Modifications of Kyoho grape berry quality under long-term NaCl treatment

Different concentrations of a sodium chloride spray were applied to the grapevine cultivar Kyoho to determine the effects of salinity on berry quality. The fruit's fresh weight, relative water content, hardness and titratable acid were gradually enhanced with increased salt concentrations. Anthocyanin and soluble solids increased after treatment with moderate salinity (20 and 60 mM); however, the results were reversed under high salinity (100 and 150 mM). The soluble sugars glucose, fructose and sucrose increased after treatment with moderate salinity, whereas glucose and fructose declined under high salinity. For the six organic acids tested, their total levels were elevated by salinity, which increased the production of tartaric and malic acids. The aroma of the berry was extremely sensitive to salinity and showed a considerable decline in abundance and variety at 20 mM NaCl. In summary, moderate salinity enhanced the overall berry quality, but decreased the aroma quality, whereas high salinity decreased the berry quality.