| ‘Kyoho’grape was used to elucidate the effects of different ways of NaCl treatments on berry quality.The treamments included NaCl foliar spray,root watering and partial root watering.In oder to further disclose the mechanism underlying the improvement of berry quality caused by NaCl application of partial roots,Na transportation,vine injury and distribution of carbon and nitrogen were determined using the root-split Cabernet Sauvignon grapevines.The main findings are as follows:1.Long-term foliar spraying of NaCl with different concentrations significantly increased the Na~+content of the fruit.Low(20 m M)and medium concentrations(50 mM)concentrations of NaCl did not have a significant effect on fruit growth,but high concentrations(100 and 150 mM)of salt imparted different effects on fruit growth before and after veraison.Medium and low concentrations,especially 50 mM,significantly increased anthocyanin accumulation,soluble solids content and solid-acid ratio at late developmental stages;in contrast,high concentrations of salts reduced content of anthocyanins and soluble solids,produced small effects on acidity,and largely decreased the ratio of TSS and acidity.Different concentrations of salt treatments significantly reduced the total aroma type and concentration of fruits;the esters in fruits were sensitive to salt,and salt treatment increased(E)-2-hexen-1-ol and(E)-4-hexene 1-alcohol content.2.Long-term low-concentration NaCl treatment of roots increased the content of Na~+and Cl~-in fruits and significantly decreased K~+content.The quality analysis showed that long-term low-salt treatment significantly reduced the anthocyanin content of the peel;slightly reduced the TSS content of the pulp,and significantly reduced the glucose and fructose content;by contrast,the titratable acid,tartaric acid,and malic acid responded to salt treatment in a different manner before and after veraison.Long-term low-salt treatment significantly reduced the fruit ABA content.The transcriptome analysis showed that long-term low-salt treatment significantly reduced the number of differentially expressed genes before and after veraison,affected different types of genes at veraison and postveraison,and negatively regulated the expression of mature-induced genes.3.Root partition salt treatment increased the Na~+and K~+content in fruits,and promoted the accumulation of anthocyanins in grape peels.Compared with the control,the non-uniform salt treatment increased the content of soluble solids in the fruit,reduced the titratable acid content,increased the sugar-acid ratio of the fruit,and enhanced the fruit flavor.The glucose and fructose content in the fruit was increased significantly,and the organic acid content was decreased.At the same time,non-uniform salt treatment significantly increased the type and concentration of volatile aroma in the fruit.4.Root partition salt treatment revealed that the concentration of Na~+accumulation in the roots and leaves of the grapes resulting from unilateral root salt treatment(0/50 mM,0/100 mM)was significantly lower than that of the corresponding bilateral salt treatment(50/50 mM,100/100 mM).Ion content and ion flow analysis indicated that Na~+absorbed from the processing side can pass through the non-treated side.Analysis of chlorophyll content,conductance,MDA,and chlorophyll fluorescence parameters showed that the non-treated lateral roots were not significantly injured and could alleviate the degree of injury on the treated side.The bilateral salt treatment significantly reduced the nitrogen fertilizer use efficiency.Compared with the non-salt control,the 50 mM unilateral salt treatment reduced the nitrogen fertilizer utilization rate,while the 100 mM unilateral salt treatment increased the nitrogen fertilizer utilization rate.Bilateral salt treatment,especially 100 m M salt stress,was not conducive to N-distribution rate of leaf and root,but promoted the distribution of N to perennial stems,favoring N storage.Unilateral salt treatment promoted the distribution of N to leaf and annual stem growth organs,and reduced the storage of perennial stem N;the N-distribution rate on the non-treated side was not significantly affected by salt treatment.Bilateral salt treatment is not conducive to the distribution of C to the leaves,and unilateral salt treatment can relieve the decline of leaf C distribution.Treatment with 100 mM single and double side was not conducive to C storage in perennial stalks,whereas 50 mM unilateral treatment,especially bilateral treatment promoted storage of C.Unilateral salt treatment can increase root C distribution. |
