Growth, photosynthetic and physiological responses of Torreya grandis seedlings to varied light environments
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Shading could improve plant growth in Torreya grandis seedling, and 75 % shade is likely the optimum light irradiance level for its growth.
Light is a critical factor that affects the survival and early growth of tree seedlings. Torreya grandis, an economically important subtropical plant, is a shade-preferring species; however, the optimum light intensity for the growth of this species was still unclear. To determine the optimum light intensity, we examined the growth, chlorophyll fluorescence, gas exchange, and chloroplast ultrastructure of T. grandis seedlings growing under four levels of shade (i.e., 0, 50, 75, and 90 %). The results showed that T. grandis attained the greatest Pn and biomass when cultivated with 75 % shade. Seedlings grown under 75 % shade exhibited a 155 % increase in the height increment, a 440 % increase in the diameter increment, a 42.2 % increase in biomass, and a 102 % increase in the photosynthetic rate compared with seedlings grown in full sun. Moreover, 75 % shaded plants had the lowest antioxidant enzyme activities, malondialdehyde content and ion leakage. Full sunlight and 50 % shade significantly reduced the growth of T. grandis which was associated with a decrease in the maximal photochemical efficiency, photosynthetic rate, chlorophyll content and biomass compared with those under 75 % shade. Compared with the 75 % shaded plants, seedlings grown under 90 % shade had a reduced photosynthetic rate, which was accompanied by increased malondialdehyde content, relative electrolyte conductivity and antioxidant enzymes activities, suggesting that seedlings under the 90 % shade had the lower energy utilizing capacity. Higher antioxidant enzyme activities might be an efficient adaptation to protection against oxidative stress under low light conditions. Therefore, our results indicate that 75 % shade is likely the optimum light irradiance level for T. grandis seedling growth.
KeywordsGrowth Chlorophyll fluorescence Photosynthesis Chloroplast ultrastructure Torreya grandis
Author contribution statement
Designing the work: J.S.W.; running the experiments: H.T., Y.-Y. Hu., W.-W. Yu., L.-L.S.; data analysis and statistics: H.T. and Y.-Y. Hu; article writing and revising: H.T., Y.-Y. Hu., W.-W. Yu., L.-L.S., J.-S.W.
This work was funded by the Fruit Innovation Team Project of Zhejiang Province (2009R50033-7), the Zhejiang Provincial Natural Science Foundation of China (LZ12C16001), the Major Project of National Spark Plan of China (2012GA700001), the Launching Funds for Zhejiang A&F University (2013FR063), and the open project funds for forestry discipline in Zhejiang province (KF201312).
Conflict of interest
The authors declare that they have no conflict of interest.
- Ai XZ, Guo YK, Ma XZ, Xing YX (2004) Photosynthetic characteristics and ultrastructure of chloroplast of cucumber under low light intensity in solar greenhouse. Scientia Agricultura Sinica 37(2):268–273 (in Chinese)Google Scholar
- Anderson JM, Osmond CB (1987) Shade-sun responses: compromises between acclimation and photoinhibition. In: Kyle DJ, Osmond CB, Arntzen CJ (eds) photoinhibition. Elsevier Science Publishers, Amsterdam, pp 1–38Google Scholar
- Cheng XJ, Li ZJ, Yu WW, Dai WS, Fu QG (2007) Distribution and ecological characteristics of Torreya grandis in China. J Zhejiang For Coll 24(4):383–388 (in Chinese)Google Scholar
- Critchley C (1998) Photoinhibition. In: Raghavendra AS (ed) Photosynthesis: A comprehensive Treatise. Cambridge University Press, Cambridge, pp 264–272Google Scholar
- He DT, Chu KJ, Ren JJ, Yao CF, Dai WS (2013) Chinese Torreya industry and its culture in Shengzhou. J Zhejiang Forest Sci Technol 33(5):113–115 (in Chinese)Google Scholar
- Larcher W (1995) Physiological plant ecology, 3rd edn. Springer, Berlin, pp 74–89:253–264Google Scholar
- Li ZJ, Cheng XJ, Dai WS, Jing BH, Wang AG (2004) History and status and development of Torreya grandis in Zhejiang Province. J Zhejiang Forest Coll 21(4):471–474 (in Chinese)Google Scholar
- Lu JH, Li YF, Wang X, Ren L, Feng YM, Zhao XL, Zhang CL (2013) Impact of shading on growth, development and physiological characteristics of Trollius chinensis Bunge. Scientia Agricultura Sinica 46(9):1772–1780 (in Chinese)Google Scholar
- Pearcy RW, Sims DA (1994) Photosynthetic acclimation to changing light environments: scaling from the leaf to the whole plant. In: Caldwell MM, Pearcy RW (eds) Exploitation of environmental heterogeneity by plants: ecophysiological processes above- and below-ground. Academic Press, San Diego, pp 145–174Google Scholar
- Perrin PM, Mitchell FJG (2013) Effects of shade on growth, biomass allocation and leaf morphology in European yew (Taxus baccata L.). Eur J Forest Res 132(2):211–218Google Scholar
- Ushimaru T, Maki Y, Sano S, Koshiba K, Asada K, Tsuji H (1997) Induction of enzymes involved in the ascorbate-dependent antioxidative system, namely, ascorbate peroxidase, monodehydroascorbate reductase and dehydroascorbate reductase, after exposure to air of rice (Oriza sativa) seedlings germinated under water. Plant Cell Physiol 38(5):541–549CrossRefGoogle Scholar
- Valladares F, Chico J, Aranda I, Balaguer L, Dizengremel P, Manrique E, Dreyer E (2002) The greater seedling high-light tolerance of Quercus robur over Fagus sylvatica is linked to a greater physiological plasticity. Trees 16:395–403Google Scholar
- Yu YF (1999) A milestone of wild plants protection in China-the list of wild plants protected by the nation (the first batch). Plant Mag 5:3–11Google Scholar