Impact of LED light sources on morphogenesis and levels of photosynthetic pigments in Gerbera jamesonii grown in vitro

anglais. Gerbera jamesonii cv. Dura is a well-known and economically important ornamental crop that is produced using micro-propagation. This study aimed to evaluate the effect of various light wavelengths in six different light emitting diode (LED) treatments on biometric attributes and photosynthetic pigment content in gerbera plants grown in vitro. The LED treatments were B (100% blue), RB1 (50% red and 50% blue), RB2 (70% red and 30% blue), RBW (40% red, 40% blue, and 20% white), RBfR (49% red, 49% blue, and 2% far red), and R (100% red). Light quality was seen to significantly affect plant growth and development. The highest shoot multiplication rate was observed in plants grown under both RB1 and RB2. Plantlets grown under R displayed the greatest shoot elongation, and their petioles were three times longer than those grown under B. Both B and R resulted in reduced leaf blade area. Rooting of shoots was observed in plants grown under all light treat-ments; however, R stimulated adventitious root formation. The average number of roots produced by plants under all light treatments was calculated and found to match that produced under RB2. The RBfR treatment caused a reduction in leaf dry weight compared to that produced under B, which represented the highest leaf dry weight. Control fluorescent lighting, sup-plied by Philips TL-D 36W/54 lamps, had a positive effect on root dry weight. Photosynthetic pigment content was higher in the leaves of rooted plants compared to that in plants at the multiplication stage. RB2 resulted in high er concentrations of chlorophyll a and band carotenoids, whereas lower accumulation of photosynthetic pigments was observed under R. These results demonstrate that light wavelength manipulation through LEDs can be strategically used for the rapid and large-scale propagation of gerbera. The outcomes of this study offer potential to improve micropropagation efficiency and reduce the costs of in vitro plant production.

anglais. Carotenoids; Chlorophyll; Leaf phenotyping analysis; Light quality micropropagation; Leaf phenotyping analysis

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