ISHS Acta Horticulturae 440: International Symposium on Plant Production in Closed Ecosystems
EFFECT OF BLUE AND RED LIGHT INTENSITY ON PHOTOSYNTHETIC RATE OF STRAWBERRY LEAVES |
| Authors: | T. Yanagi, K. Okamoto, S. Takita |
| Keywords: | Fragaria x ananassa Duch., LED, light emitting diode, light quality, photosynthesis, PPF, transpiration |
| Abstract:
A few experiments have been done concerning the effects of light quality and photosynthetic photon flux (PPF) on plant leaf photosynthesis. This study was conducted to clarify the effects of the blue and red PPF level on plant leaf net photosynthesis below light saturation point. In this experiment, the net photosynthetic rate and the transpiration rate of mature strawberry (Fragaria x ananassa Duch. var. Ny oho) leaves were determined under eight different combinations of blue and red PPF at leaf surface level, by the Portable Photosynthesis and Transpiration System (LI-COR, LI-6400). Under each combination with a constant red PPF level (160 μmol m-2s-1) and blue PPF level at 60, 40, 17, and 0 μmol m-2s-1, the average net photosynthetic rates of five plants were 7.47, 7.18, 6.94, and 6.53 μmol m-2s-1, respectively. On the other hand, under each combination of a constant blue PPF level (60 μmol m-2s-1) and red PPF level at 130, 80, 30, and 0, the average net photosynthetic rates of five plants were 7.27, 5.75, 3.58, and 2.12 μmol m-2s-1, respectively. The photosynthetic efficiency PPF (Net photosynthetic rate/PPF) of blue and red PPF was calculated from the above mentioned results. The average photosynthetic efficiency of the red PPF was 0.0395 μmol CO2/ μmol photon, approximately 2.5 times higher than that of blue light. From these results, the relationship between plant leaf photosynthesis and blue and red PPF was discussed. | |
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