Influence of salt-alkali stress on quality formation of Vitis vinifera L. ‘Cabernet Sauvignon’ of wine grape

The wine grape ‘Cabernet Sauvignon’ was selected as test material, the effect of 50 mmol·L⁻¹ NaCl and 50 mmol·L⁻¹ NaHCO₃ spraying grape fruit on grape quality was investigated, the influence of proper neutral salt and alkali salt on fruit ripening and quality formation were studied. In order to provide reference basis for further study on the changes of grape fruit quality under saline-alkali condition. The results showed that both of the treatment had no significant effect on grape weight. But compared to the control, the TSS content decreased under the treatments and the TSS content was significantly lower in NaHCO₃ stress than NaCl. Moreover, both of treatment delayed the accumulation of anthocyanins and the degree was higher in NaCl stress than NaHCO₃. On the contrary, the accumulation of total acid and the content of tartaric acid and malic acid were promoted in treatments compared with control in fruit ripening (after flowering 109 days). Futherly, quantitative real-time PCR analysis showed that saline and alkaline treatment all inhibited the expression of MYBA1 and UFGT genes, which played an important role in anthocyanin synthesis and the result was consistent with the accumulation of anthocyanins, suggesting that the accumulation of anthocyanins was delayed under saline and alkaline stress due to inhibiting the expression of key genes. Therefore, the salt-alkaline treatment of the fruit was not beneficial to the improvement of fruit quality and the fruit ripening process was delayed as well.