The Characteristics of Photosynthesis and Dry Matter Production in Japonica Rice Cultivars with Different Type Panicles

【Objective】To clarify the material sources to form grain yield of different pamick types of rice cultivars the experiment was performed.【Method】Using 27 cultivars as materials, the photosynthetic characteristics and dry matter production and distribution of different types of rice were analyzed.【Result】The results indicated that the net photosynthesis in flag leaf and second leaf from above of erect and semi-erect panicle cultivars was higher than that of curved panicle cultivars at the full heading and ripening stages. The stomata conductance of erect and semi-erect panicle cultivars was bigger than that of curved panicle varieties at the full heading stage. But the difference of stomata conductance among three types of cultivars turned to be small. Compared with full heading stage, the intercellur CO2 concentration of the plants increased at the filling stage. In which the increase for curved panicle cultivars was significant. There was a significant positive correlation between the intercellur CO2 concentration at full heading and filling stages and grain yield.【Conclusion】The erect and semi-erect panicle cultivars could translate higher ratio of the matter to panicle and produce more grain yield because of their high photosynthesis efficiency and great transportation ability.