Publication Date
1985
Location
Kyoto Japan
Description
Characteristics of photosynthesis and transpiration were examined with attached leaves of eight C3 and fourteen C4 grasses under different light conditions. On the basis of these data, water use efficiency, leaf conductance and intercellular CO2 concentration were also calculated. Light saturation point and maximum photosynthetic rate of C4 grasses were higher than those of½ grasses. The light response curve of transpiration was similar in both grasses. However, the values of C3 grasses were higher than those of C4 grasses at a broad range of light intensity. Water use efficiency of both grasses increased rapidly with increasing in light intensity till 30 klx and then it showed a constant value. The water use efficiency of C4 grasses was double that of C3 grasses at high light intensity. The light response curve of leaf conductance and intercellular CO2 concentration showed reciprocal patterns in both grasses. However, those values of C4 grasses were smaller than those of ½ grasses. The relationships of water use efficiency and intercellular CO2 concentration with leaf conductance in all grasses under high light intensity showed a high negative correlation for water use efficiency and a high positive correlation for intercellular CO2 concentration. From the results, it was considered that high water use efficiency in C4 grasses was dependent on higher photosynthesis rather than lower transpiration, and it is suggested that the CO2 supply to the inner leaf in C4 grasses was effective because of a large CO2 gradient between ambient and inner leaf under conditions of smaller leaf conductance.
Citation
Agata, W; Kawamitsu, Y; Hakoyama, S; and Kaufman, P B., "Characteristics of Photosynthesis, Transpiration and Water Use Efficiency of C3 and C4 Grass Leaves" (1985). IGC Proceedings (1985-2023). 6.
(URL: https://uknowledge.uky.edu/igc/1985/ses3/6)
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Characteristics of Photosynthesis, Transpiration and Water Use Efficiency of C3 and C4 Grass Leaves
Kyoto Japan
Characteristics of photosynthesis and transpiration were examined with attached leaves of eight C3 and fourteen C4 grasses under different light conditions. On the basis of these data, water use efficiency, leaf conductance and intercellular CO2 concentration were also calculated. Light saturation point and maximum photosynthetic rate of C4 grasses were higher than those of½ grasses. The light response curve of transpiration was similar in both grasses. However, the values of C3 grasses were higher than those of C4 grasses at a broad range of light intensity. Water use efficiency of both grasses increased rapidly with increasing in light intensity till 30 klx and then it showed a constant value. The water use efficiency of C4 grasses was double that of C3 grasses at high light intensity. The light response curve of leaf conductance and intercellular CO2 concentration showed reciprocal patterns in both grasses. However, those values of C4 grasses were smaller than those of ½ grasses. The relationships of water use efficiency and intercellular CO2 concentration with leaf conductance in all grasses under high light intensity showed a high negative correlation for water use efficiency and a high positive correlation for intercellular CO2 concentration. From the results, it was considered that high water use efficiency in C4 grasses was dependent on higher photosynthesis rather than lower transpiration, and it is suggested that the CO2 supply to the inner leaf in C4 grasses was effective because of a large CO2 gradient between ambient and inner leaf under conditions of smaller leaf conductance.
