与最大荧光比 (Fv/Fm)、可变荧光与初始荧光比 (Fv/Fo)、最大荧光与初始荧光比 (Fm/Fo)、光化学淬灭系数 (qP)在水分胁迫下降低幅度均小于对照 ;而初始荧光 (Fo)升高幅度小于对照 ,非光化学淬灭系数 (NPQ)升高幅度则大于对照 ,说明经Ca GA和KH2 PO4 处理可以减缓水分胁迫造成的光合电子传递、光合原初反应过程的抑制程度 ,提高光系统Ⅱ(PSⅡ)的电子传递和热耗散能力。实验结果表明 ,Ca- GA和KH2 PO4 浸种对促进冬小麦种子的萌发和提高幼苗的抗旱性有较大的帮助。

Effects of Ca-GA Mixture and Phosphorus on Chlorophyll Fluorescence Parameters

Effects of the mixture of calcium and gibberellin (Ca-GA) and potassium dihydrophaphate (KH_2PO_4) on chlorophyll fluorescence parameters of soaked winter wheat seeds during germination and young seedling under water stress condition were studied. The experimental results showed that Ca-GA treatment and KH_2PO_4 treatment markedly increase the activity and ability ofα-amylase during germination whereas root-shoot ratio and the relative water content (RWC) were increased in young seedling.The variable fluorescence (Fv), maximum fluorescence (Fm),the ratio of variable to maximum fluorescence (Fv/Fm), the ratio of variable to minimal fluorescence (Fv/Fo), the ratio of maximum fluorescence to minimal fluorescence(Fm/Fo) and the photochemical quenching (qP) decreased less;in contrast the minimal fluorescence (Fo) increased less than other treatments under water stress condition while non-photochemical quenching coefficient(NPQ)increased much than other treatments.Ca-GA mixture and KH_2PO_4 treatments could slow down the degree of inhibition of photosynthetic electron transport and photosynthetic primary reaction which caused by water stress,improved electron transport of PSⅡ and heat dissemination ability. So the drought resistance in winter wheat seed soaked with Ca-GA and KH_2PO_4 was increased during germination and young seedling.