Abstract: The effects of foliar spraying different concentrations of mannitol on chlorophyll content of peach leaves and fruit quality were analyzed to screen the optimal spraying concentration and provide a reference for improving peach fruit quality in production. Three peach varieties, including Chunmi, Century Star and Pengxian 15, were used as experimental materials and treated with 0 (CK), 5 g/L (T1), 10 g/L (T2), 20 g/L (T3), and 40 g/L (T4) mannitol foliar spraying. Chlorophyll content of peach leaves and fruit quality-related indicators were measured, and a comprehensive evaluation of each physiological index was conducted. The results showed that the soluble solids, soluble sugar and fructose content of Chunmi under T1 treatment were significantly increased by 18.38%, 16.67% and 17.56%, respectively, compared with CK; the fructose content, glucose content, sucrose content, longitudinal diameter, transverse diameter and single fruit weight of Century Star under T4 treatment were significantly increased by 14.03%, 14.28%, 13.01%, 2.86%, 4.58% and 6.53%, respectively, compared with CK; the fructose, glucose and sucrose content of Pengxian 15 under T4 treatment were significantly increased by 66.47%, 62.09% and 17.81%, respectively, compared with CK. Comprehensive analysis showed that the optimal mannitol concentrations for improving fruit quality of Chunmi, Century Star and Pengxian 15 were 5, 40 and 40 g/L, respectively.

Key words: peach, fruit quality, mannitol