冬季喷施多效唑对荔枝叶片叶绿素荧光特征的影响

为弄清多效唑(PP333)对荔枝叶片光合能力的影响,于2011年12月对‘妃子笑,荔枝整株喷施PP333(500 mg/L),研究其对叶片叶绿素指数和叶绿素荧光动力学参数的影响.结果表明:喷施PP333可显著增加荔枝叶片的SPAD值,且使Fv/Fm、Fv/F0、Fv′/Fm′、ΦPSⅡ、ETR、PCR等叶绿素荧光参数有所增加,而NPQ则降低；从光响应曲线可以看出,Fv′/Fm′、ΦPSⅡ和qP随光化光强度的增加呈下降趋势,而NPQ、PCR和ETR随光化光强度增加而增加；从PSⅡ反应中心能量分配比率上看,PP333处理后P、E增加,D减小,更有利于能量进入PSⅡ反应中心,促进光化学效率提高；PP333处理可以增加PSⅡ反应中心的开放比例,推动光合电子传递,提高荔枝叶片的光合性能.

The Chlorophyll Fluorescence Characteristics Change of Litchi Leaves after Sprayed PP333 in Winter

500 mg/L Paclobutrazol(PP333)solutions were sprayed to over-all canopy of litchi in December 2011 to study the influence of the chlorophyll index and the chlorophyll fluorometer kinetics parameters after fifteen days.The results showed that the value of SPAD was distinctly enhanced,and Fv/Fm,Fv/F0,Fv’/Fm’,ΦPSⅡ,ETR,PCR were enhanced somewhat,but NPQ was decreased after sprayed PP333.The measurements of light response curves showed that Fv’/Fm’,ΦPSⅡ and qP were decreased with the actinic light intensity increasing,but NPQ,PCR and ETR were increased as the actinic light intensity increased.Analysis of the energy distribution ratio of PSⅡreaction center showed that PP333 treatment led to higher levels of E and P,and lower level of D,suggesting that PP333 enhanced energy harvested by antenna pigments into PSⅡreaction center,which part of the energy dissipated non-photochemically,which was important for maintaining higher level of photochemistry of PSⅡ.The conclusion was that spraying PP333 could add the open proportion of PSⅡ reaction center,promote photosynthetic electron transport,and improve the photosynthetic function of litchi leaves.