Effects of bagging on fruit flavor quality and related gene expression of AsA synthesis in Actinidia eriantha

Three lines of Actinidia eriantha with high AsA content were used to determine die effects of bagging and control (never bagged) on fruit external and internal qualities, as well as transcript levels for key genes involved in ascorbic acid (AsA) synthesis. Compared with the control, there was no significant difference between bagging and control in soluble solid, dry matter, soluble sugar and titrable acid, but bagging would significantly improve fruit appearance and flesh color, reduced the content of chlorophyll, carotenoid and AsA. The key gene expression involved in AsA synthesis showed that the expressions of GME, GMP, GGP, GPP and GaIDH in bagging were inconsistent with the control on three lines. Whereas GaILDH, GalUR and DHAR had the same expression trend and significantly lower than the control. Therefore, we speculated that the different expression of GaILDH, GalUR and DHAR was the key factors for decrease of AsA after bagging. Bagging on A. eriantha can effectively improve the appearance and flesh color of the fruit, improve the ornamental value of the fruit, and has little effect on the sugar and acid content of the fruit. Although the AsA content was reduced, the AsA content (> 1250 mg/100 g) was still at a high level.