Microgreens Biometric and Fluorescence Response to Iron (Fe) Biofortification

Abstract

Microgreens are foods with high nutritional value, which can be further enhanced with biofortification. Crop biofortification involves increasing the accumulation of target nutrients in edible plant tissues through fertilization or other factors. The purpose of the present study was to evaluate the potential for biofortification of some vegetable microgreens through iron (Fe) enrichment. The effect of nutrient solution supplemented with iron chelate (1.5, 3.0 mg/L) on the plant's growth and mineral concentration of purple kohlrabi, radish, pea, and spinach microgreens was studied. Increasing the concentration of Fe in the medium increased the Fe content in the leaves of the species under study, except for radish. Significant interactions were observed between Fe and other microelements (Mn, Zn, and Cu) content in the shoots. With the increase in the intensity of supplementation with Fe, regardless of the species, the uptake of zinc and copper decreased. However, the species examined suggested that the response to Fe enrichment was species-specific. The application of Fe didn't influence plant height or fresh and dry weight. The chlorophyll content index (CCI) was different among species. With increasing fertilisation intensity, a reduction in CCI only in peas resulted. A higher dose of iron in the medium increased the fluorescence yield of spinach and pea microgreens. In conclusion, the tested species, especially spinach and pea, grown in soilless systems are good targets to produce high-quality Fe biofortified microgreens.

Keywords: artificial light; functional food; microelements; microscale vegetables.

Figure 1

The fresh mass (A, g plant⁻¹) and dry matter ratio (B, %) for four microgreen crops depend on the Fe level. Two levels of iron nutrition in the medium were used: 1.5 and 3.0 mg/L. Different letters for the same parameter indicate significant differences at the 5% level, according to Duncan’s test. The bars represent the standard deviation.

Figure 2

The length (cm) for four microgreen crops depends on the Fe level. Two levels of iron nutrition in the medium were used: 1.5 and 3.0 mg/L. Different letters for the same parameter indicate significant differences at the 5% level, according to Duncan’s test. The bars represent the standard deviation.

Figure 3

The CCI (A) and the fluorescence yield ((B), Fv/Fm) for four microgreen crops depend on the Fe level. Two levels of iron nutrition in the medium were used: 1.5 and 3.0 mg/L. Different letters for the same parameter indicate significant differences at the 5% level, according to Duncan’s test. The bars represent the standard deviation.

Figure 4

Hierarchical clustering demonstrates studied parameters of microgreens in relation to the level of Fe. Two levels of iron nutrition in the medium were used: 1.5 and 3.0 mg/L.

Figure 5

Principal components analysis (PCA) of microgreens showed a correlation between the level of Fe and measured parameters. Two levels of iron nutrition in the medium were used: 1.5 and 3.0 mg/L.