Effects of elevated CO2 on the capacity for photosynthesis of a single leaf and a whole plant, and on growth in a radish

Abstract

The atmospheric concentration of CO2 will probably rise to about 700 μmol mol-1 by the end of this century. The effects of elevated growth CO2 on photosynthesis are still not fully understood. Effects of elevated growth CO2 on the capacity for photosynthesis of a single leaf and a whole plant were investigated with the radish cultivar White Cherish. The plants were grown under ambient (∼400 μmol mol -1) or elevated CO2 (∼750 μmol mol-1). The rates of net photosynthesis per leaf area with a whole plant and a single leaf of plants of various ages (15-26 d after planting) were measured under ambient and elevated CO2. The rates of photosynthesis were increased by 20 28% by elevated CO2. There was no effect of elevated growth CO2 on the rate of photosynthesis, clearly indicating no downward acclimation of photosynthesis to elevated CO2. Elevated CO 2 increased dry weight accumulation by >27%. The effect of elevated CO2 on other growth characteristics will also be shown. JSPP © 2006.