Abstract
The biomass production of rice grown under red light supplemented with blue light was higher than that grown red light alone, which was caused by an increase in photosynthetic rate associated with a higher leaf N content. However, it is unclear whether the increase in photosynthetic rate by increased stomatal conductance is related to the promotion of growth by supplemental blue light. We investigated the photosynthetic characteristics under short-term red, blue and mixture of red and blue light irradiation in rice and spinach.
The photosynthetic rate decreased and stomatal conductance did not change with increasing the ratio of blue light PFD in the measurement light PFD. Blue light did not promote photosynthesis more than red light. To analyze the mechanisms underlying an increase leaf N content by supplemental blue light, some measurements including nitrate reductase activity and nitrate content in xylem sap are being analyzed.
