Document Type : Research Paper


1 M.Sc. Graduate of Horticulture, Department of Horticulture, Faculty of Agriculture, Shahrekord University, Sahrekord, Iran

2 Assistant Professor, Department of Horticulture, Faculty of Agriculture, Shahrekord University, Sahrekord, Iran


According to the researches, plants behave differently under different light levels. Recent studies have demonstrated that proper light adjustment is critical for bedding plants transplant production. Transplant production under proper light and environmental conditions can increase their quality compared to traditional greenhouse production conditions.
Materials and Methods
In order to compare the effects of different LED light intensities in a growth chamber (a combination of white+ blue+ red LEDs equally in 60±5 and 120±5 µmol.m-2.s-1 levels) with sunlight during winter and spring cultivation at 9.6±5 and 14±5 µmol.m-2.d-1 DLI, respectively, a completely randomized design was established with 10 replications. Morphological and physiological traits of Pelargonium (Pelargonium hortorum 'Maverik Star'), Solenostemon (Solenostemon escutellariodes 'Wizard Scarlet') and Petunia (Petunia × hybrida 'Scarlet eye') transplants were evaluated during the treatment period. Transplants were evaluated in terms of morphological traits such as shoot fresh and dry weight, root fresh and dry weight, leaf area and plant height and root height. To determine dry weight, shoots and roots were dried in a drying oven at 72°C for 24 hours. Chlorophyll efficiency (Fv/Fm), anthocyanin and carotenoid contents also were measured during the experiment.
Results and Discussion
Eight weeks after seeding, leaf area, root length, shoot and root fresh and dry weight, leaf number, leaf surface temperature, carotenoid and chlorophyll contents, and photosynthetic efficiency were measured in transplants. Solenostemon and Geranium transplants were also evaluated for height, internode length, stem diameter and leaf anthocyanin content. Results showed that leaf area, leaf number, internode length, stem diameter, photosynthetic efficiency, shoot and root fresh and dry weight in Geranium and Solenostemon and chlorophyll content and leaf number in Petunia at 60±5 µmol.m-2.s-1 were significantly higher than the other treatments. The leaf surface temperature of transplants in both spring and winter cultivation treatments was higher than that of LEDs. The results showed that there was a significant difference between LED treated plants and sun light treatments. The LED treatments resulted in more compararison with the sun light treatment.
Transplants grown under identical proportion of white, blue and red LEDs manifested better morphological and physiological characteristics which led to better morphological features. According to the results, use of alternative or complementary light for the production of high-quality seedlings is beneficial. It is especially recommended in winter cultivation for production of proper transplants of Geranium, Solenostemon and Petunia.


