Effect of LED lighting regimes applied during the in vitro to ex vitro transition on the post-acclimatization growth of garden strawberry

While micropropagation technology is widely used in modern agriculture to produce high-quality, pathogen-free plant propagation material, optimizing plant growth regulator concentrations for in vitro micropropagation and ensuring successful ex vitro acclimatization remain challenges for different genotypes of garden strawberry ( Fragaria × ananassa Duch.). To produce the required number of plantlets of the Faith cultivar via clonal micropropagation, an optimal growth medium composition was used: Murashige–Skoog formulation supplemented with 0.5–0.75 mg/L of the 6-BAP growth regulator. The multiplication rate reached up to 9.5 shoots per explant in the third passage, and up to 10.5 shoots per explant in the fourth passage. During ex vitro acclimatization, three LED lighting regimes with different spectral compositions (White, Full, and Red:Blue) at approximately 75 μmol photons·m[−2] ·s[−1] were evaluated against the control (white daylight at 40 μmol photons·m[−2] ·s[−1] ). Throughout the experiment, strawberry microplants were assessed for leaf number, total leaf area, chlorophyll content index (CCI), and the effective quantum yield of photosystem II photochemistry. Eighty days after the start of the experiment, the higher light intensity resulted in a 73–78 % increase in the total leaf area and a 46–60 % increase in the CCI compared to the control. The number of leaves per plant varied between 5 and 7 across all lighting regimes without significant differences due to new leaf emergence and the periodic senescence of older leaves. Throughout the experiment, the maximum effective quantum yield was exhibited by control plants. Furthermore, the broad-spectrum LED lighting (Full) resulted in the highest CCI values, with this plant group entering the flowering phase after the experiment concluded. These findings validate the application of higher light intensity during the ex vitro stage, specifically with a spectral composition that incorporates red and blue light wavelengths.

1. FAOSTAT: Crops and livestock products. URL: https://www.fao.org/faostat/ru/#data/QCL

2. Gupta S. In vitro propagation and conservation of Fragaria species: IntechOpen, 2022. DOI: 10.5772/intechopen.103095. https://www.intechopen.com/chapters/80656.

3. Rasiukevičiūtė N., Morkeliūnė A., Mažeikienė I., Birzleja D., Lanauskas J., Valiuškaitė A. The influence of biological measures on strawberry plant growth, yield, and fruit quality, Plants. 2026;15(6):929. DOI: 10.3390/plants15060929. https://www.mdpi.com/2223-7747/15/6/929

4. Neri J. C., Meléndez-Mori J. B., Tejada-Alvarado J. J., Vilca-Valqui N. C., Huaman-Huaman E., Oliva M., Goñas M. An optimized protocol for micropropagation and acclimatization of strawberry ( Fragaria × ananassa Duch.) variety ‘Aroma’, Agronomy. 2022;12(4):968. DOI: 10.3390/agronomy12040968. https://www.mdpi.com/2073-4395/12/4/968.

5. Ambros E., Karpova E., Kotsupiy O., Trofi mova E., Zakabluk G., Chernonosov A., Koval V., Novikova T. A mechanocomposite based on biogenic silica and green tea flavonoids modulates adaptability of strawberry microclones to in vitro and ex vitro conditions, J. Soil Sci. Plant Nutr. 2023;23:612-627. DOI: 10.1007/s42729-022-01069-3. https://link.springer.com/article/10.1007/s42729-022-01069-3#citeas

6. Chaouch R., Kthiri Z., Soufi S., Jabeur M. B., Bettaieb T. Assessing the biostimulant effect of micro-algae and thyme essential oil during in vitro and ex vitro rooting of strawberry, South African Journal of Botany. 2023;162:120-128. DOI: 10.1016/j.sajb.2023.08.066. https://www.sciencedirect.com/science/article/pii/S0254629923005239?__cf_chl_tk=ssOT7zBeUu2YU2HzfM0dx8QMi7OSyJ9.9RHZ_63Nr8Q-1782125610-1.0.1.1mDjHxbIJMOABAXo.fMeoWcDSlva2OuGFQ6uA3a5VAyA

7. Kapitova I. A. The effect of plant growth regulators on the development of strawberry and wild microplants at the stage of adaptation to non-sterile conditions and during their further growing, Agrarian Bulletin of the Urals. 2026;26(1):118-128. DOI: 10.32417/1997-4868-2026-26-01-118-128. (in Russ.).

8. Karpushina M. V., Vinter M. A. Microclonal propagation of garden strawberry, Nauchnye trudy Severo-Kavkazskogo federal’nogo nauchnogo ce ntra sadovodstva, vinogradarstva, vinodeliya. 2021;31:108-113. DOI: 10.30679/2587-9847-2021-31-108113. (in Russ.)

9. Voytsekhovskaya O. V. Phytochromes and other (photo)receptors of information in plants, Fiziologiya rastenij. 2019;66(3):163-177. DOI: 10.1134/S0015330319030151. (in Russ.).

