Partitioning of 13C-labelled photosynthate varies with growth stage and panicle size in high-yielding rice.

A super-high-yielding rice (Oryza sativa L.) cultivar, Takanari, and a traditional japonica rice cultivar, Nakateshinsenbon, were grown under field conditions to compare partitioning of C-labelled photosynthate to different plant organs during the period of reproductive development. The flag leaf and the two leaves immediately below it on the main culm were exposed individually to CO and the movement of the heavy carbon isotope to grains, hull, panicle branches and vegetative parts of plant was assessed.