光照强度对菠菜光合色素的影响

Effects of Light Intensity on Photosynthetic Pigments of Spinach

本文以400、240、50μmol·m^(-2)·s^(-1)3种不同光照强度处理菠菜,测定菠菜叶片中叶绿素a、叶绿素b、β-胡萝卜素和叶黄素含量的动态变化。结果表明:菠菜叶绿素a、叶绿素b的含量随着光照强度的增强而逐渐升高,且在高光强(400μmol·m^(-2)·s^(-1))下,植株叶片中2种色素含量随处理时间的延长呈逐渐升高的趋势,对照(240μmol·m^(-2)·s^(-1))植株含量在处理期间无明显变化,低光强(50μmol·m^(-2)·s^(-1))下,2种色素含量呈降低的趋势,30 d时各处理间差异显著;β-胡萝卜素含量随着光照强度的降低呈升高的趋势,30 d时低光强处理植株含量显著高于对照和高光强处理植株;叶黄素含量:低光强>高光强>对照,20 d和30 d时,低光强处理植株含量显著高于高光强和时照植株。可以推论,高光强有利于菠菜叶绿素的合成,低光强有利于类胡萝卜素的形成。

In this study, the time-dependent changes of contents of chlorophyll a, chlorophyll b, β-carotene and lutein were measured under three light intensities（400, 240, 50 p^mol＇m^-2·s^-1）in spinach leaf. The results showed that the contents of chlorophyll a and chlorophyll b enhanced with the increasing of light intensity; and under high light intensity （400 μmol·mm^-2·s^-1）, they continuously increased throughout the experiment, and they had no changes in control （240 μmol·m ^-2· s^-1） plants, however, they gradually decreased in plants exposed to low light intensity（50 μmol·m^-2·s^-2）; differences among three treatments were significant in 30 d. β-carotene content increased with the decrease of light intensity, and it was much higher in plants under low light intensity than that under high light intensity and control in 30 d. The content of lutein： low light intensity 〉 high light intensity 〉 control; and it was much higher in plants under low light intensity than that under high light intensity and control in 20 d and 30 d. These results suggest that high light intensity may favor synthesis of chlorophyll, and low light intensity may help to carotenoid formation.