Effects of Red light on the Growth of Zantedeschia Plantlets in vitro and Tuber Formation Using Light-emitting Diodes

Abstract

Effects of light generated by red and blue light-emitting diodes on the photomixotrophic growth of Zantedeschia jucunda `Black Magic' plantlets in vitro and tuber formation after transplant under the same PPF and photoperiod were investigated. All five treatments had the same photosynthetic photon flux (PPF, 80 ± 5 μmol·m-2·s-1) and photoperiod (16 hours daytime/8 hours nighttime), leading to the same daily light integral. Results showed that the tubular fluorescent lamp (TFL) treatment had the highest value on chlorophyll content and dry weight accumulation than other treatments using light-emitting diodes (LEDs). In LED treatments, there were no significant differences on dry weight and growth rate but with significant differences on chlorophyll content and plant height when blue light LEDs were added. It revealed that blue light was involved in plant height and chlorophyll development control mechanism. Results also showed that minor difference in 28 days of transplant production (in vitro) among treatments does not extends after 6 months of tuber formation stage grown in greenhouse. At present, blue LEDs cost much more than that of red LEDs, results of this study suggested that using red LEDs alone and powered with AC is feasible for the commercial production of Zantedeschia plantlets in vitro.