Energy Efficiency of LEDs during Micropropagation of Helleborus ‘Molly’s White’

For many years, there has been a growing trend toward producing plants using tissue culture, the most efficient method at present. Every year, more and more protocols for micropropagation of economically valuable species are appearing. Many factors influence the regenerating explants under sterile laboratory conditions. One of the most important is light. The aim of the present study was to increase the efficiency of micropropagation of hellebore ‘Molly’s White’ using energy-efficient light-emitting diodes (LEDs), which were compared to traditionally used fluorescent lamps (FLs). To choose the best light and reduce production costs, white, blue or red LEDs with two levels of photosynthetic photon flux density (PPFD), 40 and 70 μmol/m 2 /s, were used at the multiplication and rooting stages. LED light color has been shown to affect regeneration rate and plant growth in length during micropropagation, while both light parameters (color as well as intensity) affect the length of regenerating shoots and the content of assimilation pigments in plants. The use of white LED light, which gives the highest multiplication rate, at an intensity of 70 μmol/m 2 /s saves more than 57 kWh during an 8-week micropropagation cycle compared to conventional fluorescent lamps with the same parameters.