Department of Plant Science, Seoul National University1
Research Institute for Agriculture and Life Sciences, Seoul National University2
Department of Horticulture, Biotechnology and Landscape Architecture, Seoul Women’s University3
This research was conducted to examine the effects of night interruption (NI) at different times on vegetative growth and flowering in Salvia splendens ‘Salsa’. Plants were grown in a growth chamber under 9-h photoperiod (short-day, SD) or 9-h photoperiod plus NI with light intensity at 3-5 μmol･m-2･s-1 photosynthetic photon flux. The NI was applied at 18:00-22:00 HR (NI18), 22:00-02:00 HR (NI22), or 02:00-06:00 HR (NI02). The net photosynthetic rate under NI18, NI22, and NI02 increased by 0.33, 0.16, and 0.13 µmol･CO2･m-2･s-1, respectively, during the NI period. Dry weight, plant height, and the number of nodes under NI were not significantly different from those of the plants under SD. However, flowering was earlier by approximately 9.8 days, and the number of flowers increased to 138.7 in NI02 compared to 36.4 flowers under SD at 17 weeks after the treatment. Our results indicate that NI02 was the most effective treatment in promoting flowering. Although vegetative growth of salvia was not increased in response to the increased net photosynthesis, flowering was promoted. Under NI18, NI22, and NI02 treatments, 77.8, 88.9, and 100.0% of salvia plants flowered within 8 weeks, whereas 44.4% of the plants flowered within the same time under SD conditions.
1. Blanchard, M.G. and E.S. Runkle. 2010. Intermittent light from a rotating high-pressure sodium lamp promotes flowering of long-day plants. HortScience 45:236-241.
2. Crawford, R.M.M. 1961. The photoperiodic reaction in relation to development in Salvia splendens. Ann. Bot. 25:78-84.
3. Kang, K.J., W. Oh, J.H. Shin, and K.S. Kim. 2008. Night interruption and cyclic lighting promote flowering of Cyclamen persicum under low temperature regime. Hort. Environ. Biotechnol. 49:72-77.
4. Kjaer, K.H. and C.O. Ottosen. 2011. Growth of chrysanthemum in response to supplemental light provided by irregular light breaks during the night. J. Amer. Soc. Hort. Sci. 136:3-9.
5. Kim, H.J., H.H. Jung, and K.S. Kim. 2011a. Influence of photoperiod on growth and flowering of dwarf purple loosestrife. Hort. Environ. Biotechnol. 52:1-5.
6. Kim, Y.J., H.J. Lee, and K.S. Kim. 2011b. Night interruption promotes vegetative growth and flowering of Cymbidium. Sci. Hortic. 130:887-893.
7. Kim, Y.J., H.J. Lee, and K.S. Kim. 2013a. Carbohydrate changes in Cymbidium ‘Red Fire’ in response to night interruption. Sci. Hortic. 162:82-89.
8. Kim, Y.J., S.Y. Lee, and K.S. Kim. 2013b. Photosynthetic characteristics of Cymbidium ‘Red Fire’ and ‘Yokihi’ at different developmental stages. Hort. Environ. Biotechnol. 54:9-13.
9. Mattson, N.S. and J.E. Erwin. 2005. The impact of photoperiod and irradiance on flowering of several herbaceous ornamentals. Sci. Hortic. 104:275-292.
10. Mizoguchi, T., L. Wright, S. Fujiwara, F. Cremer, K. Lee, H. Onouchi, A. Mouradov, S. Fowler, H. Kamada, J. Putterill, and G. Coupland. 2005. Distinct roles of GIGANTEA in promoting flowering and regulating circadian rhythms in Arabidopsis. Plant Cell 17: 2255-2270.
11. Niu, G., R.D. Heins, A.C. Cameron, and W.H. Carlson. 2001. Day and night temperatures, daily light integral, and CO enrichment affect growth and flower development of Campanula carpatica ‘Blue Clips’. Sci. Hortic. 87:93-105.
12. Oh, W., I.H. Cheon, K.S. Kim, and E.S. Runkle. 2009. Photosynthetic daily light integral influences flowering time and crop cha-racteristics of Cyclamen persicum. HortScience 44:341-344.
13. Park, D.H., D.E. Somers, Y.S. Kim, Y.H. Choy, H.K. Lim, M.S. Soh, H.J. Kim, S.A. Kay, and H.G. Nam. 1999. Control of circadian rhythms and photoperiodic flowering by the Arabidopsis GIGANTEA gene. Science 285:1579-1582.
14. Park, H.G., H.G. Ahn, S.T. Kim, and S.T. Choi. 2006. Effect of photoperiodic treatments on growth and flowering of Crocosmia crocosmiiflora. Flower Res. J. 14:252-257.
15. Park, Y.J., Y.J. Kim, and K.S. Kim. 2013. Vegetative growth and flowering of Dianthus, Zinnia, and Pelargonium as affected by night interruption at different timings. Hort. Environ. Biotechnol. 54:236-242.
16. Runkle, E.S., S.R. Padhye, W. Oh, and K. Getter. 2012. Replacing incandescent lamps with compact fluorescent lamps may delay flowering. Sci. Hortic. 143:56-61.
17. Taiz, L. and E. Zeiger. 2006. Plant physiology. 4th ed. Sinauer Associates, Sunderland, MA, USA.
18. Thomas, B. and D. Vince-Prue. 1997. Photoperiodism in plants. 2nd ed. Academic Press, London, UK.
19. Torres, A.T. and R.G. Lopez. 2011. Photoperiod and temperature influence flowering responses and morphology of Tecoma stans. HortScience 46:416-419.