Illumination intensity as a growth regulator for potato microplants in vitro

The aim of the study is the determination of the effect of increasing the photosynthetic photon flux density (PPFD) from 100 to 200 μmol/m²s on the in vitro growth, development and morphogenesis of single-node cuttings of potatoes of different cultivars. The following cultivars were involved into the investigation: ‘Krasa Meshchery’, ‘Sadon’ (Lorkh Federal Research Center of Potato), ‘Bylina Sibiri’, ‘Irtysh’ (Omsk Agricultural Scientific Center). The increase in PPFD was accompanied by a shortening of shoots by 12–32 %, depending on the cultivar, and a decrease in the number of internodes for all varieties by at least 10 %. A redistribution of biomass accumulation towards the root system was observed for all cultivars except the ‘Irtysh’ cultivar. The cultivars bred by the Lorkh Federal Research Center of Potato formed firm leaves. The ‘Irtysh’ cultivar showed a decrease in the content of chlorophylls and carotenoids, while the ‘Krasa Meshchery’ cultivar showed an increase. The area of the 4th leaf of these cultivars was maximum at 200 μmol/m²s. The stability of the electron transport chain of photosystem 2 to high PPFD increased, which is evident from the growth of chlorophyll A fluorescence parameters: maximum electron transport rate and minimum saturating light intensity, as well as the dynamics of rapid light curves of photochemical fluorescence quenching. Only the ‘Krasa Meshchery’ cultivar showed a decrease in F_v/F_m. Cultivar-specific reactions also included: a decrease in the proportion of plants with bushiness of the ‘Irtysh’ cultivar; an increase in the frequency of callus globule formation in the root zone and edema on leaves and shoots of Omsk-bred cultivars; and the formation of microtubers in the axil of the initiating cutting of the ‘Krasa Meshchery’ cultivar. Thus, increasing the PPFD to 200 μmol/m²s leads to the formation, for most of the studied cultivars, of plants that are more suitable for planting in soil or aeroponic/hydroponic conditions: low, with a well-developed root system, a larger leaf area and photosystems adapted to high light intensity. The exception is the cultivar ‘Krasa Meshchery’ due to the excessively short shoots (from 2 to 36 mm). For micropropagation, PPFD of 100 μmol/m²s is more suitable, with the exception of the cultivar ‘Irtysh’ due to the frequency of bushiness increasing under these conditions.

1. Wolf S., Kalman-Rotem N., Yakir D., Ziv M. Autotrophic and heterotrophic carbon assimilation of in vitro grown potato (Solanum tuberosum L.) plants. Journal of Plant Physiology. 1998;153(5-6):574–580. DOI: https://doi.org/10.1016/S0176-1617(98)80206-X

2. Seabrook J. Light effects on the growth and morphogenesis of potato (Solanum tuberosum) in vitro: A review. American Journal of Potato Research. 2005;82:353–367. DOI: https://doi.org/10.1007/BF02871966

3. Golovatskaya I. F., Dorofeev V. Yu., Medvedeva I. E., Nikiforov P. E., Karnachuk R. A. Optimization of illumination conditions in cultivation process of Solanum tuberosum L. cv. Lugovskoy microcuttings in vitro. Vestnik Tomskogo gosudarstvennogo universiteta. Biologiya = Tomsk State University Journal of Biology. 2013;(4):133–144. (In Russ.). URL: https://elibrary.ru/item.asp?id=21134451

4. 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: https://doi.org/10.1007/s10341-018-00414-0

5. Khalil M., Samy M., Aal A., Hamed A. The effect of light quality and intensity on in vitro potato cultures. Journal of Agricultural Sciences – Sri Lanka. 2023;18(3):364–374. DOI: https://doi.org/10.4038/jas.v18i3.9930

6. Martirosyan Yu. Ts., Dilovarova T. A., Martirosyan V. V., Kreslavskiy V. D., Kosobryukhov A. A. Photosynthetic apparatus of potato plants (Solanum tuberosum L.) grown in vitro as influenced by different spectral composition of led radiation. Sel'skokhozyaystvennaya biologiya = Agricultural Biology. 2016;51(5):680–687. (In Russ.). DOI: https://doi.org/10.15389/agrobiology.2019.1.130rus

7. Nakonechnaya O. V., Subbotin E. P., Grishchenko O. V., Gafitskaya I. V., Orlovskaya I. Yu., Kholin A. S. et al. In vitro potato plantlet development under different polychromatic LED spectra and dynamic illumination. Botanica Pacifica: a Journal of Plant Science and Conservation. 2021;10(1):69–74. DOI: https://doi.org/10.17581/bp.2021.10102

8. Grishchenko O., Subbotin E., Gafitskaya I., Vereshchagina Y., Burkovskaya E., Khrolenko Y. et al. Growth of Micropropagated Solanum tuberosum L. Plantlets under artificial solar spectrum and different mono- and polychromatic LED lights. Horticultural Plant Journal. 2022;8(2):205–214. DOI: https://doi.org/10.1016/j.hpj.2021.04.007

