高温对曼地亚红豆杉叶绿素荧光参数的影响

Effects of High Temperature on Taxus media Chlorophyll Fluorescence Parameters

以曼地亚红豆杉(Taxus mediacv.DGS)为材料,通过测定高温胁迫下曼地亚红豆杉叶绿素荧光参数的变化,探讨高温对曼地亚红豆杉光合作用的抑制机制。结果表明,高温胁迫下,Fv/Fo、Fv/Fm、Fv’/Fm’、qP以及ΦPSⅡ和ETR都有所下降,qN以及D和E都逐渐上升。高温抑制光合作用的原因之一是导致PSⅡ反应中心活性下降,光化学电子传递速率降低,另外,高温还影响了PSⅠ和PSⅡ的激发能分配平衡。

Taking Taxus media as the material, by monitoring the variation of chlorophyll fluorescence parameters of T. media on heat stress, this paper discussed the inhibition mechanism of the photosynthesis of T. media on heat stress. The results showed that Fv/Fo, Fv/Fm, Fv＇/Fm＇, qP, ФPSⅡ and ETR decreased with heat stress, qN, D and E increased gradually, the reason why photosynthesis was suppressed was high temperature, which might cause the decrease of the activity of PS Ⅱ reaction center, and the suppress of photochemical electron transfer rate. Distribution balance of excitation energy between PS Ⅰ and PS Ⅱ was influenced by high temperature as well.