Light Spectrum Effects on Growth and Development of Potato Plantlets In Vitro

This study evaluated the impact of various light qualities on the in vitro micropropagation of two potato (Solanum tuberosum L.) varieties, Diamant and Cara, using light-emitting diodes (LEDs). Five light treatments were applied to node cuttings in a modified MS media under controlled conditions to examine plantlet growth under five LED spectral treatments: warm white (WW), white (W), red (R), blue (B), and a combination of 75% red and 25% blue (RB). Morphological, physiological, and biochemical parameters were assessed after four weeks, while microtuberization characteristics were evaluated after eight weeks. Results indicated that light quality significantly influenced plantlet growth; red light treatment produced the tallest plantlets, and the red-blue combination (RB) yielded the highest leaf area, root number, stem diameter, health index and Dickson Quality index (DQI). The RB treatment also achieved the highest microtuberization degree, percentage, number of microtubers, and total yield per vessel. Chlorophyll and carotenoid contents were highest under RB and blue light. The Diamant variety showed superior microtuberization degree and starch content, while Cara exhibited higher microtuber Number, weight and size. The findings demonstrate that the optimization of light quality, particularly using a combination of blue and red LEDs, enhances both vegetative growth and microtuber formation in potato micropropagation, which could improve the efficiency of in vitro pre-basic seed potato production.