Volume: 5, 2026
5th International PhD Students’ Conference at the University of Life Sciences in Lublin, Poland:
ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: P001
DOI: https://doi.org/10.24326/ICDSUPL5.P001
Published online: 22 April 2026
LED light spectra and foliar silicon application enhance salinity tolerance in Medicago sativa by improving photosynthesis, ion homeostasis, and antioxidant defense
Ansar Abbas
State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China
Corresponding author: ansar2024@lzu.edu.cn
Salinity is a major abiotic stress limiting plant growth and productivity worldwide, particularly in controlled cultivation systems. Both light spectral composition and silicon supplementation are known to influence plant stress tolerance; however, their interactive effects in forage crops remain poorly understood. This study evaluated the combined effects of LED light spectra and foliar silicon application on physiological and biochemical responses of Medicago sativa under salinity stress. Plants were grown under controlled environmental conditions (25–27 °C, 70% relative humidity, 400 μmol m-2 s-1 PPFD, 16/8 h photoperiod) and exposed to two light spectra: red (R) and red + blue (R+B). Salinity stress was imposed using 100 and 200 mM NaCl with or without foliar application of 4 mM silicon. Growth parameters, gas exchange characteristics, chlorophyll fluorescence, ion accumulation, oxidative stress markers, and antioxidant enzyme activities were assessed after 14 days of treatment.
Salinity significantly reduced photosynthetic performance and plant growth while increasing Na⁺ accumulation and oxidative damage. Foliar silicon mitigated these effects by enhancing photosynthetic efficiency, maintaining a higher K⁺/Na⁺ ratio, and stimulating antioxidant enzyme activities, including superoxide dismutase, peroxidase, and catalase. Plants grown under red + blue light exhibited superior physiological performance compared with those under monochromatic red light. These findings demonstrate that optimizing LED light spectra combined with foliar silicon application can effectively enhance salinity tolerance and productivity of alfalfa in controlled environment agriculture.
Keywords: antioxidant defense; LED light spectrum; Medicago sativa; salinity stress; silicon; photosynthesis
How to cite
Abbas A., 2026. LED light spectra and foliar silicon application enhance salinity tolerance in Medicago sativa by improving photosynthesis, ion homeostasis, and antioxidant defense. In: 5th International PhD Students’ Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL5.P001