LED光质补光对黄瓜幼苗生长和光合特性的影响

采用发光二极管（light emitting diode，LED）精确调制光谱能量分布，以单色光质（红光、蓝光、UV-B）和组合光质（红/蓝1∶1）进行每天4 h补光，以未补光组为对照，研究LED光质补光对黄瓜幼苗生长和光合特性的影响。结果表明：与未补光组相比，LED光质补光处理显著促进了黄瓜幼苗的生长；不同光质对黄瓜幼苗生长和光合特性的影响具有一定的差异性。其中，UV-B处理显著提高了黄瓜幼苗叶片单位鲜质量的叶绿素a、叶绿素b和类胡萝卜素含量，但显著降低了Fv/Fm；红光处理显著提高了黄瓜幼苗的真叶数、叶面积、株高、干鲜质量、壮苗指数、根系活力、SOD活性和可溶性蛋白含量。总体而言，红光有利于培育壮苗，较适合作为黄瓜育苗的补光光质。

Effects of Supplemental Lighting with LED Light Quality on Growth and Photosynthetic Characteristics of Cucumber Seedlings

The effects of light spectral energy distribution of light emitting diode （LED） on growth and photosynthetic characteristics of cucumber（Cucumis sativus L.）seedlings were studied．The light emitting diodes with different light qualities（red light，blue light，UV-B light and red/blue 1∶1 light）were used as 4 h supplemental lighting，taking none supplemental lighting treatment as the contrast．The experimental results showed that compared with none supplemental lighting treatment，the different 4 h supplemental lighting quality treatments affected the growth and photosynthetic characteristics of cucumber seedlings significantly in different ways．UV-B treatment increased the contents of Chl a，Chl b and caroteniod in unit fresh mass，but reduced the value of Fv/Fm significantly．Red treatment increased the leaf number，leaf area，plant height，fresh and dry weight，the health index，root activity，SOD activity and soluble protein content significantly．Overall，red light is more beneficial for culturing cucumber seedlings，and is suitable to be used as supplementary light quality for cucumber seedling cultivation．