Preliminary Study On Response Of Leaf Net Photosynthate And Other Photosynthetic Parameters To Fruit Transpiration In Peach Trees

The effects of smearing fruit with wax were investigated on net photosynthate (Pn) and other Photosynthetic parameters during the endocarp hardening stage and final stage of rapid fruit growth in five—years—old 'Yanfeng No.1' peach trees [Prunus persica (L.) Batsch.]. Fruit transpiration rate were decreased 57.9% and 41.4% respectively by smearing fruit with liquid wax of 1:10 and 1:100 wax/water solution. Decreased Pn, stomatal conductance (Gs) and transpiration rate (E) and increased leaf temperature (Tl) were observed on the treatment of fruits immersed in liquid wax. The substomatal CO₂ of source leaves was not significantly influenced by the decreased fruit transpiration. A significant positive linear correlation was found between Pn and Gs only when Gs was inferior to 0.2 mol ? m^-2 ? s^-1, and there was a parabolic correlation between Pn and Tl. Moreover Pn from the treatments of fruits immersed in liquid wax was lower, however, than that of CK in the same Tl. It is suggested that the decreased stomatal aperture and increased Tl may be an important mechanism in regulating photosynthate under a decreased strength of sink demand by reducing fruit transpiration rate in peach trees. The content of soluble solid, sugar and acid in the fruit, and the content of sugar and the activity of acid in leaf were not influenced by the decreased fruit transpiration.