Effects of nutrient solution management modes on fruit production and quality of tomatoes grown in extremely root restriction

•Nutrient solution management is important for tomatoes grown in root restriction.•831 metabolites were identified by metabolome analysis in tomato fruits.•Increasing nutrient solution EC by adding NaCl could improve tomato fruit quality.•Levels of carbohydrate, tricarboxylic acid, and volatile were increased by NaCl.•Low drainage promoted Ca and Mg accumulation in tomato fruits.