Abstract□This study was conducted with ginseng plants to investigate photosynthetic response to changes of light intensity and leaf temperature. CO2 uptake in diurnal course was highest in the first phase (8 : 00~8 : 30 Am.) on may 30, 1992. In
CO2
uptake related to stomatal conductance, these relationship was synchronized in diurnal course, but relationship between CO2 uptake and intercellular CO2 concentration in diurnal course was synchronized oppositely. Leaf temperature and light
intensity at
the highest CO2 uptake were in the range of 23~24℃ and 95umol,m-2,s-1, respectively. In response to an increasing light intensity under a constant leaf temperature (18℃), CO2 uptake was increased throughout the light intensity sequence up to
250μpmol,m-2,s-1, When CO2 uptake was measured with a series of leaf temperature under a constant light intensity (250 μmol,m-2,s-1), CO2 uptake was highest at 18℃as a 4.1 μmol,m-2,s-1, Similar changes were also observed in stomatal
conductance
and
intercellular CO2 concentration. Evidences from several approaches indicate that synchronization of CO2 uptake, stomatal conductance and intercellular CO2 concentration were closely inter-related and changes of leaf temperature influenced the
photo-response in photosynthetic processes.
|