Efecto de la iluminación LED sobre la multiplicación <i>in vitro</i> de <i>Laelia anceps</i> Lindl.

It has been shown that environmental factors such as light quality and intensity, as well as the lighting regime (photoperiod or continuous light) affect the development of explants in micropropagation systems, due to the induction of physiological responses of different nature. The objective of this research was to evaluate the effect of LED light sources of different spectral composition and growth regulators 6-BAP and 2,4-D at different concentrations on the in vitro development of Laelia anceps Lindl. seedlings. In addition, seedlings obtained in vitro were evaluated in two culture media (semisolid and liquid). The variables evaluated were number of shoots, number of roots, number of leaves, dry matter, chlorophyll a, b, total and carotenoid content. Analyses of variance (ANOVA) were performed with the data and means were compared with the LSD test (p ≤ 0.05). The highest mean number of shoots (4.44 ± 0.44) and number of roots (3.11 ± 1.54) were obtained in the treatment containing 10 mg L-1 of 6-BAP and exposed to red + blue LED light, while the concentration of photosynthetic pigments was higher in the treatment with white and red light. The use of liquid culture medium (temporary immersion systems) showed no significant differences between the tested treatments when compared to the semisolid culture medium.