Chinese Bulletin of Botany ›› 2016, Vol. 51 ›› Issue (1): 58-67.DOI: 10.11983/CBB14211

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Chemical Changes Caused by LED Lamps in Nutrient Solution and Its Effect on Plant Growth

Jia Li, Jinxing Chen, Zhizheng Li*   

  1. Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
  • Online:2016-01-01 Published:2016-02-01
  • Contact: Li Zhizheng
  • About author:? These authors contributed equally to this paper

Abstract:

Rice plants were grown in nutrient solution containing Si/FeEDTA and LED light. Plants grown distant from the light source could get effect carried by the circulation of nutrient solution. The solution containing Fe (100 mg∙L-1, FeEDTA) and Si (100 mg∙L-1, K2SiO3) was illuminated separately by sunlight and LED-purple in the solution. The OD400 of the solution increased with each illuminating day. The chemical change induced by illumination occurred between FeEDTA and K2SiO3. This chemical change was not related to solution temperature (°C) but was related to illumination only, so this was a photochemical reaction. The illuminated solution resulted in light absorbance from OD360 to OD560. An FeEDTA-SiO3 complex was isolated from the solution illuminated by LED blue or sunlight. This complex was again absorbed by a lining membrane to form a three-component complex. There was a large amount of complex (e.g., microcrystals) accumulated on the lining membrane. LED-purple, LED-red and LED-infrared could be induced to result in the FeEDTA-SiO3 complex. Chlorella beijerinch in the nutrient solution containing the FeEDTA-SiO3 complex grew well; dead algae broke down and left a brown-coloured fluffy ball of Fe-Si complex. The rice plants fed the FeEDTA- SiO3 complex showed high dry weight per plant.

Key words: LED, sunlight, photochemical reaction, FeEDTA-SiO3 complex, plant growth