EFFECTS OF EAR REMOVAL ON PHOTOSYNTHESIS OF THE FLAG LEAF DURING GRAIN FILLING IN WHEAT

In order to clarify the response of crops to sink restriction, we examined the effects of ear removal on photosynthesis of the flag leaf in wheat. For 11 days there was no difference in CO2 exchange rates between the control and the no-ear plants after ear removal, but after 11 days the rates in the no-ear plants were higher. For 11 days there was no difference in diffusive conductance, apparent quantum yield (AQY) and apparent carboxylation efficiency (ACE) and chlorophyll contents between the plants. Though there was no difference in diffusive conductance, AQY and chlorophyll contents between the plants after 11 days, ACE and ribulose- 1, 5 -bisphosphate carboxylase/oxygenase contents in the no-ear plants were higher than those in the control. Therefore, it was presumed that activity of CO2 fixation system in the no-ear plants was higher and that flag leaf senescence was delayed due to ear removal.