温室不同黄瓜幼苗叶绿素荧光参数和叶绿素相对含量的变化

Changes of Fluorescence Chlorophyll Parameters and Relative Level of Chlorophyll in Different Cucumber Seedlings in Greenhouse

研究了温室内2个黄瓜品种白天不同时刻叶绿素荧光参数和叶绿素相对含量的变化。研究结果表明,2个品种的初始荧光(Fo)和PSⅡ最大光化学量子效率(Fv/Fm)变化趋势基本一致,均是先逐渐下降,后又逐渐升高,但津优3号的Fv/Fm小于津春2号的;津优3号的PSⅡ电子传递量子效率(ΦPSⅡ)和光化学淬灭系数(qP)变化均较平缓,津春2号的ΦPSⅡ、qP则在11:30显著降低,出现了光抑制现象,其他时刻与津优3号基本一致;2个品种的叶绿素相对含量(SPAD值)变化趋势相当一致,先逐渐降低,到12:30达到最低,后又迅速升高,到13:30又恢复到9:30的水平,以后SPAD值基本保持不变。

The changes of fluorescence chlorophyll parameters and the relative level of the chlorophyll of two cucumber cultivars were investigated in different times of the daytime in greenhouse. The results showed that the changes of the initial fluorescence yield （Fo） and the maximal photochemical efficiency of PS II （Fv/Fm） of the two cultivars were basically unanimous, which were gradually declined first, and then gradually increased, but the Fv/Fm of Jinyou No.3 was lower than that of Jinchun No.2. The electron transfer quantum efficiency （ФPS II ） and the photochemical quenching coefficient （qP） of Jinyou No.3 were changed mildly from morning to afternoon, but those of Jinchun No.2 reduced significantly at 11：30 a.m., causing the photo inhibition phenomenon, and in the other times ФPS II and qP of Jinchun No.2 were similar with those of Jinyou No.3. The chlorophyll relative content （SPAD value） of the two cuhivars changed nearly the same, which was gradually decreased firstly, reaching the minimum value at 12：30, and later rapidly increased, and the SPAD value at 1：30 p.m. was the same with that at 9：30 a.m., and then the SPAD value remained basically unchanged.