Do the Rich Always Become Richer? Characterizing the Leaf Physiological Response of the High-Yielding Rice Cultivar

The development of crops which are well suited to growth under future environmental conditions such as higher at-mospheric CO2 concentrations ([CO2]) is essential to meet-ing the challenge of ensuring food security in the face of the growing human population and changing climate. A high-yielding indica rice variety (Oryza sativa L. cv. Takanari) has been recently identified as a potential candidate for such breeding, due to its high productivity in present [CO2]. To test if it could further increase its productivity under ele-vated [CO2] (eCO2), Takanari was grown in the paddy field under season-long free-air CO2 enrichment (FACE, approxi-mately 200 mmol mol1 above ambient [CO2]) and its leaf physiology was compared with the representative japonica variety ‘Koshihikari’. Takanari showed consistently higher midday photosynthesis and stomatal conductance tha