叶绿素荧光测定技术的研究

目的]规范叶绿素荧光测定程序。方法]以4个美国山核桃品种的实生苗为材料,在田间测定叶片基部、中部、尖部的F0、Fm、Fv/Fm和Fv/F0值,并在0、5、10、20、40、60min时间段中选择最佳的暗适应时间。结果]美国山核桃叶片不同部位的F0值几乎无差异,Fm、Fv/Fm、Fv/F0值有一定的差异,Fv/Fm、Fv/F0均表现为叶基部>叶中部>叶尖部,差异不显著。美国山核桃叶片除F0外,Fm、Fv/Fm、Fv/F0均在暗适应5min后测得最大值,与未暗适应的处理在品种间有显著或极显著差异,但品种Elliot暗适应10min的Fm比5min的稍大。田间测定并不是暗适应时间越长越好,测试品种表现一致。结论]美国山核桃苗期叶片不同部位Fv/Fm、Fv/F0表现为叶基部>叶中部>叶尖部。夏季田间测定荧光参数时,测定前叶片暗适应5min即可。

Studies on the Determination Technique of Chlorophyll Fluorescence

Objective The aim of the research was to standardize the determination process of chlorophyll fluorescence.Method With the seedling of 4 pecan varieties as materials,F0,Fm,Fv /Fm and Fv /F0 in leaf base,middle part and tip part were determined in the field and the optimum dark adaptation time was selected from different time of 0,5,10,20,40,60 min.Result The F0 values in different positions of pecan leaves had no difference and Fm,Fv /Fm,and Fv /F0 had certain differences.The order of Fv /Fm and Fv /F0 both showed as follows:base> middle part > tip part without significant differences.Except F0,Fm,Fv /Fm and Fv /F0 in pecan leaves all reached the maximum values after dark adaptation for 5 min.They had significant differences or extremely significant differences among the varieties without dark adaptation treatment,but Fm in leaves of variety Elliot after dark adaptation for 10 min was slightly greater than that for 5 min.It was not right that the longer the dark adaptation time was,the better the results were.Test varieties had accordant performances.Conclusion The order of Fv /Fm and Fv /F0 values in different positions of pecan leaves both showed as follows:base> middle part > tip part without significant differences.When fluorescence parameters were determined in summer,the dark adaptation for 5 min before determination was feasible.