干旱和复水对草莓叶片叶绿素荧光特性的影响

Effects of drought stress and rehydration on chlorophyll fluorescence characteristics in Fragaria×ananassa Duch

采用日本丰香草莓(Fragaria×ananassa Duch.cv.Toyonoka)品种进行实验,研究干旱和复水对其叶片叶绿素荧光特性的影响。结果表明,随着干旱胁迫程度的加剧,草莓叶片的最大荧光(Fm)、PSⅡ原初光能转化效率(Fv/Fm)、PSⅡ实际光化学效率(Yield)、光化学猝灭系数(qP)都随干旱胁迫的加剧而下降。干旱胁迫14d后,不同处理组草莓叶片的叶绿素荧光参数存在着显著的差异(P<0.05)。复水后,低度胁迫和中度胁迫处理组能较快地恢复到正常水平,但重度胁迫组与对照组存在着显著的差异(P<0.05)。

Water deficiency is a limiting factor for plant growth and development because it can severely affect a wide range of physiological processes such as photosynthesis in plants. Chlorophyll fluorescence assays provide a rapid and noninvasive means to study the behavior of plant photosynthetic systems under drought stress. This study was conducted to characterize the drought stress induced changes in chlorophyll fluorescence parameters in strawberry,Fragaria ananassa Duch. cv. Toyonoka. Plants were treated with four different soil water levels,75% （CK）,55% （T1）,35% （T2）,and 15% （T3） （ratio of relative water content to maximum moisture capacity in field）. After 14 days of drought stress,plants were slowly rehydrated Chlorophyll fluorescence parameters were measured. The results showed that the maximal fluorescence （Fm）,light energy transformation efficiency of PSII （Fv/Fm）,actual photochemical efficiency of PSII during illumination （Yield）,photochemical quenching coefficient （qP） declined fluorescence parameters with decreasing soil water content. A significant difference in the chlorophyll was found among different treatments （P〈0.05）. Damages in the plants treated with low or moderate drought stress could rapidly recover after rehydration. However,damage recovery in the plants under the severe drought stress and control differed significantly （P〈0.05） after rehydration.