African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6576

Full Length Research Paper

Effects of different red to far-red radiation ratios on the senescence of greenhouse chrysanthemum leaves

Z. Q. Yang1,2, Y. X. Li1,2*, X. D. Jiang1,2, J. Zhu2 and J. B. Zhang2
  1Jiangsu Key Laboratory of Agricultural Meteorology, Nanjing University of Information Science and Technology, Nanjing, 210044, China. 2College of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, 210044, China.
Email: [email protected]

  •  Accepted: 31 January 2012
  •  Published: 26 March 2012

Abstract

 

Red (660±30 nm) and far-red (730±30 nm) LED light sources were combined in different proportions to yield a design with four R:FR ratio treatments (0.5, 2.5, 4.5 and 6.5). Chrysanthemum plants irradiated with natural light served as the control (R:FR=1.02). The chlorophyll a (Chla) content and SPAD value of chrysanthemum leaves were highest for an R:FR ratio of 2.5 and lowest for an R:FR ratio of 6.5. The chlorophyll b (Chlb) and carotenoid content were highest for an R:FR ratio of 0.5 and lowest for R:FR ratios of 6.5 and 2.5, respectively. The superoxide dismutase (SOD), peroxidase (POD) activity and soluble protein content of the chrysanthemum leaves were highest for an R:FR ratio of 2.5, whereas the catalase (CAT) activity was highest for an R:FR ratio of 4.5. The SOD, POD, CAT activity and soluble protein content were found to be lowest for an R:FR ratio of 0.5. The malondialdehyde (MDA) content of the chrysanthemum leaves was highest for an R:FR ratio of 0.5 and lowest for an R:FR ratio of 2.5. These results implied that the antioxidant enzyme activity and the anti-senescence ability of the chrysanthemum leaves were highest for an R:FR ratio of 2.5 and lowest for an R:FR ratio of 0.5.

 

Key words: Chrysanthemum, R:FR, senescence, chlorophyll, antioxidant enzyme.