Effects of Light Quality on Growth，Photosynthetic Characteristics and Nitrogen Metabolism of Pepper Seedlings
LUO Xin-hui，LIU Ming-yue，LIU Yu-bing，HUANG Ke，WANG Jun-wei*
（College of Horticulture，Hunan Agricultural University，Engineering Research Center for Horticultural Crop Germplasm
Creation and New Variety Breeding, Ministry of Education，Key Labortory for Vegetable Biology of Hunan Province，Changsha
410128，Hunan，China）
Abstract：Light is a necessary condition for plant growth and development．To explore the effect of
light quality on pepper seedlings growth and development，this paper took ‘Xingshu 215’ as test material，
and conducted 4 different light quality treatments as given red+blue light（RB = 3∶1），red+blue+purple light
（RBP = 3∶1∶1），red+blue+green light（RBG = 3∶1∶1） and red+blue+near-infrared light（RBF =
3∶1∶1），and took white light treatment as the contrast（CK）．Then，the paper measured and analyzed the
effects of different light quality on shapes，leaf chlorophyll content，photosynthetic characteristics，chlorophyll
fluorescence and nitrogen metabolism of pepper seedlings．The results showed that the plant height，dry and
flesh weights above ground of pepper seedlings grown under treatment of RBP were the highest．At the same
time，the underground dry and flesh weights were significantly higher than those of the contrast and the other
treatments．All RB，RBG and RBP treatments had improved by different degrees the net photosynthetic rate
of pepper seedling．Among them，RB treatment had the largest increase amplitude than those of the contrast．
NPQ under treatment of RB was significantly higher than those of the contrast and the other treatments．The
value of ABS/RC，TRo/RC and ETo/RC of pepper seedlings under treatment of RBP were significantly higher
than those of the contrast and the other treatments．The treatment of RBF significantly improved the activities
of NR，GDH and GOGAT．In conclusion，The treatment of RBP enhanced dry matter accumulation of
pepper seedlings growth through significantly improving the ability to absorb and capture photons，optimizing
the distribution of light energy and improving the ability of electron transport．Combining the comprehensive
performance of morphological index with chlorophyll fluorescence，increasing purple light on the basis of
red+blue light was most beneficial to the growth of pepper seedlings．
