Fig. 7.

Changes in rates of photosynthesis after excision of leaves of Takanari (filled circles) and Koshihikari (open circles) that had been grown in 3.0 l pots as determined at the tillering (A) and the heading (B) stages. Each leaf was excised at the base of the leaf blade after leaf gas exchange had reached a steady state. An ambient CO₂ concentration and the leaf–air vapour pressure difference were kept at 370 μmol mol⁻¹ and ∼1.5 kPa, respectively, before leaf excision, but they were not controlled after excision. Measurements at heading were taken when a panicle of a main stem emerged completely. Inserted tables show the rates of leaf photosynthesis of Takanari (Tak) and Koshihikari (Kosh) before and after excision (mean ±SD, n=3). An asterisk * indicates a significant difference at the 5% level between two varieties. ns: no significant difference.