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荒漠地区的胡杨(Populus euphratica)叶片为多态形,呈现出由披针形叶到锯齿卵圆形叶的规律性变化。为了研究胡杨异形叶的电子传递和光能吸收、分配和耗散对额济纳荒漠地区的适应特征,分别连续测定了生长季内胡杨两种典型叶片(披针形叶和锯齿卵圆形叶)的叶绿素荧光诱导动力学曲线。结果表明:(1)锯齿卵圆形叶的光系统Ⅱ(PSⅡ)原初光能转换效率(Fv/Fm)和PSⅡ的潜在活性(Fv/Fo)、光能利用参数(PI)高于披针形叶,QA的积累量(Vj)、QA还原的相对速率(Mo)小于披针形叶;(2)锯齿卵圆形叶的反应中心密度(RC/CSo)、单位横截面积上电子传递能量(ETo/CSo)高于披针形叶,单位横截面积上耗散的能量(DIo/CSo)以及单位反应中心上的能量流参数(ABS/RC、ETo/RC、TRo/RC、DIo/RC)低于披针形叶;(3)锯齿卵圆形叶用于光化学反应和电子传递的能量比例(ΦPo、Ψo、ΦEo)大于披针形叶,非光化学猝灭的最大量子产额(ΦDo)小于披针形叶。这说明,胡杨锯齿卵圆形叶相对披针形叶具有更有效的能量分配策略,对极端环境条件的适应性更强。
Populus euphratica leaves in desert regions are polymorphic and exhibit regular changes from lanceolate to serrated oval leaves. In order to study the electron transfer characteristics of Populus euphratica and the adaptation characteristics of light energy absorption, distribution and dissipation to Ejin desert regions, the chlorophyll contents of two typical leaves of Populus euphratica (lanceolate and serrated oval leaves) Fluorescence-induced kinetic curves. The results showed that: (1) The primary light energy conversion efficiency (Fv / Fm) and the potential activity of PSII (Fv / Fo) of photosystem II of serrated oval leaves were higher than those of lancets (2) The reaction center density of serrated oval leaves (RC / CSo), electron transfer per unit cross-sectional area (Vj), and the relative rate of reduction of QA (Mo) The energy (ETo / CSo) is higher than that of the lanceolate leaf, the energy dissipated per unit cross-sectional area (DIo / CSo) and the energy flow parameters per unit reaction center (ABS / RC, ETo / RC, TRo / RC, DIo / RC) is lower than that of the lanceolate leaves; (3) The energy ratio (ΦPo, ψo, ΦEo) of the serrated oval leaves for photochemical reaction and electron transfer is larger than that of the lanceolate leaves and the maximum quantum yield of non-photochemical quenching (ΦDo) smaller than lanceolate leaves. This shows that Populus euphorbia serrated oval leaves relative lanceolate leaf more effective energy allocation strategy, more adaptable to extreme environmental conditions.