Main Subjects

Abbasnezhad, R., Jabbarzadeh, Z., & Razavi, M. (2017). The effect of different levels of light intensity on some physical and Physical properties of Matthiola. Journal of Plant Research (Iranian Biology), 3(2), 1-12. [In Farsi]
Ardakani, M., Haj, S. H. M., & Notghi Taheri, H. (2004). Introduction to agricultural meteorology. (2nd ed). (pp: 50-59). Karaj: Islamic Azad University of Karaj Branch. [In Farsi]
Barta, D. J., Tibbits, T. W., Bula, R. J., & Morrow, R. C. (1992). Evaluation of light emitting diode characteristics for a space-based plant irradiation source. Advances in Space Research, 12, 141-149.
Bethke, C. L., & Carlson, W. H. (1985). Seed geraniums-18 year of research. Grower Talks, 49(6), 64-66.
Cerdan, P. D., & Chory, J. (2003). Regulation of flowering time by light quality. Nature, 423, 881-885.
Chehrazi, M., Pourghasemi, D., & Khoshbakht, M. (2018). The effect of planting methods and calcium nanoparticles spray on quality, quantity and vase life of Gladiolus hybrida cv. Magma. Plant Productions,41(2), 55-67. [In Farsi]
Dana, E., & Guiamet, M. J. (2004). Distortion of the SPAD 502 chlorophyll meter readings by changes in irradiance and leaf water status. Agronomy Journal, 24(2), 41-46.
Darko, E., Heydarizadeh, P., Schoefs, B., & Sabzalian, M. R. (2014). Photosynthesis under artificial light: the shift in primary and secondary metabolism. Philosophical Transactions of the Royal Society B: Biological Sciences, 369(1640), 30-43.
Devlin, M. R., & Withman, F. H. (2002). Plant physiology. New Delhi, India: CBs publishers and distributers.
Dole, J. M., & Wilkins, H. F. (2005). Floriculture: Principles and species. North American Colleges and Teachers of Agriculture, 4(4),70-75.
Edward, R. E., Carroll, L., & Shry, J. (1991). Introductory horticulture (4th ed). (pp: 13-16).  England: Delmar Publisher.
Faust, J. E., Holcombe, V., Rajapakse, N. C., & Layne, D. R. (2005). The effect of daily light integral on bedding plant growth and flowering. Horticultural Science, 40(3), 645-649.
Ghafari, H., & Tadayon, M. R. (2019). Impact of jasmonic acid on radiation use efficiency and dry biomasses of sugar beet (Beta vulgaris L.) under water deficit conditions. Plant Productions, 41(4), 11-124. [In Farsi]
Ghasemei Ghehsare, M., & Kafi, M. (2015). Scientific and practical floriculture (2nd ed). (pp: 40-42.). Tehran: Publishers Moalef. [In Farsi]
Hatamiyan, M., Arab, M., & Rozban, M. R. (2014). The effect of different light intensities on photosynthetic and non-photosynthetic pigments of two rose cultivars. Journal of Behzeraei Agriculture, 16(2), 281-289. [In Farsi
Inez, D., & Montagu, M. V. (2000). Oxidative stress in plants. ScienceDirect, 6(2), 153-158.
Jalili Marandi, R. (2010). Physiology of environmental stresses and mechanisms of resistance in horticultural plants. (2nd ed). (pp: 20-30). Urmia: Jahad Publications Urmia. [In Farsi]
Johkan, M., Shoji, K., Goto, F., Hashida, S., & Yoshihara, T. (2010). Blue light-emitting diode light irradiation of seedlings improves seedling quality and growth after transplanting in red leaf lettuce. Horticultural Science, 45(12), 1809-1814.
Kafi, M., Sharifi, H., Zand, A., & Damghani, M. (2012). Plant physiology (Vol. 1, 4th ed). Mashhad: Mashhad Academic Publications. [In Farsi]  
Khattak, A. M., & Pearson, S. (2006). Spectral filters and temperature effects on the growth and development of chrysanthemums under low light integral. Plant Growth Regulators, 49(1), 61-68.
Kim, S. J., Hahn, E. J., Heo, J. W., & Paek, K. Y. (2004). Effects of LEDs on net photosynthetic rate, growth and leaf stomata of chrysanthemum plantlets in vitro. Science Horticulture, 101(1-2), 143-151.
Kochaki, A., & Nasiri Mahalati, M. (1992). Ecology of crop plants. Mashhad: University of Mashhad Publications. [In Farsi]
Li, H., Xu, Z., & Tang, C. (2010). Effect of light-emitting diodes on growth and morphogenesis of upland cotton (Gossypium hirsutum L.) plantlets in vitro. Plant Cell, Tissue and Organ Culture, 103(2), 155-163.
Lichtenthaler, H. K., & Wellburn, A. R. (1983). Determinations of total carotenoids and chlorophylls a and b of leaf extracts in different Solvents. Biochemical Society Transactions, 11, 591-592.
Olschowski, S., Geiger, E. M., Herrmann, J. V., Sander, G., & Gruneberg, H. (2016). Effects of red, blue, and white LED irradiation on root and shoot development of Calibrachoa cuttings in comparison to high pressure sodium lamps. Acta Horticulturae, 1134(10), 245-250.
Ouzounis, T., Razi Parjikolaei, B., Frette, X., Rosenqvist, E., & Ottosen, C. O. (2015). Predawn and high intensity application of supplemental blue light decreases the quantum yield of PSII and enhances the amount of phenolic acids, flavonoids, and pigments in Lactuca sativa. Front Plant Science, 6, 1-19.
Rahnemoonfar, M., Etemadi, N., Nikbakht, A., Gheisari, M., & Sabzalian, M. R. (2014). Effect of shade, organic matter and planting time on morphological and physiological characteristics of lisianthus (Eustoma grandiflorum) (Raf.) Shinn. Plant Productions, 37(3), 1-11. [In Farsi]
Rezanezhad, F., & Tarahi, R. (2013). The effect of light and plant growth regulators on callus formation and anthocyanin accumulation in calli obtained from different cultures in rose galica (Rosa gallica L.). Journal of Plant Research. Iranian Journal of Biology, 26(2), 184-195. [In Farsi]
Rhie, Y. H., Lee, S. Y., Jung, H. H., & Kim, K. S. (2014). Light intensity influences photosynthesis and crop characteristics of (Jeffersonia dubia). Horticultural Science and Biotechnology, 32(5), 584-589.
Runkle, E. (2016). LED lighting applications for plants. Retrieved from http/
Runkle, E. (2017). Effects of blue light on plants.  Retrieved from http/
Sams, C. E., Kopsell, D., & Morrow, R. C. (2016). Light quality impacts on growth, flowering, mineral uptake and petal pigmentation of marigold. Acta Horticulturae, 56(1), 50-59.
Tennessen, D. J., Singsaas, E. L., & Sharkey, T. D. (1994). Light-emitting diodes as a light source for photosynthesis research. Photosynthesis Research, 39(1), 85-92
Verkbert, H., Heins, R., & Blom, T. (2004). Supplemental lighting on potted plants. In: P.R. Fisher and E. Runkle (Eds.), Lighting up profits: Un-derstanding greenhouse lighting (2nd ed). (pp: 10-13.). Willoughby, OH: Meister Media Worldwide.
Wagner G. J. (1979). Content and vacuole/extravacuole distribution of neutral sugars, free amino acids, and anthocyanin in protoplasts. Plant Physiology, 64(1), 88-93.
Weigue, F., Pingping, L., & Yanyou, W. (2012). Effects of different light intensities on chlorophyll fluorescence characteristics and yield in lettuce. Scientia Horticulturae, 135, 45-51.
Zhen, L., & Labeke, M. C. V. (2017). Long term effects of red and blue-light emitting diodes on leaf anatomy and photosynthetic efficiency of three ornamental pot plants. Frontiers in Plant Science, 8, 917.