Submitted to: American Society for Horticultural Science
Publication Type: Abstract Only
Publication Acceptance Date: July 15, 1998
Publication Date: N/A
Technical Abstract: The effect of specific light quality (e.g., white, red, blue, yellow, or orange light) was evaluated on morphogenesis. Characteristic differences in leaf shape, rooting, axillary shooting, and fresh weights are obtained by each light spectrum. However, light quality treatments also can result in a reduction of available light intensity provided to the culture which can be detrimental. Long term treatments (i.e., eight weeks) with certain light can result in severe stunting in growth or even culture death. This situation can be corrected by increasing the light intensity for each light quality spectrum employed or reducing the time of exposure. As an alternative, this study was conducted to determine if coupling colored light filters with enhanced ultra-high CO2 levels (e.g., 10,000 uL liter**-1 CO2) could result in growth rates comparable to that occurring in white light. The growth responses of shoot cultures from several species (i.e., lettuce, thyme, citrus) obtained from various spectra under ambient air and ultra-high CO2 levels are presented. Ultra-high CO2 levels enhanced culture growth regardless of the light quality employed. In some cases, cultures that were given ultra-high CO2 levels with several light treatments exhibited growth rates that exceeded that obtained from white light. Based on these results, ultra-high CO2 levels provide a beneficial effect coupled with light spectra on plant tissue cultures.