持续干旱对油棕幼苗叶绿素荧光动力学参数的影响

为研究持续干旱对油棕叶绿素荧光动力学参数的影响，以油棕2 年生幼苗为试验材料，采用盆栽方式模拟自然持续干旱，测定叶绿素荧光参数及叶绿素含量，并运用隶属函数法对其抗旱性进行综合分析。结果表明：干旱胁迫下，油棕叶片叶绿素含量、可变荧光(Fv)、最大荧光(Fm)、可变荧光与最大荧光比(Fv/Fm)均降低；初始荧光(F0)和非光化学淬灭系数(NPQ)则升高，说明干旱胁迫伤害了光系统Ⅱ(PSⅡ)，使得PSⅡ原初光能转换效率(Fv/Fm)降低，光合电子传递、光合原初反应过程受到抑制，起光保护作用的热耗散(NPQ)提高。4 个品种的叶绿素荧光参数和叶绿素含量的变化存在品种间差异，整个处理过中对干旱的适应性‘热油6号’＞‘热油8号’＞‘热油2号’＞‘热油4号’，因此，叶绿素荧光参数和叶绿素含量可作为抗旱性强弱的诊断指标用于油棕抗旱育种及相关研究。

Effect of Persistent Drought Stress on Chlorophyll Fluorescence Parameters in Leaves of Oil Palm

In order to assess the effect of persistent drought stress on chlorophyll fluorescence parameters in leaves of oil palm, 2-year-old seedlings of oil palm were used as study materials, pot culture was adopted to simulate natural persistent drought. The chlorophyll fluorescence parameters and chlorophyll content were measured. And then the drought resistance was analyzed integrally with the method of subordination function. The results showed that under drought stress, the chlorophyll content, variable fluorescence (Fv), maximum fluorescence (Fm), variable fluorescence and maximum fluorescence ratio (Fv/Fm) of oil palm leaf decreased, but the initial fluorescence (F0) and non-photochemical quenching (NPQ) coefficient increased. This suggested that the photosystemⅡ (PS Ⅱ) was hurt by drought stress, which reduced the original light energy conversion efficiency (Fv/Fm) of PS Ⅱ, restrained photosynthetic electron transport and photosynthetic original reaction process, and increased the heat dissipation of protective effect. The changes of chlorophyll fluorescence parameters and chlorophyll content of the four varieties were different. The adaptability to drought from high to low was in an order as‘Reyou 6’,‘Reyou 8’,‘Reyou 2’and‘Reyou 4’. Therefore, the chlorophyll fluorescence parameters and chlorophyll content could be used as diagnostic index of drought resistance strength for oil palm drought-resistant breeding and related studies.