9. Stutte G. W., Yorio N. C., Wheeler R. M. Interacting effects of photoperiod and photosynthetic photon flux on net carbon assimilation and starch accumulation in potato leaves. Journal of the American Society for HortScience. 1996;121(2):264–268. DOI: https://doi.org/10.21273/JASHS.121.2.264

10. Subbotin E. P., Gafitskaya I. V., Nakonechnaya O. V., Zhuravlev Yu. N., Kul'chin Yu. N. The influence of artificial sunlight and its intensity on the growth and development of Solanum tuberosum regenerants. Turczaninowia. 2018;21(2):32–39. (In Russ.). DOI: https://doi.org/10.14258/turczaninowia.21.2.4

11. Kulchin Y. N., Nakonechnaya O. V., Gafitskaya I. V., Grishchenko O. V., Epifanova T. Y., Orlovskaya I. Y. et al. Plant Morphogenesis under Different Light Intensity. Defect and Diffusion Forum. 2018;386:201–206. DOI: https://doi.org/10.4028/www.scientific.net/ddf.386.201

12. Lisina T. N., Burdysheva O. V., Sholgin E. S. Effect of different LEDs light spectrum on potato (Solanum tuberosum L.) in vitro (review). Agrarnaya nauka Evro-Severo-Vostoka = Agricultural Science Euro-North-East. 2023;24(6):913–923. (In Russ.). DOI: https://doi.org/10.30766/2072-9081.2023.24.6.913-92

13. Varushkina A. М., Lugovskaya N. P., Maksimov A. Yu. The growth and productivity of potato (Solanum tuberosum L.) in photoculture. Vestnik Permskogo federal'nogo issledovatel'skogo tsentra = Perm Federal Research Centre Journal. 2019;(2):37–46. (In Russ.). DOI: https://doi.org/10.7242/2658-705X/2019.2.4

14. Lee Ni, Wetzstein H. Y., Sommer H. E. Effects of Quantum Flux Density on Photosynthesis and Chloroplast Ultrastructure in Tissue-Cultured Plantlets and Seedlings of Liquidambar styraciflua L. towards Improved Acclimatization and Field Survival. Plant Physiology. 1985;78(3):637–641. DOI: https://doi.org/10.1104/pp.78.3.637

15. Kadleček P., Tichá I., Haisel D., Čapková V., Schäfer C. Importance of in vitro pretreatment for ex vitro acclimatization and growth. Plant Science. 2001;161(4):695–701. DOI: https://doi.org/10.1016/S0168-9452(01)00456-3

16. Sáez P. L., Bravo L. A., Latsague M. I., Sánchez M. E., Ríos D. G. Increased light intensity during in vitro culture improves water loss control and photosynthetic performance of Castanea sativa grown in ventilated vessels. Scientia Horticulturae. 2012;138:7–16. DOI: https://doi.org/10.1016/j.scienta.2012.02.005

17. Kitaya Y., Fukuda O., Kozai T., Kirdmanee C. Effects of light intensity and lighting direction on the photoautotrophic growth and morphology of potato plantlets in vitro. Scientia Horticulturae. 1995;62(1–2):15–24. DOI: https://doi.org/10.1016/0304-4238(94)00760-D

18. Lichtenthaler H. K. Chlorophylls and carotenoids: Pigments of photosynthetic biomembranes. Methods in Enzymology. 1987;148:350–382. DOI: https://doi.org/10.1016/0076-6879(87)48036-1

19. Platt T., Gallegos C. L., Harrison W. G. Photoinhibition of photosynthesis in natural assemblages of marine phytoplankton. Journal of Marine Research. 1980;38:687–701.

20. Kacheyo O. C., Schneider H. M., de Vries M. E., Struik P. C. Shoot growth parameters of potato seedlings are determined by light and temperature conditions. Potato Research. 2024;67:1159–1186. DOI: https://doi.org/10.1007/s11540-023-09681-1

21. Naqvi B., Abbas H., Ali H. Evaluation of in vitro tuber induction ability of two potato genotypes. Pakistan Journal of Agricultural Sciences. 2019;56:77–81.

22. Wilson D. A., Weigel R. C., Wheeler R. M., Sager J. C. Light spectral quality effects on the growth of potato (Solanum tuberosum L.) nodal cuttings in vitro. In Vitro Cellular & Developmental Biology – Plant. 1993;29:5–8. DOI: https://doi.org/10.1007/BF02632231

23. Sita N. C., Iriawati, Kiriiwa Y., Suzuki K. Intumescence: A Serious Physiological Disorder in Plants. Reviews in Agricultural Science. 2024;12:182–212. DOI: https://doi.org/10.7831/ras.12.0_182

24. Zheng Y., Zou J., Lin S., Jin C., Shi M., Yang B. et al. Effects of different light intensity on the growth of tomato seedlings in a plant factory. PLoS ONE. 2023;18(11):e0294876. DOI: https://doi.org/10.1371/journal.pone.0294876