LEDs in Plant Tissue Culture: Boosting Micropropagation of Castanea sativa Cultivars

Plant diseases and environmental stresses significantly threaten global biodiversity and agroforestry ecosystems, making traditional management practices insufficient to meet the growing demand for sustainable, high-quality plant production. In this context, the micropropagation emerges as a promising technique for producing disease-free plants; however, its application in chestnuts remains challenging due to rooting recalcitrance and genotype dependency. Recent advances in light-emitting diode (LED) technology offer a potential solution to overcome these obstacles, as specific light wavelengths can be used to optimize the micropropagation process and improve overall efficiency. This study investigates the effects of LED treatments in the C. sativa (cv. ‘Marrone’) in vitro propagation, from multiplication to rooting and acclimatization phases. Four LED treatments were tested, and results were compared to fluorescent light (used as reference). Thirty days after the beginning of the experiment, morphometric and histological analyses were carried out. Two LEDs, Red:Blue:Far-red and Red:Blue:Green:Far-red, significantly improved the multiplication index (calculated as the number of new proliferated shoots from one explant), achieving rates (from 3.9 to 4.3 shoots/explant) that were twice as many as those observed under the reference lamp (2.0 shoots/explant). A rooting induction protocol was optimized and the application of LEDs resulted in 100% rooting success compared to 70% of the reference light. Similarly, LED treatments statistically affected leaf anatomical, morphological, and physiological traits, improving survival rates during the acclimatization phase. This represents a useful protocol for improving C. sativa in vitro propagation; it can be easily adopted and applied by nurseries for large-scale production.