10. Kochetova G. V., Avercheva O. V., Bassarskaya E. M., Zhigalova T. V. Light quality as a driver of photosynthetic apparatus development, Biophysical Reviews. 2022;14:779-803. DOI: 10.1007/s12551-022-00985-z. https://link.springer.com/article/10.1007/s12551-022-00985-z

11. Paradiso R., Proietti S. Light-quality manipulation to control plant growth and photomorphogenesis in greenhouse horticulture: the state of the art and the opportunities of modern LED systems, Journal of Plant Growth Regulation. 2022;41:742-780. DOI: 10.1007/s00344-021-10337-y. https://link.springer.com/article/10.1007/s00344-021-10337-y

12. Bhattacharjee R., Kayang H., Kharshiing E. V. Engineering plant photoreceptors towards enhancing plant productivity, Plant Molecular Biology. 2025;115:64. DOI: 10.1007/s11103025-01591-9. https://link.springer.com/article/10.1007/s11103025-01591-9

13. Zakurin A. O., Shchennikova A. V., Kamionskaya A. M. Artificial-light culture in protected ground plant growing: photosynthesis, photomorphogenesis, and prospects of led application, Fiziologiya rastenij. 2020;67(3):246-258. DOI: 10.31857/ S0015330320030227. (in Russ.).

14. Demir K., Sarıkamış G., Seyrek G. Ç. Effect of LED lights on the growth, nutritional quality and glucosinolate content of broccoli, cabbage and radish microgreens, Food Chemistry. 2023;401:134088. DOI: 10.1016/j.foodchem.2022.134088. https://www.sciencedirect.com/science/article/pii/S0308814622020507#s0065

15. Su P., Ding S., Wang D. et al. Plant morphology, secondary metabolites and chlorophyll fluorescence of Artemisia argyi under different LED environments, Photosynth Res. 2024;159:153164. DOI: 10.1007/s11120-023-01026-w. https://link.springer.com/article/10.1007/s11120-023-01026-w#Abs1

16. Интернет-ресурс: Описание сорта Фейт https://active.inspection.gc.ca/francais/plaveg/pbrpov/cropreport/str/app00012524f.shtml

17. Matushkina O. V., Pronina I. N. Technology of clonal micropropagation of apple and pear: Guidelines. Michurinsk-Naukograd RF, 2008, 32 p. (in Russ.).

18. Kukharchik N. V. et al. Reproduction of fruit plants in culture in vitro. Minsk: Belarusian Science, 2016, 208 p. (in Russ.).

19. Murashige T., Skoog F. A revised medium for rapid growth and bio-assays with tobacco tissue cultures, Physiol Plant. 1962;15(3):473-497.

20. Matushkina O. V., Pronina I. N. Technological aspects for in vitro propagation of strawberry, Selekciya i sortorazvedenie sadovyh kul’tur. 2019;6(1):74-77.

21. Yang X.-L., An T., Ye Z.-W.-Y., Kang H.-J., Robakowski P., Ye Z.-P., Wang F.-B., Zhou S.-X. Modeling light response of effective quantum efficiency of photosystem II for C3 and C4 crops, Front. Plant Sci. 2025;16:1478346. DOI: 10.3389/fpls.2025.1478346. https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2025.1478346/full

22. Weis E., Berry J. A. Quantum effi ciency of photosystem II in relation to ‘energy’-dependent quenching of chlorophyll fluorescence, Biochimica et Biophysica Acta (BBA)-Bioenergetics. 1987;894(2):198-208. DOI: 10.1016/0005-2728(87)90190-3. https://www.sciencedirect.com/science/article/abs/pii/0005272887901903

23. Liu J., Van Iersel M. W. Photosynthetic physiology of blue, green, and red light: Light intensity effects and underlying mechanisms, Frontiers in plant science. 2021;12:619987. DOI: 10.3389/fpls.2021.619987. https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.619987/full

24. Vinskiene J., Bendokas V., Stanys V., Sasnauskas A., Rugienius R. The eff ect of osmotic stress, lighting spectrum and temperature on growth and gene expression related to anthocyanin biosynthetic pathway in wild strawberry ( Fragaria vesca L.) in vitro , Folia Horticulturae. 2023;35(2):419-431. DOI: 10.2478/ fhort-2023-0030. https://reference-global.com/download/article/10.2478/fhort-2023-0030.pdf

25. Kepenek K. Photosynthetic effects of light-emitting diode (LED) on in vitro-derived strawberry ( Fragaria x ananassa cv. Festival) plants under in vitro conditions, Erwerbs-Obstbau. 2019;61:179-187. DOI: 10.1007/s10341-018-00414-0.

26. Choi H. G. Correlation among phenotypic parameters related to the growth and photosynthesis of strawberry ( Fragaria × ananassa Duch.) grown under various light intensity conditions, Front. Plant Sci. 2021;12:647585. DOI: 10.3389/fpls.2021.647585. https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.647585/full