花期干旱对不同基因型大豆叶绿素荧光特性的影响

Response of Chlorophyll Fluorescence to Drought Stress at Flowering in Different Soybeans

利用叶绿素荧光动力学测定技术,测定开花期干旱不同基因型大豆品种叶绿素荧光参数的变化。以3个不同基因型大豆品种为材料,应用OS52FL调制式叶绿素荧光仪研究在开花期干旱胁迫下,各荧光参数的变化及用方差分析进行综合评价。结果表明,大豆开花期受旱后,可变荧光与最大荧光比(Fv/Fm)、可变荧光与初始荧光比(Fv/F0)、非光化学淬灭系数(NPQ)均降低,而电子传递速率(ETR)升高,说明光系统Ⅱ(PSⅡ)受到了伤害,使得PSⅡ原初光能转换效率(Fv/Fm)、PSⅡ潜在活性(Fv/F0)、起光保护作用的热耗散降低,光合电子传递速率升高。且荧光参数之间具有相关性。花期干旱胁迫后,各参数存在基因型差异,新大豆1号在花期干旱条件下,光合机构受破坏较轻,其吸收的光能能较多的用于光化学转化能力,抗旱能力强。因此,花期干旱胁迫下,叶绿素荧光参数的变化与大豆品种抗旱性有关,利用大豆叶绿素荧光特性对干旱胁迫的反应差异鉴定品种抗旱性是可行的。

Known as the rapid non-destructive probe for studying plant photosynthesis, chlorophyll fluorescence analysis has been gradually put into use in studying the effects of stressful environments on plant photosynthesis. To investigate the effect of drought stress at flowering on chlorophyll fluorescence characters of soybean, three soybean genotypes were adopted, and the change of the chlorophyll fluorescence parameters were determined by using OS52FL chlorophyll fluorometer. Under the condition of drought at flowering, the ratio of the variable to maximum fluorescence（Fv/Fm） ;the ratio to of variable to minimal fluorescencet （Fv/Fo ） and non- photochemical quenching coefficient （NPQ） decreased, while the electron transport rate（ETR） increased. The analysis indicated that photosystem Ⅱ damaged ,and primary light energy conversion of PS Ⅱ （ Fv/ Fm） ,potential activities of PS Ⅱ （Fv/Fo ） and heat disseminate which possess photoprotective effect were decreased and photosynthetic electron transport increased, and the chlorophyll fluorescence parameters were closely correlated with each other. The change of chlorophyll fluorescence parameters under drought stress at flowering varied with genotypes, and the damage of photosynthetic apparatus of Xindadou 1 was lighter,so more light energy absorbed by Xindadou 1 was converted into chemical energy and the ability of drought tolerance was stronger. Therefore, it is possible to determine the drought resistance in soybean using chlorophyll fluorescence characters.