Effects of combined glycine and urea fertilizer application on the photosynthesis, sucrose metabolism, and fruit development of peach

The unreasonable use of urea and its low nitrogen use efficiency limit peach fruit yield and quality. In this study, six different fertilization treatments-no nitrogen fertilizer, urea (T1), glycine (T2), glycine:urea (1:1) (T3), glycine:urea (3:7) (T4), and glycine:urea (7:3) (T5)-were used to explore the effects of glycine and urea on the growth, photosynthesis, sucrose metabolism, and fruit development of peach. Peach had a higher utilization rate of glycine compared with urea; combined application of glycine-urea improved the utilization rate of urea compared with T1. T5 significantly increased the biomass of peach. High-dose glycine (T2 and T5) promoted the opening of stomata and the efficiency of photosynthetic electron transfer, which increased the net photosynthetic rate (P-n). In addition, the activity of Rubisco was higher in leaves on wild peach treated with T2 and T5, which increased the fixation of CO2. Under high-dose glycine treatment, the lower cell wall invertase activity in leaves and the higher cell wall invertase activity in fruits promoted the transfer of sucrose from source to sink. In addition, high-dose glycine treatment led to higher sucrose phosphate synthase activity in leaves and fruits, which improved the accumulation of soluble sugar in the fruit. The higher sucrose transport efficiency increased the single fruit weight, soluble solid content and ratio of sugar to acid in peach fruits under high-dose glycine treatment.

Automated summary

High-dose glycine treatment significantly improved peach tree biomass and fruit quality, enhanced photosynthetic efficiency, increased CO2 fixation, and raised soluble sugar content in fruits.