Iron biofortification of broccoli microgreens under different radiation spectrum and composition of nutrient solution

In this study, broccoli microgreens ‘Green’ were grown indoors (T 21/17°C; RH 55%) for ten days under red 660 nm and blue 447 nm light-emitting diodes (LEDs) at 9:1 and 1:3 ratios (PPFD 200 µmol m^‑2 s^‑1) and in nutrient solution containing 2, 5, and 15 ppm of Fe.
The highest content of Fe was found in broccoli treated with 1:3×15 ppm.
Interestingly, broccoli treated with 9:1×15 ppm, and 1:3×5 ppm accumulated the same amount of Fe.
Also, the highest translocation factor was calculated from leaves and roots of broccoli treated with 1:3×15 ppm.
The bioaccumulation factor decreased with increasing concentration of Fe in nutrient solution regardless of the radiation spectrum.
Broccoli microgreens formed significantly larger leaves under 9:1×2 ppm, and longer hypocotyls under 9:1×15 ppm.
The chlorophyll, flavonol, and nitrogen balance, and plant senescence reflectance indexes were the highest of plants under 1:3×15 ppm, 9:1×2 ppm, 9:1×15 ppm, 1:3×5 ppm, respectively.
To sum up, the light can be used as a tool to increase the content of Fe in broccoli microgreens, but the uptake depends on the compositions of radiation spectrum and nutrient solution.

IX International Symposium on Light in Horticulture

V. Vaštakaitė-Kairienė, A. Brazaitytė, J. Miliauskienė, K. Laužikė, R. Sutulienė, P. Duchovskis, G. Samuolienė

bioaccumulation, leaf reflectance index, light-emitting diode, micronutrient, translocation factor

https://doi.org/10.17660/ActaHortic.2022.1337.25