Influence of the Light Spectral Composition on Photosynthetic, Electro- and Morphophysiological Indicators of Small Radish in Conditions of Light Culture

• Published in: Russian journal of plant physiology 2024-04, Vol.71 (2), Article 59
• Main Authors: Kuleshova, T. E., Zhelnacheva, P. V., Ezerina, E. M., Vertebny, V. E., Khomyakov, Yu. V., Panova, G. G., Kochetov, A. A., Sinyavina, N. G.
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Composition; Cultivars; Dry matter; Growing season; Illumination; Indicators; Leaves; Life Sciences; Light; Light scattering; Light sources; Light transmission; Photochemicals; Photosynthesis; Photosynthetic apparatus; Photosynthetic pigments; Photosystem; Photosystem II; Plant Physiology; Plant Sciences; Radishes; Raphanus sativus; Research Papers; Solar radiation; Spectral composition
• ISSN: 1021-4437; 1608-3407
• DOI: 10.1134/S1021443724604622

The work examines the features of light sources influence simulating solar illumination with different spectral composition with a ratio of blue : green : red ranges of 11 : 35 : 54% (AFI-3000), 19 : 38 : 43% (AFI-4000), and 25 : 38 : 37% (AFI-5000) on morphometric, biochemical, photosynthetic, and electrogenic parameters of small radish ( Raphanus sativus L.) for photoculture of the ‘Peterburgskiy fioletovyy’cultivar. The conducted studies revealed a significant increase in the yield of roots (3.45 kg/m 2 for 28 days of growing season), dry matter content up to 8.9% and photosynthetic pigments, reduction in the amount of nitrates to 1206 mg/kg in radish plants illuminated with AFI-5000 spectrum lamps, close to solar radiation at noon. In this variant, an increase in the coefficients of the effective quantum photochemical yield of the PS II photosystem Y (II) = 0.206, photochemical qP = 0.304, and nonphotochemical qN = 0.415 of fluorescence quenching was observed as well as a high generation of potential difference up to 532 mV in the root environment compared to AFI-3000, simulating the light of the sun near the horizon, under which illumination a high proportion of light scattering by the leaf was observed (R800 = 1.716), and AFI-4000 with a spectrum close to morning light. The AFI-4000 option showed the worst result: increased unregulated excitation energy losses Y (NO) = 0.712 and light transmission by the leaf surface of 7.5%. The use of the AFI-5000 light source contributed to obtaining higher indicators characterizing both the yield of plant products and the activity of the photosynthetic apparatus and the intensity of electrogenic processes in the root environment, which makes it possible to recommend a lamp of this type for growing root crops under light culture conditions. This positive effect is likely due to the presence in the spectrum of a greater proportion of blue light, which affects the development of the root system.