不同光强处理对设施桃树光合及荧光特性的影响

以二年生“春捷”毛桃为试材，研究了日光温室内遮荫处理桃树在不同光照强度条件下光合特性以及荧光特性的变化。结果表明：随着光照强度的降低，桃树叶片的光补偿点、光饱和点、CO2饱和点（CSP）、CO2补偿点（CCP）、Rubisco活性、表观光合量子效率（AQY）、光呼吸速率、乙醇酸氧化酶（GOX）活性和羧化效率（CE）均呈下降趋势；光合色素含量在不同光强条件下变化较大，两个弱光处理叶绿素a（Chl.a）、叶绿素b（Chl.b）、 类胡萝卜素(carotenoids)的含量均比对照升高。不同光强条件对桃树叶片的荧光参数φPSⅡ、Fo和Fv/Fm的日变化影响显著，弱光照处理的φPSⅡ、Fv/Fm的日变化比较平稳而且维持在一个较高的水平，而对照的上述两个参数的日变化波动较大；三个不同光强处理的Fo的日变化均是在10：00开始上升，在13：00达到最高点而后下降，变化趋势基本一致。

Effects of Different Photon Flux Density on the Characteristics of Photosynthesis and Chlorophyll Fluorescence of Peach Trees in Protected Culture

Two-year-old “chunjie” peach tree as materials , the changes of the characteristics of photosynthesis and chlorophyll fluorescence were investigated through shading in protected culture. The result showed: the light compensation point(LCP)、light saturation point(LSP)、CO2 saturation point(CSP)、CO2 compensation point(CCP)、Rubisco activity 、apparent quantum yield (AQY)、photoresperition、Glycolic acid oxidase activity and carboxylation efficiency(CE) reduced with the reduction of photo flux intensity; but the content of chlorophyll and carotenoid increased under low light environment. The diurnal changes of φPSⅡ、Fo and Fv/Fm were different apparently, and the diurnal changes of φPSⅡ and Fv/Fm of the two low light trentments were stable and had high values, but the full sunlight treatment changed sharply; the diurnal changes of Fo values of three treatments were similar.