Department of Horticultural Science & Biotechnology, Seoul National University1
Research Institute of Agriculture and Life Sciences, Seoul National University2
Jeffersonia dubia is a spring-flowering perennial found in rich forests in Korea and Northern China and has potential as an ornamental or medicinal plant. However, illegal picking and land use change have decreased the number of populations and overall population size of this plant in its natural habitat. Although J. dubia has been reported to be a shade-preferring plant, no study has determined the optimum light intensity for its growth. The objectives of this work were to observe the effects of various shading levels on the physiological responses of J. dubia and to determine the proper shading level for cultivation. Treatments consisted of four shading levels (0%, 50%, 75%, and 95% shade) imposed using black mesh cloth. The number of leaves and dry weight increased with decreased shading. The shoot-to-root ratio increased with increased shading, mainly due to decreased root dry weight under shading. Plants showed low net CO2 assimilation rates and Fv/Fm values combined with low dry matter levels when grown under 0% shade (full sunlight). These results indicate that J. dubia plants experience excessive irradiance without shading, resulting in damage to the photosynthetic apparatus. By contrast, the net photosynthesis rate increased as the shading level increased. Fv/Fm, the potential efficiency of PSII, was 0.8 under 95% shade, indicating that J. dubia is well-adapted under heavy shading. However, the low dry matter of plants in the 95% shade treatment indicated that the low light intensity under 95% shade led to a decline in plant growth. Thus, moderate light (50% shading) is recommended for cultivating J. dubia without physiological defects.
1. Aro, E.M., I. Virgin, and B. Andersson. 1993. Photoinhibition of photosystem II. Inactivation, protein damage and turnover. Biochim. Biophys. Acta 1143:113-134.
2. Bae, K. 2000. The medicinal plants of Korea. Kyo-Hak Publishing Co., Seoul.
3. Barber, J. and B. Andersson. 1992. Too much of a good thing: Light can be bad for photosynthesis. Trends Biochem. Sci. 17:61-66.
4. Bertamini, M., K. Muthuchelian, M. Rubinigg, R. Zorer, R. Velasco, and N. Nedunchezhian. 2006. Low-night temperature increased the photoinhibition of photosynthesis in grapevine (Vitis vinifera L. cv. Riesling) leaves. Environ. Expt. Bot. 57:25-31.
5. Björkman, O. and B. Demmig-Adams. 1994. Regulation of photo-synthetic light energy capture, conversion and dissipation in leaves of higher plants, p. 17-47. In: E.-D. Schulze and M.M. Caldwell (eds.). Ecophysiology of photosynthesis. Springer, Berlin.
6. Bolhar-Nordenkampf, H., M. Hofer, and E. Lechner. 1991. Analysis of light-induced reduction of the photochemical capacity in field-grown plants. Evidence for photoinhibition? Photosyn. Res. 27:31-39.
7. Bolhar-Nordenkampf, H.R. and G. Öquist. 1993. Chlorophyll fluorescence as a tool in photosynthesis research, p. 193-206. In: D.O. Hall, I.M.O. Scurtock, H.R. Bolhar-Nordenkampf, R.C. Leegood, and S.P. Long (eds.). Photosynthesis and production in a changing environment: A field laboratory manual. Chapman & Hall, London.
8. Cornic, G. and J.M. Briantais. 1991. Partitioning of photosynthetic electron flow between CO and O reduction in a C3 leaf (Phaseolus vulgaris L.) at different CO concentrations and during drought stress. Planta 183:178-184.
9. Dai, Y., Z. Shen, Y. Liu, L. Wang, D. Hannaway, and H. Lu. 2009. Effects of shade treatments on the photosynthetic capacity, chlorophyll fluorescence, and chlorophyll content of Tetrastigma hemsleyanum Diels et Gilg. Environ. Expt. Bot. 65:177-182.
10. Demmig-Adams, B. 1990. Carotenoids and photoprotection in plants: A role for the xanthophyll zeaxanthin. Biochim. Biophys. Acta 1020:1-24.
11. Gamon, J.A. and R.W. Pearcy. 1990. Photoinhibition in Vitis californica: The role of temperature during high-light treatment. Plant Physiol. 92:487-494.
