银杏不同部位叶片叶绿素荧光参数动态变化规律研究

目的]探讨银杏不同部位叶片叶绿素荧光参数动态变化规律。方法]以华北地区人工栽培的银杏为试材,研究了其不同部位叶片叶绿素荧光参数的日、季节动态变化规律。结果]银杏叶片叶绿素荧光参数Fo、Fm、Fv、Fv/Fm、Fm/Fo、Fv/Fo的日变化呈现明显的先减小后增大的动态规律,一般在中午12：00达到最低值,向阳叶片的NPQ在中午时分达到最大值。银杏阴生叶的荧光参数Fm、Fv、Fv/Fm、Fm/Fo、Fv/Fo明显高于阳生叶,但NPQ最高峰出现时刻早于阳生叶,且峰值高于阳生叶,表明银杏阴生叶可能具有更为灵敏的热耗散机制。（3）与阳生叶相比,在不同测定时期阴生叶具有更高的PSⅡ潜在活性和内禀光能转换效率。结论]为保扩银杏资源提供了理论依据。

Dynamic Change Laws of Chlorophyll Fluorescence Parameters in Different Parts of Leaves of Ginkgo biloba

Objective] The aim was to explore the dynamic change laws of chlorophyll fluorescence parameters in different parts of leaves of Ginkgo biloba.Method] The G.biloba cultivated in North China was used as materials in this study to explore the law of daily change and ten-day change of the chlorophyll fluorescence parameters of leaves in different parts of leaves.Result] The daily change of Fm(maximal fluorescence),Fv(variable fluorescence),Fv/Fm,Fm/Fo(electron transfer rate),Fv/Fo(potential activity of PSⅡ)in leaves of G.biloba obviously presented a descending-ascending trend,the lowest value was at 12:00 and the NPQ(non-photochemical quenching)of sunny leaves arrived at the maximum at noon.The values of Fm,Fv,Fv/Fm,Fm/Fo,Fv/Fo in shade leaves of G.biloba were obviously higher than those in sunny leaves,but the peak value of NPQ of shade leaves presented earlier and higher,suggesting that the shade leaves might have more sensitive hot dissipation mechanism.Comparing to sunny leaves,shade leaves had the higher PSⅡ potential activity and inner light energy translation efficiency.Conclusion] This study had provided theoretical basis for the protection of G.biloba resources.