The effects of light on plants depend on the energy dose and spectral characteristics. In this master thesis, we conducted seven experiments to investigate how supplemental UV-A light of two different wavelengths (365 and 385 nm) and its combination at different intensities affects the growth and selected physiological and biochemical properties of green leaf basil (Ocimum basilicum L.). We also compared the effect of UV-A light on two different varieties of basil, as well as the effect of the intensity of basal red-blue lighting on growth and physiological functions. Most of the measurements were made with advanced, high-throughput phenotyping equipment, but we also made some measurements in the conventional way with a fluorometer. We did not detect any major negative effects of UV-A on plant growth and photosynthetic functions, even at high doses of short-wavelength UV-A. Moreover, some processes were even enhanced under UV-A, as evidenced by a higher electron transfer rate (ETR) and increased photochemical efficiency. The anthocyanin index (ARI) also increased, while we did not detect any impact on the other vegetation indices. The results did not confirm the hypothesis that shorter wavelengths and higher UV-A intensities have a more negative effect on plants. When comparing the effect of UV-A on two different varieties, we did not find large differences. When considering the two different intensities of basal light, we found that that the intensity of basal light had a stronger effect on plants than the supplemental UV-A.
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