12. Genty, B., J.-M. Briantais, and N.R. Baker. 1989. The relationship between the quantum yield of photosynthetic electron transport and quenching of chlorophyll fluorescence. Biochim. Biophys. Acta 990:87-92.
13. Huang, M. 1995. New ornamental crops in Asia. Acta Hortic. 397:43-58.
14. Hutchinson, J. 1920. Jeffersonia and Plagiorhegma. Bul. Miscellaneous Info. 7:242-245.
15. Kong, W.J., J. Wei, P. Abidi, M.H. Lin, S. Inaba, C. Li, Y.L. Wang, Z.Z. Wang, S.Y. Si, H.N. Pan, S.K. Wang, J.D. Wu, Y. Wang, Z.R. Li, J.W. Liu, and J.D. Jiang. 2004. Berberine is a novel cholesterol-lowering drug working through a unique mechanism distinct from statins. Nature Medicine 10:1344-1351.
16. Krause, G.H. 1988. Photoinhibition of photosynthesis. An evaluation of damaging and protective mechanisms. Physiol. Plant. 74: 566-574.
17. Lee, S.Y., S.C. Lee, S.T. Park, J.C. Rhee, T.J. Lee, K.J. Kim, and J.S. Lee. 2008. Effect of shading level of nursing bed on the shoot growth of rooted cuttings in native Hydrangea serrata for. acuminata. Flower Res. J. 16:153-160.
18. Long, S.P., H. Humphries, and P.G. Falkowski. 1994. Photoinhibition of photosynthesis in nature. Ann. Rev. Plant Physiol. Plant Mol. Biol. 45:633-662.
19. Maxwell, C., H. Griffiths, A.M. Borland, M.S.J. Broadmeadow, and C.R. McDavid. 1992. Photoinhibitory responses of the epiphytic bromeliad Guzmania monostachia during the dry season in Trinidad maintain photochemical integrity under adverse conditions. Plant Cell Environ. 15:37-47.
20. Miralles, J., J.J. Martínez-Sánchez, J.A. Franco, and S. Bañón. 2011. Rhamnus alaternus growth under four simulated shade environments: Morphological, anatomical and physiological responses. Sci. Hort. 127:562-570.
21. National Institute of Environmental Research (NIER). 2004. The conservation strategy for the endangered and reserved plants based on the ecological and genetic characteristics (IV). National Institute of Environmental Research, Korea.
22. Ögren, E. and M. Sjöström. 1990. Estimation of the effect of photoinhibition on the carbon gain in leaves of a willow canopy. Planta 181:560-567.
23. Osmond, C. 1994. What is photoinhibition? Some insights from comparisons of shade and sun plants, p. 1-24. In: N.R. Baker and J.R. Bowyer (eds.). Photoinhibition of photosynthesis, from the molecular mechanisms to the field. BIOS Scientific Publ., Oxford.
24. Pastenes, C., E. Santa-Marıa, R. Infante, and N. Franck. 2003. Domestication of the Chilean guava (Ugni molinae Turcz.), a forest understorey shrub, must consider light intensity. Sci. Hortic. 98:71-84.
25. Reichenauer, T., H.R. Bolar-Nordenkampf, U. Ehrlich, G. Soja, W.F. Postl, and F. Halbwachs. 1997. The influence of ambient and elevated ozone concentrations on photosynthesis in Populus nigra. Plant Cell Environ. 20:1061-1069.
26. Sorrentino, G., L. Cerio, and A. Alvino. 1997. Effect of shading and air temperature on leaf photosynthesis, fluorescence and growth in lily plants. Sci. Hortic. 69:259-273.
27. Taiz, L. and E. Zeiger. 2007. Plant physiology. Sinauer Associates, Inc., Publishers, Sunderland, Massachusetts.
28. Yoo, Y.K. and K.S. Kim. 1997. Effects of shading on the growth in Hibiscus syriacus L. J. Kor. Soc. Hort. Sci. 38:520-526.
29. You, J.H., Y.H. Jin, H.W. Cho, and C.H. Lee. 2005. Effect of shading ratio on growth of Korean native ferns. Flower Res. J. 13:90-96.