The influence of lighting on the seeds germination of chinese cabbage and broccoli and antioxidant activity of microgreens in the closed system of the synergotron ISR 1.01

Abstract

Relevance. Growing plants in artificial conditions (closed agroecosystems) requires precise regulation of plant growth factors, starting from the first stages of ontogenesis. One of the parameters is the presence or absence of light in the period of seed germination. For most types of cabbage the standard method is germination in the dark, but for freshly harvested seeds (at rest) light exposure is necessary. According to the literature, the mechanisms of the effect of light on seed germination are complex and ambiguous, so the issue needs detailed research.Methods. Therefore, the purpose of this work was to study the germination of seeds of broccoli (Brassica oleracea var. italica Plenck) and Chinese cabbage (Brassica rapa var. chinensis), taking into account the light factor and the simultaneous analysis of antioxidant activity as a marker of changes in metabolic processes.Results. The experiment has revealed a significant increase in the antioxidant activity of the microgreens during germination in the dark compared to germination in the light (in broccoli by 5.5 times, in Chinese cabbage by 4.8 times). Later on, after the seedlings are moved to the light, the differences between the light and dark versions practically disappear. After germination in the light, the antioxidant activity of microgreens in comparison with the original (dry seeds) decreased by 3-3.5 times, while in the dark – on the contrary, increased by 1.5-1.6 times. The final results of germination (germination energy and seed germination) practically do not differ in the versions. In the case of dark germination, the height of microgreens is greater (due to etiolation and stretching in the absence of light), however, later on, the differences in the versions are smoothed out. The biomass of microgreens in the version of light germination on the 4th day after sowing seeds in broccoli is by 9.1% higher, in Chinese cabbage – by 10.5%. In case of Chinese cabbage, differences remained until the end of the experiment (on the 18th day from sowing seeds), in case of broccoli they were smoothed out. Comparison of two kinds of cabbage has showen that broccoli in the closed system of the synergotron forms a much higher aboveground biomass than Chinese cabbage (on the 4th day after sowing – by 37%, on the 18th day – by 75.4% in the dark version).

Keywords

• seed germination
• microgreens
• broccoli
• chinese cabbage
• light exposure
• synergotron
• closed agroecosystems
• antioxidant activity