Abstract
To investigate the effect of the light spectrum on photosynthesis, growth, and secondary metabolites
Rosa hybrida ‘Scarlet’, Chrysanthemum morifolium ‘Coral Charm’, and Campanula portenschlagiana ‘BluOne’
were grown at 24/18 ◦C day/night temperature under purpose-built LED arrays yielding approximately
200 mol m−2 s−1 at plant height for 16 h per day. The four light treatments were (1) 40% Blue/60% Red,
(2) 20% Blue/80% Red, (3) 100% Red, and (4) 100% White (Control). The plant height was smallest in 40%
Blue/60% Red in roses and chrysanthemums, while the biomass was smallest in the white control in roses
and in 100% Red in chrysanthemums. The total biomass was unaffected by the spectrum in campanulas,
while the leaf area was smallest in the 40% Blue/60% Red treatment. In 100% Red curled leaves and
other morphological abnormalities were observed. Increasing the blue to red ratio increased the stomatal
conductance though net photosynthesis was unaffected, indicating excess stomatal conductance in some
treatments. With higher blue light ratio all phenolic acids and flavonoids increased. In view of the roles
of these secondary metabolites as antioxidants, anti-pathogens, and light protectants, we hypothesize
that blue light may predispose plants to better cope with stress.
Rosa hybrida ‘Scarlet’, Chrysanthemum morifolium ‘Coral Charm’, and Campanula portenschlagiana ‘BluOne’
were grown at 24/18 ◦C day/night temperature under purpose-built LED arrays yielding approximately
200 mol m−2 s−1 at plant height for 16 h per day. The four light treatments were (1) 40% Blue/60% Red,
(2) 20% Blue/80% Red, (3) 100% Red, and (4) 100% White (Control). The plant height was smallest in 40%
Blue/60% Red in roses and chrysanthemums, while the biomass was smallest in the white control in roses
and in 100% Red in chrysanthemums. The total biomass was unaffected by the spectrum in campanulas,
while the leaf area was smallest in the 40% Blue/60% Red treatment. In 100% Red curled leaves and
other morphological abnormalities were observed. Increasing the blue to red ratio increased the stomatal
conductance though net photosynthesis was unaffected, indicating excess stomatal conductance in some
treatments. With higher blue light ratio all phenolic acids and flavonoids increased. In view of the roles
of these secondary metabolites as antioxidants, anti-pathogens, and light protectants, we hypothesize
that blue light may predispose plants to better cope with stress.
| Original language | English |
|---|---|
| Journal | Journal of Plant Physiology |
| Volume | 171 |
| Issue number | 16 |
| Pages (from-to) | 1491-1499 |
| Number of pages | 9 |
| ISSN | 0176-1617 |
| DOIs | |
| Publication status | Published - 2014 |