STUDIES ON PHOTOSYNTHESIS CHARACTERISTICS OF POLLINATION CONSTANT NON-ASTRINGENT PERSIMMON NATIVE TO CHINA AND JAPAN

The photosynthesis and the diurnal variation curves of 2 different pollination constant non-astringent persimmon cultivars were measured by portable photosynthesis system TPS-2. The results showed that the diurnal variation curves of Pn of Maekawa-jirou and Eshi 1 were asymmetric double-apex curves. The photosynthesis siesta was caused mostly by non-stomatal limitation. The diurnal variation curves of transpiration rate (Tr) presented single-apex curves. The diurnal variation curves of the intercellular CO₂ concentration (Ci) presented double-valley ones. The diurnal variation curves of the stomatal conductance (Gs) presented double-apex curves. The diurnal variation curves of the water use efficiency (WUE) presented single-valley curves. The diurnal variation curves of the stoma limit ratio (SLR) presented double-apex curves. The average Pn of ‘Maekawa-jirou’ and ‘Eshi 1’ were 11.68 and 9.87 μmol CO₂ m^-2 s^-1. The light saturation point (LSP) of ‘Maekawa-jirou’ and ‘Eshi 1’ were 938.00 and 1219.00 μmol m^-2 s^-1. The light compensation point (LCP) of ‘Maekawa-jirou’ and ‘Eshi 1’ were 32.70 and 42.30 μmol m^-2 s^-1.